Study On Cylindrical Capacitive Sensors For Monitoring Rotation Error Of High Precision Spindle

Ultra-precision machining technology has very important and wide applications in many high-tech fields such as precision machinery, automobile, aerospace, IC manufacturing and microelectronics etc. High-precision spindle is the core component to achieve ultra-precision machining. In recent years, with the continuous development of ultra-precision machining, more strict requirements for roration error of high precision spindle were put forward. Carrying out research on rotation error monitoring for high precision spindle has a great and far-reaching significance in promoting our national high technology industries such as advanced manufacturing, ultra-precision machining and national military industry and so on.Based on the review of domestic and international research on rotation error monitoring methods and devices for high precision spindle, a cylindrical capacitive sensor(CCS) based on the capacitive displacement measurement principle was designed for multi-degree freedom of rotation error monitoring. Fringe effect of capacitive sensor was analyzed detailly, measuring principle of multi-degree freedom for cylindrical capacitive displacement measurement was studied intensively. Simulation analysis was done for using CCS to measure rotation error for high precision spindle, finally experiments were carried out to verify the simulation results through experimental platform of CCS.Specific content of each chapter are as follows:In the first chapter, widespread use of precision machining technology in various areas of industry and rotation error of high precision spindle introduced firstly. Then the research status of monitoring rotation error for high precision spindle was stated. Finally, research purpose, research meaning and main research contents of the thesis were proposed.In the second chapter, the principle of fringe effect for capacitive sensor was studied, several methods for reducing the fringe effect were recommended. Then reducing effect of these methods was analyzed with the simulation results carried out by Ansoft Maxwell software.In the third chapter, the type, structure and charcateristics of CCS were instroduced. Then theory of using CCS for monitoring rotation error was analyzed. Finally, monitoring principle of CCS sensor for rotation error was simulated by Ansoft Maxwell to verify the feasibility of using CCS for rotation error monitoring.In the fourth chapter, structure of the experiment system for simulation of monitoring rotation error measurement with CCS were designed, including electrodes of CCS and some auxiliary device. The detection circuit was analyzed and designed detailedly. Finally, the interference factors for the circuit were analyzed, and corresponding anti-interference methods were taken in design.In the fifth chapter, the construction of experiment system for CCS was introduced, then stability of the signal in and signal out of the circuit were both tested respectively. Finally, related experiments of monitoring rotation error using CCS for high precision spindle were conducted, and the result were comparatively analyzed with the result got from simulation.In the sixth chapter, the research work was summarized, and subsequent research work was put forward.