Contributions to the control of Time-Weighted Systems

Abstract

This paper presents some contributions to a time-optimal control framework based on Time-Weighted Systems (TWS). A two-steps control synthesis method is proposed, where, first, given a TWS and a set of safety and coordination requirements, a supervisor to guarantee the former is synthesized, and, second, given a required number of productions, a supervisor that guarantees the minimum makespan (production time) is computed. We also propose a realization of a timed supervisory control map for a TWS that is robust with respect to variations on event execution times and that contains a simple control law suitable for implementation in platforms like PLCs or microcontrollers. We illustrate our approach using two Flexible Manufacturing Systems (FMS) case studies.