Manufacturing-Oriented Discrete Process Modeling Approach Using the Predicate Logic

Part machining is a discrete manufacturing process. In order to evaluate the manufacturing process, an intelligent modeling method based on the first-order predicate logic is proposed. First, the basic predicate formula is defined according to the machining method, and the predicate and variables are illustrated in detail. Thus, the process representation is completed. Second, to construct the process model, the modeling element is put forward, which includes three nodes. Components of modeling element are, respectively, discussed, as well as the mapping relationship between modeling element and predicate. After the definition of modeling predicate formula, five basic inference rules are established. Consequently, the manufacturing process model is constructed. Third, on the basis of the process model, the process simulation is carried out to evaluate the manufacturing performances, such as the production efficiency, the utilization rate of machining equipment, the production bottleneck, etc. Finally, a case study is conducted to explain this modeling method.