U.S. patent application number 11/753974 was filed with the patent office on 2007-12-13 for system and method to minimize laser misalignment error in a firearms training simulator.
Invention is credited to Bobby Hsiang-Hua Chung.
Application Number | 20070287134 11/753974 |
Document ID | / |
Family ID | 39589144 |
Filed Date | 2007-12-13 |
United States Patent
Application |
20070287134 |
Kind Code |
A1 |
Chung; Bobby Hsiang-Hua |
December 13, 2007 |
System and Method to Minimize Laser Misalignment Error in a
Firearms Training Simulator
Abstract
A weapon simulation system is used to correct the misalignment
between a laser of a simulated weapon and an aim point of the
simulated weapon. A compensation offset profile and a compensation
angle profile are stored in a weapon controller card in the
simulated weapon identifying the misalignment of the laser module
in the corresponding simulated weapon. The compensation offset
profile and compensation angle profile is transmitted from the
weapon controller card to a central computer, where the central
computer calculates the aim point of the simulated weapon using
said compensation offset profile and said compensation angle
profile from said weapon controller card. The position of the
simulated weapon with respect to a screen of the weapon simulation
system is further calculated using an RFID reader in electrical
communication with the weapon controller card and at least one RFID
tag positioned in a fire line mat, which transmits the position
information to said central computer.
Inventors: |
Chung; Bobby Hsiang-Hua;
(Atlanta, GA) |
Correspondence
Address: |
SMITH, GAMBRELL & RUSSELL
SUITE 3100, PROMENADE II
1230 PEACHTREE STREET, N.E.
ATLANTA
GA
30309-3592
US
|
Family ID: |
39589144 |
Appl. No.: |
11/753974 |
Filed: |
May 25, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60803307 |
May 26, 2006 |
|
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Current U.S.
Class: |
434/22 |
Current CPC
Class: |
F41A 33/02 20130101;
F41G 3/2655 20130101; F41G 3/2627 20130101; F41G 1/545 20130101;
F41G 3/326 20130101; G09B 19/00 20130101 |
Class at
Publication: |
434/022 |
International
Class: |
F41G 3/32 20060101
F41G003/32 |
Claims
1. In a weapon simulation system, a method for correcting the
misalignment error between a laser of a simulated weapon and an
actual aim point line of the simulated weapon, said method
comprising the steps of: a) storing a compensation offset profile
and a compensation angle profile in a weapon controller card in the
simulated weapon; b) transmitting said compensation offset profile
and said compensation angle profile from said weapon controller
card to a central computer; c) calculating the misalignment error
of an aim point on a screen of the aim point line by said central
computer using said compensation offset profile and said
compensation angle profile from said weapon controller card; and d)
identifying the actual aim point in the central computer by using
the misalignment error.
2. The method as described in claim 1, wherein prior to step a)
further comprising: measuring at a known reference plane a
compensation angle between the aim point line corresponding to the
position of the simulated weapon and a laser path generated by a
laser module in the simulated weapon to generate a compensation
angle profile.
3. The method as described in claim 1, wherein prior to step a)
further comprising: measuring at a known reference plane a
compensation offset between the aim point line corresponding to the
position of the simulated weapon and a laser path generated by a
laser module in the simulated weapon to generate a compensation
offset profile.
4. The method as described in claim 1, prior to step c), further
comprising the step of: determining position information of the
location of the simulated weapon with respect to a screen of the
weapon simulation system using an RFID reader and at least one RFID
tag positioned in a fire line mat, said RFID reader in electrical
communication with said weapon controller card; and transmitting
said position information from said weapon controller card to said
central computer for calculating the misalignment error of the aim
point on the screen.
5. The method as described in claim 4, further comprising the steps
of: connecting an RFID reader with the simulated weapon, said RFID
reader in electrical communication with said weapon controller
card.
6. The method as described in claim 1, wherein prior to step c),
further comprising: measuring the cant angle position of the
simulated weapon with a cant sensor in electrical communication
with said weapon controller card; and transmitting said cant angle
position from said weapon controller card to said central computer
to compensate the position of aim point.
7. A weapon simulation system minimizing laser misalignment error,
said weapon simulation system comprising: a central computer
controlling a weapon simulation; a simulated weapon having a laser
module and a sight; and a weapon controller card connected with
said simulated weapon and in electrical communication with said
central computer, said weapon controller card storing a
compensation offset profile and a compensation angle profile in
said weapon controller card.
8. The system as described in claim 7 further comprising a cant
sensor housed in said simulated weapon, said cant sensor in
electrical communication with said weapon controller card to
transmit a cant angle to said weapon controller card.
