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Full-Text Articles in Engineering
Obstacle Avoidance For Small Unmanned Air Vehicles, Brandon R. Call
Obstacle Avoidance For Small Unmanned Air Vehicles, Brandon R. Call
Theses and Dissertations
Small UAVs are used for low altitude surveillance flights where unknown obstacles can be encountered. These UAVs can be given the capability to navigate in uncertain environments if obstacles are identified. This research presents an obstacle avoidance system for small UAVs. First, a mission waypoint path is created that avoids all known obstacles using a genetic algorithm. Then, while the UAV is in flight, obstacles are detected using a forward looking, onboard camera. Image features are found using the Harris Corner Detector and tracked through multiple video frames which provides three dimensional localization of the features. A sparse three dimensional …
Flight Testing Small, Electric Powered Unmanned Aerial Vehicles, Jon N. Ostler
Flight Testing Small, Electric Powered Unmanned Aerial Vehicles, Jon N. Ostler
Theses and Dissertations
Flight testing methods are developed to find the drag polar for small UAVs powered by electric motors with fixed-pitch propellers. Wind tunnel testing was used to characterize the propeller-motor efficiency. The drag polar was constructed using data from flight tests. The proposed methods were implemented for a small UAV. A drag polar was found for this aircraft with CDo equal to 0.021, K1 equal to 0.229, and K2 equal to -0.056. This drag polar was then used to find the following performance parameters; maximum velocity, minimum velocity, velocity for maximum range, velocity for maximum endurance, maximum rate of climb, maximum …
Remote Terrain Navigation For Unmanned Air Vehicles, Stephen R. Griffiths
Remote Terrain Navigation For Unmanned Air Vehicles, Stephen R. Griffiths
Theses and Dissertations
There are many applications for which small unmanned aerial vehicles (SUAVs) are well suited, including surveillance, reconnaissance, search and rescue, convoy support, and short-range low-altitude perimeter patrol missions. As technologies for microcontrollers and small sensors have improved, so have the capabilities of SUAVs. These improvements in SUAV performance increase the possibility for hazardous missions through mountainous and urban terrain in the successful completion of many of these missions. The focus of this research was on remote terrain navigation and the issues faced when dealing with limited onboard processing and limited payload and power capabilities. Additional challenges associated with canyon and …