Research On The Attitude Control Algorithms Of Quad-rotor Uav

The unmanned aerial vehicle is divided into two types, because of simple structure, cheap and can be operated easily, the quad-rotor UAV has been used widely. The attitude control algorithm is th e key to ensure the stability of the vehicle. Therefore, to research the attitude control algorithm is very important.In this paper, the attitude and MEMS sensors of the quad-rotor UAV have been analyzed. The nonlinear mathematical model and the dynamic s ystem model of the quad-rotor UAV have been derived. The position controller and the attitude controller have been designed by PID algorithm. Finally, the controller has been verified by simulation. The result of the simulation shows that the quad-rotor UAV can be controlled by PID control algorithm.The attitude feedback information of the control system is got by the solution of the quad-rotor ’s dynamics model in simulation, but the attitude feedback information of practis UAV is got by gyroscopes, magnetometers and accelerometer. Therefore, the attitude estimation algorithm which is based on the extended Kalman filter calculation method or unscented Kalman filter algorithm or improved complementary filter is designed. The accuracy of the three kinds of attitude estimation algorithm have been validated by simulation. The results of the simulation show that the precision of all of estimation algorithm of attitude angle is high, but the algorithm which is based on the improved complementary filtering algorithm can reduce the computation of the system and reduce the difficulty of realization, so it is more suitable for low cost processor system.The chip STM32F427 has been carried out as the processor, and the platform of the quad-rotor UAV has been built, hovering and flying movement experiment has been carried out by using the UAV platform. The results of the experiment show that the designed control system and the attitude esti mation algorithm can ensure the UAV to flight stability.An environment monitoring system for detecting the concentration of atmospheric PM2.5/10 has been designed. The PM2.5/10 laser scattering apparatus has been equipped to collect atmospheric data, the data is displayed and preservated in the development interface of the computer which is devoloped by QT.