U.S. patent application number 14/210152 was filed with the patent office on 2014-09-18 for systems and methods for improved pressure vessels.
This patent application is currently assigned to HADAL, INC.. The applicant listed for this patent is HADAL, INC.. Invention is credited to Robert S. Damus, Dylan Owens, Richard J. Rikoski.
Application Number | 20140259618 14/210152 |
Document ID | / |
Family ID | 50555284 |
Filed Date | 2014-09-18 |
United States Patent
Application |
20140259618 |
Kind Code |
A1 |
Damus; Robert S. ; et
al. |
September 18, 2014 |
SYSTEMS AND METHODS FOR IMPROVED PRESSURE VESSELS
Abstract
Systems and methods are described herein for manufacturing a
pressure vessel component. The pressure vessel component may be
made from a metal that is cast to produce a gross pressure vessel
component. Casting the metal may comprise sintering the metal
followed by a hot isostatic press (HIP) process. In other
embodiments, casting the metal may comprise pouring molten metal
into a mold. Portions of the gross pressure vessel component may
have an increased thickness located at predetermined positions on
the gross pressure vessel component. These portions may include
bosses or other designed features intended for the finalized
pressure vessel component. The gross pressure vessel may be indexed
to select the portions, and these selected portions may then be
machined to produce the final pressure vessel component.
Inventors: |
Damus; Robert S.; (Alameda,
CA) ; Owens; Dylan; (San Jose, CA) ; Rikoski;
Richard J.; (Alameda, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
HADAL, INC. |
OAKLAND |
CA |
US |
|
|
Assignee: |
HADAL, INC.
Oakland
CA
|
Family ID: |
50555284 |
Appl. No.: |
14/210152 |
Filed: |
March 13, 2014 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61792708 |
Mar 15, 2013 |
|
|
|
Current U.S.
Class: |
29/463 ;
29/527.6; 29/56.5 |
Current CPC
Class: |
G01S 15/02 20130101;
Y10T 29/49117 20150115; H01M 2/024 20130101; B63B 2027/165
20130101; Y10T 29/49826 20150115; B63G 8/39 20130101; B63B 2035/405
20130101; Y10T 29/49989 20150115; F17C 1/00 20130101; B64C 2201/205
20130101; H01M 10/052 20130101; Y10T 29/5176 20150115; Y10T
428/1376 20150115; G01S 15/107 20130101; H01M 2/025 20130101; G01S
15/104 20130101; G01S 15/8904 20130101; B22D 31/00 20130101; G01S
15/60 20130101; G01S 7/52004 20130101; G01S 15/588 20130101; Y02E
60/10 20130101; H01M 10/4257 20130101; B63G 2008/004 20130101; B63G
2008/008 20130101; Y10T 29/49893 20150115; B63B 35/40 20130101;
B63B 27/16 20130101; B63B 27/36 20130101; Y10T 428/1352 20150115;
B63G 8/00 20130101; B63G 8/001 20130101; B29C 44/3415 20130101;
B63B 3/13 20130101 |
Class at
Publication: |
29/463 ;
29/527.6; 29/56.5 |
International
Class: |
B22D 31/00 20060101
B22D031/00; F17C 1/00 20060101 F17C001/00 |
Claims
1. A method of manufacturing a pressure vessel component,
comprising: casting a metal to produce a gross pressure vessel
component, wherein casting includes forming portions of the gross
pressure vessel component having an increased thickness and being
located at predetermined positions on the gross pressure vessel
component; indexing the gross pressure vessel component to select
the portions of the gross pressure vessel component for machining;
and machining the gross pressure vessel component to produce a
pressure vessel component, including machining the selected
portions.
2. The method of claim 1, wherein the pressure vessel component is
one of: a hemisphere, a cylinder, an ellipsoid, a cube, a
rectangular prism, or a square endcap for a cylindrical pressure
vessel.
3. The method of claim 1, wherein the metal is titanium.
4. The method of claim 1, wherein casting the metal to produce a
gross pressure vessel component comprises sintering the metal
followed by a hot isostatic press (HIP) process.
5. The method of claim 1, wherein casting the metal to produce a
gross pressure vessel component comprises pouring molten metal into
a mold.
6. The method of claim 1 further comprising heat treating the
pressure vessel component.
7. The method of claim 1, wherein the pressure vessel component is
designed to mate with a second pressure vessel component.
8. The method of claim 7, wherein a hinge is used to open, close,
and align the pressure vessel component with the second pressure
vessel component.
9. The method of claim 7, further comprising: mating the pressure
vessel component with the second pressure vessel component; and
forming at least a partial vacuum in a cavity formed by the
pressure vessel component and the second pressure vessel
component.
10. The method of claim 1, wherein the portions having the
increased thickness occur at predetermined angles of elevation and
azimuth relative to a sphere equatorial plane.
11. The method of claim 1, wherein machining the gross pressure
vessel component comprises machining cable pass-throughs at the
portions having the increased thickness.
12. The method of claim 1, wherein the predetermined locations of
the portions of the gross pressure vessel component having an
increased thickness are based on a plurality of possible
arrangements of components within the gross pressure vessel.
13. The method of claim 12, wherein the selected portions of the
gross pressure is a subset of the portions of the gross pressure
vessel component having an increased thickness.
14. The method of claim 13, wherein the subset is determined based
on one of the plurality of possible arrangements of the components
within the gross pressure vessel.
15. The method of claim 14, comprising machining the selected
portions after casting and indexing the gross pressure vessel.
