Polishing Error Analysis And Compensation Of Complex Surface Based On Polishing Force Controlled

With the development of science and technology,the precision and complexity of new products are getting higher and higher.Because of special requirements of use,some important parts need to be much more complex with many different surfaces spliced.Parts with complex surfaces play an increasingly important role in the medical,aviation,communication and modern industries.In order to get better performance,we need to produce complex surface parts with higher precision.At present,with the development of numerical control technology and computer technology,the machining precision and efficiency of polishing complex surface are becoming higher and higher.In this paper,based on the five axis CNC polishing machine tool,the author adopt the polishing method of force control to control the polishing process and analyze the influence of machine tool error and polishing profile on the polishing quality of complex surface.And the author improved the polishing quality of complex surface by compensating the positioning error of the machine tool and optimizing the profile of the polishing processing.The machine tool error mainly affects relative positioning of the polishing head and the workpiece and to adopt the homogeneous coordinate transformation method and the theory of multi-body system can obtain the comprehensive error model of the machine tool.Through a laser interferometer,the error of the machine tool is predicted and compensated by the compensation module of the machine tool control system and the error of the machine tool is detected,and finally it meets the requirements of the experimental machine tool positioning accuracy.To achieve deterministic polishing and obtain appropriate surface roughness and high surface accuracy of the workpiece,the author adopt the method of polishing complex surface based on force control through analyzing the results from polishing force measuring system of the polishing process and meanwhile controlling the polishing process parameters.This method can save the time of repeated detection,and it would make the removal amount correspondingly increase with the polishing pressure becoming larger within the allowable range of the polishing pressure which can improve the efficiency of polishing remarkably.The profile model of the polishing trajectory was obtained by mathematical modeling,and the accuracy of the mathematical model was verified by experiments.The influence of various process parameters on the profile of the polishing trajectory was analyzed by Matlab,and then the polishing parameters of the profile of the ideal polishing trajectory were obtained.With the optimized ideal polishing trajectory profile,the author made workpiece polishing experiments using various polishing pressure and established the relation equation between the polishing removal rate and polishing pressure after precise analysis.The dwell time can be controlled by controlling the feed rate of polishing and achieve the purpose of determined removal.Finally,the author examined the accuracy of the polishing surface after the experiment and found that the surface roughness of the polishing surface was improved compared to the roughness before the profile optimization.