Design and experimental performance of an inertial giant magnetostrictive linear actuator

Abstract

In order to meet the requirements of large stroke and high precision linear displacement, an inertial impact type giant magnetostrictive linear actuator was designed according to the principle of the inchworm motion. The stepwise cumulative displacement motion can be realized by applying a sawtooth wave signal to the excitation coil. The superimposed flexible hinge effectively improves the force of the system. The equivalent stiffness is calculated by simplifying the flexible hinge into a cantilever beam, and the strength of the flexible hinge is checked, the modal analysis is carried out. The displacement model of inertial actuator is established according to voltage law, magnetoresistance theory, linear piezomagnetic model and dynamic theory. The experimental platform is built and the prototype is designed for test. The experimental and simulation results show that the operating voltage range of the inertial actuator is 3 V–9 V, the maximum operating frequency is 60 Hz, the minimum and maximum single step displacement are 2.41 μm and 7.49 μm, and the maximum speed is 449.4 μm/s. The displacement output is stable, the maximum relative error of the single step displacement is 3.97 %. In the working voltage range, the maximum error between the simulated and experimental values is 4.84 %. And the maximum error between the simulated and experimental values is 2.96 % in the working frequency range. So the design scheme and the displacement model have certain reference significance for the application of large stroke actuator.