16. A system for manufacturing a pressure vessel component,
comprising: a mold for casting a metal to produce a gross pressure
vessel component, wherein casting includes forming portions of the
gross pressure vessel component having an increased thickness and
being located at predetermined positions on the gross pressure
vessel component; and machining equipment configured to: index the
gross pressure vessel component to select the portions of the gross
pressure vessel component for machining; and machine the gross
pressure vessel component to produce a pressure vessel component,
including machining the selected portions.
17. The system of claim 16, wherein the pressure vessel component
is one of: a hemisphere, a cylinder, a cube, or a rectangular
prism.
18. The system of claim 16, wherein the metal is titanium.
19. The system of claim 16, wherein casting the metal to produce a
gross pressure vessel component comprises sintering the metal
followed by a hot isostatic press (HIP) process.
20. The system of claim 16, wherein casting the metal to produce a
gross pressure vessel component comprises pouring molten metal into
the mold.
21. The system of claim 16, wherein the machining equipment is
further configured to heat treat the pressure vessel component.
22. The system of claim 16, wherein the pressure vessel component
is designed to mate with a second pressure vessel component.
23. The system of claim 22, wherein a hinge is used to open, close,
and align the pressure vessel component with the second pressure
vessel component.
24. The system of claim 22, wherein the pressure vessel component
and the second pressure vessel component are configured to form at
least a partial vacuum in a cavity formed by the pressure vessel
component and the second pressure vessel component.
25. The system of claim 16, wherein the portions having the
increased thickness occur at predetermined angles of elevation and
azimuth relative to a sphere equatorial plane.
26. The system of claim 16, wherein the machining equipment is
configured to machine the gross pressure vessel component by
machining cable pass-throughs at the portions having the increased
thickness.
27. The system of claim 16, wherein the predetermined locations of
the portions of the gross pressure vessel component having an
increased thickness are based on a plurality of possible
arrangements of components within the gross pressure vessel.
28. The system of claim 27, the selected portions of the gross
pressure is a subset of the portions of the gross pressure vessel
component having an increased thickness.
29. The system of claim 28, wherein the subset is determined based
on one of the plurality of possible arrangements of the components
within the gross pressure vessel.
30. The system of claim 29, comprising machining the selected
portions after casting and indexing the gross pressure vessel.
31. The system of claim 16, wherein the pressure vessel component
includes a radiator for heat exchange.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional
Application Ser. No. 61/792,708, filed Mar. 15, 2013, the contents
of which is incorporated by reference herein in its entirety.
BACKGROUND
[0002] The past several decades have seen a steady increase in the
number of unmanned underwater robotic systems deployed for use in
the ocean. These underwater systems often use pressure vessels that
are configured to maintain an internal pressure and resist the high
pressures at ocean depths. Typical methods for manufacturing
pressure vessels often involve casting, forging, or machining
titanium or a similar metal into the final shape of the pressure
vessel. However, the pressure vessels may have bosses or other
design protrusions that require custom casts or molds. Such custom
designs may drive up the cost of manufacture, especially for larger
pressure vessel designed for manned missions. As such, a need
exists for a low cost method of manufacturing custom pressure
vessel components.
SUMMARY
[0003] Systems and methods are described herein for manufacturing a
pressure vessel component. According to one aspect, a method of
manufacturing a pressure vessel component may comprise casting a
metal to produce a gross pressure vessel component. The gross
pressure vessel component may be shaped as a hemisphere, a
cylinder, a cube, a rectangular prism, or any other suitable shape.
Portions of the gross pressure vessel component may have an
increased thickness located at predetermined positions on the gross
pressure vessel component. These portions may include bosses or
other designed features intended for the finalized pressure vessel
component. In some embodiments, the portions may occur at
predetermined angles of elevation and azimuth relative to a sphere
equatorial plane. The predetermined locations for the bosses may be
based on a plurality of possible arrangements of components with a
pressure vessel. In some embodiments, the gross pressure vessel may
be indexed to select the portions of the gross pressure vessel
component for machining. The selected portions may comprise only a
subset of the portions of the gross pressure vessel component
having an increased thickness. This subset may be determined based
on one of a plurality of possible component arrangements within the
pressure vessel. These selected portions may then be machined to
produce the pressure vessel component. In some embodiments, cable
pass-throughs (e.g., holes) may be machined at the portions having
the increased thickness. In some embodiments, the selected portions
are machined after casting and indexing the gross pressure vessel
component.
[0004] In some embodiments, the pressure vessel component may be
made from titanium. In alternate embodiments, any other suitable
materials may be used to produce the pressure vessel component,
including, but not limited to, steel, aluminum, or tungsten
carbide. Casting the metal may comprise sintering the metal
followed by a hot isostatic press (HIP) process. In alternate
embodiments, casting the metal may comprise pouring the molten
metal into a mold. In some embodiments, the pressure vessel
component may be heat treated, either before, during, or after
machining.
[0005] The pressure vessel component may be designed to mate with a
second pressure vessel component. As an illustrative example, the
pressure vessel component may comprise a hemisphere designed to
mate with another hemisphere to form a full sphere. The pressure
vessel component may use a hinge to open, close, and align with the
second pressure vessel component. In some embodiments, the hinge
may be a clam-like hinge. In some embodiments, at least a partial
vacuum may be formed in the cavity formed by the mated pressure
vessel component and the second pressure vessel component.
[0006] According to another aspect, a system for manufacturing a
pressure vessel component may comprise a mold for casting a metal
to produce a gross pressure vessel component. Portions of the gross
pressure vessel component having an increased thickness may be
located at predetermined positions on the gross pressure vessel
component. The system may further comprise machining equipment
configured to index the gross pressure vessel component to select
the portions of the gross pressure vessel component for machining.
