Control Characteristics of Shape Memory Alloy Actuator Using Resistance Feedback Control Method

Abstract

The actuators using shape memory alloys can work as an actuator to control or retain positioning without using sensor devices. In this work, a position control model with a biasing mechanism is produced. The produced model is controlled by resistance feedback using the method of setting off-time and can be set and retained at an arbitrary position. The effects of input current, control distance and off-time on positioning characteristics such as dynamic behavior and position stability are investigated. The results show that high input current for heating is effective for shortening the rise and settling times. However, the overshoot increases with increasing input current. When the recovery strain is below 2.5%, the rise and settling velocities increase with increasing control distance. Furthermore, the off-time affects position stability. In the case of short off-time, fine position stability is performed regardless of the values of input current and control distance.