2
`
`.o STATES PATENT AND TRADE. V RK OFFICE
`Iii THE UI~.
`REQUEST FOR FILING NATIONAL PATENT APPLICATION
`
`Under 35 USC 111(al and Rule 53(bl
`
`’
`
`.4‘
`
`0I
`
`.
`
`Illlllll
`
`pmmissioner of Patents
`_ 'ngton, D.C. 20231
`
`‘_
`
`WITH SIGNED DECLARATION
`
`NONPROVISI
`NON REISSUE
`NON PCT NAT PHASE
`
`F &
`
`
`
`66/9I/9IlaiiiiiiiiiiiIii
`
`Herewilh is the PATENT APPLICATION of
`|nventor(s): OKUCHI, et al.
`
`(Our Deposit Account No. 03-3975).
`Our Order No.
`30954
`
`260373
`
`Title
`
`SYSTEM FOR AUTOMATICALLY ADJUSTING OPTICAL
`AXIS DIRECTION OF VEHICLE HEADLIGHT
`
`A
`
`Atty. Dkt.:
`
`PM 260373
`Mtt
`
`52924-US-KK
`
`including:
`
`-
`
`Date: June 16, I999
`
`W
`
`.4
`
`2. [Z] Specification in non,-English language
`pages (only spec. and claims)
`62
`Specification:
`Abstract
`1
`page(s);
`9
`numbered claims
`IX Original
`[:1 Facsimile/Copy
`Declaration
`Z] A4
`formal of size:
`[:1 11"
`18
`sheet(s)
`E] informal;
`.,E Drawings: «
`I] See top first page re prior Provisional, National or International application(s). ("X" box only if info is there and do not
`complete corresponding item 5 or 6). (Prior M#
`SN
`AMEND the specification please by inserting before the first line: -- This is a
`E] Continuation-in-Part
`El Divisional
`E] Continuation
`E] Substitute Application (MPEP 201.69) of:
`ji.6(a) E] National Appln. No.
`filed
`.(M#
`l
`‘E
`=F'
`can [3 International Appln. No.
`filed
`
`I
`
`.
`
`"“'
`
`-- This application claims the benefit of U.S.
`. [] AMEND the specification by inserting before the first line:
`Provisional Application No. 60/
`,liled
`. --
`Attached is an assignment and cover sheet. Please return the recorded assignment to the undersigned.
`.
`9. D Prior application is assigned to
`
`by Assignment recorded
`
`Reel
`
`Frame
`
`10. FOREIGN priority is claimed under 35 USC 119(a)-(d)/365(b) based on filing in
`1 1 .
`
`JAPAN
`
`(country)
`
`Apiication No.
`(1) 10467626
`
`Filing Date
`June16, 1998
`
`A lication No.
`(2)
`10-244782
`
`Filln Date
`August 31, 1998
`
`April 15, 1999
`11-107852
`4
`Aril15,199
`3 11-107851
`AriI15.1999 _—
`(5 11407853
`_I5——
`——
`5
`(No.) Certified copy (copies):
`attached;
`[:1 previously filed (date)
`in U.S. Application No.
`filed on
`
`/
`
`1
`
`SL-1018
`
`

`
`(No.) Verified Statement(s) establishing "small entity” status under Rules 9 & 27.
`13. E] Attached:
`14. DOMESTIC/INTERNATIONAL“priority is claimed under 35 USC 119(9)/120/365(0) based on the following provisional,
`nonprovisional and/or PCT international a - lication s :
`
`'
`A - lication No.
`Filin Date
`A lication No.
`—lEI—
`
`IEI—Il5_
`
`15. E] This application is being filed under Rule 53(b)(2) since an inventor is named in the enclosed Declaration who was not
`named in the prior application.
`‘
`16.
`Attached: Form PTO-1449 and copy of listed documents.
`
`17. E] Preliminary Amendment:
`
`THE FOLLOWING FILING FEE IS BASED ON CLAIMS AS FILED LESS ANY ABOVE CANCELLED
`
`$760/$380
`.
`8. Base Filin
`$19. Total Eliective Claims DE— x$t8/$9 =
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`|ndeendentClaimS
`X $78/$39=
`E.
`51:
`‘if answer is zero or less, enter "0”
`
`$760
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`Largelsmall Entity
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`if_a_r_iy p_r_o_ge;multiple dependent claim (ignore improper) is present, add
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`9 ; Leave this line bla it this is a reissue a lication
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`;_;21.
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`25. [:1 Attached is a Petition/Fee under Rule No.
`26
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`
`$916
`+ 0
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`TOTAL FEE ENCLOSED = I $956
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`Fee
`Code
`101/201
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`M202
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`104/204
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`139
`531
`122
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`CHARQE S LATEMENT: The Commissioner is hereby authorized to charge any fee specifically authorized hereafter, or any missing or insuffieient fee(s) filed, or
`asserted to be filed. or which should have been filed herewith or concerning any paper filed hereafter. and which may be required under Rules 16-18 (missing gr
`igsufticient fee only) now or hereafter relative to this application and the resulting Official document under Rule 20, or credit any overpayment, to our
`Account/Order Nos. shown in the heading hereof for which purpose a duplicate copy of this sheet is attached.
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`ThisICHARGE STATEMENT does not authorize charge of the issue fee until/unless an issue fee transmittal form is filed.
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`Pillsbury Madison & Sutro LLP
`Intellectual Property Group
`
`I100 New York Avenue, N.W.
`Ninth Floor, East Tower
`Washington, DC. 20005-3918
`Tel: (202)861-3000
`GLK/rgf
`
`By Atty:
`
`G. Lloyd Knight
`
`Reg. No.
`
`17698
`
`Sig:
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`'
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`/
`
`I
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`NOTE: File in duplicate with 2 post card receipts (PAT-103) & attachments
`
`Fax: (202) 322-0944 __
`Tel: (202) 861 -3090
`
`PAT-I02 (UTILITY APPLN.) 5/99
`
`2
`
`