The machining equipment may be used to machine the selected
portions to produce a pressure vessel.
[0007] Other objects, features, and advantages of the present
invention will become apparent upon examining the following
detailed description, taken in conjunction with the attached
drawings.
BRIEF DESCRIPTION OF THE FIGURES
[0008] The systems and methods described herein are set forth in
the appended claims. However, for purpose of explanation, several
illustrative embodiments are set forth in the following
figures.
[0009] FIG. 1 is a block diagram depicting an exemplary remote
vehicle, according to an illustrative embodiment of the present
disclosure.
[0010] FIG. 2 is block diagram of an exemplary computer system for
implementing at least a portion of the systems and methods
described in the present disclosure.
[0011] FIG. 3A depicts an illustrative pressure vessel
component.
[0012] FIG. 3B depicts an illustrative pressure vessel according to
one embodiment.
[0013] FIG. 3C depicts an illustrative pressure vessel according to
an alternate embodiment.
[0014] FIG. 4 depicts a process of manufacturing a pressure vessel
component according to an illustrative embodiment.
DETAILED DESCRIPTION
[0015] To provide an overall understanding of the invention,
certain illustrative embodiments will now be described. However, it
will be understood by one or ordinary skill in the art that the
systems and methods described herein can be adapted and modified
for other suitable applications and that such other additions and
modifications will not depart from the scope hereof.
[0016] Systems and methods are described herein of manufacturing a
pressure vessel component. The pressure vessel components may be
any suitable shape, including spherical, hemispherical,
cylindrical, or rectangular. The pressure vessel components may be
cast from titanium designed for use in the ocean. In one
embodiment, the pressure vessel may be a spherical titanium
pressure vessel with two hemispheres; one hemisphere may be used
for supporting the internal electronics chassis assembly, while the
other hemisphere may be adorned with external bosses for cable
pass-through to enable access to the internal electronics. The two
hemispheres may be sealed at the equatorial plane of the sphere
with an o-ring seal that enables safe operation of the internal
electronics at great depths. In some embodiments, a spherical form
factor pressure vessel may be designed to an appropriate
wall-thickness with a factor of safety to safely operate at a
pre-determined service depth (or pressure). To prevent slippage
between the hemispheres, the internal cavity may be evacuated to a
fraction of standard atmospheric pressure (i.e., <14.7 psi). The
spheres may be separated by removing the vacuum and subsequently
separating the hemispheres. Jack screws can be used to separate the
hemispheres, or the pressure inside the pressure vessel can be
increased to force the two sides apart. Internally, the pressure
vessel may or may not contain internal structure or electronics,
depending on the application.
[0017] A first pressure vessel component may be shaped as a
hemisphere and may have no external features or pass-throughs.
Thus, the first pressure vessel component may only require
machining on the interface surface. A flange may be machined to a
32 RMS finish to act as a sealing surface against the o-rings.
[0018] A second pressure vessel component may also be shaped as a
hemisphere, but may have both external features and a flange with
o-ring glands to enable watertight sealing during normal operation.
The o-ring gland may be machined into the equatorial flange at a
larger diameter than the nominal sphere outer diameter. This leaves
the spherical structural geometry intact to support compressive
loading.
[0019] Bosses may protrude from the exterior surface of the second
pressure vessel component. The bosses may comprise portions of
increased material thickness located at predetermined angles of
elevation and azimuth relative to the sphere equatorial plane.
These boss locations may be chosen to minimize stress and to
maximize the packing efficiency of connected cables and devices.
However, not all bosses may require post-casting machining. The
remaining bosses may remain as cast and left for modification at a
later time. When the bosses are machined, the pass-throughs may be
machined using watertight connectors that fasten to the outer face
of the sphere with threaded hardware (e.g., hex head screws). The
locations of the connector bolt-holes may be chosen to minimize
stress.
[0020] In some embodiments, a pressure vessel may have a
cylindrical form factor. The pressure vessel may consist of a main
body comprised of one or more cylindrical sections with end caps.
The end caps may be hemispheres or square-shaped. All components
may be designed to the appropriate wall-thickness with a factor of
safety to safely operate at a pre-determined service depth (or
pressure). The cylinder and sphere diameters may be concentric and
the same length and align for assembly.
[0021] During normal operation, the cylinder may be arranged such
that their sealing surfaces are joined to create a watertight seal
that carries the load to support compressive and bending moments.
Hemispheres may be situated at either end of the cylinder body and
may be sealed by use of an o-ring seal at a flange located at the
equatorial plane of the hemispheres. The internal cavity may be
evacuated to a fraction of standard atmospheric pressure (i.e.,
<14.7 psi). To facilitate internal access, the hemispheres may
be separated from the cylinders by removing the vacuum and
subsequently removing the band clamps. Internally, the pressure
vessel may or may not contain internal structure or electronics,
depending on the application.
[0022] For a manned submersible, the pressure vessel may be cast
with holes or bosses for windows.
[0023] In some embodiments, the manufacturing process may consist
of casting titanium to produce the gross pressure vessel component
shapes, including any boss features. As discussed above, the boss
features may be cast into their final shape, or the boss features
may require additional machining to achieve a final shape. The
manufacturing process may comprise several steps: casting a metal
(such as titanium), indexing the cast part for machining, and
machining specific regions of the cast part. Heat treating is
optional and may be unnecessary for thinner walled pressure
vessels. The casting process chosen may depend upon the wall
thickness and size of the part being cast. In some embodiments, the
casting process may comprise sintering a metal followed by a hot
isostatic press (HIP) process. In alternate embodiments, the
casting process may comprise pouring molten metal into a mold, such
as a lost-wax or a graphite mould.
