Research On Path Controlled Precise Micro Displacement Magnetostrictive Actuator

Vibration-assisted machining (VAM) which based on the actuator made of functional materials combines the precision machining with the small-amplitude tool vibration to improve the machining process. It integrates1D vibration and2D vibration properly to improve the processing quality. Actuators made of functional materials should meet the diversified needs of machining such as responding fast, high mechanical strength, low driving conditions, a little volume, compact form and easy control on the frequency and amplitude of vibration.This study bases on the using demands of actuator for vibration-assisted machining. Permendur is used to be the core material for the actuator. The character of magnetostriction is measured by testing. The structural form and driving methods are analyzed. The four legs driving and hollowed-out interior structure is determined. The concrete structure of precise micro displacement magnetostrictive actuator on controllable path is designed. Based on the structure and using demands of actuator, the relationship between of the input control signal and the instantaneous coordinates of outlet end is built. The end path planning of actuator’s end and control principles are sketched. These provide the necessary theoretical basis for experimental study. The natural frequency, the shape of vibration path and the control of vibration shape are calculated by FEM analysis, which aims at optimizing the structural parameter of actuator and provide the necessary values for experimental study.The testing system of precise micro displacement magnetostrictive actuator on controllable path is set up. Some experimental researches are conducted as follows. The proposed distribution theory of magnetic field is verified by the distribution experiment of magnetic field, which quantizes the distribution of magnetic field. When the outlet end of the actuator is working, the influences of vibration amplitude caused by the three elements of sine signal are verified by control experiment of driving magnetic field. The dynamic vibration performances of the actuator are measured, analyzed and evaluated by controlling the vibration path experiment. The paper proposed on-line adjustment method for the actuator’s vibration path study. Based on the concrete using demands of vibration path, the vibration shape can be adjusted by controlling the input signals.The research work of this thesis is to develop and perfect the structural form and control methods for the actuators providing small-amplitude tool vibration, which contribute to the research and development of the vibration-assisted machining equipments. Theoretical basis and experience accumulation for the development and application of the magnetostrictive actuator are provided. The foundation of application research for magnetostrictive actuator used in vibration-assisted machining is provided. The study of precise micro displacement actuators are in the ascendant. The actuators made of functional material can provide the precise vibration. It is of great importance in meeting the special demands of some engineering and technical field and solving the technical difficulties of the micro-manipulations.