`
`IN THE UNITED STATES PATENT AND TRADEMARK OFFICE
`REQUEST FOR FILING NATIONAL PATENT APPLICATION
`Under 35 USC 111(a) and Rule 53(b)
`/
`’
`
`~
`
`'
`PATENT APPLICATION
`
`Asst. Commissioner of Patents
`
`WITH SIGNED DECLARATION
`
`Washington, D.C. 20231
`
`"
`
`NONPROVISIONAL
`NON REISSUE
`NON PCT NAT PHASE
`
`Sir:
`
`' I-lerewith is the PATENT APPLICATION of
`lnventor(s): OKUCHI, et at.
`
`I
`
`(Our Deposit Account No. 08-3975)
`Our Order No.
`
`Title
`
`SYSTEM FOR AUTOMATICALLY ADJUSTING OPTICAL
`AXIS DIRECTION OF VEHICLE HEADLIGHT
`,
`‘
`
`Atty. Dkt.:
`
`‘
`PM 260373
`
`52924-US~KK
`
`including:
`
`-
`
`Date: June 16, 1999
`
`62
`
`2. 1] Specification in non-English language
`pages (only spec. and claims)
`1. Specification:
`Abstract
`1 , page(s);
`'
`9
`numbered claims
`Original
`I:l Facsimile/Copy
`3. Declaration
`A4
`formal of size:
`I] 11”
`18
`sheet(s)
`[:1 informal;
`4.
`Drawings:
`5. El See top first page re p_rior Provisional, National or International application(s). ("X" box only it into is there and do not
`complete corresponding item 5 ore). (Prior M#
`SN
`6. AMEND the specification please by inserting before the first line: -- This is a
`E] Continuation-In;Pért
`[:1 Divisional
`[:1 Continuation
`[:| Substitute Application (MPEP 201.09) of:
`.M#
`6(a) [I National Appln. No.
`’
`tiled
`(
`)
`6(b) E] International Appln. No.
`filed
`
`I
`
`,
`
`an
`
`-- This application claims the benefit of U.S.
`7. I] AMEND the specification by inserting before the first line:
`Provisional Application No. 60/
`v
`, tiled
`.
`Attached is an assignment and coversheet. Please return the recorded assignment to the undersigned.
`8.
`9. [I Prior application is assigned to
`
`by Assignment recorded
`
`Reel
`
`Frame
`
`10. FOREIGN priority is claimed under 35 USC Il9(a)-(d)/365(b) based on filing in
`11.
`
`JAPAN
`
`(country)
`
`Apiication No.
`(1) 10467626
`(3
`11)-107851
`5 11407853 l'6——
`I —lB——
`——
`(Nc.) Certified copy (copies): E attached;
`I] previously filed (date)
`in U.S. Application No.
`I
`filed on
`
`5
`
`3
`
`

