POSITIVE VELOCITY FEEDBACK ON A SIX-LEGGED WALKING ROBOT

Six DoF are sufficient to define the position and orientation of a (robot) body in cartesian space. Insects have six legs containing three major joints each. This results in 18 joints that have to be coordinated which is a highly redundant task. During stance, usually several legs have ground contact at the same time and are coupled mechanically (closed kinematic chains). The control of such a system is generally assumed to require the explicit calculation of the body kinematics. In this paper we propose a biologically inspired solution that does not need such a body model. This is achieved by using implicit communication through the body mechanics (embodiment) and a local positive velocity feedback strategy (LPVF) on each single joint. In this decentral control scheme the locally measured joint velocity of an elastic joint is fed into the same joint during the next time step to maintain the movement. At the same time, an additional part of this joint controller observes the mechanical joint power to confine the positive feedback. The system is tested on a real physical robot.