Vibration Damping of Flexible Link Robots using an Eye-in-Hand Camera

Due to their low weight robots with flexible links are ideal candidates for use in dynamically demanding applications. Since the main goal of the robot control is to achieve precise positioning, the damping of oscillations due to low stiffness is imperative. Furthermore classical PD motor position control is insufficient for vibration damping. This paper presents an approach using an eye-in-hand camera for vibration damping of an elastic articulated robot with three actuated joints. The idea is to use the position of feature points in the camera image for generating a feedback signal. The image feature position is transformed into the joint space using the image Jacobian. The PD motor control is augmented by a proportional term w.r.t. a virtual arm angle. Experimental results of a comparison with a control concept based on acceleration sensors are presented.