Session 2: Variable impedance actuators and parallel compliance and their relation to biology

Heike Vallery, TU Delft

Bio: Heike Vallery received her Dipl.-Ing. degree in Mechanical Engineering (with honors) from RWTH Aachen University in 2004 and her Dr.-Ing. in robotics from the Technische Universität München in 2009, where she had worked on compliant actuation and cooperative control principles for gait rehabilitation robots. As a postdoctoral fellow at the SMS Lab at ETH Zürich, she continued this research and developed several mechatronic principles for cooperative human-robot interaction. Based on these principles, she conceived a robot for overground gait training in rats, which enabled ground-breaking research on recovery after spinal cord injury at EPFL in Switzerland. She also established a research group on leg exoprosthetics. From 2011 to 2012, she worked at Khalifa University in Abu Dhabi as an assistant professor. Today, she is full professor at TU Delft. Heike Vallery has published more than 60 peer-reviewed publications, filed 7 patent applications, and received diverse fellowships and awards, such as the 1st prize of the euRobotics Technology Transfer Award 2014 for the project “THE FLOAT”, a Vidi fellowship in 2016 from the Netherlands Organisation for Scientific Research, and the Henk-Stassen Award for Best Young Researcher BME 2017.

Title: Minimalistic design for compliant multi-DOF actuation

Abstract: Human gait requires complex coordination of many degrees of freedom (DOF). Assisting such motion with conventional single-DOF robotic actuators can lead to bulky and complex designs. This talk presents underactuated and fully actuated design solutions for minimalistic compliant actuation of such multi-DOF applications. Several implementation examples will be shown, including two recent developments: A treadmill-based 6-DOF pelvis support module to assist lateral weight shifting during gait training, and the low-power body weight support system RYSEN that can render forces in three directions during overground gait.

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Steve Collins, Stanford University

Bio: Steve Collins received his B.S. in Mechanical Engineering in 2002 from Cornell University, where he performed research on passive dynamic walking robots with Andy Ruina. He received his Ph.D. in Mechanical Engineering in 2008 from the University of Michigan, where he performed research on the dynamics and control of human walking with Art Kuo. He performed postdoctoral research on humanoid robots with Martijn Wisse at T. U. Delft in the Netherlands. He was a professor of Mechanical Engineering and Robotics at Carnegie Mellon University for seven years. In 2017, he joined the faculty of Mechanical Engineering at Stanford University, where he teaches courses on design and robotics and directs the Stanford Biomechatronics Lab. His primary focus is to speed and systematize the design and prescription of prostheses and exoskeletons using versatile device emulator hardware and human-in-the-loop optimization algorithms (Zhang et al. 2017, Science). Another focus is efficient autonomous devices, such as highly energy-efficient walking robots (Collins et al. 2005, Science) and exoskeletons that use no energy yet reduce the metabolic energy cost of human walking (Collins et al. 2015, Nature). He is a member of the Scientific Board of Dynamic Walking and an Associate Editor of the International Journal of Robotics Research. He has received the Young Scientist Award from the American Society of Biomechanics, the Best Medical Devices Paper from the International Conference on Robotics and Automation, and the student-voted Professor of the Year in his department. More information at

Title: Lightweight, low-power electroadhesive clutches for biorobotic actuation

Abstract: The performance of exoskeletons, active prostheses and legged robots is limited by the high weight and power consumption of conventional actuators and transmissions. Clutches could be used to help address these issues, but have traditionally been too heavy and inefficient to provide a net benefit. We have developed a new type of clutch, based on electrostatic adhesion, that achieves order of magnitude improvements in mass and energy consumption. An example clutch can hold 190 N of force, weighs 15 grams, consumes 3 mW of power, and engages or disengages in 20 ms. This enables exciting new approaches to robotic actuation, including designs that incorporate tens or hundreds of independently controlled clutches, with parallels to the architecture of skeletal muscle. In this talk, we will explain how the clutch is fabricated and describe empirically-derived design principles for a variety of applications. We will also discuss implementation in an ankle exoskeleton and the ongoing design of an energy-recycling actuator employing many clutched springs.

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Sami Haddadin, Technische Universität München

Bio: Sami Haddadin (M’11) received the Dipl.-Ing. degree in electrical engineering in 2005, the M.Sc. degree in computer science in 2009 from Technical University of Munich (TUM), Munich, Germany, the Honours degree in technology management in 2007 from Ludwig Maximilian University, Munich, Germany, and TUM, and the Ph.D. degree in safety in robotics from RWTH Aachen University, Aachen, Germany, in 2011. Then, he became a Full Professor and the Director of the Institute of Automatic Control, Leibniz University Hannover, Hanover, Germany. Recently he moved to TU München. He organized/edited several international robotics conferences and journals and published more than 140 scientific articles. His research interests include physical human–robot interaction, nonlinear robot control, real-time motion planning, real-time task and reflex planning, robot learning, optimal control, human motor control, variable impedance actuation, and safety in robotics.

Title: Elastic actuation in robotics and control

Abstract: To be announced.

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