| This dissertation investigates linear time-varying integrated control/diagnostic system analysis and synthesis. By studying the generic form of integrated control/diagnostic system, i.e. the 4-parameter controllers, this dissertation extends the existing stability condition for linear time-invariant 4-parameter controllers to the linear time-varying case. Based on this extension, this dissertation further studies the robustness of linear time-varying 4-parameter controllers, and provides a necessary and sufficient condition under which linear time-varying 4-parameter controllers can be robustly stabilized. In parallel with this robustness study, this dissertation also investigates the H-infinite design of linear time-varying 4-parameter controllers, and provides a two-step design procedure. In this two-step design procedure, first an initial linear time-varying compensator is introduced. This compensator transforms the original time-varying dynamic into an equivalent time-invariant dynamics. Second, based on the compensated plant, the standard linear time-invariant methodology is used to find the optimal 4-parameter controllers. A spacecraft attitude control problem is used to illustrate this technique. |
