基于曲线插补的多轴联动交叉耦合控制方法

Multi-axis cross-coupled control approach based on curve interpolation

针对高精度轮廓跟踪需要,将曲线插补和交叉耦合控制器结合起来进行研究。在每个采样周期根据各轴反馈的实际刀具位置与插补缓冲区中存储的一定数量的插补点,研究了一种"三点圆弧法"轮廓误差计算模型,并研究了轮廓误差补偿修正量计算及分配方法。在数控试验台上跟踪一段三次非均匀有理B样条轮廓曲线,对比试验表明,所提出的基于曲线插补的轮廓误差交叉耦合控制方法能够有效减小轮廓误差,获得更高轮廓精度。

Aiming at the tracking demand of high precision contour,the cross-coupled controller integrated with curve interpolation was studied.According to the real cutter positions from each axis feedback and the interpolation dots stored in the interpolation buffer in every sampling period,a ＂three-point arc approach＂ contour error computing model was developed.Moreover,the contour error compensated correction quantity computation and distribution approach was put forward.A cubic Non-Uniform Rational B-Spline Curve（NURBS） profile curve on the numerial control experiment table was tracked.The experiment results showed that the developed contour error cross-coupled control approach based on curve interpolation could effectively reduce contour error and obtain satisfactory contour precision.