Distributed Controller Design for Cooperative Robot Systems Based on Hierarchical Task Decomposition

Abstract

A distributed simulation and control method for humanoid robot systems based on the discrete event net models is proposed. Extended Petri nets are adopted as an effective tool to describe, design and control the cooperative behavior of robots. Based on hierarchical net decomposition, conceptual and detailed Petri net models are assigned to the upper level and the lower level controllers, respectively. For the lower level control, individual net models of robots are executed on separate local controllers. The unified net representation for the hierarchical coordination of cooperative execution control by multiple robots is proposed. Overall control software is implemented and executed on a general hierarchical and distributed control architecture corresponding to the hardware structure of robot systems. The upper level system controller and lower level local controllers are concurrently executed, communicating events information (enabled transitions) with each other, so that the cooperative robotic tasks are successfully performed.