Robust Attitude Control For Hypersonic Vehicles

The Hypersonic vehicles are designed integrated. The coupling exists between the airframe and the engine, also in the pitch channel, the yaw channel and the roll channel. During the whole flying period, the vehicle experiences the vast change of the altitude, and the velocity changes frequently. Fast time-varying and strong coupling are the main characteristics of the whole flight. After the wind-hole data model being analyzed, the dissertation designs robust controller based on the parametric method. The main works are listed as follows:1. Based on the given data file, the relationships between the inputs and the outputs are analysed. The analysis results are given in tabular form. The equilibrium point is calculated with the data file, which is set as the feature point of the dynamic equation linearization and the control system design process. Using the linearization method with small perturbations, the nonlinear dynamic equations are linearized around the feature point based on the coefficient freezing method. The free-perturbation movement is analyzed, which is unstable.2. The model of the hypersonic vehicle attitude control system is built on the feature point. The aerodynamics and the propulsion are linearized with the coefficient freezing method, and projected in the airframe coordinate system. After simplified, the mathematical model is built, which is decoupled into the pitch/yaw model and the roll model. The synthesized performance index is designed and parameterized, including the robust index, the track function index and the interference suppression index.3. The flight controller is designed based on the Eigen structure assignment. The controller includes the state feedback controller and the feedforward tracking controller. Fixed-point simulation is made for the pitch channel. The results show that the designed controller ensures the track on the given guidance signals. At last, the trajectory simulation is done. The results show that the controller guarantees the stable cruise and is able to avoid obstacles with maneuvering flight.