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Contenu archivé le 2022-12-27

UNDERWATER ELECTRICAL TELEMANIPULATION SYSTEM WITH FORCE REFLECTION

Objectif

To bring to operational level an existing telemanipulation system laboratory prototype, including a master arm, an electrically actuated underwater manipulator and a control system.
To optimise the manipulator design to minimise weight vs. lifting capability and maximise dexterity and accuracy. To split the control system into a surface controller and a subsea controller, communicating via a digital link.
To improve the system operability by implementing force reflection control, which makes the operator sense, through the master arm, the force exerted by the remote manipulator. To provide the control system with robotic functions, as well. To finalise the underwater telemanipulation system for installation onboard ROVs, for the execution of complex inspection, installation, maintenance tasks of offshore installations and underwater systems.
To demonstrate the performances of this system through extensive tests.
The project has successfully brought to operational level an existing demonstrator, developed by Tecnomare - Ansaldo within a previous R&D project. The resulting telemanipulation system includes an underwater electrical arm and a small scale replica master arm providing master/slave teleoperation with force reflection. The achieved manipulator arm performances are: total length of about 2 meters, weight in air of about 145 kg, lifting capability at full reach of about 30 kg in air and 40 kg in water. It is expected that the new technology (accurate underwater telemanipulation, with force reflection and controllable also in telerobotic mode) will improve and simplify the current inspection, installation and maintenance operations at sea. In the medium term, this technology can bring to a simplification of new marine systems and maintenance systems, designed to be serviced by such manipulation systems that would flexibly substitute the current dedicated, purpose built equipment.
This system has four physical components: the master arm, operated by a human operator; the remote slave arm (the telemanipulator) which "copies" the movement of the master arm for the performance of the remote task (master-slave control); the surface controller, which controls the master arm and transmits commands to the telemanipulator via a digital telemetry link; the underwater controller, to be enclosed in a pressure resistant canister to allow underwater operations, which controls the telemanipulator. The telemanipulator is anthropomorphic and features 2 electromechanical rotary actuators at the shoulder, one at the elbow and three at the wrist, plus a parallel jaw type gripper. The arm kinematic design maximises dexterity (i.e. capability to change orientation of the end effector around reached points). The actuators are cylindrical and house a high speed DC brushless motor, a reducer and the position and torque sensors. The structural material is aluminium alloy. The actuators and wiring are pressure compensated and oil filled. The master arm is in scaled kinematic correspondence with the remote arm. The master arm joints are not only instrumented to give position setpoints for the remote arm but also motorised to give the operator the feeling of the force exerted by the remote arm. The slave arm has been redesigned to streamline the previous prototype: weight is reduced by about 20 kg and length by 110 mm. A force/torque sensor has been introduced at the wrist to measure the interaction at the end effector tool with the environment. A new type of torque sensors, based on strain-gauges, has been implemented at the arm joints. A sophisticated control system has been implemented, to provide millimetric positioning accuracy of the telemanipulator, as well as accurate reflection at the master arm of the forces exchanged by the remote arm. To reach this goal, both control units have been provided with fast processing capabilities and innovative controlloops have been implemented at the arm joints. The control system has also been provided with built-in robotic functions and has been designed to allow for future interfacing to an external computer, acting as host, providing more sophisticated telerobotic functions.

Appel à propositions

Data not available

Régime de financement

DEM - Demonstration contracts

Coordinateur

TECNOMARE SPA - SOCIETA PER LO SVILUPPO DELLE TECNOLOGIE MARINE
Contribution de l’UE
Aucune donnée
Adresse
SAN MARCO 3584
30124 VENEZIA
Italie

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Coût total
Aucune donnée