Description:PREAMBLE TO THE DESCRIPTION
The following specification particularly describes the invention and the manner in which it is to be performed.

VARIABLE PITCH PROPELLER (VPP) SYSTEM AND METHOD FOR MANAGING OPERATIONAL CONDITIONS OF AN AIRCRAFT

TECHNICAL FIELD
Embodiments of the present disclosure generally relate to propeller systems, and more particularly relate to a Variable Pitch Propeller (VPP) system and a method for managing operational conditions of an aircraft.

BACKGROUND
Generally, aircrafts or aerial vehicles, including quadcopters, represent ground-breaking advancements in aviation technology, revolutionizing industries ranging from entertainment to agriculture and public safety and security. Quadcopters, provide unparalleled maneuverability, versatility, and accessibility, enabling to be indispensable tools in various applications. As the aerial vehicles capable of vertical takeoff and landing (VTOL), quadcopters utilize sophisticated control systems and propulsion mechanisms to achieve stable flight. The compact size, agility, and ability to hover enable the aerial vehicle ideal for tasks such as aerial photography and videography, surveillance, search and rescue operations, and package delivery. The rapid proliferation of quadcopter technology has spurred innovation in areas such as battery efficiency, sensor integration, and autonomous navigation, further enhancing capabilities and expanding potential applications of the aerial vehicles. Despite small size, the aerial vehicles embody the ingenuity and engineering prowess driving advancements in modern aviation, promising to shape the future of airborne transportation and beyond.
Further, despite versatility, the aerial vehicles with standard Fixed-Pitch-Propellers (FPPs) face limitations in power efficiency, maneuverability, and actuator fault-tolerance, prompting the exploration of innovative solutions to overcome the constraints. Some of the aerial vehicles use Variable-Pitch-Propellers (VPPs) on all four actuators to solve some fundamental limitations of the standard FPPs-driven aerial vehicles. The VPPs-based aerial vehicles provide higher maneuverability and response time compared to a standard quadcopter based aerial vehicles. The higher maneuverability is due to faster change in a propeller pitch angle compared to changing of respective Revolutions Per Minute (RPM).
Further, on the FPPs-driven aerial vehicles, a given thrust can be generated by mainly controlling the RPM of the motor. However, in the VPP-driven aerial vehicles, the propeller pitch can be controlled in addition to the motor RPM. Therefore, a given thrust can be generated by multiple combinations of propeller pitch angle and the RPM. For example, the same thrust may be generated by the propeller set at a higher pitch angle and spinning at low RPM or the propeller set at a lower pitch angle but spinning at higher RPM. This actuator redundancy in VPP may be resolved to optimize the VPP-driven aerial vehicles power consumption. However, the pitch remains constant throughout the flight in the VPP-driven aerial vehicles. For truly extracting the benefit of actuator redundancy, the propeller pitch should adapt to external factors such as wind disturbances throughout the flight envelope.
Conventional systems provide a multirotor drone utilizing at least three non-coaxial rotors to generate lift, with each rotor contributing significantly to the overall lift. The conventional multirotor drone includes a central cell connected to multiple motorized spindles, spaced apart, with each spindle linked to a variable-pitch rotor assembly. The assembly of the conventional multirotor drone includes a module for adjusting collective pitch and twisted blades, enabling lift control during flight. Another conventional system provides the VPP enabling actuator Fault-Tolerant-Control (FTC) in situations such as a multirotor failure due to overheating, propeller strike, winding ingress, and the like. The performance of the VPP under actuator loss of effectiveness wherein the actuator provides lesser control effort than expected. Although the attitude references are tracked well, the system is not designed for a complete failure of an actuator. The pitch-stuck fault of a centrally powered VPP quadcopter where all the propellers are constrained to spin at the same RPM. Currently, conventional VPP-driven aerial vehicles may not fly with full-attitude control under the complete failure of an actuator. Also, the conventional VPP-driven aerial vehicles include an additional mechanism to control the propeller pitch angle. However, the VPP-driven aerial vehicles do not include mechanism to ensure linearity in a control input-output relationship, to avoid singularities, to minimize vibrations, and the like.
Consequently, there is a need in the art for an improved Variable Pitch Propeller (VPP) system and a method for managing operational conditions of an aircraft, to address at least the aforementioned issues in the prior arts.

SUMMARY
This summary is provided to introduce a selection of concepts, in a simple manner, which is further described in the detailed description of the disclosure. This summary is neither intended to identify key or essential inventive concepts of the subject matter nor to determine the scope of the disclosure.
An aspect of the present disclosure provides a Variable Pitch Propeller (VPP) system for managing operational conditions of an aircraft. The VPP system includes a plurality of actuator units. The plurality of actuator units includes a plurality of variable-pitch propeller (VPP) blades including one or more cambered air foils, configured to rotate in axial-direction and spaced apart in circumferential-direction. Each of the plurality of VPP blades is rotatable through a plurality of propeller blade angles corresponding to respective variable pitch axes each extending in radial direction. Further, the plurality of actuator units includes a plurality of foldable arms, including one or more connecting links, coupled to a proximal end of each of the plurality of VPP blades. The plurality of foldable arms is configured to control the plurality of propeller blade angles corresponding to the respective variable pitch axes. Furthermore, the plurality of actuator units includes a plurality of elongated shafts comprising a proximal portion and a distal portion. The proximal portion of each of the plurality of elongated shafts is coupled to each of the plurality of VPP blades. Furthermore, the distal portion of each of the plurality of elongated shafts is coupled to at least one of a landing gear and a stud.
Additionally, the plurality of actuator units includes a plurality of rotors including at least one of Direct Current (DC) motors and Internal Combustion Engines (ICEs) rotatably coupled to an intermediate portion of each of the plurality of elongated shafts. Each of at least one of the DC motors and the ICEs is configured to rotate each of the plurality of elongated shafts. Furthermore, the plurality of actuator units includes a plurality of frame structures comprising a proximal portion and a distal portion. The proximal portion of each of the plurality of frame structures is mounted, via a motor mount plate structure, to at least one of the DC motors and the ICEs, and the distal portion of each of the plurality of frame structures is mounted to at least one of the landing gear and the stud. Each of the plurality of frame structures comprises a guided slot on an inner surface.
Furthermore, the VPP system includes a plurality of auxiliary actuator units are coupled to the plurality of actuator units via the plurality of frame structures. Each of the plurality of auxiliary actuator units includes a servo-motor coupled to a servo-motor horn within each of the plurality of frame structures, configured to control, via each of the plurality of elongated shafts, the plurality of propeller blade angles corresponding to the respective variable pitch axes. The servo-motor horn is configured to convert circular motion of the servo-motor into liner motion for each of the plurality of elongated shafts. Further, the VPP system includes a plurality of sensors mounted in proximity to each of the plurality of actuator units and each of the plurality of auxiliary actuator units.
Additionally, the VPP system includes a control unit communicatively coupled to each of the plurality of actuator units and each of the plurality of auxiliary actuator units. The control unit includes a processor and a memory. The memory includes processor-executable instructions, which on execution, cause the processor to receive, dynamically, operational status data corresponding to an operation of each of the plurality of actuator units and each of the plurality of auxiliary actuator units, from each of the plurality of sensors. Furthermore, the processor is configured to receive one or more control parameters corresponding to an operation control of an aircraft, from a remote-control unit communicatively coupled to the control unit. The one or more control parameters includes one or more direction control parameters and one or more mid-flight flip maneuver parameters. Furthermore, the processor is configured to analyze one or more operational parameters from the operational status data received from each of the plurality of sensors. Additionally, the processor is configured to identify one or more types of fault conditions in each of the plurality of actuator units and each of the plurality of auxiliary actuator units, based on the analyzed one or more operational parameters.
Further, the processor is configured to determine one or more failure control parameters for each of the plurality of actuator units and each of the plurality of auxiliary actuator units, based on the identified the one or more types of fault conditions, using the NN-based technique. Furthermore, the processor is configured to control at least one of a stability parameter, an attitude parameter, and an equilibrium parameter of each of the plurality of actuator units and each of the plurality of auxiliary actuator units, based on the determined one or more failure control parameters, by varying at least one of the plurality of propeller blade angles corresponding to respective variable pitch axes, a thrust and a torque. Furthermore, the processor is configured to manage one or more operational conditions of the aircraft based on controlling at least one of the stability parameter, the attitude parameter, the equilibrium parameter, and the received, from the remote-control unit, one or more control parameters corresponding to the operational control of the aircraft.
Another aspect of the present disclosure provides a method for managing operational conditions of an aircraft using a Variable Pitch Propeller (VPP) system, The method includes receiving dynamically, operational status data corresponding to an operation of each of a plurality of actuator units and each of a plurality of auxiliary actuator units associated with a Variable Pitch Propeller (VPP) system, from each of a plurality of sensors. Further, the method includes receiving one or more control parameters corresponding to an operation control of an aircraft, from a remote-control unit. The one or more control parameters includes one or more direction control parameters and one or more mid-flight flip maneuver parameters. Additionally, the method includes analyzing one or more operational parameters from the operational status data received from each of the plurality of sensors. Further, the method includes identifying one or more types of fault conditions in each of the plurality of actuator units and each of the plurality of auxiliary actuator units, based on the analyzed one or more operational parameters.
Further, the method includes determining one or more failure control parameters for each of the plurality of actuator units and each of the plurality of auxiliary actuator units, based on the identified one or more types of fault conditions, using the NN-based technique. Furthermore, the method includes controlling at least one of a stability parameter, an attitude parameter, and an equilibrium parameter of each of the plurality of actuator units and each of the plurality of auxiliary actuator units, based on the determined one or more failure control parameters, by varying at least one of the plurality of propeller blade angles corresponding to respective variable pitch axes, a thrust and a torque. Additionally, the method includes managing one or more operational conditions of the aircraft based on controlling at least one of the stability parameter, the attitude parameter, the equilibrium parameter, and the received, from the remote-control unit, one or more control parameters corresponding to the operational control of the aircraft.
To further clarify the advantages and features of the present disclosure, a more particular description of the disclosure will follow by reference to specific embodiments thereof, which are illustrated in the appended figures. It is to be appreciated that these figures depict only typical embodiments of the disclosure and are therefore not to be considered limiting in scope. The disclosure will be described and explained with additional specificity and detail with the appended figures.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
The accompanying drawings, which are incorporated in and constitute a part of this disclosure, illustrate exemplary embodiments and, together with the description, serve to explain the disclosed principles. In the figures, the left-most digit(s) of a reference number identifies the figure in which the reference number first appears. The same numbers are used throughout the figures to reference like features and components. Some embodiments of system and/or methods in accordance with embodiments of the present subject matter are now described, by way of example only, and with reference to the accompanying figures, in which:
FIG. 1 illustrates a block diagram representation of a network architecture of a Variable Pitch Propeller (VPP) system for managing operational conditions of an aircraft, in accordance with some embodiments of the present disclosure;
FIG. 2 illustrates a block diagram representation of a proposed control unit such as those shown in FIG. 1, capable of managing operational conditions of an aircraft, in accordance with some embodiments of the present disclosure;
FIG. 3A illustrates a front view of a schematic diagram representation of a Variable Pitch Propeller (VPP) technique of an actuator unit in an aircraft, in accordance with some embodiments of the present disclosure;
FIG. 3B illustrates a front view of a schematic diagram representation of a scenario of first kind of singularity in a Variable Pitch Propeller (VPP) technique of an actuator unit in an aircraft, in accordance with some embodiments of the present disclosure;
FIG. 3C illustrates a front view of a schematic diagram representation of a scenario of second kind of singularity in a Variable Pitch Propeller (VPP) technique of an actuator unit in an aircraft, in accordance with some embodiments of the present disclosure;
FIG. 4 illustrates a block diagram of an actuator unit with a landing gear, or a stud associated with a Variable Pitch Propeller (VPP) system of an aircraft, in accordance with some embodiments of the present disclosure;
FIG. 5 illustrates a front view of a stand-off associated with an actuator unit, in accordance with some embodiments of the present disclosure;
FIG. 6 illustrates an example aircraft with Heli-quad prototype including actuator units and struts, in accordance with some embodiments of the present disclosure;
FIG. 7A illustrates a perspective view of a plurality of variable-pitch propeller (VPP) blades associated with the actuator unit of the VPP system, in accordance with some embodiments of the present disclosure;
FIG. 7B illustrates a side view of a zero-recoil mount unit associated with a variable-pitch propeller (VPP) blades in the actuator unit, in accordance with some embodiments of the present disclosure;
FIG. 7C illustrates a schematic diagram and a graph diagram representation of comparison between typical symmetric and cambered airfoil associated with a plurality of variable-pitch propeller (VPP) blades, in accordance with some embodiments of the present disclosure;
FIG. 8 illustrates a block diagram representation of input and output commands for control allocation technique of autopilot in an aircraft, in accordance with some embodiments of the present disclosure;
FIG. 9 illustrates a graph diagram representation of a step input tracking performance comparison between a Fixed-Pitch-Propeller (FPPs)- based actuator and a Variable Pitch Propeller (VPP)-based actuator, in accordance with some embodiments of the present disclosure;
FIG. 10 illustrates an example Neural Network (NN) architecture associated with a control unit, for generating desired thrust or torque commands for actuator units, in accordance with some embodiments of the present disclosure; and
FIG. 11 illustrates a flow chart depicting a method for managing operational conditions of an aircraft using a Variable Pitch Propeller (VPP) system, in accordance with some embodiments of the present disclosure.
Further, those skilled in the art will appreciate that elements in the figures are illustrated for simplicity and may not have necessarily been drawn to scale. Furthermore, in terms of the construction of the device, one or more components of the device may have been represented in the figures by conventional symbols, and the figures may show only those specific details that are pertinent to understanding the embodiments of the present disclosure so as not to obscure the figures with details that will be readily apparent to those skilled in the art having the benefit of the description herein.

