U.S. patent application number 11/870666 was filed with the patent office on 2008-02-07 for multi-dimensional measuring system.
Invention is credited to KAM C. LAU.
Application Number | 20080030855 11/870666 |
Document ID | / |
Family ID | 33134807 |
Filed Date | 2008-02-07 |
United States Patent
Application |
20080030855 |
Kind Code |
A1 |
LAU; KAM C. |
February 7, 2008 |
MULTI-DIMENSIONAL MEASURING SYSTEM
Abstract
A laser based tracking unit communicates with a target to obtain
position information about the target. Specifically, the target is
placed at the point to be measured. The pitch, yaw and roll
movements of the target, and the spherical coordinates of the
target relative to the tracking unit are then obtained. The target
can be, for example, an active device incorporated into a moveable
device such as a remote controlled robot.
Inventors: |
LAU; KAM C.; (Potomac,
MD) |
Correspondence
Address: |
PILLSBURY WINTHROP SHAW PITTMAN, LLP
P.O. BOX 10500
MCLEAN
VA
22102
US
|
Family ID: |
33134807 |
Appl. No.: |
11/870666 |
Filed: |
October 11, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11761147 |
Jun 11, 2007 |
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11870666 |
Oct 11, 2007 |
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10646745 |
Aug 25, 2003 |
7230689 |
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11761147 |
Jun 11, 2007 |
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60405712 |
Aug 26, 2002 |
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Current U.S.
Class: |
359/529 |
Current CPC
Class: |
G01C 15/002 20130101;
G01B 11/002 20130101; G01S 7/499 20130101; G01S 5/163 20130101;
G01S 17/66 20130101 |
Class at
Publication: |
359/529 |
International
Class: |
G02B 5/122 20060101
G02B005/122 |
Claims
1. A target associated with a multi-dimensional measuring system
comprising: a retro-reflector having an apex, wherein the apex is
configured to allow at least part of a laser beam light entering
the retro-reflector to exit the retro-reflector; and a laser light
sensor configured to detect the at least part of the laser beam
light exiting the retro-reflector through the apex.
2. The target of claim 1, wherein the target is configured to be
coupled to an optical measuring sensor.
3. The target of claim 1, wherein the retro-reflector is a hollow
retro-reflector.
4. The target of claim 3, wherein the retro-reflector comprises an
aperture at the apex, the aperture is configured to allow the at
least part of the laser beam light to exit the retro-reflector.
5. The target of claim 3, wherein the retro-reflector comprises
three mirrors that form the apex.
6. The target of claim 1, wherein the retro-reflector is a solid
retro-reflector.
7. The target of claim 6, wherein the apex comprises a small flat
surface polished to allow the at least part of the laser beam light
to exit the retro-reflector.
8. The target of claim 1, wherein the laser light sensor is a
photodetector.
9. The target of claim 1, wherein the laser light sensor is a
charge coupled device array sensor.
10. The target of claim 1, wherein the laser light sensor is
operable to detect at least one of the pitch and yaw movements of
the target.
Description
[0001] This application is a divisional application of co-pending
U.S. patent application Ser. No. 11/761,147 filed Jun. 11, 2007,
which is a divisional application of co-pending U.S. patent
application Ser. No. 10/646,745 filed Aug. 25, 2003, which claims
priority to U.S. Provisional Patent Application No. 60/405,712
filed Aug. 26, 2002, all of which are hereby incorporated herein by
reference in their entirety.
BACKGROUND
[0002] 1. Field of the invention
[0003] The present invention relates generally to a measuring
system. In particular, the systems and methods of this invention
are directed toward a multi-dimensional laser tracking system.
[0004] 2. Background of the Invention
[0005] Precision measuring systems have a wide variety of
applications. For example, in robotics, accurate positioning and
orientation of a robot is often required. To achieve a high degree
of precision, a robot position measuring system can be used. Such a
system typically uses a laser beam interferometer to determine the
position and/or orientation of an end-effector of the robot. Such
system can monitor the position and orientation of the robot
end-effector in real-time while providing accuracy, speed and
measurement data.
[0006] For example, a Three and Five Axis Laser Tracking System is
discussed in Applicant's U.S. Pat. No. 4,714,339, and a
Five-Axis/Six-Axis Laser Measuring System is discussed in
Applicant's U.S. Pat. No. 6,049,377, both of which are incorporated
herein by reference in their entirety. in addition, Applicant's
U.S. Application No. 60/377,596, entitled "Nine Dimensional Laser
Tracking System and Method," which was filed on May 6, 2003, is
also incorporated herein by reference in its entirety to provide
additional description for the present invention.
BRIEF SUMMARY OF THE INVENTION
[0007] One aspect of the invention provides multi-dimensional
measuring system that includes a tracking unit, a target, a
distance determining module, and an output module. The tracking
unit emits laser light and performs tracking using spherical
coordinates. The target is in communication with the tracking unit.
The target is capable of making pitch, yaw, and roll movements. The
distance determining module determines a distance between the
tracking unit and the target. The output module outputs position
information about the target relative to the tracking unit based on
the spherical coordinates, the pitch, yaw and roll movements, and
the distance.
[0008] Preferably, the system further includes an output device
that outputs the position information about the target. Preferably,
the roll movement is based on at least one of a comparison between
a horizontally polarized component of the laser light and a
vertically polarized component of the laser light. Preferably, the
system further includes a first photodetector that detects the
horizontally polarized component of the laser light and a second
photodetector that detects the vertically polarized component of
the laser light. Preferably, the system further includes a roll
determination circuit that receives an output of the first
photodetector and an output of the second photodetector. In an
alternative embodiment, the system uses an electronic level to
measure roll movements of the target.
[0009] Preferably, the target is an active target that is capable
of moving relative to the tracking unit. Preferably, the target is
at least one of incorporated into a remote unit, fixably attached
to an object, used for feedback control, used for calibration, used
for machine tool control, used for parts assembly, used for
structural assembly, and used for dimensional inspection.
Preferably, the remote unit is a robot. Preferably, the robot
includes a drive system and one or more traction devices that allow
the robot to adhere to a surface. Preferably, the traction devices
are suction cup type devices. Alternatively, a positive air
pressure system can be used to maintain the remote unit movably
attached to the surface. Preferably, the system further includes a
vacuum system. Preferably, the system further includes one or more
accessories that allow a function to be performed based at least on
the position information of the target.
[0010] Another aspect of the invention provides a remote unit
associated with a multi-dimensional measuring system. The remote
unit includes a target and probe assembly coupled to the target.
