Extended State Observer-Based Retardation Time Estimation for Time-Delay System

This paper proposes a retardation time esti-mation method for a time-delay system. Firstly, a system model is established with input delay. Secondly, based on the time delay model, an extended state observer (ESO) is proposed with the known system dynamics. And, the impact of retardation time can be estimated from the extended state. Thirdly, to estimate the retardation time, a controller with designed signal is proposed. Then, the difference in the con-trol input between the ESO and the system can be estimated from the estimated disturbance, and it is used for the retar-dation time estimation. Eventually, the effectiveness of the proposed method is verified by the simulations. The results show that the retardation time estimation can be estimated accurately. Compared to the differentiator of the state, the retardation time can be obtained from the extended state more easily and accurately.