DETAILED DESCRIPTION OF THE PRESENT DISCLOSURE
For the purpose of promoting an understanding of the principles of the disclosure, reference will now be made to the embodiment illustrated in the figures and specific language will be used to describe them. It will nevertheless be understood that no limitation of the scope of the disclosure is thereby intended. Such alterations and further modifications in the illustrated system, and such further applications of the principles of the disclosure as would normally occur to those skilled in the art are to be construed as being within the scope of the present disclosure. It will be understood by those skilled in the art that the foregoing general description and the following detailed description are exemplary and explanatory of the disclosure and are not intended to be restrictive thereof.
In the present document, the word “exemplary” is used herein to mean “serving as an example, instance, or illustration”. Any embodiment or implementation of the present subject matter described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other embodiments.
While the disclosure is susceptible to various modifications and alternative forms, specific embodiment thereof has been shown by way of example in the drawings and will be described in detail below. It should be understood, however that it is not intended to limit the disclosure to the forms disclosed, but on the contrary, the disclosure is to cover all modifications, equivalents, and alternative falling within the scope of the disclosure.
The terms “comprises”, “comprising”, “includes”, “including” or any other variations thereof, are intended to cover a non-exclusive inclusion, such that a setup, device or method that includes a list of components or steps does not include only those components or steps but may include other components or steps not expressly listed or inherent to such setup or device or method. In other words, one or more elements in a system or apparatus proceeded by “comprises… a” does not, without more constraints, preclude the existence of other elements or additional elements in the system or method.
Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this disclosure belongs. The system, methods, and examples provided herein are only illustrative and not intended to be limiting.
In the following specification and the claims, reference will be made to a number of terms, which shall be defined to have the following meanings. The singular forms “a,” “an,” and “the” include plural references unless the context clearly dictates otherwise.
A description of an embodiment with several components in communication with each other does not imply that all such components are required. On the contrary, a variety of optional components are described to illustrate the wide variety of possible embodiments of the invention. In the following detailed description of the embodiments of the disclosure, reference is made to the accompanying drawings that form a part hereof, and in which are shown by way of illustration specific embodiments in which the disclosure may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the disclosure, and it is to be understood that other embodiments may be utilized and that changes may be made without departing from the scope of the present disclosure. The following description is, therefore, not to be taken in a limiting sense.
In the present disclosure, terms such as “upper”, “lower”, “left”, “right”, “front”, “rear”, “vertical”, “horizontal”, “side”, “bottom”, and the like, may refer to an orientation or a positional relationship based on that shown in the drawings, and are merely relational terms, which are used for convenience in describing structural relationships of various components or elements of the present invention, and do not denote any one of the components or elements of the present disclosure, and are not to be construed as limiting the present invention.
In the present disclosure, terms such as “fixedly attached”, “movably coupled”, “connected”, “coupled”, and the like are to be construed broadly and refer to either a fixed connection, or a movable, or an integral or removable connection; can be directly connected or indirectly connected through an intermediate medium. The specific meaning of the terms in the present disclosure can be determined according to circumstances by a person skilled in the relevant art or the art and is not to be construed as limiting the present disclosure.
Embodiments of the present disclosure provides a Variable Pitch Propeller (VPP) system and a method for managing operational conditions of an aircraft. The Variable Pitch Propeller (VPP) system includes an arrangement of actuator units, each equipped with variable-pitch propeller blades and foldable arms for angle adjustment. The actuator units are intricately connected to landing gear or studs via elongated shafts, with rotors such as Direct Current (DC) motors or Internal Combustion Engines (ICEs) facilitating rotation. Frame structures house these components, along with auxiliary actuator units with servomotors for precise control. Proximity-mounted sensors gather operational data, which a central control unit analyzes to dynamically adjust parameters based on received control inputs and identify fault conditions using advanced NN-based techniques. Through the VPP system, the aircraft's operational conditions are effectively managed, ensuring stability, attitude control, and equilibrium parameters are maintained, while responding to real-time operational demands communicated by a remote-control unit.
Referring now to the drawings, and more particularly to FIGs. 1 through FIG. 11 where similar reference characters denote corresponding features consistently throughout the figures, there are shown preferred embodiments, and these embodiments are described in the context of the following exemplary system and/or method.
FIG. 1 illustrates a block diagram representation of a network architecture of a Variable Pitch Propeller (VPP) system 100 for managing operational conditions of an aircraft (not shown in FIG. 1), in accordance with some embodiments of the present disclosure. The aircraft may include, but is not limited to, Unmanned Aerial vehicles (UAVs), Remotely Piloted Aerial Vehicle (RPAV), Uncrewed Aerial Vehicle (UCAV), quadcopters (four rotors), hexa-copters (six rotors), or octocopters (eight rotors), multi-copter, Vertical Take-Off, and Landing (VTOL) drone, Heli quad, Hybrid Multirotor, folding-arm quadcopter, heavy-lift multirotor, micro multirotor, and the like. According to FIG. 1 the VPP system 100 includes actuator units 102-1, 102-2, 102-3, …. 102-N (individually referred to as the actuator unit 102 and collectively referred to as the plurality of actuator units 102), and auxiliary actuator units 104-1, 104-2, 104-3, …. 104-N (individually referred to as the auxiliary actuator unit 104 and collectively referred to as the plurality of auxiliary actuator units 104), sensors 106-1, 106-2, 106-3, …..., 106-N (individually referred to as the sensor 106 and collectively referred to as the sensors 106), a control unit 108, and a remote-control unit 110.
The remote-control unit 110 may be associated with one or more users, and communicatively coupled to the control unit 108 via a communication network (not shown in FIG. 1). In an embodiment the remote-control unit 110 may include, but is not limited to, a handheld transmitter/controller, a dedicated drone remote-controller, a First-person view (FPV) goggles or glasses, a motion controller, a voice control-based controller, a laptop computer, a desktop computer, a tablet computer, a phablet, a smartphone, a wearable device, an Augmented/Virtual Reality (AR/VR) device, a metaverse-based device, and the like. Further, the communication network may be a wired network or a wireless network. The remote-control unit 110 may also be connected to server (not shown in FIG. 1) for performing, but not limited to, remote monitoring, firmware updates, data analysis, and the like. This connection allows for real-time tracking of, but not limited to, a location, flight parameters, and battery status, ability to remotely adjust settings and configurations of the aircraft, and the like. Additionally, the server can facilitate the distribution of firmware updates to ensure a software of the aircraft remains up to date with the latest features and security patches. Furthermore, the server can aggregate data collected from multiple aircrafts for analysis, providing valuable insights into performance trends, usage patterns, and potential areas for improvement. For example, the server may be at least one of, but is not limited to, a central server, a cloud server, a remote server, a rake server, an on-premises server, and the like. Further, the remote-control unit 110 may be communicatively coupled to the database (not shown in FIG. 1), via the communication network. The database may include, but is not limited to, battery data, battery parameters data, battery characteristics data, State of Health (SoH) data, actuator data, rotor data, any other data, and combinations thereof. The database may be any kind of databases/repositories such as, but are not limited to, relational database, dedicated database, dynamic database, monetized database, scalable database, cloud database, distributed database, any other database, and combination thereof.
The one or more sensors 106 may include, but not limited to, voltage measuring sensors, a current measuring sensors, ultrasonic sensors, torque measuring sensors, angle measuring sensors, radar, optical flow sensors, gas sensors, load cells, pressure sensors, temperature sensors, vibration sensors, proximity sensors, humidity sensors, force sensors, gyroscopic sensors, accelerometers, infrared sensors, sonar sensors, optical sensors, laser sensors, microphones, motion sensors, tilt sensors, a Global Positioning System (GPS), Inertial Measurement Units (IMUs), barometers, magnetometers, a Light Detection and Ranging (LiDAR), Cameras (such as RGB, thermal, multispectral, hyperspectral), combination thereof, and the like.
Further, the remote-control unit 110 may be associated with, but not limited to, a user, an individual, an administrator, a vendor, a technician, a worker, s security personal, a surveillance personal, a specialist, a healthcare worker, an instructor, a farmer, a builder, an event manager, an environment monitor, a supervisor, a team, an entity, an organization, a company, a facility, a robot, any other user, and combination thereof. The entities, the organization, and the facility may include, but are not limited to, a hospital, a healthcare facility, an agricultural land, a security premises, a building premises, a boarder security organization, an event management, an exercise facility, a laboratory facility, an e-commerce company, an agricultural land, an environment monitoring organization, a merchant organization, an airline company, a hotel booking company, a company, an outlet, a manufacturing unit, an enterprise, an organization, an educational institution, a secured facility, a warehouse facility, a supply chain facility, any other facility and the like. The remote-control unit 110 may be used to provide input and/or receive output to/from the VPP system 100, and/or to the database, respectively. The remote-control unit 110 may present to the user one or more user interfaces for the user to interact with the VPP system 100 and/or to the database for aircraft operational conditions managing need. The remote-control unit 110 may be at least one of, an electrical, an electronic, an electromechanical, and a computing device. The electronic device may include, but is not limited to, a mobile device, a smartphone, a personal digital assistant (PDA), a tablet computer, a phablet computer, a wearable computing device, a virtual reality / augmented reality (VR/AR) device, Metaverse based devices, a laptop, a desktop, a server, and the like.
Further, the VPP system 100 may be implemented by way of a single device or a combination of multiple devices that may be operatively connected or networked together. The VPP system 100 may be implemented in hardware or a suitable combination of hardware and software. The VPP system 100 includes the control unit 108. The control unit 108 includes one or more hardware processor(s) 112, and a memory 114. The memory 114 may include a plurality of modules 116. The VPP system 100 may be a hardware device including the hardware processor 112 executing machine-readable program instructions for managing operational conditions of an aircraft. Execution of the machine-readable program instructions by the hardware processor 112 may enable the VPP system 100 to manage operational conditions of an aircraft. The “hardware” may comprise a combination of discrete components, an integrated circuit, an application-specific integrated circuit, a field-programmable gate array, a digital signal processor, or other suitable hardware. The “software” may comprise one or more objects, agents, threads, lines of code, subroutines, separate software applications, two or more lines of code, or other suitable software structures operating in one or more software applications or on one or more processors.
The one or more hardware processors 112 may include, for example, microprocessors, microcomputers, microcontrollers, digital signal processors, central processing units, state machines, logic circuits, and/or any devices that manipulate data or signals based on operational instructions. Among other capabilities, hardware processor 112 may fetch and execute computer-readable instructions in the memory 114 operationally coupled with the control unit 108 for performing tasks such as data processing, input/output processing, and/or any other functions. Any reference to a task in the present disclosure may refer to an operation being or that may be performed on data.
Though few components and subsystems are disclosed in FIG. 1, there may be additional components and subsystems which is not shown, such as, but not limited to, frames, landing gears, studs, motors, propellers, Electronic Speed Controllers (ESCs), flight controllers, batteries, charging ports, radio transmitter and receivers, gimbals, propeller guards, payload mounting systems, communication system, auxiliary components, GPS module, telemetry systems, onboard computers, Ground Control Station (GCS), antenna systems, Parachute Recovery System, Thermal Management System (TMS), redundancy system, autopilot system, Collision Avoidance Sensors (CAS), Communication Relay System, Emergency Locator Transmitter (ELT), Modular Payload System (MPS), emergency management components, image capturing devices, sensors, any other components/devices, and combination thereof. The person skilled in the art should not be limiting the components/subsystems shown in FIG. 1.
Those of ordinary skilled in the art will appreciate that the hardware depicted in FIG. 1 may vary for particular implementations. For example, other peripheral devices such as an optical disk drive and the like, local area network (LAN), wide area network (WAN), wireless (e.g., wireless-fidelity (Wi-Fi)) adapter, graphics adapter, disk controller, input/output (I/O) adapter also may be used in addition or place of the hardware depicted. The depicted example is provided for explanation only and is not meant to imply architectural limitations concerning the present disclosure.
