Dynamic modelling and control of variable stiffness actuators

After briefly summarizing the mechanical design of the two joint prototypes for the new DLR variable compliance arm, the paper exemplifies the dynamic modelling of one of the prototypes and proposes a generic variable stiffness joint model for nonlinear control design. Based on this model, the design of a simple, gain scheduled state feedback controller for active vibration damping of the mechanically very weakly damped joint is presented. Moreover, the computation of the motor reference values out of the desired stiffness and position is addressed. Finally, simulation and experimental results validate the proposed methods.

[1]  Alin Albu-Schäffer,et al.  The DLR lightweight robot: design and control concepts for robots in human environments , 2007, Ind. Robot.

[2]  Shigeki Sugano,et al.  Development and evaluation of seven DOF MIA ARM , 1997, Proceedings of International Conference on Robotics and Automation.

[3]  Alessandro De Luca,et al.  Nonlinear decoupled motion-stiffness control and collision detection/reaction for the VSA-II variable stiffness device , 2009, 2009 IEEE/RSJ International Conference on Intelligent Robots and Systems.

[4]  Alin Albu-Schäffer,et al.  A passivity based Cartesian impedance controller for flexible joint robots - part II: full state feedback, impedance design and experiments , 2004, IEEE International Conference on Robotics and Automation, 2004. Proceedings. ICRA '04. 2004.

[5]  Shigeki Sugano,et al.  Development of human symbiotic robot: WENDY , 1999, Proceedings 1999 IEEE International Conference on Robotics and Automation (Cat. No.99CH36288C).

[6]  Zhiwei Luo,et al.  Bio-mimetic study on pinching motions of a dual-finger model with synergistic actuation of antagonist muscles , 2006, Proceedings 2006 IEEE International Conference on Robotics and Automation, 2006. ICRA 2006..

[7]  Hiroaki Kobayashi,et al.  Adaptive neural network control of tendon-driven mechanisms with elastic tendons , 2003, Autom..

[8]  Alin Albu-Schäffer,et al.  On the Passivity-Based Impedance Control of Flexible Joint Robots , 2008, IEEE Transactions on Robotics.

[9]  Bram Vanderborght,et al.  Exploiting Natural Dynamics to Reduce Energy Consumption by Controlling the Compliance of Soft Actuators , 2006, Int. J. Robotics Res..

[10]  Gerd Hirzinger,et al.  Feedback linearization and simultaneous stiffness-position control of robots with antagonistic actuated joints , 2007, Proceedings 2007 IEEE International Conference on Robotics and Automation.

[11]  Alin Albu-Schäffer,et al.  Soft robotics: what Cartesian stiffness can obtain with passively compliant, uncoupled joints? , 2004, 2004 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS) (IEEE Cat. No.04CH37566).

[12]  Stephen P. DeWeerth,et al.  Biologically Inspired Joint Stiffness Control , 2005, Proceedings of the 2005 IEEE International Conference on Robotics and Automation.

[13]  Alin Albu-Schäffer,et al.  Constructive Energy Shaping Based Impedance Control for a Class of Underactuated Euler-Lagrange Systems , 2005, Proceedings of the 2005 IEEE International Conference on Robotics and Automation.

[14]  G. Hirzinger,et al.  A new variable stiffness design: Matching requirements of the next robot generation , 2008, 2008 IEEE International Conference on Robotics and Automation.

[15]  Antonio Bicchi,et al.  Fast and "soft-arm" tactics [robot arm design] , 2004, IEEE Robotics & Automation Magazine.

[16]  Koichi Koganezawa,et al.  Mechanical stiffness control for antagonistically driven joints , 2005, 2005 IEEE/RSJ International Conference on Intelligent Robots and Systems.

[17]  Alin Albu-Schäffer,et al.  Bidirectional antagonistic variable stiffness actuation: Analysis, design & Implementation , 2010, 2010 IEEE International Conference on Robotics and Automation.

[18]  Alin Albu-Schäffer,et al.  On joint design with intrinsic variable compliance: derivation of the DLR QA-Joint , 2010, 2010 IEEE International Conference on Robotics and Automation.

[19]  Donald Russell,et al.  Implementation of variable joint stiffness through antagonistic actuation using rolamite springs , 1999 .