US007241034B2
`
`(12) United States Patent
`Smith et al.
`
`(10) Patent N0.:
`(45) Date of Patent:
`
`US 7,241,034 B2
`Jul. 10, 2007
`
`(54) AUTOMATIC DIRECTIONAL CONTROL
`SYSTEM FOR VEHICLE HEADLIGHTS
`
`4,066,886 A
`4,162,424 A
`4,186,428 A
`
`1/1978 Martin ..................... .. 362/465
`7/1979 Zillgitt et a1.
`362/467
`l/l980 Deverrewaere
`362/466
`
`
`
`
`
`, , i 4,225,902 A
`
`
`
`
`
`
`
`‘113,015?’ erg v1s ....... .. 9/1980 Ishikawa et a1. ..
`
`318/696
`
`
`
`(75) Inventors: James E. Smith, Berkey, OH (US); ég?ggg B‘ McDonald’ Perrysburg’
`
`_
`.
`(73) Asslgn?’Z Dana Corporal”, Toledo’ OH (Us)
`
`( * ) Notice:
`
`Subject to any disclaimer, the term of this
`patent is extended or adjusted under 35
`USC‘ 1540’) by 0 days‘
`
`1/1982 Claude et a1. ............ .. 362/466
`4,310,172 A
`4,549,277 A 10/1985 Brunson et a1.
`4,583,152 A
`4/1986 Kawai et a1. .......... .. 280/6158
`4,768,135 A
`8/1988 Kr t hm t l. ........ .. 362/40
`6 SC
`er 6 a
`(Continued)
`FOREIGN PATENT DOCUMENTS
`
`(21) Appl. N0.: 10/285,312
`
`(22) Filed:
`
`Oct. 31, 2002
`
`EP
`
`0306611
`
`3/1989
`
`(Continued)
`
`(65)
`
`.
`.
`.
`Pnor Pubhcatlon Data
`US 2003/0107898 A1
`Jun. 12, 2003
`
`Primary ExamineriAli Alavi
`(74) Attorney, Agent, or FirmiMacMillan, Sobanski &
`Todd, LLC
`
`Related US. Application Data
`
`(57)
`
`ABSTRACT
`
`(60) Provisional aPPlication NO‘ _60/369’447’ ?led on Apr‘
`2’ 2002’ provlslonal aPPPCaUOH N9‘ 6Q/356’703’ ?led
`on Feb‘ 13’ 2002’ provlslonal apphcanon NO‘ 60/335’
`409’ ?led on Oct‘ 31’ 2001'
`I t Cl
`3116b
`/00
`B 6 01% 22/00
`
`51
`(
`)
`
`2006 01
`(2006'01)
`_
`(
`'
`)
`(52) US. Cl. ....... ...... .., ..................... .. 362/465, 701/49
`(58) Field of Classi?cation Search ................ .. 362/37,
`_
`_
`362/4654166; 315/82; 701/ 49
`See aPPhCaUOn ?le for Complete Search hlstory-
`-
`References Cited
`
`(56)
`
`U.S. PATENT DOCUMENTS
`
`3,634,677 A
`
`l/l972 Stuttgart et a1. .......... .. 362/467
`
`3,939,339 A
`
`2/1976 Alphen . . . . . . . . . . .
`
`. . . .. 362/467
`
`3,953,726 A
`4,024,388 A
`
`362/465
`4/1976 Scarritt, Sr. ..
`5/1977 Skoif ....................... .. 362/467
`
`A structure and method for operating a directional control
`system for vehicle headlights that is capable of altering the
`directional aiming angles of the headlights to account for
`changes in the operating conditions of the vehicle. One or
`more operating condition sensors may be provided that
`generate signals that are representative of a condition of the
`vehicle, such as road speed, steering angle, pitch, suspension
`height, rate of change of road speed, rate of change of
`Steering angle, rate ofchange ofpitcha and rate of Change of
`Suspension height of the Vehicle_ A Controller is responsive
`to the sensor signal for generating an output signal. An
`actuator is adapted to be connected to the headlight to effect
`movement thereof in accordance With the out ut si
`al. The
`p
`gn
`controller can include a table that relates values of sensed
`operating condition to values of the output signal. The
`controller is responsive to the sensor signal for looking up
`the output signal in the table.
