DESC:FIELD OF THE INVENTION
The present invention in general relates to agricultural drone systems and drones. More particularly, the present invention relates to the methods and system for a tethered drone system configured for continuous power supply and precision agrochemical delivery, suitable for large-scale and sustained crop spraying, granular nutrient distribution, plant health monitoring, and field surveillance. More so, the present invention finds its applications in agriculture for continuous payload distribution (liquids, granules, seeds, etc), powered flight, and dynamic tether management to enhance field operations. Such a tethered drone system comprises a drone system controller, multiple support drones, and an operational drone. A tethered aerial drone system is created when the support drones are connected to the tether at various points along its length. The invention involves a tethered aerial delivery system, wherein support drones are strategically connected along the tether line to lift and guide it across varying topographies, thereby enabling uninterrupted aerial operations while avoiding ground-level obstacles such as trees, uneven terrain, or infrastructure.
The system employs a multi-channel tether that facilitates the delivery of various agro-inputs including liquids, granules, foams, powders, seeds, fertilizers, and gases. The operational drone, powered continuously via the tether, can carry out precision spraying, granular distribution, or fumigation in a single flight cycle. Further, the system is equipped with real-time obstacle detection and environmental sensors to adapt its operations based on surroundings — enhancing both safety and effectiveness in agricultural applications.
The tether is lifted in the air by the multiple support drones, so as to avoid or bypass obstacles and adapt to the terrain variation, thus greatly expanding the horizontal space that can be reached by the tethered support drones and its payload.
BACKGROUND OF THE INVENTION
The subject matter discussed in the background section should not be assumed to be prior art merely because of its mention in the background section. Similarly, a problem mentioned in the background section or associated with the subject matter of the background section should not be assumed to have been previously recognized in the prior art.
Drones, also known as unmanned aerial vehicles, or UAVs, have a long history and have seen a sharp increase in use in recent years. With the improvement in the technology, the size of the drones has been reduced allowing the drones to be used in various fields, such as drones are utilised for package deliveries, medical support, and film production, etc.
Drones have made it possible to visit hazardous, as well as locations and places that are difficult for people to reach, including regions at enormous heights, or unsafe locations due to biological threats or physical limitations.
Conventional agricultural drones that are being currently used in the agricultural field often carry heavy batteries (which is about ~50% of weight of the drone), which severely impacts the payload carrying capacity of the drone, limiting it to 10–25?kg and flight time of approx. ~20 minutes, based on which it will take around 20–30 battery swaps for an agricultural drone to cover small field area of approx. 1?acre.
Further, the weight and volume of the battery pack that powers the aerial drone may restrict its applicability for specific jobs and in particular settings. Using a tether connected to an electrical power source can help reduce the constraints of a battery pack, but the weight and location of the tether may still have an impact on the aerial drone's ability to operate and change position.
Therefore, existing tethered drones may provide a short solution related to continuous power supply but suffer from tether weight, tether drag, entanglement at the ground, and limited payload flow capabilities over a long distance, avoidance and entanglement of tether to obstacles, problems in handling the curvature of the tether for continuous supply of components, and power to the operational drone, lacking ability to dynamically manage the tether configuration and position, movement of the drones, and cannot provide a continuous supply of liquid or solid payload continuously over a large distance without the above-mentioned problems.
The use of drones in agriculture, especially for spraying pesticides, fertilizers, and monitoring crop health, has gained significant traction in recent years. However, conventional battery-powered agricultural drones suffer from:
• Limited flight times,
• Payload constraints,
• Inability to switch between liquid and solid applications,
• Downtime during battery recharge or payload refills.
While tethered drones overcome flight time limitations by drawing power from the ground, existing solutions are not adapted for dual-payload dispensing or synchronized power-material delivery required in agriculture-specific tasks like:
• Field-level variable rate spraying,
• Seed or micronutrient distribution,
• Continuous crop monitoring.
Therefore, there is a pressing need for a smart, scalable, and tethered drone platform and system that can support sustained agricultural operations without interruption, deliver both liquid and solid agro-inputs, and enable real-time sensing and feedback.
There have been several attempts throughout the years to use drones in the agricultural industry. For instance, Guice's U.S. Pat. No. 6,653,971 reveals a system and method for identifying airborne plant material, such as pollen and mould spores, as well as flying insects and birds and categorising them according to their potential harm to field crops, livestock, or other assets inside a protected volume or area. To identify if the detected items of interest are dangerous, innocuous, or useful, radiation from lasers, radar, and other sources may be utilised to illuminate at least a perimeter around the assets that need to be secured. Radiation returns from these sources can then be monitored and sent into a pattern classifier. If the objects are found to be harmful (pests), various measures can be taken to remove the harmful objects controlled by radiation suggestion, including laser, microwave or other radiation triggers pulses strong enough to at least weaken them, or mechanical measures as controlled drones to drench pests with a propeller or spray limited insecticides in the pest area.
Conventional technologies, such as the one disclosed in PCT publication WO2018034578A1 which disclose drones, which are tethered to each other to achieve the height/ length needed to access the surroundings. But, the problem with the existing drones is that tethering of the drones must be done on the ground before the entire tethered drone system is ready to fly. In addition to that, there is a need of continuous power supply to individual drone, failing of which, may result in failure of the system. The power supply to the tethered drones is provided through a power cable that is connected to all tethered drones in the system. Employing power cables to power the drones that would increase load on the drones as the number of drones are increased, and a higher altitude is gained. This results in the drones consuming more power thereby reducing the efficiency of the tethered drone system. Furthermore, the PCT document is silent with respect to the tether entanglement risk, as well as the problems and struggles in flight path of the tether drone system due to the tether.
The cited document fails to disclose or suggest any mechanism for transporting payload components of varying physical forms (e.g., solid, liquid, granular, or seed-based materials) over extended distances without necessitating replacement or modification of the tether. Additionally, it does not address the provision of a continuous or uninterrupted supply of such payload components. Moreover, the structural integration of the drone with the tether adversely affects the reeling and unreeling process, resulting in non-uniform tether deployment and undesirable alterations in the tether's three-dimensional geometry and curvature during operationFurther, these patents and publications do not describe an easy-to-use and efficient tethered drone for use in, for example, agriculture, construction or other fields. Additionally, these patents and publications do not describe a tethered drone system and tethered drones that provide electronic communication to the drones and provide real-time information about objects and environmental conditions around the drones.
Additionally, conventional tethered drone systems are inherently limited in terms of the number of drones that can be simultaneously supported and the maximum operational altitude achievable due to tether tension and control constraints. Moreover, publicly available tethered drone systems and drones lack integrated mechanisms for detecting and preventing tether entanglement, as well as inter-drone coordination protocols necessary to avoid cable crossing or tangling during dynamic aerial operations. Currently available systems lack ability to dynamically manage tether configuration, and cannot supply liquid or solid payload continuously via tether to a large distance.
Based on the above, an alternative solution is needed that can address such limitations by providing a simple and efficient system.
Therefore, the present invention seeks to develop an advanced tethered drone system capable of covering a broader operational range while maintaining stability and efficiency. The invention provides a tethered drone system and an aerially supported tether deployment method ("tether-on-the-fly") designed to enable smooth, uninterrupted tether movement, while minimizing the risk of entanglement or obstruction during flight. In contrast to the existing prior art, which lacks any effective mechanism for enabling smooth and controlled tether deployment and retrieval, the present invention provides a novel solution through the integration of a pass-through loop support drone. This drone is specifically configured to dynamically regulate the tether path during reeling and unreeling operations. By actively guiding and stabilizing the tether in real-time, the support drone minimizes abrupt directional changes, reduces mechanical stresses on the tether during operation, and substantially eliminates the risk of entanglement commonly observed in tethered drone systems. Consequently, the tether is maintained in a stable, controlled three-dimensional trajectory throughout the reeling and unreeling process, thereby enhancing the overall operational reliability of the system.
The system further ensures continuous and reliable operation, whether for power transmission or payload delivery, and significantly enhances the overall efficiency, safety, and mechanical integrity of tethered drone systems. Thus, the present invention overcomes the limitations of the prior arts and provides a technically superior solution for smooth, uninterrupted tether management in various operational environments.
Furthermore, during extended aerial spraying operations over large agricultural fields, the tethered drone system, configured to distribute various agro-inputs such as granules, liquid fertilizers, liquids, foams, seeds, and other materials via designated conduits within a tether or multichannel tether, may experience residue accumulation within the internal channels of the tether. Over time, such accumulation can result in partial or complete blockages, thereby disrupting the continuous material flow and potentially damaging the internal conduit structures of the tether.
To prevent this, the present invention further provides tether which is internally coated with a non-stick material, and the tethered drone system also incorporates an anti-clogging mechanism comprising periodic internal flushing using pressurized air or liquid pulses, and/or vibration-inducing system aligned along the tether to dislodge lodged materials. This configuration ensures smooth and continuous material flow through the tether channels, enhances operational reliability, and eliminates the need for frequent manual cleaning or system interruption, a vibration-assisted flushing system is periodically activated to clear residues and maintain free flow. This ensures uninterrupted delivery, reduces maintenance frequency, and extends the usable lifetime of the tether. Such a novel and inventive feature as disclosed in the present invention is not part of the prior art documents.
The present invention satisfies the existing needs, as well as others, and generally overcomes the deficiencies found in the prior art.
No prior art system discloses or enables a powered, continuous multi-channel transfer of liquids and granules in conjunction with dynamic tether tilt and curvature control—achieved through actively coordinated support drones, while also sustaining indefinite operational duration of the operational drone, all without encountering issues of tether entanglement or obstruction along the flight path.
OBJECTS AND ADVANTAGES OF THE INVENTION
The principal object of the present invention is to provide a novel and effective tethered drone system demonstrating high efficiency and effective functioning in the application of agricultural practices.
Another object of the present invention is to provide a novel and advanced tethered drone system capable of continuous aerial operation, particularly suited for agricultural applications such as precision spraying, nutrient distribution, and real-time crop monitoring over large field areas.
Another object of the present invention is to provide a novel and effective tethered drone system comprising a plurality of support drones, each operatively connected to the tether, and configured with inter-drone coordination mechanisms to prevent tether crossing or entanglement during aerial operations
Another object of the present invention is to provide a novel and effective tethered drone system for the effective supply of the granules, liquids, foams, gases, powders to crops, and electricity and/or electronic communications to operational drone.
Another object of the present invention is to provide a novel and effective tethered drone system comprising an operational drone and the multiple support drones.
Another object of the present invention is to provide a novel and effective tethered drone system wherein the support drones actively lift and manage the tether line to create an obstacle-free aerial pathway for the operational drone.
An object of the present invention is to provide a novel and effective tethered drone system with integrated capabilities for aerial spraying, broadcasting of agrochemicals (such as pesticides, herbicides, granules, and liquid fertilizers), and subsurface seed injection, thereby enabling comprehensive agricultural field operations.
Another object of the present invention is to provide a tethered drone system equipped with docking and undocking mechanisms for battery and payload exchange, thereby facilitating extended operation and modular task flexibility.
Another object of the present invention is to provide a method and system for a tethered drone that autonomously follows a mobile base station to maximize operational range and reduce downtime.
Another object of the present invention is to provide a tethered drone system capable of delivering multiple material types—such as granules, liquids, foams, powders, liquid fertilizers, and gases—through a multi-channel tether that enables simultaneous or sequential application.
Another object of the present invention is to provide a tethered drone system integrated with real-time obstacle detection and avoidance mechanisms to ensure uninterrupted operation across varied terrain and vegetation densities.
Another object of the present invention is to provide a system and method for a powered, parasitic, multi-unit airborne tether network and its associated software logic for automated tether laying, route optimization, and coordinated following.
Another object of the present invention is to provide a tethered drone system comprising intelligent software-controlled mechanisms for reeling and unreeling of airborne tether during dynamic field operations.
Another object of the present invention is to provide a multi-capability tethered drone platform comprising auxiliary “minion” surveillance drones equipped with above-foliage, in-foliage, under-foliage, and ground-level monitoring capabilities to assist the main applicator drone in performing precision spot treatments and optimizing dosage delivery.

Another object of the present invention is to provide a tethered drone system capable of real-time soil nutrient parameter detection and responsive adjustment of the tank mix formulation via a customizable applicator supply tank, thereby enabling precision agriculture.
Another object of the present invention is to provide a tethered drone equipped with retractable or extendable tubes for the targeted transport and delivery of matter across varying heights and locations.
Another object of the present invention is to provide a tethered drone system comprising a plurality of sensors mounted on support drones to collect and relay real-time data related to ground topology, nearby objects, environmental conditions, and operational activities, thereby allowing live adjustment and navigation to avoid obstacles and optimize application.Another object of the present invention is to provide a system and/or method involving a tethered drone, wherein the tether is primarily supported and managed by a plurality of support drones, and is not intended to serve as a backup or primary load-bearing structure for the operational drone.
Yet another object of the present invention is to provide a system and/or method wherein the support drones are configured to move laterally relative to one another, up to a predefined limit, to dynamically adjust and maintain tension in the tether, thereby minimizing tether curvature and avoiding obstacles.
A further object of the present invention is to provide a system and/or method wherein at least one drone is designated specifically for lifting and suspending the tether to ensure an unobstructed and elevated tether path during operation.
Another object of the present invention is to provide a tethered drone system wherein an operational drone receives continuous electrical power and payload components via a multichannel tether from a ground-based base station, eliminating dependence on onboard batteries and manual payload replacement.
Another object of the present invention is to enable the simultaneous and uninterrupted delivery of multiple types of payloads—including but not limited to liquids, granules, seeds, powders, foams, and gases—through separate functional channels within the multichannel tether.
Another object of the invention is to provide a system comprising multiple support drones configured to dynamically lift and manage the tether in real-time, thereby preventing entanglement with ground obstacles, vegetation, and environmental structures.
Another object of the present invention is to introduce pass-through loop support drones and fixed-attachment support drones that maintain three-dimensional tether geometry, enabling smooth reeling and unreeling operations without tether drag, jerk, or crossover events.
Another object of the invention is to provide a sensor-integrated entanglement detection and prevention mechanism, employing fusion of sensors including but not limited to GPS, INS, ultrasonic, LiDAR, and gyroscopic data to dynamically adjust the spatial distribution and behavior of the support drones and tether.
Another object of the invention is to provide a smart base station that regulates tether length adjustment through automated reeling/unreeling mechanisms based on drone positioning, field layout, obstacle detection, and operational needs.
Another object of the invention is to enable the autonomous or remote-controlled functioning of the tethered drone system using onboard sensors, telemetry modules, and drone-to-drone and drone-to-base station communication.
Another object of the invention is to incorporate an anti-clogging mechanism using mechanical vibrations, flow sensors, and non-stick materials within the tether and nozzle to prevent residue build-up and ensure uninterrupted material flow.
