Procedure for adjusting a main headlight of a motor vehicle

Abstract

The invention relates to a method (12) for adjusting a main headlight (10) of a motor vehicle (1), - in which the motor vehicle (1) is positioned in front of a wall (19), - in which a laser (21) is arranged on a rear wheel (5) of the rear axle (4) and a reference line (23) is generated on the wall (19) with laser light (22), - in which a reference feature (24) is generated on the wall (19) by means of the respective main headlight (10) headlight light (20), - where a longitudinal distance (28) is measured between a vehicle reference point (29) and the wall (19), - in which, depending on the measured longitudinal distance (28), an angular deviation (30) between the reference line (23) and a target position (27) of the reference feature (24), which the reference feature (24) has on the wall (19) at the measured longitudinal distance (28) and at a target alignment of the main headlight (10), is calculated, - where a digital angle correction is activated on the main headlight (10) according to the calculated angle deviation (30), the alignment of the main headlight (10) is adjusted so that the reference feature (24) on the wall (19) lies on the reference line (23), and the angle correction is deactivated.

Description

[0001] The present invention relates to a method for adjusting a main headlight of a motor vehicle.

[0002] A motor vehicle typically has two headlights at its front, one on each side. These headlights can produce at least low beam and high beam. The primary beam direction of the headlights should ideally be aligned parallel to the vehicle's driving axis when traveling straight ahead. Due to additional functions in modern vehicles, such as road illumination using the headlights, precise alignment of the headlight beam direction parallel to the driving axis is of particular importance.Due to unavoidable tolerances, for example, a body twist angle is largely unavoidable, so that a vehicle longitudinal axis determined by the vehicle body can deviate more or less from the driving axis, which is particularly noticeable in the headlight beam emitted by the main headlights at a greater distance in front of the vehicle.

[0003] There is therefore a need to be able to adjust the main headlights as precisely as possible with reasonable effort, especially during maintenance, whereby in this case a lateral adjustment is preferably concerned, in which a main beam direction of the main headlight is set perpendicular to the longitudinal direction and horizontally, which is possible in particular by rotating the main headlight about a vertical axis.

[0004] From CN 1 17 740 340 A it is known to measure the longitudinal distance between the vehicle and the wall to determine a target position of the reference feature with respect to the reference line generated by a loader arranged at the front wheel.

[0005] From DE 10 2014 003 370 A1 it is known to attach a laser light source to a rear wheel of a motor vehicle for the purpose of checking lighting units of a motor vehicle.

[0006] From DE 10 2014 113 070 B4, an adjustment device for aligning a component is known, comprising a radiation source for generating a light beam parallel to an alignment axis of the component and a light detection device that detects the light beam and determines the actual position of the light beam relative to a reference surface, wherein a detection device determines a deviation of the actual position from a target position. A control signal for aligning the component using the determined deviation can then be provided via an information interface.

[0007] From DE 10 2016 001 186 A1 a headlight adjustment device is known which works with adjustment plates that must be mounted on the two wheels on one side of a headlight to be adjusted.

[0008] From KR 10 2022 0 159 760 A, a laser device for measuring vehicle width is known, which can be attached to a vehicle door or to various parts of a wheel, such as the rim, bearing, disc, or hub. The laser device emits a horizontal beam with a predetermined width on both sides of the vehicle.

[0009] From DE 100 23 328 B4, an adjustment device for an optical aiming device with a reflector is known, which is used for adjusting the headlights of a motor vehicle. This adjustment device has a laser and a vertical adjustment device for adjusting the reflector. A height-adjustable aperture is arranged between the aiming device and the laser, through which the laser beam is guided to the reflector and, after reflection, back through the aperture. The laser is positioned in a specific area of ​​the vehicle at a defined height and can emit the light beam at different vertical angles.

[0010] The present invention addresses the problem of providing a method for adjusting a main headlight of a motor vehicle which is characterized by particularly high precision and can, in particular, eliminate a body twist angle.

[0011] This problem is solved according to the invention by the subject matter of the independent claim. Advantageous embodiments are the subject matter of the dependent claims.