`
`5 Claims, 7 Drawing Sheets
`
`UP/DOWN
`ACTUATOR
`
`POSITION
`FEEDBACK
`SENSOR
`
`POSITION
`FEEDBACK
`SENSOR
`
`INPUT/OUTPUT
`DEVICE
`
`CONDITION
`SENSOR
`
`CONDITION
`SENSOR
`
`15
`
`LEFT/RIGHT
`ACTUATOR
`
`HEADLIGHT
`DIRECTIONAL
`CONTROLLER
`
`SL Corp. Exhibit 1001
`
`

`
`US 7,241,034 B2
`Page 2
`
`US. PATENT DOCUMENTS
`
`4,791,343 A 12/1988 Ahrendt .................... .. 362/348
`4,833,573 A
`5/1989 Miyauchi er a1- -
`-- 362/466
`4,868,720 A
`9/1989 Miyauchi er a1- -
`362/466
`4,868,721 A
`9/1989 Soardo ----------- --
`362/466
`4,870,545 A
`9/1989 Hamnaka er a1- -
`315/82
`4,891,559 A
`1/1990 Matsumoto et a1. .
`356/121
`4,907,877 A
`3/1990 Fukuda er a1- ----- --
`318/603
`4908560 A
`3/1990 Shibata er a1
`318/603
`4,916,587 A
`4/1990 Hirose et a1.
`362/460
`4,943,893 A
`7/1990 Shibata er a1
`---- -- 362/37
`4,948,249 A
`8/1990 Hopkins 9t a1~ --
`356/121
`5,060,120 A 10/1991 Kobayashi et al.
`362/465
`5,099,400 A
`3/1992 Lee ---------------- --
`362/37
`5,158,352 A 10/1992 Ikegami er a1
`362/359
`5,164,785 A 11/1992 Hopkins er a1
`356/121
`5,181,429 A
`1/1993 S1eber ......... ..
`74/8942
`5,193,894 A
`3/1993 Lietar et a1. .... ..
`362/466
`5,331,393 A
`7/1994 Hopkins et a1. ..
`356/121
`5,373,357 A 12/1994 Hopkins et a1. ..
`.. 356/121
`5,392,111 A
`2/1995 Murata et a1.
`356/121
`5,404,278 A
`4/1995 Shibata eta1~ -
`362/464
`5,426,571 A
`6/1995 Jones ....... ..
`362/466
`5428512 A
`6/1995 Mouzas
`362/466
`5,485,265 A
`1/1996 Hopkins ...... ..
`356/121
`5,526,242 A
`6/1996 Takahashi 613.1.
`362/466
`5,550,717 A
`8/1996 Liao
`. 362/467
`5,633,710 A
`5/1997 Kuniira ..................... .. 362/464
`5,660,454 A
`8/1997 Mon et a1.
`.
`5,707,129 A
`1/1998 Kobayash1 ..
`.
`5,751,832 A
`5/1998 Panter et a1.
`5,779,342 A
`7/1998 Kluge ...................... .. 362/507
`
`7/1998 Bitar et a1. ............... .. 340/468
`5,781,105 A
`7/1998
`. 362/459
`5,785,405 A
`2/1999 Speak et a1‘ ________________ __ 362/37
`5,868,488 A
`3/1999 Okuchi 61211. ............ .. 340/468
`5,877,680 A
`4/1999 Zillgitt ..... ..
`.340/468
`5,896,011 A
`5/1999 Hayami et a1. .......... .. 307/10.8
`5,907,196 A
`6/1999 GOtOh ....................... .. 362/37
`5,909,949 A *
`7/1999 panter et al‘
`356/121
`5920386 A
`8/1999 Hege ........................ .. 362/459
`5,938,319 A
`5,977,678 A 11/1999 Miller et a1. .............. .. 310/103
`6,010,237 A
`1/2000 Gotou
`_ 362/460
`6,049,749 A *
`4/2000 Kobayashi ................. .. 701/49
`6,097,156 A
`8/2000 Diep ......................... .. 315/82
`6,118,113 A
`9/2000 Hibbard et al
`250/205
`6,142,655 A 11/2000 Zillgitt et a1. ............. .. 362/466
`6,144,159 A 11/2000 Lopez @1211. ................ .. 315/82
`6,176,590 B1
`1/2001 Prevost 61211.
`.. 362/37
`6,183,118 B1
`2/200l Toda et al‘ N
`362/465
`6,193,398 B1 >1<
`20001 Okuchi et a1‘ “
`362/466
`6,227,691 B1
`5/2001 Hogrefe et al
`362/539
`6,231,216 B1
`5/2001 Frasch
`_ 362/464
`6,234,654 B1
`5/2001 Okuchi et a‘
`362/466
`6,281,632 B1
`8/2001 Stain 61211.
