Abstract

In recent years, there has been a growing attention towards the design of actuators and transmission mechanisms that can make robots of the next generation to perform powerful, accurate and fast motion, while remaining at all times safe for humans in their vicinity or nearby. Actuators with adaptable passive impedance are also useful for tuning the mechanism to the interaction with the human or the environment - as e.g. in prosthetics or autonomous locomotion. A strong argument in favour of intrinsic joint compliance is its property to serve as an energy storage mechanism, possibly decreasing the energy consumption of the entire system during task execution. Furthermore, the stored energy can be used to considerably increase the peak link speed or force in order to approach human performance. Finally, many researchers are interested in the variable stiffness (and in particular the antagonistic) design approach from a bio-robotics point of view, with the aim of better understanding the principles of human motion and its control.

Naturally, such a fundamental design paradigm shift comes at a certain cost. The increased number of actuators and the small intrinsic damping of most implementations are certainly some of the major challenges in controlling a variable compliance joint. The expected reduction in absolute position accuracy due to the elasticity needs to be compensated by external sensing as e.g. vision. Furthermore, a lower mechanical bandwidth will be the consequence due to the generally higher joint compliance. The various existing viewpoints on the topic as well as the mentioned open problems motivate the workshop as a platform for experience exchange and discussions. In this workshop, we plan to bring together top researchers in the fundamentals of electromechanical design, planning, and control of new actuators, pHRI safety, and biorobotics. We intend to make a point on the state of the art, initiate discussions about open problems and perspectives of variable impedance design, enable interdisciplinary and inter-group cooperation, and to further spread knowledge about the methods, the technologies, and the challenges in this field.