Simultaneous rigid-body motion and vibration control of a flexible four-bar linkage

A model and a control scheme for a flexible four-bar linkage is described. The discrete finite element model of the mechanism accounts for geometric and inertial nonlinearities. A reduced number of measured variables are selected to control both rigid-body motion and vibration separately. Rigid-body motion control is performed by means of a PID-like regulator while proportional controllers are employed to damp link oscillations. Appropriate devices are proposed to avoid coupling effects among variables. Numerical results demonstrate the effectiveness of the control scheme.