Continuous sliding mode control of a TV transmission tower under stochastic wind

An active mass damper has been designed to be installed on the upper observation deck of the 310 m Nanjing TV transmission tower in China in order to reduce the acceleration response under strong wind gusts. In this paper, we present a continuous sliding mode control (CSMC) strategy using dynamic output feedback for application to the active mass damper system based on acceleration feedbacks. Emphasis is placed on the performance and practical application of active controllers, such as actuator limitations and noise pollution. A systematic modulation of the control effort for the CSMC controller is proposed by introducing a prefilter to the control force. The wind loads acting on the tower are defined by a cross-power spectral density matrix. The spatial correlation of wind loads is accounted for in the design of the observer for the CSMC controller. The power spectral densities and rms of acceleration responses of the tower equipped with an active mass damper have been computed. Simulation results demonstrate that the CSMC strategy is suitable for full-scale implementations of the active mass damper and its control performance is quite remarkable.