Research On The Control Of Four-rotor UAV Smooth Flight

Multi-rotor unmanned aerial vehicle(UAV)is a new kind of UAV that can take off and land vertically.Its attitude change is achieved by changing the rotor speed.The model of this kind of aircraft is a typical under actuated system due to its own mass,change of moment of inertia and uncertainty of external disturbance,which is a nonlinear system.And there are many variables,strong coupling,so in the development process there are many difficulties.At present,the development of this type of aircraft is a world hot spot.This paper focuses on the discussion of how to maintain a fast and stable flying state of Four-rotor UAV under uncertain conditions.In recent years,four-rotor UAV has attracted attention all over the world due to its convenient operation,low cost and high mobility.It has been widely used in agriculture,logistics,surveying and mapping,military and other fields.Four-rotor UAV is an under-driven nonlinear system,which is easily disturbed by wind field and other factors in the flight process.With the development of the UAV technology,the study of the flight stability for four-rotor UAV increases gradually.The PID control,linear control,nonlinear control,adaptive control and other control methods were applied to four-rotor UAV stable flight application.Some results have been achieved,but there are still some limitations,the main problem is its flight stability and reliability.This paper focuses on how to maintain a fast and stable flight of the four-rotor UAV.On the basis of learning the flight principle of the four-rotor UAV,the mathematical model of the four-rotor UAV is established,and the force analysis of the four-rotor UAV is carried out.An adaptive neural network sliding mode controller(ANNSMC)was designed based on the nonlinear four-rotor mathematical model.The four－rotorr UAV itself has many uncertain factors,so in order to ensure the best quality of the system,particle swarm optimization algorithm PSO is introduced,and PSO-ANNSMC controller is designed.At the same time,MATLAB simulation is carried out.The experimental results show that the four-rotor UAV has better robustness and disturbance resistance under the control of PSO-ANNSMC than that of ANNSMC.In this paper,a stable flight control algorithm for UAV is proposed,and an outdoor flight experiment is designed.This paper introduces the preparation of the flight experiment of the four-rotor UAV and builds the experimental platform.The results of debugging and flight experiments show that the four-rotor UAV has better performance of tracking its attitude and position change when controlled by PSO-ANNSMC.