Those skilled in the art will recognize that, for simplicity and clarity, the full structure and operation of all data processing systems suitable for use with the present disclosure are not being depicted or described herein. Instead, only so much of the VPP system 100 as is unique to the present disclosure or necessary for an understanding of the present disclosure is depicted and described. The remainder of the construction and operation of the VPP system 100 may conform to any of the various current implementations and practices that were known in the art.
In an embodiment, the Variable Pitch Propeller (VPP) system 100 may include the plurality of actuator units 102. The plurality of actuator units 102 may include a plurality of variable-pitch propeller (VPP) blades (not shown in FIG. 1). The VPP blades includes one or more cambered air foils and rotates in axial-direction. The one or more cambered air foils includes a high drag coefficient at a zero lift angles, and generates required torque at zero-thrust. The required torque generated by the plurality of VPP blades at the zero-thrust may be based on the drag coefficient of the one or more cambered air foils at the zero coefficient of lift angle, for controlling an yaw angle of the aircraft. Further, the VPP blades are spaced apart in circumferential-direction, in which each of the plurality of VPP blades is rotatable through a plurality of propeller blade angles corresponding to respective variable pitch axes each extending in radial direction.
In an embodiment, the plurality of actuator units 102 may include a plurality of foldable arms (not shown in FIG. 1). The plurality of foldable arms includes one or more connecting links, coupled to a proximal end of each of the plurality of VPP blades. The plurality of foldable arms are configured to control the plurality of propeller blade angles corresponding to the respective variable pitch axes.
In an embodiment, the plurality of actuator units 102 may include a plurality of elongated shafts. The plurality of elongated shafts includes a proximal portion and a distal portion, in which the proximal portion of each of the plurality of elongated shafts is coupled to each of the plurality of VPP blades. Further, the distal portion of each of the plurality of elongated shafts is coupled to at least one of a landing gear and a stud (not shown in FIG. 1).
In an embodiment, the plurality of actuator units 102 may include a plurality of rotors (not shown in FIG. 1). The plurality of rotors includes Direct Current (DC) motors and/or Internal Combustion Engines (ICEs) rotatably coupled to an intermediate portion of each of the plurality of elongated shafts. Each of at the DC motors and/or the ICEs is configured to rotate each of the plurality of elongated shafts.
In an embodiment, the plurality of actuator units 102 may include a plurality of frame structures (not shown in FIG. 1). The plurality of frame structures includes a proximal portion and a distal portion. The proximal portion of each of the plurality of frame structures is mounted, via a motor mount plate structure, to at least one of the DC motors and the ICEs. Further, the distal portion of each of the plurality of frame structures is mounted to at least one of the landing gear and the stud. Each of the plurality of frame structures comprises a guided slot on an inner surface.
In an embodiment, the VPP system 100 includes the plurality of auxiliary actuator units 104 are coupled to the plurality of actuator units 102 via the plurality of frame structures. Each of the plurality of auxiliary actuator units 104 includes a servo-motor (not shown in FIG. 1) coupled to a servo-motor horn within each of the plurality of frame structures. Each of the servo-motor is configured to control, via each of the plurality of elongated shafts, the plurality of propeller blade angles corresponding to the respective variable pitch axes. The servo-motor horn may convert circular motion of the servo-motor into liner motion for each of the plurality of elongated shafts. Further, the servo-motor horn includes a servo-motor shaft and a pin coupled to an end of the servo-motor shaft. The pin may be slidably coupled within a groove for converting the circular motion of the servo-motor into the linear motion of each of the plurality of elongated shafts. Furthermore, the servo-motor horn includes the servo-motor shaft and an auxiliary link serially coupled to an end of the servo-motor shaft for converting circular motion of the servo-motor into linear motion of each of the plurality of elongated shafts. The pin slidably coupled within the groove may modify the one or more control parameters corresponding to the one or more direction control parameters and the one or more mid-flight flip maneuver parameters, and the one or more failure control parameters.
In an embodiment, the VPP system 100 includes the plurality of sensors 106 mounted in proximity to each of the plurality of actuator units 102 and each of the plurality of auxiliary actuator units 104. The plurality of sensors 106 includes, but not limited to, altitude sensors, attitude sensors, airspeed sensors, angle calculation sensors, failure detection sensors, equilibrium detection sensors, torque calculation sensors, thrust calculation sensors, a combination thereof, and the like.
In an embodiment, the VPP system 100 includes the control unit 108 communicatively coupled to each of the plurality of actuator units 102 and each of the plurality of auxiliary actuator units 104. The control unit 108 includes the processor 112 and the memory 114. The memory includes processor-executable instructions, which on execution, cause the processor 112 to perform one or more steps described herein. In an embodiment, the processor 112 may receive dynamically, operational status data corresponding to an operation of each of the plurality of actuator units 102 and each of the plurality of auxiliary actuator units 104 from each of the plurality of sensors 106.
In an embodiment, the processor 112 may receive dynamically, one or more control parameters corresponding to an operation control of the aircraft, from the remote-control unit 110 communicatively coupled to the control unit 108. The one or more control parameters includes, but are not limited to, one or more direction control parameters, one or more mid-flight flip maneuver parameters, and the like. In an embodiment, the processor 112 may analyse one or more operational parameters from the operational status data received from each of the plurality of sensors 106. Further, the processor 112 may identify one or more types of fault conditions in each of the plurality of actuator units 102, and each of the plurality of auxiliary actuator units 104, based on the analysed one or more operational parameters. In an embodiment, the processor 112 may determine one or more failure control parameters for each of the plurality of actuator units 102 and each of the plurality of auxiliary actuator units 104, based on the identified the one or more types of fault conditions, using the NN-based technique.
In an embodiment, the processor 112 may control at least one of a stability parameter, an attitude parameter, and an equilibrium parameter of each of the plurality of actuator units 102 and each of the plurality of auxiliary actuator units 104, based on the determined one or more failure control parameters. The controlling is performed by varying at least one of the plurality of propeller blade angles corresponding to respective variable pitch axes, a thrust and a torque, and the like. In an embodiment, the processor 112 may manage one or more operational conditions of the aircraft based on controlling at least one of the stability parameter, the attitude parameter, the equilibrium parameter, and the received, from the remote-control unit, one or more control parameters corresponding to the operational control of the aircraft.
In an embodiment, the VPP system 100 further includes a stand-off tubular structure (not shown in FIG. 1) of a pre-defined length between the one or more connecting links of each of the plurality of foldable arms and the DC motor and/or ICEs. The stand-off tubular structure may generate a static variable-pitch angle for each of the plurality of VPP blades. The static variable-pitch angle MAY BE based on the pre-defined length of the stand-off tubular structure. Further, the rotation of plurality of VPP blades generates the pitch-down moment, forcing down the one or more connecting links and compressing the stand-off tubular structure. Additionally, the stand-off tubular structure restricts the movement of the plurality of VPP blades during forcing down of the one or more connecting links, to generate the static variable-pitch angle.
In an embodiment, the plurality of actuator units 102 further includes a zero-recoil mount unit (not shown in FIG. 1). The zero-recoil mount unit may include a recoil mass configured to a control recoil force. Further, the zero-recoil mount unit may include a base mount coupled to the recoil mass. The recoil force may be transmitted to the base mount through at least one of a spring mechanism and a damper mechanism. Furthermore, the zero-recoil mount unit may include the plurality of actuator units coupled to the base mount. The plurality of variable-pitch propeller blades may generate thrust. The thrust generated by the plurality of actuator units may be utilized to dynamically neutralize the recoil force, for stabilizing the zero-recoil mount unit. In an embodiment, the aircraft further inlcudes a plurality of struts (not shown in FIG. 1) to stabilize vibrations of the plurality of actuator units 102.
FIG. 2 illustrates a block diagram representation of a proposed control unit 108 such as those shown in FIG. 1, capable of managing operational conditions of an aircraft, in accordance with some embodiments of the present disclosure. The control unit 108 may also function as a computer-implemented system. The control unit 108 includes the one or more hardware processors 112, the memory 114, and a storage unit 204. The one or more hardware processors 112, the memory 114, and the storage unit 204 are communicatively coupled through a system bus 202 or any similar mechanism. The memory 114 includes a plurality of modules 116 in the form of programmable instructions executable by the one or more hardware processors 112.
In an embodiment, the plurality of modules 116 may include a status and parametric data receiving module 206, an operational parameter analysing module 208, a type of fault condition identifying module 210, a failure control parameter determining module 212, a stability parameter controlling module 214, and an operation condition managing module 216.
The one or more hardware processors 112, as used herein, means any type of computational circuit, such as, but not limited to, a microprocessor unit, microcontroller, complex instruction set computing exceptionally long processor unit, reduced instruction set computing microprocessor unit, very long instruction word microprocessor unit, explicitly parallel instruction computing microprocessor unit, graphics processing unit, digital signal processing unit, or any other type of processing circuit. The one or more hardware processors 112 may also include embedded controllers, such as generic or programmable logic devices or arrays, application-specific integrated circuits, single-chip computers, and the like.
The memory 114 may be a non-transitory volatile memory and a non-volatile memory. The memory 114 may be coupled to communicate with the one or more hardware processors 112, such as being a computer-readable storage medium. The one or more hardware processors 112 may execute machine-readable instructions and/or source code stored in the memory 114. A variety of machine-readable instructions may be stored in and accessed from the memory 114. The memory 114 may include any suitable elements for storing data and machine-readable instructions, such as read-only memory, random access memory, erasable programmable read-only memory, electrically erasable programmable read-only memory, a hard drive, a removable media drive for handling compact disks, digital video disks, diskettes, magnetic tape cartridges, memory cards, and the like. In the present embodiment, the memory 114 includes the plurality of modules 116 stored in the form of machine-readable instructions on any of the above-mentioned storage media and may be in communication with and executed by the one or more hardware processors 112.
The storage unit 204 may be a cloud storage or a repository such as those shown in FIG. 1. The storage unit 204 may store, but is not limited to, battery data, battery parameters data, battery characteristics data, State of Health (SoH) data, actuator data, rotor data, any other data, and combinations thereof. The storage unit 204 may be any kind of storage, memory, databases/repositories such as, but are not limited to, relational database, dedicated database, dynamic database, monetized database, scalable database, cloud database, distributed database, any other database, and combination thereof.
In an embodiment, the status and parametric data receiving module 206 may receive dynamically, operational status data corresponding to an operation of each of the plurality of actuator units 102 and each of the plurality of auxiliary actuator units 104 associated with the VPP system 100, from each of a plurality of sensors 106.
In an embodiment, the status and parametric data receiving module 206 may receive dynamically, one or more control parameters corresponding to an operation control of the aircraft, from the remote-control unit 110 communicatively coupled to the control unit 108. The one or more control parameters includes, but are not limited to, one or more direction control parameters, one or more mid-flight flip maneuver parameters, and the like. In an embodiment, the operational parameter analysing module 208 may analyse one or more operational parameters from the operational status data received from each of the plurality of sensors 106. Further, the type of fault condition identifying module 210 may identify one or more types of fault conditions in each of the plurality of actuator units 102, and each of the plurality of auxiliary actuator units 104, based on the analysed one or more operational parameters. In an embodiment, the failure control parameter determining module 212 may determine one or more failure control parameters for each of the plurality of actuator units 102 and each of the plurality of auxiliary actuator units 104, based on the identified the one or more types of fault conditions, using the NN-based technique.
In an embodiment, the stability parameter controlling module 214 may control at least one of a stability parameter, an attitude parameter, and an equilibrium parameter of each of the plurality of actuator units 102 and each of the plurality of auxiliary actuator units 104, based on the determined one or more failure control parameters. The controlling is performed by varying at least one of the plurality of propeller blade angles corresponding to respective variable pitch axes, a thrust and a torque, and the like. In an embodiment, the operation condition managing module 216 may manage one or more operational conditions of the aircraft based on controlling at least one of the stability parameter, the attitude parameter, the equilibrium parameter, and the received, from the remote-control unit, one or more control parameters corresponding to the operational control of the aircraft.
