Claims:We Claim:

1. A control communication system for use in subsea, the system comprising:
a remotely controlled underwater submersible device (RCUSD) having a plurality of modules including a first Power Line Communication Unit (PLCU); and
a control station unit comprising of a second Power Line Communication Unit (PLCU), a computer, a control joystick, necessary networking hardware and a tether management system (TMS) connecting the control station and the RCUSD, and
a remote human operator (RCUSD Pilot) situated at the control station or at any other place connected to the control station over internet or a local network,
the first and the second PLC Unit are operatively coupled (paired) using pre-defined set of communication protocol(s) by transmitting data over cable carrying Alternating Current (AC) or Direct Current (DC) power supply to the RCUSD from the control station.

2. The system of claim 1, wherein the tether is mounted on a tether management system which contains a slip-ring that allows the transmission of power and electrical signals from a stationary to a rotating structure.

3. The system of claim 1, wherein the PLC takes in data in the form of Ethernet connection.

4. The system of claim 1, wherein the plurality of modules on the remotely controlled underwater submersible device communicate with the remotely operated underwater vehicle processor and then the data is transmitted over the first PLCU of the RCUSD to the second PLCU of the remote control station and vice-versa.

5. The system of claim 4, wherein the data received at the second PLCU of the remote control station is transferred to the remote control station processor via router, wherein the router is used to have a common network established for the two processors.

6. The system of claim 1, wherein the PLCU defines both data and power pathway between the remotely operated underwater vehicle and the remote control station via communication interfaces, thereby minimizing the number of cables required to control the RCUSD and to provide a reliable communication between the RCUSD and the remote control station.
, Description:FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
(See section 10, rule 13)

“A system for communication with a remotely controlled underwater submersible device using a tether”
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 invention relates to remotely operated underwater vehicles, systems or devices, and more particularly relates to a system of communication between electric powered underwater submersible device and a remotely situated control station using a tether and tether management system.

Background of the Invention

Remotely operated underwater vehicles (ROV) are remotely controlled via a tethered connection cable, usually by a human operator who commands control inputs to the underwater vehicle, for example from a control station of the operation platform, such as a surface ship, boat or an offshore platform. Remotely operated vehicles are typically deployed subsea when and as needed but are often linked to a deploying ship by a tether management system, an assembly used to help deploy and manage the ROV from the surface to the working depth. An ROV also typically requires an umbilical cable, usually an armored cable, which contains a group of electrical conductors and fiber optics to carry electrical power, video, and data signals between Remote control station and the ROV. In the current art, a tether management system may be used in conjunction with an ROV for various purposes. Typically, a tether management system is a garage-like device or cage which contains the ROV and its tether spool, used when the ROV is being lowered into the water or it resembles a separate top-hat like assembly which sits on top of the ROV while the ROV is being lowered into the water. The tether management system is used to relay the signals and power for the ROV down the tether cable. Once at the ROV, the electrical power is distributed between the components of the ROV. A current art tether management system may comprise the ability to affect multiple functions such as lighting, an electronic control system, cameras, and an electro-hydraulic system to power various components during ROV deployment.
The ROV system consists of various modules such as video cameras, lights, electronics, pressure vessels, various sensors, and its support systems such as control station, tether management system and launch and recovery system (LARS). AC or DC power is used to power the ROV over tether for power and further used as a carrier for communication. The ROV consists of electrical thrusters for the motion of ROV underwater. A method of communicating with the ROV (underwater vehicle) comprising a propulsion system for propelling the vehicle through the water. Communication can be performed over a wired or wireless media. High frequency or high bandwidth underwater communication is not feasible through a wireless media due to the physical limitation of the carrier signals, which attenuate rapidly over short-distances underwater. Wired connections can be divided further; methods which require dedicated communication lines and methods which can be overlayed or carried over existing data/power lines. Having dedicated lines require additional cost, equipment and adds to the cable construction which plays a significant role in the control aspects of ROV
Further, another method utilizes batteries as a direct DC power source for the ROV and uses only and dedicated communication lines over the tether. While, using batteries eliminates the requirement to run power to the ROV over tether, it limits the endurance of operation as only a finite amount of battery power can be carried by the ROV. Further, the weight of the battery system increases additional complexities and costs.
The present invention addresses these and other limitations associated with conventional inspection vehicles and inspection protocols.
Summary of the Invention
An aspect of the present invention is to address at least the above-mentioned problems and/or disadvantages and to provide at least the advantages described below.
Accordingly, in one aspect of the present invention relates to a control communication system for use in subsea. The system includes a remotely controlled underwater submersible device (RCUSD) having a plurality of modules including a first Power Line Communication Unit (PLCU); and a control station unit includes of a second Power Line Communication Unit (PLCU), a computer, a control joystick, necessary networking hardware and a tether management system (TMS) connecting the control station and the RCUSD, and a remote human operator (RCUSD Pilot) situated at the control station or at any other place connected to the control station over internet or a local network. The first and the second PLC Unit are operatively coupled (paired) using pre-defined set of communication protocol(s) by transmitting data over cable carrying Alternating Current (AC) or Direct Current (DC) power supply to the RCUSD from the control station.
Other aspects, advantages, and salient features of the invention will become apparent to those skilled in the art from the following detailed description, which, taken in conjunction with the annexed drawings, discloses exemplary embodiments of the invention.

