改进人工势场的手术机器人位姿规划

Pose planning for surgical robot with improved artificial potential field method

中文关键词  避障  路径规划  手术机器人  人工势场  自适应步长  局部极小值

英文关键词  obstacle avoidance  path planning  surgical robots  artificial potential field  adaptive step size  local minimum

中文摘要

      运动避障与路径规划是手术机器人自动化手术中重要的技术环节, 为机器人手术提供了良好的术中安全 性及准确性. 本研究针对上述两关键技术, 提出改进人工势场的手术机器人位姿规划算法, 首先, 通过对引力函数进 行改进, 在不求取运动学逆解的情况下, 能够准确驱动机械臂到达指定位姿; 接着, 利用快速凸包算法将障碍物凸体 化, 通过Gilbert Johnson Keerthi (GJK)算法计算障碍物与机械臂连杆等效圆柱面之间的最近距离, 使避障距离更加 准确; 然后, 通过自适应步长, 使机械臂运动更加平稳快速; 最后, 引入动态引力常数, 使机械臂具有逃离局部极小 值的能力. 实验结果表明, 本研究能够让机器人在避障情况下平稳快速到达规划位姿, 并在陷入局部极小值时逃逸, 为未来医疗机器人在自动化手术方面提供了新思路.

英文摘要

      Motion obstacle avoidance and path planning are very important technical links in automated surgery of surgical robots, which provide good intraoperative safety and accuracy for robotic surgery. Aiming at the above two key technologies, a pose planning algorithm of surgical robot with improved artificial potential field is proposed. Firstly, by improving the gravitational function, the robot can be accurately driven to the specified pose without obtaining the inverse kinematics solution. Secondly, the fast convex hull algorithm is used to make the obstacle convexification, and the closest distance between the obstacle and the equivalent cylindrical surface of the links are calculated by the Gilbert Johnson Keerthi (GJK) algorithm, so that the obstacle avoidance distance is more accurate. Thirdly, the adaptive step size is adopted to make the movement of the robot more stable and faster. Finally, a dynamic gravitational constant is proposed to enable the robot to escape from the local minimum. The experimental results show that the research can make the robot smoothly and quickly reach the planned pose while avoiding obstacles, and escape when falling into the local minimum, which provides new ideas for future medical robots in automated surgery.