Self-sensing magnetostrictive actuator based on Δ <i>E</i> effect: design, theoretical modeling and experiment
Dongjian Xie, Yikun Yang, Bintang Yang
Abstract
Abstract Giant magnetostrictive material (GMM) has the smart potential to be integrated as a self-sensing actuator. This paper presents a novel self-sensing giant magnetostrictive actuator (SSGMA), by sensing the on-line stiffness of the actuator upon the Δ E effect. A self-sensing signal is generated by superimposing a set of high-frequency small sensing excitation magnetic fields on low-frequency static or quasi-static driving magnetic fields. The fully coupled magneto-elastic-thermal nonlinear constitutive model of GMM is derived, and then the self-sensing response model of the SSGMA based on the nonlinear equivalent piezomagnetic equation is proposed. On the theoretical basis, the influences of magnetic field, prestress and temperature on the Δ E effect, the equivalent piezomagnetic equation parameters and the SSGMA sensing signal are investigated in detail, respectively. Moreover, a prototype of the SSGMA is fabricated and tested for self-sensing performance. The experimental results demonstrate the effectiveness of the theoretical analysis, and further show that the proposed SSGMA achieves self-sensing output displacement within a stroke of nearly 50 μ m, with a sensitivity of 2.49 mV μ m −1 . The self-sensing displacement resolution of the SSGMA by far may reach 63.4 nm after experimental determination. This novel self-sensing actuator with micron-level self-sensing drive capability can be integrated into an external sensorless execution system in the future.