Optimal Design of Rotating Actuators Made by Magnetically Controlled Shape Memory Alloy

In order to solve the problem dealing with the shape recovering by using spring and large excitation power of magnetically controlled shape memory alloy (MSMA) actuator, a new rotating MSMA actuator in the differential control way of the two MSMA elements is proposed in this paper. On the basis of permanent magnet bias magnetic field, the rotating speed can be controlled by changing the amplitude and frequency of the excitation current of the controllable magnetic field. The control properties of MSMA material is introduced, the operation principle of rotating MSMA actuator is analyzed, the expressions of displacement and rotating speed are derived. Based on the magnetic field analysis, a differential rotating MSMA actuator prototype is designed and built. The proposed differential MSMA actuator can reduce effectively the volume and control power, improve control accuracy and dynamic response speed because of adopting the optimal design of exciting mode and control method of recovering the deformation of MSMA element.