1||||ll|||||||lllllllllllll||ll|l||||Illlllllllllllllllllllllllllllllllllll
`
`USOO5751832A
`
`United States Patent
`
`[193
`
`[11] Patent Number:
`
`5,751,832
`
`Panter et al.
`
`[45] Date of Patent:
`
`May 12, 1998
`
`5,373,357
`5,379,104
`
`5392a!”
`5426500
`5,504,574
`
`12/1994 Hopkins et a1,
`1/1995
`
`........................ 356/121
`
`2/1995
`6/1995
`4/1996
`
`
`
`FOREIGN PATENT DOCUMENTS
`185800
`7/1986 European Pat. Ofi“.
`G01M 11/06
`M96356 12/1988 European Pat. Ofl.
`..... .. GOIM 11/O6
`1.360619
`7/1974 United K1l1gCl0[Il ........... GU23 27/00
`
`Primary Examiner—Andrew Johns
`""°”'€>’~ A8"’"’» 0’ F"”'"—Y°““8 & Basin RC-
`[57]
`ABSTRACT
`
`An apparatfls and m€th°<1 for aiming 5* Vchicle headlishfi 10
`a standard image pattern 1l1C1UClCS a frame movable relative
`to the vehicle. A housing carried on a vertically adjustable
`housing includes a lens focusing a headlight bea.m onto a
`reflective screen which reflects the beam image to a camera.
`A °°““'°1 °°mP‘““5 the dlgmlfid “M36 °“‘P“‘ “Om ‘he
`camera with a standard image pattern and generates a
`correlation factor based on the difference between the
`reflected image and a standard image. Based on the
`diiference. the control generates output signals to an adjust-
`ment device engagable with the headlight mounting frame to
`adjust the position of the mounting frame to reduce the
`.
`d‘fi°’°“°° t° Z°r°‘
`
`28 Claims, 9 Drawing Sheets
`
`1
`
`KOITO 1014
`
`[54] HEADLIGHT A]1\/IING APPARATUS
`
`[75]
`
`Inventors: Ronald L. Pantier. Flushing; John J.
`Taylor. Flint. both of Mich.
`
`[73] Assignees: Progressive Tool & Industries Co..
`Southfield; Panter Master Controls,
`Inc.. Mt. Morris. both of Mich.
`
`N0‘:
`
`SeP* 4» 1996
`[22] Filed‘
`[51]
`Int. Cl.‘ ..................................................... .. G06K 9/00
`[52] U.S. Cl.
`.............
`382/104; 382/291; 356/121
`[58] Field of Search ..
`...................... .. 382/104. 278.
`382/288. 291; 356/121; 348/95. 135; 364/424.034
`
`
`
`[55]
`
`References Cited
`
`U-S- PATENT DOCUMENTS
`10/1970 Hopkins et al.
`........................ 240/413
`3,532,433
`3,341,759 10/1974 Turner ..............
`355/121
`__ 356/121
`4,634,275
`1/1987 Yoshida et al.
`..
`4,679,935
`7/1987 Fukuda et al.
`356/121
`4,907,877
`3/1990 Fukuda et al.
`356/121
`4,948,249
`8/1990 Hopkins et al.
`355/121
`5,078,490
`1/1992 Oldweiler et al.
`356/121
`356/121
`5,164,785
`11/1992 Hoplcinsetal.
`356/121
`5,210,539
`5/1993 Kaya et a1.
`5,321,439
`6/1994 Rogers .............
`343/135
`5,331,393
`7/1994 Hopkins et a1.
