基于动作捕捉技术对仿人机器人运动学分析与步态仿真

Kinematics Analysis of Humanoid Robot based on Motion Capture Technology and Gait Simulation

以人类的构造为原型,基于仿生学的角度,设计了一种下肢单腿7自由度的仿人机器人。通过三维光学动作捕捉系统采集人体正常行走时的运动位置坐标,分析数据,获取人体步态行走时的关节角度及下肢各关节力矩变化规律;建立了下肢7自由度运动学模型并进行逆运动学分析,求解出下肢各关节角度的变化情况,并根据步态规划求解出仿人机器人步行运动过程中下肢各关节转动角度;在UG环境中建立下肢7自由度的仿人机器人三维模型,并利用多体动力学软件Adams进行动力学仿真,结合步态运动规划求解出的角度变化情况对仿真参数进行设置,通过虚拟样机完成仿人机器人的步态行走,并将仿真数据和动作捕捉实验获取的数据结果进行对比。研究结果显示,仿人机器人能够实现稳定的步态行走,确认了整体建模思路、运动学分析以及动力学仿真的准确性。以实验结果为基准,仿真所获得的髋关节和膝关节力矩值相对于实验值的相对误差分别为6.7%和9.6%,均在合理的范围内,为仿人机器人结构设计和电机选型提供了依据。

Based on the human structure as the prototype,a humanoid robot with a lower limb and 7 de⁃grees of freedom is designed based on bionics.The motion coordinates of human body during normal walking are collected through the three-dimensional optical motion capture system,and the joint angle and the variation rule of the moment of each lower extremity joint during walking are obtained by analyzing the data.A 7-degree-of freedom kinematics model of the lower extremity is established and inverse kinematics analysis is carried out to solve the variation of the lower extremity joint angles.According to the gait programming,the rotation angles of the lower extremity joints during the humanoid robot walking are solved.In the lower extremity in UG environ⁃ment,the 3D model of 7 DOF humanoid robot is established,and the dynamics simulation is carried out by us⁃ing multi-body dynamics software Adams,combining with the gait motion planning from the angle of the chang⁃ing situation to set the simulation parameters,through virtual prototype humanoid robot gait,and the simulation data and the data results from the motion capture experimental are compared.Research results show,the human⁃oid robot can achieve stable walking gait,the overall accuracy of the modeling ideas,analysis of kinematics and dynamics simulation is confirmed.Based on the results of the experiment simulation for hip and knee torque val⁃ue compared with the experimental value of relative error of 6.7% and 9.6% respectively in a reasonable scope,the basis for the humanoid robot structure design and motor selection is provided.