Claims:

1. A system for a remotely operated underwater vehicle (ROV) for inspection, the system comprising:
a safety and distribution box connected with a main power supply source for power distribution to the remotely operated underwater vehicle, a Control Station, a Tether Management System and to any auxiliary device connected with the ROV;
a buoyant umbilical tether cable connected to the remotely operated underwater vehicle (ROV);
a control unit for controlling and operating the ROV; and
a tether cable management system interfaced with said control unit for winding and unwinding the buoyant umbilical cable;
the safety and distribution box generate a high voltage DC current and transmit to the ROV so that the ROV is enable to operate at predetermined maximum length of the umbilical cable.

2. The system for operating a remotely operated underwater vehicleas claimed in claim 1, wherein system comprisesan electronic system havinga processing unit, a communication unit, a networking unit, embedded units, sensors and payloads.

3. The system for operating a remotely operated underwater vehicle as claimed in claim 1, wherein the system includes a support system comprises of :
the safety and distribution box to convert the input AC current to high voltage DC current and distribute said DC current to the remotely operated underwater vehicle, control station, tether management system and to other auxiliary devices,
setting up of communication link with the remotely operated underwater vehicle for controlling the ROV remotely, and
transferring data between the ROV and control station and post processing of inspection data, as recorded by the remotely operated underwater vehicle, in the control station.

4. The system for operating a remotely operated underwater vehicle as claimed in claim 1 or claim 3, wherein the safety and distribution box having:
an isolation transformer connected with the AC main power supply;
high voltage DC power converters for generating the high voltage DC and supplying it to the remotely operated underwater vehicle;and
a line filter connected inline to the input of power converters to attenuate noise frequencies.

5. The system for operating a remotely operated underwater vehicle as claimed in claim 1, wherein the control station comprises a web based user interface having a vision module for displaying, recording, streaming real-time vision of plurality of cameras mounted on the remotely operated underwater vehicle and displaying the data of the vision module on a user device that include screen or a mobile device, a computer or tablet.

6. The system for operating a remotely operated underwater vehicle as claimed in claim 1, wherein the DC voltage output is 400 Volts or higher.

7. The system for operating a remotely operated underwater vehicle as claimed in claim 1, wherein the predetermined length of the umbilical cable is 1000 metres or higher.

8. A remotely operated underwater vehicle comprising:
a frame;
a buoyancy unit mounted on top of the frame;
a cylindrical hull mounted inside the frame;
a hexagonal hull assembly mounted co-axially in front of the cylindrical hull;
eight brushless thrusters on the frame;
a plurality of enclosures mounted on the frame;
a network adaptor and communication unit adapted inside the cylindrical hull for connecting the remotely operated underwater vehicle to the control station via communication cable;
a navigation module;
micro-controller units;
a computing unit;
a plurality of sensors mounted on the frame;
a plurality of cameras mounted inside the enclosures and connected with the network adapter;
an illumination system having plurality of lights mounted inside the enclosures;
an altimeter mounted on the frame and connected with the cylindrical hull;
a plurality of attachment mounts for mounting payloads; and
wherein a thrust-to-weight ratio of said ROV is configurable in range greater than 0.5.

9. The remotely operated underwater vehicle as claimed in claim 8, wherein, the eight thrusters include a top sway thruster, a bottom sway thruster, a fore heave thruster, a rear heave thruster, two port surge thrusters, and two starboard surge thrusters.

10. The remotely operated underwater vehicle as claimed in claim 8 or claim 9, wherein sway, heave and surge thrusters are mounted symmetrically.

11. The remotely operated underwater vehicle as claimed in claim 8, wherein the remotely operated underwater vehicle comprises power regulators to convert a high voltage DC current to a lower voltage DC current and supply it to the electronics, communication units, vision units, illumination units, sensors and payloads.

12. The remotely operated underwater vehicle as claimed in claim 8, wherein the remotely operated underwater vehicle comprises a plurality of cooling fans to agitate the air inside hull and transfer heat from power converters and conductors to hull via either convection or conduction.

13. The remotely operated underwater vehicle as claimed in claim 8, wherein said plurality of payloads include LASERs, GPS, at least one high pressure jet - cleaning unit, at least one spot cleaning unit, at least one ultrasonic thickness measurement probes, at least one cathodic Potential measurement probe, at least one acoustic device, 2D & 3D SONARs sensors, hydrographic and radiation sensors.