`........................ 356/121
`
`
`
`1
`
`KOITO 1014
`
`

`
`U.S. Patent
`
`May 12, 1998
`
`Sheet 1 of 9
`
`5,751,832
`
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`U.S. Patent
`
`May 12, 1993
`
`Sheet 2 of 9
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`5,751,832
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`U.S. Patent
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`May 12, 1998
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`Sheet 4 of 9
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`5,751,832
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`U.S. Patent
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`May 12, 1998
`
`Sheet 6 of 9
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`5,751,832
`
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`
`U.S. Patent
`
`May 12, 1993
`
`Sheet 7 of 9
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`5,751,832
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`U.S. Patent
`
`May 12, 1998
`
`Sheet 3 of 9
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`5,751,832
`
`9
`
`

`
`U.S. Patent
`
`May 12, 1993
`
`Sheet 9 of 9
`
`5,751,832
`
`10
`
`10
`
`

`
`1
`HEADLIGHT AIMING APPARATUS
`
`BACKGROUND OF THE INVENTION
`
`1. Field of the Invention
`
`The present invention relates. in general. to vehicle head-
`light aiming apparatus and methods.
`2.Description of the Art
`Vehicle headlights project a light beam forward of a
`vehicle to illuminate the roadway for a driver. High beam
`and low beam headlights either in separate light bulbs or
`implemented by dual filaments and lens in a single bulb
`project different light patterns.
`Headlights must be aimed according to standards. such as
`an SAE standard in the United States and different but
`
`similar standards in Europe and Japan. Typically. a light
`beam is projected onto a target board set 25 feet in front of
`the vehicle. An ideal light beam pattern or image imprinted
`on the target board is manually compared with the light
`beam image or pattern from the vehicle and manual
`adjustments. as necessary. made to the headlight support
`structure to properly coincide the headlight beam pattern
`with the standard image pattern.
`Another method utilizes the reflection of a light beam
`from a vehicle headlight through a lens and olf of a screen
`to a camera which produces a digitized image of the
`reflected light beam. The focal length of the lens and the
`distance between the lens and the screen are optically
`equivalent to the 25 foot distance between the headlight and
`target board described above. The digitized image is then
`analyzed by an algorithm executed by a processor to locate
`the highest intensity pattern or “hot spot” which is consid-
`ered to be the main optical axis of the headlight. The
`headlight is adjusted. as necessary. to align the hot spot with
`the hot spot of a properly aligned headlight according to the
`various standards.
`
`Dilferent aiming algorithms are necessary since the inten-
`sity contours of diflerent style lamps varies by the particular
`market. Both left hand and right hand headlight algorithms
`are also needed. Typically. however. these algorithms are
`very sensitive to hardware noise and require additional
`processing to remove “aim bounce” which has the effect of
`reporting varying aimpoint values during static repeatability
`testing.
`Since all headlights including both low and high beam
`lights in each vehicle made in a manufacturing plant must be
`properly aimed. consideration must be taken as to the
`integration of the headlight aiming procedure in the typically
`high speed production line. Due to high production rates.
`vehicles have been directed to a plurality of individual
`headlight aiming stations. The multitude of stations adds
`expense to the aiming operation and may introduce vari-
`ability in the aiming results between the dilferent stations.
`Other aiming apparatus. which have been incorporated
`directly into the production line. must be moved into a
`position in front of each vehicle at the proper time. This has
`met with problems in repeatably aligning the headlight
`aiming apparatus with each vehicle.
`Thus. it would be desirable to provide a headlight aiming
`apparatus and method which utilizes an improved algorithm
`for greater aiming accuracy. It would also be desirable to
`provide a headlight aiming apparatus and method which is
`usable with a plurality of different headlight image patterns.
`It would also be desirable to provide a headlight aiming
`apparatus which can be easily integrated into a vehicle
`assembly line.
`
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`5,751,832
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`2
`SUNIMARY OF THE INVENTION
`
`The present invention is an aiming apparatus suitable for
`aiming a vehicle headlight mounted in an adjustable frame
`on a vehicle to a standard or reference aiming pattern.
`The headlight aiming apparatus of the present invention
`includes a housing having a focusing lens mounted in one
`side. A screen is mounted in the housing and spaced from the
`lens at a prescribed distance to focus a headlight pattern
`image striking the lens on the screen where it is reflected to
`an image sensing means mounted in the housing and spaced
`from the screen. The image sensing means senses the
`reflected headlight image.