The target is in communication with a tracking unit of the
multi-dimensional measuring system. The target is capable of making
pitch, yaw, and roll movements. The probe assembly includes a probe
tip, a probe stem, and a probe base. The probe tip is configured to
reach locations that are not in a line of sight between the
tracking unit and the target.
[0011] Preferably, the remote unit further includes one or more
encoders coupled to the probe assembly. Preferably, at least one of
the encoders is configured to determine a first angular position of
the probe tip relative to the probe base. Preferably, at least one
of the encoders is configured to determine a second angular
position of the probe tip relative to the probe base. Preferably,
at least one of the encoders is configured to determine an axial
position of the probe tip relative to the probe base.
[0012] Preferably, the remote unit further includes a trigger
configured to effect one or more measurements associated with a
location touched by the probe tip. Alternatively, the remote unit
can include a touch sensor associated with the probe tip. One or
more measurements associated with a location is taken when the
touch sensor comes into contact with the location.
[0013] In another aspect, the invention relates to a target
associated with a multi-dimensional measuring system. The target
includes a retro-reflector and a laser light sensor. The
retro-reflector has an apex. The apex is configured to allow at
least part of a laser beam light entering the retro-reflector to
exit the retro-reflector. The laser light sensor is configured to
detect the at least part of the laser beam light exiting the
retro-reflector through the apex. Preferably, the target is
configured to be coupled to an optical measuring sensor.
[0014] The retro-reflector is preferably a hollow retro-reflector.
The retro-reflector includes an aperture at the apex. The aperture
is configured to allow the at least part of the laser beam light to
exit the retro-reflector. Preferably, the retro-reflector includes
three mirrors that form the apex.
[0015] The retro-reflector may alternatively be a solid
retro-reflector. The apex of the solid retro-reflector includes a
small flat surface polished to allow the at least part of the laser
beam light to exit the retro-reflector.
[0016] The laser light sensor can be a photodetector.
Alternatively, the laser light sensor can be a charge coupled
device array sensor. Preferably, the laser light sensor is operable
to detect at least one of the pitch and yaw movements of the
target.
[0017] Another aspect of the invention provides a method for
measuring a position of an object. Exemplary steps of the method
includes: (1) monitoring spherical coordinates of a laser light
emitting tracking unit; (2) monitoring pitch, yaw, and roll
movements of a target in communication with the tracking unit; (3)
determining a distance between the tracking unit and the target;
and (4) outputting position information about the target relative
to the tracking unit based on the spherical coordinates, the pitch,
yaw, and roll movements, and the distance. It is noted that the
method does not necessarily have to follow the order described
above.
[0018] Preferably, the roll movement is based on at least one of a
comparison between a horizontally polarized component of a laser
light emitted by the tracking unit and a vertically polarized
component of the laser light. Preferably, a roll determination
circuit performs the comparison between the horizontally polarized
component of the laser light and the vertically polarized component
of the laser light.
[0019] In another aspect, the invention includes a system for
measuring the position of an object that includes: (1) means for
monitoring spherical coordinates of a laser light emitting tracking
unit; (2) means for monitoring pitch, yaw, and roll movements of a
target in communication with the tracking unit; (3) means for
determining a distance between the tracking unit and the target;
and (4) means for outputting position information about the target
relative to the tracking unit based on the spherical coordinates,
the pitch, yaw, and roll movements, and the distance.
[0020] Accordingly, in accordance with an exemplary embodiment of
the invention, aspects of the invention relate to a
multi-dimensional measuring system.
[0021] An additional aspect of the invention relates to determining
roll movements of a target based on measurements from a polarized
laser.
[0022] Additionally, aspects of the invention relate to the design
and use of an active target in conjunction with a tracking
unit.
[0023] Additionally, aspects of the invention relate to the use of
target on a remote unit coupled with a trigger or a touch
sensor.
[0024] Additional aspects of the invention relate to a remotely
controlled robot that incorporates active target technology.
[0025] Additional aspects of the invention relate to a
retro-reflector being used in a target of a multi-dimensional
measuring system.
[0026] Additional aspects of the invention relate to methods for
calibrating a vector of a probe tip.
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] FIG. 1 is a schematic diagram illustrating an exemplary
multi-dimensional measuring system of the invention.
[0028] FIG. 2 is a schematic diagram illustrating a roll
determination system of the invention.
[0029] FIG. 3 is a schematic diagram illustrating an exemplary
pitch, yaw, roll, and distance measuring system of the
invention.
[0030] FIG. 4 is a schematic diagram illustrating an exemplary
remote unit incorporating an exemplary target of the invention.
[0031] FIG. 5 is a schematic cross-sectional view of an exemplary
remote controlled robot of the invention.
[0032] FIG. 6 is a flowchart illustrating an exemplary method of
taking measurements according to the invention.
[0033] FIG. 7 is a schematic diagram illustrating an exemplary
multi-dimensional measuring system of the invention that includes
an exemplary tracking unit and an exemplary remote unit.
[0034] FIG. 8 is a schematic diagram illustrating another exemplary
remote unit of the invention.
[0035] FIG. 9 is a schematic diagram illustrating an exemplary
probe assembly of the invention.
[0036] FIG. 10 is a schematic diagram illustrating another
exemplary probe assembly of the invention.
[0037] FIG. 11 is a schematic diagram illustrating another
exemplary probe assembly of the invention.
[0038] FIG. 12 is a schematic diagram illustrating an exemplary
remote unit of the invention.
[0039] FIG. 13 is a schematic diagram illustrating a front view of
the exemplary remote unit shown in FIG. 12.
[0040] FIG. 14 is a two-dimensional schematic diagram showing
another exemplary embodiment of a target of the invention that
includes a retro-reflector.
[0041] FIG. 15 is a three-dimensional schematic diagram showing the
exemplary embodiment of FIG. 14.
[0042] FIG. 16 is an exemplary hollow retro-reflector of the
invention.
[0043] FIG. 17 is an exemplary solid retro-reflector of the
invention.
[0044] FIG. 18 is a schematic diagram showing another exemplary
embodiment of a remote unit of the invention that includes an
optical measuring sensor.
[0045] FIG. 19 is a schematic diagram showing an exemplary system
for establishing the vector of a probe tip relative to an origin of
a target associated with the probe tip.
[0046] FIG. 20 is a flowchart illustrating an exemplary method of
establishing the vector of the probe tip depicted in FIG. 19.
