Research On All-course Parameter Online Identification Method Of Boost-Gliding Vehicle

For the offensive and defensive confrontation system,the boost-gliding vehicle has become the center of attention,because of its striking effect on attack.In order to reduce the reaction time of defensive system and increase the survival probability and penetration probability of aircraft,a low trajectory mode which fly in the atmosphere all the way that can be covered by the curvature of the earth has gradually become the common trajectory mode of boost-gliding vehicle.However,the aircraft fly in the atmosphere all the time,the difference of motor parameter and aerodynamic parameter and the external atmospheric parameter have great impact on the flight status.The accumulated deviation on flight path is a great burden for the guidance and control system and seriously affect the attack precision.In order to solve the problem of parameter deviation in the whole process of the boost-gliding vehicle,this paper systematically study the online identification of motor parameters,atmospheric parameters and aerodynamic parameters.For parameter online identification of the boost-gliding vehicle,it is necessary to consider its own characteristic and its flight mission.In this paper,the whole trajectory of the boost-gliding vehicle is established,and the terminal guidance and control system is designed.Aiming at attacking the target 350 km away and hitting the target at a high angle of fall,the aerodynamic shape is designed,aerodynamic coefficients are calculated,flight trajectory is designed,terminal guidance and controller parameter selection are completed.These preparations are the basis of the follow-up parameter online identification method research.In order to solve the ground to flight difference of solid rocket motor and its influence on the flight state at the shutdown point,this paper proposes a strategy to identify motor parameters online and predict the flight performance.Through the analysis of internal correlation between motor parameters,establish the calculation model of the nozzle throat diameter and the propellant burning rate.Based on the realtime measured data from the missile-borne sensor,this model can calculate the throat diameter and burning rate,and then use the recursive least square algorithm to identify the model parameters of throat diameter and burning rate.Based on the identification results,shutdown time and thrust-time characteristics can be predicted.The simulation shows that this method has high identification and prediction accuracy,and provides a feasible solution for the online identification and prediction of the performance parameters of the solid rocket motor.The deviation between atmospheric environmental parameters and aerodynamic parameters are important factors which lead to aerodynamic deviation.In order to reduce the calculation error of the Flush Air Data System,the effects of measurement error on the calculation results of the Flush Air Data System are studied.Based on the output data of Flush Air Data System and the controller established in Chapter 2,aerodynamic parameters are identified and the accuracy and efficiency of different identification methods are compared.Finally,check the safety of excitation signal.Based on the flight test data of the test rocket,Extended Kalman Filter and Unscented Kalman Filter were selected as the identification methods of aerodynamic parameter.To identify its aerodynamic force,the flight test data are analyzed to verify its credibility,then the online identification results based on the measured data are analyzed,finally summarize the application conditions of the online identification of test rocket and provide some suggestions for the subsequent practical application.The work of this paper can provide a solution to the problem of parameter identification for the whole flight of the boost-gliding vehicle,and provide reference for the research of online trajectory planning,non-programmed guidance and control.