`Means are coupled to or formed as a part of the image
`sensing means for converting the sensed image to digital
`image representations which are output
`to a processor
`means. A memory means is disposed in data communication
`with the processor means and stores standard image patterns
`of properly aimed headlights. The processor means is
`responsive to the output of the image converting means and
`the standard headlight aiming patterns stored in the memory
`means for determining differences between a reflected head-
`light pattern sensed and output from the converting means
`and a reference pattern stored in memory. In response to any
`determined dilferenoes. the processor means generates cor-
`rection signals which are supplied to an adjusting means.
`such as a power driven screwdriver engagable with the
`headlight aiming frame on the vehicle. The adjusting means
`is responsive to the correction signals for adjusting the
`position of the headlight mounting frame to bring the
`headlight pattern in substantial alignment with standard
`headlight reference patterns.
`Preferably. the processing means forms a sample window
`of pixels in the digitized image and the model image and
`multiplies the grayscale intensity values of identical pixels
`in each image. The products are summed to generate a
`correlation value for the sample window. Since several
`sample windows are then formed. each olfset from other
`sample windows and the product and summation steps are
`repeated to locate a sample window with the highest corre-
`lation value. The center of this sample window is determined
`by the difference in the X and Y axis from the center of the
`model image. In response to the difference. the processor
`means generates a signal to drive the adjusting means in a
`direction to reduce the difference to zero.
`
`In a preferred embodiment. a frame is disposed trans-
`versely to a longitudinal axis of a vehicle. Means are
`provided for movably mounting the housing on the frame for
`movement between a home position and an aiming position.
`Optionally. means are mounted on the frame for calibrat-
`ing the home position of the housing each time the housing
`moves to the home position. Preferably.
`the calibrating
`means comprises a correctly aimed headlight or a laser
`mounted on the frame generating a light beam coinciding
`with the hot spot of a properly aimed headlight.
`The memory means also stores X and Y axis position
`signals for the moving means. Means. coordinating with the
`particular vehicle. are used to select the X and Y positions
`of the moving means to repeatably position the housing in
`the proper aiming position for each headlight on each
`vehicle or vehicles.
`
`Means are also provided for varying the speed of rotation
`of the adjusting means in proportion to the magnitude of the
`difierence between the reflected headlight pattern and the
`stored reference pattern on a pixel-by-pixel basis.
`Preferably. pulse width modulated drive means. responsive
`
`11
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`3
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`4
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`5.751.832
`
`to the output signal from the processor means. controls to the
`adjusting means to vary the frequency of electrical power
`supplied to the adjusting means.
`The present invention also defines a method for aiming a
`vehicle headlight to a standard or reference aiming image
`pattern. The method comprises the steps of:
`focusing a light beam from a vehicle headlight onto a
`reflective surface; sensing the intensity of the reflected
`light beam from the surface on a pixel-by-pixel basis in
`a matrix of pixels; forming a sample window matrix of
`pixels. multiplying the grayscale value of each pixel in
`the sample window with the value of the corresponding
`pixel in the model image. summing all of the products
`for each sample window to form a correlation value.
`forming consecutive sample windows offset from each
`other. forming a correlation value for each sample
`window determining the center along X and Y axes of
`the sample window using the highest correlation value;
`determining difierence between the center of the
`sample window with the highest correlation and the
`center of the model image in at least one axis; and
`activating an adjustment means engagable with a head-
`light mounting frame to adjust the headlight position in
`at least one axis to reduce the dilference to zero.
`The headlight aiming apparatus and method of the present
`invention provides a highly accurate aiming process which
`eliminates certain of the problems when encountered with
`previously devised vehicle headlight aiming apparatus. The
`present apparatus is capable of storing many different head-
`light aiming patterns or images thereby enabling the appa-
`ratus to be used in multiple applications or in a single
`production line for many difierent style vehicles. The
`present apparatus is also easily integrated into a vehicle
`production line without requiring multiple aiming stations.
