Automatic re-tuning of PI controllers in oscillating control loops

Abstract

A new method for online process identification and PI controller tuning is proposed. In the method presented, a standard PI control loop is tuned so as to become unstable through aggressive controller settings, and the oscillations obtained are used for process identification and subsequent controller tuning. The proposed method manages to handle load disturbances during identification and the controller is tuned with amplitude-and-phase-margin specifications.