A METHOD FOR SENSING AND CONTROLLING THE STRAIN INDUCED IN A MAGNETIC SHAPE MEMORY ALLOY ELEMENT AND A MAGNETIC SHAPE MEMORY ALLOY ACTUATOR AND SENSOR

摘要

The present invention relates to a method and system for sensing and controlling the strain induced in a magnetic shape memory alloy element, and to a magnetic shape memory alloy actuator and sensor. The actuating element (5a) is operated by a control unit (10) having an input control signal (6a) and an input signal (7a) representative of the strain of the actuating element, consisting of a magnetic shape memory alloy. The strain of the actuating element (5a) is determined by measuring its internal electrical resistance, and the control of the same is provided by applying a magnetic field across it, having a magnitude corresponding to the input control signal (6a) and the feedback (7a) information, thereby altering the length of said actuating element (5a) to achieve the desired actuation.