Across-wind response of a tall building with active tuned mass damper using Linear-Quadratic-Gaussian controller

Modern tall buildings use lighter construction materials that have high strength and lower stiffness, and are thus susceptible to excessive wind-induced excitations, which can result in occupant discomfort and structural safety concerns. Recently, a number of studies have been conducted to investigate buildings that use actuators as an active control force based on the modern control theory of linear quadratic optimum algorithms. The optimal control law of a linear-quadratic-Gaussian (LQG) controller with an active tuned mass damper (ATMD) is used to reduce the across-wind response of a tall building. The ATMD model consisted of a second mass with optimum parameters for the tuning frequency and damping ratio of the tuned mass damper (TMD) under a stationary random load. A fluctuating across-wind load acting on a tall building was treated as a stationary Gaussian white noise and simulated numerically in the time domain using the across-wind load spectra proposed by Kareem (1982). This simulated across-wind load was used to calculate the across-wind responses of tall buildings with and without ATMD using an LQG controller. By comparing the respective root mean square (rms) responses, it was found that the numerically simulated across-wind responses without ATMD provided a good approximation to the closed form response and the reduced responses with ATMD and LQG controllers were estimated by varying the values of the control design parameters.