14. The remotely operated underwater vehicle as claimed in claim 8, wherein the ROV comprises a plurality of heat sinks are in contact with hull surface and cooling fans facilitate heat dissipation from power converters, thereby maintaining thermal performance of power converters.

15. The remotely operated underwater vehicle as claimed in claim 8, wherein the remotely operated underwater vehicle comprises a protective bumper mounted at the top of the frame.

16. The remotely operated underwater vehicle as claimed in claim 8, wherein the remotely operated underwater vehicle comprises multiple lifting points and multiple tether attachment points.

17. The remotely operated underwater vehicle as claimed in claim 8, wherein vertical thrusters are placed symmetric to the lateral axis and diagonally opposite to each other.

18. The remotely operated underwater vehicle as claimed in claim 8, wherein thrusters mounted symmetric to the longitudinal axis provide independent control for surge and yaw motions.

19. The remotely operated underwater vehicle as claimed in claim 8, wherein sway and roll motions of the remotely operated underwater vehicle are controlled using thrusters mounted symmetric to the transverse axis.

20. The remotely operated underwater vehicle as claimed in claim 8, wherein the camera enclosures consist of a transparent membrane which enables capturing 360 degrees field-of-view during pan & tilt control.

21. The remotely operated underwater vehicle as claimed in claim 8, wherein the hulls, vision system units, propulsion units, illumination units, sensors and payloads are mounted symmetrically on the frame.
, Description:FORM 2

THE PATENTS ACT, 1970
(39 of 1970)

&

THE PATENTS RULES, 2003

COMPLETE SPECIFICATION
[See section 10, Rule 13]

A SYSTEM FOR A REMOTELY OPERATED UNDERWATER VEHICLE FOR INSPECTION

PLANYS TECHNOLOGIES PRIVATE LIMITED, AN INDIAN COMPANY HAVING ADDRESS, NO. 5, JAYA NAGAR EXTENSION, BALAJI NAGAR MAIN ROAD, G.K. AVENUE, PUZHUTHIVAKKAM, CHENNAI – 600091, TAMIL NADU, INDIA

THE FOLLOWING SPECIFICATION PARTICULARLY DESCRIBES THE INVENTION AND THE MANNER IN WHICH IT IS TO BE PERFORMED.

