Autonomous Hovering Control for a Quadrotor Unmanned Aerial Vehicle

In this paper, an autopilot system for the quadrotor unmanned aerial vehicle (UAV) is developed by utilizing a digital signal processor (DSP) as the on-board micro-control unit (MCU). The hardware setup and the software are also developed for the autonomous flight control of the UAV. The main design procedure includes the controller board design, brushless DC motor driver design, sensor data processing software design, and flight control algorithm design. The control algorithm is developed based on the inner loop and outer loop control method. Proportional Derivative (PD) controllers are proposed for the attitude dynamics (inner loop) and position dynamics (outer loop) respectively. Autonomous hovering control is achieved via the control of roll angle, pitch angle, yaw angle and altitude of the UAV. Experiments results are included to demonstrate the hovering control performance.