Study on control strategy of rotating actuator made by magnetically shape memory alloy

Based on the operation principle of linear actuator of magnetically controlled shape memory alloy (MSMA), two kinds of rotating MSMA actuator are introduced in this paper. The operation principle, structure and control strategy are discussed. The expressions of displacement and rotating speed are derived. The relationship between control magnetic field and permeability of the MSMA are analyzed. Based on the magnetic field analysis, two prototype rotating MSMA actuators are designed and built. The tested speed characteristics of the prototypes with different structure and control strategy are compared. The experimental results show that the rotating speed can be controlled by changing the amplitude and frequency of the excitation current.