Local Image Based Processing Methodology For Profile Grinding Of Contour Surface

With the rapid development of the manufacturing industry,profile grinding has been widely used in machining the contour curves of the products such as various complex cutting tools and molds.In order to meet the requirements of high precision and rapid processing,it becomes very important to improve the machining accuracy and efficiency of profile grinding.Manual optical detection and compensation of machining errors is a relatively effective method to improve machining accuracy.It has been widely used in traditional optical contour grinding,but there are still some problems to be solved,such as low efficiency,lack of reliability and accuracy.Therefore,based on machine vision technology,an in-situ method to detect and compensate profile error was studied in this paper.Here are the main research contents:(1)The basic principle of profile grinding and the design of the vision system.The basic principle of profile grinding based on machine vision is studied.The digital curve grinding machine is introduced.The composition and calibration method of the vision measuring system of the machine are expounded,which is the foundation for high precision machining.(2)Research on precise positioning method of complex contour curve edges.The research compares different algorithms for image edge extraction,including the pixel level and sub-pixel edge extraction algorithms.Then both simulation method and calibration plate method were proposed for accuracy evaluation of the sub-pixel positioning algorithms of the contour edge.Furthermore,an experiment was designed.The results were analyzed and the uncertainty of the measurement results was evaluated.The results verify the effectiveness of the proposed sub-pixel localization algorithm and accuracy evaluation method.(3)Theoretical and experimental studies on the accuracy evaluation of profile grinding.An overall profile accuracy detection and evaluation method for irregular contours of workpieces is proposed to achieve the insitu evaluation of the contour accuracy of the workpiece.The experiments based on workpieces and calibration plate are designed to verify the validity of the algorithm.(4)In-situ error detection and compensation of profile grinding based on local vision image.The principle and implementation process of on-line error detection are introduced and simulated.The detection efficiency of the algorithm is studied.The experiments are designed and the results show that the error detection and compensation method proposed in this paper can effectively improve the accuracy of profile grinding.