System Design And Autonomous Mission Planning For Small Multi-rotor Aircraft

With the advantages of simple structure and flexible control, multi-rotor aircraft driven by Blushless DC Motor has great research value and broad application prospects. With the rapid development of UAV technology, autonomous control and mission planning based on small multi rotor aircraft will become the main direction of the future research.In this paper, the attitude control principle of the hexa-rotor aircraft as the representative is carefully analyzed. According to the requirements of the project a hexa-rotor designs with the advantages of heavy loads, easy to carry, good stability and easy to develop has been calibrated and debugged. At the same time, in order to realize the environment perception, a set of airborne environment sensing system is designed. Then because of the limitation of battery and load the power module is designed independently. In addition, taking into account the attitude change and jitter of the aircraft will affect the environmental perception system, the inertial measurement module and the visual range meter are installed for orientation calibration. Finally, the construction of 3D scene is realized.Based on the completion of hexa-rotor aircraft system design, the feasibility analysis of the autonomous mission planning is carried out. Aiming at the characteristics of MAVLink communication protocol and ROS, the bridge of MAVLink-ROS was built and the communication between aircraft and ROS is realized. After analyzing the mission of planning constraints and design scheme, the autonomous mission planning framework and control flow chart are present. In order to ensure the reliability and security, we put forward a kind of simulation test method and improve the method. Then the connection between SITL and ROS is extended and the feasibility of the aircraft with ROS communication is verified.In order to ensure the hexa-rotor has better flight characteristics, we need to retune the PID control parameters. After completing the parameters adjustment, the stability and sensitivity of hexa-rotor has been increased. At the same time, in order to avoid the loss caused by the error of the autonomous mission planning, we design many different experiments about autonomous mission planning to verify the validity and reliability.