Research On Modeling And Control Methods Of Hypersonic Vehicle

Compared with the regular aircraft, the hypersonic aircraft has the features ofhigh flight velocity, high flight elevation and high maneuverability, so it is of greatimportance in the both civilian field and military field. Because of the advancedaerodynamic configuration, fuselage-engine integrated design, large flight envelopeand the tremendous changes of flight environment, the hypersonic aircraft has poorstability, serious couplings among the subsystems and biggish model uncertainty,therefore, it’s very necessary to establish a relatively accurate mathematic model anddesign the controllers which have strong robustness.In order to comprehensively learn the flight characteristics of the hypersonicaircraft, both rigid body motion model and elastomer motion model are given byusing the Lagrange method, and then the6-DOF Simulink model is established basedon the existing research results. By using the6-DOF Simulink model, some flightcharacteristics of the hypersonic aircraft are given such as the pitching stability, theflight envelope of longitudinal movement and the motion modes of hypersonicaircraft.By using differential geometry theory, the longitudinal movement model of thehypersonic aircraft can be linearized precisely, and the precisely linear model can begiven, by using which the input-output decoupling is realized. The advantages of theprecisely linear model can be seen by comparing with the control effects of thecontroller which is designed based on the approximate linearization model.For the bounded matching uncertain control problem for the longitudinalmovement of the hypersonic aircraft, sliding mode variable structure controller basedon the dynamic inversion feedback is designed by using both the sliding modecontrol and the dynamic inversion feedback theory, the designed controller has theadvantages of decoupling which is given by the dynamic inversion control androbustness which is given by the sliding mode variable structure control, andachieves good control effects. For the bounded unmatching uncertain controlproblem, both adaptive backstepping and sliding mode variable structurebackstepping are used to design the controllers which have strong robustness and canalso restrain the disturbance caused by the uncertainty.For the case in which the dynamic information of model is completely unknown, total energy control theory is used to design the total energy control system. Thesimulation results indicate that the controller designed by the total energy controltheory has better control effect and stronger robustness without using the dynamicinformation of the hypersonic aircraft model.For the trajectory planning problem in the ascending stage of the hypersonicaircraft, Gauss Pseudospectral method is used to convert the primal problem to anon-linear programming problem, and then solve the a non-linear programmingproblem by using the algorithm of SNOPT, and get very good optimization resultsand the corresponding control strategy which save a large amount of fuel.The conclusion of this paper and the perspective in future work are given at theend of the paper.