Matthew R. Rossett

Date Approved

11-4-2015

Embargo Period

12-16-2015

Document Type

Thesis

Degree Name

MS Mechanical Engineering

Department

Mechanical Engineering

College

Henry M. Rowan College of Engineering

Advisor

Hong Zhang

Keywords

unmanned aerial vehicles, UAVs, drones

Subject(s)

Drone aircraft

Disciplines

Aeronautical Vehicles

Abstract

Unmanned aerial vehicles, also known as UAVs or drones, are becoming favorable assets in multiple fields. Along with this new technology comes new improvements, including the EHAWK: UAV system, a proposed system to increase the range of UAVs by providing an alternate method for launching. The EHAWK: UAV is a kite based system for launching UAVs. The system uses a kite which acts as a sky anchor or fixed point in the sky. A tether is attached from the kite to the ground. A shuttle device then attached to the tether line. That shuttle carries the UAV up the line and holds it at a predetermined altitude. The shuttle then releases the UAV whenever a command is received and then returns down the line. Releasing the UAV from a shuttle at a higher altitude minimizes onboard energy consumed to bring the UAV to its cruising altitude, effectively increasing its air time and working range.

Multiple kites were investigated to find the ideal one to be use as a sky anchor. It was found that kite stability was a critical factor. The “Flow Form 4.0” kite was chosen and a tether reel system was developed for it. A shuttle was developed, which was attached to the tether via two vertical pulleys. The tether was wrapped around a horizontal motor driven wheel, which allowed the system to transverse the line. The shuttle had a counter weight setup to keep it stable on the line. It also incorporated a release mechanism which held the UAV during climb.

The whole shuttle system was wirelessly controlled by a remote operated by a ground user. The system was tested but found to be an unlikely solution. The issue was found in the concept itself. The EHAWK: UAV was strongly affected by the wind, which is an uncontrollable outside factor. Due to lack of control of the wind speed, wind direction, or change in wind speed, the shuttle encountered disturbances that cause it to flail around on the line. This made safely releasing the UAV difficult. Future research is needed to overcome this issue. Even if this issue was resolved, the whole EHAWK: UAV system is less practical than current conventional methods of launching UAVs for most applications.

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