Study on Elastically Actuated Joints of Robot for Mimicking Musculo-tendinous Functions Based on SEAs

Abstract

Abstract:

In order to implement the capabilities of anthropomorphic locomotion and the compliances of contacting external environment in robot system, according to the SEA concept, this paper presented a type of elastically actuated robot revolution joint mimicking musculo-tendinous functions. It aimed at the compliant locomotion under the forced vibrations or the impacts. The joint mechanism refered to the Hill-type model of musculo-tendinous unit in human, untilizing the agonist-antangonist form of actively elastic drive and passively elastic constraint. The elastic actuation mainly imitateed the movements and functions of muscle contraction, which produced pulling force to drive the robot joint. Regarding the equations derived from dynamics analysis and the characteristic curves of joint movements in multiple simulations, the motion laws could be mastered, and the dynamics performances could be evaluated. In addition, for the joint characteristics of strong elasticity and low stiffness, the paper also proposed a virtual stiffness control method. This control approach was implemented in a 2 DOF articular robot arm applied with the elastically actuated joints, whose applicability and effectiveness were demonstrated by the experimental results.

Key words: bio-mechanism, robot, series elastic actuator(SEA), muscle-tendon, stiffness control

摘要：

为了实现机器人的拟人运动，提高其对外部环境的适应性，基于串联弹性驱动器(SEA)驱动形式提出一种仿肌弹性驱动的机器人转动关节，以实现机器人在受迫振动或受冲击下的柔顺自调整运动。该关节机构参考人体肌肉-肌腱组织的Hill-type模型，采用具有对抗形式的主动弹性驱动和被动弹性牵制的设计方案，模拟肌肉收缩运动和功能，产生牵拉力以驱动机器人的关节。通过对该弹性驱动关节进行建模分析，得到其动力学描述方程，结合多次仿真测试中获得的系统运动特性曲线，在掌握其运动规律的基础上完成了其动力学性能评估。此外，针对关节机构具有的强弹性、低刚度特点，提出一种基于虚拟刚度补偿的控制方法，并应用在具有仿肌弹性驱动关节的二自由度机器臂上，实验结果表明其可行、有效。

关键词: 仿生机构, 机器人, 串联弹性驱动器, 肌肉-肌腱, 刚度控制

CLC Number:

TP242

He Fuben, Liang Yande, Sun Jiefu, Guo Chao. Study on Elastically Actuated Joints of Robot for Mimicking Musculo-tendinous Functions Based on SEAs[J]. China Mechanical Engineering, 2014, 25(7): 900-905.

何福本, 梁延德, 孙捷夫, 郭超. 基于SEA的机器人仿肌弹性驱动关节研究[J]. 中国机械工程, 2014, 25(7): 900-905.

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