DETAILED DESCRIPTION OF THE INVENTION
[0047] The systems and methods of this invention employ a
combination of a tracking unit and a target to accomplish
multi-dimensional laser tracking. For example, in a six-dimensional
(6-D) system of the invention, the six dimensions are pitch, yaw,
and roll movements of a target, and the spherical coordinates,
i.e., the 2 angles .alpha., .theta. and the radial distance, of the
target relative to the tracking unit. The target is preferably an
active target, which can be held by a person, a robot, or another
moving object. By using an active target, target coordinates
maintain a relatively perpendicular relation to the incoming beam
originated from the tracking unit. Additionally, by employing an
absolute distance measurement (ADM) technique, absolute ranging is
possible.
[0048] In general, the pitch and yaw based measurements can be
derived from an encoder present on the target. The roll
measurements can be based on, for example, a polarization or an
electronic level technique discussed below. The absolute distance
measurements or ADM can be accomplished using, for example,
repetitive time of flight (RTOF) pulses, a pulsed laser,
phase/intensity modulation, or the like. Additional description can
be found in Applicant's U.S. Patent Application No. 60/377,596, the
entirety of which is incorporated herein by reference.
[0049] Specifically, an RTOF based system includes a photodetector,
such as a PIN photodetector, a laser amplifier, a laser diode., and
a frequency counter. A first laser pulse is fired to the target.
Upon detecting the return pulse, the detector triggers the laser
amplifier and causes the laser diode to fire a second pulse, with
the pulses being detected by the frequency counter. However, it is
to be appreciated that the reverse logic also works with equal
success. The distance (D) of the target from the tracking unit can
then be calculated by: D = C 4 .times. ( 1 f - 1 f 0 ) ##EQU1##
such that: D=0;f=f.sub.0 where C is the speed of light, f.sub.0 is
a reference frequency and f is the frequency of the pulses.
[0050] The systems and methods of this invention have various
applications. In general, the systems and methods of this invention
allow the monitoring of multiple degrees (e.g. six degrees) of
freedom of an object. For example, the systems and methods of this
invention can be used for structural assembly, real-time alignment
and feedback control, machine tool calibration, robotic position
control, position tracking, milling machine control, calibration,
parts assembly, dimensional inspection or the like.
[0051] Additionally, the systems and methods of this invention,
using a 6-D tracking system, lend themselves to use in the robotic
arts. For example, the 6-D laser tracking system can be
incorporated into a robot, that is, for example, capable of scaling
various objects such that, for example, precise measurements can be
taken of those objects and/or various functions performed at
specific locations on the object.
[0052] FIG. 1 is a schematic diagram illustrating an exemplary
multi-dimensional measuring system of the invention. Laser tracking
system 10 includes tracking unit 100 and target 150. Tracking unit
100 emits one or more lasers 110 that communicate with target 150
to determine the six dimensional measurements associated with
target 150. The six dimensional measurements are output on output
device 200. In particular, the six dimensions illustrated in FIG. 1
are pitch, yaw, and roll movements of target 150, the spherical,
and once converted Cartesian, coordinates of target 150 relative to
tracking unit 100, and the radial distance between target 150 and
tracking unit 100.
[0053] As discussed in Applicant's previous patents and patent
application referenced above, the pitch, yaw, and spherical
coordinate measurements can be based on various technologies. The
pitch and yaw measurements can be based on, for example, one or
more rotary encoders. The distance measurements can be based on,
for example, a pulsed laser configuration, an RTOF pulse, phase
and/or intensity modulation of the laser beam, or the like. These
various systems can provide absolute ranging of target 150. Target
150 is preferably an active target. Specifically, an absolute
distance measurement (ADM) technique can be used to determine an
approximate initial distance and then an interferometer based
technique can be used to refine the initial distance measurement.
The ADM technique is desirable because without it, two measurements
must be taken and reverse triangulation must be performed to
calculate the distance.
[0054] Tracking unit 100 and target 150 can be, for example,
motorized units that allow one or more portions of tracking unit
100 and target 150 to maintain a perpendicular orientation to
incoming laser beam 110 emitted from tracking unit 100. Tracking
unit 100 is the laser source. Thus, through a combination of rotary
encoders and motors that employ position signals from one or more
photodetectors, as discussed hereinafter, target 150 is capable of
remaining perpendicular to incoming laser beam 110. For example,
through the use of a gimbal type mount and corresponding position
motors, such as stepping motors, servo motors and/or encoders,
target 150 "tracks" tracking unit 100. Based upon the relationship
of target 150 to incoming laser 110, 6-D laser tracking system 10
is able to determine the orientation of target 150. Alternatively,
target 150 can be a passive device, for example, a hand-held device
such as a corner cube, for which a user would be responsible for
maintaining a line of sight between target 150 and tracking unit
100.
[0055] Preferably, tracking unit 100 is also capable of being
miniaturized by incorporating both the absolute distance
measurement and interferometer electronics in, for example, the
gimbaled portion of tracking unit 100. This provides various
exemplary advantages including reduced weight, reduced size,
minimization of external connections, quicker tracking speeds, and
the like.
[0056] Output device 200, connected to one or more of tracking unit
100 and target 150 via a wired or wireless link 5, outputs position
information associated with target 150. For example, output device
200 can be a computer, a feedback input for a position control
device, a display, a guidance system, or the like. In general,
output device 200 can be any device capable of outputting the
position information associated With target 150.
[0057] Additionally, one or more lasers 110 can be used to
communicate the position information about target 150 back to
tracking unit 100. For example, after an initial distance is
determined, the laser used for the absolute distance measurement
can be used for data communication and the interferometer based
laser used for the radial distance measurements. Alternatively, a
dedicated laser can be incorporated into system 10 that would allow
full time communication between target 150 and tracking unit
100.
[0058] FIG. 2 is a schematic diagram illustrating a roll
determination system of the invention. In particular, the system
includes a laser source (not shown) located in tracking unit 100,
polarized laser beam 210, polarizing beam splitter 220, first
photodetector 230, second photodetector 240, and roll determination
circuit 250. Roll determination circuit 250 can be, for example, a
differential amplifier. The laser source can be, for example, a
laser head. As shown in FIG. 2, polarizing beam splitter 220, first
photodetector 230, second photodetector 240, and roll determination
circuit 250 are members of target 150.
[0059] In operation, tracking unit 100 emits polarized laser beam
210 that is received by polarizing beam splitter 220. Polarizing
beam splitter 220 splits incoming beam 210 into two paths. A first
path is directed toward first photodetector 230 and a second path
of polarized laser beam 210 is directed toward second photodetector
240. When polarized laser beam 210 encounters polarizing beam
splitter 220, polarized laser beam 210 is split into horizontally
polarized component 214 and vertically polarized component 213 as a
result of the properties of beam splitter 220.