Another object of the invention is to integrate a multifunctional, adaptive nozzle system in the operational drone to allow selective discharge of various materials from a common outlet with adjustable spray or delivery modes.
Another object of the invention is to improve operational safety and mechanical integrity by elevating the tether using aerial support, avoiding contact with terrain irregularities or low-hanging objects.
Another object of the invention is to support extended and potentially perpetual aerial operation of drones by using tether-based power delivery, overcoming the flight duration limitations of conventional drones.
Another object of the present invention is to facilitate cooperative interaction between operational drones, support drones, minion surveillance drones, and the base station, thereby enabling high-precision, scalable, and efficient aerial applications across diverse environments.
Another object of the invention is to provide minion surveillance drones for real-time crop health analysis, soil monitoring, and pest detection, enabling precise and data-driven payload delivery.
Another object of the invention is to provide a system that supports customized and variable-rate nutrient or pesticide application, using onboard sensors and dynamic field analysis.
Another object is to reduce manual intervention, operational downtime, and maintenance frequency by enabling a fully integrated, intelligent, and automated aerial application platform.
Some or all these and other objects of the invention can be achieved by way of the invention described hereinafter.
ADVANTAGES OF THE PRESENT INVENTION
1. Improved Terrain Adaptability and Obstacle Avoidance:
The tether is dynamically elevated and managed by multiple support drones, allowing the system to effectively avoid or bypass physical obstacles and adapt to varying terrain conditions during operation.
2. Extended Horizontal Operational Reach:
The coordinated movement and tether support mechanism significantly expand the horizontal range that the tethered drone and its payload can access, enabling efficient coverage of large agricultural fields.
3. Uninterrupted Aerial Operation:
The tethered support drones receive continuous electrical power through the tether, allowing for virtually indefinite flight duration, in contrast to conventional drones limited by onboard battery or fuel constraints.
4. Versatile Multi-Type Payload Delivery:
The system enables the simultaneous or sequential delivery of various substances—such as granules, liquids, foams, powders, gases, and liquid fertilizers—through a multi-channel tether, enhancing utility across diverse agricultural applications.
5. Sub-Canopy Delivery Capability:
An extendable and retractable delivery tube allows precise dispensing of materials beneath tree canopies or dense foliage without risking entanglement or collision, enabling targeted application.
6. Flexible Control Options:
The system may be operated remotely by a human user or function autonomously via onboard sensors and pre-programmed instructions, ensuring adaptability to different operational requirements and reducing manual intervention.
7. Sustained Support Drone Flight:
The continuous power supply provided through the tether ensures that multiple support drones can remain airborne for extended periods, thus supporting long-duration tasks without interruption.
8. Enhanced Tether Management and Stability:
Integrated tether support arms help guide and stabilize the tether in real time, minimizing slack, sagging, or entanglement and maintaining a uniform tether path during aerial operations.
9. Autonomous Obstacle Avoidance:
The system includes real-time sensing and path-adjustment features to detect and avoid obstacles near the working drone, ensuring uninterrupted and safe task execution in complex field environments.
Some of the other advantages of the present inventio are as under:
1. Continuous Multi-Type Payload Delivery:
o The present invention enables the continuous transport and delivery of various types of payload components (e.g., liquids, granules, seeds, powders, foams, gases) through a multi-channel tether, eliminating the need to change the tether or interrupt operations, thereby enhancing agricultural efficiency.
2. Powered Flight Without Battery Limitations:
o By employing a tethered power supply, the invention eliminates the limitations imposed by onboard heavy battery packs, significantly increasing the flight duration and payload capacity of the operational drone and reducing the need for frequent battery replacements or charging interruptions.
3. Dynamic Tether Management Using Support Drones:
o The invention introduces multiple pass-through loop support drones that dynamically manage the tether in real-time during flight, reeling, and unreeling operations, along with fixed support drones. These drones lift and stabilize the tether along its length to maintain an optimal path and avoid obstructions, uneven terrain, or entanglement.
4. Smooth Reeling and Unreeling of Tether:
o The integration of support drones ensures smooth and uniform tether deployment and retrieval, maintaining a consistent three-dimensional tether curvature. This overcomes the common issues of tether drag, jerks, or twisting seen in conventional tethered drone systems.
5. Entanglement Avoidance and Obstacle Bypass:
o The invention provides an effective solution to the risk of tether entanglement by lifting and guiding the tether above ground and environmental obstacles, thus ensuring uninterrupted and secure operation even over uneven terrains.
6. Real-Time Environmental Sensing and Adaptation:
o The system is equipped to detect and respond to objects and environmental conditions (in front, behind, and laterally) using onboard sensors, allowing real-time path adjustment and obstacle avoidance during operation.
7. High Horizontal Reach and Operational Flexibility:
o With the tether supported aerially by multiple drones, the system significantly expands the horizontal coverage area of the operational drone, allowing payload delivery over large fields or construction sites without tether replacement or repositioning.
8. Enhanced Safety and Mechanical Integrity:
o The controlled guidance of the tether and avoidance of sudden stresses during operation improves the mechanical integrity and lifespan of the tether, ensuring safer and more reliable drone performance.
9. Indefinite Operational Duration:
o By combining continuous power supply with dynamic tether management, the present invention supports extended or potentially indefinite operation of the tethered drone, surpassing the limited duty cycles of battery-operated systems.
10. Multi-Drone Communication and Coordination:
o The system supports a plurality of drones that communicate electronically, enabling coordinated tether handling and adaptive operational control in real-time.
11. Application Versatility:
o The present invention is adaptable for multiple fields, particularly including agriculture, and other domains that require robust and continuous drone operation over extended areas.
12. Self-Cleaning / Anti-Clogging mechanism
o The present invention incorporates different vibration mechanisms, including but not limited to air jets, vibration mechanism to avoid clogging from granules, foams, or viscous liquids and also incorporates the non-stick inner surface coatings in order to minimize residue build-up. This ensures uninterrupted delivery of required payload, reduces maintenance frequency, and extends the usable lifetime of the tether.
13. Multifunctional adaptive nozzle geometry suitable for different material types
o The present invention incorporates Multifunctional adaptive nozzle capable of dispensing various materials (solids, liquids, foams, seeds, granules) from a common outlet, with adaptive control mechanisms.
14. Integration of Surveillance and Application Functions using minion surveillance drones which provide real-time crop and soil analytics, allowing targeted delivery of inputs and payloads along with real-time field optimization.
15. Overcoming Prior Art Limitations:
o Unlike conventional systems (e.g., WO2018034578A1), the invention:
? Avoids overload from inter-drone power cables,
? Maintains tether stability and curvature during motion of drone/tether,
? Provides multi-type payload delivery via tether,
? Includes entanglement detection and avoidance, along with smart reeling/unreeling operation and mechanism.
? Includes anti-clogging mechanism of payload.
? Includes multifunctional nozzle system for application of different payload material using common outlet.
? Includes operations of surveillance drone for effective functioning of the tethered drone system and the operational drone.
SUMMARY OF THE INVENTION
The present invention relates to a novel tethered drone system and its specialized applications in the field of agriculture. The system includes a plurality of support drones and a working drone, coordinated via a multi-channel tether designed for delivering various agricultural inputs such as granules, liquids, foams, powders, fertilizers, and gases. The invention provides significant improvements in aerial coverage, operational continuity, obstacle avoidance, and precision delivery in diverse terrain conditions.

This summary is provided to introduce certain innovative aspects of the invention and does not purport to define the essential features or limit the scope of the subject matter claimed herein.Accordingly, a principal aspect of the present invention is to provide a novel and highly efficient tethered drone system specifically designed to enhance the effectiveness and operational reliability of various agricultural practices.
The present invention discloses a tethered unmanned aerial vehicle (UAV) configured for agricultural applications, which enables uninterrupted operation of an aerial applicator drone (i.e., operational drone) through continuous supply of electrical power and agricultural payloads (including but not limited to granule, liquid, foams, seeds, powder, liquid fertilizers and gases) via a tether (including but not limited to multichannel tether). The invention is particularly directed to overcoming the limitations of conventional battery-powered drones and existing tethered drone systems, by introducing a novel and inventive mechanism for dynamic tether maneuverability and management through the use of tether drone system comprising operational drone, base station, multiple support drones, tether, Minion surveillance drones, entanglement detection/prevention system, etc thereby enabling large-scale, efficient, and obstacle-free aerial operations in agricultural fields.
Accordingly, the present invention relates to a tethered drone system comprising a drone system controller or a base station, an operational drone and multiple support drones connected via tether.
In an aspect, the present invention provides a tethered drones system comprising:
a) a drone system controller or a base station;
b) an operational drone; and
c) multiple support drones, wherein, the supporting drones are connected via tether either with direct attachment or indirect attachment.
In one another aspect, the present invention provides a tethered drone system comprising:
a) a drone system controller or base station for managing and coordinating drone operations;
b) an operational drone configured to perform designated aerial tasks; and
c) a plurality of support drones, each of which is connected to the system via a tether, either through direct attachment to the operational drone or indirect attachment through other support drones or intermediate mechanisms.
In another aspect, the present invention provides a novel and effective tethered drone system comprises the multiple support drones each tethered by a tether.
In another aspect, the present invention provides a tethered drone system comprising a plurality of support drones, wherein each of the support drones is operatively coupled to the tether either through a fixed attachment mechanism or via a pass-through loop configuration that enables dynamic positional adjustment along the length of the tether.
In another aspect, the tethered drone system comprises a plurality of support drones, wherein the support drones with fix attachments to the tether are both mechanically and electrically connected to the tether at specific non-insulated contact points, referred to as “power docks.” These power docks function as secure attachment points that provide both structural support and electrical power supply to the support drones.
In yet another aspect, the plurality of support drones with fixed attachment to tether in the tethered drone system are configured to draw electrical power directly from the tether via the aforementioned power docks, thereby enabling sustained aerial operation without reliance on onboard energy storage systems.
In another aspect, the tethered drone system comprises a plurality of support drones, wherein at least some of the support drones are configured with a pass-through loop mechanism. The loop forms an indirect connection between the support drone and the tether, allowing the drone to support the tether’s elevation, manage its position dynamically, and assist in controlling the effective tether length during deployment and operation.
In another aspect, the tethered drone system comprises a plurality of support drones, wherein the support drones utilizing the pass-through loop mechanism/configuration are further configured to receive electrical power wirelessly, without requiring direct electrical contact with the tether.
In another aspect, the wireless power transfer system used by the pass-through loop support drones may include, but is not limited to, inductive charging technology employing inductive coils to enable efficient wireless power reception from the tether or a nearby power source.
In another aspect, the tethered drone system comprises one or more support drones operatively connected to the tether at designated locations, wherein at least one support drone is configured to provide an anti-clogging function by inducing mechanical vibrations in the tether.
In another aspect, wherein the mechanical vibrations in the tether may be generated using piezoelectric actuators, vibration motors, or equivalent means integrated within the drone attachment structure or power dock interface. Such vibrations are used to dislodge the clogged/residue buildup of the materials such as granules, seeds, etc, within the channels of the tether during the operation of the tethered drone system.
In another aspect, the drone system controller or base station is configured to monitor payload flow and automatically activate vibration or flushing sequences upon detecting potential clogging conditions. The drone system may further include embedded sensors to detect flow rate anomalies, pressure build-up, or material stagnation within the tether, enabling real-time corrective action.
In another aspect, wherein tether comprises of multichannel tether, sensors, power-dock points, etc.
In another aspect, the tether of the present invention can be selected as multi-channel tether.
In another aspect, wherein the multi-channel tether is configured to support multiple functional channels for simultaneous power transmission and delivery of different types of payloads.
In another aspect, the multichannel tether is capable of delivering multiple types of payloads—such as liquids, granules, seeds, powders, foams, gases —simultaneously and continuously over extended distances.
In another aspect, the present invention provides multifunctional nozzle system for drones capable of dispensing various materials (solids, liquids, foams, seeds, granules) from a common outlet, with adaptive control mechanisms that adjusts accordingly to the particle size, flow rate, or spray pattern based on the material.
In another aspect, the multifunctional nozzle system comprises of various sensors including but not limited to flow rate sensors, blockage detectors, or material-type recognition sensors to adjust for particle size, flow rate, or spray pattern based on the material used.
In another aspect, the present invention provides a novel and effective tethered drone system for the effective supply of the granules, liquids, foams, gases, powders to crops via multi-channel tether and also provides electricity and/or electronic communications to multiple drones.
In another aspect, the present invention provides a novel and effective tethered drone system wherein, the multiple support drones effectively lift the tether and provides obstacle free path for an operational drone.
In another aspect, the present invention provides a novel and effective tethered drone system having integrated capability for spraying, broadcasting (Pesticides, Granules, Herbicides, Liquid Fertilizers) and subsurface seed injection.
In another aspect, the present invention provides a system and/or method involving a tethered drone for multi type (granule, liquid, foams, seeds, powder, liquid fertilizers and gases, multiple liquids) delivery via a tether by the utilization of multi-channel tether.
In another aspect, the present invention provides a system and/or method comprises a tethered drone system for tether management as well as obstacle avoidance during the operations.
In another aspect, the present invention provides a system and/or method involving a tethered drone to detect soil nutrient parameters and adjust tank mix for optimal mix of nutrients through customized applicator supply tanks.
In another aspect, the present invention provides a system and/or method involving a tethered drone, wherein, tether is for providing support to the supporting drone which is infeasible and are not meant for backup for the working drone.
In another aspect, the present invention provides a system and/or method involving a tethered drone configuration, wherein the support drones are capable of horizontal displacement relative to one another up to a predefined limit, thereby generating controlled tension within the tether. This controlled tension facilitates obstacle avoidance and enables dynamic management of tether curvature in accordance with operational and environmental requirements.In another aspect, the present invention provides a system and/or method, wherein, a drone is provided for lifting the tether attached to the tethered drone.
In another aspect, the present invention provides pilot drones configured to perform surveillance and supply power to the tethered drone system, thereby ensuring stable and efficient operation of the primary working drone..
In another aspect, the present invention provides a system and/or method involving a tethered drone comprising a plurality of sensors integrated into the support drones. These sensors are configured to deliver real-time data regarding ground conditions, nearby objects, and surrounding environmental parameters to enable dynamic operational adjustments by the operator or autonomous control system. Additionally, embedded sensors within the tether are adapted to detect flow rate anomalies, pressure build-up, or material stagnation, thereby facilitating the activation of an anti-clogging mechanism to ensure uninterrupted material delivery.In another aspect, the present invention provides a tethered drone system and drone for agricultural applications, wherein such a system comprises essential components including:
i) an operational drone configured for application of payloads over the field;
ii) a plurality of support drones, which comprises both fixed support drone (electrically powered via direct tether contact at power dock) and pass-through loop-support drone (powered via inductive charging), for suspending, dynamic tether management, anti-clogging mechanism and maneuvering the tether during operation;
iii) a multichannel tether configured with at least three internal channels for transmitting electric power, liquids, and granular materials/seeds, etc.;
iv) a base station incorporating a reeling/unreeling mechanism, power supply, reservoirs, pumps, and controllers for efficient and coordinated working of the tether drone system;
v) a reeling/unreeling assembly for adjusting the tether length based on the operational drone’s field coverage requirements, as well as other factors such as to avoid the no-fly zones, obstacles, manage the height restrictions, entanglement avoidance;
vi) Pass through loop support drones allow free tether movement and receive power via wireless induction technology.
vii) one or more minion surveillance drones, are independently operable without the tether and configured for field monitoring, pest detection, and soil analysis; and;
viii) an entanglement detection and prevention mechanism, configured to control the positional and spatial distribution of the supporting drones and tether geometry/configuration in real time during its operation.
