Parametric approach for longitudinal attitude control of a hypersonic vehicle

In this paper, a parametric approach for longitudinal attitude control of a hypersonic vehicle is presented. Firstly, according to the complicated aerodynamics characteristic of a hypersonic vehicle, the model of the pitch channel is treated as an interval system in order to cope with parameter uncertainties. Secondly, by employing robust stability analysis and parametric control theory, a parameterization of state feedback controllers for the interval autopilot system is obtained. Thirdly, by appropriately optimizing the free parameters in the robust stabilizing controller, the H2 norm of the disturbance-output transfer function is made sufficiently small over the system parameter intervals. A simulation example of the pitch channel of a hypersonic vehicle demonstrates that the system achieves good performance with external disturbance despite the aerodynamical parameters vary in a large scale.