Abstract
PID control schemes have been widely used in most of process control systems represented by chemical processes for a long time. However, it is a very important problem how to choose the optimal control parameters, i.e., PID parameters, because these parameters give a great influence on the stability and the control performance. On the other hand, self-tuning PID control has proposed for systems with unknown parameters. However, to the best of our knowledge, there is few scheme which is effective for the system with time-varying parameters.
In this paper, a new self-tuning PID control scheme is proposed, which is able to deal with such a system. The proposed scheme is derived based on the relationship between PID control and generalized minimum variance control (GMVC) laws. Furthermore, a suitable set of some user-specified parameters included in the GMVC criterion is sought by using a genetic algorithm recursively.
