111111
`
`1111111111111111111111111111111111111111111111111111111111111
`US007241034B2
`
`c12) United States Patent
`Smith et al.
`
`(10) Patent No.:
`(45) Date of Patent:
`
`US 7,241,034 B2
`Jul. 10, 2007
`
`(54) AUTOMATIC DIRECTIONAL CONTROL
`SYSTEM FOR VEHICLE HEADLIGHTS
`
`(75)
`
`Inventors: James E. Smith, Berkey, OH (US);
`Anthony B. McDonald, Perrysburg,
`OH (US)
`
`(73) Assignee: Dana Corporation, Toledo, OH (US)
`
`( *) Notice:
`
`Subject to any disclaimer, the term of this
`patent is extended or adjusted under 35
`U.S.C. 154(b) by 0 days.
`
`4,066,886 A
`4,162,424 A
`4,186,428 A
`4,204,270 A
`4,217,631 A
`4,225,902 A
`4,310,172 A
`4,549,277 A
`4,583,152 A
`4,768,135 A
`
`111978 Martin ....................... 362/465
`711979 Zillgitt et al ................ 362/467
`111980 Deverrewaere ............. 362/466
`5/1980 d'Orsay ...................... 362/466
`8/1980 Bergkvist ................... 362/466
`9/1980 Ishikawa et a!. ............ 318/696
`111982 Claude et a!.
`.............. 362/466
`10/1985 Brunson eta!.
`4/1986 Kawai eta!. ............ 280/6.158
`8/1988 Kretschmer et a!. .......... 362/40
`
`(Continued)
`
`FOREIGN PATENT DOCUMENTS
`
`(21) Appl. No.: 10/285,312
`
`(22) Filed:
`
`Oct. 31, 2002
`
`EP
`
`0306611
`
`3/1989
`
`(Continued)
`
`(65)
`
`Prior Publication Data
`
`US 2003/0107898 Al
`
`Jun. 12, 2003
`
`Primary Examiner-Ali Alavi
`(74) Attorney, Agent, or Firm-MacMillan, Sobanski &
`Todd, LLC
`
`Related U.S. Application Data
`
`(57)
`
`ABSTRACT
`
`(60) Provisional application No. 60/369,447, filed on Apr.
`2, 2002, provisional application No. 60/356,703, filed
`on Feb. 13, 2002, provisional application No. 60/335,
`409, filed on Oct. 31, 2001.
`
`(51)
`
`Int. Cl.
`B60Q 1100
`(2006.01)
`B60R 22100
`(2006.01)
`(52) U.S. Cl. ......................................... 362/465; 701/49
`(58) Field of Classification Search .................. 362/37,
`362/465-466; 315/82; 701/49
`See application file for complete search history.
`
`(56)
`
`References Cited
`
`U.S. PATENT DOCUMENTS
`
`3,634,677 A
`3,939,339 A
`3,953,726 A
`4,024,388 A
`
`............ 362/467
`111972 Stuttgart et a!.
`2/1976 Alphen ....................... 362/467
`4/1976 Scarritt, Sr .................. 362/465
`511977 Skoff ......................... 362/467
`
`10~
`
`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 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 headlight 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.
`
`5 Claims, 7 Drawing Sheets
`
`.. =G
`
`INPUT/OUTPUT
`DEVICE
`
`CONDITION
`SENSOR
`
`CONDITION
`
`15
`
`Page 1 of 476
`
`

