Predictive Control And Dynamic Simulation For Flexible Model Of Hypersonic Vehicle

Hypersonic vehicle has special strategic value in both military and civilian areas, so it has already become a hotspot throughout the world. However, compared to the other aircrafts, the dynamic characteristics of the hypersonic aircrafts will vary considerably over the flight envelop due to their extremely wide range of operating conditions. Furthermore, because of airframe-integrated scramjet utilized and the flight range of high altitudes and big Mach numbers, hypersonic aircrafts are very sensitive to changes in atmospheric conditions. Moreover, many aerodynamic and propulsion characteristics are hard to predict due to the effect of the structural dynamics, propulsion aerodynamics and coupling between them. As a result, the hypersonic vehicle is with multiple variables, strong nonlinearity, fast time-varying, hard input and state constraints, so it is essential to design flight controllers with high non-linear control ability for hypersonic aircrafts.Firstly, based on the review on modeling method of hypersonic vehicle, the motion model and aerodynamic model of pitch channel of hypersonic vehicle are discussed, and motion equations and aerodynamic characteristics are acquired, which is a foundation for subsequent work on controller design and simulation.Secondly, aiming at nonlinear model of hypersonic vehicle, the method of model linearization is studied, and the dynamic characteristics of hypersonic vehicle model are analyzed. Considering small range flight of hypersonic vehicle, a state-space model based predictive controller is designed. The simulation results show that the application of predictive control in hypersonic vehicle is feasible.Thirdly, considering large envelope flight of hypersonic vehicle, two multi-model predictive control schemes are studied. One is velocity based multi-model predictive control method. Improved switching rule chose to realize efficient large range tracking control of flight velocity. The other is velocity and altitude based multi-model predictive control method. The simulation result shows that it could lead to good performance of large range tracking control when both velocity and altitude have a large change.