9. The system as described in claim 7 further comprising: a fire
line mat having at least one RFID tag positioned therein; and a
RFID reader in electrical communication with said weapon controller
card, said RFID reader connected to the simulated weapon to
identify the location of said simulated weapon when said RFID
reader detects said RFID tag, said weapon controller card
transmitting said compensation offsets and angle profile and said
location information to said central computer.
Description
CROSS REFERENCE TO RELATED PATENT APPLICATIONS
[0001] This non-provisional patent application claims priority from
provisional patent application 60/803,307, filed on May 26, 2006,
which is relied upon and incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to weapon simulation systems
having a sight, and, more particularly, to weapon simulation
systems having a sight with a laser to calculate the correct
orientation of a simulated weapon.
BACKGROUND OF THE INVENTION
[0003] Firearms training simulators train police and military
personnel with the proper use and handling of weapons without using
real firearms and their associated ammunition. The firearms
simulator is designed for indoor training in a safe environment,
and uses infrared laser modules housed in the barrel of a simulated
weapon as a means to determine where the weapon is pointing on a
two-dimensional screen. The distance between the student and the
screen is very short relative to real world distances since the
simulation is done in a typical interior room. In particular,
firing line distances of twenty feet are not uncommon for a screen
that may span thirty feet wide.
[0004] Students use the day or optical sight of the simulated
weapon to aim the firearm. In the real world, a process called
boresighting, which involves mechanically adjusting a weapon's
sight, is used to ensure that the sight of the simulated weapon is
calibrated correctly to the shooter. With boresighting, the barrel
is aimed at a point of reference, and is confirmed by an optical
reference. This may be achieved by using the eye to look through
the barrel, or by placing a suitable light source (e.g., a laser)
into the barrel. The sight is then aligned to the same point of
reference. Thus, once the firearm is boresighted, the sight can be
"zeroed" by firing live rounds.
[0005] For a weapon simulator, there is no projectile to verify the
accuracy of boresighting as with actual weapons. Consequently, an
electronic boresight is used to determine the offset necessary to
determine the relationship between the laser impact and line of
sight. Ideally, this electronic boresight should be able to define
the relationship without respect to where the student is aiming on
the screen. However, if there is any misalignment of the laser
relative to the sight, then the only correct point is at the point
of boresight and everywhere else would be incorrect.
[0006] An example of this problem of misalignment in the horizontal
direction (X) is illustrated in FIG. 1, wherein a simulated weapon
10 is aimed at a screen 12 bearing the system targets. The
simulated weapon 10 is shown in two positions 10A, 10B having a
corresponding aim point line 14A, 14B (the aim point line 14A, 14B
may be any reference aiming line, such as the sight aim point (a
line of sight) or barrel aim point), but the laser is projected
along laser line 16A, 16B. The simulated weapon 10A is shown at the
position at boresight. In order for the simulator to accurately
determine the relationship between the line of sight or the aim
point line 14 and the laser impact or laser line 16 over the entire
screen 12, certain factors must be known. These factors include the
amount of misalignment between the laser path 16 and line of sight
14. Because of the configuration of the room surrounding the weapon
simulator 10, any error caused by misalignment is amplified across
the horizontal span of the screen 12. That is, the projected length
18A, 18B into the plane of the screen 12 between the line of sight
or aim point 14 and laser impact 16 changes significantly with
changing position and orientation between the simulated weapon 10
and the screen 12 as shown in a comparison of the positions of
weapon simulator 10A and weapon simulator 10B in FIGS. 1 and 2. The
distance between the aim point line 14A and the actual laser line
16A of the first weapon position 10A is the error distance 18A, and
the distance between the aim point line 14B and the actual laser
line 16B of a second weapon 10B is the error distance 18B. Clearly
the second error distance 18B is much greater than the first error
distance 18A due to the orientation and position of each weapon
position 10A, 10B, such that a single measurement for correction of
the alignment error in the weapon 10A, 10B at different locations
will not properly work. Further, the occasional overlap in the
error distances 18A, 18B, as shown in FIG. 2, make it difficult for
a central computer 15 of the weapon simulation system to ignore and
compensate for this error since the misalignment could be large and
unpredictable because the origination of the laser path 16A, 16B
from corresponding weapon simulator 10A or 10B is not known. The
same type of misalignment errors occur in the vertical direction
(Y) as well.
[0007] One partial solution is to mechanically align the laser line
16 with the line of sight 14 in the horizontal direction (X).