[0012] The invention is based on the consideration that the headlight beam emitted from the respective main headlight towards a wall has a reference feature, or creates a reference feature on the wall, which, when the main headlight is in its intended alignment (i.e., optimally aligned), has a target position on the wall that has a predetermined relative position with respect to a vehicle reference point projected onto the same wall. Furthermore, the invention utilizes the knowledge that the target position, the vehicle reference point, and the relative position on the wall depend on the longitudinal distance between the vehicle and the wall. According to the invention, an angular deviation is calculated as a function of the actual longitudinal distance, which, when the main headlight is in its intended alignment, creates or corresponds to a target distance between the target position and the vehicle reference point on the wall.A digital angle correction of the main headlight by this angular deviation reduces the target distance, which depends on the longitudinal distance, to zero, so that the reference feature and the vehicle reference point on the wall coincide or align. If the actual alignment of the main headlight deviates from the target alignment, a gap exists between the reference feature and the vehicle reference point on the wall. The main headlight can then be manually and mechanically adjusted until the reference feature and the vehicle reference point on the wall coincide or align.

[0013] The method according to the invention is characterized in that no predetermined target longitudinal distance between the wall and the vehicle needs to be maintained for adjusting the main headlight, which greatly simplifies the adjustment process.

[0014] Specifically, the invention proposes that, for adjusting a motor vehicle's headlight, the vehicle is positioned in front of a wall such that a front axle of the vehicle is located between the wall and a rear axle. The headlight can then shine its beam onto the wall. A laser, positioned at a predetermined location on a rear wheel of the rear axle, can then be directed at the wall, creating a preferably vertical reference line. This reference line represents the aforementioned vehicle reference point. The headlight can then shine its beam onto the wall, creating an optical reference feature or generating an optical reference feature on the wall.The procedure involves determining a longitudinal distance between a vehicle reference point and the wall, based on the vehicle's actual position in front of the wall. From this measured longitudinal distance, and taking into account the geometric positions or position data of the headlights, laser, and vehicle reference point, an angular deviation between the reference line and a target position of the reference feature, dependent on the longitudinal distance, can be calculated. This target position is assumed by the reference feature on the wall at the measured longitudinal distance when the headlights are optimally adjusted or aligned, i.e., in their target orientation. This angular deviation represents the target distance between the reference feature and the reference line mentioned above, which depends on the longitudinal distance and is achieved when the headlights are optimally adjusted or aligned, i.e., in their target orientation.After determining the angular deviation, a digital angle correction of the main headlight can be activated using the calculated angle value. This reduces the target distance to zero, ensuring that the reference feature lies on the reference line when the main headlight is optimally adjusted and aligned, i.e., in its target alignment. If the main headlight is not optimally adjusted, the actual alignment deviates from the target alignment. This results in a visible gap between the reference feature and the reference line on the wall. This gap is horizontal and oriented perpendicular to the wall's longitudinal distance; it can also be referred to as the transverse distance. Consequently, the main headlight's alignment can be adjusted to eliminate this transverse distance.With the lateral offset eliminated, the lateral offset between the reference line and the reference feature is zero. In other words, the reference feature then lies on the reference line. The digital angle correction can then be deactivated again.

[0015] According to an advantageous embodiment, the laser can be positioned at the respective rear wheel such that the laser light is perpendicular to the rear axle. This eliminates any body roll angle. The reference line then represents the laser position on the wall, i.e., a lateral vehicle boundary defined by the rear wheel.

[0016] Modern passenger cars, preferably rear-wheel drive, have a toe angle on the rear wheels, preferably toe-in, which stabilizes handling, especially in rear-wheel drive vehicles. With toe-in, the wheels roll towards each other when driving forward, so that their directions of rotation converge in front of the vehicle.

[0017] According to an advantageous embodiment, the calculation of the angular deviation can take into account the toe angle of the rear wheel. The toe angle is predetermined for the respective vehicle model and can therefore be considered computationally, essentially as a target toe angle. This improves the accuracy of the headlight adjustment.

[0018] In an alternative embodiment, the laser can be positioned at the respective rear wheel such that the laser light is perpendicular to a rotational axis of that wheel. This means the reference line is already corrected for the rear wheel's toe angle. This simplifies the calculation of the angular deviation. Furthermore, this takes the actual toe angle into account, essentially as the real-time toe angle, which improves the overall accuracy of the headlight alignment.