`
`BRIEF DESCRIPTION OF THE DRAWING
`
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`
`The various features. advantages and other uses of the
`present invention will become more apparent by referring to
`the following detailed description and drawing in which:
`FIG. 1 is a front elevational view of a headlight aiming
`apparatus constructed in accordance of the teachings of the
`present invention;
`FIG. 2 is a left side elevational view of the apparatus
`shown in FIG. 2.
`
`FIG. 3 is a plan view of the apparatus shown in FIG. 1;
`FIG. 4 is a partially broken away. perspective View of the
`camera housing shown in FIGS. 1 and 2;
`FIG. 5 is a block diagram of the control means employed
`with the apparatus shown in the preceding Figures;
`FIG. 6 is a side elevational view of a headlight mounting
`and adjustment structure;
`FIG. '7 is a pictorial representation of the headlight aiming
`process employed in the apparatus of the present invention;
`FIG. 8 is a perspective View of the gantry shown in FIG.
`1; but with additional features;
`FIG. 9 is a perspective View showing the camera posi-
`tioning means mounted on the gantry shown in FIG. 1; and
`FIG. 10 is an exploded. perspective view of another
`embodiment of the camera housing of the present invention.
`
`DESCRIPTION OF THE PREFERRED
`EMBODIMENTS
`
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`Referring now to the drawing. and to FIGS. 1-3 in
`particular.
`there is depicted a vehicle headlight aiming
`
`12
`
`apparatus 10. The apparatus 10 includes means for moving
`a reflected light beam detecting means or camera into
`position in front of a vehicle headlight. Preferably.
`the
`moving means includes a gantry 12 which is positioned
`transverse to the longitudinal axis of a vehicle located
`adjacent to the gantry 12. The gantry 12 includes a lower
`frame formed of a plurality of vertically extending legs 14
`which are securely mounted at one end to a floor surface.
`An upper frame is formed of four vertically extending
`legs 16 each of which is joined at one end to one of the legs
`14 of the lower frame. Four generally horizontally
`extending. interconnected tubular members. each denoted
`by reference number 18 are fixed to the vertical legs 16.
`Angular braces 20 extend between each vertical leg 16 and
`an adjacent horizontal leg 18. As shown in FIG. 2. a pair of
`horizontally extending slide rails 22 are mounted on two of
`the horizontal tubular members 18 of the upper frame.
`As shown in FIGS. 1 and 2. a movable mounting rack
`denoted by reference number 30 is movably mounted for
`horizontal movement along the tubular members 18. The
`movable rack 30 includes an upper frame structure formed
`of four interconnected tubular members generally connected
`in a square or rectangular shape as shown in FIG. 3. Four.
`elongated. vertically extending legs 32 are connected at
`upper ends to the tubular members 31 and depend downward
`therefrom.
`
`A vertically extending slide member 34 is slidably
`mounted on each of the vertical legs 32 as shown in FIG. 2.
`A vertical moving means is coupled to the four slide
`members 34 for vertically adjusting the position of the four
`slide members 34 and the camera housing attached to the
`vertical slide members 34 as described hereafter. A hollow
`tubular member 36 is centrally located between and con-
`nected to the vertical slide members 34 by braces 38. Aball
`nut 42 is mounted at one end of the hollow tubular member
`36 and threadingly receives a ball screw 42 therethrough.
`The ball screw 42 extends from the ball nut 42 to a
`bi-directional output shaft of an electric drive motor 44
`mounted on the upper frame of the movable rack 30.
`Energization of the drive motor 44. as described hereafter.
`will cause rotation of the ball screw 42 in one of two
`directions. Rotation of the ball screw 42 results in vertical
`movement of the tubular member 32 via the ball nut 40 in
`an upward or downward direction depending on the direc-
`tion of rotation of the ball screw 42 to thereby adjust the
`vertical position of the tubular member 36 and the vertical
`slide members 34 connected thereto.