In an embodiment, for managing one or more operational conditions based on the received one or more control parameters corresponding to the operation control of the aircraft, the status and parametric data receiving module 206 may receive during a mid-flight of the aircraft, the one or more control parameters corresponding to the one or more mid-flight flip maneuver parameters, from the remote-control unit 110. Further, the operation condition managing module 216 may modify, in the mid-flight, the plurality of propeller blade angles corresponding to the respective variable pitch axes to a negative value to generate a negative thrust of each of the plurality of VPP blades. Further, the stability parameter controlling module 214 may control at least one of a stability parameter, an attitude parameter, an equilibrium parameter, and the negative thrust of each of the plurality of actuator units 102 and each of the plurality of auxiliary actuator units 104, based on the modified the plurality of propeller blade angles corresponding to the respective variable pitch axes to the negative value.
In an embodiment, for controlling at least one of the stability parameter, the attitude parameter, and the equilibrium parameter of each of the plurality of actuator units 102 and each of the plurality of auxiliary actuator units 104, based on the determined one or more failure control parameters, the processor 112 may determine thrust forces generated by each of the plurality of actuator units 102. Further, the processor 112 may identify a first set of actuator units 102 from the plurality of actuator units 102 being in a working condition and a second set of actuator units from the plurality of actuator units 102 being in a fault condition, upon determining the thrust forces generated by each of the plurality of actuator units 102.
In an embodiment, the processor 112 may generate, using the NN-based technique, the thrust forces in the identified first set of actuator units being in the working condition and opposite to the second set of actuator units being in the fault condition, to a half of a pre-determined weight of the aircraft. This is to manage a vertical equilibrium corresponding to the equilibrium parameter. The thrust forces in the identified first set of actuator units balance a weight of the aircraft.
In an embodiment, the processor 112 may negate the thrust forces in the identified second set of actuator units being in the fault condition and opposite to first set of actuator units being in the working condition. Further, the processor 112 may maintain, using the NN-based technique, a torque balance corresponding to a pre-defined axis based on controlling a first torque value generated by the first set of actuator units and a second torque value generated by the second set of actuator units, for a rotational stability corresponding to the stability parameter. Further, generating the thrust forces and maintaining the torque balance includes controlling an attitude corresponding to the attitude parameter of the aircraft.
FIG. 3A illustrates a front view of a schematic diagram representation of a Variable Pitch Propeller (VPP) technique of the actuator unit 102 in the aircraft, in accordance with some embodiments of the present disclosure. FIG. 3A depicts a comparison between a conventional VPP system (on the left) and the proposed VPP system (on the right). In the proposed VPP system 100, the auxiliary actuator unit 104 may be used per rotor to control the propeller pitch angle precisely of the VPP blades 302. The auxiliary actuator unit 104 may be a servo-motor310, which is in addition to the other actuator(s) (e.g., actuator unit 102) that rotates the VPP blades 302. On multirotor systems, either a centralized source such as an Internal Combustion Engine ((ICEs) may be used to spin all the propellers at the same Revolution Per Minute (RPM), or every propeller may be rotated by a separate source such as an electric motor, for example a Brushless Direct Current (BLDC) motor 308.
The VPP technique may include one Degree of Freedom (DOF) and be mechanically as simple as possible. The servo-motor310 may precisely rotate the input link 306, which is connected to a series of subsequent links 304-1, 304-2 and 304-3 ending in the output link to which the VPP blades 302 are fixed. This results in a planar closed-loop (parallel) mechanism. For clarity, in FIG. 3A, only a single propeller blade is shown. Multiple propeller blades can be mounted on an individual VPP mechanism/technique based on a requirement. The VPP technique controls the collective pitch of the propeller. This means all the VPP blades 302 may have a same pitch angle at any given time.
In an embodiment, an elongated shaft 306 may be constrained to move vertically. In practice, the elongated shaft 306 may pass through the hollow shaft of the rotating motor 308 as shown in FIG. 3A (right). A ball bearing is fixed to the top end of an elongated shaft 306. Further, a foldable arm 304-1 (e.g., link 2) may be fixed on the rotating outer race of the bearing. The Link 2 may be connected to a foldable arm 304-2 (e.g., link 3) by a revolute joint. The Link 3 may be further connected to another foldable arm 304-3 (e.g., Link 4) by another revolute joint. The link 4 may be grounded on the other end. In practice, the link 4 304-3 may be fixed on an outside of the hollow shaft of the rotating BLDC motor 308. Therefore, link 1 306 may remain stationary with respect to the ground, and Links 2, 3, and 4 (304-1, 304-2, and 304-3 may rotate at the RPM of the BLDC motor 308. The VPP blades 302 may be rigidly connected to link 4 304-3. Depending on the number of VPP blades 302, the link 2 304-1 may be connected to multiple chains of links similar to links 3 304-2, and 4 304-3. To avoid imbalance of the aircraft, the links 304-1, 304-2, and 304-3 may have the same dimensions and should be arranged symmetrically in the top plane. For example, for ‘n’ VPP blades 302, there may be ‘n’ links similar to Link 3 304-2 and ‘n’ links similar to link 4 304-3.
To change the propeller pitch angle, the servo-motor310 may need to control the vertical motion of link 1 306. Currently, there is no provision for vertical motion in VPP-based conventional systems. The embodiments herein provide a pin 314 and a slot 316 mechanism to convert servo-motor rotation to a linear motion of the link 1 306. Other mechanisms may also be used such as serial 2R manipulators. As shown in FIG. 3A (right), a servo-horn 312 (e.g., crank) may be connected to a servo-motor shaft, and a pin 314 may be attached to the other end of the servo-horn 312. The pin 314 may include a sliding fit in the slot 316. The slot 316 may further rigidly connected to link 1 306. The overall mechanism may be similar to a Revolute-Prismatic-Revolute-Revolute (RPRR) variant of a 4-bar chain, with one active joint input variable ? (i.e., servo-motor input shown in FIG. 3A) and the output being the propeller pitch angle.
FIG. 3B illustrates a front view of a schematic diagram representation of a scenario of first kind of singularity in a Variable Pitch Propeller (VPP) technique of the actuator unit 102 in the aircraft, in accordance with some embodiments of the present disclosure. According to conventionally VPP mechanism/techniques or, in general, any closed-loop kinematic chain, different kinds of singularities may be encountered within the workspace. The singularities can be classified into three groups such as first singularity, second singularity, and third singularity. In the first singularity, referred to as a dwell, the concerned link may be at a dead point. In the VPP mechanism/technique, the dwell may correspond to a singularity in which the propeller pitch angle not changing despite finite servo-motor rotation. In the second singularity, the VPP mechanism gain one or more DOFs. Here, the passive joints may move with the actuators locked. Therefore, in VPP mechanism the pitch angle may change while the servo-motor horn 312 may be fixed. The third singularity combines the first singularity and the second singularity and may occur for special link parameters. During the operation of the VPP mechanism, the singularities may not be desired. The first singularity and second singularity are shown in FIG. 3B and FIG. 3C, respectively.
FIG. 3C illustrates a front view of a schematic diagram representation of a scenario of second kind of singularity in a Variable Pitch Propeller (VPP) technique of the actuator unit 102 in the aircraft, in accordance with some embodiments of the present disclosure. The singularities may be avoided in the proposed VPP technique/mechanism. The first singularity may be avoided by increasing the servo-horn length (r) as shown in FIG. 3A. By increasing ‘r’, the link 1 306 may be enabled to move vertically by a certain amount with lesser deflection in ‘?’. The first singularity may not occur if, ‘?’ does not reach 90 degrees. As the propeller stalls at higher pitch angles (for example, 20-25 degrees), by increasing ‘r’, the pitch angle range may be covered with lesser values of ‘?’ without reaching 90 degrees. The second singularity arises when the link 4 304-3 and link 3 304-2 may become parallel. To avoid second singularity when the link 4 304-3 and link 3 304-2 may become parallel, the operating propeller pitch angle workspace ‘Y_0’ may be increased within a pre-defined angle, as shown in FIG. 3A.
FIG. 4 illustrates a block diagram of the actuator unit 102 with the landing gear 406, or a stud 406 associated with the Variable Pitch Propeller (VPP) system 100 of the aircraft, in accordance with some embodiments of the present disclosure. Each of the plurality of auxiliary actuator units 104 includes a servo-motor 310 coupled to the servo-motor horn 312, within each of a plurality of frame structures 402. Further, the BLDC motor 308 may be mounted on a motor mount plate 404. For example, the conventional VPP mechanisms may suffer from very high vibrations. For example, the vibrations may arise due to a moment of propeller imbalance and loosely supported mechanisms. The embodiments herein reduce vibration amplitude due to the propeller imbalance moment is reduced as the propeller blades rotation plane is closer to the support. The guide 408 may acts as the support for link 1 306, suppressing the lateral vibrations significantly. The guide 408 may act as the landing gear 406 or stud 406. This eliminates the need for separate landing gear.
FIG. 5 illustrates a front view of a stand-off 502 associated with the actuator unit 102, in accordance with some embodiments of the present disclosure. The stand-off 502 may be used for changing the propeller pitch in mid-flight by controlling the servo-motor310. However, there are some real-time applications where mid-flight propeller pitch change may not be necessary. For example, if the same aircraft is expected to take off at sea level as well as high altitude (increasing the propeller pitch angle at higher altitudes is power-efficient), adding extra servos for the “one-time change “ may be redundant. Embodiments herein may provide the VPP system 100 even for a static VPP mechanism. Here, the propeller pitch may be changed once the propellers stop spinning. This can be enabled by introducing the stand-off 502 between the link 2 304-1 and the elongated shaft 306 (also referred herein as link 1 306), as shown in FIG. 5. The length of the stand-off 502 may decide the pitch angle of the propeller. When the propeller rotates, the stand-off 502 may generate the pitch-down moment, forcing down the link 2 304-1. As the link 2 304-1 may try to compress the stand-off 502, the movement may be restricted due to stiffness of the stand-off 502 and maintain the propeller pitch angle.
FIG. 6 illustrates an example aircraft 600 with Heli-quad prototype including actuator units 102 and struts 602, in accordance with some embodiments of the present disclosure. The proposed VPP technique/mechanism may be used in for example, a quadcopter (e.g., Heli quad), for each actuator unit 102 of the quadcopter (or in general any multirotor) to enable maneuvers that are beyond the dynamics of traditional Fixed-Pitch-Propeller (FPP) quadcopters. The VPP mechanism with the pin 314 and the slot 316 module may be implemented on a custom-built Heli quad to enable mid-flight maneuvers/flipping and an actuator Fault-Tolerant-Control (FTC).
For example, the Heli quad may perform mid-flight maneuvers/flips due to an ability of the proposed VPP mechanism to generate the thrust force in both directions (up and down). Changing the propeller pitch angle to a negative value may enable the propeller blades to generate negative thrust. The propeller pitch angle may be commanded to a negative value mid-flight to commence flipping. After flipping, the Heli quad may sustain the inverted flight, which implies that the Heli quad may be controlled similar to regular upright state. Flipping the Heli quad may include in applications such as, but not limited to, mapping an area above an airframe (usually the mapping payloads such as cameras are attached beneath the airframe), reducing vibrations and noise by eliminating the aerodynamic interference between propeller wake and airframe, in a defense-related evasion maneuvers, and the like.
In another example, Heli quad may include an ability to control full attitude even under the complete failure of an actuator 102. Complete failure may be defined as the inability of the actuator 102 to produce any thrust or torque. This scenario may occur in case of a completely blown-off propeller or a fault in the BLDC motor 308. The complete failure complicates the stability and full attitude control authority of the quadcopter. Under complete failure of one actuator, reduced attitude control for quadcopters requires sacrificing of control over the yaw angle because of the non-existence of an equilibrium point. In reduced attitude control conditions, position references may be still tracked at with requirements of very high yaw rate requirements. Hence, such a quadcopter may not be usable for safety-critical payloads (passenger-carrying multirotor). Full attitude (with yaw angle) control for traditional quadcopters (using fixed-pitch propellers) under a complete failure of a single actuator may not be dynamically possible in conventional VPP systems. In yet another example, static equilibrium or hover may be possible in a conventional fixed-pitch quadcopter when the vehicle weight is balanced by the collective thrust produced by the four propellers. The torque generated by two opposite working propellers is nullified by other sets of propellers. Complete failure of one actuator induces asymmetry in the design. In such conditions, in a conventional fixed-pitch quadcopter may maintain hover equilibrium.
Embodiments herein may provide proposed aircraft 600 of for example, Heli-quad design, which may qualitatively achieve hover equilibrium with only three working actuators. Without any loss in generality, as an example, consider that the actuator 4 in on the Heli-quad shown in FIG. 6 may not be working. In these conditions, to maintain hover equilibrium, the following equations may need to be satisfied.
T1 + T3 = mg ….equation 1
T1 = T3 =mg/2 ….equation 2
T2 = 0 ….equation 3
t_2 = t_1 + t_3 ….equation 4

