超冗余柔性臂在狭小空间内改进RRT算法轨迹规划

Improved RRT Algorithm-based Trajectory Planning Algorithm for Super-redundant Flexible Arms in Tight Spaces

摘要:

为清理变电站联排变压器狭小空间内的异物,设计了一种超冗余多关节机械臂。根据机械臂的运动学特性在机器人工具箱建立了运动学模型,利用正运动学分析了万向节角度和驱动绳长,并利用蒙特卡洛法建立了机器人的工作空间。为缩短轨迹路线、减少随机树点数目,提出了基于改进后的RRT算法的轨迹规划方法,利用贪心算法进行轨迹优化,仿真结果显示路径长度减少20%且规划时间提高60%；利用多阶贝塞尔曲线进行轨迹平滑,降低轨迹路线曲率。改进后的RRT算法可以有效的避障,且轨迹更为精确、曲率较小、处理速度更快,可以快速有效的完成异物清理工作。

Abstract:

To remove foreign objects from a substation interconnection transformer"s limited environment, a super-redundant multi-joint robotic arm was created. The gimbal angle and drive rope length were examined using positive kinematics, the robot"s workspace was established using the Monte Carlo approach, and a kinematic model was established in the robot toolbox based on the kinematic properties of the robotic arm. A trajectory planning approach based on the enhanced RRT algorithm is suggested, and trajectory optimization is carried out using the greedy algorithm in order to shorten the trajectory route and decrease the number of random tree points. The revised RRT algorithm can successfully avoid obstacles, and the trajectory is more precise, has less curvature, and has a faster processing time. It can also successfully and rapidly finish the cleaning of foreign objects.