.
 STIFF EU project on enhancing biomorphic agility through variable stiffness - DLR hands - logo by Ian Saunders - artificial arm and hand by TU Delft
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STIFF is a research project on enhancing biomorphic agility of robot arms and hands through variable stiffness & elasticity. It is funded by the 7th framework programme of the European Union (grant agreement No: 231576).


Check our 2011 Summer School on Impedance


Institutional Partners
German Aerospace Center (DLR), Germany:
Project coordinator. Responsible for integrating a variable-impedance robotic system in the project. Development of a novel EMG system for human impedance measurements. Integration of human and robotic impedance control approaches.

Technische Universiteit Delft, Netherlands:
Responsible for modelling the human neuromuscular system from muscle to joint level. Developent of time varying system identification and parameter estimation techniques to quantify the model parameters from recorded data using haptic manipulators.

IDSIA, Switzerland:
Responsible for learning high-level task-specific controllers based on reinforcement signals for the flexible variable-impedance robot arm developed by DLR, and for inverse reinforcement learning to extract cost functions in collaboration with UEDIN.

University of Edinburgh, United Kingdom:
Responsible for the development of 'Optimal Feedback Control' based closed loop control paradigms, specifically tailored to redundant and variable impedance actuators. Developing methods to extract cost functions and comparing control policies to evaluate improvement in performance when modulating impedance optimally.

Université Paris Descartes - CNRS, France:
Responsible for studies of impedance control in humans, using a variety of techniques including direct physiologicial measurements (EMG, H-reflex), mathematical modeling and robotic simulation. The main emphasis is 1) to suggest biologically-inspired strategies to be applied to robotics control and 2) to use analogies with robotic devices to better understand human behaviour in terms of impedance.

artificial DLR hand grabs a glass; humanoid robot javelin thrower cartoon by Juergen Schmidhuber

PUBLICATIONS

Below you will find all STIFF-related publications. Please note that all downloadable PDFs are for personal use only.
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  1. Braun, D.J. and Howard, M. and Vijayakumar, S. (2012). Optimal variable stiffness control: formulation and application to explosive movement tasks. Autonomous Robots, Special Issues on Robotics: Science and Systems 2011 33 (3), 237-253. under review [BibTex]

  2. Braun, D.J. and Howard, M. and Vijayakumar, S. (2011). Exploiting variable stiffness in explosive movement tasks. [BibTex]

  3. Castellini C, Smagt P van der (2009). Surface EMG in Advanced Hand Prosthetics. Biological Cybernetics 100 (1), 35-47. [pdf] [BibTex]

  4. D. J. Braun and F. Petit and F. Huber and S. Haddadin and P. van der Smagt and A. Albu-Schaeffer and S. Vijayakumar (2012). Optimal Torque and Stiffness Control in Compliantly Actuated Robots. Proc. IEEE-RSJ IROS [BibTex]

  5. Eesbeek S van, Vlugt E de, Verhaegen M (2011). Time Variant Subspace Identification of Joint Impedance. Proceedings of the XXIIIth Congress of the ISB [BibTex]

  6. Glasmachers T, Schaul T, Schmidhuber J (2010). Evolution Strategy for Multi-Objective Optimization. Parallel Problem Solving from Nature (PPSN) XI [pdf] [BibTex]

  7. Glasmachers T, Schaul T, Sun Y, Wierstra D, Schmidhuber J (2010). Exponential Natural Evolution Strategies. Genetic and Evolutionary Computation Conference (GECCO) [pdf] [BibTex]

  8. Glasmachers, T. and Koutn{\i}k, J. and Schmidhuber, J. Kernel Representations for Evolving Continuous Functions. Evolutionary Intelligence [BibTex]

  9. Grebenstein M, Albu-Schäffer A, Bahls T, Chalon M, Eiberger O, Friedl W, Gruber R, Hagn U, Haslinger R, Höppner H, Jörg S, Nickl M, Nothelfer A, Petit F, Reill J, Seitz N, Wimböck T, Wolf S, Wüsthoff T, Hirzinger G (2011). The DLR Hand Arm System. ICRA [BibTex]

  10. Gustus A, Smagt P van der (2011). Energy Storage and Release in Human extensor digitorum communis Muscle. Applied Bionics and Biomechanics accepted [BibTex]

  11. Höppner H, Lakatos D, Urbanek H, Castellini C, van der Smagt P (2011). The Grasp Perturbator: Calibrating human grasp stiffness during a graded force task. Proceedings of the International Conference on Robotics and Automation accepted [pdf] [BibTex]