`.. 315/82
`6,293,686 B1
`9/2001 Hayami et a1‘ _
`362/465
`6,305,823 Bl* 10/2001 Toda 61211. ............... .. 362/276
`2001/0019225 A1
`9/2001 Toda et a1‘
`
`EP
`
`EP
`GB
`
`FOREIGN PATENT DOCUMENTS
`1142757
`100001
`
`1275555
`2340925
`
`1/2003
`30000
`
`* cited by examiner
`
`

`
`U.S. Patent
`
`Jul. 10, 2007
`
`Sheet 1 0f 7
`
`US 7,241,034 B2
`
`10
`
`\ 11 \
`
`12 —\
`UP/DOWN
`ACTUATOR
`A
`
`POSITION
`FEEDBACK
`SENSOR
`
`18
`
`19
`
`POSITION
`FEEDBACK 4
`SENSOR
`
`LEFT/RIGHT
`ACTUATOR
`/
`A
`
`13
`
`f 14
`
`‘
`
`HEADLIGHT
`
`~ DIRECTIONAL
`CONTROLLER
`
`17
`
`15
`
`-
`
`INPUT/OUTPUT 4—j
`DEVICE
`
`A
`
`A
`
`/
`
`CONDITION
`SENSOR
`
`CONDITION
`SENSOR
`
`16 —/
`
`FIG. 1
`
`

`
`U.S. Patent
`
`Jul. 10, 2007
`
`Sheet 2 0f 7
`
`US 7,241,034 B2
`
`ENTER CALIBRATION
`MODE
`
`I
`
`MANUALLY OPERATE
`ACTUATORS TO AIM
`HEADLIGHT IN
`REFERENCE ORIENTATION
`
`/“— 2 l
`
`20
`/
`
`22
`
`/
`
`FIG. 2
`
`y
`STORE POSITION IN
`HEADLIGHT DIRECTIONAL /— 23
`CONTROLLER AS
`REFERENCE POSITION
`
`

`
`U.S. Patent
`
`Jul. 10, 2007
`
`Sheet 3 0f 7
`
`US 7,241,034 B2
`
`SELECT ADJUSTMENT
`CONTROL ALGORITHM
`
`30
`
`GENERATE TABLE OF
`CONDITION VS.
`ADJUSTMENT CONTROL
`VALUES
`
`l
`
`l
`
`STORE TABLE IN
`HEADLIGHT DIRECTIONAL
`CONTROLLER
`
`/——32
`
`FIG. 3
`
`

`
`U.S. Patent
`
`Jul. 10, 2007
`
`Sheet 4 0f 7
`
`US 7,241,034 B2
`
`40
`
`SENSED CONDITION
`(STEERING ANGLE)
`VALUES
`
`UP/DOWN
`ADJUSTMENT
`FACTORS
`
`LEFT/RIGHT
`ADJUSTMENT
`FACTORS
`
`+5O
`+4°
`+3°
`
`0°
`-1°
`-2°
`—3°
`-4°
`-5°
`—6°
`
`-2.50°
`-2.00°
`-1.50°
`
`0.00°
`-O.50°
`-l.OO°
`-l.50°
`-2.00°
`—2.50°
`-3.00°
`
`+3.75°
`+3.00°
`+2.25°
`
`000°
`-0.75°
`-1.50°
`-2.25°
`—3.00°
`-3.75°
`-4.50°
`
`FIG. 4
`
`

`
`U.S. Patent
`
`Jul. 10, 2007
`
`Sheet 5 0r 7
`
`US 7,241,034 B2
`
`READ VALUE OF
`CONDITION SENSOR
`
`L
`
`V51 /
`
`50
`
`52
`
`33
`
`IS CONDITION
`SENSOR VALUE
`IN TABLE?
`
`YES I LOOKUP ADJUSTMENT
`FACTORS TN TABLE FOR
`SENSED CONDITION
`SENSOR VALUE
`
`54
`
`\ COMPARE ADJUSTMENT
`FACTORS WITH CURR‘ENT
`P SITIO
`HEADLIGHT 0'
`N
`
`LOOKUP ADJUSTMENT
`7
`FACTORS IN TABLE FOR
`ADJACENT CONDITION
`SENSOR VALUES
`
`5
`8
`
`\ INTERPOLATE
`ADJUSTNLENT FACTOR
`
`MAGNTTUDE OF
`ADJUSTMENT
`GREATER THAN
`THRESHOLD?