Brief Description of the Drawings
Figure 1 illustrates a remotely controlled underwater submersible device (RCUSD) and a control station in operational relation to each other, according to one embodiment of the present invention.

Detail 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.
The invention relates to a remotely controlled underwater submersible device (RCUSD), and relates to a system of communication between an RCUSD and a remote control station using a tether and tether management system.The objective of the invention is to minimize the number of cables required to control the RCUSD and to provide a reliable communication between the RCUSD and the control station.
RCUSDs perform various maintenance and inspection procedures on underwater infrastructure. In an example embodiment, the RCUSD is a Remotely Operated Underwater Vehicles (ROV). In order to maintain the relative positioning of the RCUSD and the control station, the control station can track the relative position of the RCUSD. The control station is further capable of detecting the position of the RCUSD and automatically adjusting the position of the RCUSD in order to maintain the alignment between the control station and the RCUSD.
The control station can include a tracking module that includes various sensors that can be used to determine the position of the RCUSD. For example, the tracking module can include an acoustic localization system to track and determine the position of the underwater robot. The RCUSD can use a set of sensors that include but not limited to, cameras, imaging sonars, altimeters, pressure and depth sensors, and temperature sensors that provide information about the surrounding environment and its physical properties.The cameras may be monochrome or color, standard definition, enhanced definition, high definition, or low light and may be fixed or have panning and tilting capability. The communication of the above modules maneuvering of control station with the control station plays a key role in control and maneuverability of the RCUSD by a human operator working on the control station.
As illustrated in figure 1, in an embodiment, the present invention relates to a control & communication system for use in subsea. The system for communication between a remotely controlled underwater submersible device (RCUSD) and a control station includes a RCUSD, different modules, a tether mounted on a tether management system, two PLC (Power Line Communication) units, two CPU (Central Processing Unit), a router, and a Control station. The remote human pilot is situated at the control station to perform RCUSD control and navigation, by using control inputs being sent over the communication interface established between the control station and RCUSD. Both the PLC units use a pre-defined protocol for pairing-up and communicating between themselves while being connected on the same power line. The present invention uses AC power being supplied over the umbilical or tether, however the same can be extended to DC supply.
The tether management system may contain a slightly positively or negatively buoyant tether winched onto a submersed drum or onto a surface drum (non-submersed). The tether management system (TMS) allows RCUSD operation without requiring the support vessel to move around and also eliminates the need to shift the position of the control station.
The two PLC units are placed, one near to the control station and other is situated inside the RCUSD.The control station and the RCUSD are configured to electrically couple to provide electrical power from the control station to the RCUSD. Further, the control station is configured to control operation of the RCUSD using control signals that are communicated between the control station and the RCUSD via communication modules. The RCUSD is configured to transmit data collected by RCUSD using data signals to the control unit via communication modules. The RCUSD includes underwater motion module (propulsion system) and may also contain an underwater crawling module. The RCUSD propulsion system includes at least one of a vertical thruster, a horizontal thruster, or a buoyancy control device and various combinations thereof. The underwater crawling module includes at least one of a crawling skid, a track, a wheel, an actuated leg and various combinations thereof. The RCUSD can communicate using signals e.g., by light/led, laser, acoustic or via an umbilical) with the control station via communication modules located on the RCUSD and control station.
The PLC (Power Line Communication) unit uses a protocol through electrical wiring to simultaneously carry data over Alternating Current (AC). All the modules onboard the RCUSD, communicate with the RCUSD CPU, and then the data is transmitted over the RCUSD PLC housed inside the RCUSD to the control station PLC. Further data is transferred from control station PLC to router and from router to control station CPU. The RCUSD PLC also receives data from the control station PLC for maneuvering. The connection between the two PLC is an AC or DC tether which is mounted on tether management system.The tether conveys control signals to the RCUSD, relayed via the umbilical and the tether management system. Further, the tether returns data and images back to the control station.Since the PLC takes in data in the form of Ethernet connection, a router is used to have a common network established for the two CPUs. Software changes/updates to the controller program and updating the I/O configuration can be done remotely using the Ethernet connection; i.e. any file can be copied, deleted or erased. Another benefit of an Ethernet based communication link is that a secure, high speed internet connection can be used which would allow for remote control from anywhere in the world.The tether management system contains a slip-ring that allows the transmission of power and electrical signals from a stationary to a rotating structure.