DESC:F O R M 2
THE PATENTS ACT, 1970
(39 of 1970)
The Patent Rule, 2003

COMPLETE SPECIFICATION
(See section 10 and rule 13)

“Multi-functional remotely operated submersible vehicle (ROV) system”
By
Planys Technologies Private Limited
An Indian company
03 - A2, 3rd Floor, IITM Incubation cell, Madras Research Park, Kanagam Road Tharamani, Chennai 600113

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 an underwater vehicle system particularly to light weight, multi-functional remotely operated submersible vehicle (ROV) system useful in working under water.
BACKGROUND OF THE INVENTION
Unmanned Underwater Vehicles (UUVs) are mobile robots which are designed to operate underwater and carry out sophisticated missions without a human occupant. Development of UUVs has enabled mankind to reach deeper realms of the oceans and access unchartered areas of water bodies round the globe, which were earlier beyond the reach of human divers. Further, these vehicles have 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), which are pre-programmed to function without any human input and remotely operated underwater vehicles (ROVs), which are controlled by a remote human pilot over an umbilical. Modern ROV systems can be categorized by size, depth capability, power consumption, and whether they are all-electric or electro-hydraulic. In general, ROVs can be grouped as follows: micro observation class, mini observation class, light work class, and heavy work class.
ROVs are deployed for a wide range of applications, which including but not limited to visual and non-destructive techniques (NDT) based inspection of immersed underwater structures, ship hull, ship propeller, rudder, ballast tank and oil tank floors. Other applications include cleaning of marine and bio-fouling growth from ship hull and underwater structures, measurement of structural thickness and cathodic protection potentials on offshore structures, determination of flooding in structural members of offshore platforms through acoustic techniques, rapid defect detection and repair of interoceanic pipelines/cable lines, bathymetric surveys using SONARs to study seabed topography, and hydrographic surveys to characterize water properties such as conductivity, temperature, pH, dissolved oxygen (DO), turbidity and oxidation-reduction potential.
An ROV is required to execute these applications at high depths and in turbulent sea conditions, including very high waves, swell and extremely strong currents. Water column depths can range up to 200 - 300 meters. Wave heights can vary up to a few meters and sea currents can be up to 4 knots. ROV has to navigate in such tough conditions to reach the target and perform inspection using the sensors and payloads.
Numerous types of ROVs are designed and developed in observation class and work class for different functionalities. The major drawbacks of these vehicles are nonexistence of single ROV system to perform multiple applications. Every vehicle in market is specifically designed to execute a particular application. Different categories of vehicles are required to execute multiple applications at the same time. Further small, light-weight ROVs cannot survive in tough sea conditions. ROVs which can survive at high depths and in tough sea conditions are extremely heavy and bulky. Other drawback includes difficulties involved in mobility, deployment and retrieval of ROV’s, and also non-modular design of ROV’s hindering addition of new sensor or payload as per the requirement. The high costs involved in providing services through existing ROVs and their maintenance is also a major concern among the existing ROVs.
Thus there is need for a ROV which aims at providing a compact solution for the shortcomings of the above mentioned systems, by providing cost-effective services in sectors of shipping, ports, dams, railway bridges, oil & gas, power plants, thermal plants and nuclear plants.
OBJECTIVE OF THE INVENTION
These objectives are provided to introduce a selection of concepts in a simplified form that are further described below in the detailed description. This objective are not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.
An important objective of the invention is to provide a light weight, multi- functional remotely operated submersible vehicle (ROV) system.
Another objective of the invention is to build a compact, modular and portable ROV which can survive in tough marine conditions at 200 meters of depth, operating in 2-4 meters of wave height and up to 1 m/s of sea currents.
Further objective of the current invention is to provide following amenities in the sectors of shipping, ports, dams, oil and gas, power plants, thermal plants and nuclear plants:
• Visual and non-destructive techniques (NDT) based inspection of immersed underwater structures.
• Ship hull, ship propeller, rudder and ballast tank inspection.
• Cleaning of marine and bio-fouling growth from ship hull and underwater structures.
• Measurement of structural thickness and cathodic protection potentials on offshore structures.
• Determination of flooding in structural members of offshore platforms through acoustic techniques.
• Bathymetric surveys using SONARs to study seabed topography.
• Hydrographic surveys to characterize water properties such as conductivity, temperature, pH, dissolved oxygen (DO), turbidity and oxidation-reduction potential.
• 3D imaging and profiling of immersed objects and structures.