`
`56
`
`ENERGIZE HEADLIGHT
`ACTUATORS
`
`FIG. 5
`
`

`
`U.S. Patent
`
`Jul. 10, 2007
`
`Sheet 6 0f 7
`
`US 7,241,034 B2
`
`READ FIRST VALUE OF
`CONDITION SENSOR
`
`60
`
`l
`
`READ SECOND VALUE OF
`CONDITION SENSOR
`
`l
`
`CALCULATE RATE OF
`CHANGE OF SENSED
`CONDITION
`
`i
`
`ENERGIZE HEADLIGHT
`ACTUATORS
`
`FIG. 6
`
`

`
`U.S. Patent
`
`Jul. 10, 2007
`
`Sheet 7 0r 7
`
`US 7,241,034 B2
`
`f“ /
`
`70
`
`READ FIRST VALUE OF
`CONDITION SENSOR
`
`I
`
`READ SECOND VALUE OF /
`CONDITION SENSOR
`
`72
`
`l
`
`CALCULATE RATE OF
`CHANGE OF SENSED
`CONDITION
`
`1S RATE OF
`CHANGE LESS
`THAN
`THRESHOLD?
`
`/—" 3
`7
`
`74
`
`NO
`
`/~ 75
`
`ENERGIZE HEADLIGHT
`ACTUATORS
`
`FIG. 7
`
`

`
`US 7,241,034 B2
`
`1
`AUTOMATIC DIRECTIONAL CONTROL
`SYSTEM FOR VEHICLE HEADLIGHTS
`
`CROSS REFERENCE TO RELATED
`APPLICATIONS
`
`This application claims the bene?t of US. Provisional
`Application Nos. 60/335,409, ?led Oct. 31, 2001; 60/356,
`703, ?led Feb. 13, 2002; and 60/369,447, ?led Apr. 2, 2002,
`the disclosures of Which are incorporated herein by refer
`ence.
`
`BACKGROUND OF THE INVENTION
`
`This invention relates in general to headlights that are
`provided on vehicles for illuminating dark road surfaces or
`other areas in the path of movement. In particular, this
`invention relates to an automatic directional control system
`for such vehicle headlights.
`Virtually all land vehicles, and many other types of
`vehicles (such as boats and airplanes, for example), are
`provided With one or more headlights that are adapted to
`illuminate a portion of a dark road surface or other area in
`the path of movement of the vehicle to facilitate safe travel
`thereon. Typically, each headlight is mounted on or near the
`front end of the vehicle and is oriented in such a manner that
`a beam of light is projected forWardly therefrom. The angle
`at Which the beam of light projects from the headlight can,
`for example, be characterized in a variety of Ways, including
`(1) up and doWn relative to a horizontal reference position
`or plane and (2) left and right relative to a vertical reference
`position or plane. Such directional aiming angles are usually
`set at the time of assembly of the headlight into the vehicle
`so as to illuminate a predetermined portion of the road
`surface or other area in the path of movement of the vehicle.
`In the past, these headlights have been mounted on the
`vehicle in ?xed positions relative thereto such that the beams
`of light are projected therefrom at predetermined directional
`aiming angles relative to the vehicle. Although such ?xed
`aiming angle headlight systems have and continue to func
`tion adequately, they cannot alter the directional aiming
`angles of the headlights to account for changes in the
`operating conditions of the vehicle. For example, if the
`speed of the vehicle is increased, it Would be desirable to
`adjust the aiming angle of the headlights upWardly such that
`an area that is someWhat farther in front of the vehicle is
`more brightly illuminated. On the other hand, if the speed of
`the vehicle is decreased, it Would be desirable to adjust the
`aiming angle of the headlights doWnWardly such that an area
`that is someWhat closer in front of the vehicle is more
`brightly illuminated. Similarly, if the vehicle turns a corner,
`it Would be desirable to adjust the aiming angle of the
`headlights either toWard the left or toWard the right (depend
`ing on the direction of the turn) such that an area that is
`someWhat lateral to the front of the vehicle is more brightly
`illuminated.
`To accomplish this, it is knoWn to provide a directional
`control system for vehicle headlights that is capable of
`automatically altering the directional aiming angles of the
`headlights to account for changes in the operating conditions
`of the vehicle. A variety of such automatic directional
`control systems for vehicle headlights are knoWn in the art.