`
`US 7,241,034 B2
`Page 2
`
`U.S. PATENT DOCUMENTS
`
`4,791,343 A
`4,833,573 A
`4,868,720 A
`4,868,721 A
`4,870,545 A
`4,891,559 A
`4,907,877 A
`4,908,560 A
`4,916,587 A
`4,943,893 A
`4,948,249 A
`5,060,120 A
`5,099,400 A
`5,158,352 A
`5,164,785 A
`5,181,429 A
`5,193,894 A
`5,331,393 A
`5,373,357 A
`5,392,111 A
`5,404,278 A
`5,426,571 A
`5,428,512 A
`5,485,265 A
`5,526,242 A
`5,550,717 A
`5,633,710 A
`5,660,454 A
`5,707,129 A
`5,751,832 A
`5,779,342 A
`
`12/1988 Ahrendt ...................... 362/348
`5/1989 Miyauchi et a!. ........... 362/466
`9/1989 Miyauchi et a!. ........... 362/466
`9/1989 Soardo ....................... 362/466
`9/1989 Hatanaka et a!.
`............. 315/82
`111990 Matsumoto et a!.
`........ 356/121
`3/1990 Fukuda eta!. .............. 318/603
`3/1990 Shibata et a!. .............. 318/603
`4/1990 Hirose eta!. ............... 362/460
`7/1990 Shibata et a!. ................ 362/37
`8/1990 Hopkins et a!.
`............ 356/121
`10/1991 Kobayashi et al.
`......... 362/465
`3/1992 Lee ............................. 362/37
`10/1992 Ikegarni et a!. ............. 362/359
`1111992 Hopkins et a!.
`............ 356/121
`111993 Sieber ....................... 74/89.42
`3/1993 Lietar et al. ................ 362/466
`............ 356/121
`7/1994 Hopkins et a!.
`12/1994 Hopkins et a!.
`............ 356/121
`2/1995 Murata eta!. .............. 356/121
`4/1995 Shibata et a!. .............. 362/464
`6/1995 Jones ......................... 362/466
`6/1995 Mouzas ...................... 362/466
`111996 Hopkins ..................... 356/121
`6/1996 Takahashi et al. .......... 362/466
`8/1996 Liao ........................... 362/467
`5/1997 Kurnra ....................... 362/464
`8/1997 Mori eta!.
`111998 Kobayashi .................. 362/464
`5/1998 Panter eta!. ............... 362/104
`7/1998 Kluge
`........................ 362/507
`
`................. 340/468
`7/1998 Bitar et al.
`5,781,105 A
`7/1998 Huhn ......................... 362/459
`5,785,405 A
`2/1999 Speak et a!. .................. 362/37
`5,868,488 A
`5,877,680 A
`3/1999 Okuchi eta!. .............. 340/468
`4/1999 Zillgitt ....................... 340/468
`5,896,011 A
`............ 307/10.8
`5/1999 Hayarni et a!.
`5,907,196 A
`6/1999 Gotoh ......................... 362/37
`5,909,949 A *
`7/1999 Panter eta!. ............... 356/121
`5,920,386 A
`8/1999 Hege .......................... 362/459
`5,938,319 A
`1111999 Miller eta!. ................ 310/103
`5,977,678 A
`1/2000 Gotou ........................ 362/460
`6,010,237 A
`4/2000 Kobayashi ................... 701/49
`6,049,749 A *
`8/2000 Diep ........................... 315/82
`6,097,156 A
`9/2000 Hibbard et a!. . ............ 250/205
`6,118,113 A
`1112000 Zillgitt et al ................ 362/466
`6,142,655 A
`1112000 Lopez eta!. .................. 315/82
`6,144,159 A
`1/2001 Prevost et a!. ................ 362/37
`6,176,590 B1
`2/2001 Toda eta!. ................. 362/465
`6,183,118 B1
`6,193,398 B1 *
`2/2001 Okuchi eta!. . ............. 362/466
`5/2001 Hogrefe et a!. ............. 362/539
`6,227,691 B1
`6,231,216 B1
`5/2001 Frasch ........................ 362/464
`5/2001 Okuchi eta!. .............. 362/466
`6,234,654 B1
`6,281,632 B1
`8/2001 Starn eta!. ................... 315/82
`9/2001 Hayarni et a!.
`............. 362/465
`6,293,686 B1
`6,305,823 B1* 10/2001 Toda eta!. ................. 362/276
`200110019225 A1
`9/2001 Toda eta!.
`
`FOREIGN PATENT DOCUMENTS
`
`EP
`1142757
`EP
`1275555
`GB
`2340925
`* cited by examiner
`
`10/2001
`112003
`3/2000
`
`Page 2 of 476
`
`

