基于非均匀B样条曲线的机器人轨迹过渡算法

针对6自由度工业机器人末端轨迹不光顺、衔接速度慢、运动不平稳的问题,提出了一种基于非均匀B样条曲线的过渡模型和对应规划算法。使用5次非均匀B样条曲线,构建了G^(3)连续的空间轨迹过渡模型;根据轨迹过渡的拐角速度约束以及轨迹长度的相互制约关系,提出了自适应的速度前瞻算法;采用四阶龙格库塔-割线法,实现了样条曲线的插补;最后,利用安川HP20D机器人和Leica激光跟踪仪AT960进行实验,测量机器人末端TCP速度和加速度信息。实验结果表明,该过渡算法提升了多段连续轨迹的衔接速度,减小了速度波动,避免加速度突变,实现了机器人的平稳运动。

Corner Transition Algorithm of Industrial Robot Based on Non-uniform B-Spline Curves

A transition smoothing model and corresponding motion planning algorithm based on non-uniform B-spline curves are proposed,to solve the problems of non-smooth trajectory,low transition speed and unstable motion for the 6-DOF industrial robot.A G³ continuous trajectory transition model with 5th degree non-uniform B-spline is constructed.A new trajectory segment is constructed by splitting the B-spline curve in half and splicing the split curve with the original segment.According to the constraint of the corner velocity of corner transition and the mutual constraint of trajectory length,an adaptive velocity forward-looking algorithm is proposed.The fourth order Runge-Kuta-secant method is used to calculate the B-spline curve parameters.To examine the algorithms,an experiment is conducted to measure the speed and acceleration curve of robot by using Yaskawa robot HP20F and Leica laser tracker AT960.The experimental results show that the transition smoothing model improves transition speed for multi trajectories,reduces speed fluctuation,avoids acceleration jumping,achieves the aim of smoothing the movement of robots.