Design and Analysis of a Active-passive Variable Stiffness Flexible Joint

doi:10.3901/JME.2018.03.055

Abstract

Abstract: In order to solve the limitation of traditional rigid robot application in specific fields, a composite flexible joint with active and passive variable stiffness characteristics is designed. By studying the structure of variable stiffness flexible joints at home and abroad, the variable stiffness flexible joint is divided into two kinds of lever mechanism and cam mechanism according to the structure principle. And based on the principle of cam mechanism, the integration of Active-Passive variable stiffness in the same joint is realized by the compact design. The curve of cam groove is optimized through establishing mathematical model, and the property that the equivalent stiffness of joints increases gradually with the flexible deformation is finally realized. On this basis, the stiffness characteristics of flexible joints are analyzed. The static and dynamic stiffness measurement experiments of the joint prototype were carried out and the experimental results show that the variable stiffness flexible joint can realize the active and passive stiffness adjustment function and adapt to the existing robot mechanism in structural design.

Key words: flexible joint, robot joint, variable stiffness

CLC Number:

TP242

SHI Yanlei, ZHANG Xiaojun, ZHANG Minglu. Design and Analysis of a Active-passive Variable Stiffness Flexible Joint[J]. Journal of Mechanical Engineering, 2018, 54(3): 55-62.

References

[1] BURGARD W,BROCK O,STACHNISS C. Safety evaluation of physical human-robot interaction via crash-testing[C]// Proceedings of Robotics:Science & Systems Iii,June,2007,Georgia Institute of Technology,2007,Atlanta,Georgia,Usa:MIT Press,2007:217-224.
[2] MARKUS G,PATRICK V D S. Antagonism for a highly anthropomorphic hand-arm system[J]. Advanced Robotics,2008,22(1):39-55.
[3] KOGANEZAWA K,Mechanical stiffness control for antagonistically driven joints[C]// Proceedings of the IEEE/RSJ International Conference on Intelligent Robots and Systems,2005,Edmonton,Alberta,Canada. IEEE/RSJ,2005:2512-2519.
[4] BICCHI A,TONIETTI G. Fast and soft-arm tactics-dealing with the safety-performance tradeoff in robot arms design and control[J]. IEEE Robotics & Automation Magazine,2004,6:22-33.
[5] 王巍,贺平,万良辉. 飞机柔性装配技术研究[J]. 机械设计与制造,2006(11):88-90. WANG Wei,HE Ping,WAN Lianghui. Study of technology on aeroplane flexible assembly[J]. Machinery Design & Manufacture,2006 (11):88-90.
[6] ALEXANDER R M. The maximum forces exerted by animals[J]. Journal of Experimental Biology,1985,115:231-238.
[7] ROBERTS T J,MARSH R L,WEYAND P G,et al. Muscular force in running turkeys:The economy of minimizing work[J]. Science,1997,275(5303):1113-1115.
[8] COLLINS S,RUINA A,TEDRAKE R,et al. Efficient bipedal robots based on passive-dynamic walkers[J]. Science,2005,307(5712):1082-1085.
[9] 毛勇,王家廞,贾培发,等. 双足被动步行研究综述[J]. 机器人,2007,29(3):274-280. MAO Yong,WANG Jiaxin,JIA Peifa,et al. Passive dynamic biped walking a survey[J]. Robot,2007,29(3):274-280.
[10] ANDERSON S,WISSE M,ATKESON C G,et al. Powered bipeds based on passive dynamic principles[C]// Proceedings of the 5th IEEE-RAS International Conference on Humanoid robots,2005,Tsukuba,Japan. IEEE,2005:110-116.
[11] DALLEAU G,BELLI A,BOURDIN M,et al. The spring-mass model and the energy cost of treadmill running[J]. European Journal of Applied Physiology,1998,77(3):257-63.
[12] WOLF S,HIRZINGER G. A new variable stiffness design:Matching requirements of the next robot generation[C]// Proceedings of IEEE International Conference on Robotics and Automation(ICRA),2008,Pasadena,California,USA. IEEE,2008:1741-1746.
[13] WOLF S,EIBERGER O,HIRZINGER G. The DLR FSJ:Energy based design of a variable stiffness joint[C]// Proceedings of IEEE International Conference on Robotics and Automation(ICRA),2011,Shanghai,China. IEEE,2011:5082-5089.
[14] JAFARI A,TSAGARAKIS N G,VANDERBORGHT B,et al. A novel actuator with adjustable stiffness (AwAS)[C]// Proceedings of IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS),2010, Taipei,Taiwan,China. IEEE,2010:4201-4206.
[15] 尹鹏,李满天,郭伟,等. 面向足式机器人的新型可调刚度柔性关节的设计及性能测试[J]. 机器人,2014,36(6):676-682 YIN Peng,LI Mantian,GUO Wei,et al.Design and testing of a novel joint with adjustable stiffness for legged robot[J]. Robot,2014, 3:322-329..
[16] 范秦海,周越. 肌肉弹性力量对运动员跳跃能力的影响[C]// 全国运动生物力学学术交流大会,2002,石家庄,2002:154-156. FAN Qinhai,ZHOU Yue. Effects of muscle elastic strength on jumping ability of athletes[C]// Proceedings of National Conference on Sports Biomechanics,2002,Shijiazhuang. 2002:154-156.
[17] 魏勇,刘宇. 运动中下肢刚度变化及其机制研究进展[J]. 中国运动医学杂志,2009,28(2):222-225. WEI Yong,LIU Yu. Research progress on changes and mechanism of lower limb stiffness in exercise[J]. Chinese Journal of Sports Medicine,2009,28(2):222-225.
[18] 马洪文,赵朋,王立权,等. 刚度和等效质量对SEA能量放大特性的影响[J]. 机器人,2012,34(3):275-281. MA Hongwen,ZHAO Peng,WANG Liquan,et al.Series elastic actuator mechanical model and stability analysis[J]. Journal of Harbin Engineering University,2012,34(3):275-281.
[19] KUBO K,KAWAKAMI Y,FUKUNAGA T. Influence of elastic properties of tendon structures on jump performance in humans[J]. Journal of Applied Physiology,1999,87:2090-2096.