  12. Höppner H, Lakatos D, Urbanek H, Smagt P van der (2010). The Arm-Perturbator: Design of a Wearable Perturbation Device to measure Limb Impedance. International Conference on Applied Bionics and Biomechanics (ICABB) [pdf] [BibTex]

  13. Howard M, Braun D, Vijayakumar S (2011). Constraint-based Equilibrium and Stiffness Control of Variable Stiffness Actuators. IEEE International Conference on Robotics and Automation [www] [BibTex]

  14. Howard M, Klanke S, Gienger M, Goerick C, Vijayakumar S (2009). A Novel Method for Learning Policies from Constrained Motion. Proc. IEEE International Conference on Robotics and Automation (ICRA '09) 1717-1722. [pdf] [BibTex]

  15. Howard M, Klanke S, Gienger M, Goerick C, Vijayakumar S (2010). Methods for Learning Control Policies from Variable-constraint Demonstrations. In Olivier Sigaud and Jan Peters (Eds.) From Motor Learning to Interaction Learning in Robots Springer Berlin / Heidelberg: 253-291. [pdf] [doi] [BibTex]

  16. Howard M, Mitrovic D, Vijayakumar S (2010). Transferring Impedance Control Strategies Between Heterogeneous Systems via Apprenticeship Learning. IEEE-RAS International Conference on Humanoid Robots [www] [BibTex]

  17. Howard, M. and Braun, D.J. and Vijayakumar, S. (2011). Transferring Human Impedance Behaviour to Heterogeneous Variable Impedance Actuators. IEEE Transactons on Robotics [BibTex]

  18. Howard, M. and Braun, D.J. and Vijayakumar, S. (2011). Constraint-based equilibrium and stiffness control of variable stiffness actuators. Robotics and Automation (ICRA), 2011 IEEE International Conference on 5554--5560. [BibTex]

  19. H\"oppner, H. and Lakatos, D. and Urbanek, H. and Castellini, C. and van der Smagt, P. (2011). The Grasp Perturbator: Calibrating human grasp stiffness during a graded force task. Robotics and Automation (ICRA), 2011 IEEE International Conference on 3312--3316. [BibTex]

  20. Koutnik J, Gomez F, Schmidhuber J (2010). Searching for Minimal Neural Networks in Fourier Space. Proceedings of The Third Conference on Artificial General Intelligence (AGI 2010) [pdf] [BibTex]

  21. Lakatos, D (2011). Identifikation der Impedanzparameter des menschlichen Arms mit dem sieben-Achs DLR Leichtbauroboter. [BibTex]

  22. Lakatos, D. and Petit, F. and Smagt, P. (2011). Conditioning vs. excitation time for estimating impedance parameters of the human arm. Humanoid Robots (Humanoids), 2011 11th IEEE-RAS International Conference on 636--642. [BibTex]

  23. Mitrovic D, Klanke S, Howard M, Vijayakumar S (2010). Exploiting Sensorimotor Stochasticity for Learning Control of Variable Impedance Actuators. IEEE-RAS International Conference on Humanoid Robots [www] [BibTex]

  24. Mitrovic D, Klanke S, Osu R, Kawato M, Vijayakumar S (2010). A Computational Model of Limb Impedance Control based on Principles of Internal Model Uncertainty. PLoS ONE 5 (10), [www] [BibTex]

  25. Mitrovic D, Klanke S, Vijayakumar S (2010). Adaptive Optimal Feedback Control with Learned Internal Dynamics Models. In Olivier Sigaud and Jan Peters (Eds.) From Motor Learning to Interaction Learning in Robots Springer Berlin / Heidelberg: 65-84. [pdf] [doi] [BibTex]

  26. Mitrovic D, Nagashima S, Klanke S, Matsubara T, Vijayakumar S (2010). Optimal Feedback Control for Anthropomorphic Manipulator. Proc. IEEE International Conference on Robotics and Automation [BibTex]

  27. Mitrovic D, Rawlik K, Klanke S, Vijayakumar S (2009). A Theory of Impedance Control based on Internal Model Uncertainty. Proc. European Science Foundation (ESF) Intl. Workshop on Computational Principles of Sensorimotor Learning [BibTex]

  28. Mitrovic, D. and Klanke, S. and Vijayakumar, S. (2011). Learning impedance control of antagonistic systems based on stochastic optimization principles. The International Journal of Robotics Research 30 (5), 556. [BibTex]

  29. Mori, T. and Howard, M. and Vijayakumar, S. Model-Free Apprenticeship Learning for Transfer of Human Impedance Behaviour. 11th IEEE-RAS International Conference on Humanoid Robots [BibTex]

