摘要
Error modelling and compensating technology is an effective method to improve the processing precision.The position and orientation deviation of workpiece is caused by the fixing and manufacturing errors of the fixture.How to reduce the position and orientation deviation of workpiece has become a technical problem of improving the processing quality of workpiece.In order to increase machining accuracy,an implementation scheme of fixture system comprehensive errors（FSCE） compensation is proposed.A FSCE parameter model is established by analyzing the influence of contact points on the position and orientation of workpiece.Meanwhile,a parameter identification method for FSCE parameter model is presented by using the 3-2-1 deterministic positioning fixture,which determines the model parameters.Moreover,a FSCE compensation model is formulated to study the compensation value of the cutting position.By using RenishawOMP60 Probe and combining vertical machining centre（SKVH850） equipment with SKY2001 Open CNC System,on-machine verification system（OMVS） is built to measure FSCE successfully.The processing error can be reduced by analyzing the cutting position of the tool with the homogeneous transformation of space coordinate system.Finally,the compensation experiment of real time errors is conducted,and the cylindricality and perpendicularity errors of hole surface are reduced by 30.77% and 28.57%,respectively.This paper provides a new way of realizing the compensation of FCSE,which can improve the machining accuracy of workpiece largely.
Error modelling and compensating technology is an effective method to improve the processing precision.The position and orientation deviation of workpiece is caused by the fixing and manufacturing errors of the fixture.How to reduce the position and orientation deviation of workpiece has become a technical problem of improving the processing quality of workpiece.In order to increase machining accuracy,an implementation scheme of fixture system comprehensive errors（FSCE） compensation is proposed.A FSCE parameter model is established by analyzing the influence of contact points on the position and orientation of workpiece.Meanwhile,a parameter identification method for FSCE parameter model is presented by using the 3-2-1 deterministic positioning fixture,which determines the model parameters.Moreover,a FSCE compensation model is formulated to study the compensation value of the cutting position.By using RenishawOMP60 Probe and combining vertical machining centre（SKVH850） equipment with SKY2001 Open CNC System,on-machine verification system（OMVS） is built to measure FSCE successfully.The processing error can be reduced by analyzing the cutting position of the tool with the homogeneous transformation of space coordinate system.Finally,the compensation experiment of real time errors is conducted,and the cylindricality and perpendicularity errors of hole surface are reduced by 30.77% and 28.57%,respectively.This paper provides a new way of realizing the compensation of FCSE,which can improve the machining accuracy of workpiece largely.
基金
supported by National Natural Science Foundation of China (Grant No. 50975200)
National Key Technologies R & D Programmer of China (Grant No. 2009ZX04014-021)
作者简介
Corresponding author:HE Gaiyun,born in 1965,is currently a professor at Tianjin University,China.She received her PhD degree from Tianjin University,China,in 2006.Her research interests include modem manufacturing quality control,evaluation methods of geometric errors and CAD/CAM/CAI integration technology.Tel:+86-22-27402324,E-mail:hegaiyun@tju.edu.cn;YANG Baolong,born in 1986,is currently a master candidate at Tianjin Key Laboratory for Advanced Manufacturing Technology and Equipment,Tianjin University,China.His research interest is modem manufacturing quality control.E-mail:yblong@yahoo.cn;DING Baihui,born in 1976,is currently a lecturer at Tianjin University,China.She received her PhD degree from Tianjin University,China,in 2008.Her research interests include modem manufacturing quality control and CAD/CAM/CAI integration technology.E-mail:dingbaihui@tju.edu.cn;JIA Hongyang,born in 1988,is currently a master candidate at School of Mechanical Engineering,Tianjin University,China.His research interest is modem manufacturing quality control.E-mail:hyjia_tju@163.com.
