ABSTRACT
Industry is moving toward open-architecture control systems for manufacturing automation. There are two distinct types of control systems in a typical automated manufacturing system: continuous control and discrete event control. This chapter discusses the problem of discrete event control related to manufacturing systems, how industry solves these control problems, current trends in the area, and formal methods that can be used to design and analyze the discrete event control systems used in manufacturing. It focuses on the discrete event control and neglect the interactions between discrete event controllers and the continuous controllers. Discrete event control problems encountered in manufacturing systems consist of the logic and sequence coordination, error recovery, and manual control. The logic controller governs the sequence of the manufacturing process. The sequencing behavior of a manufacturing system can be specified in many different ways. A major task in the design of manufacturing systems is the design and programming of the logic controllers.
