Numerical and experimental investigations into feedback control of continuous beam structures under moving loads

This paper presents and validates a novel approach to designing an active controller for a small-scale experimental structure subjected to the action of multiple moving loads. Many of the numerically validated active control methods presented in the literature assume that the synthesised control solution can be applied directly to the structure. When a real structure is investigated, the closed-loop stability and performance of the system are affected by the actuators’ dynamics and by the signal-to-noise ratio. In some cases when the structure is complex, the model used for the structure can have controllability and observability problems. In this study, an active control solution is designed using a simplified model, and then, it is experimentally validated. The control voltage dependent on the measured displacement signals is fed back to the structure via electrodynamic actuators. The objective of the control is to reduce the structure’s deflection under the action of the loads at sensors’ locations. Numerical and experimental results prove that using linear or cubic displacement feedback control the vibration amplitudes can be significantly reduced. The controller can tolerate speed variations, but it always needs to include compensation in order to increase the stability margins of the controlled system. The linear displacement feedback has a better performance at low values of the deflection, whereas the cubic displacement feedback shows a better robustness performance at high values of moving masses and speed variations.