Modeling at the machine-control level using discrete event simulation (DES)

Simulation at the machine-control level plays an important role in designing machine controls and operational specifications. Recently, there has been a considerable amount of work done in the area of manufacturing systems control. This micro-level type of modeling is as important as modeling at the plant level. The paper is an application case study of modeling at the machine control level. The objective of the paper is to address the issues of augmenting control design for automated production systems through the use of DES. The case study is an automated process of a frame turnover. In this process, an inbound conveyor transfers large frames into a turnover unit. Frames are accelerated toward the lift and rotate unit using a hydraulic slide. Frames are lifted and rolled over side to side then lowered onto an outbound pedestal conveyor. The pedestal conveyor shifts frames to the unloading station. The objectives of the case study were to visualize the turnover process and to design the sequences and timing of its operations. Based on that, it is required to verify that there is enough time for the turnover process to take place in sync with the movement of the inbound and pedestal conveyors. Finally, the machine controls are designed so that the system throughput and operational specifications are achieved.