Compliance and Oscillations in Robotics - on Bad and Good Vibrations

Kurzfassung

In the early days of robotics, hardware compliance used to be regarded as a drawback, reducing the positioning and tracking precision of robots and causing undesired vibration, hard to address by control. Meanwhile, a certain level of compliance, even a mechanically adjustable one, is widely regarded as indispensable for interaction with humans and for skillful manipulation in contact with stiff environments. Also in legged locomotion, inspired by the biological archetypes, many roboticists exploit elasticity for robustness and energy efficiency. At latest here, the complex oscillations of multi-body, compliant systems are not any more parasitic and unwanted, but become an essential feature for achieving performance. However, for treating these highly nonlinear oscillations, new mathematical tools are required, which are currently a topic of intensive research. The talk will give an overview on the evolution of the robotics perspective on compliance and nonlinear oscillations both from hardware design and from control point of view. It will therefore present several examples of DLR robots for manipulation and locomotion in various application areas.