Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
CA 02692648 2010-01-04
WO 2009/042269 PCT/US2008/069186
METHOD FOR READING AND WRITING DATA
WIRELESSLY FROM SIMULATED MUNITIONS
BACKGROUND OF THE INVENTION
[0001] Weapon simulation systems are commonly used for combat training and/or
shooting practice. Such systems are designed to simulate the effects of a
specific weapon
type with a specific computer-generated target. There are numerous different
types of
munitions that are compatible with any one weapon, such as a 40mm grenade
launcher
(manufacturer independent). Some of these round types include high explosive,
airburst,
star cluster, flare, smoke, and practice. Because of this, there have been
many attempts
by firearms simulation manufacturers to create a method for simulating
different types of
munitions to be used in weapon simulation systems and be able to monitor the
type of
munition used in the weapon simulation system.
[0002] One method for reading different round types on a mortar launcher was
using
different color charge rings and a compatible color sensor to detect which
charge ring is
installed on the mortar. The mortar would then communicate via contacts on the
mortar
and launcher once the mortar had come to rest. This system was limited in many
ways.
The largest problem was sunlight causing large offsets and incorrect readings
with the
color sensor. Another issue is the ability to pick up a difference in color.
Because the
colors had to have a significant difference in wavelength in order to detect
each one with
no errors, the round types were limited to less than ten. Additionally,
communicating via
electrical contacts proved to be unreliable due to corrosion and mechanical
bounce.
Lastly, there was no ability to store any other data on the round such as a
serial number or
CA 02692648 2010-01-04
WO 2009/042269 PCT/US2008/069186
usage data. Other methods for determining different round types suffer from
very similar
limitations.
[0003] Another example of a previous method for detecting round type is
described
in patent number 5,201,658. This implementation uses frequency resonance to
detect
different round types. There are a few disadvantages to using this type of
detection. The
most notable disadvantage is the inability to convey more information than
just the round
type. Additionally the round frequency is set by hardware design and cannot be
changed
without disassembling the round and replacing the resonant circuit.
SUMMARY OF THE INVENTION
[0004] A system and method for reading and writing data wirelessly from
simulated
munitions during a weapon simulation scenario includes a simulated weapon that
is in
electrical connection with a primary simulation computer and an instructor
computing
station. The simulated weapon includes an insert which will receive a
simulated
munition. The insert includes an antenna that is connected to an RFID
transceiver, with
the transceiver further being connected to a weapon controller. An RFID tag is
installed
within the simulated munition, with the RFID tag storing information about the
simulated
munition and transmitting that information to the weapon controller via the
RFID
transceiver when the simulated munition passes the antenna. The weapon
controller will
further transmit the simulated munition information to the primary simulation
computer
for proper identification in the weapon simulation.
BRIEF DESCRIPTION OF THE DRAWINGS
2
CA 02692648 2010-01-04
WO 2009/042269 PCT/US2008/069186
[0005] Figure 1 is a block diagram of the components of a weapon simulation
system
incorporating a simulated munition having wireless transmissions with a
controller of a
simulated weapon;
[0006] . Figure 2a is a side sectional exploded view of one embodiment of the
simulated munition used in the simulated weapon;
[0007] Figure 2b is a side sectional view of the assembled simulated munition
illustrated in Figure 2a;
[0008] Figure 3a is a perspective view of a first embodiment of an insert;
[0009] Figure 3b is a perspective view of a second embodiment of the insert;
[0010] Figure 4 is a composite side sectional view of the simulated munition
illustrated in Figure 2b combined with the insert illustrated in Figure 3 in a
simulated
weapon;
[0011] Figure 5 is a composite side sectional view of the simulated munition
combined with the insert as illustrated in Figure 4, the antenna having an
extended wrap
around the insert; and
[0012] Figure 6 is an exploded side sectional view of the simulated munition
with
respect to the insert, the antenna extending around the edge of the insert.
