基于传递矩阵法的足式机器人四连杆腿部机构正向与逆向动力学分析

Forward and Reverse Dynamics Analyses on Four-bar Linkage Leg Mechanism of Legged Robots Based on Transfer Matrix Method

为了保证足式机器人腿部机构的控制准确性与实时性,利用向量代数方法,对足式机器人四连杆腿部机构进行几何运动学分析;根据有限元形函数理论,建立足式机器人四连杆腿部机构典型构件的质量离散方法;在几何运动学分析的基础上,基于力矩平衡原理,分别进行正向与逆向动力学分析;利用线性变换原理并结合传递矩阵法,建立足式机器人四连杆腿部机构正-逆向动力学统一模型,并利用Adams软件建立足式机器人四连杆腿部机构虚拟样机模型,进行正向与逆向动力学仿真实例分析。结果表明,所建立的足式机器人四连杆腿部机构正-逆向动力学统一模型与虚拟样机模型3个油缸力与3个方向足底力的误差分别小于1%与3%,验证了所建立的足式机器人四连杆腿部机构正-逆向动力学统一模型能够精确地求解油缸力与足底力。

To ensure control accuracy and instantaneity of leg mechanism for legged robots,geometric kinematic analysis on four-bar linkage leg mechanism of legged robots was carried out by using vector algebra method.A mass dispersion method for typical bars of four-bar linkage leg mechanism of legged robots was established according to finite element form fu nction theory.On the basis of geometric kinematic analysis and principle of moment balance,forward and reverse dynamic analyses were carried out respectively.A un ified forward-reverse dynamics model for four-bar linkage leg mechanism of legged robots was established by using principle of linear transformation and combining transfer matrix method.A virtual prototype model for four-bar linkage leg mechanism of legged robots was established by using Adams software for example analysis of forward and reverse dynamics simulation.The results show that errors of three cylinder forces and plantar forces in three directional between the established unified forward-reverse dynamics model and the virtual prototype model for four-bar linkage leg mechanism of legged robots are less than 1%and 3%,which verifies that the established unified forward-reverse dynamics model for four-bar linkage leg mechanism of legged robots can accurately solve cylinder force and plantar force.