Design and application of PID controllers based on interval computing theory

This paper discusses a simple approach to design the robust controllers of PID for certain parameters of variable pitch fan control system will change at low-temperature environment. As for interval plant with variable interval parameters, a new approach is presented which is based on the Generalization of Kharitonov Theorem and a Generalization of HermiteBiehler Theorem via Interval Polynomial Stabilization Theorem and a Generalization of Hermite-Biehler Theorem. Then the parameters of robust PID controllers for interval plant can be solved through the Hurwitz stabilization of interval polynomial. Finally, some numerical examples are given to demonstrate the effectiveness of the proposed robustness of PID methods. Keywords-interval plant; Hurwitz