Analysis Of The Static And Dynamic Characteristics Of Ultra-precision Hydrostatic Guideway And Its Control Technology Research

As precision and ultra precision technology affect the development of the Nationaldefense industry and civilian industry directly, all the powerful countries of the worldhave conducted extensive research in the ultra-precision machining and have made a lotof achievements. Ultra-precision machine tools is the primary basis to achieveultra-precision machining. Guide is a key component which largely determines theaccuracy of ultra-precision machine tools, so it is necessary to do some research on theguide of ultra-precision machine tools. Hydrostatic guideway is chose as moving partsaccording to the requirements of high precision and high rigidity in machine design. Asgood static and dynamic characteristics and control performance of the guide are neededin Ultra-precision machine, more researches should be done on the static and dynamiccharacteristics and control technology to improve the performance of the guide.Based on the requirements of the development of ultra-precision diamond lathe,related researches have been done on the static and dynamic characteristics and controltechnology of ultra-precision hydrostatic guideway in this paper.According to the machine design requirements and hydrostatic bearing designmanual, the initial structure and size are determined, based on Fluent software, somesimulation and analysis are made on the static characteristics of single oil chamber,parameters such as film thickness, orifice diameter and depth of the oil chamber areoptimized to get the best structure parameters. According to the optimized structuralparameters, the bearing capacity and stiffness of the guide are calculated, then thestiffness test of the guide is done to verify the correctness of the simulation stiffness,natural frequencies and mode shapes are obtained through Modal analysis usingANSYS.The control system is designed based on the PMAC and IPC，after this the motionmodel of the linear motor is established, the bandwidth of the control system is designedto meet the design requirements, and the optimum PID parameters are gotten bydebugging the model. The impact of load changes on the performance of servo system isstudied, complete the establishment of a two-axis motion model for a circular motionsimulation to calculate the arc contour error.Optimal control parameters are obtained by debugging the control system based onPMAC controller, and minimum resolution of the rail are gotten by micro-displacementexperiments. The laser interferometer is used to measure initial rail positioning accuracyand error compensation is done based on error compensation of PMAC, results showthat the rail positioning accuracy is greatly improved. After the adjustment of theparameters, machining experiments are carried out on hard aluminum, it proves that thecontrol system has good performance and is suited to ultra-precision machining.