Development And Experiment Of Lower Computer In Non-ciroular Holes Precision Boring CNC,Based On Giant Magnetostrictive Actuator

Giant Magnetostrictive Material, which has large magnetostrictive strain, quick responding, output force and reliability, is widely used in precision machining, precision instruments, vibration control and so on.Piston is one of the most important parts of engine and its performance affects the performance of the engine, even the power system directly. The non-cylindrical holes of a piston can remarkable increase its using life. Due to the particularity of non-cylindrical holes of a piston, and the processing problem appeared in non-clindrical holes precision machining. In order to solve this problem, a non-circular holes precision boring system is proposed based on Giant Magnetostrictive Actuator, to realize the non-cylindrical holes precision machining. For above, this dissertation focuses on the development and experiment of lower computer of non-circular holes precision boring system.By literature search, the dissertation summarized and analyzed the current domestic and abroad researches in Giant Magnetostrictive Actuator and NC system for maching non-circular hole. Based on the summary, the main research work of this dissertation is made.Then, after deeply understanding the characteristic of controled objective and construction of the precision boring system for non-circular pin holes, based on the intelligent boring bar embedded GMM which is developed by our own, this section mainly develops the lower computer of the whole CNC system. The section includes the hardware design and software program of control system.The details on hardware design of the control system are selection of CPU for lower computer, design and make the peripheral circuit including dual-D/A convert circuit base on SPI protocol, process circuit for analog signal and isolating circuit for digital signal, design the tool setting contruction and its circuit, optimized the electrical control circuit of boring machine. The details on software program are the exploitation of the software contruction for this control system, design and program the detection algorithm of boring tool nose’s displacement and coordinate, design and program the close-loop feedback control algorithm base on PID and feed-forward compensation by inverse model and other program work for detail parts such as system initializer, SCI communication, SPI communication and A/D convertion program.Finally, chapter5lays out the experiment of the key parts and the close-loop feedback contrl, indicates the validity of the lower computer for maching typical non-circular holes.