`
`(No.) Verified Statement(s) establishing “small entity" status under Rules 9 & 27.
`I
`13. D Attached:
`14. DOMESTIC/INTERNATIONAL priority is claimed under 35 USC 119(9)/120/365(0) based on the following provisional,
`nonprovisional and/or PCT international a llcation s 1
`Alicationwo.
`Alication No.
`—l_—
`
`15. E] This application is being filed under Rule 53(b)(2) since an inventor is named in the enclosed Declaration who was not
`named in the prior application.
`16.
`Attached: Form PTO—1449 and copy of listed documents.
`
`17. I] Preliminary Amendment:
`
`I
`
`THE FOLLOWING FILING FEE IS BASED ON CLAIMS AS FILED LESS ANY ABO\./E CANCELLED
`
`18. Basic Filin Fee
`
`21. If §l_n_y proper multiple dependent claim (ignore improper) is present , add
`Leave this line lank if this is a reissue a llcation
`22.
`23. lf.“non-Enlish” box 2 is X’d, add Rule 17 k rocessin iee
`24. it "assinment” box 6 is X’d, add recordin fee
`
`TOTAL FILING FEE ENCLOSED .=
`
`Largelsmall Entity
`
`$760/$380‘
`x $18/$9 =
`x $78/$39 =
`
`+ $260/$130
`
`Code
`101/201
`103/203
`102/202
`
`104/204
`
`139
`
`.$7eo
`
`+ 156
`
`+ 0
`
`,
`
`0
`
`+
`$956
`
`26.
`
`TOTAL FEE ENCLOSED =
`
`CflARGE STATEMENT: The Commissioner is hereby authorized to charge any fee specifically authorized hereafter, or any missing orbinsufficient fee(s) filed, or
`asserted to be filed, or which should have been filed herewith or concerning any paper filed hereafter, and which may be required under Rules 16-18 (missing or
`insufficient fee only) now or hereafter relative to this application and the resulting Official document under Rule 20, or credit any overpayment, to our
`Account/Order Nos. shown in the heading hereof for which purpose a duplicate copy of this sheet is attached.
`This CHARGE STATEMENT does not authorize charge of the issue fee until/unless an issue fee transmittal form is filed.
`
`Pillsbury Madison & Sutro LLP
`Intellectual Property Group
`
`1100 New York Avenue, N.W.
`Ninth Floor, East Tower
`Washington, D.C. 20005-3918
`Tel: (202) 861-3000
`GLK/rgf
`
`By Atty:
`
`G. Lloyd l{night
`
`-
`
`Reg. No.
`
`17698
`
`,
`Sig:
`'
`NOTE: File in duplicate with 2 post card receipts (PAT-103) & attachments
`
`.
`
`Fax: (202) 822-0944
`Tel: (202) 861-3090
`
`t
`
`4
`
`

`
`APPLICATION UNDER UNITED STATES PATENT LAWS
`
`Invention:
`
`SYSTEM FOR AUTOMATICALLY ADJUSTING OPTICAL AXIS
`DIRECTION OF VEHICLE HEADLIGHT
`
`Inventor(s):
`
`Hiroaki OKUCHI
`Kenichi NISHIMURA
`
`Pillsbury Madison & Sutro LLP
`Intellectual Property Group
`1100 New York Avenue, N.W.
`Ninth Floor, East Tower
`Washington, D.C. 20005-3918
`Attorneys
`Telephone:
`-
`(202) 861-3000
`
`This is a:
`
`Cl
`
`Provisional Application
`
`E Regular Utility Application
`
`DDDDDEI
`
`Continuing Application
`
`PCT National Phase Application
`
`Design Application
`
`Reissue Application
`
`‘Plant ‘Application
`
`Substitute Specification
`Sub. Spec. filed
`in App. No
`
`El Marked Up Specification re
`Sub. Spec. filed
`in App. No.
`
`SPECIFICATION
`
`PA'l‘.1fi(l 6/Q0
`
`5
`
`

`
`SYSTEM FOR AUTOMATICALLY ADJUSTING
`
`OPTICAL AXIS DIRECTION OF VEHICLE HEADLIGHT
`
`CROSS REFERENCE TO RELATED APPLICATION
`
`This application relates to and incorporates herein by
`reference Japanese Patent Applications No. 10—167626, No.
`10—244782, No.
`ll—107851, No. 11—107852 and l1—107953 filed
`
`on June 16, 1998, August 31, 1998, April 15, 1999, April 15,
`
`1999 and April 19, 1999, respectively.
`
`BACKGROUND OF THE INVENTION
`
`1.
`
`Field of the invention
`
`The present
`
`invention relates to a vehicle headlight
`
`optical axis direction adjusting system for automatically
`
`adjusting the optical axis direction of irradiation of a
`
`headlight provided for a vehicle.
`
`2. Description of Related Art
`
`conventionally, in the headlight of a vehicle, when the
`
`optical axis of the a headlight is directed upward due to
`
`inclination of the chassis of the vehicle, glare is given
`
`to an on-coming vehicle or the like. When the optical axis
`
`is directed downward, a driver of the vehicle may lose the
`
`far field of view. There has been, consequently, a demand
`
`for holding the optical axis direction of the headlight
`
`unchanges as much as possible.
`
`JP—A~9—301055 discloses a vehicle headlight optical
`
`axis control system,
`
`in which a control mode
`
`is set
`
`in
`
`'/3
`
`6
`
`

