neoDavid - A humanoid robot with variable stiffness actuation and dexterous manipulation skills

The wheeled humanoid neoDavid is with its 52 Degrees of freedom, 95 brushless dc motors, 184 position and 3 force sensors, and a control frequency of 3 kHz one of the most complex humanoid robots worldwide. All finger joints can be controlled individually, giving the system exceptional dexterity. neoDavids Variable Stiffness Actuators (VSAs) enable very high performance in the tasks with fast collisions, highly energetic vibrations, or explosive motions, such as hammering, using power-tools, e.g. a drill-hammer, or throwing a ball. The Elastic Structure Preserving (ESP) control concept was developed for compliant VSA robots. To the best of our knowledge, ESP is the world’s first, experimentally validated, (globally asymptotically stable and passive) motion tracking controller with link-side damping injection for VSA robots. Demanding manipulation tasks require grasp state knowledge. Our method to estimate the grasp state integrates information from proprioception and vision. Utilizing the estimated grasp state, the developed model-based controller realizes the compliant positioning of the object inside the hand. neoDavid’s dexterous manipulation skills are further enabled through our M3T tracking framework, which incorporates visual feedback with forward kinematics and joint measurements. This allows us to simultaneously track the right arm as well as desired objects at real time and cope with severe object occlusions. We present the first prototypes of VSAs and multiple generations of hands and body components. Keeping our long-term vision of a dexterous and robust service robot in mind, our focus changed from technological basics to skills and finally applications.