`HoWever, such knoWn automatic headlight directional con
`trol systems have been found to be de?cient for various
`reasons. Thus, it Would be desirable to provide an improved
`structure for an automatic headlight directional control sys
`tem that addresses such de?ciencies.
`
`20
`
`25
`
`30
`
`35
`
`40
`
`45
`
`50
`
`55
`
`60
`
`65
`
`2
`SUMMARY OF THE INVENTION
`
`This invention relates to an improved structure and
`method for operating a directional control system for vehicle
`headlights that is capable of automatically altering the
`directional aiming angles of the headlights to account for
`changes in the operating conditions of the vehicle. One or
`more operating condition sensors may be provided that
`generate signals that are representative of an operating
`condition of the vehicle, such as road speed, steering angle,
`pitch, suspension height, rate of change of road speed, rate
`of change of steering angle, rate of change of pitch, and rate
`of change of suspension height of the vehicle. A controller
`is responsive to the sensor signal for generating an output
`signal. An actuator is adapted to be connected to the head
`light to effect movement thereof in accordance With the
`output signal. The controller can include a table that relates
`values of sensed operating condition to values of the output
`signal. The controller is responsive to the sensor signal for
`looking up the output signal in the table.
`Various objects and advantages of this invention Will
`become apparent to those skilled in the art from the folloW
`ing detailed description of the preferred embodiments, When
`read in light of the accompanying draWings.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`FIG. 1 is a block diagram of an automatic directional
`control system for a vehicle headlight in accordance With
`this invention.
`FIG. 2 is a How chart of an algorithm for calibrating the
`automatic directional control system illustrated in FIG. 1 so
`as to de?ne an initial reference position for the headlight
`from Which the headlight directional controller can imple
`ment directional angle adjustments.
`FIG. 3 is a How chart of an algorithm for generating a
`table that relates one or more sensed vehicle operating
`condition values to one or more headlight directional angle
`adjustment factors and for storing such table in the headlight
`directional controller illustrated in FIG. 1.
`FIG. 4 is an example of a table that can be generated and
`stored in the headlight directional controller in accordance
`With the table generating algorithm illustrated in FIG. 3.
`FIG. 5 is a How chart of an algorithm for operating the
`headlight directional controller illustrated in FIG. 1 to auto
`matically implement directional angle adjustments in accor
`dance With sensed condition values.
`FIG. 6 is a How chart of an algorithm for operating the
`headlight directional controller illustrated in FIG. 1 to auto
`matically implement directional angle adjustments in accor
`dance With the rate of change of one or more of the sensed
`condition values.
`FIG. 7 is a How chart of an algorithm for operating the
`headlight directional controller illustrated in FIG. 1 to auto
`matically implement directional angle adjustments, but only
`When the rate of change of one or more of the sensed
`condition values is less than (or greater than) a predeter
`mined value.
`
`DETAILED DESCRIPTION OF THE
`PREFERRED EMBODIMENTS
`
`Referring noW to the draWings, there is illustrated in FIG.
`1 an automatic directional control system, indicated gener
`ally at 10, for a vehicle headlight 11 in accordance With this
`invention. The illustrated headlight 11 is, of itself, conven
`tional in the art and is intended to be representative of any
`
`

`
`US 7,241,034 B2
`
`3
`device that can be supported on any type of vehicle for the
`purpose of illuminating any area, such as an area in the path
`of movement of the vehicle. The headlight 11 is typically
`mounted on or near the front end of a vehicle (not shoWn)
`and is oriented in such a manner that a beam of light is
`projected therefrom. In a manner that is Well knoWn in the
`art, the headlight 11 is adapted to illuminate a portion of a
`dark road surface or other area in the path of movement of
`the vehicle to facilitate safe travel thereon.
`The headlight 11 is adjustably mounted on the vehicle
`such that the directional orientation at Which the beam of
`light projects therefrom can be adjusted relative to the
`vehicle. Any desired mounting structure can be provided to
`accomplish this. Typically, the headlight 11 is mounted on
`the vehicle such that the angle at Which the beam of light
`projects therefrom can be adjusted both (1) up and doWn
`relative to a horiZontal reference position or plane and (2)
`left and right relative to a vertical reference position or
`plane. Although this invention Will be described and illus
`trated in the context of a headlight that is adjustable in both
`the up/doWn direction and the left/right direction, it Will be
`appreciated that this invention may be practiced With any
`headlight 11 that is adjustable in any single direction or
`multiple directions of movement, Whether up/doWn, left/
`right, or any other direction.
