Research On Modeling And Control Of Hypersonic Vehicle

The science and technology are developing rapidly in recent years.Every country wants to catch the opportunity so they all invest a large of money in science and technology.Especially in military technology,it plays an important role in the safety of a country.Stepping to the 21 st century,more and more countries make a focus on aerospace technology that can directly decide the strength of a country in military and technology which are experiencing a rapid development.In recent years,to contend for the advantages of the space from 20 km to 100 km that has no any aircrafts here,the supersonic vehicles have become an important study area in the word.America and Russian,depending on his powerful base of industry and technology,get ahead of other countries.Although our country makes a great success in this area,the distance between our country and developed counties is not inclined.We need to make more progress to get in same line with them,even win them.We study the model of air-breathing supersonic vehicles and simplify the complex original model to control-oriented in this article.Based on simplified model,we study the aerodynamic characteristics and control methods.Firstly,we analyze the fore and momentary on supersonic vehicle,using the theory of shock waves and expansion waves.Based on this work we obtain the longitudinal model of supersonic vehicle.By using the curve fit result of other articles for fore and momentary,simplify the model and get control-oriented model.Then,for the simplified model,by the means of the small perturbation linearization and curing factor,the nonlinear model of supersonic vehicle is linearized in a trim condition.Base on the linear model in the trim condition,we analyze the short and phugoid mode,the coupling of aerodynamic fore,the decoupling between pitch angle and flight angle and the characteristic of instability and non-minimum phase.At the end,a state feedback controller and pitch angle stability loop and attack angle stability loop are designed for the unstable longitudinal model.For the characteristic of strong coupling and nonlinearity,a optimistic controller by the method of feedback linearization is designed.It can track the speed and height order exactly.