In another aspect, the present invention provides a tethered drone system and drone specifically designed for agricultural applications, wherein the system comprises the following essential components:
i) an operational drone configured for the aerial application of payloads such as seeds, granules, liquids, and fertilizers over agricultural fields;
ii) a plurality of support drones, including both fixed-type support drones (electrically powered via direct tether connection at designated power docks) and pass-through loop-type support drones (powered via inductive charging), adapted for suspending the tether, managing dynamic tether movement, assisting in anti-clogging mechanisms, and maneuvering the tether during operation;
iii) a multi-channel tether comprising at least three internal channels configured for the concurrent transmission of electrical power, liquid formulations, and granular materials or seeds;
iv) a base station equipped with a tether reeling/unreeling mechanism, integrated power supply, reservoirs, pumps, and control units for managing and coordinating the overall functioning of the tethered drone system;
v) a reeling/unreeling assembly operable to adjust the tether length in real-time based on the operational drone’s field coverage area, obstacle mapping, no-fly zones, altitude restrictions, and entanglement avoidance logic;
vi) pass-through loop-type support drones configured to enable unimpeded tether passage while receiving power wirelessly through inductive power transfer technologies;
vii) one or more minion surveillance drones, untethered and independently operable, configured for auxiliary functions such as field monitoring, pest detection, foliage inspection, and soil condition analysis; and
viii) an entanglement detection and prevention mechanism, operable to monitor and control the spatial arrangement and positional coordination of the support drones and tether geometry in real time, thereby mitigating risks of entanglement during deployment and operation.
In another aspect, the present invention provides enhanced maneuverability and dynamic tether management, achieved through coordinated operation of the support drones in conjunction with an integrated entanglement detection and prevention mechanism.In another aspect, the present invention provides the system as mentioned above which ensures that the tether remains suspended in air, free of obstacles and entanglements, and is capable of dynamically adjustable three-dimensional (3D) curvatures to reach the desired field/target locations.
In another aspect, the present invention provides the entanglement prevention mechanism, which is guided by geo-positional data (e.g., GPS), drone-to-drone communication, and obstacle mapping to maintain safe tether paths and to prevent tether crossovers and contact with field obstructions or designated no-fly zones, or other restrictions etc.
In another aspect, the present invention provides an entanglement prevention mechanism governed by geo-positional data (e.g., GPS), inter-drone communication protocols, and real-time obstacle mapping. This mechanism ensures the maintenance of safe and optimized tether trajectories by preventing tether crossover, avoiding physical contact with field obstructions, and respecting designated no-fly zones, altitude ceilings, and other predefined operational constraints.

In another aspect, the present invention provides uninterrupted aerial operations over extended periods and large field areas, with continuous delivery of both power and agricultural payload materials of different types, while mitigating the drawbacks of weight constraints, tether drag, and obstacle entanglement associated with conventional drone systems (tethered or untethered).
In another aspect, the present invention provides a synergistic integration of the operational drone, support drones, minion drones, multichannel tether, and base station systems, wherein their cooperative interaction facilitates precision agricultural applications through coordinated delivery, monitoring, and control functions within the tethered drone system.
In another aspect, the present invention provides an entanglement detection/prevention mechanism using GPS and other sensors to dynamically maintain tether geometry/configuration, avoid obstacles/no-fly zones, and guide tether curvature.
In another aspect, the present invention provides a reeling/unreeling mechanism controlled from the base station with various sensors (including but not limited to sensors for spooling and tension sensing), responsive to the operational drone’s position and coordinated with support drones to adapt tether length and tension, and to accordingly coordinate the process of reeling/unreeling based on the specific requirements.
In another aspect, the present invention provides a reeling/unreeling mechanism operably controlled from the base station, incorporating a variety of sensors, such as spooling sensors and tension sensors, configured to monitor and respond to the real-time position of the operational drone. This mechanism functions in coordination with the supporting drones to dynamically adjust the tether length and tension, thereby ensuring optimized tether management in accordance with mission-specific operational requirements and environmental conditions.
In another aspect, the present invention provides one or more untethered minion surveillance drones configured to independently monitor field conditions, including pest presence, soil characteristics, and crop health. These drones are operable to collect and transmit real-time data to the base station or operational drone, thereby enabling targeted intervention and treatment of specific field zones with enhanced precision.
BRIEF DESCRIPTION OF DRAWINGS:
Fig. 1 illustrates an overview of the tethered drone system (100), including the base station (105), multichannel tether (130), operational drone (140), and supporting drones (135, 137), forming the core structure of the system.
Fig. 2 illustrates the operational scenario and deployment of the tethered drone system (100) during field operations, showing coordinated aerial movement of operational and support drones over an agricultural terrain.

Fig. 3 illustrates the construction of the multichannel tether (130) used for delivery of power, data, and agricultural material (such as liquids, granules, foams, or seeds), comprising multiple internal conduits configured for diverse transmission.
Fig. 4 illustrates the fixed-type supporting drones (135, 137) rigidly attached to the tether (130) at predetermined intervals for providing structural lift and positional control of the tether path.
Fig. 5 illustrates the pass-through loop support drone (135) that permits controlled, dynamic passage of the tether (130) while maintaining lift and ensuring optimal tether routing with minimized curvature.
Fig. 6 illustrates the tether management mechanism at the base station (113), including components for reeling/unreeling, tether storage, tension management, and real-time control integration for dynamic length adjustment.
Fig. 7 illustrates the control coordination framework, including reeling/unreeling control system (113), real-time tracking sensors, and drone repositioning subsystems for managing field coverage and tether response.
Fig. 8 illustrates the entanglement detection and prevention mechanism, showing how drone-to-drone communication, GPS positional tracking, and sensor-based obstacle detection cooperate to avoid tether tangling and maintain safe flight corridors.
Fig. 9 illustrates the structure of the operational drone (140), highlighting its payload module, extended nozzle arms or tubes, onboard control unit, and integrated interfaces with the tether (130) and support drones (135, 137).
DETAILED DESCRIPTION OF THE INVENTION:
Unless otherwise specified or made clear by context, the following terms used in this specification are to be understood as described below:
Tether :The term "tether" refers to a multifunctional, multichannel flexible conduit that serves three primary roles within the tethered drone system:
1. Material Transfer Tube: The tether includes one or more internal tubular channels configured for the simultaneous transfer of multiple types of payload materials, including but not limited to liquids, granules, powders, foams, gases, and seeds. These channels may vary in material and diameter depending on the intended payload.
2. Power and Data Transmission Line: The tether further comprises electrical wires and/or optical fibers to deliver power from the base station to the operational and supporting drones, and to enable real-time data communication among system components including sensors, controllers, and drones.
3. Mechanical Suspension and Routing Medium: Structurally, the tether acts as a suspension line supported and managed by multiple support drones. It maintains geometric integrity in three-dimensional space, allowing obstacle avoidance, terrain adaptation, and dynamic path routing. The tether’s curvature and tension are actively monitored and adjusted to avoid entanglement and ensure smooth aerial operation.
The tether may also be referred to as a multi-channel tether or powered delivery tether, as it integrates payload transport, power delivery, and structural routing in a single flexible component.
Operational Drone :The term “Operational Drone” or “Working Drone” refers to the primary drone unit that carries out core functional tasks such as spraying, broadcasting, or seed injection. It is connected to the base station via the tether and is supported in operation by multiple support drones.
Support Drones :The term “Support Drones” includes drones that serve to hold, lift, guide, and maneuver the tether in three-dimensional space. These may include:
• Fixed Support Drones, which are directly powered through tether attachment.
• Pass-Through Loop Drones, which allow the tether to pass freely while receiving power wirelessly (e.g., via inductive charging).
Support drones work cooperatively to adjust tether position and avoid entanglement or collision with obstacles.
Base Station :The “Base Station” includes all ground-based infrastructure supporting the tethered drone system. This includes a reeling/unreeling mechanism, power source, reservoirs for payload materials, pumps, controllers, and communication hardware.
Minion Surveillance Drones
Minion Surveillance Drones are untethered, independently operable drones deployed for monitoring field conditions, detecting pests, analyzing soil parameters, or mapping terrain and obstructions. These drones supply situational data to the system in real-time for optimized application and navigation.
Entanglement Detection and Prevention Mechanism: A subsystem utilizing geo-positional data (e.g., GPS), drone-to-drone communication, and obstacle mapping to continuously monitor the position and movement of the tether and support drones, ensuring collision avoidance and non-crossing of tethers during operation.
In one of the embodiments, the tether 130 can be a rigid pipe or a flexible pipe.
In yet another embodiment, tether 130 can be multifunctional, multichannel, flexible tubular cable—with at least three distinct functionalities:
• Fluid/material transport (tube-like behavior),
• Power/data transmission,
• Structural/mechanical support for aerial configuration.
In another embodiment, an operational drone 140 is configured with a sprinkler (multifunctional nozzle system) 143 for delivering the necessary materials such as granules, liquid, foam, powder or liquid fertilizers. The sprinkler is configured to have multi-chamber applicator, wherein, liquids, granules, solids, powder etc. are sprayed by variable pressure as per the requirement.
In one of the embodiments, the tethered drone system 100, comprises a drone system controller or a base station 105, wherein the base station 105 is configured with a power source unit (or power supply) 107 to supply power to the drones (135, 137, 140).
In another embodiment, the multiple support drones (135, 137) are interconnected by tether 130. The tethered drone system includes an operational drone 140 that is configured as required. The supporting drones 135, 137 are connected to a ground base station 105.
In one embodiment, the drone system controller in a base station 105 includes a reservoir 109 that is configured to hold liquids ( powder, foams, gases or liquid fertilizers). The stored fluid can be used to supply fluid to an operational drone 140.
In one embodiment, the drone system controller in a base station 105 includes a reservoir 111 that is configured to hold solids (granules, seeds or similar). The reservoir for solid can be used to supply material to an operational drone 140.
In one embodiment, base station 105 comprises three chambers/compartments which includes two sections for storage of material. The first chamber is configured to hold liquid 109 (powder, foams, gases or liquid fertilizers), second chamber/reservoir 111 for solids (seeds, granules, etc). The third compartment/chamber is configured for power supply (107). The power source 107 is used to power connected support drones.
In an embodiment, a tethered drone system 100 effectively supplies granules, liquids, foams, gases, powders to crops and electricity and/or electronic communications to multiple drones.
In an embodiment, the multiple support drones effectively lift the tether 130 and provides obstacle free path for an operational drone 140.
In another embodiment, the tethered drone system 100 has an integrated capability for spraying, broadcasting (Pesticides, Granules, Herbicides, Liquid Fertilizers) and subsurface seed injection.
In another embodiment, the present invention provides a system and/or method involving a tethered drone for multi type (granule, liquid, multiple liquids) delivery via a tether by the utilization of multi-channel tether 130.
In another embodiment, a system and/or method involving a tethered drone, detect soil nutrient parameters and adjust tank mix for optimal mix of nutrients through customized applicator supply tanks.
In another embodiment, the tethered support drones 135, 137 are supplied with the electrical power through the tether 130, thus has virtually unlimited duration in air. Whereas, the duration that the existing non - tethered drones can stay in air is constrained by the capacity of the battery or the amount of the fuel it carried.
In another embodiment, a system and/or method involving a tethered drone comprising a plurality of sensors on the support drones which provide real-time information related to the ground surrounding the areas of the drones, near-by objects and environmental conditions surrounding the drones and further work performed around the drones so as to allow the operator of the drones to make adjustments in real-time.
In one of the embodiments, each of the support drones among the plurality of drones is equipped with a suite of sensors 150, which may include, but are not limited to: Global Positioning System (GPS), Assisted GPS (AGPS), Inertial Navigation Systems (INS), gyroscopes, laser sensors, optical sensors, and ultrasonic sensors. These sensors function collectively to provide real-time geo-positional awareness, attitude stabilization, and environmental mapping.
The GPS and AGPS systems enable accurate determination of the geographical location of the support drones (135, 137), while the gyroscope and INS assist in maintaining stable orientation and flight paths.
The laser and optical sensors facilitate the detection of static and dynamic obstacles in the flight path and also enable inter-drone spatial awareness, allowing each support drone to recognize and align itself relative to neighbouring drones for coordinated tether management and obstacle avoidance.In one embodiment, the multiple support drones (135, 137) are interconnected through tether segments to form a coordinated chain of tethered drones. These support drones are configured to operate in synchronization with one another to facilitate specific operational tasks, such as managing the tether path, stabilizing flight, or assisting in payload delivery.
The number of support drones deployed in the chain may be determined based on mission parameters, including but not limited to: required altitude, terrain variability, tether length, payload weight, and environmental conditions. The chain of drones ensures that the tether 130 maintains a stable configuration in three-dimensional space and avoids entanglement with the support drones (135, 137) or the operational drone 140, thereby ensuring uninterrupted operation and efficient aerial mobility of the system.

In another embodiment, a docking station is provided, which includes a platform configured to facilitate the landing, charging, and deployment of support drones (135, 137), minion surveillance drones 145, or other untethered auxiliary drones. The docking station may incorporate charging ports or wireless charging technologies (e.g., inductive or capacitive methods) for replenishing battery power when the drones are docked in idle mode. The support drones may autonomously launch from the docking station, execute assigned missions such as tether lifting or obstacle mapping, and return to the station upon task completion for recharging and system recalibration.
In one embodiment, the system and/or method involving a tethered drone comprises a plurality of support drones that are configured to translate laterally (horizontally) relative to each other up to a predefined positional threshold or hard limit. This coordinated lateral movement is intended to dynamically induce and manage tension within the tether, thereby minimizing undesired curvature, sagging, or slack in the tether line. As a result, the system can proactively avoid obstacles, maintain optimal tether alignment, and enhance operational stability and efficiency, particularly in variable or obstacle-rich terrains such as agricultural fields.In one embodiment, a system and/or method, wherein, a support drone 135, 137 is provided for lifting the tether 130 of the tethered drone system 100.
The invention has other advantages and features which will be more readily apparent from the following detailed description of the invention and the appended claims, when taken in conjunction with the accompanying drawings.
