基于改进DMPs的下肢助行机器人步行楼梯的轨迹规划

Trajectory Planning of Lower Limb Walking-Assistant Robot Walking Stairs Based on Improved DMPs

摘要: 为了辅助下肢功能障碍患者实现在不同尺寸楼梯行走，运用改进的动态运动基元(DMPs)结合机器人运动学分析规划下肢助行机器人运动轨迹和步态。首先，基于D-H模型，建立下肢助行机器人末端机构位姿与各关节角度的关系。然后，使用改进DMPs模仿预先采集到的正常人体步行楼梯轨迹曲线，根据楼梯高度和宽度参数修改目标点，泛化后得到适应新场景的轨迹曲线。再运用机器人逆运动学分析，规划出适应于不同尺寸楼梯的下肢助行机器人踝关节和髋关节运动轨迹。经过仿真实验验证，基于改进的DMPs结合逆运动学分析能有效地规划助行机器人运动的步态，使机器人能适应不同参数的楼梯行走。

Abstract: In order to assist patients with lower limb dysfunction to walk on stairs of different sizes, improved dynamic movement primitives (DMPs) combined with robot kinematics analysis were used to plan the trajectory and gait of the lower limb walking-assistant robot. At first, the relationship between the posture of the end mechanism and the angles of each joint was established based on D-H model. Then, the improved DMPs were used to simulate the trajectory curve of normal human walking stairs, and the target points were modified according to the height and width of the stairs. After generalization, the trajectory curve adapted to the new scene was obtained. Then, the trajectory of ankle joint and hip joint of the robot adapted to stairs of different sizes is planned by using inverse kinematics analysis of robot. The simulation results show that the improved DMPs combined with inverse kinematics analysis can effectively plan the gait of the walking aid robot so that the robot can adapt to stair walking with different parameters.