Self-sensing Giant Magnetostrictive Actuator with Real-time Detection of Mechanical Stress

Abstract:
The development of self-sensing actuator is an effective strategy for miniaturizing electromechanical equipment by forming closed-loop control system without external sensor. In this paper, a self-sensing giant magnetostrictive actuator (SSGMA) based on the DeltaE effect that enables real-time detection of mechanical stress is proposed. The self-sensing signal generated by superimposing a set of high-frequency small sensing excitation magnetic fields on low-frequency static or quasi-static driving magnetic fields is used to extract the information of load stress and output displacement. The dynamic model of the SSGMA is derived on the basis of the complete magneto-mechanical-thermal coupling nonlinear constitutive model of giant magnetostrictive material, and then the parameters of the equivalent piezomagnetism equation, the natural frequency and the characteristics of the self-sensing signal are theoretical analysis. The results demonstrate the developed SSGMA has the ability to self-detect load stress in real time while self-sensing the output displacement.