Identification method and compensation
control for hysteretic nonlinear systems
YANG Dan, WANG Xiangjiang
(School of Mechanical Engineering, Nanhua University, Hengyang 421001, China)
Abstract: Aiming at the hysteresis nonlinearity characteristics of smart materials, hysteretic system was established by analyzing the hysteresis nonlinearity characteristics of smart materials. This system was consisted of two parts in series, including preisach model eliminated the influence of transfer function, and linear transfer function without considering the influence of hysteresis. Then, hysteretic system model was identified by offline and online identification method. Firstly, transfer function parameters were gotten by the least squares offline identification. Then, hysteresis system model of online identification was obtained by using the identification transfer function parameters as initial weight value of the neural network. Finally, the inverse model control system of identification transfer function and the feedforward controller with a PID controller were established to achieve compensating hysteresis nonlinearity of the identification systems. The results indicate that the feasibility of the identification method and the effectiveness of compensating controls are verified by simulation.
Key words: hysteretic systems; offline identification; neural network identification; inverse model controller; feedforward controller with PID controller