Robust position regulation of a shape memory alloy wire actuator

Abstract

This paper presents design and experiment results of active position control of a shape memory alloy (SMA) wire actuator using a sliding mode based robust approach. In this research, an SMA wire was chosen as an actuating element for position control owing to its high recovery stress (gt;500MPa) and tolerance to high strain (up to 5 per cent). To compensate for the inherent non-linearity associated with the SMA, a sliding mode based robust controller was designed and implemented actively to control the position of the SMA wire actuator. Experiments demonstrated the effectiveness of the robust control. For a 12 in long SMA wire actuator, the position can be controlled within 30m.