Graduation Year


Document Type




Degree Granting Department

Mechanical Engineering

Major Professor

Stuart Wilkinson, Ph.D.

Committee Member

Craig Lusk, Ph.D.

Committee Member

Kyle Reed, Ph.D.


Amphibious, Submarine, Robot, Trafficability, Dynamics


Double-screw vehicles have been developed to operate in soft, wet terrains such as marsh, snow, and water. Their exceptional performance in soft and wet terrains is at the expense of performance on rigid terrains such as pavement. Furthermore, turning can be difficult because the method of turning varies depending on the terrain. Therefore, in this study, several different quad-screw-configurations were proposed and tested to improve upon double-screw vehicles.

A test-bed was developed which could easily be converted into each quad-screw-configuration for testing on a variety of surfaces (grass, dirt, sand, clay, marsh, snow, gravel, pavement, and water). In addition, a force-vector analysis was performed for each screw-configuration to predict and understand performance in different terrains.

From the testing and analysis, the inline-screw configuration was the most versatile because it was omnidirectional on all surfaces but water and pavement. Regardless, it was fully capable of navigating water, both on the surface and submerged, and pavement by rotating about its center.