In the above equations 1, 2, 3, and 4, the variable T_i and t_i may be a thrust and a torque, respectively, produced by an i^th propeller respectively. Further, the variable ‘mg’ may be a weight of the Heli quad. If, the total thrust-to-weight ratio of the Heli quad is greater than two, then it is possible to satisfy equation 1 and equation 2. The use of a variable pitch actuator may qualitatively satisfy conditions of equation 3 and equation 4, because it can produce zero thrust and non-zero torque simultaneously. The zero thrust and non-zero torque is achieved by setting the propeller pitch angle near zero degrees. However, the propeller aerodynamics may play a pivotal role in the feasibility of satisfying the above conditions.
FIG. 7A illustrates a perspective view of a plurality of variable-pitch propeller (VPP) blades associated with the actuator unit 102 of the VPP system 100, in accordance with some embodiments of the present disclosure. The use of a VPP actuator in the VPP system 100 may be to neutralize impulse/shock-like reaction forces. The VPP actuators may have a much faster response time compared to the standard Fixed Pitch Propeller (FPP) actuators. The standard FPP actuators achieve a desired thrust force by changing the motor rotation speed (RPM). Changing the motor RPM may not be an instantaneous action as the motor has to work against the propeller torque. This takes some finite time to achieve the desired RPM, thus reducing the bandwidth of a conventional VPP system. Lesser bandwidth hampers an ability of the conventional VPP system to move quickly/aggressively.
As shown in FIG. 7A, the propeller torque (t) acts opposite to a direction of rotation (?) of the BLDC motor 308. The larger the RPM, the larger may be the thrust (T) and torque. On the standard FPP actuators to increase the thrust the RPM has to be increased resulting in a slower response due to opposing motor torque. However, in the VPP actuators the propeller pitch angle may also be controlled in addition to the regular RPM. Changing the thrust by changing the propeller pitch angle provides a faster response due to the absence of opposing (impeding) forces of the proposed VPP system 100.
FIG. 7B illustrates a side view of a zero-recoil mount unit 700 associated with a variable-pitch propeller (VPP) blades in the actuator unit 102, in accordance with some embodiments of the present disclosure. The higher bandwidth of VPP actuators 702 or the actuator unit 102 resulting from respective faster response characteristic may be used to neutralize the undesired impulse or shock-like forces produced by a recoiling mass 704 such as, but not limited to, a riveting gun, jackhammer, machine gun, and the like. An arrangement similar to FIG. 7B may be used to nullify the recoil force and to effectively achieve a zero-recoil force on the base 706 (e.g., mount).
The recoil force acts on the recoil mass 704 (for example, riveting run), and the recoil force may be transmitted through a spring/damper mechanism 708 to the base 706 mount. The VPP actuator 702 may be rigidly fixed on the base 706. The thrust generated by the VPP actuator 702 may be used to quickly neutralize the recoil force. The VPP actuator 702 may essentially nullify the recoil force. However, note that the nature of F_VPP may not be the same as the nature of F_recoil, shown in FIG. 7. The spring/mass damper 708 may be used in between to change the characteristics of the transmitted force. For example, a dynamic spring damper 708 may be used to transmit a much lower amplitude with a longer duration sinusoid-like force to the base mount 706, or by implementing constant-force springs, a constant force throughout can be transmitted to the base mount 706. This force is neutralized by the thrust generated by the VPP actuator (F_VPP) 702. Such a setup can be used on, but not limited to, mobile vehicles with mounted recoil mass (the light-weight vehicle may not withstand high recoil forces), wearable robotic exoskeletons, robotic mine/tunnel digging using high recoil-producing jackhammers, pneumatic and hydraulic impact tools, and the like.
FIG. 7C illustrates a schematic diagram and a graph diagram representation of comparison between typical symmetric and cambered airfoil associated with a plurality of variable-pitch propeller (VPP) blades 302, in accordance with some embodiments of the present disclosure. The conventional multi-rotors with the VPP may often use symmetric airfoils in the propeller blades. Symmetric airfoils are efficient in producing lift in both directions, however, have a very low drag coefficient. The torque produced by the propeller blades may be directly proportional to the drag coefficient of the airfoils This makes satisfying above equation 4, infeasible due to the upper limit on the rotor RPM. The very high RPM (> 8000) requirement causes intense vibrations on the multi-rotor. The proposed VPP system in the Heli quad may solve this problem by using cambered airfoils in the blade. Cambered airfoils may have a very high drag coefficient at zero lift angles of attack which in turn can generate sufficient torque at zero-thrust to satisfy equation 4. The comparison between a typical symmetric and cambered airfoil is shown in graph of FIG. 7C.
To enable full-attitude control one actuator has to generate zero thrust and finite torque (in this case actuator 2 of FIG. 6). The torque generated by the propeller blade at zero thrust depends heavily on the drag coefficient (C_d) of the airfoil at zero coefficient of lift (C_l). As seen from graph of FIG. 7C, the Cd_(cl=0) for cambered airfoil is much higher (typically 4-5 times) than its symmetrical airfoil counterparts. This difference allows the cambered airfoil propeller to generate sufficient torque to enable yaw control.
FIG. 8 illustrates a block diagram representation of input and output commands for control allocation technique of autopilot in an aircraft, in accordance with some embodiments of the present disclosure. Consider, a Neural-Network (NN)-based control allocation technique deployed in the control unit 108 as an autopilot algorithm (flight-controller) for the Heli quad. While designing the autopilot, the extremely nonlinear relationship between the desired thrust and actuator commands (propeller pitch and RPM) should be handled with care. A complete autopilot flow sequence 800 for manual mode or automatic mode is shown in FIG. 8. The following aspects describe the working of the control loop.
The upright or inverted state of the Heli quad may be determined by a Boolean variable s(t). s(t)=0 for upright and s(t)=1 for inverted flight. Switching the values mid-flight may cause the Heli quad to flip 180 degrees and maintain the commanded attitude. Usually, the pilot may use the remote-control unit 110 such as, for example, a hand-held Ground-Control-Station (GCS) to switch s(t). The bounded roll (f_cmd), pitch (?_cmd), and yaw rate (?_cmd ) ?) values are commanded as the reference for the attitude controller to track. Usually, in the manual mode of flying these commands are mapped from the joysticks on the GCS. A separate Fault-Detection and Isolation (FDI) module may be running parallelly to detect the faults. Based on the fault, FDI may output the parameter µ. This parameter µ ? {0, 1, 2, 3, 4} represents the index of the completely failed actuator. µ = 0 means all the actuators are working properly.
The control unit 108 may include a control allocation module. The control allocation module takes the desired thrust and torque as the input and outputs the required actuator commands (propeller pitch and RPM). In the standard FPP multirotor, there is only one actuator command (RPM), and there is a simple quadratic relationship between it and the thrust/torque. This quadratic equation can be easily implemented in a conventional autopilot software. However, for the VPP system 100, there may be no analytical relationship between the actuator commands and thrust/torque. Therefore, a conventional VPP autopilots make use of iterative methods in the control allocation. These methods are shown to work well in the simulations; however, their implementation onboard the autopilot hardware may be challenging due to limited computing power and uncertainty related to the propeller aerodynamic model. There has been no experimental verification of the state-of-the-art control allocation methods.
Embodiments herein may include a control allocation algorithm to enable the use of Neural-Networks (NN) to approximate the relationship between desired thrust/torque and actuator commands. The NN architecture may be of any type with any number of hidden layers and using any activation function. The NN architecture may include, but not limited to, Convolutional Neural Networks (CNNs), Recurrent Neural Networks (RNNs), Long Short-Term Memory (LSTM) Networks, Deep Reinforcement Learning (DRL), Generative Adversarial Networks (GANs), autoencoders, transfer learning, attention mechanisms, Feedforward Neural Networks (FNNs), Radial Basis Function Networks (RBFNs), Self-Organizing Maps (SOMs), Restricted Boltzmann Machines (RBMs), Deep Belief Networks (DBNs), Echo State Networks (ESNs), Growing Neural Gas (GNG), Hopfield Networks, Boltzmann Machines, Modular Neural Networks (MNN), Spiking Neural Networks (SNNs), Liquid State Machines (LSMs), and the like. The data used to train the NN may be obtained by running the simulations or by conducting experiments with a single actuator on the load cell. Once the data is gathered, the NN may be trained using standard back-propagation algorithms. The use of pre-trained NN’s in the autopilot software may be computationally lightweight, efficient, and robust.
FIG. 9 illustrates a graph diagram representation 900 of a step input tracking performance comparison between a Fixed-Pitch-Propeller (FPPs)-based actuator and a Variable Pitch Propeller (VPP)-based actuator, in accordance with some embodiments of the present disclosure. The comparison between FPP actuator response time and VPP actuator response time for step input tracking is shown in a graph 900 of FIG. 9. In the graph 900, the RPM may be changed by changing voltage. Changing only the pitch angle may significantly be faster than changing only the RPM. Changing both provides the best result with minimal overshoot.
FIG. 10 illustrates an example Neural Network (NN) architecture 1000 associated with the control unit 108, for generating desired thrust or torque commands for the actuator units 102, in accordance with some embodiments of the present disclosure. For example, the NNs may be used to obtain the static map between the desired thrust/torque to actuator commands. For example, a processor subroutine outputs the desired thrust and torque that the actuators 102 have to generate. The desired thrust and torque values are input to the NN. The NN outputs the actuator commands (propeller pitch angles and motor RPMs). The NN can be trained either on the simulation data or the experimentally collected values. Further, the NN architecture 1000 may be a single hidden layer or multi-layer perceptron with any number of neurons. The activation function of the neuron may be a known procedure. There could be multiple NNs working simultaneously. In FIG. 10, the input to the NN architecture 1000 may be the desired thrust value and the desired pitch angle. Output may be the commanded RPM. In general, the permutations of desired thrust, desired torque, pitch angle, and motor RPM may be input and at least one of them may be the output.
FIG. 11 illustrates a flow chart depicting a method 1100 for managing operational conditions of the aircraft 600 using the Variable Pitch Propeller (VPP) system 100, in accordance with some embodiments of the present disclosure.
In an embodiment, the method 1100 may include receiving dynamically, by the processor 112, operational status data corresponding to an operation of each of the plurality of actuator units 102 and each of the plurality of auxiliary actuator units 104 associated with the Variable Pitch Propeller (VPP) system 100, from each of a plurality of sensors 106.
In an embodiment, the method 1100 may include receiving dynamically, by the processor 112, one or more control parameters corresponding to an operation control of the aircraft 600, from the remote-control unit 110. The one or more control parameters includes, but not limited to, one or more direction control parameters, one or more mid-flight flip maneuver parameters, and the like.
In an embodiment, the method 1100 may include analysing, by the processor 112, one or more operational parameters from the operational status data received from each of the plurality of sensors 106.
In an embodiment, the method 1100 may include identifying, by the processor 112, one or more types of fault conditions in each of the plurality of actuator units and each of the plurality of auxiliary actuator units, based on the analysed one or more operational parameters.
In an embodiment, the method 1100 may include determining, by the processor 112, one or more failure control parameters for each of the plurality of actuator units and each of the plurality of auxiliary actuator units, based on the identified one or more types of fault conditions, using the NN-based technique.
In an embodiment, the method 1100 may include controlling, by the processor 112, at least one of a stability parameter, an attitude parameter, and an equilibrium parameter of each of the plurality of actuator units and each of the plurality of auxiliary actuator units, based on the determined one or more failure control parameters, by varying at least one of the plurality of propeller blade angles corresponding to respective variable pitch axes, a thrust and a torque.
In an embodiment, the method 1100 may include managing, by the processor 112, one or more operational conditions of the aircraft based on controlling at least one of the stability parameter, the attitude parameter, the equilibrium parameter, and the received, from the remote-control unit, one or more control parameters corresponding to the operational control of the aircraft.
The order in which the method 1100 is described is not intended to be construed as a limitation, and any number of the described method blocks may be combined or otherwise performed in any order to implement the method 1100 or an alternate method. Additionally, individual blocks may be deleted from the method 1100 without departing from the spirit and scope of the ongoing description. Furthermore, the method 1100 may be implemented in any suitable hardware, software, firmware, or a combination thereof, that exists in the related art or that is later developed. The method 1100 describes, without limitation, the implementation of the VPP system 100 and/or control unit 108. A person of skill in the art will understand that method 1100 may be modified appropriately for implementation in various manners without departing from the scope and spirit of the ongoing description.
Various embodiments of the present disclosure provide a Variable Pitch Propeller (VPP) system and a method for managing operational conditions of an aircraft. The VPP mechanism may be seamlessly integrated into various aircrafts such as drone architectures, including multirotor, VTOL systems, and fixed-wing airplanes, offering adaptability across different drone platforms. By allowing dynamic adjustment of propeller pitch mid-flight, the VPP mechanism optimizes power usage, enabling drones to compensate for dynamic environmental conditions such as wind, thus maximizing overall efficiency. Further, static adjustment of propeller pitch ensures maximum effectiveness at different atmospheric densities, facilitating efficient take-offs across varying altitudes without compromising performance. Precise control over propeller pitch enables rapid thrust adjustments, facilitating agile and acrobatic maneuvers that are essential for drones executing aggressive flight maneuvers. The aircraft ability to flip mid-flight enables inverted flight, expanding its utility for applications requiring access to areas both above and below the aircraft, such as tunnel or cave inspections, roof-ceiling mapping, and stealth operations. The aircraft design allows to maintain full-attitude control even in the event of actuator failure, ensuring safety in critical scenarios. This feature is invaluable for passenger-carrying vehicles, cargo drones, defense applications, and operations in cluttered environments where reliability is paramount.
Further, the VPP mechanism includes integration of pin-slot or 2R module. The incorporation of a pin-slot or 2R module with the vertical control rod ensures a smooth, singularity-free, and linear response, addressing issues prevalent in existing VPP mechanisms. Furthermore, housing a portion of the VPP mechanism within the landing gear reduces vibrations by providing additional support, while simultaneously decreasing overall system weight, offering a unique solution not found in conventional system. Additionally, an introduction of a standoff between the top link and BLDC motor shaft facilitates static propeller pitch changes without requiring an extra actuator, representing a novel approach to pitch adjustment in VPP mechanisms.
Additionally, the VPP system utilizes cambered air foil propellers, enabling full-attitude control, including yaw, even in the event of complete actuator failure, a feature unparalleled in prior art quadcopters. Unlike conventional designs, the aircraft can transition from upright to inverted mid-flight, expanding its operational versatility and applicability for various aerial tasks. Further, the utilization of Neural-Network-based autopilot software ensures lightweight and robust control over the entire flight envelope, a novel approach not previously employed in VPP systems.
The written description describes the subject matter herein to enable any person skilled in the art to make and use the embodiments. The scope of the subject matter embodiments is defined by the claims and may include other modifications that occur to those skilled in the art. Such other modifications are intended to be within the scope of the claims if they have similar elements that do not differ from the literal language of the claims or if they include equivalent elements with insubstantial differences from the literal language of the claims.
A description of an embodiment with several components in communication with each other does not imply that all such components are required. On the contrary, a variety of optional components are described to illustrate the wide variety of possible embodiments of the invention. When a single device or article is described herein, it will be apparent that more than one device/article (whether they cooperate) may be used in place of a single device/article. Similarly, where more than one device or article is described herein (whether or not they cooperate), it will be apparent that a single device/article may be used in place of the more than one device or article or a different number of devices/articles may be used instead of the shown number of devices or programs. The functionality and/or the features of a device may be alternatively embodied by one or more other devices which are not explicitly described as having such functionality/features. Thus, other embodiments of the invention need not include the device itself.
The illustrated steps are set out to explain the exemplary embodiments shown, and it should be anticipated that ongoing technological development will change the manner in which particular functions are performed. These examples are presented herein for purposes of illustration, and not limitation. Further, the boundaries of the functional building blocks have been arbitrarily defined herein for the convenience of the description. Alternative boundaries can be defined so long as the specified functions and relationships thereof are appropriately performed. Alternatives (including equivalents, extensions, variations, deviations, etc., of those described herein) will be apparent to persons skilled in the relevant art(s) based on the teachings contained herein. Such alternatives fall within the scope and spirit of the disclosed embodiments. Also, the words “comprising”, “having”, “containing”, and “including”, and other similar forms are intended to be equivalent in meaning and be open-ended in that an item or items following any one of these words is not meant to be an exhaustive listing of such item or items, or meant to be limited to only the listed item or items. It must also be noted that as used herein and in the appended claims, the singular forms “a”, “an”, and “the” include plural references unless the context clearly dictates otherwise.
Finally, the language used in the specification has been principally selected for readability and instructional purposes, and it may not have been selected to delineate or circumscribe the inventive subject matter. It is therefore intended that the scope of the invention be limited not by this detailed description, but rather by any claims that issue on an application based here on. Accordingly, the embodiments of the present invention are intended to be illustrative, but not limiting, of the scope of the invention, which is set forth in the following claims.