The invention is described herein in detail with the help of figures appended at the end of the specification. The figures illustrate the preferred embodiment as well as other embodiments that define the scope of the present invention. However, it may be understood that the figures presented herein are intended to exemplify the scope of the invention only. The person skilled in art may note that by no means the figures limit the scope of the invention. Any variation in the drawings by any other person will be falling in the scope of the present invention.
Throughout the specification and claims, the following terms take the meanings explicitly associated herein unless the context clearly dictates otherwise. The meaning of "a", "an", and "the" include plural references. The meaning of "in" includes "in" and "on." Referring to the drawings, like numbers indicate like parts throughout the views. Additionally, a reference to the singular includes a reference to the plural unless otherwise stated or inconsistent with the disclosure herein.
The embodiments herein and the various features and advantageous details thereof are explained more fully with reference to the non-limiting embodiments that are illustrated in the accompanying drawings and detailed in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.
In describing the embodiments of the invention, specific terminology is resorted for sake of clarity. However, it is not intended that the invention be limited to specific terms so selected and it is to be understood that each specific term includes all technical equivalents that operate in a similar manner to accomplish a similar purpose.
DETAILED DESCRIPTION OF DRAWINGS:
Figure 1: A depiction of the components of the tethered drone system 100
Figure 1 illustrates the different components of the tethered drone system 100, which comprises:
i. A base station 105 (not shown as 105) comprising source for continuous supply of power 107, payload materials (109- reservoir for liquid material; 111- reservoir for solid material);
ii. drone controller system;
iii. pumps (115, 117 for liquid and solid material) to transport the material through the tether 130;
iv. reeling/unreeling system 113;
v. tether (multichannel tether) 130;
vi. support drones (fixed attachment 137 and pass-through loop support drones 135);
vii. power dock points 160;
viii. vibration modules 155;
ix. operational drone 140; and
x. Minion surveillance drone 145.
Figure 2: illustrates the working of the Tethered Drone System, comprising:
A base station 105 comprising drone controller system, pump 115, 117, reservoirs for agricultural payload materials (for liquid – 109, for solid -111), reeling/unreeling system 113, wherein the one end of tether 130 (that can be a multi-channel tether) is connected to base station 105 for continuous supply of power and payload materials, and other end connected to the operational drone 140. The tether is elevated and maintained in an obstacle-free suspended path through a plurality of support drones 135, 137, which are strategically positioned along the tether 130. The system of present invention avoids the common J-shaped curvature (similar to kite thread behavior) by employing fixed support drones 137 connected at non-insulated points (which are also known as power docks 160) and/or pass through loop support drone 135 along the tether. These power docks 160 allow the fixed support drones 137 to extract electrical power directly from the tether 130. The positions of the support drones 135, 137 and the tether management are regulated by an entanglement detection/prevention mechanism working along with the drone controller system and reeling/unreeling system 113 (spooling system), which dynamically adjusts drone positioning to maintain optimal tether 130 geometry and avoid obstacles, ground contact or entanglement. Furthermore, the tether drone system 100 also comprises vibration modules 155 for the anti-clogging mechanism in the application of payload material through the tether 130.
This figure showcases the dynamic tether elevation and entanglement-free routing, in combination with anti-clogging mechanism achieved via the cooperation of multiple supporting drones 135, 137, and multiple sensors fusion enhancing the real-time operational capability and safety of aerial agricultural tasks/missions.
Figure 3: Structure of Multi-channel Tether 130
Figure 3 depicts the construction of the multi-channel tether 130 comprising at least three channels:
Channel I (133): represents channel for continuous transmission of electrical energy from the base station 105 via power supply 107 to the operational 140 and support drones 135, 137.
Channel II (132): represents channel for continuous transmission of liquid conveying pesticides, fertilizers, or other fluid payloads via pump 115 from reservoir for liquid 109 located at the base station 105.
Channel III (131): represents channel for continuous transmission of solids such as seeds, granules, or powders, transported using a helical or screw-based propulsion mechanism similar to Archimedes screw mechanism via pump 117 from the reservoir for solid 111.

This figure reveals the integration of electrical, liquid, and solid delivery within a single flexible tether 130, allowing simultaneous multi-type payload application without the need for multiple systems or manual intervention.
Figure 4: Fixed Attachment of Support Drones with the tether
Figure 4 illustrates the configuration of fixed support drones 137 that are attached at predetermined non-insulated tether points (power docks) 160 and provide mechanical support and lift to the tether 130. Power dock 160 point also helps in extracting electrical power from the tether 130 for sustained operation of fixed support drones 137.
The fixed attachment is such that the drone 137 remains coupled to the same point unless explicitly detached during a repositioning operation (such as during reeling/unreeling operation and mechanism).

This embodiment enables the direct power delivery to aerial support drone 137 and offers stable lifting support, forming part of the novel and dynamic tether management system.
Figure 5: Pass-Through Loop Support Drone 135 with the tether 130
Figure 5 illustrates the pass-through loop support drone 135 as part of the tethered drone system 100 of the present invention. This type of support drone 135 is uniquely configured to mechanically support and guide the tether 130 (also inclusive of multichannel tether) without forming a fixed or electrically conductive attachment at any specific tether point.
The configuration of pass-through loop support drone 135:
• This type of support drone comprises a loop (135 b) or ring-like structure through which the tether freely passes, allowing bidirectional movement of the tether during reeling/unreeling operations and field navigation.
• The tether remains suspended in air, supported by the loop mechanism, without frictional clamping or obstruction.
• Unlike fixed support drones 137, this pass-through loop support drone 137 does not restrict tether displacement, thereby facilitating smoother real-time tether adjustment during operational drone movement or field navigation.
• Power supply to such a drone is achieved wirelessly via inductive charging. The support drone is embedded with inductive receiving coils in the loop (135 b), which harvest energy from the tether's electromagnetic field or an embedded inductive power line within the multichannel tether 130.
To maintain positioning and tether configuration, the pass-through loop drone 135 also comprises:
i. Assisted GPS (AGPS) and GPS modules for real-time location tracking,
ii. Inertial Navigation Systems (INS) with accelerometers and gyroscopes for flight stabilization and spatial awareness,
iii. Other sensors 150 including but not limited to obstacle detection sensors, environmental sensors, and sensors for drone-to-drone communication to monitor nearby terrain or drone proximity, along with the support drone telemetry.
These sensors allow the drone to autonomously hold altitude and position with respect to the other drones, compensating for wind, terrain changes, and dynamic tether tension, all without tether obstruction or entanglement.
Inventive Highlights:
• This drone acts as a non-intrusive tether lifting support, providing elevated suspension of tether and dynamic routing without introducing drag or resisting tether motion during the process of reeling/unreeling mechanism.
• The wireless inductive power system eliminates the need for onboard heavy batteries enabling extended flight time and lighter drone design.
• Sensor fusion (GPS/AGPS + INS + gyroscope) enables high-precision positional hold, making the drone stable and reliable even in variable field conditions or during rapid reeling/unreeling operations.
• It contributes to a scalable tether management system, allowing multiple such drones to be added or repositioned without interrupting tether flow or power.
Figure 6: Reeling/Unreeling system 113 at the base station 105
Figure 6 describes the mechanical reeling/unreeling system and operation which is regulated from the base station, comprising:
• A motorized reeling drum 113 with integrated tension and spool sensors;
• Bidirectional tether control to extend or retract the tether 130,
• Coordinated drone repositioning, wherein:
o Fixed support drones 137 shift positions during changes in tether 130 length,
o The nearest drone to the operational drone detaches and repositions as required,
o Pass through loop-type 135 drones facilitate smooth tether motion.
Figure 7 illustrates the real-time control for the reeling and unreeling operation and mechanism, drone repositioning mechanism.
? The mechanism of Reeling/Unreeling operation comprises:
1. Initiation of Mission / Operation Start
i. The controller at base station 105 initializes the operation and determines the target coverage zone based on pre-determined coordinates or real-time scouting/surveillance (e.g., minion surveillance drone 145 data).
ii. A default tether length is set for launch.
2. Positional Data Collection from Operational Drone
i. The operational drone 140 continuously transmits:
o GPS coordinates
o Altitude and flight direction
ii. Optionally enhanced by sensors 150 including but not limited to INS (Inertial Navigation System) and gyroscope, for refined movement tracking.
3. Tether Geometry Monitoring via Support Drones
i. Support drones (fixed 137 or pass through loop type 135) detect:
o Curvature of the tether 130 in their local vicinity
o Possible slack, tension anomalies, or collision/entanglement risks
ii. These drones 135, 137, 140 send telemetry to the drone system controller at the base station 105.
Telemetry in the present invention refers to but not limited to the automated communication process by which measurements and data from a remote device (such as the support drones 135, 137, minion surveillance drone 145 ) are collected and transmitted to a central system (such as drone system controller at the base station 105).
Functional importance of telemetry in present invention:
Support drone telemetry is crucial for:
i) Maintaining correct tether curvature
ii) Avoiding tether entanglement
iii) Optimizing reeling/unreeling coordination
iv) Triggering repositioning of fixed/loop drones
v) Integrating with anti-clogging and obstacle avoidance systems
4. Mechanical Feedback from Spooling System 113 (reeling/unreeling system at the base station)
i. Tension sensors on the reel detect:
a. Sudden load increases (signaling drag or entanglement risk);
b. Load drop (indicating slack or operational drone descent)
ii. Spool sensors detect tether length deployed/retrieved in real time.
5. Decision-Making by Drone System Controller at the base station 105
i) The drone controller system at base station 105 receives and integrates data from:
o Operational drone 140 (including but not limited to position, motion, spray pattern status)
o Supporting drones 135, 137(including but not limited to local tether geometry, power status of the untethered drone)
o Spooling sensors 113 (tension/load, unreel/reel length)
ii) A feedback mechanism evaluates whether to:
o Extend tether (unreel)
o Retract tether (reel)
o Maintain current length
6. Execution of Spooling Action
• Based on the decision mentioned above, the motorized reel drum is activated to:
o Reel in or unreel the tether
7. Adjustment of Support Drone
• As the tether length changes:
o Fixed support drones 137 detach and reposition forward or backward along the tether 130 (as required)
o Pass-through loop drones 135 remain stationary, allowing smooth tether motion, as well as maintaining the appropriate tether lift and tether configuration.
8. Real-Time Recalibration and Continuity
• The entire process runs continuously and dynamically, adjusting to:
o Operational drone 140 changes in path or spray zones
o Terrain irregularities
o Obstacle avoidance instructions from the entanglement prevention system.
Flowchart in figure 7 depicts:
The flowchart illustrated in Fig. 7 represents the real-time control system for the reeling and unreeling mechanism of the tethered drone system 100. The drone system controller is configured to continuously integrate and process data from multiple sources, including: positional inputs from the operational drone 140 (utilizing fused sensor data such as GPS, Assisted GPS (AGPS), and Inertial Navigation Systems (INS)); telemetry feedback from support drones 135, 137; tether tension/load metrics and spool status from base station sensors; and obstacle detection inputs from the entanglement detection and prevention mechanism.Figure 8: Entanglement Detection and Prevention System
Figure 8 illustrates the entanglement detection and prevention system of the present invention, which ensures safe, uninterrupted operation of the tethered drone system by dynamically managing the spatial arrangement and flight paths of both operational 140 and support drones 135, 137 in real-time.
The red and blue directional arrows illustrated adjacent to the support drone in Figure 8 represent the multidirectional maneuverability of the support drones, which is employed to actively prevent entanglement and/or crossover of the tether during operation. These directional adjustments are part of the real-time tether management strategy, as described in detail below, and enable dynamic repositioning of the support drones to maintain optimal tether alignment and clearance from obstacles or other drones.
The entanglement detection and prevention system and mechanism comprising:
i) Positional and motion sensors 150 integrated into both operational drones 140 and support drones 135, 137, including:
o Global Positioning System (GPS) sensors,
o Assisted GPS (AGPS) modules utilizing cellular signal triangulation,
o Inertial Navigation System (INS) incorporating accelerometers,
o Gyroscopes for detecting angular velocity,
ii) A drone system controller housed in the base station 105, which continuously receives telemetry from the drones 135, 137, 140,
iii) Real-time trajectory analysis mechanism that predict potential tether 130 crossover or conflict zones based on drone velocity vectors, path curvature, and field boundaries.
The operational drone 140 continuously communicates its positional vector and flight trajectory to the drone system controller. Simultaneously, support drones 135, 137 relay their own telemetry (for instance but not limited to position, altitude, angular orientation) to the drone system controller. By comparing this data, the drone system controller:
i) Detects potential entanglement risk events, such as when the operational drone 140 is projected to pass near or across a fixed or loop support drone;
ii) Calculates appropriate corrective actions, such as adjusting the position of support drones 135,1 37 to prevent tether intersections/crossovers;
iii) Issues commands to reposition support drones 135, 137 either vertically, horizontally, or rotationally, depending on the situation and tether curvature;
iv) Maintains appropriate tether geometry/configuration and spacing between drones 135,137, 140, even as the operational drone 140 moves across complex terrain or variable crop densities.
Inventive Highlights:
i) The entanglement detection and prevention system and mechanism form a geo-aware, self-regulating tether routing mechanism that operates autonomously, without the need for manual ground-based intervention.
ii) By leveraging fusion of multiple sensors 150(for instance but not limited to GPS + AGPS + INS + gyroscope), the entanglement detection mechanism ensures (very high level precision up to a scale of millimeter-level precision) in predicting and preventing tether, drone collision risks.
iii) The system is scalable and adapts to both large-area coverage and irregular field topographies, thus enabling uninterrupted multi-drone coordination over extended time durations and operational ranges.
iv) Integrating this system with the support drone’s mobility (in both fixed and pass-through loop configurations) enables real-time tether reconfiguration, reducing downtime and improving aerial system reliability.
• Reducing downtime in the present invention refers to avoiding interruptions caused by (including but not limited to):
o Tether entanglement
o Manual repositioning of support drones
o clogging in the tether
o multiple battery swaps
• Maintaining continuous payload delivery (e.g., liquids, granules, seeds, different liquid fertilizer, pesticides, foams, etc) without requiring frequent halts for adjustments
• Maximizing operational efficiency across large agricultural fields without pausing the drone operation due to mechanical reconfiguration or system errors.
Advantages introduced by reduced downtime, in the present invention include but are not limited to:
1. Higher field coverage per flight;
2. Increased productivity in agricultural applications;
3. Less manual labor or technician intervention;
4. Improved system reliability.
Figure 9: Operational Drone 140 and its components
The operational drone 140 of the present invention functions as the primary applicator unit within a tethered drone system 100 designed for agricultural operations. Powered and supplied via a multichannel tether 130 from a base station 105, it supports uninterrupted, multi-type payload delivery without the limitations of onboard energy or material storage.
Key Components and Features:
• Frame and Propulsion:
Lightweight carbon fiber-reinforced polymer (CFRP) frame; for high lift, stability, and maneuverability.