Objective of the present invention is not limited to the above mentioned problem. Other technical problems that are not mentioned will become apparent to those skilled in the art from the following description.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will now be described in greater detail with reference to an embodiment which is illustrated in the drawing figures:
Figure 1 shows power and communication architecture of the ROV system, according to an embodiment of the present invention;
Figure 2 - 3 shows isometric view of ROV showing various parts, according to an embodiment of the present invention;
Figure 4 shows power architecture of a ROV, according to an embodiment of the present invention;
Figure 5 shows thruster configuration in a ROV, according to an embodiment of the present invention;
Figure 6 is an image showing ROV GUI, according to an embodiment of the present invention; and
Figure 7 is an image showing pilot cockpit, according to an embodiment of the present invention.
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.
In the claims, all transitional phrases such as "comprising," "including," "carrying," "having," "containing," "involving," and the like are to be understood to be open-ended, i.e., to mean including but not limited to. Only the transitional phrases "consisting of and "consisting essentially of," respectively, shall be closed or semi-closed transitional phrases.
To facilitate the understanding of this invention, a number of terms may be defined below. Terms defined herein have meanings as commonly understood by a person of ordinary skill in the areas relevant to the present invention. Terms such as "a", "an", and "the" are not intended to refer to only a singular entity, but include the general class of which a specific example may be used for illustration. The terminology herein is used to describe specific embodiments of the invention, but their usage does not delimit the disclosed system or method, except as may be outlined in the claims.
This invention relates to underwater vehicle system 100 useful in working under water such as for the purpose of making visual surveys, making scientific or engineering inspections, searching for wrecks or salvage, seeking lost articles and for collecting data in relation to pressure, currents, saline content, radio-activity, temperature and for the ascertainment of underwater conditions.
Figure 1 shows power and communication architecture of the ROV system 100, according to an embodiment of the present invention. The multi-functional remotely operated submersible vehicle (ROV) system 100 according to the invention, comprising of a distribution box 102 connected to a power source 104 for transferring power and communication. A tether management system 100 and a command module 106 are connected to said distribution box 102 through a cable configured for transferring said at least one of power and data with said distribution box 102, and a remotely operated vehicle (ROV) 100 for performing multiple underwater operations connected to said tether management system 100 through a tether, said tether being configured for transferring at least one of power and data with said ROV 110.
The distribution box 102 distributes power from power source 104 to ROV 110, command module 106 and any other auxiliary device. It has short circuit, over-current and earth leakage protections through safety fuse, MCB and RCCB. It also consists of a powerline communication adapter which gets paired with other adapter inside ROV 110 upon power. This adapter is connected to Wi-Fi router through an ethernet cable and allocates a unique IP address to the ROV 110 for data transfer.
The tether management system (TMS) 108 efficiently manages the long 200 meters, neutrally buoyant umbilical cable or tether. It consists of a slip ring of adequate power rating for easing winding and un-winding of the cable.
Powerline communication protocol is being used to communicate with the ROV 110 remotely over umbilical cable. This method uses Gigabit adapters, which embed the data over power line, and support a downlink and uplink bandwidth of nearly 100 Mbps across 200 meters long cable. This facilitates 2-way transmission of videos, sensory data and joystick commands between ROV 110 and command module 106.
ROV pilot uses command module 106 for controlling the remotely operated vehicle 110. It is equipped with sunlight readable display screen with graphical user interface (GUI) and cockpit for assisting the pilot in manoeuvring the ROV 110 from the control station.
Further the launching and retrieval system (LARS) is designed for easy and safe launching and retrieval of the ROV 110 to and from the water using a garage from a maximum height of 30 meters.
Figure 2 - 3 shows isometric view of ROV 110 showing various parts, according to an embodiment of the present invention. Accordingly, the ROV 110 is characterised by a structural frame 112 adapted to support state of the art dual hull viz. a power hull 114 and an electronics hull 116. The power hull 114 configured to enclose a power transmission configuration, comprising of a AC/DC converter 114b converting input AC voltage to output DC voltage, a DC/DC converter 114c connecting in series to AC/DC converter 114b converting DC voltage from one level to another, wherein the DC/DC converter 114c connected to an electronic speed controller (ESC) 114e through a DC bus bar 114d drives plurality of modules mounted on said structural frame 112, and said electronics hull 116 having a processor coupled to receive and transfer data from and to the plurality of modules.
