Application of the encapsulated actuator model to the sequential control of machines

This paper proposes a new software design methodology for programmable controllers, using sequential function chart (SFC) and encapsulated actuator model of mechanical actuators. Based on the hybrid programming with SFC and ladder logic diagram (LLD), the part of the LLD is standardized and encapsulated for a description of each actuator's interlocks. To meet the demands of frequent improvement and modification in control programs for mechanical actuators, the concept of encapsulated actuator model realizes flexibility in design, testing, and maintenance. This concept is expected to be extensively applied to machine control in the large-scale factory automation system of manufacturing industries.