Design And Implement Of Autopilot For Quadrotor

The quadrotor aircraft is a four motor-driven, vertical take-off and landing,multi-rotor remote autonomous aircraft, which belongs to a rotary wing unmannedaerial vehicle. Compared with the traditional unmanned aerial vehicles, quadrotoraircraft has strong mobility, small volume and it can change the attitude quickly, italso can be applicable to a variety of harsh environments. Furthermore the mostimportant is the ability to fly in some special restricted environment. So this thesis hasstudied the quadrotor based on ARM and built the aircraft hardware platform toachieve the attitude control of the quadrotor.As the quadrotor aircraft has small size, light weight and low power consumption.This thesis has proposed a digital flight control system. Firstly it has introduced thequadrotor aircraft research status at home and abroad. Secondly it has described thequadrotor aircraft autopilot function and the principles of flight theoretically, analyzedand designed the quad-rotor aircraft hardware, completed the quadrotor system ofhardware selection and circuit design which included the main control module usingARM chip as the main controller, sensor module and the execution module.According to the characteristics of the sensor modules, we need to design adigital filter on the aircraft gyroscopes and accelerators. So we designed severaldigital filters based on the frequency characteristics of the quadrotor aircraft sensordata. And according to the frequency characteristics of the data, we establish theappropriate filter system equations. At the same time, we can build a filter modelbased on MATLAB/SIMULINK. Finally we select a digital filter fit for the quadrotorthrough the simulation results and the amplitude-frequency curve.Quadrotor changed the force of the four-rotor by adjusting the speed of the motor,and changed the flight attitude by change the force. This issue produced a quadrotor,and designed the hardware platform based on ARM. And we proposed a way tocontrol the attitude based on the quaternion approach and the Kalman filter. Anexperiment was introduced to analyze the attitude data carried on quad-rotor. Theexperiment has verified the function and feasibility of the hardware and software and achieved measure the attitude of the quad-rotor accurately.By way of the quadrotor platform designing, it’s possible to achieve thequad-rotor system designed in parallel, reduce the unnecessary weight, improve thereliability of the system, reduce the costs and develop other system based on thequad-rotor platform.