Frederick R Stahr

20120318188, Dec 20, 2012

Sep 24, 2010

12/890584

Edison Thurman Hudson - Chapel Hill NC, US
Robert Eugene Hughes - Chapel Hill NC, US
Timothy James Osse - La Spezia, IT
Frederick Roland Stahr - Seattle WA, US
Jason Isaac Gobat - Burien WA, US

B63G 8/22

114333

Multi-stage buoyancy changing system for an autonomous underwater vehicle comprises: an internal reservoir configured to hold a fluid; an external bladder connected to the internal reservoir and configured to exchange fluid with the internal reservoir via one or more channels; a first device configured to move fluid through a channel from the internal reservoir to the external bladder at an optimized efficiency for an ambient pressure of a first segment of a dive profile to increase apparent displacement and buoyancy of the vehicle; and a second device configured to move fluid through a channel from the internal reservoir to the external bladder at an optimized efficiency for an ambient pressure of a second segment of the dive profile to increase an apparent displacement and a buoyancy of the vehicle. The first segment of the dive profile includes a different ambient pressure range than the second segment of the dive profile.

20130239870, Sep 19, 2013

May 9, 2013

13/890939

Robert Eugene Hughes - Chapel Hill NC, US
Frederick Roland Stahr - Seattle WA, US
Jason Isaac Gobat - Burien WA, US
Timothy James Osse - Sarzana, IT

iRobot Corporation - Bedford MA

B63G 8/22

114333

A multiple stage buoyancy changing system, or variable buoyancy device, for an underwater vehicle. The multiple stage buoyancy changing system comprises: a pressure hull containing a flexibly-sized internal fluid reservoir; a flexibly-sized external fluid reservoir attached to the pressure hull and connected to the internal reservoir; a system of devices and channels configured to move fluid between the internal fluid reservoir and the external fluid reservoir to change a displaced volume of the vehicle. Each stage of the variable buoyancy device can be optimized for maximum energy efficiency while changing the vehicle's displaced volume within an ambient pressure range. A control system for the variable buoyancy device engages different stages depending on ambient external pressure such that maximum energy efficiency is achieved over a large range of pressures/depths.

20110297071, Dec 8, 2011

Mar 1, 2011

13/038373

Edison Thurman Hudson - Chapel Hill NC, US
Robert Eugene Hughes - Chapel Hill NC, US
Frederick Roland Stahr - Seattle WA, US
Jason Isaac Gobat - Burien WA, US
Timothy James Osse - La Spezia, IT

B63G 8/14
B63G 8/22

114331

A multiple stage buoyancy changing system, or variable buoyancy device, for an underwater vehicle. The multiple stage buoyancy changing system comprises: a pressure hull containing a flexibly-sized internal fluid reservoir; a flexibly-sized external fluid reservoir attached to the pressure hull and connected to the internal reservoir; a system of devices and channels configured to move fluid between the internal fluid reservoir and the external fluid reservoir to change a displaced volume of the vehicle. Each stage of the variable buoyancy device can be optimized for maximum energy efficiency while changing the vehicle's displaced volume within an ambient pressure range. A control system for the variable buoyancy device engages different stages depending on ambient external pressure such that maximum energy efficiency is achieved over a large range of pressures/depths.