`As shown in FIGS. 1-3. a horizontal drive means is
`mounted to the gantry 12 and connected to the upper frame
`of the movable rack 30. The horizontal drive means hori-
`zontally translates the movable rack 30 along two of the
`horizontal members 18 of the upper frame of the gantry 12.
`As shown in FIG. 2. slide rail engaging members 46, each
`having a longitudinal through bore. are spaced apart on
`opposite sides of the upper frame of the movable rack 30 and
`slidably receive the slide rails 22 attached to two of the
`upper frame members 18 of the gantry 12.
`The horizontal drive means includes an electric drive
`motor 24 mounted at one end of the upper frame of the
`gantry 12. The drive motor 24 has a bi-directionally rotat-
`able output shaft which engages a gear reducer 25. The gear
`reducer 25 drives a sprocket which engages a toothed drive
`belt 26 formed in a continuous loop. The opposite end of the
`drive belt 26 passes around a roller mounted on the upper
`frame. A plate 28 is fixed to the drive belt 26 and to the upper
`frame of the movable rack 30 to couple horizontal move-
`ment of the drive belt 26 to horizontal movement of the rack
`30.
`
`12
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`5.751.832
`
`5
`As shown in FIGS. 1-2. a frame 50 formed of intercon-
`nected tubular members is connected by brackets to one
`each the vertical slide members 34 and to the tubular
`
`member 36. A housing 52 is fixedly connected to the frame
`members 50 by brackets for vertical movement with move-
`ment of the vertical slide members 34 via the drive motor 44.
`the ball screw 42. the ball nut 40 and the centrally located
`tubular member 36 as described above.
`
`The gantry 12. depicted as an alternate. but preferred
`embodiment in FIG. 8.
`is substantially identical to that
`described and shown above in FIGS. 1-3; but includes
`several modifications. A pair of safety light reflectors 180
`and a corresponding pair of light emitters 182 are mounted
`on the legs 14 of the gantry 12 in aligned pairs to provide a
`safety curtain or envelope about the movement path of the
`camera housing 52 along the gantry 12.
`A vehicle presence detector 184 is mounted on the gantry
`12. such as on one of the horizontal members 18 as shown
`
`in FIG. 8. The vehicle presence detector 184. by example
`only. is in the form a light emitter which is aimed at a
`suitable light reflector mounted on the floor or other st:ruc—
`ture in front of the gantry 12. Passage of a vehicle through
`a light beam extending between the light emitter 184 and the
`associated light reflector will cause the light emitter 184 to
`provide a signal to the controller indicating that a vehicle has
`approached the headlight aiming apparatus 10.
`Various overtravel limit switches are mounted on the
`
`gantry 12 for detecting the position of the camera moving
`means. Limit switches 186 and 188 are mounted at opposite
`ends of one of the horizontal members 18 for detecting
`extreme lateral positions of the camera moving means. A
`shock absorber 190 mounted on the gantry 12 to provide a
`cushion for return of the camera moving means to a home
`position.
`A control panel 192 is mounted on the side of one pair of
`vertical legs 14 of the gantry 12.
`A top rail 258 is mounted on each horizontal leg 18 and
`supports the circular cross-section slide rail 22. An addi-
`tional rail 197 is mounted by legs to one horizontal leg 18
`and extends above the leg 18 to support a gear rack 199.
`A preferred embodiment of the camera moving means is
`shown in greater detail in FIG. 9. A plate or carriage 194
`carries a pair of aligned pillow blocks 195 on each of two
`opposed sides which engage the tubular rods 24 mounted on
`the two horizontal rails attached to the top of the horizontal
`legs 18 of the gantry 12.
`An enclosure or junction box 196 is mounted on the
`carriage 194 and housing electrical connections to the vari-
`ous electrical components mounted on the carriage 194 as
`described hereafter.
`
`The horizontal drive motor 24 is mounted on the carriage
`194 and has an output shaft connected to the gear reducer 25.