[0024] In some embodiments, the pressure vessel may be sealed by
partially evacuating the internal cavity through a dual seal vent
plug valve of the sphere so that the hemisphere flanges engage
under the force generated by the relative pressure difference
between inside and outside the sphere. A "band" clamp may be
affixed to the flanges of the hemispheres to provide additional
clamping force, for example, during shallow water operation. The
clamp may contain an equally-spaced hole pattern for bolting with
threaded hardware. The spherical pressure vessel band clamp may
contain eye bolts that can be shackled to straps for lifting and
handling of the sphere pre and post mission. When the pressure
vessel is opened, the hemispheres may need to rest securely in a
holder. In one embodiment, a plastic plate cut with a hole larger
than the hemisphere and a finger access pattern that matches the
band clamp bolt pattern may be used. Alternatively, a band clamp
can be applied to both hemispheres and connected via a hinge. In
some embodiments, the spherical pressure vessel band clamp may
double as a mounting bracket.
[0025] In some embodiments, a cylindrically-shaped pressure vessel
may be sealed by bolting the cylindrical section flanges together
to create a structurally watertight seal. The internal cavity may
be partially evacuated through a dual seal vent plug valve,
allowing the hemisphere end cap flanges to engage under the force
generated by the relative pressure difference between inside and
outside the housing.
[0026] In some embodiments, additional features may be cast into
the pressure vessel component to simplify internal mounting of
components. The internal mounts may feature slotted holes to
prevent the application of stress as the pressure vessel shrinks
under pressure. Likewise, flexible standoffs may be applied to the
inside of the pressure vessel component when mounting objects such
as electronics to prevent the transfer of stress as the pressure
vessel component shrinks under pressure. This protects the
electronics from damage and protects the pressure vessel component
from asymmetric loading.
[0027] Titanium is a poor heat conductor and therefore expunging
internal heat (i.e., generated from electronics) typically requires
the use of a radiator. In some embodiments, radiators may include a
beryllium copper radiator for liquid cooling. The coolant may be a
non-conducting and a non-flammable coolant, such as Fluorinert, or
Opticool, rather than normal engine coolant (which conducts) or
distilled water (which is non-conducting, but in the event of a
leak is difficult to guarantee purity).
[0028] FIG. 1 is a block diagram depicting an illustrative remote
vehicle, according to an illustrative embodiment of the present
disclosure. The system 100 includes a sonar unit 110 for sending
and receiving sonar signals, a preprocessor 120 for conditioning a
received (or reflected) signal, and a matched filter 130 for
performing pulse compression and beamforming. The system 100 is
configured to allow for navigating using high-frequency (greater
than about 100 kHz) sonar signals. To allow for such HF navigation,
the system 100 includes a signal corrector 140 for compensating for
grazing angle error and for correcting phase error. The system 100
also includes a signal detector 150 for coherently correlating a
received image with a map. In some embodiments, the system 100
includes an on-board navigation controller 170, motor controller
180 and sensor controller 190. The navigation controller 170 may be
configured to receive navigational parameters from a GPS/RF link
172 (when available), an accelerometer 174, a gyroscope, and a
compass 176. The motor controller 180 may be configured to control
a plurality of motors 182, 184 and 186 for steering the vehicle.
The sensor controller 190 may receive measurements from the battery
monitor 172, a temperature sensor 194 and a pressure sensor 196.
The system 100 further includes a central control unit (CCU) 160
that may serve as a hub for determining navigational parameters
based on sonar measurements and other navigational and sensor
parameters, and for controlling the movement of the vehicle.
[0029] In the context of a surface or underwater vehicle, the CCU
160 may determine navigational parameters such as position
(latitude and longitude), velocity (in any direction), bearing,
heading, acceleration and altitude. The CCU 160 may use these
navigational parameters for controlling motion along the alongtrack
direction (fore and aft), acrosstrack direction (port and
starboard), and vertical direction (up and down). The CCU 160 may
use these navigational parameters for controlling motion to yaw,
pitch, roll or otherwise rotate the vehicle. During underwater
operation, a vehicle such as an AUV may receive high-frequency real
aperture sonar images or signals at sonar unit 110, which may then
be processed, filtered, corrected, and correlated against a
synthetic aperture sonar (SAS) map of the terrain. Using the
correlation, the CCU may then determine the AUV's position, with
high-precision and other navigational parameters to assist with
navigating the terrain. The precision may be determined by the
signal and spatial bandwidth of the SAS map and/or the acquired
sonar image. In certain embodiments, assuming there is at least a
near perfect overlap of the sonar image with a prior SAS map with
square pixels, and assuming that the reacquisition was performed
with a single channel having a similar element size and bandwidth,
and assuming little or no losses to grazing angle compensation, the
envelope would be about one-half the element size. Consequently, in
certain embodiments, the peak of the envelope may be identified
with high-precision, including down to the order of about
1/100.sup.th of the wavelength. For example, the resolution may be
less than 2.5 cm, or less than 1 cm or less than and about 0.1 mm
in the range direction.
[0030] As noted above, the system 100 includes a sonar unit 110 for
transmitting and receiving acoustic signals. The sonar unit
includes a transducer array 112 having a one or more transmitting
elements or projectors and a plurality of receiving elements
arranged in a row. In certain embodiments the transducer array 112
includes separate projectors and receivers. The transducer array
112 may be configured to operate in SAS mode (either stripmap or
spotlight mode) or in a real aperture mode. In certain embodiments,
the transducer array 112 is configured to operate as a multibeam
echo sounder, sidescan sonar or sectorscan sonar. The transmitting
elements and receiving elements may be sized and shaped as desired
and may be arranged in any configuration, and with any spacing as
desired without departing from the scope of the present disclosure.
