Research On The Closed-loop Control System In Non-circular Holes Precision Boring Driven By Giant Magnetostrictive Actuator

Giant Magnetostrictive Material, which has large magnetostrictive strain, quick responding, high energy conversion efficiency, output force and reliability, is widely used in precision machining, precision instruments, vibration control and so on.Non-circular pin hole of the piston has a significant improvement in ameliorating the stress distribution of the piston, increasing its ability to bear the load, extending the service life of piston, as well as the engine performance. The group proposed to embed the Giant Magnetostrictive Material in the boring bar, and developed the giant magnetostrictive smart component driven non-circular hole precision boring system. In order to further improve the machining accuracy, this dissertation improved the existing open-loop control system, take research for the giant magnetostrictive driven non-circular hole precision boring closed-loop control system.Based on literature search, the dissertation summarized the characteristics and engineering application of GMM, and analyzed the research status of Giant Magnetostrictive Actuator precision displacement control method and the rotator radial micro displacement detection method. Then, give a depth understanding of the composition of the magnetostrictive smart component driven non-circular hole precision boring system and the characteristics of the object, based on the existing control system, the closed-loop control system solution based on the radial micro-displacement of the intelligent boring bar was proposed. After that, in order to solve the technical difficulty of the radial micro-displacement direction of the boring bar, the dissertation proposed a detection method using two orthogonal arranged displacement sensor and the spindle encoder and the error analysis and processing method of the detection signal, completed the hardware and software design of closed-loop feedback detection system, and the radial micro-displacement measurement experiments verified the feasibility of the method. On previous basis, the P-I hysteresis model of the object was established through experiments, and its inverse model was solved by numerical method. Then, we used the inverse model feed-forward compensation PID control strategy and tuned the control parameters, completed closed-loop control algorithm design and DSP control system software design. Finally, the step response, location tracking and trajectory tracking comparative experiment of the closed-loop control system indicated the validity of the established the closed-loop control system.