[0060] Horizontally polarized component 214 of beam 210 passes
through polarized beam splitter 220 to photodetector 240 that
generates an output signal corresponding to the intensity of
horizontally polarized component 214 of beam 210. Similarly,
vertically polarized component 213 of beam 210 is directed by beam
splitter 220 onto photodetector 230 that also produces a signal
corresponding to the intensity of vertically polarized component
213 of beam 210. The intensity measurements of photodetectors 230
and 240 can be connected to, for example, the positive and negative
inputs, respectively, of roll determination circuit 250, which
provides an output signal representative of the roll between
tracking unit 100 and target 150. Preferably, roll determination
circuit 250 is a high-gain differential amplifier.
[0061] As discussed above, polarized laser beam 210 is split into
two different polarized components based on the exact roll
orientation between tracking unit 100 and target 150. At a
45.degree. roll orientation, photodetectors 230 and 240 receive the
same intensity. However, as target 150 is rolled in either
direction, one of the detectors receives a greater intensity of
polarized laser beam 210 than the other. The difference between
these outputs is measured by, for example, roll determination
circuit 250, to provide an indication of the roll. This subtraction
operation of roll determination circuit 250 also advantageously
compensates for background and extraneous noise, such as that
produced by fluctuations in the beam intensity and/or background
light.
[0062] Specifically, variations in the beam output, as well as
other signal noise that maybe present, can be measured by both
photodetector 230 and photodetector 240. These variations can be
negated by the operation of roll determination circuit 250. This,
for example, increases the sensitivity and accuracy of the
system.
[0063] The signal representative of the roll can be output to, for
example, a computer (not shown) provided with software that is
capable of recording, analyzing or initiating further action based
on the roll measurement.
[0064] Alternatively, other techniques may be used for roll
determination. These techniques include, but are not limited to,
electronic levels, such as pendulum based techniques, conductive
fluid capillary tube techniques, liquid mercury reflective sensors,
or, in general, any technique that allows the roll of the target to
be determined.
[0065] FIG. 3 is a schematic diagram illustrating an exemplary
pitch, yaw, roll, and distance measuring system of the invention.
In particular, components of 6-D laser tracking system 30 include a
laser source present in tracking unit 100, polarized laser beam
310, beam splitter 320, corner cube 330, concentrator lens 340,
two-dimensional photodetector 350, first photodetector 230, second
photodetector 240, polarizing beam splitter 220, and roll
determination circuit 250.
[0066] In operation, the laser source in tracking unit 100 emits
polarized laser beam 310 that is split by beam splitter 320 into
three paths 324, 323, and 322 directed toward concentrator lens
340, corner cube 330, and polarizing beam splitter 220,
respectively.
[0067] Path 322 of beam 310 reflected by beam splitter 320 and
directed toward polarized beam splitter 220 is used to determine
the roll measurements, as discussed above. The combination of the
roll, the pitch, and the yaw measurements made by target 150, along
with the spherical coordinates associated with tracking unit 100,
allows system 30 to obtain the six-dimensional tracking of target
150.
[0068] Path 323 of polarized laser beam 310 passing directly
through beam splitter 320 is reflected by corner cube 330 and
returned to tracking unit 100. Tracking unit 100, as discussed in
Applicant's related patents referenced above, is then able to
determine the distance between target 150 and tracking unit 100.
However, it is to be appreciated that any method of determining an
absolute distance measurement can be used with equal success with
the systems and methods of this invention.
[0069] Path 324 directed towards concentrator lens 340 is focused
onto two-dimensional photodetector 350 from which the pitch and yaw
signals that drive the motors for target 150 are derived. In
particular, as target 150 moves relative to the laser source in
tracking unit 100, laser path 324 directed through concentrator
lens 340 moves relative to two-dimensional photodetector 350. This
movement can be detected and a corresponding signal representative
of the pitch and/or yaw measurement can be obtained. Then, as
discussed above, the pitch and/or yaw measurements can be used to
control one or more motors on target 150 to maintain the
perpendicular orientation of target 150 to tracking unit 100.
[0070] FIG. 14 is a two-dimensional schematic diagram showing
another exemplary embodiment of a target of the invention that
includes a retro-reflector. FIG. 15 is a three-dimensional
schematic diagram showing the exemplary embodiment of FIG. 14.
[0071] System 1400 of the invention includes tracking unit 100 and
target 1450. Tracking unit 100 is the source of laser beams that
are detectable by target 1450. Target 1450 includes retro-reflector
1420 and laser light sensor 1430. Laser light sensor 1430 can be,
for example, a photodetector, such as photosensor 240 described
above, or a charge coupled device (CCD) array sensor described
below. Amplifier/repeater 1440 can be associated with laser light
sensor 1430 to amplify analog signals or digital signals produced
by laser light sensor 1430.
[0072] A laser beam light from tracking unit 100 that go through
aperture 1422 of retro-reflector 1420 can be detected by laser
light sensor 1430. Retro-reflector 1420 can be a hollow
retro-reflector or a solid retro-reflector. Apex 1422 allows at
least part of laser beam 1410 to go through to fall or focus onto
laser light sensor 1430, which can be a photodetector or a CCD
array sensor.
[0073] Preferably, retro-reflector 1420 is a hollow retro-reflector
as shown in FIG. 16. Exemplary hollow retro-reflector 1600 shown in
FIG. 16 includes three mirrors 1610, 1620, and 1630 that are
positioned perpendicular to each other. A common extremity
associated with mirrors 1610, 1620, and 1630 forms apex 1601 of
hollow retro-reflector 1600. Aperture. 1602 is preferably a tiny
hole located at apex 1601 of hollow retro-reflector 1600. Aperture
1602 allows at least part of laser beam 1410 to go through to fall
or focus onto laser light sensor 1430, which can be a photodetector
or a CCD array sensor.
[0074] If a solid retro-reflector is used, a small flat surface
near the apex is polished to create a way to allow at least part of
laser beam 1410 to go through to fall or focus onto laser light
sensor 1430. As shown in FIG. 17, solid retro-reflector 1700
includes flat surface 1702 at apex 1701. Flat surface 1702 behaves
similarly to aperture 1602 described above.
[0075] Retro-reflector 1420 and laser light sensor 1430 are
configured to measure the pitch (see axis y-y in FIG. 15) and yaw
(see axis x-x in FIG. 15) orientations or movements of target 1450.
Vectors V.sub.y plus V.sub.x and distance D give angle position of
incoming laser beam 1410 to target 1450. Target 1450 can be
associated with a remote unit (e.g., robot 400, remote units 700,
800, and 1200 shown in FIGS. 4, 7, 8, and 12, respectively).