However, because of tolerances in both the simulated weapon 10 and
the measurement fixture, a repeatable perfect alignment of the
laser line 16 may not be cost effective in a production
environment. In addition, the mechanical alignment would not
compensate any misalignment in the vertical direction (Y) since the
aim point requires a clear path of any obstructions, such as the
laser module, and readjustment would be necessary every time a new
type of sight is used.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 is a top view illustration of different aim points of
simulated weapons on a target or screen at different positions;
[0009] FIG. 2 is a top view illustration of different aim points of
simulated weapons on the target or screen at different positions as
illustrated in FIG. 1, with the weapons starting at different
positions;
[0010] FIG. 3 is a top view illustration from FIG. 1 showing a
first error reduction due to misalignment using ELPM;
[0011] FIG. 4 is a top view illustration from FIG. 1 showing a
second error reduction due to misalignment using ELPM and
LCSPS;
[0012] FIG. 4a is a top view illustration from FIG. 4 showing an
enlarged view of a simulated weapon illustrating offset and angle
misalignment in the horizontal direction;
[0013] FIG. 5 is an illustration of a simulated weapon user on a
student positioning system; and
[0014] FIG. 6 is an illustration of a simulated weapon having
components for error correction illustrating offset and angle
misalignment in the vertical direction.
DESCRIPTION OF THE INVENTION
[0015] A weapon simulation system and method to minimize laser
misalignment error in a firearms training simulator addresses the
problems in error correction found in conventional weapons
simulators, providing a more accurate and cost effective solution
to correcting the errors, is illustrated in the attached drawings.
The weapon simulation system 8 includes a simulated weapon 10
having a weapon controller card 24 that is in electrical
communication with a central computer 15, with the central computer
creating and controlling the simulation scenario broadcast on a
screen 12. The simulated weapon 10 includes a laser module 29 that
generates a laser line 16 to be directed at a simulated target
generated by the central computer 15 on the screen 12. Furthermore,
the central computer 15 will monitor when the simulated weapon 10
has been fired and control scenarios surrounding operation of the
simulated weapon 10 (such as when the simulated weapon experiences
a simulated malfunction).
[0016] Referring to FIGS. 3-6, accuracy of the measurement of the
laser line 16 location on the screen 12 is improved through the use
of an electronic laser profiling system or method (referred to as
"ELPS" or "ELPM") 20 in a simulated weapon 10 (see FIG. 6) and a
low-cost student positioning system (or "LCSPS") 22 in the
environment surrounding the simulated weapon 10 (see FIG. 5). More
specifically, the ELPS 20 can be used alone, as illustrated in FIG.
3, depending on the amount of error 21 that can be tolerated in a
particular weapon simulation system 8. That is, if the central
computer 15 assumes that the simulated weapon 10 is in a particular
predetermined location in the X, Y, and Z directions at all times
(as shown as 10A), even when the simulated weapon 10 is moved from
that location (as shown as 10B), the error 21 is determined by
having the central computer 15 extrapolate an assumed laser line
16C generated from simulated 10A rather than simulated weapon 10B
to calculate an assumed aim point line 14C. The error 21 is the
difference between the assumed aim point line 14C and the actual
aim point line 14B. Alternatively, both the ELPS 20 and LCSPS 22
may be employed to allow for the use of compensation offsets D, D2
and angles .theta., .theta.2 profiles relative to a known reference
plane P that are stored in each simulated weapon 10 for each of its
sights/optics to determine the error that is needed to be corrected
(see FIG. 4), and the aim point 17B is precisely located on the
screen 12 according to the actual aim line 14B, analogous to aim
point 17A being precisely located on the screen 12 according to the
actual aim line 14B since it is at the boresight position.
[0017] Referring to FIG. 6, the ELPS 20 incorporates the use of a
weapon controller card 24 in the simulated weapon 10. The weapon
controller card 24 includes a microprocessor/microcontroller having
an electronic memory that will store information characterizing the
alignment of a laser path 16 (emitted by laser module 29) relative
to the sights 27 affixed to the simulated weapon 10. The weapon
controller card 24 is connected with any sensors mounted in or
affixed to the simulated weapon 10, and handles communication
between the sensors and a central computer 15. More specifically,
the actual positions of the laser impact 16 are noted for the sight
27, typically at the time when the simulated weapon 10 is being
manufactured. The horizontal and vertical offsets D, D2 between the
sight 27 and the laser path 16 as well as the horizontal and
vertical angles .theta., .theta.2 between the aim point 14 and
laser line 16 are measured for each sight 27 relative to a known
reference plane P in order to ensure that the laser line 16 will
match the line of sight 14 at the specified firing line distance
19. This data is then stored in the weapon controller card 24,
which is housed in the simulated weapon 10. Because this
information is electronically stored in the simulated weapon 10
itself, there are no moving parts that can cause the information to
be incorrect (unlike mechanically corrected alignment between the
laser beam from laser module 29 and sights 27), and it guarantees
that any variations among designs of simulated weapon 10 will be
consistent and minimized.