• Multifunctional Nozzle System 143 :
A universal/unified/common outlet dispensing different payload materials including but not limited to liquids, granules, powders, seeds, foams, and gases; features adaptive geometry, sensor-controlled spray modes, and clog-detection mechanisms.
• Advanced Sensor 150 Suite:
GNSS (GPS+RTK/PPK), IMU/INS, gyroscope, ultrasonic, LiDAR, and optical sensors for micro-positioning, terrain adaptation, and obstacle detection.
• Payload Interface:
Integrated inlet manifolds for liquid and solid material intake from tether 130; includes embedded flow regulators for precise discharge control.
• Communication and Control:
Wireless modules for telemetry with support drones 135, 137 and base station 105; along with real-time adjustment based on environmental inputs.
• Tether Interface:
Mechanically/electrically coupled to multichannel tether for continuous power and payload supply.
Advantages of operational drone Over Prior Art:
i. Continuous Power and Payload Supply via tether 130—eliminates downtime.
ii. Simultaneous Multi-Material Delivery with no need for refills or manual switching.
iii. Real-Time Autonomous Navigation and adaptive terrain-following using multi-sensor 150 input.
iv. Integrated Anti-Clogging System ensures consistent flow of viscous or granular payloads.
v. Coordinated Operation with support drones 135, 137 and reeling systems 113for tether management and entanglement avoidance.
The present invention is further disclosed by way of the embodiments which can be separately or jointly implemented and are not intended to limit the scope of the invention, but to illustrate potential applications and implementations in alignment with the novel and inventive concept of the present invention.
In one of the embodiments, present invention provides operational drone 140 for Spraying (liquids pesticides, fertilizers, etc.), Broadcasting drone (for solids like granules, seeds, etc.), and Subsurface applicator drone (for injections of seeds below canopy or soil level), or combinations thereof.
In one of the embodiments, present invention provides tethered drone system 100 with multi-type payload delivery.
In one of the embodiments, a tethered drone system 100 of the present invention comprises an operational drone 140 configured for aerial application of different types of payloads over agricultural fields simultaneously.
In one of the embodiments, present invention provides a multichannel tether 130 comprising dedicated channels for continuous transmission of electric power, different types of payloads including but not limited to liquids, solids (such as seeds or granules), foams, and gases or combinations thereof.
In one of the embodiments, present invention provides a base station 105 connected to one end of the tether, configured but not limited to components or systems such as pumps (115, 117), power supply 107 unit(s), and reeling/unreeling system (spooling system) 113, or mechanisms, drone controller system etc.
In one of the embodiments, present invention provides the tethered drone system 100 which enables uninterrupted and simultaneous delivery of multiple types of payloads without replacing or changing the tether.
In one of the embodiments, present invention provides continuous power supply through Tethered configuration.
In one of the embodiments, present invention provides a tethered drone system 100 wherein the operational drone 140 and multiple support drones 135, 137 are continuously powered through electric cables embedded in the tether (or multichannel tether)130.
In one of the embodiments, present invention provides a tethered drone system 100 wherein the support drones 135, 137 with fixed attachment 137 derive power through contact points (power docks) 160.
In one of the embodiments, present invention provides a tethered drone system wherein the pass-through loop drones 135 utilize inductive power transfer mechanisms using inductive coils in-built in the loop (135 b) in order to derive power from the tether 130 and operate without fixed tether contact.
In one of the embodiments, present invention provides dynamic tether management using support drones 135, 137, base station 105, operational drone 140, and sensors 150 embedded in the drones of present invention.
In one of the embodiments, present invention provides a tethered drone system 100 comprising a plurality of support drones, wherein each drone is operatively coupled to the tether via a fixed attachment or pass-through loop mechanism.
In one of the embodiments, present invention provides a tethered drone system 100 wherein a tether management system enables real-time adjustment of the tether’s three-dimensional path using the aerial positions of the support drones (135, 137).
In one of the embodiments, present invention provides a tethered drone system 100 wherein an entanglement detection and prevention mechanism using sensors 150 and modules including but not limited to GPS, gyroscopes, ultrasonic sensors, and drone-to-drone communication to prevent tether drag, slack, or entanglement during operation.
In one of the embodiments, present invention provides a tethered drone system which comprises sensor fusion (coordinated working of different sensors disclosed in the present invention) including but not limited to (GPS/AGPS + INS + gyroscope) which enables high-precision positional hold, making the drones (operational 140 and support drone 135, 137) stable and reliable even in variable field conditions or during rapid reeling/unreeling operations.
In one of the embodiments, the sensor fusion of the present invention provides scalable tether management system, allowing multiple drones to be added or repositioned without interrupting tether flow or power, curvature, geometry/configuration.
In one of the embodiments, present invention provides an anti-clogging and sensor-Based payload control.
In one of the embodiments, present invention provides a tethered drone system, wherein the tether includes embedded flow sensors and pressure sensors for real-time monitoring of payload delivery.
In one of the embodiments, present invention provides a tethered drone system which comprises anti-clogging mechanisms, including but not limited to piezoelectric actuators or vibration motors (such as vibration elements/modules)155, are activated automatically upon detection of flow obstruction;
In one of the embodiments, the inner surface of the tether and nozzle system comprises a non-stick material to reduce residue accumulation.
In one of the embodiments, present invention provides a tethered drone system which comprises multifunctional nozzle system 143.
In one of the embodiments, present invention provides a tethered drone system 100 which comprises a multifunctional nozzle 143 mounted on the operational drone 140 capable of dispensing various payload types including but not limited to (granules, liquids, foams, solids, seeds, gases, powders).
In one of the embodiments, present invention provides a tethered drone system which comprises an adaptive nozzle controller configured to automatically adjust spray pattern, nozzle geometry, and particle output parameters based on the payload characteristics detected by sensors.
In one of the embodiments, present invention provides a tethered drone system 100 which comprises sensor feedback including but not limited to blockage detectors, particle recognition systems, and flow rate sensors.
In one of the embodiments, present invention provides a tethered drone system which comprises pass-through loop drones with wireless power transfer using shielded inductive coils in the tether or in the loop of the support drone.
In one of the embodiments, present invention provides a tethered drone system, wherein:
i. one or more support drones are connected via a pass-through loop mechanism allowing tether to slide freely;
ii. such drones are powered by wireless inductive power received through a shielded Electromagnetic coil embedded in the drone;
iii. the coil is shielded using materials selected from ferrite composites, mu-metal, nickel alloys, or conductive polymers to prevent electromagnetic interference.
In one of the embodiments, present invention provides a tethered drone system which comprises reeling/unreeling operation and mechanism, and Tether Length Control.
In one of the embodiments, present invention provides a tethered drone system 100 comprising:
i. a base station 105 with reeling/unreeling system controlled via a motorized drum 113, drone controller system, support drones 135, 137, operational drone 140, telemetry data/signal from drones, obstacle/entanglement detection and prevention mechanism;
ii. sensors for spooling and tension sensing;
iii. automatic reeling or unreeling triggered by positional feedback from the operational drone 140 and support drones (135, 137) to maintain optimal/required tether length and reduce slack or overextension.
In one of the embodiments, present invention provides a tethered drone system which comprises integration of minion surveillance drones for soil analytics.
In one of the embodiments, present invention provides a tethered drone system, wherein:
i. one or more untethered minion surveillance drones 145 are configured to collect field data including but not limited to pest presence, crop health, and soil nutrient levels;
ii. the data is transmitted to the base station to enable customized payload delivery and drone movement based on real-time environmental parameters.
In one of the embodiments, present invention provides a tethered drone system 100 which comprises terrain-adaptive tether geometry and micro-positioning.
In one of the embodiments, present invention provides a tethered drone system 100 which comprises:
i. Global Navigation Satellite System (GNSS)-enabled drones with Real-Time Kinematic (RTK)-based correction modules enabling centimeter-level positioning of operational and support drones;
ii. a real-time terrain mapping module integrating laser sensors including but not limited to LiDAR, other sensors including but not limited to ultrasonic, and optical sensors to adapt tether elevation and curvature over uneven or obstacle-rich terrain;
In one of the embodiments, present invention provides a tethered drone system 100 which comprises micro-positioning which enable safe tether paths, effective payload targeting, and precision farming applications.
In one of the embodiments, present invention provides a tethered drone system which comprises obstacle avoidance and entanglement prevention system.
In one of the embodiments, present invention provides a tethered drone system which comprises:
i. a geo-aware obstacle avoidance system integrated with drone trajectory mapping and spatial tether control;
ii. drone positioning based on fusion of multiple sensors including but not limited to GNSS, gyroscope, accelerometer, and ultrasonic sensors;
iii. drone controller system/mechanism that detects risk of entanglement, performs predictive adjustments, and repositions support drones dynamically to maintain safe tether geometry.
In one of the embodiments, present invention provides a tethered drone system which comprises dual attachment configuration for support drones to facilitate the dynamic tether management.
In one of the embodiments, present invention provides a tethered drone system which comprises:
i. a hybrid combination of fixed-attachment drones 137 and pass-through loop drones 135;
ii. the fixed drones 137 provide both mechanical support and power reception at predetermined intervals;
iii. the pass-through drones 135 provide drag-free and smooth tether guidance and enable unrestricted tether movement during reeling/unreeling operations.
In one of the embodiments, present invention provides a tethered drone system which comprises field-adaptive payload mixing and delivery system.
In one of the embodiments, present invention provides a tethered drone system which comprises:
i. integrated supply tanks with automated mixing modules at the base station;
ii. soil sensors or data obtained from surveillance minion drones 145 guiding the customized composition of fertilizers, pesticides, or other agricultural solutions;
iii. real-time modification of payload mix based on target/desired field segment-specific parameters.
In some embodiments, the present invention provides the inner surface of the nozzle and/or the channels of the tether may be coated or lined with a non-stick material.

In some embodiments, the non-stick material is selected from the group comprising material including but not limited to Polytetrafluoroethylene (PTFE), Perfluoroalkoxy Alkane (PFA), Ultra-High Molecular Weight Polyethylene (UHMWPE) or silicone elastomer, or superhydrophobic coating, etc., to prevent clogging, residue buildup, or material adherence during the delivery/operations of handling various payload types using tether and/or nozzle.”
In one of the embodiments, the examples of relevant non-stick materials comprises, but are not limited to:
1. Polytetrafluoroethylene PTFE (Teflon): Chemically inert, highly non-stick, and heat resistant.
2. Perfluoroalkoxy Alkane (PFA): Flexible, transparent fluoropolymer with similar non-stick and chemical resistance as PTFE.
3. Silicone Elastomer: Flexible, non-stick material, suitable for liquids and foams.
4. Ultra-High Molecular Weight Polyethylene (UHMWPE): Low-friction, abrasion-resistant plastic for solids and granules.
5. Superhydrophobic Coating (e.g., nano-silica): Ultra water-repellent for critical nozzle surfaces.
6. Ethylene Tetrafluoroethylene (ETFE): UV-resistant material, durable fluoropolymer ideal for outdoor tether coating. Provides prolonged tether life
Advantages of using such material in the present invention:
a) reduces clogging; and
b) reduce/minimizes residue buildup,
c) resists chemical corrosion,
d) enables smooth multi-type payload flow, and
e) extends the operational lifespan of both the tether and nozzle under diverse environmental and payload conditions.
In an embodiment, the tethered drone system 100 incorporates spatial positioning technologies including but not limited to GPS, Assisted-GPS (AGPS), and Inertial Navigation Systems (INS) comprising gyroscopes and accelerometers, which may be optionally enhanced via Global Navigation Satellite System (GNSS) platforms.
To enable centimeter-level accuracy in drone positioning and tether alignment, the system optionally integrates Real-Time Kinematic (RTK) correction modules or Post-Processed Kinematic (PPK) processing workflows. These enhancements are particularly beneficial for applications requiring micro-positioning, such as tether geometry control, drone-to-drone alignment, and path repeatability in agricultural plots.
In accordance with one or more embodiments of the present invention, a tethered drone system with integrated sensors is disclosed, comprising an operational drone, multiple support drones (both fixed-attachment and pass-through loop configurations), minion surveillance drones, and a dynamic tether management system. This system is designed to ensure uninterrupted power delivery, payload dispensing (liquid, solid, seeds, granules, foams, etc.), and real-time obstacle avoidance and entanglement prevention through a comprehensive network of multiple-sensors including fusion of working of multiple sensors for adaptive control and management of the tethered drone system.
Below-mentioned are the sensors utilized in the present invention, which comprises but is not limited to the following:
1. Multi-Sensor Cooperative Obstacle Avoidance System
Each drone of the tethered drone system of present invention may be equipped with sensors 150 including but not limited to:
i. Optical sensors (for instance but not limited to stereo cameras, depth sensors),
ii. Laser range sensors (e.g., LiDAR) for terrain and object mapping,
iii. Ultrasonic proximity sensors for short-range detection,
iv. Gyroscopic stabilizers for angular control and stabilization.
These sensors 150 are highly useful as they enable the drones to:
i. Detect obstacles such as trees, poles, uneven terrain, and other near-by drones;
ii. Autonomously reconfigure their flight paths;
iii. Maintain optimal separation between tether and surrounding obstructions;
iv. Prevent crossover entanglement events in the aerial corridor of operation.
This sensor-based spatial awareness across all drone types facilitates intelligent, autonomous navigation during active fieldwork.
2. Dynamic Tether Management driven by sensors 150
The present invention incorporates a dynamic tether management mechanism which may further comprise sensors, wherein:
i. Global Navigation Satellite Systems (GNSS), comprising one or more of GPS, GLONASS, Galileo, and BeiDou, etc, are embedded in both operational and support drones for accurate positional tracking.
ii. Real-Time Kinematic (RTK) or Post-Processed Kinematic (PPK) correction techniques are used to enable micro-positioning with centimeter-level accuracy.
iii. Gyroscopes, accelerometers, and Inertial Navigation Systems (INS) provide real-time feedback for pitch, yaw, roll, and translational motion.
iv. Sensor fusion module integrates inputs from all sensors to maintain tether geometry in 3D space, adapting to the operational drone's flight trajectory and field topography.
This real-time coordinated control ensures that the tether remains suspended, tension-regulated, and free from entanglement or terrain interference.
3. Real-Time Entanglement Detection and Prevention
The entanglement prevention subsystem comprises:
• Real-time GPS/AGPS-based location updates from all aerial units;
• Ultrasonic and optical sensors to detect approaching tether or drone trajectories;
• A centralized drone system controller that runs predictive mechanism to forecast potential tether entanglement;
• Autonomous drone-to-drone communication protocols for real-time adjustment in drone positioning to avoid tether crossover events.
This system allows proactive, rather than reactive, tether routing and stabilization—a significant improvement over passive or manual systems of tethered or untethered drone.