The number, size, arrangement and operation of the transducer array
112 may be selected and controlled to insonify terrain and generate
high-resolution images of a terrain or object. One example of an
array 112 includes a 16 channel array with 5 cm elements mounted in
a 123/4 inch vehicle.
[0031] The sonar unit 110 further includes a receiver 114 for
receiving and processing electrical signals received from the
transducer, and a transmitter 116 for sending electrical signals to
the transducer. The sonar unit 110 further includes a transmitter
controller 118 for controlling the operation of the transmitter
including the start and stop, and the frequency of a ping.
[0032] The signals received by the receiver 114 are sent to a
preprocessor for conditioning and compensation. Specifically, the
preprocessor 120 includes a filter conditioner 122 for eliminating
outlier values and for estimating and compensating for hydrophone
variations. The preprocessor further includes a Doppler compensator
124 for estimating and compensating for the motion of the vehicle.
The preprocessed signals are sent to a matched filter 130.
[0033] The matched filter 130 includes a pulse compressor 132 for
performing matched filtering in range, and a beamformer 134 for
performing matched filtering in azimuth and thereby perform
direction estimation.
[0034] The signal corrector 140 includes a grazing angle
compensator 142 for adjusting sonar images to compensate for
differences in grazing angle. Typically, if a sonar images a
collection of point scatterers the image varies with observation
angle. For example, a SAS system operating at a fixed altitude and
heading observing a sea floor path will produce different images at
different ranges. Similarly, SAS images made at a fixed horizontal
range would change if altitude were varied. In such cases, changes
in the image would be due to changes in the grazing angle. The
grazing angle compensator 142 is configured to generate grazing
angle invariant images. One such grazing angle compensator is
described in U.S. patent application Ser. No. 12/802,454 titled
"Apparatus and Method for Grazing Angle Independent Signal
Detection," the contents of which are incorporated herein by
reference in their entirety.
[0035] The signal corrector 140 includes a phase error corrector
144 for correcting range varying phase errors. Generally, the phase
error corrector 144 breaks the image up into smaller pieces, each
piece having a substantially constant phase error. Then, the phase
error may be estimated and corrected for each of the smaller
pieces.
[0036] The system 100 further includes a signal detector 150 having
a signal correlator 152 and a storage 154. The signal detector 150
may be configured to detect potential targets, estimate the
position and velocity of a detected object and perform target or
pattern recognition. In one embodiment, the storage 154 may include
a map store, which may contain one or more previously obtained SAS
images real aperture images or any other suitable sonar image. The
signal correlator 152 may be configured to compare the received and
processed image obtained from the signal corrector 140 with one or
more prior images from the map store 154.
[0037] The system 100 may include other components, not
illustrated, without departing from the scope of the present
disclosure. For example, the system 100 may include a data logging
and storage engine. In certain embodiments the data logging and
storage engine may be used to store scientific data which may then
be used in post-processing for assisting with navigation. The
system 100 may include a security engine for controlling access to
and for authorizing the use of one or more features of system 100.
The security engine may be configured with suitable encryption
protocols and/or security keys and/or dongles for controlling
access. For example, the security engine may be used to protect one
or more maps stored in the map store 154. Access to one or more
maps in the map store 154 may be limited to certain individuals or
entities having appropriate licenses, authorizations or clearances.
Security engine may selectively allow these individuals or entities
access to one or more maps once it has confirmed that these
individuals or entities are authorized. The security engine may be
configured to control access to other components of system 100
including, but not limited to, navigation controller 170, motor
controller 180, sensor controller 190, transmitter controller 118,
and CCU 160.
[0038] Generally, with the exception of the transducer 112, the
various components of system 100 may be implemented in a computer
system, such as computer system 200 of FIG. 2. More particularly,
FIG. 2 is a functional block diagram of a general purpose computer
accessing a network according to an illustrative embodiment of the
present disclosure. The holographic navigation systems and methods
described in this application may be implemented using the system
200 of FIG. 2.
[0039] The exemplary system 200 includes a processor 202, a memory
208, and an interconnect bus 218. The processor 202 may include a
single microprocessor or a plurality of microprocessors for
configuring computer system 200 as a multi-processor system. The
memory 208 illustratively includes a main memory and a read-only
memory. The system 200 also includes the mass storage device 210
having, for example, various disk drives, tape drives, etc. The
main memory 208 also includes dynamic random access memory (DRAM)
and high-speed cache memory. In operation and use, the main memory
208 stores at least portions of instructions for execution by the
processor 202 when processing data (e.g., model of the terrain)
stored in main memory 208.
[0040] In some embodiments, the system 200 may also include one or
more input/output interfaces for communications, shown by way of
example, as interface 212 for data communications via the network
216. The data interface 212 may be a modem, an Ethernet card or any
other suitable data communications device. The data interface 212
may provide a relatively high-speed link to a network 216, such as
an intranet, internet, or the Internet, either directly or through
another external interface. The communication link to the network
216 may be, for example, any suitable link such as an optical,
wired, or wireless (e.g., via satellite or 802.11 Wi-Fi or cellular
network) link. In some embodiments, communications may occur over
an acoustic modem. For instance, for AUVs, communications may occur
over such a modem. Alternatively, the system 200 may include a
mainframe or other type of host computer system capable of
web-based communications via the network 216.