FIELD OF THE INVENTION
The present invention relates to a remotely operated underwater vehicle and more particularly to a system for a remotely operated underwater vehicle for inspection.
BACKGROUND OF THE INVENTION
Human endeavours have witnessed the developments not limited to exploration of technologies at top of the water but also extended to underwater applications. Keeping pace with the growth of the technology, underwater vehicles/robots were also developed which has brought the underwater world an inch closer to the mankind.
The advancement in these vehicles have enabled to explore areas of water bodies which are practically impossible or perilous for a human diver to reach. As their deployment and usage increased over the years, these underwater robots started catering to different applications, reduced the dependency on human divers, mitigated the risks involved in underwater operation and improved the reliability and accuracy of data collected by manifolds.
They can be broadly categorized into Autonomous Underwater Vehicles (AUVs) and Remotely Operated Underwater Vehicles (ROVs). The former can be pre-programmed to function without any human input and the latter is controlled by a remote human operator, sending commands over an umbilical cable.
ROVs are deployed underwater for a wide range of applications, which essentially include:
i. Visual and Non-destructive techniques (NDT) based inspection of immersed underwater structures;
ii. Ship hull, ship propeller, rudder, and ballast tank inspection;
iii. Inspection of oil tank and water tank floors;
iv. Cleaning of marine and bio-fouling growth from ship hull and underwater structures;
v. Measurement of structural thickness and cathodic protection potentials on offshore structures;
vi. Determination of flooding in structural members of offshore platforms through acoustic techniques;
vii. Inspection of radiation leak in Nuclear Power Plants;
viii. Rapid defect detection and repair of interoceanic pipelines/cable lines;
ix. Bathymetric surveys using SONARs to study seabed topography; and
x. Hydrographic surveys to characterize water properties such as conductivity, temperature, pH, dissolved oxygen (DO), turbidity and oxidation-reduction potential.
An ROV is required to perform the above-said applications at varying depths, while combating simultaneously with environmental forces with respect to wind, waves, swell and currents. Further, the ROVs are required to navigate in such conditions to reach the target and perform inspection using sensors and payloads. However, it has also been observed that the existing observation class ROVs system are incapable to support very long tether lengths or in other words due to the limitations of the existing technologies, the ROVs have been found to be failed in manoeuvring at larger distance and depth from the control station.
It has been observed that mostly conventional observation class ROVs are powered by single-phase AC current, provided to the ROV via. tether cable. The single phase AC voltage generally ranges between 220-240 volts at source and the same is transmitted from the source to the ROV.
Due to the electrical resistance provided by the tether cable, there are certain voltage drops and thus the voltage received at the ROV decreases gradually with the increased length of the umbilical cable.As the power consumption by the ROV increases, the resistance provided by the tether cable increases further which again reduces the voltage received at the ROV. The decreased input voltage is insufficient to power the components of the ROV as required and limiting the ROV’s application to a certain length of umbilical cable. Due to increased resistance and power transmission losses, the ROV of the observation class category with power rating in the range of 2 – 2.5 kW fails to support beyond 150-200 metre tether length from the control station. As the input AC voltage decreases, the power convertors fail to supply the required power to the thrusters and other components of the ROV. Therefore, the ROV is unable to operate at its peak specification.
It has also been observed that the existing observation class ROVs are incapable in performing multiple applications at a time and thus different categories of ROVs are required to perform different applications which consequently increase the costs of the operation.
Further, due to the existing design and configuration including the placement of the components therein, the light weight observation class ROVs face difficulty while operating whenever the sea state is more than two. Whereas the ROVs which are configured to operate in high depth and high sea states have been found to be extremely heavy and bulky in size which consequently affect the mobility, deployment and retrieval of ROVs.
It has also been observed that existing observation class ROVs face problems while operating in underwater locations wherein the entry points are narrow, due to their bulky size. Moreover, it has been observed that the existing design and configuration of ROVs lack provisions for mounting any additional sensor or payload as per the requirement of the operation.
Therefore, the object of the present invention is to solve one or more of the aforesaid issue.

SUMMARY
In accordance with the present invention, a system for a remotely operated underwater vehicle (ROV) for inspection is provided. The system comprising: a safety and distribution box connected with a main power supply source for power distribution to the remotely operated underwater vehicle, a Control Station, a Tether Management System and to any auxiliary device connected with the ROV; a buoyant umbilical tether cable connected to the remotely operated underwater vehicle (ROV); a control unit for controlling and operating the ROV; and a tether cable management system interfaced with said control unit for winding and unwinding the buoyant umbilical cable; the safety and distribution box generate a high voltage DC current and transmit to the ROV so that the ROV is enable to operate at predetermined maximum length of the umbilical cable. The system comprises an electronic system having a processing unit, a communication unit, a networking unit, embedded units, sensors and payloads.

In accordance with an embodiment of the present invention, the system includes a support system comprises of: the safety and distribution box to convert the input AC current to high voltage DC current and distribute said DC current to the remotely operated underwater vehicle, control station, tether management system and to other auxiliary devices, setting up of communication link with the remotely operated underwater vehicle for controlling the ROV remotely, and transferring data between the ROV and control station and post processing of inspection data, as recorded by the remotely operated underwater vehicle, in the control station.

In accordance with an embodiment of the present invention, the safety and distribution box is having: an isolation transformer connected with the AC main power supply; high voltage DC power converters for generating the high voltage DC and supplying it to the remotely operated underwater vehicle; and a line filter connected inline to the input of power converters to attenuate noise frequencies.

In accordance with the present invention, the control station comprises a web based user interface having a vision module for displaying, recording, streaming real-time vision of plurality of cameras mounted on the remotely operated underwater vehicle and displaying the data of the vision module on a user device that include screen or a mobile device, a computer or tablet.

In accordance with an embodiment of the present invention, the DC voltage output is 400 Volts or higher. Further, the predetermined length of the umbilical cable is 1000 metres or higher.

