Detection of defective carrier trolleys utilizing a PLC realizing a sequential finite state machine for pattern recognition

Today in major U.S. automotive manufacturing facilities, conveyors are the primary means by which material is transported throughout the manufacturing facility. In the final automobile assembly facilities of major U.S. automotive companies, extensive use of a conveyor system is the primary means by which heavy components such as chassis, engines and automobile bodies are moved throughout the facility. Any downtime associated with these systems can result in a severe financial impact on the manufacturing operation. The critical component that has lead to many hours of downtime has been the carrier trolley wheels. A considerable amount of expense and effort can go into repairing the carrier while in the processing system. This paper explains efforts to design a system that will detect defective trolley wheels operating in the conveyor system. The article presents a practical application of applying advanced software development techniques to the generation of a Programmable Logic Controller (PLC) program utilizing ladder logic software