Adaptive PID controllers with sensitivity specification

This paper presents a new technique of adaptive PID controller with sensitivity specification. On the basis of process input and output data of normal operation in the control loop, the important frequency responses of process are estimated with signal decomposition and Fourier analysis, and then a second-order plus dead-time transform function is identified as well. Finally PID control parameters are calculated to satisfy sensitivity specification. The adaptive procedure of PID controller doesn´t need any prior knowledge of the process and previous controller while the control loop is still in the normal operation. Simulation example is given to show both effectiveness and feasibility of the adaptive PID controller.