In accordance with another embodiment of the present invention, a remotely operated underwater vehicle is provided. The remotely operated underwater vehicle comprising: a frame; a buoyancy unit mounted on top of the frame; a cylindrical hull mounted inside the frame; a hexagonal hull assembly mounted co-axially in front of the cylindrical hull; eight brushless thrusters on the frame; a plurality of enclosures mounted on the frame; a network adaptor and communication unit adapted inside the cylindrical hull for connecting the remotely operated underwater vehicle to the control station via communication cable; a navigation module; micro-controller units; a computing unit; a plurality of sensors mounted on the frame; a plurality of cameras mounted inside the enclosures and connected with the network adapter; an illumination system having plurality of lights mounted inside the enclosures; an altimeter mounted on the frame and connected with the cylindrical hull; a plurality of attachment mounts for mounting payloads; and wherein a thrust-to-weight ratio of said ROV is configurable in range greater than 0.5. The eight thrusters include a top sway thruster, a bottom sway thruster, a fore heave thruster, a rear heave thruster, two port surge thrusters, and two starboard surge thrusters.

In accordance with an embodiment of the present invention, the sway, heave and surge thrusters are mounted symmetrically. The remotely operated underwater vehicle comprises power regulators to convert a high voltage DC current to a lower voltage DC current and supply it to the electronics, communication units, vision units, illumination units, sensors and payloads.

In accordance with an embodiment of the present invention, the remotely operated underwater vehicle comprises a plurality of cooling fans to agitate the air inside hull and transfer heat from power converters and conductors to hull via either convection or conduction.

In accordance with an embodiment of the present invention, said plurality of payloads include LASERs, GPS, at least one high pressure jet - cleaning unit, at least one spot cleaning unit, at least one ultrasonic thickness measurement probes, at least one cathodic Potential measurement probe, at least one acoustic device, 2D & 3D SONARs sensors, hydrographic and radiation sensors.

In accordance with an embodiment of the present invention, the ROV comprises a plurality of heat sinks which are in contact with hull surface and cooling fans facilitate heat dissipation from power converters, thereby maintaining thermal performance of power converters. Further, the remotely operated underwater vehicle comprises a protective bumper mounted at the top of the frame.

In accordance with an embodiment of the present invention, the remotely operated underwater vehicle comprises multiple lifting points and multiple tether attachment points. The vertical thrusters are placed symmetric to the lateral axis and diagonally opposite to each other.

In accordance with an embodiment of the present invention, the thrusters mounted symmetric to the longitudinal axis provide independent control for surge and yaw motions.

In accordance with an embodiment of the present invention, the sway and roll motions of the remotely operated underwater vehicle are controlled using thrusters mounted symmetric to the transverse axis.

In accordance with an embodiment of the present invention, the camera enclosures of the remotely operated underwater vehicle consist of a transparent membrane which enables capturing 360 degrees field-of-view during pan & tilt control.

