并联机床拟合求差补偿方法研究  

Research on Compensating Method Based on Error Fitting for Parallel Machine Tool

作　　者：陈小岗[1,2] 许兆棠[3] 吴海兵[1,2] 吴蒙蒙[1,2] 

机构地区：[1]淮阴工学院江苏省先进制造技术重点实验室,江苏淮安223003 [2]淮阴工学院机械工程学院,江苏淮安223003 [3]淮阴工学院交通工程学院,江苏淮安223003

出　　处：《机械设计与制造》2015年第12期80-83,共4页Machinery Design & Manufacture

基　　金：江苏省高校自然科学研究重大项目--并联机床综合误差解耦及数字化控制算法的研究(12KJA460001)

摘　　要：为提高交叉杆式Stewart型并联机床的加工精度,提出了一种基于误差拟合曲线对刀轨进行修正的补偿方法。在并联机床工作空间内不同高度位置上加工一系列不同直径的圆柱面,测量结果显示,所有圆柱面的投影轮廓均呈现为椭圆形状,且轮廓中心相对于理想圆心位置均沿近似一致的方向发生偏移从而处于第三象限内。针对实际加工中表现出的上述误差的一致性,提出拟合求差补偿方法。首先对加工获得的圆柱面进行离线采样测量,获得若干实际圆周轮廓点及其相对于理想轮廓点的误差;然后对上述采样点的误差进行拟合操作,获得完整轮廓的误差拟合曲线;最后基于该曲线对加工程序进行修正,从而提高加工精度。对阶梯圆柱面的补偿试验结果表明,该方法可有效降低圆柱面表现为椭圆柱面的程度,同时有效降低了圆柱面中心向第三象限的偏移程度,有效提高了并联机床的加工精度。To improve the manufacturing accuracy of cross-linked Stewart type parallel machine tool, a compensating method by adjusting tool path based on error fitting curve is proposed. After a series of cylindrical surfaces with different diameters are manufactured at different positions in the workspace, the results show that all surfaces seem to be elliptic cylindrical and that centers of all surfaces deviate along much the same direction. Based on above-mentioned uniformity of manufacturing error, the compensating method based on error fitting curve is proposed. Firstly, the cylindrical surfaces are measured offline and discretely, then coordinates of real profile points and corresponding errors relative to ideal points are obtained. Secondly, numerical fitting is completed and fttting curve for whole profile is obtained. Finally, tool path for ftne machining is adjusted based on error fitting eurve. The testing results on a stepped cylinder show that the proposed compensating method can improve the roundness and accuracy and induce the deviation of proftle center effectively.

关 键 词：误差 补偿 并联机床 拟合求差 

分 类 号：TH16[机械工程—机械制造及自动化] TP242[自动化与计算机技术—检测技术与自动化装置]