2013 Volume 133 Issue 8 Pages 786-794
Temperature controllers are used for various industrial machines. Recently, network solutions have become standard services for controllers. Because each mechanical specification is required as a priori information, it is difficult to perform an identification based on the open-loop step response. In this study, an identification method based on closed-loop operating data is proposed. A closed-loop transfer function is estimated from operating data based on the orthonormal properties of Laguerre series. The process model is extracted from the Laguerre model taking dipole into consideration. The extracted process model is replaced with a low order model based on pole-zero cancellation. The characteristics of the thermal process are considered in the proposed method. Simulation and experimental results show that the proposed method is successful in estimating the process model from the closed-loop response data.