Process identification for an SOPDT model using rectangular pulse input

A new method of process identification for a second-order-plus-dead-time mo del is proposed and tested with two example systems. In the activation of t he example processes for the identification, a rectangular pulse input is a pplied to open loop systems. The model parameters are estimated by minimizi ng sum of modeling errors with the least squares method. The estimation per formance is examined by comparing the output pulse responses from the examp le system and the estimated model. The performance comparison of the propos ed method and two existing techniques indicates that satisfactory parameter estimation is available from the proposed procedure. In addition, the role of sampling time and the shape of input pulse is evaluated and it is found that the sampling time of less than 0.01 minute gives good estimation whil e the shape of input pulse does not affect the estimation performance, Fina lly, the robustness of the estimation in noisy process is proved from the i nvestigation of the performance in the processes having various levels of n oise.