Abstract:

In order to control the temperature in the heat exchange system, the two degrees of freedom PID(Proportional-Integral-Derivative) control algorithm was used. The PID controller is synthesized by the Ziegler-Nichols oscillation method, and the coefficients of two degrees of freedom controller were adjusted according tothe empirical formula. A series of simulation experiments were carried out with the reference of the traditionalPID controller, including object tracking, anti-jamming, robustness testing and nominal model controlling. Thetwo degrees of freedom controller showed good performance, object tracking (better than the traditional one),and robustness. In the nominal model control simulation experiment, the system with the two degrees of freedomcontroller worked with a less rise time and a less recoil than which with the traditional controller.

Key words: the two degrees of freedom control, proportional-integral-derivative(PID) control, Ziegler-Nichols method, heat exchange control system, robustness