United States Patent
`
`[19]
`
`[11] Patent Number:
`
`4,870,545
`
`[45] Date of Patent:
`Hatanaka et al.
`Sep. 26, 1989
`
`[54] HEADLIGHT CONTROL APPARATUS FOR
`MOTORCYCLES
`
`[56]
`
`References Cited
`U.S. PATENT DOCUMENTS
`
`3,939,339
`4,024,388
`
`2/1976 Alphen ................................ .. 362/72
`5/1977 Skoff ................................... .. 362/72
`
`Primary Examz‘ner—Stephen F. Husar
`Attorney, Agent, or Firm—-Lyon & Lyon
`
`[57]
`
`ABSTRACT
`
`Method and apparatus are described for controlling the
`roadway illuminating position of a motorcycle head-
`light during cornering of the motorcycle by determin-
`ing a basic desired optical axis deflection angle for the
`headlight in response to the turning radius of the vehicle
`and, coincident
`therewith, correcting the deflection
`angle in accordance with the determined longitudinal
`position of the motorcycle along the roadway turning
`line.
`
`[75]
`
`Inventors: Kaoru Hatanaka; Hajirne Tabata,
`both of Saitama; Tooru Hasegawa,
`Tokyo; Yoshihiro Nakazawa,
`Saitama, all of Japan
`
`[73] Assignee:
`
`Honda Giken Kogyo Kabushiki
`Kaisha, Tokyo, Japan
`
`[21] Appl. No.: 257,215
`
`[22]
`
`Filed":
`
`Oct. 13, 1988
`
`Foreign Application Priority Data
`[30]
`Oct. 13, 1937 [JP]
`Japan ................................ 62-258548
`
`
`
`Int. Cl.4 . ... . .. .. . . . .. .... .. ..
`[51]
`[52] U.S. Cl.
`
`. . . .. . .. B62J 6/00
`....... 362/72; 362/66;
`315/82
`
`[58] Field of Search ....................... 362/37, 71, 72, 66,
`362/418, 428, 271, 272, 286; 315/79, 81, 82
`
`10 Claims, 4 Drawing Sheets
`
` 2
`
`TURNING
`
`""l‘l1‘c‘i'e‘“sa«soa
`
`---__..-.._-_
`
`1
`
`KOITO 103
`
`Koito Manufacturing v. Adaptive Headlam
`|PR2016-0007
`
`1
`
`KOITO 1033
`Koito Manufacturing v. Adaptive Headlamp
`IPR2016-00079
`
`

`
`US. Patent
`
`Sep.26, 1989
`
`Sheet 1 of4
`
`4,870,545
`
`OPTMALAXE
`CONTROL MOTOR
`
`THROTTLE
`SENSOR
`
`2
`
`

`
`US. Patent
`
`4,870,545
`
`
`
`/c-3.3.
`
`H
`
`32
`
`Ae(=Aeo)
`
`320‘
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`/
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`3
`
`

`
`U.S. Patent
`
`Sep. 26, 1989
`
`Sheet 3 of 4
`
`4,870,545
`
`START
`
`IIIIIIIIUNIIIII
`
`HANDLEBAR TURNING
`ANGLE SENSOR Bag
`
`VEHICLE SPEED
`SENSOR
`VSP
`
`40!
`
`402
`
`403
`
`404
`
`INC RADIUS
`PUTATION
`- V_5P
`R-K egg
`
`COMPUTATION OF BASIC OPTICAL AXIS omscnou .
`
`R-—-9
`
`
`.%”aII’I”
`SECTION
`
`F/G. 4.
