Identification of nonlinear actuators with time delay and rate saturation using meta-heuristic optimization algorithms

Actuators with rate and amplitude saturations and time delay are natural parts of autonomous systems. Accurate identification of these actuators is a prominent issue in controller design process. Nonlinear behavior and time delay characteristics have caused more complexity in identification. Various references have dealt with control of autonomous systems considering dynamics of actuators; however, the identification topic has not been explored properly. This article illustrates how meta-heuristic optimization techniques can be used to precisely identify such systems. At first, actuator model as a nonlinear system is considered as a combination of saturation elements, linear transfer function and an inserted time delay. Afterward, actuator model is identified using several optimization methods. The proposed scheme is simulated on a hypothetical system and its performance is demonstrated. Then, it is employed in an identification problem of a realistic actuator. The results revealed that the proposed method has appropriate performance in identification of actuators' dynamics.