DESCRIPTION OF THE INVENTION
[0013] A system and method for reading and writing data wirelessly from
simulated
munitions 24 is illustrated in the attached Figures 1-6. Looking first to
Figure 1, a
weapons simulation system 10 is shown having a simulated weapon 12 that is in
electrical connection with a primary simulation computer 14, such as with a
serial or
3
CA 02692648 2010-01-04
WO 2009/042269 PCT/US2008/069186
wireless (e.g., Bluetooth) connection 15. The primary simulation computer 14
generates
an electronic simulation scenario displayed on a screen or monitor to train a
user in the
use of the simulated weapon 12, and monitors the use of the simulated weapon
12 in the
scenario. The primary simulation computer 14 is further in electrical
communication
with an instructor computing station 16, again such as with a serial or
wireless (e.g.,
Bluetooth) connection 17. The instructor computing station 16 may be any
computer or
similar device that allows the instructor to further monitor the user's
interaction and
control the weapon simulation.
[0014] The simulated weapon 12 has the appearance of an actual weapon, and
includes a weapon controller 18 that monitors the operation of various sensors
that are
used with the simulated weapon 12, such as a magazine present sensor, a
trigger sensor, a
safety sensor, a hammer position sensor, as well as others as conventionally
used with
various simulated weapons 12. The weapon controller 18 may be a conventional
microcontroller or microprocessor that is able to control operation of the
simulated
weapon 12, and it is additionally in electrical communication with a radio-
frequency
identification (RFID) transceiver 20 that is housed in the simulated weapon
12. As
discussed further herein, the RFID transceiver 20 is connected with an antenna
28, which
will communicate with an RFID transponder tag 26 housed in the simulated
munition 24
when the simulated munition 24 is used with the simulated weapon 12.
[0015] As a bit of background, RFID is an automatic identification method,
relying
on storing and remotely retrieving data using the RFID tags 26 or
transponders. The
RFID tag 26 is an object that can be applied to or incorporated into a product
or item for
the purpose of identification using radio waves. Some RFID tags 26 can be read
from a
4
CA 02692648 2010-01-04
WO 2009/042269 PCT/US2008/069186
very close proximity of the transceiver 20, while others may be meters away
and beyond
the line of sight of the reader, and still others may be accessible hundreds
of meters away.
Most RFID tags 26 contain at least two parts. The first part is an integrated
circuit for
storing and processing information, modulating and demodulating a radio
frequency (RF)
signal, and other specialized functions. The second component is an antenna
for receiving
and transmitting the signal to the transceiver 20.
[0016] Referring back to Figure 1, the RFID transceiver 20 is connected with
the
antenna 28 via an impedance matching circuit 22. The impedance matching
circuit 22
which is used to match the resistance of the transceiver 20 with the simulated
munition
24 for efficient operation. The RFID transponder tag 26 as described above is
placed
inside of the simulated munition round 24 to store information about what type
of
munition is being simulated in the system 10. This intelligent simulated
munitions round
24 is used in the simulated weapon 12. The RFID tag 26 also stores other data
including
serial numbers, usage data, service history, and other information useful for
either the
customer or the manufacturer. The RFID tag 26 is read by the RFID transceiver
20 that
is connected with the simulated weapon 12, the transceiver 20 being added on
or
supported in the simulated weapon 12. The communications between the RFID tag
26
and the RFID transceiver 20 are accomplished using an antenna 28. The RFID
transceiver 20 and the antenna 28 are connected through the impedance matching
circuit
board 22 and a coaxial cable 23. The RFID tag 26 is read by the RFID
transmitter 20
when the simulated munition 24 is inserted into the simulated weapon 12 and
after the
simulated munition 24 has been seated into the barrel 54 or launch tube of the
simulated
weapon 12. After the RFID tag 26 is read, the weapon controller 18 will make
decisions
CA 02692648 2010-01-04
WO 2009/042269 PCT/US2008/069186
based on what type of simulated munitions round was read from the RFID tag 26.
The
data read from the RFID tag 26 is communicated to the primary simulation
computer 14
and then to the instructor's computing station 16 so that instructor's
computing station 16
may visually and audibly display the information to the user.