, Claims:PATENT CLAIMS
We claim:
1. A Variable Pitch Propeller (VPP) system (100) for managing operational conditions of an aircraft (600), the VPP system (100) comprising:
a plurality of actuator units (102) comprising:
a plurality of variable-pitch propeller (VPP) blades (302), comprising one or more cambered air foils, configured to rotate in axial-direction and spaced apart in circumferential-direction, wherein each of the plurality of VPP blades (302) is rotatable through a plurality of propeller blade angles corresponding to respective variable pitch axes each extending in radial direction;
a plurality of foldable arms, comprising one or more connecting links (304), coupled to a proximal end of each of the plurality of VPP blades (302), wherein the plurality of foldable arms are configured to control the plurality of propeller blade angles corresponding to the respective variable pitch axes;
a plurality of elongated shafts (306) comprising a proximal portion and a distal portion, wherein the proximal portion of each of the plurality of elongated shafts (306) is coupled to each of the plurality of VPP blades (302), and wherein the distal portion of each of the plurality of elongated shafts (306) is coupled to at least one of a landing gear (406) and a stud (406);
a plurality of rotors comprising at least one of Direct Current (DC) motors (308) and Internal Combustion Engines (ICEs) (308) rotatably coupled to an intermediate portion of each of the plurality of elongated shafts (306), wherein each of at least one of the DC motors (308) and the ICEs (308) is configured to rotate each of the plurality of elongated shafts (306); and
a plurality of frame structures (402)comprising a proximal portion and a distal portion, wherein the proximal portion of each of the plurality of frame structures (402)is mounted, via a motor mount plate structure (404), to each of at least one of the DC motors (308) and the ICEs (308), and the distal portion of each of the plurality of frame structures (402)is mounted to at least one of the landing gear (406) and the stud (406), wherein each of the plurality of frame structures (402)comprises a guided slot on an inner surface;
a plurality of auxiliary actuator units (104) are coupled to the plurality of actuator units (102) via the plurality of frame structures, wherein each of the plurality of auxiliary actuator units (104) comprising:
a servo-motor (310) coupled to a servo-motor horn (312) within each of the plurality of frame structures, configured to control, via each of the plurality of elongated shafts (306), the plurality of propeller blade angles corresponding to the respective variable pitch axes, wherein the servo-motor horn (312) is configured to convert circular motion of the servo-motor (310) into liner motion for each of the plurality of elongated shafts (306);
a plurality of sensors (106) mounted in proximity to each of the plurality of actuator units (102) and each of the plurality of auxiliary actuator units (104); and
a control unit (108) communicatively coupled to each of the plurality of actuator units (102) and each of the plurality of auxiliary actuator units (104), wherein the control unit (108) comprising:
a processor (112) and a memory (114), wherein the memory (114) comprises processor-executable instructions, which on execution, cause the processor (112) to:
receive, dynamically,
operational status data corresponding to an operation of each of the plurality of actuator units (102) and each of the plurality of auxiliary actuator units (104), from each of the plurality of sensors (106), and
one or more control parameters corresponding to an operation control of an aircraft (600), from a remote-control unit (110) communicatively coupled to the control unit (108), wherein the one or more control parameters comprises one or more direction control parameters and one or more mid-flight flip maneuver parameters;
analyse one or more operational parameters from the operational status data received from each of the plurality of sensors (106);
identify one or more types of fault conditions in each of the plurality of actuator units (102) and each of the plurality of auxiliary actuator units (104), based on the analysed one or more operational parameters;
determine one or more failure control parameters for each of the plurality of actuator units (102) and each of the plurality of auxiliary actuator units (104), based on the identified the one or more types of fault conditions, using the NN-based technique;
control at least one of a stability parameter, an attitude parameter, and an equilibrium parameter of each of the plurality of actuator units (102) and each of the plurality of auxiliary actuator units (104), based on the determined one or more failure control parameters, by varying at least one of the plurality of propeller blade angles corresponding to respective variable pitch axes, a thrust and a torque; and
manage one or more operational conditions of the aircraft (600) based on controlling at least one of the stability parameter, the attitude parameter, the equilibrium parameter, and the received, from the remote-control unit (110), one or more control parameters corresponding to the operational control of the aircraft (600).