[0076] FIG. 14 schematically illustrate how a yaw movement
associated with target 1450 can be measured. When target 1450
indicates no yaw movement, laser beam light 1410 goes through
aperture 1422 and is detected by laser light sensor 1430 at an
origin or reference point 1432. However, as indicated by laser
paths 1413 and 1415, any yaw movement of target 1450 would result
in laser beam light 1410 to be detected by laser light sensor 1430
at locations other than reference point 1432, for example, at
points 1433 and 1435, for paths 1413 and 1415 of laser beam light
1410, respectively. Note that points 1433, 1432 and 1435 would be
along axis x-x shown in FIG. 15. Preferably, retro-reflector 1420
and laser light sensor 1430 are configured to detect a large range
of yaw movements. For example, retro-reflector 1420 and laser light
sensor 1430 can measure yaw movements up to at least about 30
degrees, depending on size and other factors.
[0077] Similarly, the pitch movement of target 1450 can be detected
and measured using retro-reflector 1420 and laser light sensor
1430. At a zero pitch movement, laser beam light 1410 goes through
aperture 1422 and is detected by laser light sensor 1430 at
reference point 1432. If there is a pitch movement, a different
part of laser light sensor 1430, either above or below reference
point 1432 in a direction perpendicular to the page, would detect
the laser beam light. Note that these points would be along axis
y-y shown in FIG. 15.
[0078] As discussed above, laser light sensor 1430 can be a
photodetector. In a different embodiment of the invention, a CCD
array sensor can be used as laser light sensor 1430. As known in
the art, a CCD array sensor can include multiple pixels arranged in
an array. Preferably, a CCD array sensor in accordance with the
invention includes about 1,000 by 1,000 pixels. Larger or smaller
number of pixels may also be used. Digital output from the CCD
array sensor can processed by a corresponding repeater 1440. The
CCD array sensor is used to detect one or both yaw and pitch
movements of target 1450. The use of CCD array sensor for detection
of light is known in the art, for example, in digital cameras.
Therefore, no further description is believed to be warranted
here.
[0079] Inclusion of retro-reflector 1420 and laser light sensor
1430 in target 1450 as described above provides several advantages.
For example, a remote unit (e.g., one of remote units 700, 800, and
1200) associated with retro-reflector 1420 can be more functional
in an upside-down orientation, which is otherwise not possible. In
addition, the use of retro-reflector 1420 allows a target and/or a
remote unit of the invention to be smaller in size and/or lighter
in weight.
[0080] FIG. 4 illustrates an exemplary remote unit of the
invention. Robot 400 includes a plurality of suction cup type
devices 410, drive mechanism 420, controller 430, accessory 440,
suction device 450, and a target. The target can be, for example,
one of target 150 and target 1450. Robot 400 also includes various
other components such as a power supply, battery, solar panels, or
the like that have been omitted for the sake of clarity and would
be readily apparent to those of ordinary skill in the art.
[0081] In operation, the combination of target 150 in conjunction
with robot 400 allows, for example, precise movement and location
tracking of robot 400. While a particular robotic active target is
discussed below, it is to be appreciated that in general the target
can be fixably attached to any object to allow monitoring of up to
six degrees of freedom of the object, or, alternatively, the target
can be attached to a movable device and the position of that device
monitored.
[0082] Suction cup type devices 410 are connected to suction device
450 via, for example, hoses (not shown) that enable robot 400 to
remain affixed to a surface. For example, controller 430, in
conjunction with suction device 450 and suction cup type devices
410 can cooperate with drive systems 420 such that robot 400 is
able to traverse a surface. For example, suction cup type devices
410 and drive mechanism 420 can cooperate such that sufficient
suction is applied to suction cup type devices 410 to keep robot
400 affixed to a surface, while still allowing the drive mechanism
420 to move the robot 400 over the surface. For example, drive
mechanism 420 can include four wheels, and associated drive and
suspension components (not shown). The wheels allow the traversal
of robot 400 over a surface while maintaining the rotational
orientation of robot 400 relative to tracking unit 100. However, in
general, while it is simpler to operate robot 400 such that the
rotational orientation remains constant relative to tracking unit
100, the system can be modified in conjunction with the use of the
polarized laser to account for any rotational movement that may
occur. Specifically, for example, the rotational movement of robot
400 can be algorithmically "backed-out" of the orientation
measurements based on the polarized laser to account for any
rotation of robot 400.
[0083] Furthermore, it should be appreciated that while robot 400
includes suction device 450 and suction cup type devices 410, any
device, or combination of devices, that are capable of movably
fixing robot 400 to a surface would work equally well with the
systems and methods of the invention. For example, a positive air
pressure system can be used to force robot 400 to be movably fixed
to the surface. For example, the positive air pressure system can
include an air blowing unit that blows air downwards when robot 400
is traversing under, rather than above, the surface. The downward
air movement keeps robot 400 movably fixed under the surface.
Additionally, depending on the surface type, a magnetic,
gravitational, resistive, or the like type of attachment system
could be employed.
[0084] Controller 430, which can, for example, be in wired or
wireless communication with a remote controller (not shown), allows
for navigation of robot 400 in cooperation with drive mechanism
420. For example, drive mechanism 420 can include a plurality of
electric motors connected to drive wheels, or the like.
[0085] Accessory 440, can be, for example, a marking device, a
tool, such as a drill, a painting attachment, a welding or cutting
device, or any other known or later developed device that needs
precise placement on a surface. The accessory can be activated, for
example, remotely in cooperation with controller 430. In addition,
accessory 440 can include a vacuum system.
[0086] Since accessory 440 is located on a known distance from
target 150, the exact position of accessory 440 is always known.
Thus, a user can position accessory 440 in an exact location such
that accessory 440 can perform an action at that location. For
example, a local effect sensor like a strip camera, a Moire fringe
patent sensor, or a touch probe can be attached to the end of
target 150. Tracking unit 110 combined with target 150 can provide
the orientation of the local sensor in a spatial relationship with
the part to be measured while the local sensor is measuring the
contours of a part, such as a car body, a building, a part in an
environmentally hazardous area, or the like.
[0087] FIG. 5 illustrates an exemplary schematic, cross-sectional
view of robot 400. In this illustration, robot 400 is shown to
include movable distance determining device 540. In addition to
position sensing equipment associated with target 150, movable
distance determining device 540 extends from the base of robot 400
to surface 510. Distance determining device 540 measures the exact
distance between target 150 and surface 510 such that the exact
location of the surface 510 relative to target 150 is always
known.
[0088] As illustrated in FIG. 5, suction cup type devices 410 are
located a fixed distance above surface 510 via spacers 530. For
example, spacers 530 can be a bearing, or other comparable device
that allows for suction cup type devices 410 to remain a fixed
distance above surface 510 while still allowing air 520 to create a
suction between robot 400 and surface 510.
