Design of four-rotor autonomous target-dropping aircraft based on image processing

Abstract

The aim of this study is to design and produce a quad-rotor autonomous target shooting aircraft based on STM32F407 microprocessor and OV7725 image acquisition system. Herein, the quaternion is defined by using Euler’s theorem, navigation coordinate system and carrier coordinate system. Taking STM32F407 master controller as the core, the control system of the aircraft is composed of, distance measuring and height setting module, six-axis motion sensor measurement module, three-axis magnetometer measurement module and camera unit trajectory tracking module. Then, four circuits of the flight control system were designed, including the main control circuit, attitude measurement circuit, throwing rake control circuit and image processing circuit. In addition, three algorithms related to aircraft were prepared, including attitude control cascade PID algorithm, height control algorithm and attitude solution algorithm, and an image processing software was designed. On this basis, the aircraft was built, and finally its flight attitude, height, fixed point, and hover were tested. The results showed that all the algorithms are correct, and the aircraft can successfully pitch, roll, yaw, recognize image trajectory, and automatically drop materials and cruise.