机械臂式治疗床的水平避障研究

Study on the horizontal obstacle avoidance of mechanical arm therapeutic bed

重离子放射治疗对机械臂式治疗床摆位引导精度和精确定位精度有特殊要求,针对放射治疗室工作空间内的障碍物对机械臂式治疗床的运动干涉,提出了一种基于人工势场法的避障路径规划方法。首先根据治疗室的平面模型,结合D-H表示法建立碰撞干涉模型;然后利用人工势场法规划出治疗床末端执行器的避障路径,并根据每一处路径点的坐标利用逆运动学解,计算出每一组关节角;最后进行了避障仿真验证。仿真表明,该方法可以实时有效地避开障碍物,平稳到达目标点,适合治疗床的运动控制要求。

The special requirements of heavy ion radiation therapy for the degree of the positioning guide and accurate location of the mechanical arm therapeutic bed are presented. For the problem of the movement interference of the mechanical arm therapeutic bed against the obstacles in the workspace of the radiation therapeutic room, a method of obstacle avoidance path planning based on artificial potential field is presented. Firstly, the collision interference model is established according to the plane model in the treatment room and D-H representation. Then, the artificial potential field method is used to draw the obstacle avoidance path of the end effector of the therapeutic bed, and according to the coordinates of each path point, the joint angles of each set are simulated by inverse kinematics. Finally, simulation of obstacle avoidance is carried out. The results show that the method can avoid obstacles effectively and reach the target point in time, so it is suitable for the motion control of the therapeutic bed.