Design Of Four-rotor Aircraft With Autonomous Cruise Function

Four-rotor aircraft is a new type of vertical take-off and landing small UAV, which flies in a unique way. The characteristics of four-rotor aircraft is superior to others. Four-rotor aircraft has strong posture holding ability,good mobility and simple structure, which has broad application prospects.This paper presents the hardware design of the overall scheme of four rotor aircraft and selects motor, propeller, electronic governor and power supply. The main controller is based on ATmega2560 microprocessor. The inertial measurement unit is used in MPU6000, which integrates three axis accelerometers and three gyroscopes. The magnetometer module adopts the magnetic heading gauge with high sensitivity HMC5883 L. The barometer module adopts the BMP085 digital high precision pressure sensor. The navigation module is used on company's GPS module ATK-NEO, 6M-V2.3, whose positioning chip uses U-BLOX NEO-6M module. Image transmission module adopts the FPV 5.8G 32 channel 600 MW image transmission module, comprising transmitter module TS835 and receiver module RC832. Voltage alarm module adopts AOK 1-8S power display device. The wireless communication module uses the 3DR Radio Telemetry data transmission module.Then this paper analyzes the basic structure and working principle of the four-rotor aircraft, introduces the methods and steps of modeling. Moreover, The mathematical model of the four-rotor aircraft is established on the basis of the establishment of coordinate system. According to the kinetic model, this paper simulates the motion form of four-rotor aircraft. This paper designs the control circuit of PID controller, analyzes the simulation of the control system, obtains the channel step response curve simulation results. This paper introduces the basic principle of strapdown inertial navigation system and attitude angle derivation, the working principle of GPS navigation system and the navigation solution process. Using EKF, the GPS/INS integrated navigation system is obtained by combining the strapdown inertial navigation and GPS navigation. Experiments show that the integrated navigation can provide navigation function for aircraft.Finally, the paper tests the aircraft outdoors that summarizes the experimental data to verify the performance of attitude keeping, autonomous take-off and landing, autonomous navigation etc. The result shows that the design of the four rotor aircraft and navigation system have the ability of autonomous cruise, and good flight performance.