`
`U.S. Patent
`
`Jul. 10, 2007
`
`Sheet 1 of 7
`
`US 7,241,034 B2
`
`11
`
`12
`
`\
`
`UP/DOWN
`ACTUATOR
`
`POSITION
`FEEDBACK
`SENSOR
`
`18
`
`~ 19
`
`POSITION
`FEEDBACK
`SENSOR
`
`LEFT/RIGHT
`ACTUATOR
`
`~ '
`
`13
`
`..
`
`r 14
`
`HEADLIGHT
`DIRECTIONAL
`CONTROLLER
`
`t
`
`•
`
`FIG. 1
`
`1 7
`
`\
`
`INPUT/OUTPUT
`DEVICE
`
`CONDITION
`SENSOR
`
`CONDITION
`SENSOR
`
`_/
`
`15
`
`_/
`
`16
`
`Page 3 of 476
`
`

`
`U.S. Patent
`
`Jul. 10, 2007
`
`Sheet 2 of 7
`
`US 7,241,034 B2
`
`ENTER CALIBRATION v- 21
`
`MODE
`
`,,.
`ACTUATORS TO AIM v- 22
`MANUALLY OPERATE
`
`HEADLIGHT IN
`REFERENCE ORIENTATION
`
`,,
`
`20
`
`~
`
`FIG. 2
`
`STORE POSITION IN
`HEADLIGHT DIRECTIONAL ~ 23
`CONTROLLER AS
`REFERENCE POSITION
`
`Page 4 of 476
`
`

`
`U.S. Patent
`
`Jul. 10, 2007
`
`Sheet 3 of 7
`
`US 7,241,034 B2
`
`SELECT ADJUSTMENT
`CONTROL ALGORITHM
`
`r
`
`31
`
`30
`
`~
`
`GENERATE TABLE OF
`CONDITION VS.
`ADJUSTlvffiNT CONTROL
`VALUES
`
`1 ~ 32
`V
`
`FIG. 3
`
`STORE TABLE IN
`33
`HEADLIGHT DIRECTIONAL ~
`CONTROLLER
`
`Page 5 of 476
`
`

`
`U.S. Patent
`
`Jul. 10, 2007
`
`Sheet 4 of 7
`
`US 7,241,034 B2
`
`40
`
`/
`
`LEFT/RIGHT
`ADJUSTMENT
`FACTORS
`+4.50°
`+3.75°
`+3.00°
`+2.25°
`+ 1.50°
`+0.75°
`0.00°
`-0.75°
`-1.50°
`-2.25°
`-3.00°
`-3.75°
`-4.50°
`
`SENSED CONDITION
`(STEERING ANGLE)
`VALUES
`+60
`+50
`+40
`+30
`+20
`+1 0
`oo
`-10
`-20
`-30
`-40
`-50
`-60
`
`UP/DOWN
`ADJUSTMENT
`FACTORS
`-3.00°
`-2.50°
`-2.00°
`-1.50°
`-1.00°
`-0.50°
`0.00°
`-0.50°
`-1.00°
`-1.50°
`-2.00°
`-2.50°
`-3.00°
`
`FIG. 4
`
`Page 6 of 476
`
`

`
`U.S. Patent
`
`Jul. 10, 2007
`
`Sheet 5 of 7
`
`US 7,241,034 B2
`
`READ VALUE OF
`CONDITIO>l SENSOR
`
`~50
`
`51
`
`52
`
`57
`
`58
`
`YES
`
`54
`
`55
`
`IS CONDITION
`SENSOR VALUE
`IN TABLE?
`
`NO
`
`LOOKUP ADJUSTMENT
`FACTORSINTABLEFOR
`ADJACENT CONDITION
`SENSOR VALUES
`
`INTERPOLATE
`ADWSTMENT FACTOR
`
`53
`
`LOOKUP ADJUSTMENT
`FACTORS IN TABLE FOR
`SENSED CONDITION
`SENSOR VALUE
`
`COMPARE ADJUSTMENT
`FACTORSvnTHCURRENT
`HEADLIGHT POSITION
`
`NO
`
`M~GNITUDE OI'
`ADJUSTMENT
`GREATER THAN
`THRESHOLD?
`
`56
`
`YES
`
`ENERGIZE HEADLIGHT
`ACTUATORS
`
`FIG. 5
`
`Page 7 of 476
`
`

