Research On High Performance Control Of High Speed Aircraft In Complex Environment

Nowadays,the competition among the world powers in the field of aviation and astronautics is becoming more and more intense.Among this field,the hypersonic weapons with great tactical practicability and strategic deterrence are the key development objects.The attitude tracking control of hypersonic aircraft is a hot research object in the field of flight control.Hypersonic vehicles usually work in extremely complex flying environment due to their extremely high altitude,which greatly increases the uncertainty and seriously affects the flight performance.Such high speed aircraft is usually faced with uncertainties including modeling error,aerodynamic parameter error and external disturbance,and at the same time has the characteristics of strong three-channel coupling system.So how to achieve good and fast attitude control has become the main research direction in the field of aircraft control.The following researches are carried out:Firstly,for the general high speed aircraft model,the coordinate system and its transformation relationship are analyzed and deduced,and the aerodynamics of the aircraft are analyzed and solved to obtain a 6-DOF model,which is finally simplified into the corresponding affine nonlinear attitude control model.Secondly,from the perspective of the disturbance compensation for complex environment disturbance and uncertain parameters under the condition of attitude control demand,by respectively introducing a nonlinear disturbance observer and adaptive neural network these two tools to estimate the uncertainties of affine nonlinear model smoothly.So we can compensate uncertainties in the process of the control law design,to enhance the stability of the control system.Then,from the perspective of state constraint control,the barrier Lyapunov function is introduced to realize the prescribed performance constraint backstepping control for the output,and the attitude control under the intermediate variable angular velocity constraint is realized through the constraint virtual control quantity combined with the auxiliary system.Finally,from the perspective of stability augmentation control,the original control system model is separated and extract the error model from it.The stability augmentation controller is designed by combining with the adaptive dynamic programming control,so that the tracking performance of the control is further improved.