Research On Attitude Measurement And Control Method Of Oblique Cross Vehicle

Four-rotor aircraft,a kind of UAV with stable performance,unique shape,and function of vertical take-off and landing,possesses wide application prospects in aspects of civil use and military.The oblique cross-aircraft is a structural deformation of conventional four-rotor aircraft with broader scope of viewing angles and is more suitable for aerial photography.A brand new UAV was designed through the study of aircraft modeling,attitude measurement and control method of the aircraft.The main research contents and achievements included:1.According to the flight principle,the Newton-Euler model was used to model of the dynamics of the aircraft,which was based on the physical analysis of the oblique cross four-rotor physical model.The dynamic model was simulated and verified in the MATLAB /SIMULINK environment.2.The aircraft control system’s overall architecture and hardware circuit design were completed based on the controller,attitude acquisition and motor drive modules.The attitude acquisition was done by the sensor MPU6050,the magnetometer AK8975,the barometer MS5611 and the ultrasonic module,and the main controller completed the remote command transmission and the motor speed drive according to the attitude acquisition data.3.The study of attitude measurement was carried out.A smoothing method combining the sliding mean and Newton interpolation was proposed,and the measurement data were first filtered;using the magnetometer and the accelerometer on the gyroscope data for the complementary filter fusion processing,and the first-order Runge-Kutta method was used to update the attitude data,and finally the attitude data was obtained.4.The control method was studied.In aspect of attitude,a serial PID control algorithm was designed on the basis of angular velocity and angle;as to high hover control,a high-altitude control method with feed forward control and a high-altitude control method with feed forward control were proposed.5.The experimental analytical investigation of the attitude measurement and control method were carried out on the basis of the flight test of the aircraft.Through the flight experiments in pitching,tumbling and yawing conditions,the algorithm of attitude measurement was verified by the waveform reproduction of attitude data.Experiments on attitude control and hover control were also carried out.The results showed that the serial PID had good anti-interference ability,and the proposed hovering control method also possesed good hovering ability.