基于分解插补和拐角平滑的机械手轨迹规划

Trajectory Planning of Manipulator Based on Decomposition Interpolation and Corner Smoothing

为了实现工业机械手高速高精度加工的目标,提出一种基于分解插补和可控拐角平滑的轨迹规划方法。对工业机械手关节坐标系插补存在的问题进行研究,分析在工件坐标系中进行轨迹插补的必要性;提出一种基于分解方法的工件坐标系插补方法,通过将位置命令分解到笛卡尔坐标,姿态命令分解到球坐标,实现工作空间中的轨迹插补,从而生成高精度线性轨迹;其次,提出一种新的运动学可控拐角平滑策略,通过在关节空间的拐角处使用3段式恒定加加速度曲线来生成平滑的轨迹,可通过改变拐角持续时间来控制由此产生的拐角误差;最后,在6DOF机械手上进行了多段刀具路径测试。结果表明:文中方法能够在3.886 s内以0.01 mm的误差有效地实现刀具的线性运动,并在0.5 mm的自定义公差范围内生成每个拐角处的平滑轨迹,从而实现机械手的高速、高精度加工。

In order to achieve the goal of high-speed and high-precision machining of industrial manipulator,a trajectory planning method based on decomposition interpolation and controllable corner smoothing was proposed.The problems existing in the joint coordinate system interpolation of industrial manipulator were studied,and the necessity of trajectory interpolation in workpiece coordinate system was analyzed.Then,a workpiece coordinate interpolation method based on decomposition method was proposed.The position command was decomposed into Cartesian coordinates and the attitude command was decomposed into spherical coordinates to realize trajectory interpolation in the workspace and high-precision linear trajectory was generated.A new kinematic controllable corner smoothing strategy was proposed to generate a smooth trajectory by using a 3-segment constant acceleration curve at the corner of the joint space,the resulting corner error could be controlled by changing the corner duration.Finally,a multi-stage tool path test was carried out on a 6DOF manipulator.The research results show that the proposed method can effectively realize the linear motion of the tool within 3.886 s with an error of 0.01 mm,and generate a smooth trajectory at each corner within the self-defined tolerance of 0.5 mm,thus realizing the high-speed and high-precision machining of the manipulator.