Collision-Free Trajectory Planning for a 3-DoF Robot with a Passive Joint
Collision-Free Trajectory Planning for a 3-DoF Robot with a Passive Joint
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DOI：
10.1177/02783640022068011
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发表时间：
2000-12
期刊：
影响因子：
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通讯作者：
K. Lynch;N. Shiroma;H. Arai;K. Tanie
中科院分区：
文献类型：
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作者：
K. Lynch;N. Shiroma;H. Arai;K. Tanie
研究了具有被动转动第三关节的三关节机器人在水平面上从一个零速度状态到另一个零速度状态的运动规划问题。这样的机器人在其零速度部分的开放子集上是小时间局部可控的，允许它在这个子集中任意紧密地跟随任何路径。然而，有些路径是机械臂动力学的“首选”，因为它们可以以更高的速度跟随。在本文中，作者描述了一种计算效率高的轨迹规划器，它可以在障碍物之间找到快速、无碰撞的轨迹。该规划器将机器人六维状态空间中可行轨迹的规划问题解耦为在三维位形空间中规划路径并根据机械臂动力学对路径进行时间缩放的计算简单问题。这种解耦是通过速度方向的存在而实现的，速度方向固定在无源连杆框架中，可以以任意速度执行。该规划结果已在实验欠驱动机械臂上实现。据作者所知，这是第一个实现无碰撞运动规划算法的机械手受二阶非完整约束。
This paper studies motion planning from one zero-velocity state to another for a three-joint robot in a horizontal plane with a passive revolute third joint. Such a robot is small-time locally controllable on an open subset of its zero-velocity section, allowing it to follow any path in this subset arbitrarily closely. However, some paths are “preferred” by the dynamics of the manipulator in that they can be followed at higher speeds. In this paper, the authors describe a computationally efficient trajectory planner that finds fast, collision-free trajectories among obstacles. The planner decouples the problem of planning feasible trajectories in the robot’s six-dimensional state space into the computationally simpler problems of planning paths in the three-dimensional configuration space and time scaling the paths according to the manipulator dynamics. This decoupling is made possible by the existence of velocity directions, fixed in the passive link frame, which can be executed at arbitrary speeds. Results of the planner have been implemented on an experimental underactuated manipulator. To the authors’ knowledge, it is the first implementation of a collision-free motion-planning algorithm for a manipulator subject to a second-order nonholonomic constraint.