Industrial Consultancy & Sponsored Research (IC&SR) , IIT Madras
Underwater Manipulator Using Variable Buoyancy Actuators
Categories for this Invention
Technology: Underwater Manipulator;
Industry: Oil & Gas, Environment Engineering;
Applications: Extraction & mining, Robotics.
Market: The global underwater Robotics market is projected to grow at a CAGR of 10.8% during 2024-2032.
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Problem Statement
- The underwater robots are being employed for various operations at higher depths, where human reach is impossible in wide applications range from search & rescue, inspection & deployment of pipes, & underwater structures, sampling of the ocean & its resources, etc. Thereby, it is required underwater remotely operated vehicles which are equipped with manipulators. Manipulators are usually serially linked rigid arms with each arm individually actuated using electric or hydraulic motors. Sealing of motors to operate at higher depths is a challenging task & the system becomes bulkier. The existing underwater vehicles, variable buoyancy system/engine is an integral part designed along with other subsystems, having other issues.
- Hence there is a need to address the issues.
Technology
- Present invention describes an underwater manipulator.
- Said manipulator comprises at least one elongated flexible structure anchored at one end & rotatable 360° about the anchor point, & having an end effector at the other end.
- The flexible structure comprising a plurality of arms connected at pin joints, each arm configured to rotate within a plane to a predetermined angle, wherein each arm comprises:
- a rigid link; and
- a variable buoyancy element forming at least a portion of the length of the arm, & the variable buoyancy element configured with flexible bellows actuated using a linear actuator assembly.
- The variable buoyancy element is configured to vary buoyancy of the arm to cause a moment that results in motion of the arm in upward or downward direction.
- Further, the manipulator is configured to place the end effector at a 3-dimensional location within a predetermined radius of the elongated flexible structure.
- The pin passive joint is configured to restrict rotation of the arm to an angle of rotation Ѳ which ranges between 0° to 90°.
- The linear actuator assembly comprises a linear actuator piston operated using hydraulic or electric means.
- Further, a method of manipulating an underwater manipulator is described.
Key Features / Value Proposition
Technical Perspective:
Standalone Unit:
- The manipulator is configured to be a standalone and anchored to a base unit on the sea or ocean floor.
- The arms of the manipulator are of varying sizes with variable buoyancy elements of capacity based on size of arm and with a biggest link placed closest to the anchor point.
Manipulator:
- The manipulator is configured to be an add-on to any autonomous underwater vehicle (AUV).
- Each arm is configured to be neutrally buoyant to reduce the load on the preceding arms.
- The moment caused due to the actuation of the variable buoyancy element is either positive or negative based on the position of the center of buoyancy (CoB) with respect to the center of gravity (CoG) along the axis of the manipulator.
- The manipulator is configured with an encoder to provide feedback including angle of orientation of each link and the depth at which the variable buoyancy element is placed.
Industrial Perspective:
- The standalone device is cost-effective & reliable.
- The efficient underwater manipulator is easily anchored to a base unit on any sea or ocean floor.
Questions about this Technology?
Contact For Licensing
sm-marketing@imail.iitm.ac.in
ipoffice2@iitm.ac.in
Research Lab
Prof. Asokan T
Department of Engineering Design
Intellectual Property
IITM IDF Ref. 1583
Patent No. 490423
PCT Application No: PCT/IN2018/050655
Technology Readiness Level
TRL- 3/4
Proof of Concept ready, tested and validated in Laboratory