Real flight demonstration of pitch and roll control for UAV canyon flights

The paper presents results of an experiment prepared to validate the autonomous control of obstacle avoidance designed for a micro UAV to fly in urban canyons. The idea of the obstacle avoidance assumes usage of two miniature laser rangefinders responsi-ble for obstacle detection and range measurement. Measured ranges from obstacles placed on both sides of UAV can be used to simulta-neous control of desired roll and pitch angles. Such combination of controls allows achieving high agility of UAV, because during a maneu-ver of obstacle avoidance UAV can make a turn and climb at the same time. In the experiment, controls of roll and pitch angles were veri-fied separately to ensure high reliability of results and clearance of UAV behavior in the real flight. Because of lack of appropriate objects, which can be used as obstacles, laser rangefinders were directed vertically to the ground instead of the original horizontal configuration. So sensors determine ranges from the ground during a descent flight of UAV, and if their values are lower than defined threshold, it could be interpreted as obstacle detection. The experiment results present UAV behavior adequate to designed controls of roll and pitch angle. The vehicle turns in the opposite direction to the sensing axis of laser rangefinder detecting an obstacle and starts climbing when both sensors detect obstacles at the same range below the threshold