The Joint European Torus (JET) is the world’s largest and most powerful fusion research device. The JET design includes a bespoke system for remote maintenance. Its 12m long snake-like booms reach into the vacuum vessel, delivering cameras and tools that enable operators to work remotely. The primary tool is MASCOT, a local-remote manipulator with haptic feedback, that allows the operator to feel every action from carrying a new component to tightening a bolt.
In order to update the booms and MASCOT, a suite of bespoke test platforms have been created as part of the Remote Handling System Maintenance and Enhancements (RHSME) programme. Included within this are:
Boom Simulator
The Boom Simulator is a self-contained, miniature scale, simulated boom joint that is representative of those in the JET remote handling system. It comprises servomotors and a gearbox, tachometers, resolver and potentiometer feedback devices, a brake and limit switches.
The Boom Simulator supports connections to the control drive hardware, enabling end-to-end testing and evaluation of the new boom control system. The Boom Simulator hardware has now been commissioned, allowing the RHSME Programme to progress with key integration activities, including initial evaluation of the plant new control drive system.
MASCOT Local Unit Mounting Stand
RACE’s Mascot 6 Team has completed the validation of the new Local Unit Mounting Stand. This confirmation means that it fulfils the safety criteria and adequate structural capacity to allow the installation of the new Mascot 6 Local Manipulator.
The load test involved a photogrammetry survey, which was performed whilst incrementally increasing weight was added to the attached lifting adaptor. This simulated the forces exerted by the Local Manipulator under safe conditions. Analysis confirmed that the column was within the predicted values and conformed to the safety standards required for an end user to be positioned underneath the stand during operations.
This success marks a significant achievement in the progression of the Mascot 6 Project, as the Local Unit is now located in the RACE Control Room and assembled ahead of the system integration testing.
MASCOT Remote Manipulator Cubicle
The Mascot 6 Team has successfully carried out the functional commissioning of the proof-of-principle Remote Manipulator Control Cubicle.
This enables the RHSME Programme to progress with the final stages of commissioning activities for the Mascot 6 system – a test platform for proving the performance of key technologies used before the system is manufactured and deployed at JET. The Remote Manipulator Cubicle is one of the many subsystems of the Mascot 6 system. It is responsible for the control of the seven degrees of freedom, two-armed remote manipulator device that enters the JET vessel.
The cubicle is designed with a high degree of modularity, allowing fault diagnostics or commissioning of key subsystems to be performed off-line and then swapped into the live system, reducing the amount of down time.
