Abstract:
The Sentry AUV represents a radical departure from conventional AUV design, particularly
with respect to actuation. The vehicle's combined foil/thruster actuators
have the potential to produce a vehicle both maneuverable in the veritical plane and
efficient in forward flight, well suited to survey work over rough topography. Capitalizing
on this; however, requires an understanding of the vehicles dynamics.
In this work, we present the development and analysis of an analytic model of
the Sentry AUV. Our goals were to develop a model sufficiently accurate in terms of
the mission profile to identify critical vehicle behaviors influencing successful mission
completion. The analytical vehicle model was developed with structural accuracy
in mind, and under the requirement that it handle a large range of vertical plane
velocities,
Our primary methodology for analysis was through the design of a linear controller,
whose behavior was investigated in simulation and as implemented on a 1/4-scale
physical model. Based on decoupled linearized models for near-horizontal flight
derived from the full non-linear model, classical linear controllers were designed and
validated by simulation and implementation on the physical model. Closed loop simulations
conducted at high angle of attack verified the vehicle's predicted maneuverability
in the vertical plane. Ultimately we determined the vehicle's input structure
limited the achievable performance of a classical linear controller.
