Abstract: A novel pressing and bending flexible magnifying structure for micro-positioning system, which is driven by a giant magnetostrictive material based actuator, is introduced. Inspired by several other micro-displacement magnifying units, the mechanism is designed with a two-dimensional plane structure, which is both easy-manufacture and easy-using. It not only amplifies a micro displacement but also changes the direction of a translation motion by 90°. The parameters of the structure of the bended plate are optimized numerically by finite element analysis. It is observed that the hysteresis in a giant magnetostrictive material (GMM) actuator between the current or the magnetic field input and the output displacement changes with the frequencies of the input signals as well as the loads of the actuator. Two BP-neural networks are adopted to construct the inverse models of the upper and lower branches of the hysteresis loop, separately. And the two inverse models are selected by the input signals in real time control. Simulation results prove the correctness of the neural network based inverses in hysteresis compensations. An experiment setup of GMM based pressing and bending mechanism is developed. Experiments performed on the setup show the effectiveness of the inverse based compensation method for hysteresis with both main and minor loops.

Key words: Giant magnetostrictive material, Hysteresis　Analysis　Compensation control, Pressing and bending amplifying mechanism