`An encoder 200 is coupled to the gear reducer 25 to provide
`horizontal position output signals or pulses. A pinion gear
`201 is driven by the gear reducer 25 and engages the gear
`rack 199 mounted on the rail 197 aflixed to one horizontal
`
`leg 18 of the gantry 12. Bi—directional rotation of the pinion
`gear 201 along the gear rack 199 drives the carriage 194
`horizontally along the rails 22.
`The output shaft of the vertical drive motor 44 is coupled
`to a threaded shaft or jack screw 42 which extends through
`a centrally located aperture in the carriage 194. An encoder
`198 is coupled to the shaft 42 to provide position infom1a-
`tion relating to the linear position of the shaft 42 upon
`bi-directional energization of the vertical drive motor 44 as
`described above.
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`Four apertures. each denoted by reference number 202.
`are located near the corners of the carriage 194. A guide rod
`204 is extensible through each aperture 202 as shown in
`FIGS. 9 and 10. The guide rods 204 are fixedly mounted on
`the housing 52 and extend through hollow guide cylinders or
`sleeves 206 fixedly mounted on and extending from the
`bottom surface of the carriage 194 and aligned with one
`aperture 202 in the carriage 194. In this manner. rotation of
`the threaded shaft 42 by the vertical drive motor 44 causes
`the threaded shaft 42 to screw into or out of the jack cylinder
`43 mounted on the housing 52 which results in vertical
`movement of the housing 52.
`As shown in FIG. 9. a detector 208. such as a proximity
`switch. is mounted on the carriage 194 adjacent one guide
`rod 204. The detector 208 is positioned to detect the absence
`of the end of the adjacent guide rod 204 for an indication of
`vertical downward overlravel of the housing 52.
`Another detector. such as a limit switch 209. is mounted
`
`on the carriage 194 and positioned to detect an end cap on
`the end of rod 204 when the rod 204 and attached housing
`52 is at a vertical home position.
`As shown in greater detail in one embodiment in FIG. 4.
`the housing 52 comprises a generally four-sided enclosure
`having a pair of spaced side walls 54. a bottom wall 56. a top
`wall 58. and a rear or back wall 60. A door or front cover 62
`is pivotally connected. such as by a hinge. to one edge of one
`of the side walls 54 and is loclringly engagable with the
`opposed side wall 54 to close the interior of the housing 52;
`while at the same time allowing access to the components
`mounted within the interior of the housing 52. An aperture
`61 is formed in the door 62 and receives a transparent cover
`plate 63. A bottom slide plate 64 is disposed within the
`housing 52 and slidingly overlays the bottom wall 56 of the
`housing 52.
`A pair of generally U-shaped channel members 66 are
`mounted at one end of the bottom slide plate 64 and extend
`vertically therefrom. Although only one is shown in FIG. 4.
`a pair of adjustable support assemblies 74 fixedly connect
`each channel member 66 to one edge of the bottom slide
`plate 64. The channel members 66 support a focusing lens
`68. such as a flat FRESNEL lens. Resilient pads 70 and a
`spacer 72 are mounted in each channel member 66 for
`resiliently supporting the lens 68 in the channel members 66.
`SAE headlight aiming tests require that the headlight
`beam be imaged on a surface spaced 25 feet from the vehicle
`headlight. The focal length of the lens 68 is chosen so that
`a headlight beam image is formed on the back wall 60 of the
`housing 52 which is comparable to an image formed 25 feet
`from the vehicle headlight.
`An image sensing means or camera 80 is secured to the
`bottom slide plate 64 via a mount 82. The camera 80 may be
`any type of camera for sensing the image reflected off of the
`flat black back wall 60 of the housing 52. Preferably. the
`camera 80 is a CCD type camera which has a plurality of
`light sensor cells arranged in a 512x480 pixel matrix. By
`example only. the camera 80 may be a Panasonic camera.
`model number WV-BP500. A six millimeter F12 lens is
`mounted on the camera 80.
