Frequency Domain Optimal Control of Wind-Excited Buildings

An optimal frequency-domain approach to active control of wind-excited buildings is proposed in which the H2 norm of the transfer function from the external disturbance to the regulated output is minimized. A wind-excitation model established by factorizing the cross-spectral density matrix of the wind fluctuation is included in the control design. The control of a 60-story building under an along-wind excitation by one mass damper, two mass dampers, and active tendon mechanisms is presented in the numerical examples. As an improvement over previous results in civil-engineering structural control studies, measurement and minimization of building accelerations is achieved. The effects of using constant and frequency-dependent weighting functions in the control design are also shown. In this case, the frequency-dependent weighting functions are designed based on the frequency domain response characteristics of the building. The frequency-domain-based-design approach is shown to be both flexible and powerful.