`
`A90
`
`ouwur
`
`SENSING or GEAR POSITION
`
`ACCELERATOR opzume
`SENSOR am
`
`406
`
`407
`
`403
`
`409
`
`VEHICLE SPEED COMPUTATION
`
`9TH —-
`
`4
`
`

`
`U.S. Patent
`
`Sep. 26,1989
`
`Sheet 4 of4
`
`4,870,545
`
`FIXED TIME
`INTERRUPTION
`
`
`
`HANDLEBAR TURNING
`ANGLE SENSOR Gag
`
`
`
`502
`
`503
`
`504
`
`VEHICLE SPEED
`SENSOR VSP
`
`
`
`
`TURNING RADIUS
`COMPUTGEPN
`
`R=K E
`
`
`
` R—>
`COMPUTATION OF BASIC OPTICAL AXIS
`DEFLECTION.
`
`507
`
`VSP -->
`COMPUTATION OF HANDLEBAR TURNING
`
`
`ANGLE.
` 9’ag OUTPUT
`
`5
`
`

`
`1
`
`4,870,545
`
`HEADLIGHT CONTROL APPARATUS FOR
`MOTORCYCLES
`
`BACKGROUND OF THE INVENTION
`
`The present invention relates to a headlight apparatus
`for motorcycles and, more particularly, to a headlight
`apparatus that deflects the optical axis of the headlight
`in accordance with the turning radius of a vehicle when
`the vehicle rounds a curve or turns a corner, or the like.
`A conventional headlight deflection control appara-
`tus for motorcycles is known in the prior art as dis-
`closed in, for example, Laid-Open Japanese Patent No.
`Sho. 62-96148. This prior art, the disclosure of which is
`incorporated herein by reference, is designed to com-
`pute a turning radius from the vehicle speed and an
`inclination angle of the vehicle body, to compute an
`adjusted angle of optical axis of the headlight from the
`turning radius, and to turn the headlight by this adjusted
`angle of optical axis to the direction to which the vehi-
`cle body is going to turn, thereby improving light distri-
`bution to the turning path of the vehicle.
`Generally, when rounding a corner, a motorcycle
`rider has a tendency to view the apex of the corner
`when he has come to the entrance of the corner, the exit
`of the corner when at a midway location therein, and
`the traffic condition ahead as in the forward straight-
`away when at the exit of the corner. However, the prior
`art described above has the problem that the headlight
`is only rotated by the aforesaid angle of the optical axis
`to the direction of turn of the vehicle body and, accord-
`ingly, light distribution to the areas within the rider’s
`view at the entrance, midway and exit of the corner
`cannot be obtained.
`The present invention, accordingly, has as a general
`objective to solve the above-mentioned problems of the
`prior art. It further seeks to provide a headlight control
`apparatus for motorcycles which has good light distri-
`bution characteristics in the direction of turning when
`the vehicle rounds a corner, and enables light distribu-
`tion to the region of the rider’s visual confirmation at
`each of the entrance, midway and exit positions of the
`corner.
`
`SUMMARY OF THE INVENTION
`
`According to the present invention there is provided
`a headlight optical axis deflection control apparatus for
`motorcycles comprising a vehicle speed sensing means;
`a handlebar turning angle sensing means; means for
`computing a turning radius for the vehicle from the
`vehicle speed and the handlebar turning angle sensed by
`said aforementioned sensing means, and computing
`from said turning radius a basic optical axis deflection
`angle at which the headlight illuminates a turning line;
`an optical axis control means for deflecting the optical
`axis of said headlight on the basis of said basic optical
`axis deflection angle; a corner position sensing means
`for sensing, from the running state of the vehicle, in
`which position of entrance, midway and exit the vehicle
`is present; and a correcting means for correcting said
`basic optical axis deflection angle to a greater value
`when the entrance position of a corner has been sensed
`by said comer position sensing means, and for correct-
`ing said basic optical axis deflection angle to a smaller
`value when the exit position of the corner has been
`sensed.
`In the aforementioned headlight apparatus for motor-
`cycles, the computing means computes the turning ra-
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`dius from the vehicle speed and the handlebar turning
`angle and also computes a basic headlight optical axis
`deflection angle from the turning radius. When the
`entrance position of the corner has been sensed by the
`corner position sensing means,
`the basic optical axis
`deflection angle is corrected to a greater value by a
`correcting means; and when the exit position of corner
`has been sensed, the basic optical axis deflection angle is
`corrected to a smaller value.
