The Identification of Input-time-delay System Based on Pole-zero Plot

This paper proposes an estimation method for input-time-delay system with a long time constant by COV (COVariance factorization) method with the shift operation. While it is shown that time delay estimation for a system with a short time constant is possible by checking the order of the estimated model according to the shift operation, it is difficult to apply for a system with a long time delay because the orders are hardly changed according the time delay. In this paper, it is shown that the unstable zeros of the estimated model are the key role to estimate the time delay by simulation, and that simultaneous estimation of the time delay and model are possible by checking zeros of the system.