Recursive estimation of time delay in sampled systems

An identification method based on standard recursive least squares for the estimation of time delay in linear sampled systems is presented. The algorithm relies on the fact that if the continuous time model has a delay or anticipation shorter than one sampling time, then a real negative zero arises in the corresponding sampled system. By inspection of the phase contribution of this zero, the value of the delay is recursively updated. A frequency domain analysis is performed to examine the characteristics of the algorithm. Simulation results illustrate the performances of the time delay estimation algorithm.