[0019] The vehicle is conveniently equipped with a left and a right headlight. To adjust the left headlight, the laser is positioned at the left rear wheel. To adjust the right headlight, the laser is positioned at the right rear wheel. The two headlights can generally be adjusted sequentially or simultaneously using two lasers.

[0020] According to another advantageous embodiment, the respective main headlight can be configured for operation in an adjustment mode in which the emitted headlight light projects an adjustment image onto the wall, featuring a reference feature. Such an adjustment image is characterized by a particularly distinct reference feature, which facilitates adjustment and also enables greater accuracy. The adjustment image can differ fundamentally from a conventional image for illuminating the vehicle's surroundings, which is generated using the headlight light in a normal operating mode and corresponds, for example, to a low beam or high beam. It can be particularly advantageous for the adjustment image to be configured as a crosshair or to feature a crosshair as a reference feature. Such a crosshair represents a particularly distinct reference feature.

[0021] In the present context, a “configuration” is synonymous with a “design” and / or “setup” and / or “programming”, so that the phrase “configured so that” is synonymous with the phrase “designed and / or set up and / or programmed so that”.

[0022] According to an advantageous embodiment, the laser position can be used as a vehicle reference point. It is also conceivable to use the position of the respective main headlight on the vehicle as a vehicle reference point. Likewise, any other stationary point on the vehicle can be used as a vehicle reference point, provided that the geometric position data in relation to the main headlight and the respective rear wheel or the laser position are known. If the laser position is used as a vehicle reference point, an advantageous embodiment allows the laser to be configured for distance measurement using the laser light.

[0023] The laser mounted on the rear wheel can then be used to measure the longitudinal distance between the laser position and the wall. This simplifies the calculation of the angular deviation.

[0024] Optionally, the laser can be configured to emit laser light perpendicular to the rear axle for measuring the longitudinal distance and perpendicular to the rear wheel's axis of rotation for generating the reference line. This ensures that the longitudinal distance measurement is independent of the track angle, while the reference line generation takes the track angle into account. This results in a particularly accurate adjustment.

[0025] Alternatively, the laser can be configured to emit laser light perpendicular to the axis of rotation for measuring the longitudinal distance and generating the reference line, with the measured longitudinal distance corrected by the track angle of the rear wheel, so that the corrected longitudinal distance is used to calculate the angular deviation. This simplifies the design and / or arrangement of the laser.

[0026] In another embodiment, the vehicle can be positioned in front of the wall such that a minimum distance is maintained between the wall and the vehicle's reference point, which is at least as large as the distance between the front and rear axles. Preferably, the minimum distance is at least twice the distance between the front and rear axles. Maintaining a predetermined minimum distance improves the accuracy of the headlight adjustment.

[0027] Further important features and advantages of the invention will become apparent from the dependent claims, the drawings and the associated description of the figures based on the drawings.

[0028] It is understood that the features mentioned above and those to be explained below can be used not only in the combinations specified, but also in other combinations or individually, without departing from the scope of the invention as defined by the claims. Components of a higher-level unit, such as a device, apparatus, or arrangement, mentioned above and those to be mentioned below, which are designated separately, can form separate parts or components of this unit or be integral areas or sections of this unit, even if this is depicted differently in the drawings.

[0029] Preferred embodiments of the invention are shown in the drawings and are explained in more detail in the following description, wherein identical reference numerals refer to identical or similar or functionally identical components.

[0030] They show, schematically, Fig. 1. A highly simplified schematic representation of a motor vehicle during the adjustment of a main headlight, Fig. 2. A flowchart of a procedure for adjusting the main headlight.

[0031] Accordingly Fig. A motor vehicle 1 or vehicle 1 comprises a front axle 2 with two front wheels 3, a rear axle 4 with two rear wheels 5, and a body 6. The body 6 defines a longitudinal axis 7, and the rear axle 4 defines a driving axis 8 of the vehicle 1, perpendicular to the rear axle 4. In an ideal vehicle 1, the longitudinal axis 7 and the driving axis 8 coincide. However, due to manufacturing tolerances, a body twist angle 9 can occur, by which the body 6 is twisted with respect to a vertical axis relative to an optimally aligned rear axle 4. The body twist angle 9 is also located between the longitudinal axis 7 and the driving axis 8.

