Design And Realization Of Flight Control System For Quadrotor

Quadrotor with a new structure,high performance and flexible features has been widely used in military and civil areas,meanwhile quadrotor has a broad business prospects.It is a typical nonlinear system,not only has the characteristics of underactivity,strong coupling,but also has complex aerodynamic characteristics,quadrotor has high research value and become many experts and scholars concerned about the research object.In this paper,the control algorithm is taken as the core,and the problem of model uncertainty and external disturbance is studied.Based on the sliding mode control,which is not sensitive to the internal parameters of the system and unknown interference,non-singular terminal sliding mode control method,multi-mode sliding mode control method and feedback recursive control method are proposed.The main contents are as follows:Firstly,the flight principle of the four-axis aircraft is introduced,and its aerodynamic characteristics are analyzed according to the relevant theory.The dynamic model is established according to the Newton-Euler formula and the Euler-Lagrange equation.At the same time,the physical meaning of the relevant parameters in the model is established.Secondly,in order to solve the problem that the existing NTSM attitude control method has the slow convergence rate,the sliding surface of the higher order term is constructed under the requirement of non-singularity,and the exponential term is added to the design of the terminal attractor,the NTSM attitude controller with fast convergence capability was designed.Due to the use of switching items,to avoid the buffeting and to strengthen the robustness of the system;At the same time,it is proved that the system has fast convergence and stability in the global scope.Once again,based on the theory of sliding mode control,the multi-modal design concept is used to design the switched sliding mode attitude control law with the characteristics of linear sliding mode and NTSM,so that the system state can be state to run,while ensuring that the system arrival time and sliding time are limited,to achieve a global rapid convergence.At the same time,the outer ring position controller adopts the new back stepping design,which is simple and effective,which reduces the difficulty of engineering realization.Finally,based on the above control strategy,the flight test method is designed,and the flight test platform is built through the selection of components.The attitude control experiment is carried out after repeated debugging parameters.