A hierarchical approach to the collision free operation of a multi-robot workcell

The synthesis of a controller for a multirobot system is considered in this paper. An architecture based on a three layer structure which enables collision free operation of the system is described. The layers, an off-line collision free motion planner, a robust control algorithm to facilitate trajectory tracking and a real time monitor, are so arranged as to minimise the real time computational requirements of the system, thus enabling low cost implementation