Structural frame 112 provides structural integrity to the ROV 110. ROV 110 consists of a plastic frame 112 in hydrodynamic shape. In a particular embodiment plastic frame 112 is made of Polypropylene material. The hulls are mounted on the frame 112 in an arrangement which provides equal thrust to drag ratio in surge and sway directions. In a preferred embodiment said arrangement can be in perpendicular. Further apt distance is retained between the power hull 114 and the electronics hull 116 to achieve requisite parting between center of buoyancy and center of gravity. Other enclosures and payloads are mounted on structural frame 112 in a compact fashion.
The hulls are watertight, cylindrical shaped, aluminium hulls which house power and electronic circuits. The hulls are made waterproof using O-ring face seal mechanism. O-ring gets sandwiched between the hull and its end-plate, providing water-tightness up to 200 meters of depth. The end plates consist of watertight connectors to facilitate waterproof connections of sensors and payloads with the circuits inside the hull. The heavy bottom hydrodynamic design provides ROV 110 static and dynamic stability in harsh underwater environment. And also the heavy bottom feature of the vehicle inhibits roll motion.
The plurality of modules are the various kinds of payloads carried by the ROV 110 which can be a thruster module 118 and/or lighting module 120 having high intensity lights and/or an imaging module 122 including high-definition cameras, 2D & 3D imaging/scanning SONARs, side scan SONAR and/or a cleaning module 124 like bio-fouling cleaning equipment and/or a measurement module 126 such as LASERs as crack measurement unit, ultrasonic thickness measurement unit, cathodic potential measurement unit. ROV 110 also consists of an altimeter 128, an emergency pinger 130, an IMU for orientation feedback, pressure sensor 132 for depth feedback, a GPS for position feedback on water surface and buoyancy foams 134 at the top.
Further, ROV 110 comprises watertight metal and/or plastic enclosures to house cameras, high intensity lights and pressure sensor. Cameras and lights enclosures consist of a transparent acrylic screen. These are made waterproof using O-ring face seal and bore seal mechanisms.
Figure 4 shows power architecture of a ROV 110, according to an embodiment of the present invention. In a preferred embodiment, the power transmission configuration of the ROV 110 supplies AC/DC power from a universal grid supply 104 of 90-274VAC, 50/60 Hz. The power is transferred from the source (generator) to the ROV 110 over a long neutrally buoyant umbilical cable. AC/DC power is then converted to intermediate bus voltage 114b. The DC/DC converter 114c connected to an electronic speed controller (ESC) 114e through a DC bus bar 114d drives plurality of modules mounted on said structural frame 112.
The power transmission configuration of the ROV 110 further consists of a thermal architecture having plurality of cooling means 114f dissipating heat from pressure hull to surrounding. The cooling means 114f can be a heat sink or a cooling fan sited inside the power hull 114. Cooling fans transfer the heat to Aluminium hull via convection, which in turn gets cooled down by surrounding water through principles of conduction. The thermal architecture comprises multiple fans in different directions. In an embodiment, thermal architecture includes six fans in longitudinal direction along the power hull 114, and four fans in transverse direction across the power hull 114, creating turbulent air flow inside the power hull 114 ensuing higher heat transfer coefficient.
Figure 5 shows thruster configuration in a ROV 110, according to an embodiment of the present invention. The thrusters 118 are vector configured to propel ROV 110, wherein six thrusters are positioned in horizontal plane and two in vertical plane enabling five degrees of freedom with an operating speed of 3-4 knots to operate ROV 110 under stable condition. In a preferred embodiment, the ROV 110 uses eight brushless thrusters 118 to control five degrees of freedom, wherein four thrusters 118a in vectored configuration, mounted symmetric to the longitudinal axis, provides independent control for surge, sway and yaw motions. Two vertical thrusters 118b placed symmetric to the lateral axis provide heave and pitch control in diving plane. Two additional horizontal thrusters 118c, mounted symmetric to the longitudinal axis, provide added thrust in surge direction. Pulse-width-modulator (PWM) of each thruster is controlled through a custom designed Electronic Speed Controller (ESC), which provides feedback on temperature and RPM parameters. Every ESC communicates with System Monitoring and Control Unit (SMCU).
Electronics hull 116 in the ROV 110 comprise of a processor or a computing unit, micro-controller, communication unit, various sensors and payloads. Micro-controller mainly controls PWM of each thruster via SMCU, power and communication with sensors and payloads, intensity of all lights in illumination system, and toggling of LASERs.