In accordance with an embodiment of the present invention, the hulls, vision system units, propulsion units, illumination units, sensors and payloads are mounted symmetrically on the frame.
BRIEF DESCRIPTION OF THE DRAWINGS
Reference will be made to embodiments of the invention which may be illustrated in the accompanying figure(s). These figure(s) are intended to be illustrative and not limiting. Although the invention is generally described in the context of these embodiments, it should be understood that it is not intended to limit the scope of the invention to these particular embodiments.
FIG. 1 shows an isometric view of the remotely operated underwater vehicle (ROV) in accordance with an embodiment of the present invention.
FIG. 2 shows another isometric view of the remotely operated underwater vehicle (ROV) in accordance with an embodiment of the present invention.
FIG. 3 shows the configuration of the thrusters of the remotely operated underwater vehicle (ROV) along its axis in accordance with an embodiment of the present invention
FIG. 4 illustrates the block diagram of the configuration of power supply to the components of the system for operating remotely operated underwater vehicle in accordance with an embodiment of the present invention.
FIG. 5 illustrates the block diagram of the system of the present invention in accordance with an embodiment of the present invention.
FIG. 6 illustrates the block diagram of the safety and distribution box in accordance with an embodiment of the present invention.
FIG. 7 shows a comparison graph of receiving end voltage of the 3kW power rated ROV between single-phase AC and high voltage DC transmissions in accordance with a working experiment and a suitable tether cable.
DETAILED DESCRIPTION OF THE INVENTION
The following description with reference to the accompanying drawings is provided to assist in a comprehensive understanding of exemplary embodiments of the invention as defined by the claims and their equivalents. It includes various specific details to assist in that understanding but these are to be regarded as merely exemplary. Accordingly, those of ordinary skill in the art will recognize that various changes and modifications of the embodiments described herein can be made without departing from the scope and spirit of the invention. In addition, descriptions of well-known functions and constructions are omitted for clarity and conciseness.
The terms and words used in the following description and claims are not limited to the bibliographical meanings, but, are merely used by the inventor to enable a clear and consistent understanding of the invention. Accordingly, it should be apparent to those skilled in the art that the following description of exemplary embodiments of the present invention are provided for illustration purpose only and not for the purpose of limiting the invention as defined by the appended claims and their equivalents.
It is to be understood that the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to "a component surface" includes reference to one or more of such surfaces.
The present invention discloses a system of a remotely operated underwater vehicle, the system comprising: a safety and distribution box connected with a main power supply source generating 400 Volt DC or higher and for power distribution to the remotely operated underwater vehicle, a control station, a tether management system and to any other auxiliary device; a buoyant umbilical cable for transferring power to the remotely operated underwater vehicle and for establishing a communication link between the ROV and the control station; a control station for controlling the operation of the ROV and for assisting the user in manoeuvring the vehicle; a tether management system for winding and unwinding the buoyant umbilical cable, up to predetermined lengths of 1000m or higher.
According to the present invention, the tether management system manages the long, neutrally buoyant umbilical cable. It can be operated in both, automatic and manual modes. The tether management system consists of a slip ring of adequate power rating and communication protocol, for easy winding and un-winding of tether.

In accordance with an embodiment of the present invention, the high voltage DC current transmission to the ROV through safety and distribution box enables the vehicle to support long tether length, exceeding 1 km or more whereas the capability to pull long tether lengths and an extremely efficient thrust-to-weight ratio of the ROV, configurable in range greater than 0.5, which makes it a unique design in the Observation class of ROVs.
In accordance with the present invention, the system includes a support system comprising the safety and distribution box to convert the input AC current to high voltage DC current and distribute said DC current to the remotely operated underwater vehicle, control station, tether management system and to other auxiliary devices, setting up of communication link with the remotely operated underwater vehicle for controlling the ROV remotely, and transferring data between the ROV and control station and post processing of inspection data, as recorded by the remotely operated underwater vehicle, in the control station.
In accordance with the present invention, the remotely operated underwater vehicle is an observation class ROV which is capable to pull long tether length and is having a high thrust to weight ratio.
The present invention provides that the ROV is configured with an attitude and heading reference system (AHRS) for orientation feedback of the vehicle. The submersible pressure sensor is mounted on the ROV for depth feedback. The Altimeter is mounted on the frame for altitude feedback. The ROV consist a plurality of cameras configured with pan & tilt control, and facilitate 360 degrees field-of-view in horizontal and vertical plane and assisting the user pilot in navigation as well as underwater visual inspection.
The configuration of the present ROV allows easy integration of a wide variety of payloads, ranging from LASERs, GPS, High Pressure Jet - Cleaning unit, Spot Cleaning unit, Ultrasonic thickness measurement probes, Cathodic Potential measurement probe, acoustic devices, various 2D & 3D SONARs and different hydrographic & radiation sensors.
In accordance with the Fig. 1 of the present invention, the remotely operated underwater vehicle comprising: a frame; buoyancy foam units mounted on top of the frame; a cylindrical hullmounted inside the frame; a hexagonal hull assembly mounted co-axially in front of the cylindrical hull; eight brushless thrusters mounted on the frame; a plurality of enclosures mounted on the frame; a network adaptor and a computing unitadapted inside the cylindrical hull; a plurality of sensors mounted on the frame; a plurality of cameras mounted inside the enclosures; an illumination system having plurality of lights mounted inside the enclosures; an altimeter mounted on the frame and connected to the cylindrical hull; a plurality of attachment mounts for mounting auxiliary payloads.
The present invention discloses a remotely operated underwater vehicle comprising two watertight, metallic hulls, hexagonal and cylindrical in shape, housing power and electronic circuits respectively, as shown in figure 1 & 2. The hexagonal hull is mounted co-axially and in front of the cylindrical hull. This configuration of the hulls provides thermal isolation of electronic components of the ROVs from power converter modules. The hulls are made waterproof using O-rings, providing water-tightness up to and beyond 200 meters of depth.