`
`accordance with acceleration,
`
`a
`
`filtering process
`
`is.
`
`executed when
`
`the
`
`acceleration
`
`is
`
`smaller
`
`than
`
`a
`
`predetermined value, the filtering process is not performed
`
`so as not to delay switching of the control mode when the
`
`acceleration is equal to or larger than the predetermined
`value, and the optical axis direction of the headlight is
`
`adjusted on the basis of a change in the height of the vehicle
`
`on each occasion.
`
`In the above system, when the acceleration of the level
`
`which can not be reached in a normal driving state is sensed
`
`in association with a known traction (TRC) control or
`
`antilock brake (ABS) control, since the acceleration is
`
`equal
`
`to or
`
`larger
`
`than ‘the predetermined value,
`
`the
`
`filtering process is not performed and the control mode is
`
`frequently switched. At the timecnfacceleration associated
`
`with the TRC control
`
`(TRC control time) or at the time of
`
`deceleration associated with the ABS control
`
`(ABS control
`
`time),
`
`although the acceleration largely changes,
`
`the
`
`vehicle posture does not change so much. As a result, the
`
`optical axis is improperly controlled when the direction of
`
`the optical axis of
`
`the headlight
`
`is allowed to follow
`
`changes in the acceleration at such time.
`
`Anotheropticalaxiscontrolsystem hsknownwhichuses
`
`an inclination angle obtained by approximating an amount of
`
`change in the vehicle posture caused by loading to a linear
`expression. According to this control,
`the optical axis
`
`direction of the headlight can be made to coincide with the
`
`7
`
`

`
`vehicle posture under a limited loading condition such as
`
`"only occupant
`
`load" or "occupant
`
`load and up to 50 kg of
`
`trunk load".
`
`However, various
`
`loading conditions of
`
`combination of the occupant load and the trunk load can not
`
`be dealt with.
`
`In a still another system, a vehicle height sensor is
`
`installed only on either the right or left side of a rear
`
`wheel since front wheels are wheels to be steered and an
`
`installation space is limited.
`
`A front height value is
`
`estimated on the basis of a rear height value in the stop
`
`mode of the vehicle to calculate the inclination angle. When
`
`the vehicle is stopped riding on a block or the like, a rear
`
`height value different from that on a flat road is sensed.
`
`In one trip (a driving interval between stops of the vehicle)
`
`after that,there isconseguentlyan inconveniencesuch that
`
`a computation error occurs in the inclination angle in the
`
`longitudinal direction of the vehicle and the optical axis
`direction of
`the headlight
`is deviated.
`Since the rear
`
`height value changes due to turning which is a rotary motion
`
`around the longitudinal axis of the vehicle during a turn
`
`although the vehicle is not
`
`inclined in the longitudinal
`
`direction,
`
`a computation error occurs in the inclination
`
`angle in the longitudinal direction of the vehicle until the
`
`turn of the vehicle is finished and there is an inconvenience
`
`such that the optical axis direction of the headlight is
`
`accordingly deviated.
`
`8
`
`

`
`SUMMARY OF THE INVENTION
`
`The present invention has an object to properly adjust
`
`the optical axis direction of a headlight in accordance with
`
`a driving state of a vehicle without frequently switching
`
`the optical axis direction of the headlight.
`The present invention has another object to deal with
`
`various loading conditions in the event of automatically
`
`adjusting the optical axis direction of a headlight of a
`
`vehicle on the basis of an output of a single vehicle height
`
`sensor.
`
`The present invention has a further object to properly
`
`correct a deviation in optical axis direction of a headlight
`
`when the vehicle is either stopped riding on a block or the
`
`like or is in a turn state.
`
`According to one aspect of the present invention, an
`
`inclination angle in the optical axis direction of
`
`a
`
`headlight of a vehicle to the horizontal plane is calculated
`
`on the basis of output values fron1two vehicle height sensors
`
`arranged on the front
`
`and rear sides of
`
`the vehicle,
`
`respectively.
`
`A filter for changing the response oft
`
`adjustment of the optical axis direction of the headlight
`
`is
`
`switched depending on a control mode determined in
`
`correspondence with a vehicle speed and acceleration. when
`
`Vthe acceleration exceeds the highest determination level
`
`which is set so as not to be reached in a normal driving state,
`
`the control mode corresponding to the acceleration state or
`
`the deceleration state_of the vehicle is continued unless
`
`9
`
`