[0041] In some embodiments, the system 200 also includes suitable
input/output ports or may use the Interconnect Bus 218 for
interconnection with a local display 204 and user interface 206
(e.g., keyboard, mouse, touchscreen) or the like serving as a local
user interface for programming and/or data entry, retrieval, or
manipulation purposes. Alternatively, server operations personnel
may interact with the system 200 for controlling and/or programming
the system from remote terminal devices (not shown in the Figure)
via the network 216.
[0042] In some embodiments, a system requires a processor, such as
a navigational controller 170, coupled to one or more coherent
sensors (e.g., a sonar, radar, optical antenna, etc.) 214. Data
corresponding to a model of the terrain and/or data corresponding
to a holographic map associated with the model may be stored in the
memory 208 or mass storage 210, and may be retrieved by the
processor 202. Processor 202 may execute instructions stored in
these memory devices to perform any of the methods described in
this application, e.g., grazing angle compensation, or high
frequency holographic navigation.
[0043] The system may include a display 204 for displaying
information, a memory 208 (e.g., ROM, RAM, flash, etc.) for storing
at least a portion of the aforementioned data, and a mass storage
device 210 (e.g., solid-state drive) for storing at least a portion
of the aforementioned data. Any set of the aforementioned
components may be coupled to a network 216 via an input/output
(I/O) interface 212. Each of the aforementioned components may
communicate via interconnect bus 218.
[0044] In some embodiments, the system requires a processor coupled
to one or more coherent sensors (e.g., a sonar, radar, optical
antenna, etc.) 214. The sensor array 214 may include, among other
components, a transmitter, receive array, a receive element, and/or
a virtual array with an associated phase center/virtual
element.
[0045] Data corresponding to a model of the terrain, data
corresponding to a holographic map associated with the model, and a
process for grazing angle compensation may be performed by a
processor 202. The system may include a display 204 for displaying
information, a memory 208 (e.g., ROM, RAM, flash, etc.) for storing
at least a portion of the aforementioned data, and a mass storage
device 210 (e.g., solid-state drive) for storing at least a portion
of the aforementioned data. Any set of the aforementioned
components may be coupled to a network 216 via an input/output
(I/O) interface 212. Each of the aforementioned components may
communicate via interconnect bus 218.
[0046] In operation, a processor 202 receives a position estimate
for the sensor(s) 214, a waveform or image from the sensor(s) 214,
and data corresponding to a model of the terrain, e.g., the sea
floor. In some embodiments, such a position estimate may not be
received and the process performed by processor 202 continues
without this information. Optionally, the processor 202 may receive
navigational information and/or altitude information, and a
processor 202 may perform a coherent image rotation algorithm. The
output from the system processor 202 includes the position to which
the vehicle needs to move to.
[0047] The components contained in the system 200 are those
typically found in general purpose computer systems used as
servers, workstations, personal computers, network terminals,
portable devices, and the like. In fact, these components are
intended to represent a broad category of such computer components
that are well known in the art.
[0048] It will be apparent to those of ordinary skill in the art
that methods involved in the systems and methods of the invention
may be embodied in a computer program product that includes a
non-transitory computer usable and/or readable medium. For example,
such a computer usable medium may consist of a read only memory
device, such as a CD ROM disk, conventional ROM devices, or a
random access memory, a hard drive device or a computer diskette, a
flash memory, a DVD, or any like digital memory medium, having a
computer readable program code stored thereon.
[0049] Optionally, the system may include an inertial navigation
system, a Doppler sensor, an altimeter, a gimbling system to fixate
the sensor on a populated portion of a holographic map, a global
positioning system (GPS), a long baseline (LBL) navigation system,
an ultrashort baseline (USBL) navigation, or any other suitable
navigation system.
[0050] FIG. 3A depicts an illustrative pressure vessel component.
Pressure vessel component 300 may comprise gross pressure vessel
component 302 and one or more bosses 304.
[0051] Although gross pressure vessel component 302 is depicted as
a hemisphere, the gross pressure vessel component 302 may be shaped
as any suitable shape, including a sphere, a cylinder, an
ellipsoid, a cube, or a rectangular prison. Gross pressure vessel
component 302 may be made from titanium or any other suitable
material. In some embodiments, the gross pressure vessel component
302 may be cast by sintering the metal followed by a HIP process.
In alternate embodiments, the gross pressure vessel component 302
may be cast by pouring molten metal into a mold. The gross pressure
vessel component 302 may be optionally heat treated.
[0052] Bosses 304 may be portions of the gross pressure vessel
component 302 having an increased thickness. Bosses 304 may be
located at predetermined positions on the gross pressure vessel
component 302. Although the bosses 304 are depicted in FIG. 3A as
holes, bosses 304 may comprise any designed features intended for
the finalized pressure vessel component. In some embodiments, the
bosses 304 may occur at predetermined angles of elevation and
azimuth relative to a sphere equatorial plane. In some embodiments,
the bosses 304 may comprise cable pass-throughs (e.g., holes).
[0053] FIG. 3B depicts an illustrative pressure vessel according to
one embodiment. Pressure vessel 310 includes top hemisphere 312,
bottom hemisphere 314, bosses 316, 318, 320, 322, 324, and 326, and
o-ring 328.
