On the interaction of temperature-sensing, Shape Memory Alloy dynamics, and control design for a bending actuator

Temperature based control of Shape Memory Alloys faces difficulties in the determination of the actual material temperature profiles due to the typically small geometrical characteristics and possible high rates of excitation. Under such operating conditions, the expected hysteretic response can be transformed into a temperature rate-dependent one, with peculiar response characteristics. The intricacies of temperature sensing on a thin-wire SMA-actuator are coupled with a control-relevant model to enable the application of a sliding-mode controller. Experimental studies are used to validate the controlled system´s performance.