`
`a constant
`
`speed state of
`
`the vehicle continues
`
`for
`
`a
`
`predetermined period after that.
`
`According to another aspect of the present invention,
`inclinationanglei11anopticalaxisdirectionof’aheadlight
`
`to the horizontal plane is calculated on the basis of an
`
`output value from a single vehicle height sensor by using
`
`a prediction expression which is divided into a plurality
`
`ofregions«ofvehiclepostureshavingdifferentinclinations
`
`in accordance with loading conditions of an occupant
`load
`anda trunkload. Theoptical.axisdirectionof theheadlight
`
`is adjusted on the basis of the inclination angle.
`
`For
`
`example,bypreparingthepredictionexpressiondividedinto
`
`apluralityofregionsofvehicleposturesinaccordancewith
`
`the loading conditions of the occupant load and the trunk
`
`load in correspondence with the vehicle type and the like.
`
`Preferably,
`
`the inclination angle is calculated from both
`
`of the output of the single vehicle height sensor and an error
`
`which occurs in association with installation of the vehicle
`
`heightlsensor.
`
`According to a further aspect of the invention, when
`
`it is determined that a driving mode of a vehicle is a stable
`
`driving mode, a reference inclination angle in the vehicle‘
`
`stop mode is updated based on an output of a vehicle height
`
`sensor,
`
`the inclination angle in the driving mode
`
`is
`
`corrected on the basis of
`
`the reference angle, and the
`
`optical axis directioncxfthe headlight is thereby adjusted.
`
`When the vehicle once enters the constant speed driving mode
`
`10
`
`

`
`before completion of one trip, irrespective of the presence
`
`or absence of a deviation in the optical axis direction of
`
`the headlight of
`
`the vehicle,
`
`the reference inclination
`
`angle in the vehicle stop mode is updated and the inclination
`
`anglejxxthe drivingnmde iscorrected. Thus,an effect such
`
`that even if the optical axis direction of the headlight is
`
`deviated, it can be properly adjusted is obtained.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`In the accompanying drawings:
`
`Fig.
`
`1
`
`is
`
`a
`
`schematic diagram showing av vehicle
`
`headlight optical axis direction automatic adjusting system
`
`according to a first embodiment of the invention;
`
`Fig.
`
`2 is a cross section showing a headlight used in
`
`the first embodiment;
`
`Fig.3is adiagramshowingfilterregionscorresponding
`
`.to control modes in the first embodiment;
`
`Fig. 4 is a flowciiagram showing an optical axis control
`
`in the first embodiment;
`
`Fig.
`
`5
`
`is a timing diagram showing an operation of a
`
`comparativeexampleofen1opticalaxiscontrollnithevehicle
`
`headlight optical
`
`axis direction automatic
`
`adjusting
`
`system;
`
`Fig.
`
`6 is a timing diagram showing an operation of the
`
`first embodiment;
`
`Fig.
`
`7 is a timing diagram showing a transition state
`
`_ ofla control angle according to a pitch angle in the first
`
`11
`
`

`
`embodiment;
`
`Fig.
`
`8
`
`is
`
`a
`
`schematic’ diagram showing a vehicle
`
`headlight optical axis direction automatic adfiusting system
`
`according to a second embodiment of the invention;
`
`Fig. 9is a flow<diagram showing an optical axis control
`
`depending on various
`
`loading conditions
`
`in the second
`
`embodiment;
`
`Fig.10is agraphshowingaapredictionexpressionwhich
`
`is divided into two vehicle posture regions for calculating
`
`a pitch angle on the basis of a vehicle rear height value
`
`in the second embodiment;
`
`Fig.11is agraphshowingapuedictionexpressionwhich
`
`is divided into two vehicle posture regions for calculating
`
`the pitch angle on the basis of the vehicle rear height value
`
`in the second embodiment;
`
`Fig. 12 is a graph showing a prediction expression which
`
`is divided into two vehicle posture regions for calculating
`
`the pitch angle on the basis of a vehicle front height value
`
`in the second embodiment;’
`
`Fig. 13 is a graph showing three prediction expressions
`
`each of which is divided into two vehicle posture regions
`
`and one of which is selected based on outputs from sensors
`
`except
`
`for
`
`the vehicle height
`
`sensor
`
`in the
`
`second
`
`embodiment;
`
`Fig.l4 Msaflowdiagramshowinganopticalaxiscontrol
`
`according to a third embodiment of the invention;
`
`Fig.
`
`15
`
`is a graph showing both of’
`
`a prediction
`
`<1;
`J
`
`5)
`
`7
`
`~
`
`12
`
`€
`

`
`expression without
`
`consideration
`
`of
`
`system error
`
`information and.a prediction expression in which the system
`
`error information of an installation error of the vehicle
`
`height sensor is considered in the third embodiment;
`
`Fig.
`
`16
`
`is a graph showing both of
`
`a prediction
`
`expression without consideration of
`
`the
`
`system error
`
`information and a prediction expression in which the system
`
`error information when the inclination of the prediction
`
`expression is changed due to an error in spring constants
`
`of the front and rear suspensions is considered in the third
`
`embodiment;
`
`Fig. 17 is a graph showing five prediction expressions
`
`in which
`the
`system error
`information such
`as
`the
`installation error of
`the vehicle height sensor to the
`
`vehicle and various errors caused by other factors of the
`
`vehicle is considered in the third embodiment;
`
`Fig.
`
`18
`
`is
`
`a
`
`schematic diagram showing
`
`a whole
`
`construction of a vehicle headlight optical axis direction
`
`automatic adjusting system according to a fourth embodiment
`
`of the invention;
`
`Fig.
`
`19
`
`is
`
`a
`
`timing diagram for
`
`explaining an
`
`inconvenience that the vehicle is stopped riding onaablock
`
`or the like when no headlight optical axis adjustment
`
`is
`
`applied;
`
`fi
`
`Fig. 20 is a timing diagram showing a transition of a
`
`measured rear height according to a change in the speed of
`
`the vehicle, based on which the optical axis direction of
`
`1".
`
`//8
`
`13
`
`