`
`FIG. 10 depicts an alternate embodiment of the camera
`housing 52. The housing 52 is substantially identical to the
`housing 52 described above and shown in FIG. 4 in that it
`includes a pair of spaced side walls 54. the top wall 58. a
`bottom wall. and a rear or back wall. A door or front cover
`62. shown in FIG. 4. is pivotally connected to one end of one
`of the side walls 54 and is lockingly engagable with the
`housing 52 by means of suitable latches mounted on the
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`front door or cover. The front door includes an aperture 61
`which receives a transparent cover plate 63 as shown in FIG.
`4.
`
`In the embodiment shown in FIGS. 8. 9 and 10. an
`external mounting plate 254 is mounted on the top wall 58
`of the housing and receives mounting pads at the ends of the
`guide rods 204 and jack cylinder 43. An internal mounting
`plate 256 is mounted on an inner surface of the top wall 58
`of the housing 52.
`The camera slide tray 210 is slidably mounted in the
`housing 52 by a two-part slide including slide element
`mounted on the slide tray 210 and a mating element. not
`shown. mounted on the housing 52. The slide tray 210
`includes a back wall 212. a pair of spaced side walls 214. and
`a bottom wall 216. The camera slide tray 210 is sized to
`slidably fit within the housing 52 as shown in FIG. 10.
`The camera 80 is mounted on the bottom wall 216 of the
`slide tray 210. A screen or reflective surface 218 is adjust-
`ably mounted within the slide tray 210. Adjustable mounting
`means includes a plurality of threaded rods 220 which
`fixedly extend from the back wall 212 through apertures in
`the screen 218 and bores in a plurality of mounting blocks
`22. Athreaded fastener. such as a nut 224. is mounted about
`each rod 220 and threaded into engagement with the front
`surface of the screen 218 to fix the position of the screen 218
`relative to the camera 80. The four threaded rods 220. the
`fasteners 224 and the mounting blocks 222 enable the
`vertical and horizontal angular position of the screen 218 to
`be adjusted relative to the camera 80 by extension and
`retraction of the rods 220 relative to the back wall 212.
`The focusing lens 68 is part of a lens package or assembly
`230. As described above. the focusing lens 68 is preferably
`a flat FRESNEL lens. The lens 68 is disposed between two
`protective.
`transparent sheets 232. which are preferably
`formed of a strong material. such as LEXAN. A frame 234
`formed of angle iron has a plurality of apertures spaced
`along the top and bottom edges for receiving threaded
`fasteners 236 which extend through the apertures in the
`frame 234. and each of the protective sheets 232 and the lens
`68. for holding the various elements of the lens assembly
`230 in an assembled relationship within the frame 234.
`Lens frame mounting and adjustment means are provided
`for mounting the lens assembly 230 in the slide tray 210;
`while providing venical and horizontal adjustment of the
`lens 68 relative to the screen 218. The adjustment means
`includes elongated fasteners 238. such as hex head bolts.
`which extend through apertures in the vertical side legs of
`the frame 234 and the sides of each of the protective plates
`232 and the lens 68. Abiasing means. such as a compression
`spring 240. is disposed about the threaded shank of each
`fastener 238 between the innermost protective sheet 232 and
`a pair of lens mounting blocks 242. The lens mounting
`blocks 242 are fixedly secured. such as by welding or
`fasteners. to the inner surfaces of the side walls 214 of the
`slide tray 210 and include a pair of spaced bores which
`slidably receive the shanks of the threaded fasteners 238.
`Suitable nuts. not shown. are mounted about the shanks of
`the fasteners 238 after the shanks pass through the lens
`mounting blocks 242. In this manner. vertical and horizontal
`adjustments in the position of the lens 68 may be attained by
`rotating the hex head of any of the fasteners 238.
`Also mounted on the vertical tubular members 32 shown
`in FIG. 1 is a control panel 86 having a touch screen LCD
`display 88 and a plurality of manual pushbuttons or selector
`switches 90 for providing various inputs to the control
`means described hereafter. The display 88 displays various
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`menus or status information to an operator as well as
`providing touch input selections.
