Design And Implemention Of Quadtotor System Based On Data Fusion

As a new type of UAV,the quadrotor has the characteristics of small size,high flexibility,simple structure,and low price.It has broad application prospects in the civilian and military fields.Since its invention,the quadrotor has attracted a great of interest from the world,and as a controlled object,the quadrotor is a complex system with underactuation and strong coupling,which has great difficulty in control.Aiming at the structural characteristics of the quadrotor,this paper presents a design scheme and verifies the effectiveness of the scheme through computer simulation and actual flight test.The research focuses of this paper are:(1)The establishment of mathematical model of quadrotor.Firstly,according to the flight principle of the aircraft,the geographic coordinate system and the body coordinate system are selected as the reference coordinate system of the aircraft.The Euler angle of the aircraft is deduced by the quaternion method.Finally,according to aerodynamics and rigid body kinematics,the dynamic equations and torque balance equations of the quadrotor are deduced.(2)The quadrotor aircraft attitude algorithm.Aiming at the problem that the relative attitude error of the rotorcraft is relatively large in high-mobility and complex flight environment,the flight attitude calculation based on multi-sensor information fusion method is proposed.Firstly,a Kalman filter has been designed to compensate the noise of gyroscpope and obtain a more precise angularrate.Then,fuse the new angularrate with information of accelerometer and magnetometer to count quaternion,which can work out quadrotor's attitude in accordance with the conversion relation of quaternion and attitude rotation matrix.(3)Hardware selection and design.The design ideas of hardware components of the aircraft are discussed in detail.The STM32F103C8T6 is used as the main control chip of the aircraft,and the chopper circuit is used to convert the power supply voltage.In order to reduce the working noise of the aircraft and ensure the service life of the system,a permanent magnet brushless DC motor is used as a stimulus unit of the aircraft,and a position sensorless control algorithm is adopted to drive the motor.(4)The design of attitude and position controller.On the premise of establishing the mathematical model of the quadrotor,the attitude PID controller is designed.Based on the controller,the fuzzy control algorithm is combined to make the attitude controller adapt to the change of the aircraft system parameters and the adaptive attitude controller is realized.A position PD controller was designed to enable the aircraft to track the set route.Finally,the correctness of the controller was verified by actual flight test.