Study On Sensing Magnetic Field And Displacement Type Of Giant Magnetostrictive Microdisplacement Actuator And Its Correlative Technology

Precision driving and its control technology are the foundation and one of key technologies in modem manufacturing industry, such as precision and super-precision finishing, micron/nanometer technology and so on. With the development of modem science and technology, precision driving and its control technology are required better properties. The new type of functional material and the working principle are unceasingly used to improve precision driving and its control technology. As a new type of functional material which has been developed in recent years, rare earth-iron giant magnetostrictive materials has many advantages, such as large magnetostriction strain, high coupling coefficient, quick response, high energy density and so on, which make it have good application future in fields of precision driving and microdisplacement Based on the new type of functional material, this paper uses new principles and approaches to study this kind of microdisplacement actuator and its precision driving system. A new way and train of thoughts are provided to study the new type, high property microdisplacement actuator and its precision control system.Starting with causing mechanism of magnetostriction, this paper analyses and discusses the relationship of physical properties of magnetic crystal, deduces thermodynamics equation of the properties of magnetic crystal, such as magnetism, thermal and elasticity. Meanwhile, the characteristics of giant magnetostrictive materials, such as lengthen and shorten, magnetic-mechanical coupling, pressure stress, temperature and so on, are a little more systematically analyzed and elaborated, and corresponding curves and representations are given. The theory foundation is settled for highly effectively and rationally using giant magnetostrictive material.The driving principle of giant magnetostrictive material is studied and analyzed, and the study is centered on the principle of compound driving, which is used in this paper. The phenomena and reasons of hystersis a7nd nonliearity existing in control model and driving approach on account of current, which are universally used at present, are pointed out. According to magnetic medium following the theories, such as ferromagnetics, electromagnetic field, electrodynamics and so on, and linking the characteristics of driving of giant magnetostrictive materials, a control model and driving approach, which one to one correspondence with magnetostriction, are founded. The theory analysis and experimental study demonstrate that the control accuracy of giant magnetostrictive materials can be effectively improved, if using this control model and control approach of giant magnetostriction materials on account of flux density.A sensing magnetic field and displacement type of giant magneostrictive microdisplacement actuator with the functional of sensing driving magnetic field and microdisplacement is developed, and the design theories and approaches being applicable this type of microdisplacement actuator are pointed out: A circular diaphragm type of flexible construction that acts as integration mechanism of microdisplacement transferring and sensing of giant magnetostrictive microdisplacement actuator is adopted, sheet flexure theory of elasticity mechanics and approach of finite element are applied to design and calculate it, corresponding deflection and analytic formula and distribution curve of stress are given, and the specific achieving approaches of measuring principle and magnetic field sensing function of driving field in giant magnetostricitive rod are pointed out The magnetic field sensing function of the actuator is used to practically measure driving magnetic field of actuator and to obtain the relationship of driving magnetic field and coil current, which is also analyzed and studied.In order to decrease heating of driving coil, the structures of electromagnetic circuit and offset magnetic circuit in actuator are carried out design calculation and experimental study, and the shapes of them are optimum designed. The ef...