Semi-active vibration control of a flexible arm using joint stiffness control

Control of impact induced transient vibrations of a single-link flexible-arm using variable stiffness control (VSC) is revisited in this study. Previously, VSC was shown to be effective on a single-link flexible-arm whenthe active member of the controller consisted of an identical beam whose stiffness was derived from bending. The method was shown to be effective but the added mass of the active controller beam reduced the practicality of the prescribed method. A new active member that uses joint stiffness of a base actuator is proposed to overcome the limitation of its precursor. Case studies are conducted using numerical simulations to determine the effectiveness of the proposed method when arm parameters such as payload and base stiffness change on an existing arm. To verify the accuracy of the numerical predictions, an experimental rig is constructed. Results suggest that the proposed method is effective, versatile, and relatively insensitive to parameter variations.