四足机器人软硬地面稳定过渡的腿部主动变刚度调节策略  

Active and variable stiffness adjustment strategy for legs of quadruped robot for stable transition between soft and hard ground

作　　者：刘帅 赵慧 刘清宇 LIU Shuai;ZHAO Hui;LIU Qing-yu(Key Laboratory of Metallurgical Equipment and Control(Ministry of Education),Wuhan University of Science and Technology,Wuhan 430081,China;Key Laboratory of Mechanical Transmission and Manufacturing Engineering(Hubei Province,Wuhan University of Science and Technology),Wuhan 430081,China)

机构地区：[1]武汉科技大学冶金装备及其控制教育部重点实验室,武汉430081 [2]武汉科技大学机械传动与制造工程湖北省重点实验室,武汉430081

出　　处：《工程科学学报》2022年第3期420-429,共10页Chinese Journal of Engineering

基　　金：国家自然科学基金资助项目(51805381)。

摘　　要：针对四足机器人在变刚度地面环境下动态行进时易出现姿态不稳定的问题,本文提出了一种机器人腿部主动变刚度实时调节策略,该策略根据机器人着地后的机身和腿部的运动状态实时估计出着地腿和地面的耦合刚度,并将前后腿与地面耦合刚度的差值补偿到相应的着地腿上.该策略能够使机器人着地后迅速适应不同刚度特性的地面,特别是地面刚度相差较大的情况.通过搭建Simulink-SimMechanics仿真平台,对角腿在同一刚度地面和变刚度地面两种不同的着地环境,对仅利用常规姿态反馈控制、腿部主动变刚度调节策略与常规姿态反馈控制联合方式进行了对比实验.结果表明,通过腿部主动变刚度调节策略的作用,四足机器人在软硬地面过渡时实现对机身俯仰角和滚转角的补偿修正,调控效果优于单独通过常规姿态反馈控制.Quadruped bionic robots are favored by development experts because of their broad application prospects,such as interstellar exploration,educational companionship,and social inspections.Quadruped robots were developed and inspired by mammals,which are known to exist in most areas on the earth's land surface.However,quadruped robots cannot achieve such an ideal state due to various reasons.At present,the adaptive problem of quadruped robots under a complex and changeable terrain has made significant progress,as reported in related literature.However,the case of robots that are as flexible as mammals in nature and meet the needs of multi-functional and multi-scenarios are still poorly understood.A quadruped robot is prone to posture instability when dynamically traveling in a ground environment with variable rigidity.This work proposes a real-time adjustment strategy of the active variable stiffness of the legs.This strategy estimates the landing in real time based on the motion state of the fuselage and legs after the robot touches the ground.The coupling stiffness of the legs and the ground and the difference between the coupling stiffness of the front and rear legs and the ground is compensated to the corresponding landing legs.This enables the robot to quickly adapt to the ground with different stiffness characteristics after landing,especially when the ground stiffness differs greatly.The Simulink-SimMechanics simulation platform is established with the diagonal legs on the same stiffness ground and on different ground environments with variable stiffness.The active leg stiffness adjustment strategy combined with conventional attitude feedback control is tested,and results are compared with those using only a conventional attitude feedback control.Results show that through the active variable stiffness of the legs,the quadruped robot realizes the compensation and correction of the pitch and roll angle of the fuselage during the transition between soft and hard ground.Moreover,the control effect is better than

关 键 词：四足机器人 变刚度地面 软硬地面过渡 主动变刚度 姿态控制 

分 类 号：TP242.6[自动化与计算机技术—检测技术与自动化装置]