The objective of this paper is to describe and numerically test a control scheme for a flexible four-bar linkage. The dynamic response of the mechanism is reproduced by means of an accurate finite element model accounting for geometric and inertial nonlinearities. A reduced number of measured variables is selected to control both rigid-body motion and vibration separately without implementing an estimator of the state of the system. 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 when it operates at different sampling times.
