下肢康复机器人的机械腿误差源判定方法

Error Source Determination Method for Mechanical Leg of Lower Limb Rehabilitation Robot

针对下肢康复机器人加工过程中机械腿存在位姿误差的问题,提出了一种下肢康复机器人机械腿加工安装误差源判定方法。首先,对所设计的坐卧式下肢康复机器人结构进行介绍,包括三自由度串联机械腿及胖瘦可调机架。应用D-H(Denavit-Hartenberg)法,求解了机械腿各关节角度与末端位姿运动学函数关系;考虑到误差来源与刚体连杆传递方程,建立了机械腿末端位姿误差与各连杆运动变量和结构参数误差之间数学关系;运用蒙特卡罗法模拟和分析,实现了可基于机械腿静态位姿精度可靠度的误差源判定,从而为下肢康复机械腿装备生产提供指导,并为纠正患者步态的精确运动奠定理论基础。

Aiming at the problem of pose error in the machining process of lower limb rehabilitation robots,a method to determine the error source of the mechanical leg of a lower limb rehabilitation robot is proposed.Firstly,the mechanism of a sitting/lying lower limb rehabilitation robot is introduced,which includes a series of mechanical legs with three degrees of freedom and an adjustable frame for patients with different body types.The D-H(Denavit-Hartenberg)method is used to solve the kinematic function between the joint angles and the end pose of the mechanical leg.Considering the error source and rigid link transfer equation,the mathematical relation between the end pose error of the mechanical leg and the motion variables as well as the structural parameters error of each link is established.Simulation and analysis through Monte Carlo method are used to determine the error source based on the static pose accuracy reliability of the mechanical leg,so as to provide guidance for the assembly and production of lower limb rehabilitation mechanical legs,and lay a theoretical foundation for correcting the precise movement of patients’gait.