Adaptive parametric interpolation scheme with limited acceleration and jerk values for NC machining
Adaptive parametric interpolation scheme with limited acceleration and jerk values for NC machining
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DOI：
10.1007/s00170-006-0834-6
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发表时间：
2008-03
期刊：
影响因子：
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通讯作者：
R. Xu;Le Xie;Congxin Li;Daoshan Du
中科院分区：
文献类型：
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作者：
R. Xu;Le Xie;Congxin Li;Daoshan Du
在数控加工中，参数插补与传统的直线插补或圆弧插补相比具有许多优点。据报道，在这方面的现有工作已经实现了恒定的进给速度，有限的弦误差和有限的加/减速度在一个周期。然而，由于加速度曲线的突变，过大的加加速度仍然存在，这将导致对机器的冲击以及恶化的表面精度。本文提出了一种考虑机床动态性能的自适应插补方法，并进行了详细的说明。该算法在大部分时间内保持指令进给速度不变，在大曲率区域自适应减小指令进给速度以满足加工精度要求，同时在整个插补过程中将加速度和加加速度限制在机床能力范围内。它确保了高加工精度，消除了过冲/下冲现象，并减少了对机床的机械冲击。并对该系统的实时性能进行了测试，以验证其实际应用。两个非均匀有理B样条（NURBS）曲线插补实验验证了该方法的可行性和优越性。
Parametric interpolation has many advantages over the traditional linear or circular interpolation in computer numerical control (CNC) machining. The existing work in this regard is reported to have achieved constant feedrate, confined chord error and limited acceleration/deceleration in one interpolator. However, the excessive jerk still exists due to abrupt change in acceleration profile, which will cause shock to the machine as well as deteriorate the surface accuracy. In this paper, an adaptive interpolation scheme incorporating machine’s dynamics capability consideration is proposed and illustrated in details. In the proposed algorithm, the commanded feedrate is maintained at most of the time and adaptively reduced in large curvature areas to meet the demand of the machining accuracy requirement, while at the same time, the acceleration and jerk values are limited within the machine’s capabilities during the whole interpolation process. It ensures a high machining accuracy, eliminates the phenomenon of overshoot/undershoot and reduces mechanical shock to the machine tools. The real-time performance of this interpolator is also measured to demonstrate its practical application. Two non-uniform rational B-spline (NURBS) curve interpolation experiments are provided to verify the feasibility and advantages of the proposed scheme.