并联机床拟合求差补偿方法研究

发布时间：2018-04-14 05:16

本文选题：误差 + 补偿　；参考：《机械设计与制造》2015年12期

【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。
[Abstract]:In order to improve the machining accuracy of cross rod type Stewart parallel machine tool, a compensation method based on error fitting curve is proposed to correct the tool track.A series of cylindrical surfaces with different diameters are machined at different height positions in the workspace of PMT. The measurement results show that the projection profiles of all cylindrical surfaces are elliptical.And the center of the contour moves in the same direction relative to the ideal center and is in the third quadrant.In view of the consistency of the above mentioned errors in practical machining, a fitting method for error compensation is put forward.Firstly, off-line sampling measurement is carried out to obtain some actual circumferential contour points and their errors relative to ideal contour points, and then fitting operation is carried out to obtain the complete contour error fitting curve.Finally, the machining program is modified based on the curve to improve the machining accuracy.The experimental results of step cylinder surface compensation show that this method can effectively reduce the degree of cylinder surface appearing as elliptical cylinder, reduce the shift degree of cylindrical surface center to the third quadrant, and improve the machining accuracy of parallel machine tool.
【作者单位】：淮阴工学院江苏省先进制造技术重点实验室;淮阴工学院机械工程学院;淮阴工学院交通工程学院;
【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)
【分类号】：TG65

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