`
`U.S. Patent
`
`Jul. 10, 2007
`
`Sheet 6 of 7
`
`US 7,241,034 B2
`
`READ FIRST VALUE OF v 61
`CONDITION SENSOR ~
`
`60
`
`u•
`
`READ SECOND VALUE OF v 62
`
`CONDITION SENSOR
`
`FIG. 6
`
`,lr
`
`CALCULATE RATE OF
`CHANGE OF SENSED ~ 63
`CONDITION
`
`,,
`ENERGIZE HEADLIGHT ~ 64
`ACTUATORS
`
`Page 8 of 476
`
`

`
`U.S. Patent
`
`Jul. 10, 2007
`
`Sheet 7 of 7
`
`US 7,241,034 B2
`
`~70
`71 ~
`
`READ FIRST VALUE OF
`CONDITION SENSOR
`
`READ SECOND VALUE OF
`CONDITION SENSOR
`
`72
`
`CALCULATE RATE OF
`CHANGE OF SENSED
`CONDITION
`
`~ 73
`
`74
`
`NO
`
`IS RATE OF
`CHANGELESS
`THAN
`THRESHOLD?
`
`FIG. 7
`
`YES
`~------~--------~~ 75
`
`ENERGIZE HEADLIGHT
`ACTUATORS
`
`Page 9 of 476
`
`

`
`US 7,241,034 B2
`
`2
`SUMMARY OF THE INVENTION
`
`1
`AUTOMATIC DIRECTIONAL CONTROL
`SYSTEM FOR VEHICLE HEADLIGHTS
`
`CROSS REFERENCE TO RELATED
`APPLICATIONS
`
`This application claims the benefit of U.S. Provisional
`Application Nos. 60/335,409, filed Oct. 31, 2001; 60/356,
`703, filed Feb. 13, 2002; and 60/369,447, filed Apr. 2, 2002,
`the disclosures of which are incorporated herein by refer(cid:173)
`ence.
`
`BACKGROUND OF THE INVENTION
`
`This invention relates to an improved structure and
`method for operating a directional control system for vehicle
`5 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
`10 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
`15 signal. An actuator is adapted to be connected to the head(cid:173)
`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
`20 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(cid:173)
`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 flow chart of an algorithm for calibrating the
`automatic directional control system illustrated in FIG. 1 so
`as to define an initial reference position for the headlight
`from which the headlight directional controller can imple(cid:173)
`ment directional angle adjustments.
`FIG. 3 is a flow 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 flow chart of an algorithm for operating the
`headlight directional controller illustrated in FIG. 1 to auto(cid:173)
`matically implement directional angle adjustments in accor(cid:173)
`dance with sensed condition values.
`FIG. 6 is a flow chart of an algorithm for operating the
`headlight directional controller illustrated in FIG. 1 to auto(cid:173)
`matically implement directional angle adjustments in accor(cid:173)
`dance with the rate of change of one or more of the sensed
`condition values.
`FIG. 7 is a flow chart of an algorithm for operating the
`headlight directional controller illustrated in FIG. 1 to auto-
`55 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(cid:173)
`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(cid:173)
`ally at 10, for a vehicle headlight 11 in accordance with this
`invention. The illustrated headlight 11 is, of itself, conven(cid:173)
`tional in the art and is intended to be representative of any
`
`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 25
`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 30
`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. 35
`In the past, these headlights have been mounted on the
`vehicle in fixed positions relative thereto such that the beams
`oflight are projected therefrom at predetermined directional
`aiming angles relative to the vehicle. Although such fixed
`aiming angle headlight systems have and continue to func- 40
`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 45
`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 50
`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(cid:173)
`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 60
`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(cid:173)
`trol systems have been found to be deficient for various
`reasons. Thus, it would be desirable to provide an improved 65
`structure for an automatic headlight directional control sys(cid:173)
`tem that addresses such deficiencies.
`
`Page 10 of 476
`
`

