Design and Stability Analysis of Fuzzy Switching PID Controller

Fuzzy switching PID (FS-PID) controller proposed in this paper consists of a TS-PID controller and a conventional PID controller which switching according to the premise variable in operating regime rules. This technique integrates the advantages of both the fuzzy controller and PID controller but eliminates their disadvantages. FS-PID controller provides good performance during the transient phase and alleviates oscillatory when system approaching equilibrium point. The switching between two controllers is governed through fuzzy rules. It results in smooth switching between two operating regimes. The stability condition of closed-loop systems is derived through passivity theorem. The application to the third-order linear system demonstrates that, by using FS-PID controller, the system performances are improved and the system also exhibits stability and smoothness.