Abstract
Robotic manipulations in contaminated environments are often either too complex or unstructured to be performed fully autonomously for decommissioning or clean-out processes, thus; remote robotic systems, where the human operator is in the loop for direct control and making decisions, are generally employed. Bilateral teleoperation systems enabling remote manipulation of the delicate materials in hazardous conditions with high dexterity and sufficient force feedback enhance operational safety within the nuclear industry.
Typically, operators need to carry out an extensive training programme in order to safely operate such a complex robotic system in hazardous conditions, e.g., approximately 6 months for Joint European Torus (JET) tokamak maintenance which is a highly structured and well-defined process. Training the operators, however, for the challenging conditions imposed by a contaminated environment, or after a disaster (e.g., low visibility, restricted motions in the confined spaces, limited interaction force) in a time- and cost-effective manner is difficult. For training purposes, creating physical mock-ups is not always possible due to the overall uncertainty within the actual operating conditions and using the bespoke robotic systems is not always possible due to the tight maintenance and operational schedules and limitations to the number of available systems.
This paper highlights the importance of Haptic Digital Twin (HDT), a complete system with physics simulation, haptic rendering, and local haptic device(s), can prepare the operators to remotely manipulate hazardous materials more economically by simulating different tasks, robots, and their surroundings in the hazardous environment. The operational readiness level of the operator can be increased by simulating different types of representative failure scenarios (e.g., actuator or sensor malfunctions, task setbacks, etc.) and different remote manipulation tasks can be developed, verified, and validated within the virtual platform. The proposed HDT can be applied to various decommissioning processes including the post-operational clean-out process (POCO) and cleaning out the Fukushima-Daichi power plant, in particular during the fuel debris retrieval process.