`For a better understanding of the invention, its oper-
`ating advantages and the specific objectives obtained by
`its use, reference should be made to the accompanying
`drawings and description which relate to a preferred
`embodiment thereof.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`FIG. 1 is a block diagram illustrating schematically a
`motorcycle headlight control apparatus according to
`the present invention;
`FIG. 2 is an explanatory view illustrating the running
`state of a vehicle in the vicinity of the entrance position
`of a comer;
`FIG. 3 is an explanatory view illustrating the direc-
`tion of headlight deflection during riding at positions
`near the entrance, midway and exit of the corner, re-
`spectively;
`FIG. 4 is a flowchart illustrating the steps of opera-
`tion of the headlight control apparatus of the present
`invention; and
`FIG. 5 is a flowchart illustrating the steps operation
`of a second embodiment of the present invention.
`DESCRIPTION OF A PREFERRED
`EMBODIMENT
`
`FIG. 1 is a schematic block diagram illustrative of a
`headlight apparatus for motorcycles pertaining to one
`embodiment of the present invention. As shown in this
`drawing figure, the headlight apparatus of a motorcycle
`1 is provided with a vehicle speed sensor (the vehicle
`speed sensing means) 2 for sensing the vehicle speed
`Vsp; a steering wheel turning angle sensor (the handle-
`bar turning angle sensing means) 3 for sensing the han-
`dlebar turning angle Gag; a computing section (the
`computing means) 5 for computing the turning radius R
`of the vehicle from the vehicle speed V512 and the han-
`dlebar turning angle Gag that have been sensed by the
`sensors 2 and 3, and also computes from the turning
`radius R a basic optical axis deflection angle A90 at
`which the headlight 4 illuminates the turning line; an
`optical axis control motor (the optical axis control
`means) 6 for deflecting the optical axis 4a of the head-
`light (see FIG. 2) on the basis of the basic optical axis
`deflection angle A90; a corner position sensing section
`(the corner position sensing means) 7 for sensing from
`the running state of the vehicle in which region of the
`comer,
`i.e., entrance, midway or exit, the vehicle is
`present; and a correcting section (the correction means)
`8 for correcting the basic optical axis deflection angle
`A60 to a greater value when the entrance position of
`the corner has been sensed by the corner position sens-
`ing section 7, and also for correcting the basic optical
`axis deflection angle A60 to a smaller value when the
`exit position of the corner has been sensed. The comput-
`ing section 5, the corner position sensing section 7, and
`the correcting section 8 constitute the control unit 9. To
`the input terminal of the computing section 5, output
`signals from the vehicle speed sensor 2 and the handle-
`
`6
`
`

`
`3
`bar turning angle sensor 3 as well as an output signal
`from the throttle sensor 10 are transmitted.
`The operation of the above-described first embodi-
`ment of the present invention is explained with refer-
`ence to FIG. 2 to FIG. 4. As shown in FIG. 4, fixed
`time interruption is effected (Step 401); the handlebar
`turning angle sensor 3 senses the handlebar turning
`angle, Gag (Step 402); the vehicle speed sensor 2 senses
`the vehicle speed, V31: (Step 403); the computing sec-
`tion 5 computes the turning radius R (R =K.Vsp/Gag)
`of the vehicle from the vehicle speed Vsp, and the han-
`dlebar turning angle, ag (Step 404); and computes, from
`the turning radius R, the basic optical deflection angle,
`A90, at which the headlight illuminates the turning line
`11 (See FIG. 3) (Step 405); and this optical axis deflec-
`tion angle Aeo is outputted (Step 406).
