Object-oriented design and simulation of automated manufacturing system

As the level of factory automation increases, proper design and verification of control logic is an imperative task for the successful operation of an automated manufacturing system. Proposed in this paper is a design and verification method of PLC control logic using object-oriented methods for improving the limitations of current PLC logic design practices. An object-oriented design model for PLC control logic consists of three submodels: a functional model; a structure model; and an interaction model. Using the results of the object-oriented design model, the O-O discrete event simulation model is constructed by hierarchical decomposition of an automated manufacturing system and reuse of existing resource classes, and is executed for the verification of detail PLC control logic in parallel with the overall performance evaluation. Generated simulation model can be also used as a communication tool among factory automation engineers who have different experiences and disciplines.