SUBSTRUCTURE-BASED CONTROLLER-DESIGN METHOD FOR FLEXIBLE STRUCTURES

In this paper, a decentralized procedure for designing controllers for flexible structures is presented, With decentralized control design m ethods, the system to be controlled is divided into subsystems for whi ch controllers are designed, These are then combined in some way to fo rm a controller applicable to the original system, In the proposed met hod, the structure to be controlled is considered as a collection of s ubstructures. For each substructure, a subcontroller is designed with linear quadratic optimal control theory, although any method can be us ed, Then, a controller synthesis scheme called Substructural Controlle r Synthesis (SCS) is used to assemble the subcontrollers into a system controller, which is used to control the whole structure, The propose d method is closely related to component mode synthesis methods of str uctural dynamics and to decentralized control using overlapping subsys tems, It is attractive because, unlike most decentralized methods, an explicit decomposition is generally not needed since substructure mode ls often exist a priori, Also, an SCS controller is very adaptable bec ause each subcontroller is designed based on an individual substructur e model; therefore, the controller can be updated very economically if part of the structure changes, A plane truss example bused to illustr ate the proposed method.