[0032] Vehicle 1 is also equipped with two main headlights 10 at its front end. Ideally, i.e., when each main headlight 10 is optimally aligned with vehicle 1, it has a target alignment. Furthermore, each main headlight 10 has a main beam direction 11, which, in the target alignment, can be parallel to the driving axis 8. In particular, settling or repairs can cause each main headlight 10 to change its alignment with respect to vehicle 1, so that the main headlights 10 must be readjusted, especially during maintenance intervals. Here, we consider lateral adjustment, i.e., adjustment with respect to a horizontal direction perpendicular to the vehicle's longitudinal direction 7. Fig. 2 comprises a method 12 for adjusting such a main headlight 10 of the motor vehicle 1 several steps 13 to 18, which are explained in more detail below.

[0033] In step 13, the vehicle 1 is positioned, for example in a workshop or on a test bench, in front of a wall 19 such that the front axle 2 is located between the wall 19 and the rear axle 4. This means that the headlights 10 are facing the wall 19 and can emit headlight beam 20 onto the wall 19. The wall 19 is expediently flat and perpendicular to a flat surface 25 on which the vehicle 1 stands. In the same step 13, a laser 21 is positioned at a predetermined laser position on one of the rear wheels 5. Using the laser 21, laser light 22 can now be emitted against the wall 19, such that the laser light 22 generates a vertical reference line 23 on the wall 19. Due to the position of the laser 21 on the respective rear wheel 5, the reference line 23 on the wall 19 represents a vehicle reference point, in particular a lateral vehicle boundary.The Laser 21 can, for example, be attached to the hub of a rim of the rear wheel 5. In the example of the . Fig. 1. A laser 21 is arranged on each of the two rear wheels 5, whereby only the adjustment of the left main headlight 10 is explained in detail here. The adjustment of the right main headlight 10 is then carried out in the corresponding manner. During the procedure 12, the headlight beam 20 can be projected against the wall 19 by means of the respective main headlight 10, the headlight beam 20 having a reference feature 24, which is represented here by a vertical line. In the example of the Fig. In the current state, the main headlight 10 is not optimally adjusted and therefore has an actual alignment with respect to the vehicle 1 that requires correction. As a result, the reference feature 24 on the wall has an actual position 26, which is also represented by the solid vertical line of the reference feature 24. With the main headlight 10 optimally aligned, this reference feature 24 on the wall 19 is in a target position 27, which is indicated by a dashed vertical line. In the example shown, Fig. 1. The actual position 26 is located to the right of the target position 27.

[0034] After positioning the vehicle 1 in front of the wall 19 and attaching the laser 21 to the rear wheel 5 according to step 13, step 14 involves measuring a longitudinal distance 28 between the wall 19 and a vehicle reference point 29. In this example, the vehicle reference point 29 is preferably located on the rear axle 4. The distance measurement is expediently performed on the side of the vehicle on which the main headlight 10 is to be adjusted. In this example, the Fig. 1. The left main headlight 10 is to be adjusted. Accordingly, the longitudinal distance 28 is conveniently measured at the left rear wheel 5. For illustrative purposes only, in Fig. 1 The longitudinal distance 28 is shown at the right rear wheel 5.

[0035] In step 15, an angular deviation 30 is calculated, which exists at wall 19 between the reference line 23 and the target position 27. The angular deviation 30 represents a measured or measurable horizontal target distance 31 at wall 19 between the reference line 24 and the target position 27. The angular deviation 30 is calculated from the measured longitudinal distance 28, taking into account the geometric positions of the main headlight 10, laser 21, and vehicle reference point 29. Trigonometric considerations first yield the target position 27 of the reference feature 24 on the wall 19 and the position of the reference line 23 on the wall 19, depending on the measured longitudinal distance 28 and the known geometric positions of the main headlight 10, laser 21, and vehicle reference point 29. From the target position 27 and the position of the reference line 23, the target distance 31 and the angular deviation 30, respectively, can then be calculated.The angular deviation 30 represents the angle by which the main beam direction 11 of the main headlight 10 must be rotated about a vertical axis so that, with the main headlight 10 in its intended alignment, the reference feature 24 on the wall 19 lies on the reference line 23.