4. Sensor-Based Tether Adaptation in Varying Terrain
As the operational drone navigates agricultural plots, the tether adapts its vertical and horizontal geometry by:
• Analyzing terrain elevation using laser sensors (including but not limited to LiDAR) and optical depth sensing;
• Receiving altitude correction feedback from ultrasonic sensors;
• Using gyroscopic and Inertial Measurement Unit (IMU, i.e., a component of INS system)-based feedback for drift compensation;
• Adjusting support drone positioning (via power-dock relocation or loop maneuvering) to maintain ideal tether alignment.
This results in a smart, adaptable tether profile that allows uninterrupted, obstacle-free movement across diverse field terrains.
5. Inductive Pass-Through Loop Support Drone 135 Control
In one embodiment, the pass-through loop support drones are wirelessly powered via inductive charging coils embedded/in-built within drone (in loop) or aligned with the tether.
This pass-through loop support drone configuration enables uninterrupted reeling/unreeling operations, improved tether maneuverability, and seamless tether length adjustments.
6. Micro-Positioning Using GNSS and IMU Fusion
In a preferred embodiment, micro-positioning of each aerial unit is achieved using:
i. GNSS + RTK modules on each drone;
ii. A drone controller system at the base station for correction data;
iii. Integration of IMUs (gyroscopes, accelerometers) for improved spatial awareness and continuity in GPS-degraded zones (e.g., under canopy or cloudy environments).
This spatial precision supports:
a) Coordinated reeling/unreeling operations;
b) Predictive entanglement avoidance;
c) Precision payload targeting (e.g., seed rows, spray paths);
d) Repeatable flight paths for multi-session operations.
Inventive step & technical advancement related to the integrated sensors in the tethered drone system
The inventive aspect lies not merely in the use of sensors, but in their cooperative, autonomous, and real-time integration across a multi-drone system to manage a physical multichannel tether in 3D space. The system supports:
a) Simultaneous delivery of multi-form payloads,
b) Wireless drone power transmission via inductive coupling,
c) Self-regulating tether suspension and routing,
d) Uninterrupted, large-scale agricultural operations, and
e) Precision drone control in dynamically changing field environments.
This level of sensor-driven coordination and tether adaptability is not disclosed in or suggested by any known tethered drone systems and represents a significant technical improvement over conventional solution.
The above-mentioned sensors are cooperatively integrated across multiple aerial units (i.e., operational 140 , support 135, 137, minion surveillance drone 145) to dynamically and autonomously manage the geometry/configuration of a multichannel tether in real-time, allowing for uninterrupted, obstacle-free, and extended-duration agricultural operations—a solution not achievable by existing tethered or untethered systems.
In an embodiment of the present invention, the tethered drone system 100 incorporates spatial positioning technologies including but not limited to GPS, Assisted-GPS (AGPS), and Inertial Navigation Systems (INS) comprising gyroscopes and accelerometers, which may be optionally enhanced via Global Navigation Satellite System (GNSS) platforms.
In an embodiment of the present invention, to enable centimeter-level accuracy in drone positioning and tether alignment, the tethered drone system optionally integrates Real-Time Kinematic (RTK) correction modules or Post-Processed Kinematic (PPK) processing workflows. These enhancements are particularly beneficial for applications requiring micro-positioning, such as tether geometry control, drone-to-drone alignment, and path repeatability in agricultural plots.
In one of the embodiments, the present invention discloses the advantages of the GNSS, RTK, and PPK in the Tethered Drone System, which includes but are not limited to:
i. High-Precision Positioning using Real-Time Kinematic/ Post-Processed Kinematic (RTK/PPK)- Enables precise support drone placement to dynamically manage tether sag, tension, and curvature.
ii. Real-Time Corrections using Real-Time Kinematic (RTK)- Allows instant drone repositioning to prevent tether entanglement and maintain optimal geometry during reeling/unreeling operations.
iii. Post-Mission Accuracy using Post-Processed Kinematic (PPK)- Enables high-fidelity mapping and analytics for field replay, ensuring accurate repeatable deployment across sessions.
iv. GNSS Flexibility- Multi-constellation support (GPS, GLONASS, Galileo, BeiDou) allows stable performance in rural/agricultural regions with varying signal strength.
v. Micro-Positioning- Crucial for multi-drone cooperative flight, tether cross-section control, and navigation near terrain obstacles
In an embodiment, the spatial positioning framework of the tethered drone system utilizes GPS/AGPS-based navigation, integrated with an Inertial Navigation System (INS) comprising gyroscopes and accelerometers.
In more advanced configurations, the system further includes GNSS-based modules enhanced with Real-Time Kinematic (RTK) correction for real-time positional updates with centimeter-level accuracy, and/or Post-Processed Kinematic (PPK) modules for post-mission precision validation. These features collectively support drone-to-drone spatial synchronization, real-time tether curvature control, and precision guidance of the operational drone, particularly within complex or obstacle-rich agricultural environments.
In one of the embodiments, the Operational Drone of the tethered drone system is made up of material including but not limited to Carbon fiber-reinforced polymer (CFRP), Polycarbonate composite, metal alloys (such as Magnesium alloys for selective internal structural elements).
These materials provide the following characteristic to the operational drone of present invention, including but not limited to:
i. High strength-to-weight ratio
ii. Corrosion-resistant (against fertilizers/pesticides)
iii. Lightweight to extend flight time
iv. UV-resistant for outdoor exposure
In one of the embodiments, the operational drone may be constructed using carbon fiber-reinforced polymer or polycarbonate composites to provide a lightweight, durable, and chemically resistant aerial platform capable of withstanding prolonged exposure to agricultural chemicals and UV radiation, while supporting extended airborne payload delivery.
In one of the embodiments, wherein the reinforced polymer in the Carbon fiber-reinforced polymer (CFRP), may be selected from the group comprising polymer matrix.
In one of the embodiments, wherein the comprising polymer matrix may be selected from the group comprising of Epoxy resin, Polyester resin, Polyether Ether Ketone (PEEK), or Polyamide (Nylon) or combinations thereof.

In one of the embodiments, the Support Drones (Fixed and Pass-through Loop Types) are made up of material including but not limited to Carbon fiber-reinforced polymer (CFRP) for frame and body, Acrylonitrile Butadiene Styrene (ABS) or polyamide (Nylon) for outer casing, Shielded electromagnetic (EM) coil (for pass through loop support drones in view of inductive charging).
These materials provide the following characteristic to the support drone of present invention, including but not limited to:
i) CFRP: Strong, light, vibration-dampening structure
ii) ABS/Nylon: Tough, shock-resistant, low-cost
iii) Shielded EM coil: Compatible with inductive power transfer.
In one of the embodiments, Support drones may be constructed using carbon fiber-reinforced polymer for their structural frame and polyamide or ABS polymer for their outer casing, offering mechanical strength and environmental durability. Loop-type drones 135 may include inductive coils made from magnetically shielded copper or ferrite-core windings for efficient wireless charging via electromagnetic induction.
In one embodiment, the pass-through loop support drone comprises an inductive power receiving module inbuilt in the loop (135 b) that includes a shielded electromagnetic (EM) coil. The shielding is configured to minimize electromagnetic interference and maximize power transfer efficiency during tethered operations.
The shielding of the EM coil comprises of materials including but not limited to ferrite sheets or mu-metal, optionally coated with polymer insulation to prevent corrosion and environmental degradation.
In one of the embodiments, the shielding of EM coil is done by using Ferrite sheet core for magnetic shielding and/or copper or aluminium outer shell which provides lightweight casing with protective polymer insulation.
In one of the embodiments, the operational 140 and supporting drones 135, 137 may be constructed using a carbon fiber-reinforced polymer composite, wherein high-strength carbon fibers are embedded in an epoxy-based polymer matrix. This provides an optimal combination of structural rigidity, lightweight performance, and resistance to mechanical fatigue, making it suitable for long-duration aerial operations under varying environmental conditions.
In one of the embodiments, tether (such as Multichannel Tether) can be made up of materials, including but not limited to:
i. Outer sheath: UV-stabilized ETFE (ethylene tetrafluoroethylene) or TPU (thermoplastic polyurethane);
ii. Power cable insulation: by using material such as Polytetrafluoroethylene (PTFE) or Cross-Linked Polyethylene (XLPE);
iii. Liquid/solid conduit lining: by using material such as Polytetrafluoroethylene (PTFE) or Ultra-High Molecular Weight Polyethylene (UHMWPE)
iv. Optional Reinforcement layer: Braided aramid fibers (e.g., for instance like Kevlar)
These materials provide the following characteristic to the tether of present invention, including but not limited to:
i. Non-stick, chemical-resistant interiors (PTFE/UHMWPE) prevent clogging
ii. ETFE outer sheath resists UV, abrasion, and weather
iii. Aramid fibers reduce tether sag and improve tensile load capacity
In one of the embodiments of the present invention, the multichannel tether may comprise an outer sheath formed from UV-stabilized ETFE or thermoplastic polyurethane for abrasion and environmental protection. The internal channels are lined with PTFE or UHMWPE to minimize residue buildup and prevent clogging from liquid or solid payloads. Reinforcement using aramid fibers provides high tensile strength and flexibility, reducing sag and tether drag during deployment.
In one of the embodiments, the Multifunctional Spray Nozzle 143 can be made up of materials, including but not limited to:
i. Nozzle body: Stainless steel or high-grade PEEK (polyether ether ketone)
ii. Coating: Polytetrafluoroethylene (PTFE) or ceramic composite
iii. Internal seals/gaskets: Ethylene Propylene Diene Monomer (EPDM)
iv. Sensor housing: Polycarbonate or anodized aluminium.
These materials provide the following characteristic to the multifunctional spray nozzle of present invention, including but not limited to:
i. Polyether ether ketone (PEEK)/Stainless steel: Chemical and pressure resistance;
ii. Polytetrafluoroethylene (PTFE) coating: Anti-clogging
iii. Ethylene Propylene Diene Monomer (EPDM): Resilient to chemical degradation
iv. High-temperature and abrasion resistance
In one of the embodiments, the present invention provides the multifunctional spray nozzle which may be constructed from chemically resistant materials such as stainless steel (316L) or PEEK polymer, with internal surfaces coated in PTFE to minimize clogging from various payload types. Internal gaskets and seals may be formed from EPDM or Viton to maintain pressure integrity and compatibility with fertilizers, pesticides, and foam agents.
In one of the embodiments, the Locking Mechanism (for Fixed Attachment of Support Drones) can be made up of material including but not limited to:
i. Lock body: Anodized aluminium or stainless steel
ii. Latch spring: Phosphor bronze or stainless spring steel
iii. Grip pads or contact liners: Thermoplastic polyurethane (TPU) or silicone rubber (non-slip, vibration absorbing)
iv. Insulated electrical contact (power dock): Gold-plated copper alloy
These materials provide the following characteristic to the Locking Mechanism of present invention, including but not limited to:
i. Durable and corrosion-resistant lock body
ii. Spring mechanism for secure engagement/release
iii. Gold-plated contact for reliable power conduction at tether connection
In one of the embodiments, the lock may be selected from the electromagnetic or mechanical lock, or combinations thereof.
In one of the embodiments, the fixed locking mechanism for support drones may be formed from anodized aluminium or stainless steel to provide high structural stability and corrosion resistance. Contact points at the power dock may include gold-plated copper alloy terminals to ensure efficient electrical transfer with minimal oxidation. Grip liners made from silicone or thermoplastic polyurethane (TPU) may be included to dampen vibrations and enhance tether hold stability.
In one of the embodiments, the present invention provides an anti-clogging mechanism for the smooth and efficient transport of the payload components.
In one of the embodiments, the anti-clogging mechanism comprises localized vibrations through small embedded vibration modules 155.
In one of the embodiments, the vibration module may be selected from the group comprising piezoelectric actuators or mini eccentric motors or combinations thereof, attached on the tether at a specific point.
In one of the embodiments, the vibration module may be selected from the group comprising piezoelectric actuators or mini eccentric motors or combinations thereof, attached to the support drone 135, 137 which provides suitable vibration for dislodging the clogged material or for smooth and efficient transfer of the payload material through the tether.
In one of the embodiments, the vibration module may provide trigger periodic mechanical agitation of the tether during material delivery.
In one of the embodiments, the vibration module is controlled via signal from the Drone System Controller located at the base station.
In one of the embodiments, the drone system controller can provide signal by analysing and monitor payload flow rates or pressure drops (via suitable sensors) which may automatically trigger vibration cycles or purge actions when flow blockage is detected or predicted. Such a trigger may lead to activation of vibration module for its anti-clogging functions in real time, located on the tether and/or on the support drone.
In one of the embodiments, the present invention comprises:
i. Nozzle geometry suitable for all material types
ii. Automatic identification of input material and corresponding pattern control
iii. Safety lockout systems
iv. Remotely controllable switching valves
v. Real-time telemetry feedback from nozzle sensors to the drone system
In some embodiments, the tethered drone system further comprises advanced sensor subsystems to enhance positional accuracy, movement prediction, and real-time tether management.
In some embodiments, wherein the tethered drone system comprises inertial navigation system (INS) incorporating one or more accelerometers to measure linear acceleration, enabling real-time estimation of drone movement and orientation relative to the tether;
In some embodiments, wherein the tethered drone system comprises an assisted GPS (AGPS) module configured to enhance positional accuracy using cellular signal triangulation, particularly useful in low-satellite visibility regions such as forest boundaries or remote agricultural fields;
In some embodiments, wherein the tethered drone system comprises a gyroscope to detect angular velocity and rotational motion of the drones, which in combination with INS and GPS data, supports dynamic adjustment of tether curvature and drone alignment.
In some embodiments, wherein the tethered drone system comprises these sensor systems collectively feed into the entanglement detection and prevention module of the tethered drone system. They enable precise localization, movement tracking, and predictive modeling to maintain safe aerial operations, avoid obstacles, and dynamically adjust the position of support drones.
In an embodiment, the entanglement detection and prevention system, comprises:
i) Positional and motion sensors integrated into both operational drones and support drones, including:
a) Global Positioning System (GPS) sensors,
b) Assisted GPS (AGPS) modules utilizing cellular signal triangulation,
c) Inertial Navigation System (INS) incorporating accelerometers,
d) Gyroscopes for detecting angular velocity,
ii) A drone system controller housed in the base station 105, which continuously receives telemetry from the drones,
iii) Real-time trajectory analysis mechanism that predict potential tether crossover or conflict zones based on drone velocity vectors, path curvature, and field boundaries.
In one of the embodiments, the support drones are configured to transmit telemetry data comprising positional coordinates, altitude, orientation parameters, and optionally tether load or vibration data to the drone system controller. This telemetry allows the system to dynamically manage tether geometry, regulate support drone spacing, and assist in the reeling/unreeling operations in real-time.
In one of the embodiments, present invention provides a tethered drone system comprising a multichannel tether 130 extending between a base station 105 and an operational drone 140 , wherein the multichannel tether 130 is configured to simultaneously transmit electric power and deliver multiple agricultural payloads including but not limited to liquids, solids, seeds, foams, and gases, etc or combinations thereof.
