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 architecture for robots operating in hostile or poorly known environments. The Orccad control architecture gathers control laws in continuous time at the low levels and discrete time logical aspects at higher levels. While some performances can be checked using simulations, crucial properties such as deadlock avoidance, safety and liveliness can be formally veriied at both levels, using in particular some advantages of synchronous programming and associated tools. In the framework of the Union project, the underlying programming style using mission composition from basic actions and formal veriication is illustrated by the design of an underwater structure inspection mission simulation using an ROV tted with a manipulator. Since the physical system is not yet ready only realistic simulation results are provided, but it is expected that they will be rather easy to transfer on the real plant.