Research On Reentry Trajectory Guidance Based On Aerodynamics Correction

Since the concept of Hypersonic was proposed,due to its great military and economic value,many countries have poured money into it.In this dissertation,reentry trajectory guidance of hypersonic vehicles are studied.Firstly,according to the kinematics and dynamics characteristics of the aircraft in the reentry process,the movement of the aircraft is analyzed,the mathematical model of the law of motion is established.Then,through the analysis of the effects of the reentry process,various constraints and terminal constraints are obtained.these constraints are calculated to obtain the safe flight area of the aircaft in the reentry process.That's the flight corridor in the process.And then we ignore the coefficients which has little influence,deduce the relationship between residual and drag acceleration.Thus,an onboard reference trajectory planning algorithm is designed.Then,to solve the problem of the aerodynamic parameter deviation in the guidance we introduce an estimation and correction method of aerodynamic parameter which can improve the precision of the calculation of drag acceleration.Thus,the accuracy of the guidance is improved.Then,we analyzed the standard trajectory guidance and the prediction correction,combing aerodynamic characteristics of lift aircraft,desigend a trajectory tracking law for longitudunal plane using feedback linerization technology,and introduced the lateral guidance strategy based on the heading angle deviation corridor.Finally,for the aircraft we studied,the reentry guidance method is simulated to verfy its validity in the case of large aerodynamic deviation.Then,for the deviation in the initial state,Monte Carlo simulation is performed to verfy the guidance method is not sensitive to the initial state.Also,for the deviation in the aerodynamic parameter of the reenty process,Monte Carlo simulation is performed to verfy the guidance method roustness.