A Formal Approach to the Distributed Software Control for Automated Multi-Axis Manufacturing Machines

Abstract

This chapter deals with the control system design problem for automated machine systems from the viewpoint of a discrete event system approach. Behaviors of automated systems have externally the features of discrete event asynchronous, concurrent processes, which implies the necessity of distributed architecture for intelligent cooperative control. Based on the generalization of multi-axis machine activities, the detailed control functions of a machine task are hierarchically represented by an interpreted form of the Petri net. The necessary control conditions and rules to ensure that the control system is well-defined, including synchronization and conflict resolution, are provided as a conceptual model of machine task. Due to hierarchical decomposition of Petri net models, the structure of the whole control system as well as the contents of each machine task is easily understood so that the task planning, monitoring and modification of the control system can be done effectively.