Real Flight Demonstration of Pitch and Roll Control for Uav Canyon Flights

Abstract

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 responsible for obstacle detection and range measurement. Measured ranges from obstacles placed on both sides of UAV can be used to simultaneous control of desired roll and pitch angles. Such combination of controls allows achieving high agility of UAV, because during a maneuver of obstacle avoidance UAV can make a turn and climb at the same time. In the experiment, controls of roll and pitch angles were verified 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.

Autonomous Flight in the Canyons of Streets on the Basis of Information Derived from the Vision System

“…In order to determine lines location in relation to checkpoint "A", points B R , B L , D R and D L need to be located as well as the following distances according to Eq. 1 [7]. The length of segments with index p are formulated in pixels and those without p are formulated in meters.…”

“…Therefore, logic module should have access to φ PIDleft and φ PIDright outputs of both PID controllers, d L , d R distances from obstacles as well as φ autopilot desired roll angle from navigation. Scheme of logic module operation is described in detail in [7].…”

Influence Environment and Parameters Ablative Laser Texturing on Selected Properties Surface Layer Steel 100CrMnSi6-4

“…Recently, these bearings have substituted other technological solutions. Massive roll bearing with the greatest size are frequently applied in machines working in open pit mines [1,2]. Their cost is up to few percent of the new machine, however their malfunction generates much greater costs, linked to the long-time machines demurrage.…”

“…Durability of such bearings is limited due to losses of the basic geometrical parameters. The phenomenon of the deformation wear, in opposite to the fatigue mechanisms, has less rapid nature, what makes it predictable, if the load distribution and materials characterizations are known [1]. High carbon content chromium steel is applied for fabrication of bearings ring and rolling elements.…”