Research On Control System Of Quadrotor Uav Based On Variable Universe Fuzzy PID

In recent years,the development of UAV(unmanned aerial vehicle)is booming,which has been widely concerned in various fields,especially the quadrotor UAV,which has a wide range of application scenarios,such as earthquake relief,forest fire prevention,farmland plant protection,power inspection,film and television production,etc.Quadrotor UAV has been greatly developed due to its advantages of flexible control,simple structure,low cost and high reliability.Flight stability is the most important performance of quadrotor UAV,and stable flight requires a stable control system.But its dynamic model is complex,nonlinear,strong coupling,time-varying system parameters and so on,which makes the flight control difficult.The effect of traditional PID algorithm is not ideal.Fuzzy control algorithm has good control effect for nonlinear system,and has strong anti-interference ability.Therefore,this paper carries out the research and improvement of fuzzy control algorithm for quadrotor UAV.In this paper,the flight principle of quadrotor UAV is analyzed,and its control model is established.According to the control model of quadrotor UAV,the system simulation model of quadrotor is built in MATLAB/Simulink.Three control schemes,cascade PID,fuzzy PID and variable universe fuzzy PID,are designed and applied to the system simulation of quadrotor UAV.Fuzzy PID algorithm can adjust P,I and D parameters in real time through self-learning,improve the adaptive ability of the system and solve some nonlinear problems.Variable universe fuzzy PID adds variable universe optimization mechanism on the basis of fuzzy PID,adjusts the scope of universe in real time through expansion factor,improves the stability of the system,and has good control effect.Through the comparison of Simulink simulation results,it is proved that the variable universe fuzzy PID has good performance,strong anti-interference ability,and the fuzzy PID effect takes the second place.In order to verify the effectiveness of variable universe fuzzy control in quadrotor UAV control,a test platform based on Pixhawk is further built.The hardware modules are selected,and the program architecture and attitude control of PX4 native firmware are deeply studied.The variable universe fuzzy control algorithm is transplanted to the attitude control of PX4 firmware.On the basis of the above,the flight test is carried out on the built quadrotor UAV test platform to verify the control system and control algorithm designed in this paper.