[0017] Continuing to view Figure 1, the block diagram of the system 10 shows
the
data flow and processing blocks of the system 10. The instructor's computing
station 16
is used to control, monitor, and update the simulation being run in real-time
by a course
instructor. That is, the instructor's computing station 16 will generate the
graphics and
scenarios being used to interact and train the user of the simulated weapon
12. During
the simulation, the primary simulation computer 14 receives data and commands
from
both the instructor's computing station 16 and the weapon controller 18. The
primary
simulation computer 14 makes simulation decisions based on its programming and
displays feedback to the trainee via visual means such as a projector onto a
screen or
using a television or monitor (not illustrated).
[0018] There are two separate processing blocks within the simulated weapon 12
which can run independent of one another. The weapon controller 18 is
responsible for
controlling all weapon timing of outputs, the reading of various sensors
associated with
the simulated weapon 12, and communication with the primary simulation
computer 14.
The RFID transceiver 20 executes commands to the RFID tag or transponder 26
via the
antenna 28 and reads the responses from the RFID tag 26. The RFID transceiver
20
packetizes the data received from the RFID tag 26 and sends the data via a
serial bus 19
or another electrical connection to the weapon controller 18. The weapon
controller 18
reads the data in from the serial bus 19 and interprets the data from the RFID
tag 26 as
6
CA 02692648 2010-01-04
WO 2009/042269 PCT/US2008/069186
just another sensor. The weapon controller 18 will make decisions on how to
fire the
simulated weapon 12 based on the data from the RFID tag 26 along with other
weapon
sensors associated with the simulated weapon 12. The data from the RFID tag 26
gets re-
packetized in a different format and sent to the primary simulation computer
14 where it
is used for visual feedback to the trainee using the simulated weapon 12.
[0019] As an example, if the simulated munition 24 was designed to have a
round
type such as "Smoke," then, when the simulated weapon 12 is fired, the primary
simulation computer 14 will display smoke on screen corresponding to where the
round
was fired. However, if the round type of the simulated munition 24 is a high
explosive
grenade, then the primary simulation computer 14 will display an explosion on
screen.
Thus, various simulated munitions 24 may be incorporated into the training of
the user.
The data from the RFID tag 26 is also available to be viewed by the instructor
on the
instructor's computing station 16. It should further be noted that all of the
parts of the
system 10 used for RFID (seen within the dotted line in Figure 1) are
interchangeable
with other simulated weapons 12. In addition, note that mechanical changes
made be
required to meet space constraints for various simulated weapons 12.
[0020] The RFID tags 26 used in the illustrated system 10 are passive,
although it is
foreseen that other types of RFID tags 26 may be implemented. That is, RFID
tags are
generally passive, active or semi-passive. Passive tags require no internal
power source,
so they are only active when a reader is nearby to power them. In contrast,
semi-passive
and active tags require a power source, such as a small battery. For passive
RFID tags
that have no internal power supply, the minute electrical current induced in
the antenna
by the incoming radio frequency signal provides just enough power for the
integrated
7
CA 02692648 2010-01-04
WO 2009/042269 PCT/US2008/069186
circuit in the tag to power up and transmit a response. Passive tags have
practical read
distances ranging from about four inches up to a few almost 600 feet.
[0021] In comparison to passive RFID tags, active RFID tags have their own
internal
power source that is used to power the integrated circuit and to broadcast the
response
signal to the reader. Communications from active tags to readers is typically
much more
reliable than communications from passive tags. Due to their on board power
supply,
active tags may transmit at higher power levels than passive tags, allowing
them to be
more robust at longer distances and in different environments. Many active
tags today
have operational ranges of hundreds of meters, and a battery life of up to ten
years.
Active tags may include larger memories than passive tags, and may include the
ability to
store additional information received from the reader. Although the
embodiments shown
herein include passive RFID tags 26, it is noteworthy that an active or semi-
passive RFID
tag 26 could be implemented for the user to achieve the desired results.
[0022] Referring to Figures 2-6, various embodiments of the simulated weapon
12
and simulated munition 24 are illustrated. In these embodiments, a simulated
grenade
launcher is able to fire a simulated munition 24 in the form of a 40mm grenade
40.