2. The VPP system (100) as claimed in claim 1, wherein for managing one or more operational conditions based on the received one or more control parameters corresponding to the operation control of the aircraft (600), the processor (112) is further configured to:
receive, during a mid-flight of the aircraft (600), the one or more control parameters corresponding to the one or more mid-flight flip maneuver parameters, from the remote-control unit (110);
modify, in the mid-flight, the plurality of propeller blade angles corresponding to the respective variable pitch axes to a negative value to generate a negative thrust of each of the plurality of VPP blades (302); and
control at least one of a stability parameter, an attitude parameter, an equilibrium parameter, and the negative thrust of each of the plurality of actuator units (102) and each of the plurality of auxiliary actuator units (104), based on the modified the plurality of propeller blade angles corresponding to the respective variable pitch axes to the negative value.

3. The VPP system (100) as claimed in claim 1, wherein for controlling at least one of the stability parameter, the attitude parameter, and the equilibrium parameter of each of the plurality of actuator units (102) and each of the plurality of auxiliary actuator units (104), based on the determined one or more failure control parameters, the processor (112) is further configured to:
determine thrust forces generated by each of the plurality of actuator units (102);
identify a first set of actuator units from the plurality of actuator units (102) being in a working condition and a second set of actuator units from the plurality of actuator units (102) being in a fault condition, upon determining the thrust forces generated by each of the plurality of actuator units (102);
generate, using the NN-based technique, the thrust forces in the identified first set of actuator units being in the working condition and opposite to the second set of actuator units being in the fault condition, to a half of a pre-determined weight of the aircraft (600), to manage a vertical equilibrium corresponding to the equilibrium parameter, wherein the thrust forces in the identified first set of actuator units balance a weight of the aircraft (600);
negate the thrust forces in the identified second set of actuator units being in the fault condition and opposite to first set of actuator units being in the working condition; and
maintain, using the NN-based technique, a torque balance corresponding to a pre-defined axis based on controlling a first torque value generated by the first set of actuator units and a second torque value generated by the second set of actuator units, for a rotational stability corresponding to the stability parameter, wherein generating the thrust forces and maintaining the torque balance comprises controlling an attitude corresponding to the attitude parameter of the aircraft (600).