Referring to the Fig. 1 & 2 of the present invention, the ROV comprises an open metal, high stiffness, lightweight, metallic frame, providing it with good hydrodynamic characteristics and capability to withstand sudden impact loads. The frame members are manufactured using high yield strength metal.

In accordance with the present invention, the system comprises a tether management system to manage the long, neutrally buoyant umbilical cable, and to supports both, automatic as well as manual operation. It consists of a slip ring of adequate power rating and communication protocol, for easy winding and un-winding of tether.

In accordance with an embodiment of the present invention, the thrusters include a top sway thruster, a bottom sway thruster, a fore heave thruster, a rear heave thruster, two port-side surge thrusters, and two starboard-side surge thrusters.

In accordance with an embodiment of the present invention, the ROV comprises a protective bumper mounted at the top of the frame.

In accordance with a non-limiting embodiment of the present invention the sway, heave and surge thrusters are mounted symmetrically. The remotely operated underwater vehicle comprises power regulators to convert a high voltage DC current to a lower voltage DC current and supply it to electronics, communication units, vision units, illumination units, sensors and payloads

In accordance with an embodiment of the present invention, the end plate consists of watertight marine connectors to facilitate waterproof connections of power input, communication, thrusters, lights, cameras, sensors and payloads with circuits inside the hull. Alongside hulls, ROV comprises of metallic and plastic enclosures for cameras and lights. Camera enclosures consist of a transparent membrane which serves the purpose of 360 degrees field-of-view during pan & tilt control. All these enclosures are water sealed using O-rings.

In accordance with an embodiment of the present invention, the hulls, vision system units, propulsion units, illumination units, sensors and payloads are mounted symmetrically on the frame.Neutrally buoyant skids have been designed for payloads to avoid disturbance to vehicle dynamics. Ease of assembly, multiple lifting points and multiple tether attachment points make it a multi-use case and highly modular design.

Referring to the Fig. 3 of the present invention, the propulsion system of the ROV comprises ofeightbrushless thrusters adaptable to all six degrees of freedom. The thrusters amounted symmetric to the longitudinal axis of the frame provide independent control for surge and yaw motions of the ROV.Thevertical thrustersmounted symmetric to the lateral axis of the frame and diagonally opposite to each other, provide heave and pitch controls in diving plane. According to the present invention, thesway and roll motions are controlled using thrusters mounted symmetric to the transverse axis. The ROV is configured with Auto-heading, auto-depth and accurate yaw, pitch and roll controls
Referring to the Fig. 4 of the present invention, the block diagram illustrates the power architecture of the system. According to an embodiment of the present invention, the ROV is configured to support universal grid, high voltage AC supply as well as high voltage DC supply. The Safety and Distribution Box of the system takes the main input and generates high voltage DC (HVDC) output via. power factor corrected rectifiers. The HVDC power is then transferred from the distribution box to the ROV over a, long length, neutrally buoyant umbilical cable. The HVDC output transferred to the ROV is then stepped down to an isolated voltage inside ROV to power thrusters whereas this voltage is further converted to other set of isolated voltages, through use of buck and boost DC-DC converters; for highly regulated, noise-free power supply to electronics, communication units, vision units, illumination units, sensors and payloads.
According to the present invention, electrical losses from power converters and high current carrying conductors generate heat inside the hull, which is dissipated to the surrounding water through principles of conduction. Physical mates with hull surface and presence of heat sinks facilitate heat dissipation from power converters. Cooling fans of the ROV agitate the air inside hull and transfer heat from conductors to hull via convection. The hull of the ROV gets cooled down by surrounding water via conduction, thus maintaining the thermal performance of converters. Further, the ROV comprises a plurality of heat sinks are in contact with hull surface and cooling fans facilitate heat dissipation from power converters, thereby maintaining thermal performance of power converters.
The electronics architecture of the embodiment of the present invention comprises of a computing unit, micro-controller units and communication unit. The functions of the micro-controller unitsof the ROV include:
i. Speed or thrust control of each thrusters
ii. Feedback and data collection from each thruster
iii. Control of Cleaning unit
iv. Feedback and data collection from power converters
v. Communication with sensors and payloads
vi. Intensity or brightness control of lights in illumination system
vii. Control of LASERs
viii. Monitoring leak status of hulls and enclosures
ix. Monitoring thermal performance of electronics inside hulls