Although a grenade is illustrated, various types of munitions could be
implemented.
Nonetheless, the simulated grenade 40 is composed of two parts similar to an
actual
40mm grenade, namely, a simulated projectile 42 and an aluminum cartridge case
44.
The simulated projectile 42 is created from a nylon rod turned down to match
the profile
of the live round. The inside of the projectile 42 is bored out and female
threads 46 are
cut into the diameter to mate with the cartridge case 44, also known as the
shell. The
cartridge case 44 may be made from aluminum, and has an outer diameter closely
8
CA 02692648 2010-01-04
WO 2009/042269 PCT/US2008/069186
resembling that of a live round. The cartridge case 44 also has a smaller
threaded
diameter 47 that threads into the nylon projectile 42. Once the cartridge case
44 is
threaded completely into the projectile 42, a small cavity 48 is defined for
the placement
of the RFID tag 26. In many cases depending on the munition being simulated,
the RFID
tag 26 may not completely and snugly fit into the small cavity 48. In such
cases, a spacer
50, such as a nylon spacer and/or one or more foam pads 49 may be included to
secure
the RFID tag 26 in place and help prevent malfunction of the RFID tag 26 from
unnecessary physical activity. Looking to Figures 2b and 4, the RFID tag 26 is
supported
by the foam pads 49a, 49b, with one foam pad 49b abutting the spacer 50.
[0023] Looking to Figure 3a, a thin walled insert 52 is designed to snugly fit
into or
abut an inner surface of the simulated weapon 12, such as the inner surface of
the barrel
54 of the simulated weapon 12 (although the insert 52 may be positioned
relative to other
components of the simulated weapon 12 as appropriate to the operation of the
weapon).
Looking to Figure 4, the barrel insert 52 is designed to fit into the barrel
54 of a simulated
launcher or firearm, and may be affixed to the barrel 54 or launcher using any
conventionally known method, such as glue, a press fit, or a screw or other
connector
extending through the barrel 54 and the insert 52. The barrel insert 52 has a
longitudinal
grove cut 56 that is used to house the coaxial cable 23 connecting the
transceiver board
with the antenna. A relief cut 58 in the barrel insert 52 extends along the
grove cut 56,
and is used to support the antenna impedance matching circuit board. Looking
to Figures
3a and 3b, the barrel insert 52 may additionally have at least one lateral
grove cut 60 at
one end of the longitudinal groove cut 56 around the circumference of the
barrel insert 52
to receive the coil antenna 28 for the RFID transceiver 26. In the embodiment
shown in
9
CA 02692648 2010-01-04
WO 2009/042269 PCT/US2008/069186
Figure 3a and 4, the coil antenna 28 will wrap around the barrel insert 52 a
limited
number of times, such as three wraps around the barrel insert 52. The number
of wraps
of the antenna 28 around the barrel insert 52 is inversely proportional to the
frequency
transmission. The fewer the wraps, the higher the frequency transmission..
However, it
is noted that multiple wraps of the antenna 28 around the barrel insert 52 may
be
incorporated into the design. For example, in the embodiment shown in Figure
3b, the
barrel insert 52 has three independent lateral groove cuts 60a, 60b, and 60c
that extend
around the circumference of the barrel insert 52 at one end of the
longitudinal groove cut
56. As a result, in this embodiment, there will be three instances in which
the RFID tag
26 will communicate with the antenna 28 as the simulated munition 24 is
inserted into the
barrel insert 52. Further, referring to the embodiment shown in Figure 5, the
antenna 28
may have multiple wraps around the insert 52, with approximately 100 wraps of
the
antenna 28 being illustrated in this embodiment. Furthermore, referring to
Figure 6,
another embodiment illustrates the antenna 28 be disposed at the end of the
insert 52. In
this embodiment, the RFID tag 26 will communicate with the RFID transceiver 20
as the
simulated munition 24 is brought into range of the antenna 28.