`To e?fect movement of the illustrated headlight 11 relative
`to the vehicle, an up/doWn actuator 12 and a left/right
`actuator 13 are provided. The actuators 12 and 13 are
`conventional in the art and may, for example, be embodied
`as servo motors, step motors, or any other electronically
`controlled mechanical actuators. It has been found to be
`desirable to use microstepping motors for the actuators 12
`and 13. Such microstepping motors are knoWn in the art and
`consist of conventional step motors that have appropriate
`hardWare (i.e., driver integrated circuits) and softWare that
`alloW the step motors to be operated in fractional step
`increments. The use of such microstepping motors has been
`found to be desirable because they can effect movements of
`the headlights in a someWhat faster, smoother, and quieter
`manner than conventional step motors, and further permit
`more precise positioning of the headlights 11. In the illus
`trated embodiment, the up/doWn actuator 12 is mechanically
`connected to the headlight 11 such that the headlight 11 can
`be selectively adjusted up and doWn relative to a horizontal
`reference position or plane. Similarly, the illustrated left/
`right actuator 13 is mechanically connected to the headlight
`11 such that the headlight 11 can be selectively adjusted left
`and right relative to a vertical reference position or plane.
`A headlight directional controller 14 is provided for
`controlling the operations of the up/doWn actuator 12 and
`the left/right actuator 13 and, therefore, the angle at Which
`the beam of light projects from the headlight 11 relative to
`the vehicle. The headlight directional controller 14 can be
`embodied as any control system, such as a microprocessor
`or programmable electronic controller, that is responsive to
`one or more sensed operating conditions of the vehicle for
`selectively operating the up/doWn actuator 12 and the left/
`right actuator 13. To accomplish this, the automatic direc
`tional control system 10 can include, for example, a pair of
`condition sensors 15 and 16 that are connected to the
`headlight directional controller 14. The condition sensors 15
`and 16 are conventional in the art and are responsive to
`respective sensed operating conditions of the vehicle for
`generating electrical signals to the headlight directional
`controller 14. HoWever, if desired, only a single one of the
`condition sensors 15 and 16 need be provided. Alternatively,
`additional condition sensors (not shoWn) may be provided if
`
`20
`
`25
`
`30
`
`35
`
`40
`
`45
`
`50
`
`55
`
`60
`
`65
`
`4
`desired to generate electrical signals that are representative
`of any other operating conditions of the vehicle. A conven
`tional input/output device 17 is connected to (or can be
`connected to) the headlight directional controller 14 for
`facilitating communication thereWith in the manner
`described beloW.
`If desired, a ?rst position feedback sensor 18 may be
`provided for the up/doWn actuator 12, and a second position
`feedback sensor 19 may be provided for the left/right
`actuator 13. The position feedback sensors 18 and 19 are
`conventional in the art and are adapted to generate respec
`tive electrical signals that are representative of the actual
`up/doWn and left/right positions of the headlight 11. Thus,
`the ?rst position feedback sensor 18 is responsive to the
`actual up/doWn position of the headlight 11 (as determined
`by a portion of the up/doWn actuator 12, for example) for
`generating an electrical signal to the headlight directional
`controller 14 that is representative thereof. Similarly, the
`second position feedback sensor 19 is responsive to the
`actual left/right position of the headlight 11 (as determined
`by a portion of the left/right actuator 13, for example) for
`generating an electrical signal to the headlight directional
`controller 14 that is representative thereof. The position
`feedback sensors 18 and 19 can be embodied as any con
`ventional sensor structures, such as Hall effect sensors, that
`are responsive to movements of the headlight 11 (or to the
`movements of the respective actuators 12 and 13 that are
`connected to move the headlight 11) for generating such
`signals.
`Alternatively, the position feedback sensors 18 and 19 can
`be embodied as respective devices that generate electrical
`signals Whenever the headlight 11 has achieved respective
`predetermined up/doWn or left/right positions. This can be
`accomplished, for example, using a conventional optical
`interrupter (not shoWn) for each of the actuators 12 and 13.