`
`the headlight is adjusted in the fourth embodiment;
`
`Fig.2ljs aflowdiagramshowingaaprocedurefordealing
`
`with the case where the vehicle is stopped riding onéiblock
`
`or the like, executed by the in the fourth embodiment;
`
`Fig. 22 is a timing diagranlshowing a transition of each
`
`displacement according to the change in the vehicle speed,
`
`based on the flow diagram of Fig. 21;
`
`Fig.
`
`23 is a timing diagram showing an optical axis
`
`direction adjustment amount of the headlight of the vehicle
`
`which is corrected based on the flow diagram of Fig. 21 and
`
`an optical axis direction adjustment amount which is not
`
`corrected for comparison;
`
`Fig. 24 is a flow diagram showing a modification of the
`procedure for dealing with the case where the vehicle is
`
`stopped riding on a block or the like, executed by the CPU
`
`in a fifth embodiment of the present
`
`invention;
`
`Fig.
`
`25
`
`is
`
`a
`
`timing diagram for
`
`explaining an
`
`inconvenience occurring duringaaturn.of the vehicle without
`
`correction;
`
`Fig. 26 is a flow diagram showing a procedure for dealing
`
`with not only the case where the vehicle is stopped riding
`
`on a block or the like but also a case where the vehicle is
`
`turning, by the CPU in a sixth embodiment; and
`
`Fig. 27 is a timing diagram showing an optical axis direction
`
`adjustment amounts, one when the turn state is determined
`
`based on the flow diagram of Fig. 26 and the other when the
`
`turn state is not determined.
`
`14
`
`

`
`DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
`
`The present invention will be described in detail with
`
`reference to various embodiments;
`
`in which the same or
`
`similar reference numerals designate the same or similar
`
`parts and steps.
`
`(First Embodiment)
`
`Referring first to Fig. 1, a front (front—whee1) height
`
`sensor11F‘isattachedtozafrontsuspensionprovidedbetween
`
`a front axle and a vehicle“chassis on a driver's seat side
`
`or a front passenger seat side. A rear (rear—wheel) height
`
`sensor llR is attached to a rear suspension provided between
`
`the rear axle and the vehicle chassis on the driver's seat
`
`side or the rear passenger seat side.
`
`A front height value
`
`(a displacement of the vehicle height on the front wheel
`
`side) HF and a rear height value (a displacement of
`
`the
`
`vehicle height on the rear wheel side) HR as relative
`
`displacements (displacements of the vehicle height) between
`
`the respective axles on the front and rear wheel sides and
`
`the vehicle chassis supplied from the height sensors 11F and
`
`11R, and various sensor signals of wheel speed pulses and
`the like from a wheel speed sensor 12 which is mounted as
`
`a vehicle speed sensor on the vehicle side and is used for
`
`known TRC and ABS controls and the like are supplied to an
`
`ECU (Electronic Control Unit) 20. For convenience, the ECU
`
`20 and the wheel speed sensor 12 are illustrated outside of
`
`the vehicle.
`
`The ECU 20 is a logical operating circuit comprising
`
`15
`
`

`
`a CPU 21 as a known central processing unit, a ROM 22 in which
`
`control programs are stored,
`
`a RAM 23 for storing various
`
`data,
`
`a B/U (back—up) RAM 24, an input/output circuit 25,
`
`and a bus line 26 connecting these elements.
`
`Output signals from the ECU 20 are supplied to actuators
`
`35R and 35L of right and left headlights 30R and 30L of the
`
`vehicle,therebyadjustingtheopticalaxisdirectnnlofthe
`
`right and left headlights 3012 and 301, as will be described
`
`hereinlater. The various sensor'signals fromtfluawheel speed
`
`sensor 12 and the like are used for determining the mode of
`
`the vehicle,
`
`such
`
`as
`
`stop mode,
`
`acceleration mode,
`
`deceleration mode, and constant speed mode.
`
`As shown in Fig. 2,
`
`the headlight 30L (BOR)
`
`includes
`
`a lamp 31, a reflector 32 for fixing the lamp 31, a. supporting
`
`member 33 of a rod shape for-supporting the reflector 32
`
`swingably in the directions shown by the arc arrow, a movable
`
`member
`
`34 having also a
`
`rod shape,
`
`for supporting the
`
`reflector 32, and the actuator 35L (35R) such as a stepping
`
`motor or a DC motor for driving the movable member 34 in the
`
`directions shown by the double-headed arrow.
`
`The movable
`
`member 34 is driven in the back and forth directions by the
`
`actuator 35L (35R) so that the reflector 32 is vertically
`
`inclined about
`the end of
`the supporting member 33 as a
`fulcrum only by an actuator driving angle (target optical
`
`axis direction adjusting angle) Ga which will be described
`
`hereinlater,
`
`thereby adjusting the optical axis direction
`
`of the headlight 30L (3OR). The optical axis direction of
`
`16
`
`