[0089] Given the mobility of robot 400, it is foreseeable that
robot 400 may not always be in communication with tracking unit
100. In the event robot 400 loses line-of-sight with tracking unit
100, the 6-D laser tracking system can then enter a target
acquisition mode.
[0090] In the target acquisition mode, a user can, for example,
with a joystick, aim tracking unit 100 generally in the vicinity of
robot 400. Tracking unit 100 then commences a target acquisition
process in which tracking unit. 100 begins a spiral type pattern
that spirals outward to locate target 150. Upon acquisition of
target 150, communication between tracking unit 100 and target 150
is established and the six-dimensional measurements are again
available.
[0091] Alternatively, for example, target 150 can maintain
communication with tracking unit 100 via, for example, a radio
communication link, or other known or later developed system that
allows the tracking unit 100 to track the relative position of
target 150 regardless of whether line-of-sight is present. Thus,
when line-of-sight is reestablished, as discussed above, the
six-dimensional measurements are available.
[0092] FIG. 6 is a flowchart illustrating an exemplary method of
taking measurements according to the invention. In particular,
control begins in step S100 where communication between a tracking
unit (e.g., tracking unit 100) and a target (e.g., target 150) are
established. For example, for an interferometer based system, the
target can be placed at a known position to both establish
communication with the tracking unit as well as to initialize the
system. For an absolute distance measurement system the target is
placed in communication with the laser and an approximate radial
distance (R) obtained.
[0093] Next, in step S120, the target is placed at a first point to
be measured.
[0094] Then, in step S130, the pitch, yaw, roll, and spherical
coordinates are obtained.
[0095] In step S140, the spherical coordinates are converted to
Cartesian (x,y,z) coordinates, where x is the horizontal position,
y the in/out position, and z the up/down position of the
target.
[0096] Then, in step S150, the position measurements are
output.
[0097] Control then continues to step S160 in which a determination
is made on whether additional points should be measured. If so, the
process goes to step S170; otherwise, the process ends.
[0098] In step S170, the target is moved to a new point to be
measured. In an embodiment in which the target is coupled to a
remote unit such as a robot, the robot is commanded to move to the
new point. The process then return to step S130.
[0099] There may be instances, for example, where the point to be
measured is not in the line-of sight of the tracking unit, or,
alternatively, for example, the point to be measured is
inaccessible by the target. FIGS. 7-13 illustrate exemplary
embodiments in which a probe assembly is associated with the target
in a remote unit to take measurements at points that is otherwise
inaccessible by the target.
[0100] FIG. 7 is a schematic diagram illustrating an exemplary
multi-dimensional measuring system of the invention that includes
an exemplary tracking unit and an exemplary remote unit.
Multi-dimensional measuring system 70 includes tracking unit 100
and remote unit 700. Remote unit 700 includes target 150, probe
assembly 600. Probe assembly 600 includes probe stem 610, probe tip
620, and probe base 730. Remote unit 700 is configured to obtain
positional information of a point or location that is touchable by
probe tip 620, but which is not in the line of sight of tracking
unit 100.
[0101] In this embodiment, target 150, as described above, can make
pitch, yaw, and roll movements about origin 760, the position of
which can be determined because it is in the line of sight of
tracking unit 100. Probe 620 is configured to touch or come into
contact with a point or location that is not in the line of sight
of tracking unit. Probe tip 620 is connected to probe base 730 by
probe stem 610. In one embodiment, probe base 730 is fixed or
immovable with respect to target 150. In such embodiment, probe
base 730 itself cannot make any pitch, yaw, or roll movements.
However, probe tip 620 can move pivoting about probe base 730 along
circle 605, which forms a disc shape point cloud perpendicular to
the page. Thus, in additional to the previously described six
dimensions associated with target 150, the movement of probe tip
620 adds the seventh dimension, making system 70 a seven
dimensional system.
[0102] A point or location that is not in the line of sight of
tracking unit 100, but which is touchable by probe tip 620, can be
determined as follows.
[0103] First, probe stem 610 is locked in place relative to probe
base 730. Probe stem 610 can be locked in place using a number of
different methods. For example, probe stem 610 can be locked in
place with the use of a wing nut and associated locking teeth
640.
[0104] Second, target 150 is brought closer to seat 750 and probe
620 comes into contact with center 752 of seat 750. Center 752 of
seat 750 is a known location. For example, the position (x, y, z)
of center 752 relative to tracking unit 100 can be determined using
a system and method shown in FIGS. 19 and 20, which are described
below. Because origin 760 can be measured by tracking unit 100
directly, and center 752 of seat 750 has a known position, the
vector of point tip 620 relative to origin 760 is established.
[0105] Third, target 150 is moved to measure a point or location
that is touchable by probe tip 620. Using computer software or
other known methods, position information associated with the point
or location touched by probe tip 620 can be calculated base on the
position information of origin 760 and the vector of point 620
relative to origin 760.
[0106] In lieu of using seat 750 to determine the vector of point
620 relative to origin 760, one or more encoders coupled to probe
base 730 can be used.
[0107] FIG. 8 is a schematic diagram illustrating another exemplary
remote unit of the invention. Remote unit 800 shown in FIG. 8
includes probe assembly 600 that is configured to move along two
axes, which makes remote unit 800, when used with tracking unit
100, an eight-dimensional measuring system. In accordance with this
exemplary embodiment, in addition to target 150, probe assembly
600, remote unit 800 further includes encoders 720 and 740.
Optionally, remote unit 800 further includes handle assembly 700
(which includes trigger 710).
[0108] In this exemplary embodiment, yaw movements of probe base
730 is measured by encoder 720, and pitch movements of probe base
730 is measured by encode 740. Thus, in this embodiment, probe tip
620 can be moved about probe base 730 to establish a spherical
point cloud about probe base 730. The vector of probe tip 620
relative to origin 760 can be established using measurements taken
by encoders 720 and 740.
[0109] To measure a point or location touchable by probe tip 620,
the following steps can be used.
[0110] First, target 150 is brought near the point or location and
probe tip 620 is moved about probe base 730 so that probe tip can
come into contact with the point or location. Second, because
origin 760 is in the line of sight of tracking unit 100, the six
dimensions associated with target 150 can be obtained as described
above. Third, using information obtained by encoders 720 and 740,
which establishes the vector of probe tip 620 relative to origin
760, position information associated with the point or location can
be obtained. Preferably, the second and third steps can be
performed in a single step using by squeezing trigger 710.
[0111] FIG. 9 is a schematic diagram illustrating an exemplary
probe assembly of the invention. Exemplary point cloud 607, if
projected in three dimensions relative to probe base 730,
represents the distance d of probe tip 620 from an origin, such as
probe base 730.
