Design And Research Of Navigation Control System For Quadrotors

Quadrotor is a multi-rotor unmanned aircraft, compared to other aircraft which has a simple structure. It has a high mobility in complex environments and requires small take-off and landing space. It is ideally suited to perform reconnaissance and surveillance tasks in the near-surface environment such as indoor and urban environment and more dangerous situation. It is widely used in military and civilian areas, which attracted a great deal of attention and study.The thesis takes the quadrotor as a research object. Firstly analyzing its principles of flight, then combining inertial coordinate system and the body coordinate system to obtain its conversion relationship, and establishing a precise mathematical model aircraft according to Newton’s law and torque balance principle.Secondly, according to the characteristics of the quadrotor, making the hardware selection and design to the main control center of flight control board, motor drive module and power module respectively, in which the main control system is divided into MCU chip, attitude sensor module and wireless communication module, they all have a detailed design description on the board-level, also a practical and reliable hardware experimental platform is build.Thirdly, the aircraft navigation controller is focused as the core of the aircraft. For the problem of how to have a stable flight in a complex environment, an efficient navigation controller is designed for the quadrotor based on the multi-sensor fusion technology. On the basis of the traditional quaternion, a self-compensating method for attitude algorithm is designed. Since attitude angle data collected by the sensors contains noise and error accumulation, an effective filter is designed for multi-sensor data fusion. By comparison, Kalman filter algorithm has a more powerful anti-jamming capability and a better stability compared to the complementary filter. On the question of aircraft control algorithms, synovial variable structure control method is introduced briefly and the PID controller is adopted because it’s more suitable for the quadrotor control in this thesis. Then a dual-loop control method combined the attitude angle and height information is designed and this method is effectively verified.Finally, the design of software systems is introduced and field flight test is made successfully. After the analysis and design for the embedded software processes of the entire control system, debugging and testing the flight combined with the actual aircraft system, also the various flight commissioning procedures and precautions is listed. With analyzing and observing of the attitude angle and other parameters fed back to the PC, the quadrotor finished the flight test and reached the pre-flight effects basically.