[0024] Once the simulated munition 20 is inserted into the barrel insert 52,
the RFID
tag 26 will generally be positioned within the circumference of the antenna
coil 28. The
position of the RFID tag 26 may vary according to the materials in the barrel
54 and the
particular application of the simulated munition 26, but it is desirable to
have the RFID
tag 26 positioned as close to the center of the circumference of the antenna
28 as
possible. In the embodiment shown in Figure 4, it is estimated that the RFID
tag 26 may
be positioned 0.25 inches above or below the plane of the circumference of the
antenna
CA 02692648 2010-01-04
WO 2009/042269 PCT/US2008/069186
28. The ends of the coil antenna 28 are attached to the impedance matching
circuit board
22 that fits into the relief 58 also cut into the barrel insert 52.
[0025] One end of the barrel insert 52 is a hollow recess 53 to receive the
simulated
40mm grenade round 40 inside of the barrel insert 52. The transceiver circuit
board 20
that controls communication with the RFID tag 26 is located on the simulated
weapon 12
where space allows. The coaxial cable 23 connects the antenna impedance
matching
circuit board 22 with the transceiver circuit board 20. The transceiver
circuit board 20
communicates with the weapon controller card 18 via an electronic connection,
such as a
serial data bus, to relay munitions data.
[0026] Utilizing radio-frequency identification for simulated munitions round
type
detection has many advantages. For example, the RFID tag 26 can be written to
or read
from at any time as long as it is within range of the antenna 28 connected to
the
transceiver 20. This provides the advantage of allowing the same hardware to
be used in
all applications of simulated weapons 12 with only slight changes in the
programming of
the RFID tag 26. If any data on the munitions round RFID tag 26 needs to be
updated, it
can be done at any time from a compatible RFID transceiver 20 without
requiring an
electrical connection to the RFID tag 26. This includes the round type,
service history,
and usage data. Additionally, the RFID tag 26 may require no power (if
passive, as
discussed above) and is purchased as a commercial off the shelf part at a very
small cost.
This provides a large cost savings over custom applications throughout the
life of the
product. The RFID tags vary in memory capacity from 32Bytes to more than
256Bytes.
As little as 32 Bytes would allow storage of 255 different round types and
several bytes
of service history and usage history. The round type could also be expanded
larger
11
CA 02692648 2010-01-04
WO 2009/042269 PCT/US2008/069186
however more than 255 round types may be excessive. This amount of data
storage
provides a very large advantage over other round type detection methods.
Lastly, due to
the wireless and contact-less nature of RFID, there are no mechanical
connections to
brake or maintain. This allows for a nearly maintenance free product with high
reliability.
[0027] Although the example of munitions described above was a grenade, it is
to be
noted that any other munition may be used in the system 10. For example, the
simulated
munition 24 may take the form of a bullet, a missile, a warhead, or some other
type of
munition used in practicing the use of a weapon.
[0028] A first prototype RFID antenna 28 was built around a plastic tube 52
that
allowed a round to be inserted into it for testing. A 40mm near-production
simulated
round was used with an RFID tag 26 installed. It had a read range of
approximately 2.5
inches from the coil antenna 28 along the centerline of the plastic tube. To
test a version
closer to production assembly, the barrel insert 52 was made out of nylon with
the relief
cut 58 for the impedance matching circuit board 22 and the coil antenna 28.
This barrel
insert 52 was placed into an aluminum tube with a 3/16 inch wall, which
closely models a
real barrel of a 40mm grenade launcher. Initially, the simulated aluminum
barrel 54 was
offsetting the resonate frequency of the antenna 28 enough for the RFID tag 26
to be
unreadable. After retuning the antenna 28, the system 10 was tested to have a
read range
of about three inches from the center of the coil antenna 28 along the
centerline of the
barrel 54.
[0029] Having thus described exemplary embodiments of a METHOD FOR
READING AND WRITING DATA WIRELESSLY FROM SIMULATED
12
CA 02692648 2010-01-04
WO 2009/042269 PCT/US2008/069186
MUNITIONS, it should be noted by those skilled in the art that the within
disclosures are
exemplary only and that various other alternatives, adaptations, and
modifications may be
made within the scope of the present invention. Accordingly, the invention is
not limited
to the specific embodiments as illustrated herein, but is only limited by the
following
claims.
13
