PID autotuning for integrating processes with specifications on gain and phase margins

Many PID autotuning methods have been developed for open-loop stable processes, however, simple on-line identification methods which derive their transfer functions and corresponding on-line tuning rules for integrating processes are rare. In the paper, we proposed a simple on-line process identification and PID tuning method for integrating processes. With the proposed autotuning method, a loop transfer function with gain margin 3 and phase margin 60° can be obtained, which guarantee both robustness and performance. Simulation examples are given to show the better performance of the autotuning method than other methods