Effective vibration suppression of a maneuvering two-link flexible arm with an event-based stiffness controller

Vibration control of a maneuvering flexible robotic arm is a challenging task in the presence of changing structural dynamics which has to deal with measurement inaccuracies and complex modeling efforts. This paper presents an effective and versatile controller for a maneuvering flexible arm. Proposed Variable Stiffness Control (VSC) is stable, due to its being dissipative in nature. The technique is suitable to be implemented as an add-on controller to existing robots, and it requires no additional hardware. Control is based on the detection of a kinematic event, peak relative displacement, rather than an accurate knowledge of structural dynamics. Hence, although there may not be a claim for the suggested control to be the most effective, it certainly represents significant practical advantages for cases where there may be structural uncertainties.