Variable-gain control applied to aerodynamic control of bridge deck flutter

A method of suppressing flutter of a very long span bridge is presented in this paper. The control system consists of actively controlled surfaces which by torsional movement generate stabilizing aerodynamic forces. The unsteady aerodynamic forces, acting on the bridge deck, are approximated by the rational function approximation and the frequency independent equation of motion is derived. The dependence of the system on mean wind speed limits the efficiency of application of the conventional constant gain optimal feedback control. The improvement in control effectiveness is obtained by proposed variable-gain concept. The output variable-gain approach is formulated in terms of mathematical optimization problem and necessary conditions are derived