`Thereafter, a gear position sensor, which is not illus-
`trated, senses the gear position (Step 407), and a throttle
`sensor 10 senses the accelerator opening, OTH (Step
`408). The vehicle speed computing section (not illus-
`trated), which is a part of the aforementioned corner
`position sensing section 7, computes the vehicle speed,
`Vsp’, from the gear position and the accelerator open-
`ing, em (Step 409). The comer position sensing section
`7 determines whether or not the vehicle speed, Vsp’, is
`greater than the accelerator opening 9751, at Step 410
`and whether or not the vehicle speed, Vsp', is smaller
`than the accelerator opening, 97;], at Step 411. Com-
`parison between the vehicle speed, Vsp’, and the accel-
`erator opening 673, is made at a voltage value corre-
`sponding to each value, for example.
`When an answer is “Yes” at Step 410, that is, when
`the engine brake is on, the corner position sensing sec-
`tion 7 outputs to the correcting section 8 a signal which
`denotes that the vehicle is near the entrance position 31
`of the corner 12 as shown in FIGS. 2 and 3, which, in
`turn, outputs to the computing section 5 (Step 412) a
`corrected value (+a) for correcting the aforesaid basic
`optical axis deflection angle A60 to a greater value.
`Consequently, the computing section 5 outputs the opti-
`cal axis deflection angle, AG(A9=AGo +0.), to the
`optical axis control motor 6 (Step 414). At this time, the
`optical axis 4a of the headlight 4, as shown in FIGS. 2
`and 3, turns inwardly in the direction of turn through
`the above-mentioned optical axis deflection angle
`A9(A9=A9o +a), from the tangential direction 31a
`to the direction 31b of the turning line 11 at the above-
`mentioned entrance position 31. Therefore, the head-
`light 4 illuminates the rider’s range of visibility near the
`entrance position 31, that is, the range of visibility near
`the apex of the corner 12.
`When the answer at Step 410 is “No”, proceed to the
`aforementioned Step 411, and when the answer at Step
`411 is “No”, that is, when the engine brake is off and the
`vehicle is not accelerated, the corner position sensing
`section 7 outputs to the correction section 8 a signal
`which indicates that, as shown at 32 in FIG. 3, the
`vehicle is near the midway position of the corner 12. At
`this time, the correction section 8 outputs a corrected
`value 0 to the computing section 5. Consequently, the
`computing section 5 outputs the optical axis deflection
`angle, A9(Ae= A60), to the optical axis control motor
`6 (Step 414). At this time, the optical axis 4a of the
`headlight 4, as shown in FIG. 3, turns inwardly in the
`direction of turn through the aforementioned optical
`axis deflection angle, A9(A9=A6o) from the tangen-
`tial direction 32a to the direction 32b of the turning line
`11 at the aforesaid midway position 32 Therefore, the
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`rider’s view in the vicinity of the midway position 32,
`that is, a View 35 in the vicinity of the exit of the corner
`12, are illuminated by the headlight 4.
`When the answer at Step 411 is “Yes”, that is, when
`the vehicle is under acceleration, the corner position
`sensing section 7 outputs to the correcting section 8 a
`signal which, as shown in FIG. 3, denotes that the vehi-
`cle is near the exit position 33 of the corner 12. The
`correcting section 8, in turn, outputs to the computing
`section 5 a corrected value (—a) for correcting the
`aforementioned basic optical deflection angle A90 to a
`smaller value (Step 413). In consequence, the comput-
`ing section 5 outputs the optical axis deflection angle,
`A9(A6=A9o —oL), to the optical axis control motor 6
`(Step 414). At this time the optical axis 4a of the head-
`light 4, as shown in FIG. 3, turns through the aforemen-
`tioned optical axis deflection angle A6(A6= A60 — a)
`from the tangential direction 33a of the turning line 11
`at the above-mentioned exit position 33, inwardly in the
`direction of turn, to the direction 33b so that the rider’s
`view 36 in the vicinity of the entrance position 33 is
`illuminated by the headlight 4. At the conclusion of the
`procedure the aforementioned optical axis deflection
`angle A9 is reset at Step 415.
