Optimum design of structures with disturbance suppression by H infinity control - (Output feedback case)

An optimum design problem of structures, considering control performance, i s presented. We assume that a structure is subjected to initial loads and t ime-varying disturbances and is controlled by an H-infinity controller to s uppress the effect uf disturbances. The purpose of the design is minimizati on of an objective function that represents the effect of the initial loads under a constraint imposed on the weight of the structure. We have already reported a solution to this problem using a state feedback H-infinity cont roller. However, the state is not always measurable in real structures. For this reason, we adopt an output feedback H-infinity controller. Determinis tic initial loads and statistically known initial loads are considered, and the objective function for the control system is proposed in the case that the initial loads are known statistically. A numerical example of the stru cture of a 3-D truss is presented.