`
`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 marmer that a beam of light is 5
`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 10
`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 monnted on
`the vehicle such that the angle at which the beam of light
`projects therefrom can be adjusted both (I) 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(cid:173)
`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 effect 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 fonnd to be
`desirable to use microstepping motors for the actuators 12
`and 13. Such micro stepping 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(cid:173)
`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 com1ected 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(cid:173)
`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
`
`4
`desired to generate electrical signals that are representative
`of any other operating conditions of the vehicle. A conven(cid:173)
`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 first 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(cid:173)
`tive electrical signals that are representative of the actual
`up/down and left/right positions of the headlight 11. Thus,
`15 the first 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
`20 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
`25 feedback sensors 18 and 19 can be embodied as any con(cid:173)
`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
`30 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
`35 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 flag or other
`component that is mounted on or connected to the headlight
`11 for movement therewith. Each of the optical interrupters
`40 further includes an optical source and sensor assembly. As
`the headlight 11 is moved by the actuators 12 and 13, the flag
`moves therewith relative to the optical source and sensor
`assembly between a first position, wherein the flag permits
`light emitted from the source from reaching the sensor, and
`45 a second position, wherein the flag prevents light emitted
`from the source from reaching the sensor. When the flag is
`in the first position relative to the optical source and sensor
`assembly, the sensor is permitted to receive light emitted
`from the source. As a result, a first signal is generated from
`50 the optical source and sensor assembly to the headlight
`directional controller 14. Conversely, when the flag 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
`55 from the optical source and sensor assembly to the headlight
`directional controller 14. Thus, the edge of the flag defines
`a transition between the first and second positions of the flag
`relative to the optical source and sensor assembly and,
`therefore, defines a predetermined up/down or left/right
`60 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 first 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,
`65 for example) that the headlight 11 is positioned. The purpose
`for such position feedback sensors 18 and 19 will be
`discussed below.
`
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`US 7,241,034 B2
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`5
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`5
`FIG. 2 is a flow chart of an algorithm, indicated generally
`at 20, for calibrating the automatic directional control sys(cid:173)
`tem illustrated in FIG. 1 so as to define an initial reference
`position or positions for the headlight 11 from which the
`headlight directional controller 14 can implement direc-
`tiona! angle adjustments. As mentioned above, the headlight
`11 is mounted on the vehicle such that the angle at which the
`beam oflight 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 10
`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(cid:173)
`sequent directional angle adjustments can be made by the
`headlight directional controller 14 from the pre-established 15
`reference position or positions established by this calibration
`algorithm 20.
`To accomplish this, the calibration algorithm 20 has a first
`step 21 wherein the headlight directional controller 14 is
`caused to enter a calibration mode of operation. In the 20
`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- 25
`tiona! controller 14 is in the calibration mode of operation,
`an operator of the input/output device 17 can manually effect
`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 30
`up/down actuator 12 and the left/right actuator 13 are
`manually operated to aim the headlight 11 in a predeter(cid:173)
`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 35
`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 40
`structure of the headlight 11 such that the center of the beam
`therefrom is projected at the reference target. In this inven(cid:173)
`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 45
`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 50
`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 55
`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 60
`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(cid:173)
`back sensors 18 and 19 are adapted to generate respective
`electrical signals that are representative of the actual 65
`up/down and left/right positions of the headlight 11 or of the
`predetermined positions for the headlight. Thus, the first
`
`6
`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(cid:173)
`trical signal to the headlight directional controller 14 that is
`representative thereof. Similarly, the second position feed(cid:173)
`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(cid:173)
`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(cid:173)
`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 flow 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(cid:173)
`mented by the headlight directional controller 14, and fur(cid:173)
`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 first 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(cid:173)
`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-
`
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`tative of the