Research On Attitude Control Of Complex Aircraft Based On ADRC

Deformable aircraft can adjust its shape and structure in real time according to its environment and mission,so that its aerodynamic shape can adapt to a wider range of flight airspace and velocity domain.Because the aerodynamic shape of the deformable aircraft is changeable,the force of the aircraft is complex,and the dynamic parameters of the model change sharply in the deformation process,which brings difficulties to the model establishment and attitude control design of the deformable aircraft.This paper takes this kind of problem as the research background,takes the variable span aircraft as the research object,and carries out the dynamic modeling of the deformed aircraft and the design of the attitude controller of the pitch channel.The main research work is as follows:In order to describe the deformation process of the aircraft,this paper first established the required coordinate system,based on the Newton-Eulador rigid body dynamics method,established the six-degree-of-freedom dynamic model of the aircraft in the launch system,and gave the additional force in the launch system.The expression of is prepared for numerical simulation;at the same time,ignoring the influence of the rotation of the earth and the curvature of the earth,a multi-rigid-body dynamics model of the deformable aircraft in the shell system is established.Based on the hypothesis of wing mass and deformation symmetry,the kinematics model of the deformed aircraft pitch channel is simplified,and the kinematic model support is provided for the subsequent study of attitude control methods.At the same time,based on the aerodynamic data estimated by the aerodynamic software,the influence of the deformed aircraft wing on the aerodynamic characteristics of the aircraft pitch channel at different deformation speeds is analyzed,and the influence of deformation on the aerodynamics is further explored.At the same time,when the rudder is fixed and the aircraft is uncontrolled,the dynamic response characteristics of the pitch direction of the deformed aircraft in the nonlinear simulation under different deformation speeds are analyzed.It is revealed that when the aircraft attitude is stable or in the low-speed state,the additional force and torque can be ignored in the linearization process of the aircraft model.Based on the aerodynamic study of the deformation process and the dynamic model of the deformable aircraft,the control method combining gain scheduling strategy and PID control is studied,and the pitch channel angle of attack control system of the deformable aircraft is designed.Through the simulation of the deformation process of the pitch channel of the deformed aircraft,the effectiveness of the attitude control of the pitch channel designed by the combination of gain scheduling strategy and PID control is verified,and the attitude adaptive control is realized.At the same time,it is further proved that the influence of additional force and additional torque can be ignored when the attitude of the aircraft is stable,And when designing the pitch channel control loop,it is regarded as interference.At the same time,the attitude controller of the deformable vehicle is designed based on the active disturbance rejection control method.Based on the linear active disturbance rejection control method,the internal unmodeled state and external disturbance of the deformable vehicle are estimated by the extended state observer,and the stability of the LADRC controller is analyzed by using the Lyapunov stability theory,The effectiveness an d robustness of the attitude controller designed based on LADRC are verified by numerical simulation.