Enhanced PID Controllers Design Based on Modified Smith Predictor Control for Unstable Process with Time Delay

Abstract EN

A two-degree-of-freedom control structure is proposed for a class of unstable processes with time delay based on modified Smith predictor control; the superior performance of disturbance rejection and good robust stability are gained for the system.

The set-point tracking controller is designed using the direct synthesis method; the IMC-PID controller for disturbance rejection is designed based on the internal mode control design principle.

The controller for set-point response and the controller for disturbance rejection can be adjusted and optimized independently.

Meanwhile, the two controllers are designed in the form of PID, which is convenient for engineering application.

Finally, simulation examples demonstrate the validity of the proposed control scheme.