4. The VPP system (100) as claimed in claim 1, further comprises a stand-off tubular structure (502) of a pre-defined length between the one or more connecting links (304) of each of the plurality of foldable arms and at least one of the DC motors (308) and the ICEs (308).

5. The VPP system (100) as claimed in claim 4, wherein the stand-off tubular structure (502) is configured to:

generate a static variable-pitch angle for each of the plurality of VPP blades (302), wherein the static variable-pitch angle is based on the pre-defined length of the stand-off tubular structure (502),
wherein, the rotation of plurality of VPP blades (302) generates the pitch-down moment, forcing down the one or more connecting links (304) and compressing the stand-off tubular structure (502), and wherein the stand-off tubular structure (502) restricts the movement of the plurality of VPP blades (302) during forcing down of the one or more connecting links (304), to generate the static variable-pitch angle.

6. The VPP system (100) as claimed in claim 1, wherein the plurality of actuator units (102) further comprises:
a zero-recoil mount unit, comprising:
a recoil mass (704) configured to a control recoil force;
a base mount (706) coupled to the recoil mass (704), wherein the recoil force is transmitted to the base mount (706) through at least one of a spring mechanism (708) and a damper mechanism (708); and
the plurality of actuator units (102) coupled to the base mount (706),
wherein the plurality of Variable-Pitch Propeller (VPP) blades is configured to generate thrust, and wherein the thrust generated by the plurality of actuator units (102) is utilized to dynamically neutralize the recoil force, for stabilizing the zero-recoil mount unit.

7. The VPP system (100) as claimed in claim 1, wherein the one or more cambered air foils comprises a high drag coefficient at a zero lift angles, and generates required torque at zero-thrust, wherein the required torque generated by the plurality of VPP blades (302) at the zero-thrust is based on the drag coefficient of the one or more cambered air foils at the zero coefficient of lift angle, for controlling an yaw angle of the aircraft (600)

8. The VPP system (100) as claimed in claim 1, wherein the aircraft (600) further comprises a plurality of struts to stabilize vibrations of the plurality of actuator units (102).

9. The VPP system (100) as claimed in claim 1, wherein the plurality of sensors (106) comprises at least one of an altitude sensor, an attitude sensor, an airspeed sensor, an angle calculation sensor, a failure detection sensor, an equilibrium detection sensor, a torque calculation sensor, and a thrust calculation sensor.

10. The VPP system (100) as claimed in claim 1, wherein the servo-motor horn (312) comprises a servo-motor shaft and a pin (314) coupled to an end of the servo-motor shaft, wherein the pin (314) is slidably coupled within a groove for converting the circular motion of the servo-motor (310) into the linear motion of each of the plurality of elongated shafts (306).

11. The VPP system (100) as claimed in claim 1, wherein the servo-motor horn (312) comprises the servo-motor shaft and an auxiliary link serially coupled to an end of the servo-motor shaft for converting circular motion of the servo-motor (310) into linear motion of each of the plurality of elongated shafts (306).

12. The VPP system (100) as claimed in claim 1, wherein the pin (314) slidably coupled within the groove is configured to modify the one or more control parameters corresponding to the one or more direction control parameters and the one or more mid-flight flip maneuver parameters, and the one or more failure control parameters.

13. A method for managing operational conditions of an aircraft (600) using a Variable Pitch Propeller (VPP) system (100), the method comprising:
receiving dynamically, by a processor (112),
operational status data corresponding to an operation of each of a plurality of actuator units (102) and each of a plurality of auxiliary actuator units (104) associated with a Variable Pitch Propeller (VPP) system (100), from each of a plurality of sensors (106), and
one or more control parameters corresponding to an operation control of an aircraft (600), from a remote-control unit (110), wherein the one or more control parameters comprises one or more direction control parameters and one or more mid-flight flip maneuver parameters;
analysing, by the processor (112), one or more operational parameters from the operational status data received from each of the plurality of sensors (106);
identifying, by the processor (112), one or more types of fault conditions in each of the plurality of actuator units (102) and each of the plurality of auxiliary actuator units (104), based on the analysed one or more operational parameters;
determining, by the processor (112), one or more failure control parameters for each of the plurality of actuator units (102) and each of the plurality of auxiliary actuator units (104), based on the identified one or more types of fault conditions, using the NN-based technique;
controlling, by the processor (112), at least one of a stability parameter, an attitude parameter, and an equilibrium parameter of each of the plurality of actuator units (102) and each of the plurality of auxiliary actuator units (104), based on the determined one or more failure control parameters, by varying at least one of the plurality of propeller blade angles corresponding to respective variable pitch axes, a thrust and a torque; and
managing, by the processor (112), one or more operational conditions of the aircraft (600) based on controlling at least one of the stability parameter, the attitude parameter, the equilibrium parameter, and the received, from the remote-control unit (110), one or more control parameters corresponding to the operational control of the aircraft (600).

14. The method as claimed in claim 13, wherein managing one or more operational conditions based on the received one or more control parameters corresponding to the operation control of the aircraft (600), further comprises:
receiving, by the processor (112), during a mid-flight of the aircraft (600), the one or more control parameters corresponding to the one or more mid-flight flip maneuver parameters, from the remote-control unit (110);
modifying, by the processor (112), in the mid-flight, the plurality of propeller blade angles corresponding to the respective variable pitch axes to a negative value to generate a negative thrust of each of the plurality of VPP blades (302); and
controlling, by the processor (112), at least one of a stability parameter, an attitude parameter, an equilibrium parameter, and the negative thrust of each of the plurality of actuator units (102) and each of the plurality of auxiliary actuator units (104), based on the modified the plurality of propeller blade angles corresponding to the respective variable pitch axes to the negative value.

15. The method as claimed in claim 13, wherein controlling at least one of the stability parameter, the attitude parameter, and the equilibrium parameter of each of the plurality of actuator units (102) and each of the plurality of auxiliary actuator units (104), based on the determined one or more failure control parameters, further comprises:
determining, by the processor (112), thrust forces generated by each of the plurality of actuator units (102);
identifying, by the processor (112), a first set of actuator units from the plurality of actuator units (102) being in a working condition and a second set of actuator units from the plurality of actuator units (102) being in a fault condition, upon determining the thrust forces generated by each of the plurality of actuator units (102);
generating, by the processor (112), using the NN-based technique, the thrust forces in the identified first set of actuator units being in the working condition and opposite to the second set of actuator units being in the fault condition, to a half of a pre-determined weight of the aircraft (600), to manage a vertical equilibrium corresponding to the equilibrium parameter, wherein the thrust forces in the identified first set of actuator units balance a weight of the aircraft (600);
negating, by the processor (112), the thrust forces in the identified second set of actuator units being in the fault condition and opposite to first set of actuator units being in the working condition; and
maintaining, by the processor (112), using the NN-based technique, a torque balance corresponding to a pre-defined axis based on controlling a first torque value generated by the first set of actuator units and a second torque value generated by the second set of actuator units, for a rotational stability corresponding to the stability parameter, wherein generating the thrust forces and maintaining the torque balance comprises controlling an attitude corresponding to the attitude parameter of the aircraft (600).
Dated this 21st day of March 2024

Sanath M V (IN/PA 5004)
Prasa IP
Agent for the Applicant