[0018] The weapon controller card 24 stores this profile data
(including compensation offset profiles and compensation angle
profiles) electronically in the simulated weapon 10 to provide the
adjustment information to the central computer 15 for the weapon
simulation system 8. The ELPS 20 uses the offsets D, D2 from the
aim point 14 of the simulated weapon 10 as a comparison to the
actual laser hit 16 at the firing line distance 19 and the angles
.theta., .theta.2 between the aim point lines 14A, 14B and the
laser lines 16A, 16B relative to the sights 27. The ELPS 20 will
allow the central computer 15 of the weapon simulator 10 to
calculate the correct offset for any path in which the laser path
16 will follow at distances different from the boresighted point to
allow the weapon simulator 10 to correct any misalignment of the
laser path 16 if the position of the weapon simulator 10 is known
(that is, the position of the simulated weapon from the target on
the screen 12).
[0019] Using the ELPS 20, the boresighting of the laser path 16 can
be more exact, consistent, and robust, unlike a mechanical
adjustment that will always have some tolerance stack up and human
error, and will further be subjected to mechanical damage. Once the
simulated weapon 10 is registered on the weapon controller card 24,
the particular electronic laser profile will be downloaded to the
central computer 15 of the weapon simulation system 8 so that the
central computer 15 can adjust the laser position 16 electronically
to compensate for any misalignment or error distance 18A, 18B due
to mechanical tolerances in the manufacturing process.
[0020] Once the offsets D, D2 and the departing angles .theta.,
.theta.2 of the laser beam 16 relative to the line of sight 14 are
known from the weapon controller card 24, the next step is to
determine the originating position of laser on the weapon simulator
10 using the LCSPS 22. Since the firing line 16A, 16B is a known or
assumed distance 16 from the screen 12 (in the Z-direction), the
unknowns are that are needed to truly determine the student's aim
point in the simplified two-dimensional illustration are the
horizontal position (or X-direction) and the vertical position (or
Y-direction). However, in order to realize this method into
three-dimensional space, the cant of the simulated weapon 10 is a
factor and must be included in the calculations to determine the
actual aim point. Consequently, a cant sensor 31 is included in the
weapon simulator 10 to determine the cant angle of the simulated
weapon 10 and transmit the corresponding information to the weapon
controller card 24, which is in electrical communication with the
central computer 15 to factor in the cant angle in determining the
position of the weapon controller card 24. The cant sensor 31 is
needed because there is a physical offset between the laser module
29 and the aim point line 14, and the cant angle occurs when the
student does not hold the simulated weapon 10 in a substantially
vertical position.
[0021] The LCSPS 22 can determine the unknown X- and Y-positions of
the simulated weapon 10 through the use of Radio Frequency
Identification (or "RFID"). RFID technology is designed to be a
very low cost means for product identification and tracking, and
has been adopted by the military and retail sector as a "smart"
alternative way of bar coding products for specific identification.
More specifically, the RFID system uses RFID tags 26 and an RFID
reader 28 to monitor an item. Referring to FIG. 5, the LCSPS 22
includes a fire line mat 30 having the RFID tags 26 embedded in a
grid system at known, pre-determined distances with respect to the
fire line mat 30. The RFID tags 26 are distributed in the fire line
mat 30 according to the amount of error that can be tolerated in a
particular system. That is, the more RFID tags 26 that are used in
a fire line mat 30, the more accurate the measurement of the RFID
reader 28 of the position of the user 6.
[0022] RFID tags 26 require no external power source; rather, the
power is generated by the radio frequency energy that is
transmitted to each RFID tag 26. The identification of each RFID
tag 26 is the distance from a reference tag. The RFID reader 28 can
have sensing distance of about six feet. Therefore, the RFID reader
28 can read any RFID tag 26 within its range to determine the
actual position of the simulated weapon 10 and student along the
firing line mat 30. The RFID reader 28 can be located in or
proximate the simulated weapon 10, and the RFID reader 28
communicates with the weapon controller card 24 of the simulated
weapon 10. The weapon controller card 24 is in communication with
the central simulation computer 15 (via either a wireless or wired
connection 23), and transmits the position of the simulated weapon
10 to the central simulation computer 15 as part of the firing
packet of the simulated weapon 10 so that the central simulation
computer 15 can use this information and the data from the ELPS 20
to compensate for the error caused by physical misalignment of the
sight 27 and laser line 16. This method of sensing the position of
the simulated weapon 10 will continuously monitor the position of
the student to allow the student to move around during a simulation
exercise.
[0023] Alternatively, if the simulation does not require the
students to move from a single location, then the student's
position can be entered into the simulation computer 15 by the
instructor at the beginning of an exercise. In this way, the use of
an LCSPS 22 or any other position sensing technology is not
necessary and only the ELPS 20 is used to compensate the
misalignment error.
[0024] Having thus described exemplary embodiments, 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 this disclosure
as described herein and as described in the appended claims.
* * * * *