Study On Quadrotor Drone Flight Stability Control System

The quadrotor drone have attracted the attention of many experts and scholars at home and abroad because of its excellent performance,low price,and being able to replace people to complete many dangerous and inconvenient tasks.However,crashes and explosions of quadrotor drone generally occurred.The instability of the quadrotor drone flight control system remains to be further studied.In this paper,the quadrotor drone is firstly subjected to force analysis and mathematical model is established.Aiming at the characteristics of nonlinear,strong coupling and uncertainty of quadrotor drone,experiments have found that in terms of attitude angle and height control,the cascade PID has a large amount of overshoot and a long stabilization time.In the quadrotor drone flight control stability is not good.In the actual flight process,the quadrotor drone parameters and the external environment often change.The drone is subject to too many internal and external disturbances.Once the interference has affected the stable flight state of the quadrotor drone,the cascade PID will need to reset the parameters to adapt to the external environment in real time,so the control effect is poor.After analyzing the shortage of the cascade PID control in the stability control of the quadrotor drone,an auto-disturbance rejection controller(ADRC)that can largely compensate for the disadvantages of the PID controller was selected.First,a transition process(Tracking Differentitor,TD)is arranged for the input signal,and the given signal is preprocessed so that the error gradually changes instead of mutating.The extended state observer(ESO)in the ADRC is used to estimate various kinds of error interference inside and outside the system and to determine and linearize the uncertain and nonlinear interference.The ESO is equivalent to the integral action in the PID but is more systematic and accurate than simple integration.The nonlinear state error feedback(NLSEF)arranges the transition process for the input signal and solves the contradiction between rapidity and overshoot in the control process.The NLSEF combines the ESO with the TD in a nonlinear way.After the two controllers are designed,comparing the two controllers in the attitude and height control effect of the quadrotor drone,it can be seen that the ADRC is better in the stability control of the quadrotor drone.After completing the design of the quadrotor drone control algorithm,a hardware physical platform for the quadrotor drone flight control system was independently designed and built.The actual flight experiments were performed using the ADRC algorithm with good control effect obtained in the previous article.The quadrotor drone can fly smoothly.