`Each of the optical interrupters includes a ?ag or other
`component that is mounted on or connected to the headlight
`11 for movement thereWith. Each of the optical interrupters
`further includes an optical source and sensor assembly. As
`the headlight 11 is moved by the actuators 12 and 13, the ?ag
`moves thereWith relative to the optical source and sensor
`assembly betWeen a ?rst position, Wherein the ?ag permits
`light emitted from the source from reaching the sensor, and
`a second position, Wherein the ?ag prevents light emitted
`from the source from reaching the sensor. When the ?ag is
`in the ?rst position relative to the optical source and sensor
`assembly, the sensor is permitted to receive light emitted
`from the source. As a result, a ?rst signal is generated from
`the optical source and sensor assembly to the headlight
`directional controller 14. Conversely, When the ?ag is in the
`second position relative to the optical source and sensor
`assembly, the sensor is not permitted to receive light emitted
`from the source. As a result, a second signal is generated
`from the optical source and sensor assembly to the headlight
`directional controller 14. Thus, the edge of the ?ag de?nes
`a transition betWeen the ?rst and second positions of the ?ag
`relative to the optical source and sensor assembly and,
`therefore, de?nes a predetermined up/doWn or left/right
`position of the headlight 11. The nature of the signal
`generated from the optical source and sensor assembly to the
`headlight directional controller 14 (i.e., the ?rst signal or the
`second signal) can also be used to determine on Which side
`of the predetermined position (the left side or the right side,
`for example) that the headlight 11 is positioned. The purpose
`for such position feedback sensors 18 and 19 Will be
`discussed beloW.
`
`

`
`US 7,241,034 B2
`
`5
`FIG. 2 is a How chart of an algorithm, indicated generally
`at 20, for calibrating the automatic directional control sys
`tem illustrated in FIG. 1 so as to de?ne an initial reference
`position or positions for the headlight 11 from Which the
`headlight directional controller 14 can implement direc
`tional angle adjustments. As mentioned above, the headlight
`11 is mounted on the vehicle such that the angle at Which the
`beam of light projects therefrom can be adjusted both up and
`doWn relative to a horizontal reference position or plane and
`left and right relative to a vertical reference position or
`plane. To insure accurate positioning of the headlight 11, it
`is desirable that a reference position or positions be initially
`established by the headlight directional controller 14. Sub
`sequent directional angle adjustments can be made by the
`headlight directional controller 14 from the pre-established
`reference position or positions established by this calibration
`algorithm 20.
`To accomplish this, the calibration algorithm 20 has a ?rst
`step 21 Wherein the headlight directional controller 14 is
`caused to enter a calibration mode of operation. In the
`calibration mode of operation, the headlight directional
`controller 14 is responsive to input signals from the input/
`output device 17 (or from another source, if desired) for
`causing manual operation of the up/doWn actuator 12 and
`the left/right actuator 13. Thus, While the headlight direc
`tional controller 14 is in the calibration mode of operation,
`an operator of the input/output device 17 can manually e?fect
`either up/doWn movement of the headlight 11, left/right
`movement of the headlight 11, or both, as desired.
`In a second step 22 of the calibration algorithm 20, the
`up/doWn actuator 12 and the left/right actuator 13 are
`manually operated to aim the headlight 11 in a predeter
`mined reference orientation. This can be accomplished by
`use of the input/output device 17 that, as mentioned above,
`is connected to (or can be connected to) the headlight
`directional controller 14. Traditionally, the aiming of a
`headlight 11 has been accomplished by parking the vehicle
`on a surface near a Wall or other vertical structure, providing
`a reference target at a predetermined location on the Wall or
`other structure, and mechanically adjusting the mounting
`structure of the headlight 11 such that the center of the beam
`therefrom is projected at the reference target. In this inven
`tion, the vehicle is parked on a surface near a Wall or other
`vertical structure, and a reference target is provided at a
`predetermined location on the Wall or other structure, as
`described above. Next, in accordance With the second step
`22 of this calibration algorithm 20, the input/output device
`17 is operated to generate electrical signals to the headlight
`directional controller 14. In response to such electrical
`signals, the headlight directional controller 14 operates the
`up/doWn actuator 12 and the left/right actuator 13 to move
`the headlight 11 such that center of the beam projecting
`therefrom is aimed at the reference target. When the beam
`from the headlight 11 is so aimed, then the headlight 11 is
`determined to be oriented in the initial reference position
`from Which the headlight directional controller 14 can
`subsequently implement directional angle adjustments.
`In a third step 23 of the calibration algorithm 20, once this
`initial reference position for the headlight 11 has been
`achieved, such position is stored in the headlight directional
`controller 14 as the predetermined initial reference position.
