Control



Arm

Active Damping Control

The low intrinsic damping properties of variable stiffness mechanisms lead to oscillatory dynamical behavior (cf. right picture). A desired convergence behavior can be achieved by active damping control based on state feedback control and the system flatness property (cf. left picture).

Active / Passive Cartesian Impedance Control

The combination of active (impedance) control with passive elasticities increases the stiffness range and shape.

Impedance_en_200x200

Optimal Control / Cyclic Motion Control

The elastic energy storage of the variable stiffness actuators can be exploited to generate explosive and cyclic motions. Thereby, the natural dynamics of the plant is excited.

Cyclic Motion

Hand

  • anthropomorphic kinematic offers excellent grasping capabilities
  • flexible tendons provide impressive robustness but require complex control scheme

Frequency Analysis

  • internal forces can modulate the joint stiffness but must satisfy the torque and pulling constraints

 

Selected Publications

[1] Lakatos, Dominic and Petit, Florian and Albu-Schäffer, Alin (2014) Nonlinear Oscillations for Cyclic Movements in Human and Robotic Arms, Robotics, IEEE Transactions on , vol.30, no.4, pp.865,879, Aug. 2014, doi: 10.1109/TRO.2014.2308371

[2] Reinecke, Jens and Chalon, Maxime and Friedl, Werner and Markus, Grebenstein (2014) Guiding Effects and Friction Modeling for Tendon Driven Systems. In: IEEE International Conference on Robotics and Automation (ICRA). ICRA 2014, May 31 to June 5, Hong Kong

[3] Chalon, Maxime; D'Andrea-Novel, Brigitte (2014) Backstepping Experimentally Applied to an Antagonistically Driven Finger with Flexible Tendons, IFAC World Congress 2014, vol.19, no.1

[4] Wimböck, Thomas and Reinecke, Jens and Chalon, Maxime (2012) Derivation and Verification of Synergy Coordinates for the DLR Hand Arm System. In: Proceedings of CASE 2012. 8th IEEE International Conference on Automation Science and Engineering, August 20-24, 2012, Seoul, Korea.

[5] Petit, Florian and Albu-Schäffer, Alin (2011) Cartesian impedance control for a variable stiffness robot arm, Intelligent Robots and Systems (IROS), 2011 IEEE/RSJ International Conference on , vol., no., pp.4180,4186, 25-30 Sept. 2011, doi: 10.1109/IROS.2011.6094736

[6] Petit, Florian and Albu-Schäffer, Alin (2011) State feedback damping control for a multi DOF variable stiffness robot arm, Robotics and Automation (ICRA), 2011 IEEE International Conference on , vol., no., pp.5561,5567, 9-13 May 2011, doi: 10.1109/ICRA.2011.5980207

[7] Chalon, Maxime and Wimboeck, Thomas and Hirzinger, Gerd (2010) Torque and workspace analysis for flexible tendon driven mechanisms. IEEE International Conference on Robotics and Automation (ICRA), 2010, 3-7 May 2010, Anchorage, AK. ISBN 978-1-4244-5038-1. ISSN 1050-4729


Contact
Sebastian Wolf
German Aerospace Center

Institute of Robotics and Mechatronics
, Mechatronic Components and Systems
Tel: +49 8153 28-1060

Fax: +49 8153 28-1134

E-Mail: sebastian.wolf@dlr.de
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