The Double Magnetic Device’s Improved Design Of Embedded GMM Micro-Feed Mechanism And The Research Of Driving Performance

The non-cylinder pin hole of piston can effectively reduce fatigue wear and oil adhesion,raise the piston performance and lifetime, but it’s difficult to manufacture in batch. Therefore,according to the actual demand of non-cylinder pin hole of piston, the article does the research on the dual excitation device design improvements and driving performance superposition research of the embedded GMA actuator, basing on the Giant Magnetostrictive Material (GMM),which has the characteristic of high frequency and high actuating precision.The dual excitation coil and constant current source are the core of the device, which are components to convert the electric and magnetic, Their quality decide the radial displacement at the end of the boring bar and precision. But the existing method to design the dual excitation coil does not consider the mutual inductance, capacitance and the uniformity of magnetic field.In the meantime, The output of the existing constant-current has the problem of large ripple current, high harmonic and reliability. Therefore, this article does the research on the dual excitation device design improvements and driving performance superposition research of the embedded GMA actuator.In order to establish the improved method of dual excitation coil, Firstly, build up and solve the coil’s model which bases on the existing design method, then analyze and come to the conclusion that the existing design method doesn’t take into account of the mutual inductance,distributed capacitance and magnetic field uniformity. Secondly, do the research on influence of the coil winding process, choose the right coil winding process which has the smaller mutual inductance and distributed capacitance under the same number of turns, then take their influence as constraints when set up the improved design method of dual excitation coil, aiming at producing the maximum magnetic induction intensity, solve the improved model. Thirdly,contrast the two method solving and simulation result as the following aspects: low frequency single coil,high frequency single coil,high frequency dual coils,come to the conclusion that the improving desiged coil increases by 2.6%, 7.1%, 6.6% and 69.2%, 41.8%, 45.7% in maximum magnetic induction intensity and evenness. Then manufacture the two kinds of coils under two design methods, test and contrast their electromagnetic performance, come to the conclusion that the improving desiged coil increases by 10.0%, 11.9%, 9.3% and 5.6% in maximum driving displacement. Finally, verify the effectiveness of proposed improved method.In order to establish the improved method of constant current source, Firstly, analyze the existing method, come to the conclusion that it has the problems of saturation voltage, ripple current,high harmonic,MOSFET tube’s high temperature,then do the analysis of the improved power amplifier circuit module, design the LCCR filter module, overcome saturation module,MOSFET tube heat dissipation module and over temperature protection, simulate and contrast the results of the improved circuit under different driving frequencies and load, test the performance of the circuit, come to the conclusion that the improved method increases by 71.3%and 55.9% in maximum ripple. The stable temperature of the MOSFET deceases by 35.9%, The maximum output voltage increases by 28.9%. Finally, verify the effectiveness of proposed improved method.After establishing and testing the improved design, in order to improve the radial displacement at the end of the boring bar drive control precision, analyze the improved and unimproved system’s performance which is in the state of the open loop feed-forward control,Firstly , build up the experimental test platform, then base on the modified P-I model and combine with the experimental method to identify model parameters. Test and come to the conclusion that the model accuracy of the coil which is designed by improved and unimproved method is 0.3% and 0.6%. Secondly, do the test of the tracing performance, position control accuracy, the typical special-shaped pin hole of piston trajectory control accuracy and system’s maximum output performance, According to the result, come to the conclusion that the improved system is the better one and validate the effeteness of the improved design.