`This can be accomplished by means of the position feedback
`sensors 18 and 19. As discussed above, the position feed
`back sensors 18 and 19 are adapted to generate respective
`electrical signals that are representative of the actual
`up/doWn and left/right positions of the headlight 11 or of the
`predetermined positions for the headlight. Thus, the ?rst
`
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`position feedback sensor 18 is responsive to the actual
`up/doWn position of the headlight 11 (as determined by the
`up/doWn actuator 12, for example) for generating an elec
`trical signal to the headlight directional controller 14 that is
`representative thereof. Similarly, the second position feed
`back sensor 19 is responsive to the actual left/right position
`of the headlight 11 (as determined by the left/right actuator
`13, for example) for generating an electrical signal to the
`headlight directional controller 14 that is representative
`thereof. Accordingly, the third step 23 of the calibration
`algorithm 20 can be performed by causing the headlight
`directional controller 14 to read the signals from the position
`feedback sensors 18 and 19 and store the current up/doWn
`and left/right positions of the headlight 11 as the initial
`reference positions from Which the headlight directional
`controller 14 can subsequently implement directional angle
`adjustments.
`The current position of the headlight 11 is preferably
`stored in the non-volatile memory of the headlight direc
`tional controller 14 for reference during normal operation of
`the automatic directional control system 10 described beloW.
`Thus, When the automatic directional control system 10 is
`initially activated (such as When the electrical system of the
`vehicle is initially turned on), the headlight directional
`controller 14 can position the headlight 11 at or near the
`calibrated position utiliZing the signals comparing the cur
`rent position of the headlight 11 (as determined by the
`signals generated by the position feedback sensors 18 and
`19) With the predetermined reference position determined by
`the calibration algorithm 20.
`FIG. 3 is a How chart of an algorithm, indicated generally
`at 30, for generating a table that relates the sensed condition
`values from the condition sensors 15 and 16 to the headlight
`directional angle adjustment factors that Will be imple
`mented by the headlight directional controller 14, and fur
`ther for storing such table in the headlight directional
`controller 14 illustrated in FIG. 1. As used herein, the term
`“table” is intended to be representative of any collection or
`association of data that relates one or more of the sensed
`condition values to one or more of the headlight directional
`angle adjustment factors. The table of data can be generated,
`stored, and expressed in any desired format. For example,
`this table of data can be generated, stored, and expressed in
`a conventional spreadsheet format, such as shoWn in FIG. 4,
`Which Will be discussed in detail beloW.
`In a ?rst step 31 of the table generating algorithm 30, an
`adjustment control algorithm is selected. The adjustment
`control algorithm can be, generally speaking, any desired
`relationship that relates one or more operating conditions of
`the vehicle to one or more angular orientations of the
`headlight 11. A variety of such relationships are knoWn in
`the art, and this invention is not intended to be limited to any
`particular relationship. Typically, such relationships Will be
`expressed in terms of a mathematical equation or similar
`relationship that can be readily processed using a micropro
`cessor or similar electronic computing apparatus, such as the
`above-described headlight directional controller 14. The
`particular adjustment control algorithm that is selected may,
`if desired, vary from vehicle to vehicle in accordance With
`a variety of factors, including relative siZe and performance
`characteristics of the vehicle or any other desired condition.
`As mentioned above, a plurality of operating conditions
`may be sensed by the condition sensors 15 and 16 and
`provided to the headlight directional controller 14 for use
`With the adjustment control mechanism. For example, the
`condition sensors 15 and 16 may generate electrical signals
`to the headlight directional controller 14 that are represen
`
`

`
`US 7,241,034 B2
`
`7
`tative of the road speed, the steering angle, and the pitch of
`the vehicle (Which can, for example, be determined by
`sensing the front and rear suspension heights of the vehicle
`or by a pitch or level sensor). Additionally, the time deriva
`tive of these operating conditions (i.e., the rate of change of
`the road speed, steering angle, and pitch of the vehicle) can
`be sensed or calculated. However, any other operating
`condition or conditions of the vehicle may be sensed and
`provided to the headlight directional controller 14.
`In a second step 32 of the table generating algorithm 30,
`the table is generated using the adjustment control algorithm
`selected in the ?rst step 31. The table can be generated in any
`desired manner. For example, let it be assumed that the
`selected adjustment control algorithm relates a single sensed
`operating condition to each of the angular adjustment con
`trol values for adjusting both the up/doWn orientation and
`the left/right orientation of the headlight 11. The table can be
`generated by initially selecting a ?rst discrete sensed op