基于高阶非均匀有理B样条插补的多轴运动控制方法研究

Research on Multi-axis Motion Control Method Based on High-order Non-uniform Rational B-spline Interpolation

针对传统多轴运动控制系统在作业中存在轨迹转折处不平顺、加速度和加加速度切换不平滑产生变速冲击以及轨迹不能进行局部修改的问题,提出了一种基于高阶非均匀有理B样条插补的多轴运动控制算法。首先,构建五次非均匀有理B样条插补算法,对样条曲线数据进行预处理,根据非均匀有理B样条曲线反算出控制点并生成控制多边形;其次,利用MATLAB构建多轴机械臂和高阶非均匀有理B样条插补算法模型,通过给定型值点进行轨迹规划仿真。仿真结果表明:基于高阶非均匀有理B样条的多轴运动控制插补方法相对于低阶非均匀有理B样条曲线轨迹更圆滑,末端更能高效平稳地到达给定目标点;速度、加速度和加加速度的过渡更加平滑减少机械磨损,从而提高了运动的平稳性;并且该方法还能够对运动轨迹进行局部修改,提升了多轴运动控制的作业质量。

In order to solve the problems of the traditional multi-axis motion control system,such as the irregularity at the turning point of the trajectory,the variable speed impact caused by the unsmooth switching acceleration and jerk,and the problem of being unable to modify part trajectory,a multi-axis motion control method based on high-order non-uniform rational B-spline interpolation is proposed.Firstly,the quintic non-uniform rational B-spline interpolation algorithm is constructed,and the spline data are preprocessed.According to the non-uniform rational B-spline curve,the control points are calculated and the control polygons are generated.Secondly,the multi-axis manipulator and high-order non-uniform rational B-spline interpolation algorithm model is constructed by MATLAB,and the trajectory planning simulation is carried out with given type data points.The simulation results show that the multi-axis motion control interpolation method based on high-order non-uniform rational B-spline curve is more smooth than the low-order non-uniform rational B-spline,and the end can reach the given target point more efficiently and smoothly.The transition of velocity,acceleration and jerk is smoother so that it reduces mechanical wear,thus improving the stationarity of motion.And this method can also modify the trajectory in the running process,improving the operation quality of multi-axis motion control.