In accordance with the present invention, the ROV is configured with various communication protocols such as but not limited to Fiber Optics, to establish a long-range communication link between ROV and Control Station. These protocols provide stable downlink & uplink bandwidth across the required umbilical length and thus facilitate 2-way transmission of videos, sensory data and joystick commands between ROV and Command Module.
In the present invention, the ROV includes anAttitude and Heading Reference System(AHRS) sensor which providesa drift free and high accuracy, orientation feedback. The ROV also includes a submersible depth sensor providing depth feedback with a very high full-scale accuracy.
According to an embodiment of thesystem of the present invention, the ROV supports Analog, RS232, RS422, RS485, USART/UART, USB and Ethernet 10/100/1000 communication modes which enables an easy interface for a large variety of payloads such as Cameras, Altimeter, 2D/3D SONARs, Ultrasonic Thickness measurement unit, Cathodic potential measurement unit, cleaning unit, GPS, hydrographic & radiation sensors, etc.
The ROV system further consists of multiple lights, having intensity exceeding 2000 lumens, which are ideal for navigating the vehicle in low lighting conditions. The intensity or brightness and colour characteristics of these lights can be controlled as per requirement of the application or the operation to be performed by the remotely operated underwater vehicle.
According to the system of the present invention, the control station includes a web-based interface for the user. The control station is having a display screen to display the real time video stream being received from all the camera units mounted at the ROV. Further, it is configured to display the data output from all the devices, sensors and the payloads adapted at the ROV. The real-time status and the video stream assist the user in navigating the ROV as per the requirement of the application.

The control station of the present invention includes a vision module for displaying, recording, streaming real-time vision of plurality of cameras mounted on navigating vehicle, a web-based user interface cockpit for displaying data of the vision module on a user device that include screen or a mobile device, or a computer or a tablet or a personal digital assistant (PDA) which assist the user in navigating the remotely operated underwater vehicle on to target surface of interest, and a dashboard for displaying input data and feedback data of the remotely operated underwater vehicle relating to control of a plurality of sensors, a plurality of payloads, a plurality of thrusters , a plurality of illumination units, enabling the user to run a quick system level check before deploying the remotely operated underwater vehicle. The control station allows the user in manoeuvring the remotely operated underwater vehicle via a user input device or joystick. All the 6 components, inclusive of vision module, device manager, mission controller, remote controller, user interface and sensor dashboard, are inter related and their data is shared using IPC (Inter Process communication) methods. The development of these components followed modular architecture. These components are dependent on plurality of hardware devices, plurality of sensors and plurality of payloads of the navigating vehicle.
.
According to an embodiment of the present invention, the control systemcomprises of a command Module for controlling the ROV. It is equipped with a high brightness, sunlight readable LCD screen which displays Cockpit and Sensor Dashboard for assisting the user pilot in manoeuvring the vehicle. The control system consists of a processing unit, communication unit, networking equipment, controller joystick, power converter and other input devices to achieve following functions:
i. Power conversion to provide power supply to all devices
ii. Setup communication link between ROV and Control Station
iii. Remote control of ROV
iv. Post processing of inspection data, as recorded by ROV
The networking equipment allocates a unique IP address to the computing unit present in ROV for communication and data transfer.
Referring to the Fig. 5 of the present invention, the system comprises of a Safety& Power Distribution Box for ensuring safety of ROV and of the personnel handling the whole system. The Safety & Power Distribution Box distributes power from main supply source to ROV, Command module, Tether Management System and any other auxiliary device. An isolation transformer, connected inline to main power input, isolates the whole ROV system from power source which ensures safety and minimizing noises in power line. According to the system of the present invention, a High voltage DC supply is generated through power converters present inside the safety and Distribution Box. A line filter connected inline to the input of power converters attenuates noise frequencies. It features short circuit, over-current, over-voltage and earth leakage protections, through use of safety devices of optimal electrical ratings.