[0036] After calculating the angular deviation 30 in step 15, a digital angle correction of the main beam direction 11 of the main headlight 10 is activated in step 16, specifically by the angle value of the calculated angular deviation 30. It is clear that for this purpose, the respective main headlight 10 is configured so that the main beam direction 11 can be digitally changed. With the main headlight 10 optimally aligned, the activation of the digital angle correction results in the reference feature 24 of the headlight beam 20 lying on the reference line 23 on the wall 19. If this is not the case after activation of the angle correction, the main headlight 10 is not optimally aligned with respect to the vehicle 1, but rather has an actual alignment that deviates from the target alignment and must therefore be corrected or adjusted. Fig. 1 is for the main headlight 10, which is not optimally aligned, i.e., in the case of an actual alignment deviating from the target alignment with a broken line, a corrected actual position 26' is indicated as a further vertical line on the wall 19, which the reference feature 24 assumes after activation of the digital angle correction on the wall 19. It is evident in Fig. 1 With angle correction activated, the reference feature 24 or the corrected actual position 26' is laterally spaced from the reference line 23, so that there is a horizontal and measurable transverse distance 32 between the reference line 23 and the corrected target position 26' or the reference feature 24, measured or measurable along the wall 19.

[0037] In step 17, the headlight 10 is adjusted by changing its alignment with the vehicle 1 until the lateral distance 32 is eliminated. In other words, the headlight 10 is adjusted, specifically rotated, with respect to its alignment with the vehicle 1 until the reference feature 24 lies on the reference line 23. The adjusted alignment then corresponds to the target alignment, so that the headlight 10 is optimally adjusted. The headlight 10 is adjusted mechanically and preferably manually by a person. The headlight 10 can be equipped with suitable adjusting screws or the like for this purpose.

[0038] In the final step 18, the digital angle correction of the main headlight 10 is deactivated again. Afterwards, the reference feature 24 on the wall 19 has the calculated target position 26 and the corresponding target distance 31 from the reference line 23.

[0039] The laser 21 can be conveniently positioned on the respective rear wheel 5 such that the laser light 22 is perpendicular to the rear axle 4. In this case, the laser light 22' extends parallel to the driving axis 8 along a dashed line, resulting in a different position for the reference line 23' on the wall 19. However, the respective rear wheel 5 can have a pivot axis 33 that is inclined at a track angle 34 relative to the rear axle 4. If the laser light 22 is perpendicular to the rear axle 4, the track angle 34 can be taken into account when calculating the angular deviation 30. Alternatively, it is also possible to position the laser 21 on the rear wheel 5 such that the laser light 22 is perpendicular to the pivot axis 33. The laser light 22 perpendicular to the pivot axis 33 then also has a track angle 34 relative to the laser light 22' perpendicular to the rear axle 4.In this procedure, the track angle 34 is automatically taken into account, so that the reference line 23 relating to the left rear wheel 5 is shifted slightly to the right according to the track angle 34.

[0040] If the motor vehicle 1 has a left main headlight 10 and a right main headlight 10, as shown here, the laser 21 for adjusting the left main headlight 10 is arranged on the left rear wheel 5, while the laser 21 for adjusting the right main headlight 10 is arranged on the right rear wheel 5.

[0041] A particularly advantageous configuration is one in which the respective main spotlight 10 is configured to operate in an adjustment mode, wherein, in adjustment mode, the spotlight light 20 emitted by the main spotlight 10 generates an adjustment image 35 on the wall 19, which is characterized by a particularly distinctive reference feature 24. In particular, the adjustment image 35 can be configured as a crosshair 36 or have a crosshair 36 as a reference feature 24.

[0042] In the example shown here, the position of the rear wheel 5 on the vehicle 1 is used as the vehicle reference point 29. In particular, the relative position of the rear axle 4, preferably an intersection of the rear axle 4 and the axis of rotation 33, can be used as the vehicle reference point 29. A laser 21 is particularly advantageous in this context, as it is additionally configured to allow distance measurement using the laser light 22. Thus, the longitudinal distance 28 between the laser position on the rear wheel 5 (as the vehicle reference point 29) and the wall 19 can be measured using the laser 21 located on the rear wheel 5.

[0043] The laser 21 can be configured to emit laser light 22' perpendicular to the rear axle 4 along the dashed line to measure the longitudinal distance 28, and to emit laser light 22 perpendicular to the axis of rotation 33 of the rear wheel 5 to generate the reference line 23. Alternatively, the laser 21 can be configured to emit laser light 22 perpendicular to the axis of rotation 33 for both measuring the longitudinal distance 28 and generating the reference line 23. The measured longitudinal distance 28 can be corrected by the track angle 34 of the rear wheel 5 in step 14 or 15. The corrected longitudinal distance 28 can then be used in step 15 to calculate the angular deviation 30.