`A headlight control apparatus for motorcycles ac-
`cording to a second embodiment of the present inven-
`tion is described with reference to FIG. 5. The second
`embodiment differs from the first embodiment de-
`scribed in the method by which sensing is effected by
`the aforementioned corner position sensing section 7 of
`the entrance, midway and exit positions of the corner,
`but is identical to the first embodiment in other respects.
`FIG. 5 is a flowchart explaining the steps of operation
`of the second embodiment. Steps 501 to 506 in this
`drawing are effected in a manner similar to that of Steps
`401 to 406 in the FIG. 4 embodiment as described
`above. As shown in the flowchart, the handlebar turn-
`ing angle set value computing section (not illustrated)
`which is a part of the aforesaid corner position sensing
`section 7 computes the handlebar turning angle set
`value, Gag’, which is a function of the vehicle speed,
`V5p’(Step 507), outputting the handlebar turning angle
`set value, Gag’ (Step 508). This handlebar turning angle
`set value, Bag’, is used to determine whether or not the
`vehicle, after passing the entrance position of the cor-
`ner, has entered a midway position, that is whether or
`not the vehicle is turning a corner.
`At Step 509, is determined whether or not the handle-
`bar turning angle, Bag, is greater than the handlebar
`turning angle set value Gag’. When the answer is nega-
`tive (No), the corner position sensing section 7 outputs
`to the correcting section 8 a signal which denotes that
`the vehicle is present in the vicinity of the entrance
`position 31 and the correcting section 8 will, in turn,
`output to the computing section 5 a corrected value
`(+a) to correct the aforementioned basic optical axis
`deflection angle A90 to a greater value (Step 510). As a
`result, therefore, the computing section 5 outputs the
`optical axis deflection angle, A6(A9= A60 +00, to the
`optical axis control motor 6 similarly to the case of the
`aforesaid first embodiment (Step 511).
`When the answer at Step 509 is affirmative (Yes), that
`is, when the vehicle is rounding a corner, the above-
`described throttle sensor 10 senses the accelerator open-
`ing, 61-H(Step 512), and, effecting a fixed time interrup-
`tion, senses a variation, A673,
`(A617; =67}; (m)
`-971; (m -1)), of the accelerator opening 97;; which
`is the difference between the accelerator opening, 917;
`
`7
`
`

`
`5
`(m —— 1), previously sensed by the fixed time interrup-
`tion and the accelerator opening, an; (m), sensed this
`time (Step 513), thus determining whether or the not the
`variation, A9711, of the accelerator opening, 97;; (Step
`514) is increasing.
`When the answer at Step 514 is negative (No), that is,
`when the vehicle is rounding a corner, but not under
`acceleration, the corner position sensing section 7 out-
`puts to the correcting section 8 a signal denoting that
`the vehicle is near the midway position 32 of the corner
`12, and the correcting section 8 outputs the corrected
`value 0 to the computing section 5. As a result, the
`computing section 5 outputs the optical axis deflection
`.angle AG(A9=A8o) to the optical axis control motor 6
`similarly to the first embodiment described above (Step
`511).
`When the answer at Step 514 is affirmative (Yes), that
`is, when the vehicle is under acceleration during round-
`ing a comer, the corner position sensing section 7 out-
`puts to the correcting section 8 a signal which denotes
`the presence of the vehicle in the vicinity of the exit
`position 33 of the corner 12, which, in turn, outputs to
`the computing section 5 a corrected value (—a) for
`correcting the aforementioned optical axis deflection
`angle A90 to a smaller value (Step 515). Consequently,
`the computing section 5 will output the optical axis
`deflection angle; A9(A9=A9o —a), to the optical axis
`control motor 6 similarly to the first embodiment (Step
`514). And the aforementioned optical axis deflection
`angle AG is reset at Step 516.
