Research On Altitude And Attitude Control Of Quadrotor Based On Linear Active Disturbance Rejection Control

This paper is supported by the Natural Science Foundation of Fujian Province"Data-Driven High-Altitude Airship Flight Switching Control"(2016J01317)and the Tibet Autonomous Natural Science Foundation of China "Nonlinear Network Control System Stability Study"(2016-ZR-15-25)to study quadrotor's altitude and attitude control.Linear Active Disturbance Rejection Control(LADRC)is used as the main theoretical tool to deal with model uncertainties and gust disturbances in actual flight.The specific research content is as follows:Firstly,the nonlinear dynamic model of the quadrotor is derived from the Newton-Euler formula,and then the principles of the Electronic Speed Control(ESC)and the motor are analyzed and an approximate model is given,which is then used for the controller.The model parameters are measured and estimated to obtain a complete mathematical description of the quadrotor.Secondly,in order to observe whether LADRC can cancel the disturbance and stabilize the aircraft,the above nonlinear model is simplified.Based on the simplified model,LADRC is designed to control the altitude and attitude of the quadrotor,and attitude control is regarded as a tracking problem to re-correct the attitude error.The error is calculated using SO(3)space error instead of the Euler angle error.Finally,the flight simulation of the tracking step signal is performed on the o-riginal nonlinear model,and the root trajectory method in the classical control theory is used to analyze and tune the LADRC parameters,so that the desired time domain index has achieved.The simulation results reflect that LADRC has the advantages of short adjustment time and small overshoot while ensuring stability.At the same time,compared with the effect of cascade PID control,it shows that LADRC can deal with the uncertainty and coupling in the model well,and shows a strong anti-interference ability.