[0112] FIG. 10 is a schematic diagram illustrating another
exemplary probe assembly of the invention. In this embodiment,
probe stem 610 has an "L" shape configuration rather than a
straight "I" shape configuration. However, in general, probe stem
610 can be in any shape and the user only need adjunct seat 750
such as to allow probe tip 620 to sit in seat 750 during
initialization to create the point cloud. As depicted in FIG. 10,
the "L" shape probe stem 610 enables probe tip 620 to touch a
bottom surface of an object, such as bottom surface 1052 of object
1050.
[0113] FIG. 11 is a schematic diagram illustrating another
exemplary probe assembly of the invention. Probe assembly 1100 and
tracking unit 100 constitute a nine-dimensional version of an
exemplary tracking system according to this invention. In
particular, in addition to the movements of probe stem 610
illustrated in FIGS. 7 and 8, probe stem 610 in FIG. 11 is capable
of extending in a longitudinal direction, i.e., telescoping, so
that distance d can be varied. With the aid of encoder 1000, which
can be, for example a glass-scale encoder, a linear scale encoder,
a magnescale encoder, or the like, the length of probe stem 610 can
be determined.
[0114] In operation, a user can either adjust the length or
orientations of probe stem 610 and perform initialization, with the
length of probe stem 610 remaining static during measurements, or,
in addition to the steps enumerated above, also vary the length of
probe stem 610 during initialization to create a semi-solid point
cloud (not shown) that represents the distance d of probe tip 620
from an origin relative to the rotational movement of probe base
730, the length of extension of probe stem 610, and the rotational
movement of probe tip 620 about probe base 730. The various
readings from the encoders 720, 740, and 1000 can then be stored to
be used for actual position determination during the measurement
process.
[0115] Then, during use, one or more of probe length, e.g.,
distance d (measured by encoder 1000), probe rotation in yaw
direction (measured by rotary encoder 720), and probe rotation in
pitch direction (measured by encoder 740) can be varied by the user
as appropriate to allow probe tip 620 to be placed on the object to
be measured. Furthermore, while probe tip 620 is illustrated herein
is a sphere, it is to be appreciated that the tip can be any shape,
such as a point, cup, or bearing that allows probe tip 620 to move
across an object, or the like. For example, as discussed
previously, a measurement can be taken instantaneously using
trigger 710 (see FIG. 8), or continuously, for example, while probe
tip 620 traverses an object.
[0116] FIGS. 12 and 13 are schematic diagrams illustrating
different views of an exemplary remote unit of the invention.
Remote unit 1200 includes target 150 that has been described above.
Target 150 includes beam splitter 1240 and a plurality of
photodetectors 1250. Remote unit 1200 further includes adjustable
probe assembly 1210, electronic level 1220, and handle 1230 Probe
assembly 1210 includes probe tip 1260.
[0117] The operation of remote unit 1200 involves a user
maintaining an orientation between remote unit 1200 and a tracking
unit (e.g., tracking unit 100 shown in FIG. 1). Measurements with
remote unit 1200 can be accomplished in a similar fashion to that
discussed in relation to remote units 700 and 800 above.
Specifically, an initialization is performed to determine the
position of probe tip 1260 in relation to remote unit 1200. The
initialization can occur after fixing of probe assembly 1210 in a
fixed position or, alternatively, by moving probe assembly 1210
through a plurality of positions and, for example, creating a point
cloud as discussed above. Alternatively, probe tip 1260 can be
placed at various positions on a known object, such as a sphere,
and initialization accomplished.
[0118] When a measurement associated with a location touched by
probe tip 1260 is to be taken, a trigger associated with handle
1230 is squeezed. Alternatively, probe tip 1260 can be configured
to be touch-sensitive. For example, in an exemplary implementation
of the invention, probe tip 1260 is associated with a touch sensor.
In the exemplary implementation, a measurement is taken by remote
unit 1200 whenever probe tip 1260 comes into contact with the
location. In this context, the contact is a physical contact.
[0119] In other implementations, the contact can be effected when
probe tip 1260 comes into close proximity with the location. Such
non-physical contact can be accomplished using, for example,
magnetic or infrared devices that are associated with probe tip
1260.
[0120] Remote unit 1200 can determine roll based on, for example an
electronic level technique or, for example, using the differential
amplifier technique discussed above. The electronic level technique
can be implemented using electronic level 1220.
[0121] FIG. 18 is a schematic diagram showing another exemplary
embodiment of a remote unit of the invention that includes an
optical measuring sensor. Remote unit 1800 includes optical
measuring sensor 1830. Optical measuring sensor 1830 can be used to
measure an area or a surface geometry. Preferably, optical
measuring sensor 1830 is located near a bottom portion of remote
unit 1800, as shown in FIG. 18. However, optical measuring sensor
1830 can be otherwise associated with remote unit 1800, including
near a top or a side portion of remote unit 1800.
[0122] FIG. 19 is a schematic diagram showing an exemplary system
for establishing the vector of a probe tip relative to an origin of
a target associated with the probe tip. System 1900 includes remote
unit 700 with origin 760 and probe tip 620 as described above.
Probe tip 620 can be, for example, a ruby sphere. System 1900
further includes magnetic puck 1910, spherical mounted
retro-reflector (SMR) 1920, and one or both dummy units 1930 and
1940.
[0123] Magnetic puck 1910 includes a plurality of supports 1912,
1914, and 1916. Magnetic puck 1910 further includes magnet 1918.
Supports 1912, 1914, and 1916 are configured to support one of SMR
1920, hemispherical dummy unit 1930, and spherical dummy unit 1940.
Preferably, each of SMR 1920 and dummy units 1930, 1940 are made of
magnetic stainless steel so that magnet 1918 of magnetic puck 1910
can secure it on supports 1912, 1914, and 1916. Preferably, magnet
1918 is disposed at a location among supports 1912, 1914, and
1916.
[0124] SMR 1920 includes retro-reflector 1924 that is housed within
body 1926 of SMR 1920. Retro-reflector 1924 can be a hollow
retro-reflector (e.g., similar to hollow retro-reflector 1600) or a
solid retro-reflector (e.g., similar to solid retro-reflector
1700). Body 1926 is preferably made of magnetic stainless steel.
SMR 1920 can have a range of diameters. Typical diameters of SMR
1920 are 0.5 inch, 0.75 inch, 1.0 inch, and so on. Retro-reflector
1924 includes apex 1922. Preferably, SMR 1920 is configured so that
apex 1922 is located at the center of SMR 1920.
