可调刚度致动器能为机器人动态性能和人机交互安全性带来显著提升。在对常见簧片型变结构式刚度调节机理进行分析总结的基础上设计一种基于折叠串联型平行排布簧片组的新型旋转式可调刚度致动器，分析其刚度调节原理并介绍样机机械结构。针对实际刚度调节机构中簧片与滑块滚子的间隙，建立修正的关节旋转刚度解析模型。通过系统试验证明了模型的准确性和整体方案的可行性。折叠式串联簧片的应用使系统在有限的尺寸和足够的承载能力下获得了更大的刚度调节范围。簧片的平行排布设计则实现了多组柔性单元滑块滚子运动的同步及关节驱动与刚度控制的解耦。
Variable stiffness actuators can significantly improve the dynamic performance of robots and ensure safety in human robot interaction. An overview of different principles working on most structure controlled variable stiffness mechanisms is presented. The design of a novel variable stiffness actuator and its working principle is described. Considering the gap between leaves and rollers in the real mechanism, the analytical joint stiffness model is modified to get a more accurate estimation of the prototype. Experiments are conducted to validate the model and the feasibility of the design. The application of folded serial leaf springs leads to an increased stiffness range while the size and load capacity remains unchanged. Motion synchronization of rollers and the decoupling of joint motion and stiffness adjustment are easily achieved by the parallel assembling of leaves.
[1] HOGAN N. Impedance control:An approach to manipulation[C]//American Control Conference, 1984, San Diego, CA, USA:IEEE, 1984:304-313.
[2] WILLIAMSON M M. Series elastic actuators[D]. Massachusetts:Massachusetts Institute of Technology, 1995.
[3] HURST J W, RIZZI A A. Series compliance for an efficient running gait[C]//IEEE Robotics & Automation Magazine, 2008:42-51.
[4] BIGGE B, HARVEY I R. Programmable springs:Developing actuators with programmable compliance for autonomous robots[J]. Robotics and Autonomous Systems, 2007, 55(9):728-734.
[5] TSAGARAKIS N G, LAFFRANCHI M, VANDERBORGHT B, et al. A compact soft actuator unit for small scale human friendly robots[C]//Robotics and Automation, 2009. ICRA'09. IEEE International Conference on, Kobe, Japan:IEEE, 2009:4356-4362.
[6] WOLF S, HIRZINGER G. A new variable stiffness design:Matching requirements of the next robot generation[C]//Robotics and Automation, 2008. ICRA 2008. IEEE International Conference on, Pasadena, CA:IEEE, 2008:1741-1746.
[7] BRAM V, TSAGARAKIS N G, Van HAM R, et al. MACCEPA 2.0:Compliant actuator used for energy efficient hopping robot Chobino1D[J]. Autonomous Robots, 2011, 31(1):55-65.
[8] WOLF S, EIBERGER O, HIRZINGER G. The DLR FSJ:Energy based design of a variable stiffness joint[C]//The DLR FSJ:Energy based design of a variable stiffness joint, Shanghai, China:IEEE, 2011:5082-5089.
[9] 隋春平,赵明扬. 3自由度并联柔索驱动变刚度操作臂的刚度控制[J]. 机械工程学报, 2006, 42(6):205-210. SUI Chunping, ZHAO Mingyang. Statics and stiffness study on a 3-dof parallel wire driven flexible manipulator[J]. Chinese Journal of Mechanical Engineering, 2006, 42(6):205-210.
[10] EIBERGER O, HADDADIN S, WEIS M, et al. On joint design with intrinsic variable compliance:Derivation of the DLR QA-joint[C]//2010 IEEE International Conference on Robotics and, Anchorage, Alaska, USA:IEEE, 2010:1687-1694.
[11] PETIT F, FRIEDL W, HOPPNER H, et al. Analysis and synthesis of the bidirectional antagonistic variable stiffness mechanism[J]. IEEE/ASME Transactions on Mechatronics, 2015, 20(2):684-695.
[12] TSAGARAKIS N G, IRENE S, CALDWELL D G. A new variable stiffness actuator (CompAct-VSA):Design and modelling[C]//2011 IEEE/RSJ International Conference on Intelligent Robots and Systems, San Francisco, CA:IEEE, 2011:378-383.
[13] KIM B S, SONG J B. Design and control of a variable stiffness actuator based on adjustable moment arm[J]. IEEE Transactions on Robotics, 2012, 28(5):1145-1151.
[14] JAFARI A, TSAGARAKIS N G, CALDWELL D G. A novel intrinsically energy efficient actuator with adjustable stiffness (AwAS)[J]. IEEE/ASME Transactions on Mechatronics, 2013, 18(1):355-365.
[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(3):322-329. YIN Peng, LI Mantian, GUO Wei, et al. Design and testing of a novel joint with adjustable stiffness for legged robot[J]. Robot, 2014, 36(3):322-329.
[16] CHOI J H, PARK S C, LEE W S, et al. A robot joint with variable stiffness using leaf springs[J]. IEEE Transactions on Robotics, 2011, 27(2):229-238.
[17] REN-JENG W, PANG H H. Mechanically stiffnessadjustable actuator using a leaf spring for safe physical human-robot interaction[J]. Mechanika, 2012, 18(1):77-83.
[18] SCHIMMELS J M, GARCES D R. The arched flexure VSA:A compact variable stiffness actuator with large stiffness range[C]//Robotics and Automation (ICRA), 2015 IEEE International Conference on, Seattle, WA:IEEE, 2015:220-225.
[19] TAO Y, WANG T, WANG Y, et al. Design and modeling of a new variable stiffness robot joint[C]//Multisensor Fusion and Information Integration for Intelligent Systems (MFI), 2014 International Conference on, Beijing:IEEE, 2014:1-5.
[20] 王伟,刘立冬,魏来,等. 柔性齿条式变刚度关节驱动器设计与研究[J]. 机械工程学报, 2016, 52(1):26-33. WANG Wei, LIU Lidong, WEI Lai, et al. Design and research of rack-based variable stiffness actuator[J]. Journal of Mechanical Engineering, 2016, 52(1):26-33.
[21] HOLLANDER K W, SUGAR T G, HERRING D E. Adjustable robotic tendon using a ‘Jack Spring’TM[C]//Rehabilitation Robotics, 2005. ICORR 2005. 9th International Conference on, IEEE, 2005:113-118.
[22] MORITA T, SUGANO S. Design and development of a new robot joint using a mechanical impedance adjuster[C]//Robotics and Automation, 1995 IEEE International Conference on, Nagoya:IEEE, 1995:2469-2475.
