# US 2021/0276679 A1 · Passive Ballast Device, System and Methods of Using Same

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- Number: US 2021/0276679 A1
- Document ID: US20210276679A1
- Status: Published application
- Kind: A1
- Application number: 16/812,834
- Filed: 2020-03-09
- Published: 2021-09-09
- Earliest claimed: 2017-10-16
- Assignees: Woods Hole Oceanographic Institution
- Applicants: Woods Hole Oceanographic Institution
- Inventors: Jeffrey Kaeli; Robin Littlefield
- Web page: https://patentgrep.com/patent/US20210276679A1

## CPC

- B63G 8/22: Adjustment of buoyancy by water ballasting; Emptying equipment for ballast tanks ({conduits for emptying or ballasting on vessels in general B63B13/00;} stabilising vessels using ballast tanks B63B43/06)
- B63G 8/24: Automatic depth adjustment; Safety equipment for increasing buoyancy, e.g. detachable ballast, floating bodies
- B63G 8/39: Arrangements of sonic watch equipment, e.g. low-frequency, sonar
- G05D 1/0016: {characterised by the operator's input device (input arrangements for computing systems in general G06F3/00)}
- G05D 1/0022: {characterised by the communication link (data switching networks in general H04L12/00)}
- G05D 1/048: {specially adapted for water vehicles}
- G05D 1/0692: {specially adapted for under-water vehicles}
- B63G 2008/004: {autonomously operating}
- B63G 2008/005: {remotely controlled}
- B63G: OFFENSIVE OR DEFENSIVE ARRANGEMENTS ON VESSELS; MINE-LAYING; MINE-SWEEPING; SUBMARINES; AIRCRAFT CARRIERS (means of attack or defence in general, e.g. turrets F41H)
- G05D: SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES

## Abstract

A passive ballast device, system and method of using same, configured for use with a submersible vehicle in a liquid environment, including a chamber having at least one rigid wall to define at least a portion of a chamber volume, and a passively movable compensator having at least first and second surfaces, the first surface configured to be exposed to the liquid environment, the second surface excluded from the liquid environment, and forming, together with the at least one wall of the chamber, a fluid-tight seal to establish the remainder of the chamber volume, to exclude the liquid environment from the chamber volume and configured to adjust the chamber volume to at least a first chamber volume and a second chamber volume. The chamber volume is configured to establish at least a first buoyancy and second buoyancy, the compensator is configured to respond to a change in environmental pressure within the liquid environment, and the compensator is passively moved by the change in environmental pressure to change the first chamber volume to the second chamber volume, thereby changing from the first buoyancy to the second buoyancy.

## Claims

### Claim 1

A passive ballast device, configured for use with a submersible vehicle in a liquid environment, comprising:
a chamber having at least one rigid wall to define at least a portion of a chamber volume;
a passively movable compensator having at least first and second surfaces, the first surface configured to be exposed to the liquid environment, the second surface excluded from the liquid environment, and forming, together with the at least one rigid wall of the chamber, a fluid-tight seal to establish a remainder portion of the chamber volume, to exclude the liquid environment from the chamber volume and configured to adjust the chamber volume to at least a first chamber volume and a second chamber volume;
wherein the chamber volume is configured to establish at least a first buoyancy and a second buoyancy;
wherein the compensator is configured to respond to a change in environmental pressure within the liquid environment.

### Claim 2 (depends on 1)

The device of claim 1 wherein the chamber and the compensator are carried within a housing that is configured to be exposed to the liquid environment.

### Claim 3 (depends on 1)

The device of claim 1 further comprising at least one retaining mechanism and a compressible working medium filling the chamber volume, wherein the at least one retaining mechanism is located within the chamber volume, dividing the chamber volume into a fixed section and a variable section, wherein the compensator is configured to be constrained to the variable section between a first compensator position and a second compensator position by the at least one retaining mechanism.

### Claim at position 4

4-6. (canceled)

### Claim 7 (depends on 1)

The device of claim 1 wherein the compensator experiences resistive forces that increases during increased environmental pressure.

