Embedded Flight Control System Design For Multi-rotor UAV And Experiments

Multi-rotor aircraft has become a hot research topic in the field of UAV because of its own characteristics.The four-rotor aircraft is used more widely.Four-rotor aircraft is symmetrical and has simple structure,excellent low speed flight and hover performance.But,it is often limited by the load and endurance time.The four-rotor aircraft has higher pay load and longer endurance time with variable-pitch and variable-rotational-speed.The paper focuses on the aircraft designing,embedded flight control system verifying and applying for multi-rotor UAV.Firstly,the overall plan of flight control system for variable-pitch and variable-rotational-speed four-rotor aircraft was designed including the design of control law and the requirements of embedded flight control software and hardware.The airborne electronic equipments were identified.The framework and functions of software were identified,too.Embedded flight control system hardware structure was divided into several modules based on the idea of modular design.The architecture of embedded control software and hardware based on ATMEGA2560-16 AU has been given.The hardware modules of power conversion,data communication and other related peripherals were designed.Then,the flight control law was designed using PID controller based on the flight dynamics model of the aircraft.The control law design and simulation of flight control system was completed for each channel and each control loop base on the idea of step by step optimization design.The control effect was optimized with the integral-separation and anti-saturation method.The simulation results showed that the designed control law can meet the requirement of flight control performance.The automatic tuning of flight control parameters was realized with Particle Swarm Optimization and it was verified by simulation.Finally,the reliability of the control law and flight dynamics model was further verified by three dimensional real-time visual simulation platform.The four-rotor aircraft flight test was finished successfully and the results of flight test showed that the embedded flight control system is feasible and reliable.