Although underwater vehicles often operate in time-varying, nonuniform currents, the effect of flow gradients on vehicle dynamics is typically ignored in motion models used for control and estimation. Forces and moments due to a nonuniform flow field are strongest when apparent mass effects are important and flight paths are most sensitive to these disturbances when flow-relative velocities are small – precisely the situation for underwater gliders. This paper presents a nonlinear multi-body dynamic model for an underwater glider operating in an unsteady, nonuniform flow. The eight degree of freedom model incorporates a cylindrically actuated moving mass, a common glider actuation scheme. To illustrate the utility of this full dynamic model, numerical motion predictions are compared with those of simpler models for a variety of nonuniform flow fields. We also demonstrate the use of the full dynamic model for flow estimation using parameter adaptive filtering.

Item Type:	Refereed Article
Keywords:	underwater gliders, multi-body dynamics, nonuniform currents, flow gradient estimation
Research Division:	Engineering
Research Group:	Control engineering, mechatronics and robotics
Research Field:	Field robotics
Objective Division:	Defence
Objective Group:	Defence
Objective Field:	National security
UTAS Author:	Fan, S (Dr Shuangshuang Fan)
ID Code:	125979
Year Published:	2014
Web of Science® Times Cited:	60
Deposited By:	NC Maritime Engineering and Hydrodynamics
Deposited On:	2018-05-17
Last Modified:	2018-10-12
Downloads:	0