Experimental study on synchronous detection of output force in a self-sensing giant magnetostrictive actuator

This paper systematically investigates the real-time detection of static and dynamic output forces by a self-sensing giant magnetostrictive actuator (SSGMA). The online stiffness of the actuator is perceived as the sensing signal according to the ΔE effect of Terfenol-D. Numerical simulations are carried out to analyze the effects of the driving magnetic field and the hysteresis caused by magneto-mechanical coupling on the performance of self-sensing output force. Then the prototype is fabricated and tested to verify the self-sensing characteristics of SSGMA for the output force. The noise density of prototype is tested to be below 56.92 nV √Hz⁻¹. The experimental results illustrate that SSGMA has a self-detection sensitivity of 0.47 mV N⁻¹ for a static force with an amplitude of nearly 120 N. The SSGMA is able to synchronize the tracking of quasi-static and low-frequency dynamic output forces, respectively. The hereby proposed SSGMA further broadens the application scenario of precision actuation systems by synchronizing the detection and control of the output force without requiring external sensors.