面向伺服动态特性匹配的轮廓误差补偿控制研究

发布时间：2018-05-01 10:28

本文选题：动态特性匹配 + 轮廓误差　；参考：《机械工程学报》2017年01期

【摘要】：在多轴数控加工中,轮廓误差直接决定零件最终加工精度。交差耦合控制和任务坐标系法通过估计轮廓误差,并设计轮廓跟踪控制器来提高轮廓精度。这两种方法存在大曲率位置轮廓误差估计精度差,轮廓控制增益整定依赖于工程经验等问题。为此,从伺服轴动态特性匹配出发,提出了一种基于轮廓误差精确计算的轮廓误差补偿控制方法。根据足点定义,采用解析方法快速准确计算轮廓误差。将轮廓误差分量分别补偿到各伺服轴的速度环和转矩环,提高各伺服轴动态特性的匹配程度。采用两维和三维NURBS曲线开展轮廓跟踪试验。试验结果表明:所提出的轮廓误差计算方法可以精确求解轮廓误差;所提出的轮廓误差补偿控制方法不需要建立轮廓误差与伺服跟踪误差间的映射关系,且可通过调整控制器增益定量显著减小轮廓误差。
[Abstract]:In multi-axis NC machining, contour error directly determines the final machining accuracy of parts. By estimating contour error and designing contour tracking controller, the contour accuracy can be improved by means of cross-coupling control and task coordinate system method. These two methods have some problems such as poor precision of contour error estimation in large curvature position and dependent on engineering experience for contour control gain tuning. Based on the dynamic characteristic matching of servo shaft, a contours error compensation control method based on accurate calculation of contour error is proposed. According to the definition of foot point, the contour error is calculated quickly and accurately by analytic method. The contour error components are compensated to the speed loop and torque loop of each servo shaft respectively to improve the matching degree of the dynamic characteristics of each servo shaft. Contour tracking experiments were carried out by using two-dimensional and three-dimensional NURBS curves. The experimental results show that the proposed contour error calculation method can accurately solve the contour error, and the proposed contour error compensation control method does not need to establish the mapping relationship between contour error and servo tracking error. The contour error can be significantly reduced by adjusting the gain of the controller.
【作者单位】：华中科技大学数字制造装备与技术国家重点实验室;
【基金】：国家自然科学基金(51405175,51535004,51323009) 中国博士后科学基金(2014M562013,2015T80789)资助项目
【分类号】：TG659

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