[0044] In step 13, the motor vehicle 1 is positioned in front of the wall 19 such that a minimum distance 37 is maintained between the wall 19 and the respective vehicle reference point 29, which is at least as large as the distance 38 between the front axle 2 and the rear axle 4. In particular, this minimum distance 37 can be at least twice as large as the distance 38 between the front axle 2 and the rear axle 4.

Claims

[1] Method (12) for adjusting a main headlight (10) of a motor vehicle (1), - in which the motor vehicle (1) is positioned in front of a wall (19) such that a front axle (2) of the motor vehicle (1) is located between the wall (19) and a rear axle (4) of the motor vehicle (1), - in which a laser (21) is arranged in a predetermined laser position on a rear wheel (5) of the rear axle (4) and laser light (22, 22') is emitted by means of the laser (21) against the wall (19) in such a way that the laser light (22, 22') generates a reference line (23) on the wall (19), - in which, by means of the respective main headlight (10), headlight light (20) is emitted against the wall (19), which creates a reference feature (24) on the wall (19), - where a longitudinal distance (28) is measured between a vehicle reference point (29) and the wall (19), - in which, depending on the measured longitudinal distance (28) and taking into account the geometric positions of the main headlight (10), laser (21) and vehicle reference point (29), an angular deviation (30) between the reference line (23) and a target position (27) of the reference feature (24), which the reference feature (24) has on the wall (19) at the measured longitudinal distance (28) and at a target alignment of the main headlight (10), is calculated, - where a digital angle correction is activated at the main headlight (10) with the angle value of the calculated angle deviation (30), - in the event that the reference feature (24) on the wall (19) is not on the reference line (23), the alignment of the main headlight (10) is changed and adjusted so that the reference feature (24) on the wall (19) is on the reference line (23), - where the angle correction is deactivated. [2] Method (12) according to claim 1, characterized by , - that the laser (21) is positioned on the respective rear wheel (5) such that the laser light (22') is perpendicular to the rear axle (4). [3] Method (12) according to claim 2, characterized by , - that when calculating the angular deviation (30) a toe angle (34) of the rear wheel (5) is taken into account. [4] Method (12) according to claim 1, characterized by , - that the laser (21) is arranged on the respective rear wheel (5) such that the laser light (22) is perpendicular to a rotation axis (33) of the respective rear wheel (5). [5] Method (12) according to any one of the preceding claims, characterized by , - that the respective main spotlight (10) is configured to operate in an adjustment mode in which the emitted spotlight light (20) produces an adjustment image (35) on the wall (19) having the reference feature (24). [6] Method (12) according to claim 5, characterized by , - that the setting image (35) is configured as a crosshair (36) or has a crosshair (36) as a reference feature (24). [7] Method (12) according to any one of the preceding claims, characterized by , - that the laser position is used as the vehicle reference point (29), - that the laser (21) is configured for distance measurement using the laser light (22, 22'), - that the laser (21) arranged on the rear wheel (5) is used to measure the longitudinal distance (28) between the laser position and the wall (19). [8] Method (12) according to claim 7, characterized by , - that the laser (21) is configured to emit the laser light (22') perpendicular to the rear axle (4) to measure the longitudinal distance (28) and to emit the laser light (22) perpendicular to the axis of rotation (33) of the rear wheel (5) to generate the reference line (23). [9] Method (12) according to claim 7, characterized by , - that the laser (21) is configured to emit the laser light (22) perpendicular to the axis of rotation (33) of the rear wheel (5) for measuring the longitudinal distance (28) and generating the reference line (23), - that the measured longitudinal distance (28) is corrected by a toe angle (34) of the rear wheel (5), - that the corrected longitudinal distance (28) is used to calculate the angular deviation (30). [10] Method (12) according to any of the preceding claims, characterized by , - that the motor vehicle (1) is positioned in front of the wall (19) such that a minimum distance (37) is maintained between the wall (19) and the vehicle reference point (29) which is at least twice the distance (38) between the front axle (2) and the rear axle (4).

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