Innovations in dismantling robotics
Introduction
In the field of using robots in hostile environments, the 1970s were essentially dedicated to exploratory development work. The 1990s have seen the arrival at operational demonstration models, thanks in particular to progress made in computerised instrumentation and control. In view of the current state of technological progress, the first industrial applications of remote operation and nuclear robotics can now be envisaged. This presentation describes the innovations that the CEA has made in the field of remote operation and robotics for dismantling.
Nuclear robotics began with the development of specialised machines essentially intended for repetitive, programmed reactor maintenance operations. Systems were developed for specific tasks, in order to have robots able to work under accident conditions and for exceptional maintenance work. The current needs mainly relate to installation maintenance (power stations, reprocessing plants), general work and dismantling, for which the robots must be reliable, easy to install and use, and able to rapidly respond to a set of missions.
For the dismantling tasks, developments include powerful handling devices and their carriers, as well as effective and safe resources making it possible to work in unstructured and/or unfamiliar and changing environments. Development work has also been carried out on the tools for preparing the tasks and then carrying them out.
The needs of the CEA, which has a major programme for dismantling its installations, are considerable. The current demand comes from the Nuclear Installations Dismantling Unit (UDIN) and the UP1 operating organisation.
Section snippets
Implementation of processes using the RD500 remote-controlled manipulator
In the 1980s, the RD 500 remote-controlled manipulator device was developed by the CEA in collaboration with Cybernetix, for dismantling nuclear installations. It is a powerful robot (500 Newtons) which performs a whole range of tasks requiring strength and dexterity (cutting, packaging, decontamination, etc.) (Fig. 1).
Its main characteristics are a total weight of 330 kg, active load balancing, a maximum travel speed of 0.5 m s−1, accuracy in repetitive tasks better than 1 mm.
In the context of
TAO 2000 computer-aided remote operation
The objective of a computer-aided teleoperation control system is to help the operator to carry out complex remote tasks. These tasks vary greatly in nature, they may require great dexterity, or be repetitive or even require considerable accuracy, in particular for implementing a process.
The TAO 2000 system, developed by the CEA, meets these requirements. It enables the slave manipulator to be controlled according to master-slave mode, semi-automatic mode (man and machine share control) and
Simulation tools
Being able to simulate dismantling sites is an important advantage for industrial operators both as a decision making aid, and a supervision aid. Indeed, simulation makes it possible to test various dismantling scenarios, thus helping to choose the most suitable, depending on various technical, economic, dose-related or other criteria.
Simulation can be used to check whether a robot is suited to the tasks required, to validate the operations which will be able to be carried out with the robot,
Conclusion
It can be noted that robotics is now a mature and reliable technology (both mechanically and as concerns control) and that the developments achieved, (in particular as regards computer algorithms) make it possible to envisage industrial applications in the short term. The robots will therefore be ready to quickly adapt to the very varied dismantling tasks. The mixing of automatic modes and safety and enhanced traceability of operations is possible thanks to permanent operator supervision.