Practical implementation of a real-time iterative learning position controller

Current control methods for chain conveyor systems in manufacturing consist almost exclusively of proportional plus integral plus differential (PID) control implemented using a programmable logic controller (PLC). A prominent feature of these conveyor systems is the simplicity of their construction, a factor that can make accurate position control difficult. To improve product throughput it is necessary to improve position accuracy. This paper describes the design and implementation of a learning controller for such a system. Experimental results are presented and compared to those obtained using a conventional PID controller.