`As described in detail above, according to the motor-
`cycle headlight control apparatus of the present inven-
`tion, the computing means computes the turning radius
`from the vehicle speed and the handlebar turning angle,
`and also computes from the turning radius the basic
`optical axis deflection angle for the projection of head-
`light beam onto the turning line. This arrangement,
`therefore, improves the light distribution characteristics
`in the direction of turn during cornering. The handlebar
`turning angle sensing means senses, from the running
`state of the vehicle, in which position of the comer,
`entrance, midway or exit, the vehicle is present. The
`correcting means accordingly corrects the basic optical
`axis deflection angle to a greater value when the en-
`trance position of the corner has been sensed by the
`corner position sensing means, and, alternatively, cor-
`rects the basic optical axis deflection angle to a smaller
`value when the exit position of the corner has been
`sensed, thereby enhancing light distribution to the area
`the rider views at each position of entrance, midway
`and exit of the corner.
`It should be further understood that, although the
`preferred embodiments of the invention have been illus-
`trated and described herein, changes and modifications
`can be made in the described arrangements without
`departing from the scope of the appended claims.
`We claim:
`1. A motorcycle headlight optical axis deflection
`control apparatus comprising:
`means for determining the turning radius of said mo-
`torcycle;
`means for computing from said turning radius a basic
`optical axis deflection angle at which said headlight
`illuminates a roadway turning line;
`
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`control means operatively connected to said motor-
`cycle headlight for deflecting the optical axis of
`said headlight in accordance with the computed
`basic optical axis deflection angle;
`'
`means for determining the longitudinal position of
`said motorcycle along said roadway turning line;
`and
`means for correcting the deflection of said headlight
`optical axis in response to the position of said mo-
`torcycle along said roadway turning line.
`2. The control apparatus according to claim 1 in
`which said turning radius determining means comprises:
`means for sensing vehicle speed;
`means for sensing the turning angle of the motorcy-
`cle; and
`means for computing the turning radius of said mo-
`torcycle in response to the sensed values of vehicle
`speed and motorcycle turning angle.
`3. The control apparatus according to claim 2 in
`which said turning angle sensing means comprises
`means for sensing the angular position of a steering
`wheel of said motorcycle.
`4. The control apparatus according to claim 3 in
`which the angular position of said steering wheel
`is
`controlled by motorcycle handlebars. and said turning
`angle sensing means comprises means for sensing the
`position of said handlebars.
`5. The control apparatus according to claim 1 in
`which said headlight optical axis deflection angle is
`corrected at least at the entrance, and at the exit of said
`turning line.
`6. The control apparatus according to claim 5 in
`which said headlight optical axis deflection angle is
`corrected at a position intermediate the entrance and
`exit positions of said turning line.
`7. The control apparatus according to claim 5 in
`which said basic optical deflection angle is increased
`when said entrance position is sensed and decreased
`when said exit position is sensed.
`8. A method of controlling the optical axis deflection
`angle of a motorcycle headlight comprising the steps of:
`determining the turning radius of the motorcycle;
`computing a basic optical axis deflection angle at
`which said headlight illuminates a roadway turning
`line;
`determining the position of the motorcycle along said
`roadway turning line; and
`positioning the headlight of the motorcycle headlight
`in response to the computed basic optical axis de-
`flection angle as
`corrected in response to the position of the motorcy-
`cle along said roadway turning line.
`9. The method according to claim 8 including the
`steps of sensing the speed of said motorcycle and the
`turning angle thereof and computing the basic optical
`deflection angle in response to the sensed speed and
`turning angle of said motorcycle.
`10. The method according to claim 9 including the
`steps of increasing the optical deflection angle of said
`headlight when said motorcycle is at the entrance of
`said roadway turning line and reducing said optical
`deflection angle when said motorcycle is at the exit
`thereof.
`ill
`*
`3|!
`4!
`=l=
`
`8