Robust vibration control of flexible cable-strut structure with mixed uncertainties

The design method of μ-synthesis controller for the flexible cable-strut structure with mixed uncertainties was presented and verified by the simulation experiments. The uncertainties include model uncertainties caused by joint clearance and friction, and the uncertainties arising from the actuator range and sensor noise. Based on the structured singular value theory, the model of robust active vibration control for the flexible cable-strut structure was established. The robust performance of the external disturbance rejection is characterized by introducing a fictitious uncertainty block across the disturbance/error channels and carrying out a robust stability analysis. The controller was derived from minimizing the structured singular value. This method considers the structural characteristics of the mixed uncertainty block, so that the conservativeness of H∞ controller in dealing with the mixed uncertainty problem is avoided. The simulation results show that the method has good robustness and stability performances for the controlled system with mixed uncertainties and external disturbances.