`Also mounted on one of the vertical legs 14 of the gantry
`12 is a calibration means for calibrating the housing 52 after
`each aiming operation. The calibration means includes a
`light source. such as a vehicle headlight 92. which is
`attached by a mounting bracket 94 to one of the vertical legs
`14 of the gantry 12. Additional details concerning the
`calibration features of the present
`invention will be
`described hereafter.
`
`Alternately. as shown in FIG. 8. the calibration means is
`formed of a laser mounted in a housing 250 attached to a
`frame extending from one of the vertical legs 14 of the
`gantry 12. Any suitable laser may be used. such as a
`Metzrologic laser. for example. The laser is aimed through an
`aperture 252 in the housing 250 and is aligned with the lens
`68 in the camera housing 52 when the camera housing 52 is
`at the calibration position.
`As shown in FIG. 2. a screwdriver mounting frame
`structure 96 is aflixed to one of the horizontal
`tubular
`members 18 of the gantry frame. The frame structure 96
`extends along the length of the gantry 12 and supports one
`or two cable reels 98. A cable 100 extends from each cable
`reel 98 and is connected to an electric motor driven screw-
`driver 102 which has a rotatable bit 104 mounted therein.
`The screwdriver 102 may be any conventional power
`screwdriver. such as one sold by DeSoutter.
`Only one screwdriver 102 is shown in FIG. 2. However.
`it will be understood that two screwdrivers 102 and 103. as
`shown in FIGS. 6 and 8. are typically mounted via separate
`cables 100 and reels 98 to the frame 96 and are slidingly
`movable along the frame 96 to adjust a vehicle headlight in
`both X and Y axes.
`The screwdriver 102 or screwdriver 103 has a
`bi-directionally rotatable output shaft. with the polarity of
`the voltage applied to the drive motor of the screwdriver 102
`and 103 determining the direction of rotation of the output
`shaft and the bit 104 connected thereto.
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`Referring now to FIG. 5. there is depicted a control means
`mounted separate from the gantry 12 which controls the
`operation of vehicle headlight aiming apparatus 10.
`The control means includes a controller. such as a
`microprocessor. mini computer. etc.. having a central pro-
`cessing unit (CPU) 110 which executes a control program
`stored in a memory 112. By example only. the CPU 110 is
`a 66 MHZ 80486 processor. A keyboard 114 is connected to
`the CPU 110 for inputting various information to the CPU
`110. A display 116 is also connected to the CPU 110 for
`displaying various output data.
`A digital signal processor 118 is also input to the CPU 110
`and. also. controls the display 116 for displaying the digi-
`tized image output from the camera 80. By example. the
`digital signal processor 118 is an IM-LC processor made by
`Matrox. Dorval. Quebec. Canada and acts as a frame grabber
`for the output of the camera 80.
`Although the CPU 110 is capable of directly controlling
`the operation of the screwdrivers 102 and 103 as well as the
`X and Y drive motors 24 and 44.
`in an exemplary
`embodiment. a programmable logic controller or PLC 120 is
`connected in data communication with the CPU 110. By
`example only. the PLC may be an Allen Bradley PDC model
`5/30 which is connected to the CPU 110 by a conventional
`data highway or bus utilizing Allen Bradley data commu-
`nication protocol. The outputs of the control panel 86; i.e..
`signals from a mode selector switch. start and stop
`pushbuttons. or other operator input. are input to the PLC
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`120. The PLC 120 is response to various inputs executes a
`stored control program to activate various outputs as
`described hereafter.
`
`Further inputs to the PLC 120 include signals 122 and 124
`which are respectively output from the horizontal encoder
`200 connected to the X axis drive motor 24 and the vertical
`encoder 198 connected to the Y axis drive motor 44. Any
`conventional encoder may be employed which generates a
`pulse for each predetermined amount of rotation of the
`motor