In one of the embodiments, present invention provides the multichannel tether 130, which comprises dedicated channels for power, liquids (lined with corrosion-resistant material and non-stick material), and solids (configured with helical or screw-based propulsion mechanism similar to Archimedes screw mechanism).
In one of the embodiments, the tether of any or all of the channels includes a non-stick inner surface layer to reduce clogging caused by residue or particulate matter.
In one of the embodiments, present invention provides a tethered drone system comprising a plurality of support drones for tether lifting, suspension, and management wherein at least one support drone is fixedly attached to the tether at a designated position on tether i.e., power dock 160.
In one of the embodiments, present invention provides a tethered drone system comprising a plurality of pass-through loop support drones, wherein the tether passes through a loop interface of the drone without mechanical fixation, allowing dynamic tether movement during reeling/unreeling operation and mechanism.
In one of the embodiments, the pass-through loop support drones of present invention are configured to receive power wirelessly from the tether using inductive charging modules (coils) inbuilt in the loop (135 b) shielded with suitable materials selected from but not limited to ferrite composites, copper mesh, or carbon-loaded polymers.
In one of the embodiments, present invention provides an operational drone operatively coupled to the multichannel tether 130, wherein the operational drone 140 comprises a multifunctional spray nozzle 143 capable of dispensing various payload types (including but not limited to solid, liquid, granules, foams) from a common outlet.
In one of the embodiments, the multifunctional spray nozzle of present invention comprises sensors selected from but not limited to flow rate sensors, blockage detectors, and material recognition sensors to dynamically adjust dispensing, spraying and broadcasting parameters of the material.
In one of the embodiments, present invention provides a base station comprising a reeling/unreeling assembly configured with spool length sensors and tension sensors for dynamically adjusting tether length in real time based on operational drone position and support drone telemetry.
In one of the embodiments, the base station of present invention further comprises a reservoir for payload storage, pumps for material propulsion, and a power supply for tethered drone system operation.
In one of the embodiments, present invention provides a tethered drone system 100 comprising sensor modules across drones (operational 140 and support 135, 137 and minion surveillance drones 145 ), comprising but not limited to GNSS (with RTK), IMU, gyroscope, ultrasonic, and LiDAR for real-time spatial positioning, obstacle mapping, and tether management.
In one of the embodiments, present invention provides an entanglement detection and prevention system configured to analyze sensor data and autonomously adjust the spatial positions of support drones to avoid tether crossover/entanglement and maintain optimal curvature of the tether.
In one of the embodiments, the anti-clogging system of present invention is triggered automatically by the base station 105 or drone controller based on flow anomalies detected via embedded sensors.
In one of the embodiments, present invention provides a tethered drone system further comprising one or more minion surveillance drones 145 independently operable and equipped with sensors (in addition to the sensors in operational and support drones) for soil nutrient monitoring, pest detection, and field data analysis.
In one of the embodiments, present invention provides a tethered drone system wherein drone-to-drone and base-to-drone communication is facilitated via GNSS with RTK correction modules for micro-positioning, enabling path repeatability and precision field coverage.
In one of the embodiments, the positioning data of the present invention provides is fused with INS feedback to maintain tether and drone stability even under weak/partial GPS signal loss or interference.
In one of the embodiments, present invention provides a drone system controller at the base station 105 configured to process telemetry from drones, interpret sensor inputs, and coordinate reeling/unreeling, anti-clogging operations, and spatial tether management in real time operations.
In one of the embodiments, the drone controller system of present invention comprises mechanism including but not limited to, predicting obstacle movement, planning dynamic tether curvature, and optimizing payload deployment sequences.
In one of the embodiments, a tethered drone system for aerial application operations in agriculture, comprising:
(a) a base station 105 configured with a reeling/unreeling mechanism, power supply, pump, payload reservoirs, and control unit;
(b) a multichannel tether 130 operatively connected at one end to the base station and at the other end to an operational drone;
(c) the operational drone 140 configured to receive electrical power and multiple types of payloads from the base station 105 via the multi-channel tether 130and to apply said payloads over a target area;
(d) a plurality of support drones 135, 137 operatively associated with the multichannel tether 130, wherein:
(i) at least one of the supporting drones is fixedly attached137 to the tether at a non-insulated power dock for mechanical support and electrical power extraction, and/or
(ii) at least one of the supporting drones comprises a pass-through loop 135 allowing the tether to freely move through it, and is powered via wireless inductive charging;
(e) an entanglement detection and prevention mechanism configured to dynamically manage the position and movement of the supporting drones 135, 137 and/or tether to avoid tether crossover, field obstacles, or no-fly zones, based on sensor(s) 150 along with GPS, Inertial Navigation Systems (INS), ultrasonic, laser, sensors and gyroscopic data; and
(f) a drone system controller configured to coordinate the operation of the base station 105, operational drone 140, supporting drones 135, 137, and tether management system.
In one of the embodiments, the system as disclosed in the present invention wherein the multichannel tether comprises at least three channels, wherein the channels provide:
(a) continuous electrical power supply,
(b) liquid payload delivery, and
(c) solid or granular payload delivery.
In one of the embodiments, the system as disclosed in the present invention, wherein the channel for solid payloads delivery comprises a helical or screw-based propulsion mechanism similar to Archimedes screw mechanism within the tether 130.
In one of the embodiments, the system as disclosed in the present invention, wherein the fixed support drones 137 are configured to detach and reposition along the tether during reeling/unreeling operations and mechanism.
In one of the embodiments, the system as disclosed in the present invention, wherein the pass-through loop supporting drones 135 are configured to remain stationary while allowing back and forth movement of the tether through the loop (135b).
In one of the embodiments, the system as disclosed in the present invention, wherein the pass-through loop supporting drones 135 receive power via wireless induction technology by using inductive coils present in the loop (135b) or embedded in the tether 130.
In one of the embodiments, the system as disclosed in the present invention, wherein the reeling/unreeling mechanism comprises a motorized spool 113, a tension sensor, spool length sensors and drone controller system for adjusting tether length based on the operational drone’s position and field layout.
In one of the embodiments, the system as disclosed in the present invention, wherein the reeling/unreeling mechanism coordinates with supporting drones (135, 137) to maintain a predefined tether curvature in three-dimensional space during tether extension or retraction (unreeling or reeling operations).
In one of the embodiments, the system as disclosed in the present invention, wherein the entanglement detection and prevention mechanism comprises a GPS-based feedback loop that predicts operational drone crossover events and instructs support drones to adjust position accordingly.
In one of the embodiments, the system as disclosed in the present invention, wherein the entanglement detection and prevention mechanism further comprises one or more of sensors 150 selected from the group comprising of laser sensors, optical sensors, ultrasonic sensors, gyroscopes or combinations thereof.
In one of the embodiments, the system as disclosed in the present invention, wherein the multichannel tether includes an anti-clogging mechanism comprising mechanical vibration elements/modules 155 embedded at selected points along the tether 130.
In one of the embodiments, the system as disclosed in the present invention, wherein the mechanical vibration elements/modules are piezoelectric actuators or vibration motors regulated through the tether or supporting drones.
In one of the embodiments, the system as disclosed in the present invention, wherein the drone system controller is configured to detect flow rate anomalies or pressure build-up and trigger the anti-clogging mechanism automatically.
In one of the embodiments, the system as disclosed in the present invention, wherein the operational drone comprises a multifunctional nozzle 143 configured to dispense different payload material selected from the group comprising liquids, solids, seeds, granules, and foams through a common outlet.
In one of the embodiments, the system as disclosed in the present invention, wherein the multifunctional nozzle 143 comprises embedded sensors selected from flow rate sensors, blockage detectors, or material-type recognition sensors.
In one of the embodiments, the system as disclosed in the present invention, further comprising one or more minion surveillance drones 145 not connected to the tether 130, configured for real-time crop and soil analytics, allowing targeted delivery of inputs and payloads along with real-time field optimization monitor field conditions, and provide feedback to the operational drone 140 and/or base station 105 for targeted payload application.
In one of the embodiments, the present invention discloses a method for performing aerial application using a tethered drone system, the method comprising the steps of:
(a) connecting one end of a multichannel tether 130 to a base station 105 and the other end to an operational drone 140;
(b) supplying electrical power and multiple types of payloads including liquids and solids from the base station 105 to the operational drone 140 through said multichannel tether 130;
(c) positioning a plurality of supporting drones 135, 137 along the tether 130, wherein:
(i) at least one supporting drone is fixedly attached at a power dock and receives power via direct tether contact, and/or
(ii) at least one supporting drone 135 comprises a pass-through loop through which the tether passes freely and receives power wirelessly;
(d) controlling the position and configuration of the supporting drones 135,1 37 to maintain an elevated and obstacle-free curvature of the tether;
(e) detecting and preventing potential tether entanglement using sensor modules that dynamically adjusts drone positioning; and
(f) performing aerial application of the payloads from the operational drone over a target area.
In one of the embodiments, the present invention discloses a method, wherein the step of supplying multiple types of payloads comprises:
(a) transporting liquids via a pressurized channel 132 using pumps at the base station 105, and
(b) transporting solids or granules via a channel 131 using a helical or screw-based propulsion mechanism similar to Archimedes screw mechanism within the tether 130.
In one of the embodiments, the present invention discloses a method, further comprising:
(a) adjusting the length of the tether by reeling or unreeling the tether at the base station 105 using a motorized drum 113,
(b) coordinating the tether extension or retraction with the repositioning of the supporting drones to maintain continuous aerial operation and tether suspension.
In one of the embodiments, the present invention discloses a method, wherein the step of detecting and preventing entanglement comprises:
(a) monitoring GPS data and relative positions of the drones,
(b) detecting potential tether crossover paths between the operational drone 140 and supporting drones (135, 137), and
(c) instructing supporting drones (135, 137) to adjust their position or altitude to prevent tether 130 crossover or entanglement guided by the drone controller system.
In one of the embodiments, the present invention discloses a method, further comprising the step of:
(a) detecting flow rate anomalies or material blockages in the tether using embedded sensors, and
(b) triggering an anti-clogging mechanism comprising mechanical vibrations to dislodge residue or stuck material.
In one of the embodiments, the present invention discloses a method, wherein the vibrations are generated by vibration element/module 155 selected from the group comprising piezoelectric actuators or vibration motors or combinations thereof, integrated within the tether 130 or powered via supporting drones 135,137.
In one of the embodiments, the present invention discloses a method, wherein the operational drone 140 comprises a multifunctional nozzle 143 that adjusts the spray pattern, particle output, or flow rate based on the type of material fed to the operational drone 140.
In one of the embodiments, the present invention discloses a method, wherein the nozzle 143 comprises one or more sensors selected from the group comprising of flow rate sensors, material recognition sensors, or blockage detectors, or combinations thereof.
In one of the embodiments, the present invention discloses a method, further comprising the step of deploying one or more minion surveillance drones 145 to scan the field and provide real-time feedback on pest infestation, soil conditions, or crop health to adjust the type or rate of payload application.
In one of the embodiments, the present invention provides a tethered drone system comprising:
i. a base station 105,
ii. an operational drone 140,
iii. a plurality of support drones 135, 137, and
iv. a multichannel tether 130, wherein said multichannel tether 130 is configured for simultaneous transmission of electrical power and delivery of multiple types of agricultural payloads selected from the group comprising but not limited to liquids, solids, granules, seeds, foams, and gases, etc or combinations thereof.
In one of the embodiments, the tethered drone system as disclosed in the present invention, wherein the base station comprises:
i. a power supply 107 module configured to deliver electrical power through at least one channel 133 of the multichannel tether 130;
ii. a reeling/unreeling drum assembly with motorized control 113 and integrated sensors for tension and spool length;
iii. a drone controller system for monitoring drone telemetry and coordinating tether adjustments; and
iv. at least one payload supply subsystem including a reservoir and a delivery pump 115, 117 for transferring agricultural payloads through the tether 130.
In one of the embodiments, the tethered drone system as disclosed in the present invention, wherein the reeling/unreeling mechanism is integrated with tension sensors and spool length sensors to dynamically adjust tether length.
In one of the embodiments, the tethered drone system 100 as disclosed in the present invention, wherein the base station 105 further comprises a GNSS-RTK module for real-time positional correction and communication with onboard drone GNSS receivers to enhance micro-positioning and tether alignment.
In one of the embodiments, the tethered drone system as disclosed in the present invention, wherein the drone controller system is configured to coordinate operations of the operational drone 140, support drones 135, 137, and reeling/unreeling mechanism based on sensor feedback, entanglement detection and prevention mechanism, and predefined mission parameters.
In one of the embodiments, the tethered drone system 100 as disclosed in the present invention, wherein the support drones are selected from fix attachment support drone 137 or pass-through loop support drone 135.
In one of the embodiments, the tethered drone system as disclosed in the present invention, wherein the fix attachment support drones 135 are mechanically and electrically connected to the tether at non-insulated contact points referred to as power docks 160.
In one of the embodiments, the tethered drone system as disclosed in the present invention, wherein at least one support drone comprises a pass-through loop configuration 135 allowing free tether motion and is powered via inductive wireless charging.
In one of the embodiments, the tethered drone system as disclosed in the present invention, wherein the system further comprises a plurality of sensors including but not limited to GPS, AGPS, GNSS, RTK, gyroscopes, IMUs, LiDAR, optical, and ultrasonic sensors for tether geometry management and obstacle detection.
In one of the embodiments, the tethered drone system as disclosed in the present invention, wherein the system comprises an entanglement detection and prevention mechanism configured to reposition support drones to avoid tether crossover or entanglement using trajectory prediction.
In one of the embodiments, the tethered drone system as disclosed in the present invention, further comprising an anti-clogging mechanism integrated into at least one support drone or tether node, wherein said mechanism includes a vibration-inducing module 155 for dislodging material buildup within the tether.
In one of the embodiments, the tethered drone system as disclosed in the present invention, wherein the operational drone comprises a multifunctional nozzle 143 configured to adaptively dispense multiple payload types via a unified outlet.
In one of the embodiments, the tethered drone system as disclosed in the present invention, wherein the system further comprises minion surveillance drones 145 operable without tether connection, configured for field monitoring, pest detection, and environmental sensing.
In one of the embodiments, the tethered drone system as disclosed in the present invention, which comprises:
i. receiving telemetry and sensor data from the operational drone 140 and support drones 135, 137,
ii. controlling a reeling/unreeling mechanism at the base station 105 based on said data,
iii. adjusting the tether length dynamically to maintain operational continuity.
In one of the embodiments, the tethered drone system 100 as disclosed in the present invention, wherein support drones reposition based on predicted crossover risks calculated using GPS, trajectory data, and onboard sensor fusion.
In one of the embodiments, the tethered drone system 100 as disclosed in the present invention, further comprising activating vibration-based anti-clogging modules upon detection of pressure buildup or flow rate anomalies within the tether.
