Research Of The Design Of Active Micro-vbration Isolation Platform Based On Giant Magnetorstrictive Actuators

With the rapid development of precision mechanical engineering, theprecision instrument sets higher requirements to the stability of theworking environment. Precision instrument is always disturbed bymicro-vibration, the high-frequency vibration can be eliminated by passivevibration isolation, and the multi-DOF low-frequency vibration can beeliminated by active vibration isolation platform.Giant magnetostrictive material is applied widely in the precisionengineering, it possesses features of instant reaction, large strain force,high control precision, but also nonlinearity and hysteresis, which make ithard to do modeling and controlling. The3-DOF micro-vibration activeisolation platform is designed with the aims of large actuatingdisplacement, high load capacity and high efficiency. This paper presentsstatic structure design, structure dimension optimization and dynamicsimulation to the platform, and the realization of the platform prototype.The overall structure and operating principle are established in thefirst part. The Giant Magnetostrictive Actuator, electromagnetic coil andmagnetic path are designed. The statics and mechanical strength of thedisplacement amplifier are checked. The structure of displacement transfercomponent, actuator and platform are confirmed.An actuator and its displacement amplifier optimization design arepresented based on the principle of minimum rate of energy loss. Itsubjects to a proposed design principle of minimum rate of energy lossbased on the electromagnetic and mechanic coupling features from energyinput to output of GMA system. The rate of energy loss is a function of a couple of important structural factors of GMA system.In the chapter of dynamic simulated analysis of platform, a dynamicmodel of single actuator and amplifying structure is proposed andintegrated into the dynamic model of the whole system.The optimizedresults of structure parameters are taken into the dynamic model and thedynamic response before and after optimization are compared, includingdisplacement and current acceleration response under different inputelectric currents and loads. The dynamic performance of platform isanalyzed and the effectiveness of the optimization method is estimatedaccording to this. Modal analysis of the whole platform is carried out andthe first eight order of resonant frequency and modes are identified.The final design drawings of the platform are gained according to themethod above and a prototype is built and tested. The performances ofevery actuator are tested, including stiffness determination of bellevillesprings, best preload adjustment and assembly reliability.The wholeplatform machine is assmebled and the output responses are tested, andthey are compared with the dynamic analysis results.In the end, the study contents of whole paper are summarized,meanwhile the shortcomings and insufficiency and the futureimprovements and prospectives of the research are discussed.