Active/Robust Control of Longitudinal Vibration Response of Floating-type Cable-stayed Bridge Induced by Train Braking and Vertical Moving Loads

The active/robust control of the longitudinal vibration response of the deck of floating-type cable-stayed bridges induced by train braking and vertical moving loads has been investigated in this paper. Controlled objects of large structures such as long span bridges generally have high orders of controlled variables and this may lead to high costs and complications of controllers. Hence, a reduced controlled model of lower orders based on a modal reduction method has been proposed. Because the controller designed from the reduced model may influence the control effect of the original controlled system; the stability and error of the reduced model have been studied. The results indicate that when a sufficient number of modals are included in the model, the influence is very small. In view of parameter uncertainties in long span bridge structures, the active robust control equations based on frequency uncertainties have been derived, and the active robust control of longitudinal vibration responses of the deck, which are induced by train braking and vertical moving loads, has been simulated for Tian Xingzhou Yangtze River Bridge in China. Simulated results have been compared with results of the active control based on the linear quadratic regulator (LQR) algorithm. Comparisons have shown that the robust control is more effective and efficient than the active control based on the LQR algorithm.