Adaptive control of delayed integrating systems: a PVC batch reactor

Batch processes are a real challenge for conventional proportional-integral-derivative (PID) controllers. PID tuning can be extremely difficult due to the reduced stability margins. An industrial indirect adaptive control scheme was developed and applied to more than two dozen processes with an integrating time delay characteristic. Among these a polyvinyl chloride (PVC) batch reactor was chosen to illustrate the performance of the proposed method. The scheme, which uses identification based on Laguerre functions and predictive control, allows easy automation of batch reactors. This control strategy resulted in an improved batch consistency, reduced cycle times, and increased productivity.