In one of the embodiments, the tethered drone system as disclosed in the present invention, further comprising adapting the operational drone’s spray pattern using sensor-based detection of payload material type and field conditions.
In one of the embodiments, the tethered drone system as disclosed in the present invention, further comprising micro-positioning the drones using GNSS integrated with RTK correction signals for high-precision spatial management of tether and drone alignment.
These embodiments can be separately or jointly implemented and are not intended to limit the scope of the invention, but to illustrate potential applications and implementations in alignment with the novel and inventive concept of the present invention.
Although this invention has been disclosed in the context of certain preferred embodiments and examples, it will be understood by those skilled in the art that the present invention extends beyond the specifically disclosed embodiments to other alternative embodiments and/or uses of the invention and obvious modifications and equivalents thereof. Thus, from the foregoing description, it will be apparent to one of ordinary skill in the art that many changes and modifications can be made thereto without departing from the spirit or scope of the invention as set forth herein.
Accordingly, it is not intended that the scope of the foregoing description be limited to the description set forth above, but rather that such description be construed as encompassing all of the features of patentable novelty that reside in the present invention, including all the features and embodiments that would be treated as equivalents thereof by those skilled in the relevant art. Thus, it is intended that the scope of the present invention herein disclosed should not be limited by the particular disclosed embodiments described above but should be determined only by a fair reading of complete specification to follow.
It is to be understood that the present invention is susceptible to modifications, changes and adaptations by those skilled in the art. Such modifications, changes, adaptations are intended to be within the scope of the present invention.
,CLAIMS:We Claim:
1. A tethered drone system (100) for aerial operations in agriculture, comprising:
a) a base station (105) configured to supply electrical power and deliver one or more payloads through a multichannel tether (130), the base station (105) comprising:
i. a reeling/unreeling mechanism (113);
ii. one or more payload reservoirs (109, 111);
iii. one or more pumps (115, 117); and
iv. a drone controller system;
b) an operational drone (140) operatively connected to the multichannel tether (130), wherein the operational drone (140) is configured to:
i. receive electrical power and agricultural payloads via the tether (130); and
ii. apply said payloads over a designated field area;
c) a plurality of support drones (135, 137) associated with the tether (130), wherein:
i. at least one support drone (137) is mechanically and electrically coupled to the tether (130) at a non-insulated power dock (160); and
ii. at least one support drone (135) comprises a pass-through loop that allows the tether (130) to move freely and is powered via wireless inductive charging;
d) a tether control mechanism configured to monitor and adjust the tether (130) curvature, elevation, and length during aerial operation, including by coordinating movement of the support drones (135, 137) and reeling/unreeling mechanism (113);
e) an entanglement detection and prevention mechanism configured to detect potential tether (130) crossovers, collisions, or obstacles using sensor data (150), including geo-positional and proximity information, and to reposition the support drones (135, 137) accordingly; and
f) a drone system controller configured to coordinate the operation of the base station (105), operational drone (140), and support drones (135, 137) based on pre-programmed instructions and real-time sensor data.

2. The tethered drone system (100) as claimed in claim 1, wherein the multichannel tether (130) comprises at least three internal channels configured respectively for:
(a) transmission of electrical power,
(b) delivery of liquid payloads, and
(c) delivery of solid or granular payloads.
3. The tethered drone system (100) as claimed in claim 2, wherein the channel for solid or granular payload delivery includes a helical or screw-based propulsion mechanism for transport within the tether (130).
4. The tethered drone system (100) as claimed in claim 1, wherein the reeling/unreeling mechanism (113) comprises a motorized spool, a tension sensor, and a positional feedback system for adjusting the tether (130) length based on operational drone (140) movement.
5. The tethered drone system (100) as claimed in claim 4, wherein the reeling/unreeling mechanism (113) operates in coordination with the support drones (135, 137) to maintain a predetermined tether profile during extension or retraction.
6. The tethered drone system (100) as claimed in claim 1, wherein the entanglement detection and prevention mechanism utilizes sensor data (150) from one or more of: GPS, AGPS, laser sensor, ultrasonic sensor, optical sensor, gyroscope, and inertial navigation systems.

7. The tethered drone system (100) as claimed in claim 6, wherein the entanglement detection and prevention mechanism predicts crossover or tangling events based on geo-positional data and issues repositioning commands to the support drones (135, 137).
8. The tethered drone system (100) as claimed in claim 1, wherein one or more of the support drones (135, 137) are configured to autonomously reposition in horizontal or vertical directions to manage tether (130) tension and avoid obstacles.
9. The tethered drone system (100) as claimed in claim 1, wherein the multichannel tether (130) includes an anti-clogging mechanism comprising vibration elements positioned along the tether length.
10. The tethered drone system (100) as claimed in claim 9, wherein the vibration elements comprise piezoelectric actuators or vibration motors embedded in or attached to the tether (130) and are activated upon detection of flow anomalies or pressure buildup.
11. The tethered drone system (100) as claimed in claim 10, wherein the drone system controller is configured to automatically trigger the anti-clogging mechanism based on sensor input indicating blockage or irregular flow.
12. The tethered drone system (100) as claimed in claim 1, wherein the operational drone (140) comprises a multifunctional nozzle (143) configured to dispense multiple types of payloads including liquids, granules, seeds, powders, and foams.
13. The tethered drone system (100) as claimed in claim 12, wherein the multifunctional nozzle (143) comprises embedded sensors (150) configured to detect flow rate, material type, or blockages.
14. The tethered drone system (100) as claimed in claim 1, further comprising one or more minion surveillance drones (145) operatively independent from the tether (130), configured to scout the field, monitor pest and crop conditions, and transmit data to the operational drone (140) or base station (105) for precision application of payloads.
15. The tethered drone system (100) as claimed in claim 1, wherein the support drones (135, 137) are selectively detachable and configured to park on a docking platform integrated with charging contacts or wireless charging capability.
16. The system as claimed in claim 1, further comprising one or more minion surveillance drones 145 not connected to the tether 130, configured for real-time crop and soil analytics, allowing targeted delivery of inputs and payloads along with real-time field optimization monitor field conditions, and provide feedback to the operational drone 140 and/or base station 105 for targeted payload application.

17. A method for performing coordinated aerial agricultural operations using a tethered drone system (100), the method comprising:
a) connecting an operational drone (140) to a base station (105) via a multichannel tether (130);
b) supplying electrical power and one or more payloads, including liquids and solids, from the base station (105) to the operational drone (140) through the multichannel tether (130);
c) positioning a plurality of support drones (135, 137) along the tether (130), wherein:
i. at least one support drone (137) is mechanically and electrically connected at a power dock (160), and
ii. at least one support drone (135) comprises a pass-through loop allowing tether movement and is powered wirelessly;
d) controlling the operational drone (140) to apply payloads over the target agricultural area;
e) managing the profile, curvature, and length of the tether (130) in real-time using a reeling/unreeling mechanism (113) and feedback from sensors (150);
f) detecting and preventing tether entanglement or crossover using sensor-based positional and obstacle data; and
g) coordinating the operation of the base station (105), operational drone (140), and support drones (135, 137) via a drone system controller.
18. The method as claimed in claim 17, wherein the multichannel tether (130) includes at least three channels for:
a) electrical power transmission,
b) liquid payload delivery, and
c) solid or granular payload delivery.
19. The method as claimed in claim 18, wherein the solid or granular payload delivery is performed using a screw-based propulsion mechanism integrated within the tether (130).
20. The method as claimed in claim 17, wherein the reeling/unreeling mechanism (113) includes a motorized spool and a tension sensor to dynamically adjust tether length based on the position of the operational drone (140).
21. The method as claimed in claim 20, wherein the tether (130) length adjustment is coordinated with support drone repositioning to maintain aerial clearance and optimal curvature.
22. The method as claimed in claim 17, wherein the entanglement detection and prevention comprises:
a) collecting positional and environmental data from sensors (150) on support drones (135, 137), and
b) repositioning said support drones to avoid tether collisions, crossover, or contact with obstacles or no-fly zones.
23. The method as claimed in claim 22, wherein the sensors (150) include at least one of: GPS, laser sensor, ultrasonic sensor, optical sensor, gyroscope, or inertial navigation system (INS).
24. The method as claimed in claim 17, wherein the tether (130) includes vibration elements configured to prevent clogging of internal payload channels during operation.
25. The method as claimed in claim 24, wherein the vibration elements are activated automatically upon detection of a pressure build-up or flow rate anomaly within the tether (130).
26. The method as claimed in claim 17, wherein the operational drone (140) comprises a multifunctional nozzle (143) configured to dispense liquids, solids, foams, granules, or seeds.
27. The method as claimed in claim 26, wherein the nozzle (143) includes embedded sensors (150) to monitor flow characteristics, detect blockages, or identify material type.
28. The method as claimed in claim 17, further comprising the step of deploying one or more minion surveillance drones (145) not connected to the tether (130), to scout field conditions and provide feedback to the operational drone (140) or base station (105) for precision targeting of payloads.
29. The method as claimed in claim 17, wherein at least one support drone (135, 137) is detached or repositioned autonomously based on the field layout or tether curvature requirements.
30. The method as claimed in claim 17, wherein the drone system controller synchronizes aerial operations using pre-programmed flight paths and real-time sensor input for dynamic adjustments during payload application.
31. An operational drone (140) for use in a tethered agricultural aerial system (100), the drone comprising:
(a) a tether interface configured to connect with a multichannel tether (130) and receive:
(i) electrical power, and
(ii) one or more types of agricultural payloads including liquids, solids, granules, foams, or gases;
(b) one or more propulsion systems configured to enable stable aerial maneuvering during tethered operation;
(c) a multifunctional nozzle (143) operatively coupled to the tether interface and configured to dispense said payloads over a target agricultural region;
(d) at least one onboard sensor (150) selected from the group comprising: flow rate sensor, blockage detector, material detection sensor, GPS, or gyroscope;
(e) a drone controller configured to execute commands from a central drone system controller, monitor payload dispensing operations, and adjust flight parameters based on real-time environmental and sensor data; and
(f) a structural configuration compatible with dynamic tether movement, supporting uninterrupted aerial operation during payload application.
32. The operational drone (140) as claimed in claim 31, wherein the tether interface comprises separate channels for electrical power, liquid payloads, and solid or granular payloads.
33. The operational drone (140) as claimed in claim 31, wherein the multifunctional nozzle (143) is capable of switching between multiple spray patterns or particle sizes based on the material type.

34. The operational drone (140) as claimed in claim 31, wherein the onboard sensor (150) includes an integrated inertial navigation system (INS) for improved flight stability.
35. The operational drone (140) as claimed in claim 31, wherein the drone controller is configured to trigger an emergency cutoff or hover command if tether strain exceeds a predefined threshold.
36. The operational drone (140) as claimed in claim 31, wherein the nozzle (143) includes a clogging detection feature that activates a cleaning or reverse-flow cycle upon blockage.
37. The operational drone (140) as claimed in claim 31, wherein the drone further comprises a secondary docking interface to allow optional charging or communication via a docking platform.

38. A multichannel tether system (130) for use in a tethered aerial drone system (100), the tether system comprising:
(a) an elongated flexible tubular body configured to interconnect a base station (105) with an aerial operational drone (140);
(b) a plurality of internally segregated channels extending along the length of the tether, including:
(i) an electrical power transmission channel configured to deliver continuous electrical energy from the base station (105) to the operational drone (140);
(ii) a fluid transport channel configured to deliver liquid agricultural payloads; and
(iii) a solid or granular transport channel configured for delivery of solid payloads, seeds, or granules;
(c) one or more anti-clogging structures embedded along the tether, configured to prevent accumulation or blockage of payload materials during transmission;
(d) a structural interface for coupling with support drones (135, 137), wherein:
(i) at least one attachment point is configured as a power dock (160) for fixed support drone connection and energy transfer; and
(ii) at least one loop segment is configured for free passage through a pass-through support drone (135); and
(e) embedded sensor connections configured to enable tether curvature monitoring, tension feedback, or flow rate sensing during aerial operation.
39. The tether system as claimed in claim 38, wherein the solid transport channel includes a helical or screw-based propulsion mechanism for transporting solids.
40. The tether system as claimed in claim 38, wherein the anti-clogging structures comprise piezoelectric vibrators or mechanical vibratory elements (155) positioned at intervals along the tether.
41. The tether system as claimed in claim 38, wherein the electrical channel is configured with insulated conductors shielded from the payload-carrying channels.
42. The tether system as claimed in claim 38, wherein the tether includes inductive coils embedded for wireless power transfer to pass-through loop support drones (135).
43. The tether system as claimed in claim 38, further comprising positional markers or embedded RFID tags along its length to assist in drone alignment and automated tether management.
44. The tether system as claimed in claim 38, wherein sensor interfaces are configured to transmit data to a drone system controller for real-time reeling/unreeling control based on operational conditions.
45. A base station assembly (105) for use in a tethered drone system (100) for aerial agricultural operations, the base station assembly comprising:
(a) a multichannel tether interface configured to operatively connect to a multichannel tether (130) for transmitting electrical power and agricultural payloads to an operational drone (140);
(b) a power supply unit (107) configured to deliver electrical energy through the tether (130) to the operational drone (140) and one or more support drones (135, 137);
(c) one or more payload reservoirs (109, 111) configured to store liquid and/or solid agricultural payloads;
(d) one or more pumps (115, 117) fluidly coupled with the payload reservoirs, and configured to inject payloads into corresponding internal channels of the tether (130);
(e) a reeling/unreeling mechanism (113) comprising a motorized spool and a tension sensing system, adapted to dynamically adjust the length of the tether (130); and
(f) a drone controller system configured to coordinate power and payload delivery, tether deployment, and operational control of the tethered drone system (100) based on sensor input and pre-programmed instructions.
46. The base station assembly as claimed in claim 45, wherein the reeling/unreeling mechanism (113) comprises spool length sensors and tension sensors configured to regulate tether (130) curvature and prevent slack or entanglement during operation.
47. The base station assembly as claimed in claim 45, wherein the controller system is configured to receive telemetry and positional data from the operational drone (140) and support drones (135, 137), and to adjust the tether length accordingly.
48. The base station assembly as claimed in claim 45, wherein the payload reservoirs (109, 111) are modular and interchangeable based on the type of payload being dispensed, selected from liquids, solids, granules, seeds, or foams.
49. The base station assembly as claimed in claim 45, wherein the controller system is configured to monitor pressure and flow rate within the tether (130) and activate an anti-clogging mechanism when anomalies are detected.
50. The base station assembly as claimed in claim 45, wherein the drone controller system is configured to communicate wirelessly with untethered minion surveillance drones (145) for receiving field data and adjusting payload application dynamically.
51. The base station assembly as claimed in claim 45, wherein the controller system further comprises a flight management interface configured to execute pre-programmed operational paths and dynamically adjust reeling based on real-time data.