Adaptive delay compensated PID controller by phase margin design

Abstract A continuous-time delay compensated adaptive PID controller for unknown time delay dominant systems is proposed. Smith predictor is employed to reduce the effect of time delay in the closed-loop system and polynomial identification is implemented for the on-line estimation of the system parameters and the on-line tuning of the PID controller is realised by phase margin design. Pretuning of the proposed controller is also presented. The proposed adaptive PID controller has the flexibility to handle both overdamped and underdamped systems. Simulation and experimental results are included to demonstrate the effectiveness of the proposed controller.