Control Method Research Of Machining Non-cylindrical Bore Based On Giant Magnetostrictive

Piston is a key component of internal combustion engine, and usually its pin-hole has been designed to be non-cylindrical bore with trumpet and oval to improve stress condition and extend the service life. CNC deformation boring bar machining based on giant magnetostrictive material has the features of simple structure, excellent flexibility, high frequency response and high precision machining, so it has practical value and significance to research magnetostrictive process control system of non-cylindrical bore.In chapter 1, research on micro-displacement mechanism and its control system is stated. According to the advantages and problems of magnetostrictive machining of non-cylindrical bore, the significance of this thesis topics are proposed and the main research contents are explained.In chapter 2, with the GMM intelligent component which was designed by author's laboratory, the principle of magnetostrictive machining of non-cylindrical bore has been stated according to non-cylindrical bore geometry characteristics and the characteristics of giant magnetostrictive material. The mathematical model has been established between drive current and the displacement of intelligent component. And the deformation curve between them has been obtained by the experiment.In chapter 3, according to the principle of automatic control, the whole structure and hardware of magnetostrictive process control system of non-cylindrical bore has been designed. The system uses upper machine PC and lower machine DSP to do controlling. And the designing of main module is stated, including DSP driver module, sensor module, linear power amplifier module and so on.In chapter 4, according to the demand analysis, the control software of upper machine has been designed by using LabVIEW programming language on the windows platform. Using the principle of ergonomics to design the main program interface, and using circular interpolation of uniform angle to pre-process the data, and developed the communication protocol based on RS232 to realize the interaction between pc and dsp. Finally, the whole software structure of lower machine is designed.In chapter 5, contrary to the influence of hysteresis non-linear, the Preisach module of GMM intelligent component has been established which also verified according to doing experiments. Then did some experiments about feedforward compensation based on Preisach module and PID feedback control.In chapter 6, main work in the dissertation is summarized and further research work is put forward.