Design And Implementation Of Attitude Control System For A Quadrotor UAV

Quadrotor UAV driven by Blushless DC Motor have four airscrew symmetric distributed, it has simple structure and flexible control. It has a broad application prospect in civil, police, military and scientific research.The nonlinear and under-actuated feature of Quadrotor UAV is difficulty in control. This paper studies the attitude control problem for a Quadrotor UAV.Establishing mathmaticl model according toNewton’s second low and Euler equation, and simplify the model basing on the attitude control problem. Represent the rotation of Quadrotor UAV using quaternion, and fuse the sener measurement by a attitude Measuring algorithm. According to the simplifyed model of Quadrotor UAV, dispatch the attitude to three separate control angel, and design a Cascade PID Controller for each angle. Innor loop of the Cascade PID Controller is angle rate Controller, the outer is angle control loop. The simulation results show the feasibility of the proposed algorithm.A novel system design of Quadrotor is presented to solve the attitude control problem for a Quardrotor UAV. The novel design divided the system to three modules:attitude detection stability control and actuator. Referencing to the main Quadrotor open source projects around the world, chose sensors, design the circuit Schematic and makes PCB, write and debug code. Using independent attitude detection module and control module, system has240Hz control frequency, testing results show the good working performance of each unit witch guarantee the real-time performance.A independent development friendly interface is designed for on-line debug demand. A fight control experiment is performed on SmartQT Quadrotor, the experiment results implemented on a self-designed Quardrotor aircraft (SmartQT) show the validity of the proposed attitude control algorithm.