基于凸轮机构的变刚度仿生柔性关节设计与分析

Design and analysis of variable stiffness bionic flexible joint based on cam mechanism

为满足足式机器人跑跳等动态运动对关节柔性及其变刚度特性的迫切要求,借鉴生物关节柔性特征与主被动刚度调节机理,创新地提出了一种基于凸轮机构的新型变刚度仿生柔性关节。基于关节刚度特性分析,构建了关节整体刚度模型,并针对影响关节刚度特性的各结构参数开展了系统优化设计,研制出了一款紧凑型高集成度关节样机。关节样机性能实验结果表明,基于凸轮机构的变刚度仿生柔性关节具备理想的关节输出力矩与刚度调节范围,可通过关节固有刚度特性与动态刚度特性的主被动融合控制,实现关节瞬时刚度的动态非线性精确调节,能够满足机器人动态运动对关节柔性与刚度的需求。

In order to meet the urgent requirements for joint flexibility and variable stiffness characteristics in the dynamic motions of legged robot,such as running and jumping,inspired by the flexible features and active-passive stiffness adjustment mechanism of biological joints,a new type of variable stiffness bionic flexible joint based on cam mechanism was proposed innovatively.Based on the analysis of the joint stiffness characteristics,a joint integral stiffness model was constructed.Then,the joint structural parameters affecting its stiffness characteristics were designed optimally and systematically,and a compact highly integrated joint prototype was developed.The joint prototype performance experiment results show that the variable stiffness bionic flexible joint based on cam mechanism has desired joint output torque and stiffness adjustment range.Through the active-passive fusion control of joint intrinsic and dynamic stiffness characteristics,the nonlinear and accurate adjustment of joint instantaneous stiffness is achieved dynamically,which meets the requirements for joint flexibility and stiffness of robot dynamic movement.