Figure 6 is an image showing ROV GUI, according to an embodiment of the present invention. The graphical user interface (GUI) for piloting ROV 110 allows effective operation and control of the ROV 110 by the pilot, whilst the ROV 110 simultaneously feeds back information that aids the operators' decision-making process. The proposed GUI produce a user interface which makes it easy (self-explanatory), efficient, and enjoyable (user-friendly) to operate a ROV 110 in the way which produces the desired result. The other components include, device manager which communicates with all the devices attached in the ROV 110, mission controller communicate with the micro controllers of ROV 110. Further, remote controller is a component that fetches data from joystick device and sends to server in the ROV 110. Post-processing components takes the input from final output of system and creates a client deliverable content. Cockpit is pilot mode user interface with minimal data used while piloting along with the video feed. The corresponding figure 7 is an image showing pilot cockpit, according to an embodiment of the present invention.
All the components mentioned above are interrelated and their data is shared using Inter Process communication (IPC) methods. The development of these components follows modular architecture. These components are dependent on hardware devices, sensors, payloads and any additional features from the ROV specifications list.
In addition, the architecture supports multiple communication modes viz. RS232, RS485 and USB communication modes, enabling easy interface for a large variety of payloads such as altimeter, side scan SONAR, imaging SONARs, ultrasonic thickness measurement unit, cathodic potential measurement unit, cleaning unit, GPS, etc.
The ROV system 100 of the present invention provides highly modular vehicle design supporting a wide variety of sensors and payloads for different kind of applications. The light-weight multi-functional ROV system 100 can survive at high depths and in moderately tough sea conditions. And also said ROV system 100 is highly portable with easy deployment and retrieval providing cost-effective services.
Although but one preferred embodiment of the invention has been illustrated, it will be obvious to those skilled in this art that other embodiments may be readily designed within the scope and teachings thereof.
Having thus described an embodiment of the invention, it is obvious that the same is not to be restricted thereto, but is broad enough to cover all structures coming within the scope of the annexed claims.
,CLAIMS:I/we claim,
1. A multi-functional remotely operated submersible vehicle (ROV) system, comprising:
a distribution box connecting to a power source for transferring power;
a tether management system and a command module attached to said distribution box through a cable configured for transferring said at least one of power and data with said distribution box; and
a remotely operated vehicle (ROV) for performing multiple underwater operations connected to said tether management system through a tether, said tether being configured for transferring at least one of power and data with said ROV, such that ROV is characterised by a structural frame adapted to support a power hull and an electronics hull, the power hull configured to enclose a power transmission configuration, consisting of a AC/DC converter converting input AC voltage to output DC voltage; a DC/DC converter connecting in series to AC/DC converter converting DC voltage from one level to another, wherein the DC/DC converter connected to an electronic speed controller (ESC) through a DC bus bar drives plurality of modules mounted on said structural frame, and said electronics hull having a processor coupled to receive and transfer data from and to the plurality of modules.
2. The multi-functional ROV system according to claim 1, further comprises of a launching and retrieval system (LARS) for launching and retrieval of ROV to and from the water.
3. The multi-functional ROV system according to claim 1, wherein said power hull and said electronics hull are mounted on said structural frame in an arrangement which provides equal thrust to drag ratio in surge and sway directions.
4. The multi-functional ROV system according to claim 2, wherein said arrangement is perpendicular.
5. The multi-functional ROV system according to claim 1, wherein the plurality of modules is a thruster module and/or lighting module and/or an imaging module and/or a cleaning module and/or a measurement module.
6. The multi-functional ROV system according to claim 1, wherein said power transmission configuration of the ROV further consists of a thermal architecture having plurality of cooling means dissipating heat from pressure hull to surrounding.
7. The multi-functional ROV system according to claim 6, wherein said cooling means is a fan and the thermal architecture comprises plurality of fans in longitudinal direction along the power hull, and in transverse direction across the power hull, creating turbulent air flow inside the power hull ensuing higher heat transfer coefficient.
8. The multi-functional ROV system according to claim 1, wherein the thrusters are vector configured to propel ROV, wherein six thrusters are positioned in horizontal plane and two in vertical plane enabling five degree’s freedom to make ROV stable.
9. The multi-functional ROV system according to claim 1, wherein said structural frame is made of plastic material which is formed to hydrodynamic shape for providing structural integrity to the ROV.
10. The multi-functional ROV system according to claim 1, wherein apt distance is retained between the power hull and the electronics hull to achieve requisite parting between center of buoyancy and center of gravity.