[0125] Hemispherical dummy unit 1930 includes body 1936 and center
1932. Hemispherical dummy unit 1930 has a diameter that is same as
the diameter of SMR 1920 so that the location of center 1932
correspond with the location of apex 1922. Body 1936 is preferably
made of magnetic stainless steel.
[0126] Spherical dummy unit 1940 includes body 1946 and center
1942. Spherical dummy unit 1940 has a diameter that is same as the
diameter of SMR 1920 so that the location of center 1942 correspond
with the location of apex 1922. Body 1946 is preferably made of
magnetic stainless steel.
[0127] FIG. 20 is a flowchart illustrating an exemplary method of
establishing the vector of the probe tip depicted in FIG. 19.
[0128] In step S210, magnetic puck 1910 is fixed to a location,
e.g., the location of seat 750 shown in FIG. 7, Preferably,
magnetic puck 1910 is secured to the location so that placement or
removal of SMR 1920 or dummy units 1930, 1940 would not move
magnetic puck 1910.
[0129] In step S220, SMR 1920 is placed on magnetic puck 1910.
Preferably, SMR 1920 is secured to magnetic puck 1910 by magnet
1918 on supports 1912, 1914, and 1916.
[0130] In step S230, position information of apex 1922 can be
obtained by a tracking unit, e.g., tracking unit 100 shown in FIG.
7. In this manner, SMR 1920 behaves as a target in a conventional
three dimensional measurement system.
[0131] In step S240, SMR 1920 is replaced with one of dummy units
1930 and 1940 on magnetic puck 1910. For example, SMR 1920 is
removed and one of dummy units 1930 and 1940 is placed on magnetic
puck 1910, secured by magnet 1918 on supports 1912, 1914, and
1916.
[0132] In step S250, probe tip 620 is brought to touch the dummy
unit to establish the position information of the center of the
dummy unit in step S260.
[0133] If hemispheric dummy unit 1930 is used, probe tip 620
touches center 1932 of hemispheric dummy unit 1930. Because the
diameter of hemispheric dummy unit 1930 is same as the diameter of
SMR 1920, the position of center 1932 corresponds with the position
of apex 1922, which was obtained in step S230.
[0134] In step S260, the vector of probe tip 620 relative to origin
760 of remote unit 700 is established. This can be done because, as
explained above, origin 760 is in the line of sight of tracking
unit 100 and probe tip 620 touches a known location, which is
center 1932, the position established in step S230 by apex
1922.
[0135] If spherical dummy unit 1940 is used in step S240, probe tip
620 cannot touch center 1940 directly. However, the position of
center 1940 can be established by probe tip 620 touching four or
more points on body 1946 in step S250. Because the diameter of
spherical dummy unit 1940 is same as the diameter of SMR 1920, the
position of center 1942 corresponds with the position of apex 1922,
which was obtained in step S230. The vector of probe tip 620
relative to origin 760 can then be established in step S260.
[0136] In step S270, probe tip 620 can be used to take measurements
at various points and locations.
[0137] As illustrated in the figures and described above, the
multi-dimensional systems of the invention can be implemented
either on a single programmed general purpose computer, or a
separate programmed general purpose computer and associated laser
generating and detecting, motor and rotary encoder components.
However, various portions of the multi-dimensional laser tracking
system can also be implemented on a special purpose computer, a
programmed microprocessor or microcontroller and peripheral
integrated circuit element, an ASIC or other integrated circuit, a
digital signal processor, a hard-wired electronic or logic circuit
such as a discrete element circuit, a programmable logic device
such as a PLD, PLA, FPGA, PAL, or the like. In general, any device
capable of implementing a state machine that is in turn capable of
implementing the measurement techniques discussed herein and
illustrated in the drawings can be used to implement the
multi-dimensional laser tracking system according to this
invention.
[0138] Furthermore, the disclosed methods may be readily
implemented in software using object or object-oriented software
development environments that provide portable source code that can
be used on a variety of computer or workstation hardware platforms.
Alternatively, the disclosed multi-dimensional laser tracking
system may be implemented partially or fully in hardware using
standard logic circuits or VLSI design. Whether software or
hardware is used to implement the systems in accordance with this
invention is dependent on the speed and/or efficiency requirements
of the system, the particular function, and the particular software
and/or hardware systems or microprocessor or microcomputer systems
being utilized. The multi-dimensional laser tracking system and
methods illustrated herein, however, can be readily implemented in
hardware and/or software using any known or later-developed systems
or structures, devices and/or software by those of ordinary skill
in the applicable art from the functional description provided
herein and a general basic knowledge of the computer and optical
arts.
[0139] Moreover, the disclosed methods may be readily implemented
as software executed on a programmed general purpose computer, a
special purpose computer, a microprocessor, or the like. In these
instances, the methods and systems of this invention can be
implemented as a program embedded on a personal computer such as a
Java.RTM. or CGI script, as a resource residing on a server or
graphics workstation, as a routine embedded in a dedicated
multi-dimensional laser tracking system, or the like. The
multi-dimensional laser tracking system can also be implemented by
physically incorporating the system and method into a software
and/or hardware system, such as the hardware and software systems
of a multi-dimensional laser tracking system.
[0140] It is, therefore, apparent that there has been provided, in
accordance with the present invention, systems and methods for
multi-dimensional laser tracking. While this invention has been
described in conjunction with a number of exemplary embodiments, it
is evident that many alternatives, modifications and variations
would be or are apparent to those of ordinary skill in the
applicable arts. Accordingly, the invention is intended to embrace
all such alternatives, modifications, equivalents and variations
that are within the spirit and scope of this invention.
[0141] The foregoing disclosure of the preferred embodiments of the
present invention has been presented for purposes of illustration
and description. It is not intended to be exhaustive or to limit
the invention to the precise forms disclosed. Many variations and
modifications of the embodiments described herein will be apparent
to one of ordinary skill in the art in light of the above
disclosure. The scope of the invention is to be defined only by the
claims appended hereto, and by their equivalents.
[0142] Further, in describing representative embodiments of the
present invention, the specification may have presented the method
and/or process of the present invention as a particular sequence of
steps. However, to the extent that the method or process does not
rely on the particular order of steps set forth herein, the method
or process should not be limited to the particular sequence of
steps described. As one of ordinary skill in the art would
appreciate, other sequences of steps may be possible. Therefore,
the particular order of the steps set forth in the specification
should not be construed as limitations on the claims. In addition,
the claims directed to the method and/or process of the present
invention should not be limited to the performance of their steps
in the order written, and one skilled in the art can readily
appreciate that the sequences may be varied and still remain within
the spirit and scope of the present invention.
* * * * *