In accordance with an embodiment of the present invention, the safety and distribution box having:an isolation transformer connected with the AC main power supply;high voltage DC power converters for generating the high voltage DC and supplying it to the remotely operated underwater vehicle; and a line filter connected inline to the input of power converters to attenuate noise frequencies.

In accordance with the present invention, the control station of the ROV is connected with an input device for controlling the vehicle. The control station is equipped with a high brightness, sunlight readable LCD screen to assist the user in operating the vehicle. The control stationconsists of processing unit, communication unit, networking equipment, controller joystick, power converter and other input devices to achieve following functions:
i. Power conversion to provide power supply to all devices
ii. Setup communication link between ROV and Control Station
iii. Remote control of ROV
iv. Post processing of inspection data, as recorded by ROV

The networking equipment allocates a unique IP address to the computing unit of the control station and of the ROV for communication and data transfer.
Referring to the Fig. 6 of the present invention, it illustrates the block diagram of the safety and distribution box in accordance with an embodiment of the present invention.

In accordance with the present invention, the high voltage DC transmission output of the safety and power distribution box enables the ROV to perform its operation to a length of 1000 metres or higher due to which the operation capability of the ROV increases. The ROV is enabled to support a long tether length due to which it may perform long tunnel inspection. The ROVis having a high thrust-to-weight ratio which enables it to perform multiple applications. The modular design of the vehicle enables it to be equipped with a wide variety of sensors and payloads for different types of applications. The ROV is capable to operate at high depths and in turbulent sea conditions. Further, the ROV has a capability to perform contact as well as non-contact Ultrasonic Testing on metal and concrete infrastructure underwater. Furthermore, the illumination system of the ROV increases its capability to conduct the underwater visual inspection in low light and in turbid water conditions.

Example 1:
The system and ROV of the present invention were tested in comparison with a conventional ROV powered by AC voltage. The tested ROV is having a power consumption of 3000 W. If the ROV was powered withan AC input of 240 VAC, 50 Hz, the AC current was found to be 14.7 A. Whereas, when a 400 voltage DC power is supplied to the ROV having a DC current of 7.5 A. The tether cable of 3C, 16 AWG having a cross section of 1.5 square millimetres (mm) was used to power the ROV. Referring to the FIG. 7 of the drawings, the graph shows the comparison of Receiving End Voltage between AC & High Voltage DC transmissions for 16 AWG Tether cable. The receiving end voltage is the voltage that reaches the ROV via. tether. It was observed that the AC transmission is capable of supporting around 150 – 200 meters of tether, beyond which the receiving end voltage falls below 180 VAC and thereafter, the power converters insideROV were failed to work efficiently at their peak specification. When ROV of the present invention was powered by the high voltage DC transmission, it was found to be capable of operating effectively and supporting 1km or higher tether length.
Advantages:
The present invention has the following technical advantages:
1. The system of the present invention is capable to perform multiple applications.
2. The present invention provides a modular and easily scalable vehicle design configuration which supports a wide variety of sensors and payloads for different types of applications.
3. The present invention provides an observation class Remotely Operated Underwater Vehicle which is small in size, light-weight, and is having a hydrodynamic design configuration due to which the ROV can survive at high depths and in turbulent sea conditions.
4. The present invention provides a Remotely Operated Underwater Vehicle having a very high thrust-to-weight ratio, making it a unique design in Observation class ROVs.

5. The present invention provides aportable system with easy deployment and retrieval of the ROV.

6. The present invention provides a Remotely Operated Underwater Vehicle capable to perform long tunnel inspection.

7. The present invention provides a Remotely Operated Underwater Vehicle having capability to perform contact as well as non-contact Ultrasonic Testing on metal and concrete infrastructure underwater.

8. The present invention provides a Remotely Operated Underwater Vehiclewhich is capable to conduct visual inspection underwater in low light and in turbid water conditions.

9. The present invention provides a ROV which can perform different underwater applications simultaneously by eliminating the need of different equipment or devices required to perform the underwater application. Thus the costs of the operations are reduced.

The foregoing description of the invention has been set merely to illustrate the invention and is not intended to be limiting. Since modifications of the disclosed embodiments incorporating the substance of the invention may occur to person skilled in the art, the invention should be construed to include everything within the scope of the disclosure.