Modeling and simulation of bias-type shape memory alloy actuator system

In order to obtain a control system of bias-type shape memory alloy (SMA) actuator with faster response speed and higher precision, a thermodynamic hysteresis model of bias-type SMA actuators based on the one-dimensional constitutive laws developed by Kanaka-Liang is presented. In allusion to the nonlinearity of inherent hysteresis of SMA, a fuzzy-tuned-PID controller is designed by combining the advantages of proportional-integral-derivative (PID) controller and fuzzy controller, and the simulation model of bias-type SMA actuator with the fuzzy-tuned-PID controller is developed. Results of simulation show that the fuzzy-tuned-PID controller has the advantages of faster response speed, smaller overshoot and better adaptability than PID controller and fuzzy controller. The fuzzy-tuned-PID controller can satisfy the demands of bias-type SMA actuator on control accuracy.