仿生爬树机器人髋关节运动精度可靠性分析与优化

Optimization and Reliability Analysis on Kinematic Accuracy of The Bionic Tree-climbing Robot Hip Joint

以一种非对称空间两自由度并联机构作为仿生爬树机器人的髋关节,能够实现机器人机构沿树干爬升及抱树的复合动作,以此仿生爬树机器人的髋关节为研究对象,基于一阶泰勒展开,建立了包含髋关节机构杆长误差因素、铰链间隙误差因素和机构输入误差因素在内的机构位姿误差数学模型,给定机构参数后,基于所建立误差数学模型,运用蒙特卡罗法得到了髋关节机构运动可靠度,进一步分析了不同误差因素对机构可靠度影响,以及同一误差因素对机构不同方向运动可靠度的影响,并分析了此算例中机构可靠度与机构输入参数之间的关系,最后基于对机构可靠性分析,应用线性加权法对仿生爬树机器人的髋关节机构参数进行了多目标优化设计。

A spatial asymmetric 2-DOF parallel mechanism is used as hip joint of the bionic tree-climbing robot, which can realize the robot climb along the trunk and hug the tree.The hip joint of the bionic tree-climbing robot is investigated in this paper.Based on the first order Taylor approach,considering the error factors such as the length error of the rod,the error factor of the hinge gap and the input error of the hip joint mechanism,the error model is presented.After the parameters of the mechanism are given,the Monte Carlo method is used to obtain the reliability of the hip joint mechanism.The influence of different error factors on reliability of the mechanism and the influence of the same error factors on the reliability of different directions are analyzed,and the relationship between the reliability and the input parameters of the mechanism are analyzed.Based on reliability of kinematic accuracy,multi-objective optimization design for the bionic tree-climbing robot hip joint mechanism parameters is carried out by linear weighting method.