  30. Nakanishi, J and Rawlik, K and Vijayakumar, S. Stiffness and Temporal Optimization in Periodic Movements: An Optimal Control Approach. IEEE/RSJ Intl. Conf. on Intelligent Robots and Systems [BibTex]

  31. Onneweer B (2010). Recovery of reflexes at the elbow after surgery on severe brachial plexus injuries.. [BibTex]

  32. Onneweer B, Vlugt E de, Helm F van der Spatial changes in arm stiffness between multi-joint position and force tasks. [BibTex]

  33. Rawlik K, Toussaint M, Vijayakumar S (2010). An Approximate Inference Approach to Temporal Optimization in Optimal Control. Proc. Advances in Neural Information Processing Systems [www] [BibTex]

  34. Smagt P van der, Grebenstein M, Urbanek H, Fligge N, Strohmayr M, Stillfried G, Parrish J, Gustus A (2009). Robotics of human movements. Journal of Physiology - Paris 103 (3-5), 119-132. [doi] [BibTex]

  35. Smagt P van der, Helm F van der, Schmidhuber J, Vijayakumar S, McIntyre J (2010). Enhancing biomorphic agility through variable stiffness. Proc. 4th International Conference on Cognitive Systems Zürich [BibTex]

  36. Snijders JW Visser JMA Korstanje WH Selles RW Veeger HEJ (2011). Determination of Moment Arms of the MCP Joint In-Vivo Using Ultrasound. Proceedings of the XXIIIth Congress of the ISB [BibTex]

  37. Stillfried G, Smagt P van der (2010). Movement model of a human hand based on magnetic resonance imaging (MRI). International Conference on Applied Bionics and Biomechanics (ICABB) [pdf] [BibTex]

  38. Sun Y, Gomez F, Schmidhuber J (2010). Improving Asymptotic Performance of Markov Chain Monte-Carlo by Inserting Vortices. Neural Information Processing Systems (NIPS) [pdf] [BibTex]

  39. Tagliabue M, De Vlught E, van der Helm F, McIntyre J (2010). Anisotropic changes in task precision constraints do not lead to an anisotropic modulation of the hand trajectory control. Neuroscience Meeting Planner [pdf] [BibTex]

  40. Van der Greft, I and De Groot, JH and Van Eesbeek, S and Meskers, CGM and De Vlugt, E Short range stiffness and elastic limit are equal for eccentric and concentric loading. [BibTex]

  41. Vardy W, Soest K van, Vlugt E de, Helm F van der A State Space Muscle-Tendon Model using the Huxley Cross-Bridge Model. [BibTex]

  42. Vardy, AN and de Vlugt, E and van der Helm, FCT. (2011). In vivo parameter estimation for the Huxley cross-bridge model.. Proceedings of the XXIIIth Congress of the ISB [BibTex]

  43. Vardy, AN and Lemaire, KK and van Soest, AJ and de Vlugt, E and van der Helm, FCT. A state space muscle-tendon model using the Huxley cross-bridge model.. [BibTex]

  44. Vijayakumar S, Toussaint M, Petkos G Howard M (2009). Planning and Moving in Dynamic Environments: A statistical machine learning approach. In Sendhoff, Koerner, Sporns, Ritter, Doya (Eds.) Creating Brain-Like Intelligence Springer-Verlag: 151-191. [doi] [www] [BibTex]

  45. Visser, JMA and van der Helm, FCT and Veeger, HEJ A finite element musculoskeletal model of the hand and wrist. [BibTex]

  46. Vlugt E de, Eesbeek S van, Baines P, Hilte J, Meskers C, Groot J de (2011). Short Range Stiffness Elastic Limit depends on Joint Velocity. Journal of Biomechanics in review [BibTex]

  47. Vlugt E de, Eesbeek S van, Helm F van der (2011). Continuous Estimation of Arm Impedance during Movement. Journal of Multibody System Dynamics (Special Issue) in review [BibTex]

  48. Vogel, J. and Castellini, C. and van der Smagt, P. (2011). EMG-based teleoperation and manipulation with the DLR LWR-III. Intelligent Robots and Systems (IROS), 2011 IEEE/RSJ International Conference on 672--678. [BibTex]

  49. Yi S, Wierstra D, Schaul T, Schmidhuber J (2009). Efficient Natural Evolution Strategies. Genetic and Evolutionary Computation Conference (GECCO-09) Best Paper Award [pdf] [doi] [BibTex]

 artificial DLR arm and hand; artificial hand squeezes STIFF
artificial DLR hand holding a wine bottle