[0054] Top hemisphere 312 may be a pressure vessel component
similar to component 302 discussed in relation to FIG. 3A. Although
top hemisphere 312 is depicted in FIG. 3B as having bosses 316,
318, and 320, these bosses are shown merely for illustrative
purposes. Top hemisphere 312 may have any number of bosses located
at any suitable location, and in some embodiments, top hemisphere
312 may not have any bosses at all and comprise a smooth hemisphere
with no features. In some embodiments, the top hemisphere 312 may
be adorned with external bosses 316, 318, and 320 for cable
pass-through to enable access to internal electronics. These boss
locations may be chosen to minimize stress and to maximize the
packing efficiency of connected cables and devices. Top hemisphere
312 may include a flange (not shown) to act as a sealing surface
against an o-ring. In some embodiments, the flange on the top
hemisphere 312 is machined to a 32 RMS finish.
[0055] Bottom hemisphere 314 may be a pressure vessel component
similar to component 302 discussed in relation to FIG. 3A. Although
bottom hemisphere 314 is depicted in FIG. 3B as having bosses 322,
324, and 326, these bosses are shown merely for illustrative
purposes. Bottom hemisphere 314 may have any number of bosses
located at any suitable location, and in some embodiments, bottom
hemisphere 314 may not have any bosses at all and comprise a smooth
hemisphere with no features. In some embodiments, the bottom
hemisphere 314 may be used for supported an internal electronics
chassis assembly. Bottom hemisphere 314 may include a flange (not
shown) machined to a 32 RMS finish to act as a sealing surface
against an o-ring.
[0056] Bosses 316, 318, 320, 322, 324, and 326 may be portions of
top hemisphere 312 or bottom hemisphere 314 having an increased
thickness. Bosses 316, 318, 320, 322, 324, and 326 may be located
at predetermined positions on the top hemisphere 312 or the bottom
hemisphere 314. Although the bosses 316, 318, 320, 322, 324, and
326 are depicted in FIG. 3B as holes, bosses 316, 318, 320, 322,
324, and 326 may comprise any designed features intended for the
finalized pressure vessel component. In some embodiments, the
bosses 316, 318, 320, 322, 324, and 326 may occur at predetermined
angles of elevation and azimuth relative to a sphere equatorial
plane. In some embodiments, the bosses 316, 318, 320, 322, 324, and
326 may comprise cable pass-throughs (e.g., holes).
[0057] In some embodiments, the top hemisphere 312 and bottom
hemisphere 314 may be sealed at the equatorial plane of the sphere
with an o-ring seal 328 that enables safe operation of the internal
electronics at great depths. The o-ring seal 328 may be any
suitable o-ring for sealing the pressure vessel from water ingress.
In some embodiments, the top hemisphere 312 and bottom hemisphere
314 may be joined by one or more hinges, such as a clam-like hinge.
In some embodiments, the top hemisphere 312 and the bottom
hemisphere 314 may be designed to an appropriate wall-thickness
with a factor of safety to safely operate at a pre-determined
service depth (or pressure). To prevent slippage between the
hemispheres 312 and 314, the internal cavity may be evacuated to a
fraction of standard atmospheric pressure (i.e., <14.7 psi). The
hemispheres 312 and 314 may be separated by removing the vacuum and
subsequently separating the hemispheres 312 and 314. Internally,
the pressure vessel may or may not contain internal structure or
electronics, depending on the application.
[0058] FIG. 3C depicts an illustrative pressure vessel according to
an alternate embodiment. Pressure vessel 350 includes cylinder 352,
top hemisphere 354, bottom hemisphere 356, bosses 358, 360, and
362, and o-rings 364 and 366.
[0059] Cylinder 352 may be a pressure vessel component similar to
component 302 discussed in relation to FIG. 3A. Although cylinder
352 is depicted in FIG. 3C as having bosses 358, these bosses are
shown merely for illustrative purposes. Cylinder 352 may have any
number of bosses located at any suitable location, and in some
embodiments, Cylinder 352 may not have any bosses at all and
comprise a smooth hemisphere with no features. Cylinder 352 may
include a flange (not shown) machined to a 32 RMS finish to act as
a sealing surface against an o-ring. Pressure vessel 350 uses top
hemisphere 354 and bottom hemisphere 356 as endcaps. Although the
endcaps are depicted as hemispheres 354 and 356 in FIG. 3C, the
endcaps could be any suitable shape, such as circular disks or
square-shaped. The cylinder 352 and hemispheres 354 and 356 may
have concentric diameters and/or the same length to align for
assembly.
[0060] Top hemisphere 354 may be a pressure vessel component
similar to component 302 discussed in relation to FIG. 3A. Although
top hemisphere 354 is depicted in FIG. 3C as having bosses 360,
these bosses are shown merely for illustrative purposes. Top
hemisphere 354 may have any number of bosses located at any
suitable location, and in some embodiments, top hemisphere 354 may
not have any bosses at all and comprise a smooth hemisphere with no
features. In some embodiments, the top hemisphere 354 may be
adorned with external bosses 360 for cable pass-through to enable
access to internal electronics. These boss locations may be chosen
to minimize stress and to maximize the packing efficiency of
connected cables and devices. Top hemisphere 354 may include a
flange (not shown) machined to a 32 RMS finish to act as a sealing
surface against an o-ring.
[0061] Bottom hemisphere 362 may be a pressure vessel component
similar to component 302 discussed in relation to FIG. 3A. Although
bottom hemisphere 362 is depicted in FIG. 3C as having bosses 362,
these bosses are shown merely for illustrative purposes. Bottom
hemisphere 362 may have any number of bosses located at any
suitable location, and in some embodiments, bottom hemisphere 362
may not have any bosses at all and comprise a smooth hemisphere
with no features. In some embodiments, the bottom hemisphere 362
may be used for supported an internal electronics chassis assembly.
Bottom hemisphere 362 may include a flange (not shown) machined to
a 32 RMS finish to act as a sealing surface against an o-ring.
