The Virginia Center for Autonomous Systems (VaCAS) is an ICTAS/College of Engineering research center which facilitates interdisciplinary research in autonomous systems technology. VaCAS hosts research activities spanning every application domain: water, land, air, and space. VaCAS member research activities range from fundamental control theory to vehicle development to applications for science, security, and commerce.


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Recent Submissions

  • User Manual for Bioflyer Database 

    Allen, David (2015-11-30)
    In order to compare the results of the new integrated morphology and gait optimization to diverse examples from biology, a comprehensive and easily accessible database is required. Unfortunately, no such database is publicly ...
  • Under-actuated Controllability for Spacecraft Rendezvous 

    Rogers, Andrew; Woolsey, Craig A.; McGwier, Robert W. (Virginia Tech, 2014-06-27)
    In this report, we examine the controllability of a particular form of the equations of motion for spacecraft formation flying. These equations, the Tschauner-Hempel equations, rescale the formation flying equations to a ...
  • Design and testing of a pneumatically propelled underwater glider for shallow water 

    Wolek, Artur; Gode, Tejaswi; Woolsey, Craig A.; Quenzer, Jake; Morgansen, Kristi A. (Virginia Center for Autonomous Systems, 2015-10-28)
    This report details the design and testing of a pneumatically propelled underwater glider. The vehicle was designed as a platform for motion control experimentation, and to explore the use of novel actuator designs to ...
  • Exploration of under-ice regions with ocean profiling agents (EUROPA) 

    Allen, David W.; Jones, Matthew; McCue-Weil, Leigh S.; Woolsey, Craig A.; Moore, William B. (Virginia Center for Autonomous Systems, 2013-09-14)
    Europa is an incredibly enticing target for exploration – the nearest reaches of what may be a vast new "habitable zone" of interior oceans warmed and stirred by tidal forces. Decades of NASA and National Academy studies ...
  • Vehicle Dynamics in Currents 

    Woolsey, Craig A. (Virginia Center for Autonomous Systems, 2011)
    Vehicles operating in non-uniform flow fields are subject to forces and moments that are not captured by kinematic motion models. These effects are even greater when the mass of the displaced fluid is commensurate with the ...
  • Optimal Control of an Undersea Glider in a Symmetric Pull-up 

    Kraus, R.; Cliff, Eugene M.; Woolsey, Craig A.; Luby, J. (Virginia Center for Autonomous Systems, 2008)
    An undersea glider is a winged autonomous undersea vehicle which modulates its buoyancy to rise or sink and moves its center of mass to control pitch and roll attitude. By properly phasing buoyancy and pitch control, an ...
  • Control-Oriented Planar Motion Modeling of Unmanned Surface Vehicles 

    Sonnenburg, C.; Gadre, Aditya; Horner, D.; Krageland, S.; Marcus, A.; Stilwell, Daniel J.; Woolsey, Craig A. (Virginia Center for Autonomous Systems, 2010)
    This technical report describes a comparison of experimentally identified dynamic models for the planar motion of an unmanned surface vehicle (USV). The objective is to determine a model which is (1) sufficiently rich to ...
  • Dynamics & Control of Underwater Gliders II: Motion Planning and Control 

    Mahmoudian, N.; Woolsey, Craig A. (Virginia Center for Autonomous Systems, 2010)
    This paper describes an underwater glider motion control system intended to enhance locomotive efficiency by reducing the energy expended by vehicle guidance and control. In previous work, the authors derived an approximate ...
  • Nonlinear Estimation with State-Dependent Gaussian Observation Noise 

    Spinello, D.; Stilwell, Daniel J. (Virginia Center for Autonomous Systems, 2008)
    We consider the problem of estimating the state of a system when measurement noise is a function of the system's state. We propose generalizations of the iterated extended Kalman filter and of the extended Kalman filter ...
  • Sensor Error Model for a Uniform Linear Array 

    Gadre, Aditya; Roan, Michael J.; Stilwell, Daniel J. (Virginia Center for Autonomous Systems, 2008)
    We derive a measurement error model for a uniform linear array whose output is the bearing to a single narrowband acoustic source. The measurement error depends on various array as well as environmental parameters, which ...
  • Dynamics and Control of Underwater Gliders I: Steady Motions 

    Mahmoudian, N.; Geisbert, J.; Woolsey, Craig A. (Virginia Center for Autonomous Systems, 2007)
    This paper describes analysis of steady motions for underwater gliders, a type of highly efficient underwater vehicle which uses gravity for propulsion. Underwater gliders are winged underwater vehicles which locomote by ...