Path Planning,Guidance And Control For A Hypersonic Veichle

With the requirements of reconnaissance in terms of international strategic increasing,it is quite necessary to enhance the flight speed of reconnaissance aircraft.Since the 9·11 incident occurred in United States in 2001,Pentagon proposes the concept of “global fast strike” which aims to strike any target on the earth within an hour and makes a considerable investment in the research of hypersonic aircraft.In order to cope with the international situation,it is of necessary to invest research in the framework of hypersonic aircraft for our country so as to provide certain engineering and theoretical basis for developing prototype hypersonic aircraft.The work of this dissertation mainly concentrates on two topics in the framework of hypersonic aircraft.One is the cruise control and automatic landing control of the hypersonic aircraft with the engine works.The other topic is,assuming that the engine is flameout,the path planning,guidance and control of the hypersonic aircraft during the distress landing.By researching the characteristics of various states of hypersonic aircraft,author proposes the specific research courses and the corresponding solutions respectively.The primary work and research results are shown as below:1.The research on the cruise control of hypersonic aircraft with the speed of 6Ma at the altitude of 30 km.There are existing problems such as aerothermoelastic,coupling between fuselage and propulsion system as well as the matched uncertainties,unmatched uncertainties and external disturbances during the hypersonic aircraft cruising.In order to handle these problems,this dissertation organic combined the adaptive Backstepping and sliding mode control together innovatively.Compared to the traditional Backstepping sliding mode control,the proposed method in the dissertation could not only deal with external disturbances,matched uncertainties as well as unmatched uncertainties,but also reduce the chatter caused by the sliding mode control effectively using Backstepping method.The global stability of the method is proved by theoretical derivation and the effectiveness of the method is verified by the digital simulation.2.The research on the guidance and control of the hypersonic aircraft during automatic landing.Landing is the final phase and it is also the most dangerous one in flight which is primary affected by the atmospheric environment including wind shear,gust and wind disturbance.In terms of the control problem of this phase,author combines the adaptive Backstepping sliding mode control and dynamic surfaces innovatively and it solves the complexity increasing problem caused by system order increases using Backstepping control method.Finally,utilizing the designed control realizes the automatic landing by digital simulation.3.The research on the guidance system design for the unpowered hypersonic aircraft.Starting with the guidance law design for the distress landing,form the perspective of theory,this dissertation proved the stability of the traditional line-of-sight guidance method innovatively.Making some improvements to the traditional line-of-sight guidance method instructed by the ideal of single neuron PID control and the improved method is adaptive.The digital simulation results show that whether there are wind disturbances or not,the tracking accuracy of the adaptive guidance system is superior to the traditional line-of-sight guidance method.In addition,in order to track the path of distress landing,this paper designs a switching plane to ensure the smooth transition between the two guidance laws and it ensures the aircraft is able to track the Dubins path in 3 dimensional spaces.Finally,the effectiveness of the proposed method is verified by digital simulation.4.The research on path planning of distress landing for hypersonic aircraft.Instructed by the idea of space partition,this dissertation solves the path planning based on Dubins curve at the phase of approach and returning.Namely,when the aircraft in a certain range of airdrome,the engine flamed out at any position and the aircraft heading in arbitrary direction,the proposed method can always generate a glide path which ensures the aircraft could fly to the landing window precisely.This method has lower computational complexity,just requires straight-forward logic judgment and small amount of calculation to find the optimal glide path,so that it suitable for path planning of unpowered distress landing process.Finally,the effectiveness of the proposed method is verified by digital simulation.5.The research on automatic landing guidance control for unpowered hypersonic aircraft.In terms of unpowered automatic landing,this dissertation designs the unpowered glide path composed of a straight line and a circular arc as well as the corresponding path guidance laws innovatively.Due to the longitudinal control of unpowered aircraft is the configuration of airspeed control,using the circular arc trajectory could calculate the acceleration readily which is requisite in longitudinal control.Finally,the automatic landing of the unpowered aircraft is realized in the digital simulation.