`
`the headlight 30L (30R) is initially set on the assumption
`
`that one driver is on the vehicle.
`
`The pitch angle 9p[°] as an inclination angle in the
`
`longitudinal direction of the vehicle to a preset reference
`
`plane is calculated by the following equation on the basis
`
`of the front height value HF and the rear height value HR
`
`sent from the height sensors 11F and 11R among the various
`
`sensor signals of the vehicle supplied to the ECU 20.
`
`Lw
`
`denotes a wheel base (distance between the axles) between
`
`the front and rear wheels.
`
`ep = tan"1,{ (HF - HR)./Lw} '-
`
`In Fig. 3, the filter regions A, B, and C are illustrated
`
`that correspond to the control modes of the vehicle (stop
`mode,
`acceleration mode,
`TRC
`acceleration ‘mode,
`ABS
`
`deceleration mode, deceleration mode, constant speed mode)
`
`when the abscissa denotes vehicle speed V [km/h] and the
`
`ordinate indicates acceleration dV/dt
`
`[m/s3] obtained by
`
`differentiating the vehicle speed V.
`
`The filters are
`
`realized by either hardware for the height sensor signal (for
`
`example, smoothing ofga signal by a CR circuit) or software
`
`for the height sensor signalcnrthe pitch angle (for example,
`
`smoothing of a signal by the ECU by using moving average or
`
`standard deviation). The systenxuses the moving average for
`the pitch angle, which is advantageous from the viewpoint
`
`of cost since the ECU is originally provided therein.
`
`In the diagram of Fig. 3,
`
`the filter A corresponding
`
`to the stop mode is used when the vehicle speed V is lower
`"\
`
`,/ /)1 1;
`
`Jié’
`
`17
`
`

`
`than a few km/h (for example,
`
`2 [km/h]).q when the vehicle
`
`is stopped, a large changesfiithe pitch angle due to loading,
`unloading, or the like is expected.
`No filtering or very
`
`weak filtering is therefore performed so that the actuator
`
`is allowed to respond quickly to the change in the pitch
`
`angle.
`on the other hand, when the vehicle speed V is equal
`
`to or larger than a few km/h (for example, 2 [km/h]) and the
`
`acceleration dV/dt obtained by differentiating the vehicle
`speed V exceeds a preset threshold (such as i2 [m/s’]), the
`
`filter B corresponding to the acceleration mode or
`
`the
`
`deceleration mode is used. Since the change in the pitch
`
`no filtering or very weak filtering is
`angle is large,
`performed so that the actuator is allowed to respond quickly
`
`‘to the change in the pitch angle.
`
`In this embodiment, as will be described hereinlater,
`
`when the speed V of the vehicle is equal to or higher than
`
`[km/h]) and the acceleration dV/dt
`2
`a few km/h (such as
`obtained by differentiating the vehicle speed V exceeds a
`
`threshold (for example,
`
`i2 [m/s’])
`
`for determining the
`
`acceleration mode or the deceleration mode and further once
`
`exceeds a preset threshold (for example ilo [m/s’]) which
`
`can not be reached in the normal driving state, unless the
`
`constant speed driving state of the vehicle continues for
`
`a predetermined period (for instance, 0.5 [sec]) after that,
`
`the TRC acceleration mode at the time of the TRC control or
`
`the ABS deceleration mode at the time of the ABS control is
`
`18
`
`

