Abstract:

For a model of an air-breathing hypersonic vehicle subject to input constraints, this paper is concerned with the robust gain-scheduling control. For dealing with the modeling error and saturation nonlinearities associated with the vehicle model, the standard control problem for linear parameter-varying (LPV) systems is extended into the robustness framework with structural perturbation of time-varying parametric, dynamic  uncertainties and saturation nonlinearities. Based on the characterization of model uncertainties and saturation nonlinearities via integral quadratic constraints, the robust gain-scheduling control algorithm is presented in terms of scaled linear matrix inequalities (LMI). In order to conduct a gain-scheduling control system design, an LPV model of the vehicle is developed. Based on the multi-time scale property, an inner/outer loop control structure consisting of attitude loop and trajectory loop is proposed. The inner-loop achieves tight attitude control and overcomes actuator saturation. The outer-loop achieves accurate trajectory tracking. The gains of the controllers are scheduled with dynamic pressure and Mach number to achieve large-span maneuver flight control. Nonlinear simulation results are presented to verify the algorithm and application.