Application of Shape Memory Alloy Actuators to Control the Displacement of an Adaptive Beam

Abstract

Shape memory alloy (SMA) wire actuators have broad application prospects in many fields. But due to the nonlinearity of inherent hysteresis of SMA, the precise position control system is difficult to be obtained to these kinds of actuators. Therefore, it is significant to research the control technology of SMA wire actuators to extend the application of SMA wire actuators. In the current paper, a shape memory alloy wire actuator is designed to control the displacement of an adaptive beam. The dynamic model of SMA wire actuator is derived based on Brinson’s model and two types of inputs are used to produce different displacements. Then, PID control strategy for the SMA actuators is established and implemented to active control the position. Also, real-time control (RTC) is applied to the SMA wire actuators, which can concurrently generate real-time codes and accelerate the process of simulation. Through the comparison of different amplitudes and frequencies of current inputs, the different control abilities and characteristics to acquire the maximal displacement can be approximately achieved. Significantly, the position can basically remain stable. The results demonstrate the SMA wire actuators can be used to stably control the displacement of the adaptive beam.