Study on giant magnetostrictive microdisplacement actuator having the function of sensing its displacement

摘要

A giant magnetostrictive microdisplacement actuator (GMA), which has the function of sensing its microdisplacement, was developed. A circular membrane-type flexible mechanism was proposed to be the GMA's microdisplacement transfer mechanism, which characterized compact structure, zero friction, no driving gap and self-restoring force. The principle of sensing the GMA's microdisplacement was present based on the circular membrane-type flexible mechanism. The mechanical model was proposed using classical small deflection theory of elastic plate and simulation results showed that the resolution of sensing microdisplacement was about 0.056 /spl mu/m in theory. On basis of these, the strain gauges' distribution on the flexible mechanism was determined. At last, experimental studies on the GMA and its microdisplacement closed loop control system were carried out. The experimental results show that the resolution of sensing microdisplacement is about 0.065 /spl mu/m and the closed-loop control positioning accuracy of GMA is about 0.16 /spl mu/m. From the theoretical analysis and experimental results, the function of sensing microdisplacement is an effective approach actualizing microdisplacement closed-loop control and remarkably improving the positioning accuracy of GMA.