Self-tuning control of a pH-neutralization process

A self-tuning regulator has been used in control of a pH-neutralization process. The process is difficult to control due to great variations in process sensitivity with pH and due to process nonlinearities. Experiments on a pilot plant demonstrate that a self-tuning pH-regulator including exponential forgetting and quadratic optimal control has satisfactory static and dynamic properties even though the process is nonlinear. It is also demonstrated that the self-tuning algorithm can adapt to changes in process conditions, and it may be a useful alternative to traditional PI-controllers.