`
`determined and the filtering B which is also used in the
`
`acceleration
`
`or
`
`deceleration mode
`
`is
`
`continuously
`
`performed.
`
`when the vehicle speed V is equal to or higher than a
`
`few km/h (such as
`
`2
`
`[km/h])
`
`and the acceleration dv/dt
`
`obtainedkurdifferentiatingthevehiclespeed\7islowerthan
`
`the preset threshold (for example,
`
`:2 [m/s’]),
`
`the filter
`
`C corresponding to the constant speed mode is used. Since
`
`it is generally expected that
`
`the pitch angle does not
`
`largely change, strong filtering is performed so as to remove
`
`high frequency components of a vibration at
`
`the time of
`
`driving and the change in the pitch angle due to unevenness
`
`of the road surface,
`
`thereby preventing the actuator from
`
`responding.
`
`The optical
`
`iaxis control
`
`routine is
`
`repetitively
`
`executed every 50 ms or so by the CPU 21.
`
`As shown in Fig. 4, initial setting is executed at step
`
`S101. After that, the routine advances to step S102 where
`
`varioussensorsignahsofthewheelspeedpulse,frontheight
`
`value HF, rear height value HR, and the like are read. At
`
`step S103 , whether or not the vehicle speed V calculated from
`
`the wheel speed pulse read at step S102 is lower than a preset
`
`threshold V6 is determined‘. The threshold V0 is set to, for
`
`example, 2 [km/h] as shown in Fig. 3. When the determination
`
`condition at step S103 is satisfied,
`
`that
`
`is, when the
`
`vehicle speed\7is lower than 2[km/h], the routine advances
`
`to step S104 where a
`
`flag Flag which will be described
`
`19
`
`

`
`hereinlater is set to "0". At step S105, a timer TB which
`
`will be described hereinlater is cleared to "0". At step
`
`S106,
`
`the stop mode is determined and the weak filtering A
`
`shown in Fig.
`
`3 is performed to the pitch angle 6p calculated
`
`by the equation.
`
`A pitch angle Gpf obtained by performing
`
`the weak filtering A to the pitch angle Bp
`
`follows
`
`a
`
`transition state of the actual pitch angle Sp to a certain
`
`extent.
`
`On the other hand, when the determination condition at
`
`step S103 is not satisfied, that is, when the vehicle speed
`
`V is higher than 2 [km/h], the routine advances to step S107
`
`where it is determined whether or not the absolute value of
`
`the acceleration dV/dt obtained by differentiating the
`
`vehicle speed V is equal to or lower than a preset threshold
`
`al.
`
`The threshold ml is set to, for example,
`
`i2 [m/sz] as
`
`shown in Fig. 3. when the determination condition at step
`
`S107 is not satisfied, that is, when the absolute value of
`
`the acceleration dV/dt exceeds the threshold ocl and is large,
`
`the routine advances to step S108 where it is determined
`
`whether or not the absolute value of the acceleration dV/dt
`
`is equal to or smaller than a threshold a2. The threshold
`a2 is set to the acceleration, for example, £10 [m/s’] as
`
`shown in Fig.
`
`3 which is preset so as not to be reached in
`
`the normal driving state. when the determination condition
`
`at step S103 is satisfied, that is, when the absolute value
`
`of the acceleration dV/dt
`
`is equal
`
`to or
`
`lower than the
`
`threshold a2,
`
`the routine advances to step 8109 where the
`
`15
`
`20
`
`

`
`time TB is cleared to "O". The routine progresses to step
`
`S110 where
`
`the acceleration tor deceleration mode
`
`is
`
`determined and the weak filtering B shown in Fig.
`
`3
`
`is
`
`performed to the pitch angle Gp calculated by the equation.
`
`Thepitchangle6pfobtainaibyperformingtheweakfiltering
`
`B to the pitch angle 6p follows the transition state of the
`
`actual pitch angle Sp to a certain extent in a manner similar
`
`to the case of the stop mode.
`
`\
`
`When the determination condition at step S108 is not
`
`satisfied,
`
`that
`
`is, when
`
`the
`
`absolute value of
`
`the
`
`acceleration dV/dt exceeds the threshold a2 and is large,
`
`the routine advances
`
`to step S111 where the flag Flag
`
`indicating that the absolute value of the acceleration dV/dt
`once exceeds the threshold a2 is set to "1". At step S112,
`
`the timer TB is cleared to "0".
`
`At step S113,
`
`the TRC
`
`acceleration mode at the time of the TRC control or the ABS
`
`deceleration mode at
`
`the time of
`
`the ABS control
`
`is
`
`determined and the weak filtering B shown in Fig.
`
`3
`
`is
`
`performed to the pitch angle 6p calculated by the above
`
`equation.
`
`The pitch angle Gpf obtained by performing the
`
`weak filtering B to the pitch angle 6p as described above
`
`follows the transition state of the actual pitch angle Sp
`
`to a certain extent in a manner similar to the stop mode.
`
`Effectiveness of using the thresholds al and d2 of two
`
`stages for the absolute value of the acceleration dv/dt in
`
`the determination for the control mode switching at steps
`
`S107 and S108 will now be described with reference to the
`
`21
`
`

`
`timing diagrams of Figs.
`
`5 and 6.
`
`As will be understood from Figs.
`
`5 and 6, at the time
`
`ofTRCcn:ABScontrol,theaccelerationdv/dt[m/s’]obtained
`
`