Research On Reliable Flight Control For Variable-load Quadrotor UAV In Agricultural Protection

With the rapid growth of smart agriculture in recent years,variable-load plant protection UAV have gradually been favored by more and more people because of their simple structure,good maneuverability,high flexibility and easy maintenance.However,due to the particularity of its work,the variable-load plant protection UAV is often affected by factors such as changes in load mass,external environmental disturbances and actuator faults,forcing its tracking stability to a predetermined trajectory to be reduced and even crashes.Therefore,in view of the above-mentioned potential safety hazards,this paper will carry out the following system reliability control research on the variable-load plant protection quadrotor UAV spraying pesticides as the object:First of all,according to the time-varying load mass of the variable-load plant protection quadrotor UAV,the flight principle is analyzed and combine with Newton’s Euler theory,the mathematical model is established.And a mass estimation mechanism is designed to estimate in real time the disturbances brought by the variable mass to the system.At the same time,considering the influence of actuator bias fault and efficiency loss fault on it,the fault model of the variable-load plant protection quadrotor UAV system is established.Secondly,based on the system model,in the presence of external disturbances and disturbances caused by internal load mass changes,acting on the variable-load plant protection quadrotor UAV at the same time,the variable-load flight system is divided into two subsystems: position and attitude.Combination with non-singular fast terminal sliding mode control and adaptive estimation algorithm,two controllers for position and attitude of the variable-load flight control system are designed respectively.Through MATLAB comparison experiments,it is verified that the designed anti-disturbance controller ensure the system track the preset trajectory stably and quickly.Finally,based on the system fault model,according to the situation of actuator bias fault and efficiency loss fault in the variable-load plant protection quadrotor UAV system,adaptive fault observers are designed to estimate various sudden faults,and the estimated fault information is compensated in the designed non-singular fast terminal sliding mode fault-tolerant controller.Through multiple groups of MATLAB simulation comparison experiments,it is proved that the designed fault-tolerant controller can make the variable-load flight control system tolerant the influence of different faults and increase its flight reliability.