[0062] Bosses 358, 360, and 362 may be portions of top hemisphere
354 or bottom hemisphere 356 having an increased thickness. Bosses
358, 360, and 362 may be located at predetermined positions on the
top hemisphere 354 or the bottom hemisphere 356. Although the
bosses 358, 360, and 362 are depicted in FIG. 3C as holes, bosses
358, 360, and 362 may comprise any designed features intended for
the finalized pressure vessel component. In some embodiments, the
bosses 358, 360, and 362 may occur at predetermined angles of
elevation and azimuth relative to a sphere equatorial plane. In
some embodiments, the bosses 358, 360, and 362 may comprise cable
pass-throughs (e.g., holes).
[0063] In some embodiments, the cylinder 352, top hemisphere 354,
and bottom hemisphere 362 may be sealed with o-rings seal 364 and
366 to enable safe operation of the internal electronics at great
depths. The o-ring seals 364 and 366 may be any suitable o-ring for
sealing the pressure vessel from water ingress. In some
embodiments, the cylinder 352 and the hemispheres 354 and 356 may
be joined by one or more hinges, such as a clam-like hinge. In some
embodiments, the cylinder 352, top hemisphere 354, and the bottom
hemisphere 356 may be designed to an appropriate wall-thickness
with a factor of safety to safely operate at a pre-determined
service depth (or pressure). To prevent slippage between the
cylinder 352 and hemispheres 354 and 356, the internal cavity may
be evacuated to a fraction of standard atmospheric pressure (i.e.,
<14.7 psi). The cylinder 352 and hemispheres 354 and 356 may be
separated by removing the vacuum and subsequently separating the
cylinder 352 and hemispheres 354 and 356. Internally, the pressure
vessel may or may not contain internal structure or electronics,
depending on the application.
[0064] FIG. 4 depicts a process of manufacturing a pressure vessel
component according to an illustrative embodiment. Process 400 may
include casting a metal to produce a gross pressure vessel
component where casting includes forming portions of the gross
pressure vessel component having an increased thickness and being
located at predetermined positions on the gross pressure vessel
component (Step 402). The positions are "predetermined" because the
locations are determined before casting or forming the gross
pressure vessel. Then, indexing the gross pressure vessel component
to select the portions of the gross pressure vessel component for
machining (Step 404). Finally, machining the gross pressure vessel
component to produce a pressure vessel component, including
machining the selected portions (Step 406).
[0065] At step 402, a metal may be cast to produce a gross pressure
vessel component. The metal may be any suitable metal for pressure
vessels, including, but not limited to, titanium, steel, aluminum,
or tungsten carbide. In some embodiments, the gross pressure vessel
component may be cast by sintering the metal followed by a HIP
process. In alternate embodiments, the gross pressure vessel
component may be cast by pouring molten metal into a mold. In some
embodiments, the pressure vessel component may be optionally heat
treated, either before or after machining.
[0066] At step 404, the gross pressure vessel may be indexed to
select the portions of the gross pressure vessel component for
machining. The portions may include bosses having an increased
thickness located at predetermined positions on the gross pressure
vessel component. In some embodiments, the bosses may occur at
predetermined angles of elevation and azimuth relative to a sphere
equatorial plane. In some embodiments, the bosses may comprise
cable pass-throughs (e.g., holes).
[0067] At step 406, the gross pressure vessel component may be
machined to produce a pressure vessel component, including
machining the selected portions. As discussed above, some of the
selected portions may not require additional machining. However,
some of the selected portions may require machining to remove
extraneous material to produce a finalized boss shape.
[0068] In certain implementations, a pressure vessel component such
as, for example, pressure vessel component 302, top hemisphere 312,
bottom hemisphere 314, or cylinder 352, is machined after the
vessel component 302 has been cast with various bosses 304, 316,
318, 320, 322, 324, or 326. One advantage to forming bosses 304 at
the time of casting a pressure vessel component 302 is that a
standard set of bosses may be formed efficiently, but then the
manufacturer can determine which ones of the cast bosses 304 are to
be machined into portals or holes depending on the configuration
and/or arrangement of the components within the pressure vessel
component 302. This can be particularly advantageous when the
pressure vessel includes a metal such as titanium. Furthermore, a
common mold may be used for all pressure vessels, and bosses,
holes, supports, flanges, and other features may be machined after
casting/forging in order to produce a custom pressure vessel.
Hence, a plurality of bosses 304 are formed to enable hole
machining for multiple possible configurations, but then only a
subset or portion of the plurality of bosses 304 is subsequently
machined into holes or portals based on a selected configuration or
arrangement of components. In contrast, existing manufacturing
processes of pressure vessels typically includes casting a pressure
vessel, then determining the required locations of bosses/holes
based on the designed component configuration, and then forming the
bosses and holes at the determined locations after a pressure
vessel component has been cast. Such a process, while limiting the
number of bosses on a pressure vessel, is substantially more
time-consuming, costly, and inefficient as compared with the
advantageous process as described above where a set of bosses 304
are formed during the casting process and, after casting, a subset
of the bosses 304 are machined depending on the particular
configuration or arrangement of components within the pressure
vessel 302, 312, 314, 352, 354, 356.
[0069] It will be apparent to those skilled in the art that such
embodiments are provided by way of example only. It should be
understood that numerous variations, alternatives, changes, and
substitutions may be employed by those skilled in the art in
practicing the invention. Accordingly, it will be understood that
the invention is not to be limited to the embodiments disclosed
herein, but is to be understood from the following claims, which
are to be interpreted as broadly as allowed under the law.
* * * * *