### Claim 8

(canceled)

### Claim 9 (depends on 2)

The device of claim 2 further comprising:
a controllable opening having at least a first state and a second state, and forming a second space between the compensator and the controllable opening; and
a controller;
wherein the controllable opening separates the compensator and the second space from the liquid environment when placed in the second state;
wherein the first state provides at least a partial opening between the liquid environment and second space, and the second state provides a fluid-tight seal between the liquid environment and second space;
wherein the controller is configured to change between the at least first and second states of the controllable opening.

### Claim 10

(canceled)

### Claim 11 (depends on 9)

The device of claim 9 further comprising an external reservoir filled with a fluid and connected to the controllable opening, wherein the fluid is in fluid contact with the compensator, and the external reservoir forms a seal along with the controllable opening, excluding the liquid environment from the controllable opening.

### Claim at position 10

12-22. (canceled)

### Claim 23

A device for single transponder relative navigation, comprising:
a mapping sensor configured to interrogate a transponder;
a propulsion system;
a controller connected to said mapping sensor and configured to calculate the device's position relative to a transponder in polar R-θ coordinates.

### Claim 24 (depends on 23)

The device of claim 23 wherein said mapping sensor directly measures the radial range between said mapping sensor and a transponder.

### Claim 25 (depends on 23)

The device of claim 23 further comprising a releasable package comprising a transponder and said releasable package is deployable from the device.

### Claim 26 (depends on 25)

The device of claim 25 further comprising a releasable buoyant data module, wherein said buoyant data module is configured to relay mission information to operators by satellite.

### Claim 27 (depends on 25)

The device of claim 25 wherein said releasable package further comprises a floatation device, a mooring, and a mooring line, said mooring line connecting said floatation device to said transponder and said transponder to said mooring.

### Claim 28 (depends on 27)

The device of claim 27 wherein the device is configured to home in on said transponder and dock to said mooring line.

### Claim 29

A method of relative navigation, comprising the steps of:
(a) selecting a vehicle and placing it in a liquid environment;
(b) deploying a transponder in said liquid environment, wherein said transponder is interrogatable by said vehicle;
(c) moving said vehicle relative to said transponder;
(d) optimizing the device's position estimation and areal coverage rate by establishing the radial range between said vehicle and said transponder and computing in polar R-θ coordinates the device's position relative to said transponder.

### Claim 30 (depends on 29)

The method of claim 29, wherein said vehicle comprises a mapping sensor and said mapping sensor directly measures the radial range between said vehicle and said transponder.

### Claim 31 (depends on 29)

The method of claim 29 wherein said vehicle further comprises a single channel sonar configured to produce sonar scans, and further comprising the step of (l) providing full coverage with sonar scans while executing step (c).

### Claim 32 (depends on 29)

The method of claim 29, wherein said vehicle further comprising a releasable package comprising said transponder, said releasable package is deployable from said vehicle, and said vehicle deploys said releasable package in step (b).

### Claim 33 (depends on 32)

The method of claim 32 wherein said vehicle further comprises a releasable buoyant data module, and the step of (g) relaying mission information from said vehicle to said buoyant data module and to operators by satellite.

### Claim 34 (depends on 32)

The method of claim 32 wherein said releasable package further comprises a floatation device, a mooring, and a mooring line, said mooring line connecting said floatation device to said transponder and said transponder to said mooring.

### Claim 35 (depends on 34)

The method of claim 34 further comprising the steps (e) homing said vehicle to said transponder and (f) docking said vehicle to said mooring line.

### Claim 36 (depends on 29)

The method of claim 29 further comprising the steps of (h) obtaining orthogonal bearing between said vehicle and said transponder and (i) constraining the navigational uncertainty of said vehicle with said orthogonal bearing.

### Claim 37 (depends on 36)

The method of claim 36 further comprising the steps of (j) setting a threshold of the radial range R, and (k) turning inward when the radial range exceeds said threshold or turning outward when the radial range is less than said threshold.