The Study Of Application Of Active Disturbance Rejection Control In Attitude Control Of Flight Vehicle

Taken the design of attitude control system of flight vehicle as the research object,this paper is devoted to provide new approaches to solve the attitude control problem of large scale uncertainty.The source,purpose and significance of the task are summarized in the paper firstly.The state-of-the-art theories of advanced control methods and active disturbance rejection control method,as well as the development trend and application are briefed in the literature review.The current research foundation and shortcomings,especially the lack of practicality are also discussed.The theoretical basis of the active disturbance rejection control method is studied and summarized.The analysis and example simulation of arranging the transient dynamics,extended state observer and state error feedback control law are emphasized in the paper.Furthermore,the thought of model assistant is led to through explaining how to tune parameters of linear extend state observer.Finally,the decoupling control for MIMO systems with active disturbance rejection control method is studied.Then the design of classical control method based on tuning gain and network correction is studied.By using the method of ignoring coupling,the gain and network are designed separately,and then the characteristics of frequency domain are analyzed.Finally,6-DOF simulation is completed.The traditional control method is simple and the engineering applicability is strong.But when the range of parameters increases,the difficulty of the design also increases correspondingly.The scheme design of linear active disturbance rejection control method constructed by classical control method and linear extended state observer is studied.In the paper,the specific forms of the active disturbance rejection control additional network are deduced,and then the influence of the active disturbance rejection control network on the closed-retreat system is analyzed with a concrete example.The analysis results show that the active disturbance rejection network can improve the steady state precision,and the network is a time-varying network with “self adaptability”,so it can improve the robustness compared with the classical control method.Finally,the results of the analysis are validated by 6-DOF simulation.The application of nonlinear active disturbance rejection controller is studied.The second order nonlinear attitude equations are transformed into series of two first nonlinear equations,thus the reduced order design is realized.The observational pressure of the observer is reduced by making full use of the known information of the model according to the model-assisted principle.The controller is designed by multivariable decoupling control,and the conversion relationship between control quantity and virtual control quantity is given.The result indicates that the nonlinear active disturbance rejection control method has a good adaptability to the wide range of uncertainties.The control method has good adaptability to the unexpected disturbance in the flight process,and the controller has better robustness.