外骨骼离线参数化上楼梯步态规划

Exoskeleton Off-line Parameterization Stairs-ascending Gait Planning

摘要:

为扩大脊椎损伤患者在外骨骼机器人辅助下的活动范围而不仅仅只是起坐、站立和行走，提出一种离线参数化上楼梯 步态规划算法，该算法基于惯性测量单元检测穿戴者运动意图，基于足底压力传感器计算整个系统的零力矩点（ZMP） 以确 保上楼梯过程的安全性。 该算法根据人体大腿、小腿长度、楼梯高度和宽度等参数规划出关节的最优空间位置轨迹， 然后通 过逆运动学求解关节角度轨迹，该算法可为不同的穿戴者生成适应于不同楼梯尺寸的步态轨迹， 最后 3 名实验者穿戴外骨骼 在楼梯高度 18cm、宽度 26cm 的楼梯上实验，外骨骼按照规划的步态轨迹帮助穿戴者多次完成上楼梯任务，规划的楼梯尺寸 与实际测量的尺寸误差在 2%以内，通过实验验证了该算法的有效性与实用性。

Abstract:

In order to extend the sphere of activities of the spine-injured patients with the assistance of exoskeleton robots, it’s more than just getting up, standing and walking. This study proposes an off-gauge parameterization algorithm for stair-ascending gait planning. The algorithm is based on an inertial measurement unit to detect the motion intention of the wearer. To ensure the safety of the stair-climbing process, the zero-moment point (ZMP) of the entire system is calculated based on the plantar pressure sensor. The algorithm designs the optimal trajectory of the joint spatial position based on parameters such as the length of the thigh and the lower leg, the height and the width of the stairs, then solve the trajectory of the joint angle through inverse kinematics. The algorithm can generate different gait trajectories for different wearers to adapt to different stair dimensions. In the end, three experimenters wear the exoskeleton and walk on a stair with a height of 18cm and a width of 26cm. The exoskeleton helps the wearer complete the task of climbing stairs according to the planned gait trajectory. The experiment verifies the effectiveness and practicability of the algorithm