CONTROL LAWS, TASKS AND PROCEDURES WITH ORCCAD - APPLICATION TO THE CONTROL OF AN UNDERWATER ARM

Software reliability is a major issue in the design of control archite cture for robots operating in hostile or poorly known environments. Th e ORCCAD control architecture gathers control laws in continuous time at low levels and logical aspects in discrete time at higher levels. W hile some performances can be checked using simulations, crucial prope rties such as dead-lock avoidance, safety mid liveness can be formally verified at both levels, using in particular some advantages of synch ronous programming and associated tools. In the framework of the Union project, the underlying programming style using mission composition o f the basic actions and formal verification is illustrated by the desi gn of an underwater structure inspection mission simulation using a re motely operated vehicle fitted with a manipulator. Since the physical system is not yet ready, only realistic simulation,results are provide d, but it is expected that they: will be rather easy to transfer to th e real plant.