Modeling and implementation of net based distributed control for industrial robotic systems

This paper presents a modeling and implementation method for complex robotic systems using multiple robots. Based on conceptual condition-event models of robotic activities, extended Petri nets are adopted as a tool for expressing independent and cooperative robotic tasks. Net models representing inter-task cooperation with synchronous interaction are implemented on hierarchical and distributed control architecture. The higher level controller executes a conceptual Petri net model representing cooperative behaviors in the system, and parallel activities of the local controllers are efficiently coordinated through the transmission of subtask commands and the reception of event status. Detailed software implementation of the inter-task cooperation in an example robotic cell, is provided.