The jet experience with remote handling equipment and future prospects

Abstract

The commissioning and testing of numerous pieces of equipment are now in progress at JET. Two microprocessor controlled force feedback MASCOT IV servomanipulators have shown comparable characteristics to those of the previous analogue types. Teach and repeat software permits precision welding and repetitive operations in a robotics mode. Other computer aids are planned to improve the man-machine interface: tool-weigth compensation, constraints along preferred lines or planes, automatic tracking of the TV cameras. The in-vessel transporter, provided with 5 vertical hinges, a pan-tilt-roll extension and special purpose end effectors, has been used under direct visual control to install 32 toroidal limiters and 8 radio frequency antennae. Tests of remote installation in teach and repeat were done, using the JET spare octant as a mock-up, achieving repeatability of better than 5mm. A considerable number of special remote handling tools were used inside the vessel hands-on to align, cut and weld diagnostics ports and water pipes. The cutting and welding trolleys were used hands-on, on a total of 250 m of lip joints. The ex-vessel transporter, a crane-mounted vertical telescope, 17 m high with a 10 m horizontal arm, is being manufactured. It will be equipped with manipulator and TV systems and controlled via joystick or keyboard or in teach and repeat. Image processing for collision avoidance is being studied. A low level transporter was used for turbo-pump replacement and is now being equipped with remote control. Mock-up work has started on the replacement of the Neutral Injector sources. Bench tests on flanges, heating jackets and connectors are being done to identify refinements needed. The in-vessel inspection system has been used at high temperature in vacuum.