HEADLAMP FOR VEHICLES AND PROJECTION METHOD

Abstract

A headlamp for vehicles that has a light source unit. Numerous light sources and/or light guides are controllable individually. A sensor unit for detects headlamp status data and/or vehicle environment data. A control unit for controlling the light sources and/or light guides generates a predefined light distribution for the headlamp. The range of the headlamp can be adjusted on the basis of sensor signals from the sensor unit. The control unit contains a control element for the light sources and/or light guides for projecting a guide marking onto a road surface. The control unit contains a compensator that compensates for deviations in the guide marking on the basis of a sensor signal generated by the sensor unit.

Claims

1. A headlamp for vehicles, the headlamp comprising: a light source unit containing numerous light sources and/or light guides that can be controlled individually; a sensor unit for detecting headlamp status data and/or vehicle environment data; a control unit for controlling the light sources and/or light guides to generate a predefined light distribution for the headlamp, wherein a range of the headlamp is adjustable based on sensor signals from the sensor unit; wherein the control unit contains a control element for the light sources and/or light guides for projecting a guide marking on a road surface, and wherein the control unit contains a compensator that compensates for deviations in the guide marking on the basis of a sensor signal generated by the sensor unit.

2. The headlamp according to claim 1, wherein the compensator compensates for the deviations in a position of the guide marking based on an operating state of the vehicle and/or an inclination of the light source unit.

3. The headlamp according to claim 2, wherein the compensator adjusts the range of the headlamp on the basis of the operating state of the vehicle and/or to compensate for an inclination of the headlamp in relation to a reference position thereof.

4. The headlamp according to claim 3, wherein the control unit is configured such that the range of the headlamp in the reference position thereof is dependent on a predefined light distribution for an operating state of the vehicle.

5. The headlamp according to claim 1, wherein the light sources and/or light guides in the light source unit are attached to a mount that remains stationary in the housing for the headlamp.

6. The headlamp according to claim 1, wherein the guide marking forms two lane markings that are parallel to lane markings.

7. The headlamp according to claim 1, wherein the compensator contains a compensation dataset in which different pitch angles (?) are assigned different compensation values, such that the light source unit is controlled with different compensation signals for the compensation values for different pitch angles (?).

8. The headlamp according to claim 7, wherein the pitch angles (?) are listed in 1? increments.

9. The headlamp according to claim 1, wherein intermediate values between individual pitch angles (?) are calculated through interpolation.

10. The headlamp according to claim 1, wherein the light source unit and the control unit are contained in the same housing for the headlamp.

11. The headlamp according to claim 1, wherein the control unit for controlling the range of the light sources or light source unit and/or the position of the guide marking is outside the housing for the headlamp.

12. A method for projecting a guide marking onto a road surface for vehicles, the method comprising: controlling numerous light sources and/or light guides in a light source unit, such that the guide marking for a predefined path, which is based on a vehicle operating parameter, is continuously projected onto the road surface while the vehicle is traveling, setting the path of the guide marking on the basis of the operating parameter in the form of an inclination angle (?) detected for the vehicle.

13. The method according to claim 12, wherein the light sources and/or light guides are controlled with a control signal with which the guide marking and the range of the headlamp are set.

14. The method according to claim 12, wherein the range of the headlamp and the guide marking are set based on the operating parameter for the vehicle in the form of the detected inclination angle.

15. The method according to claim 12, wherein the light sources and/or light guides for generating guide markings on the road surface are controlled using a control table containing values for the inclination angle (?).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Reference is now made more particularly to the drawings, which illustrate the best presently known mode of carrying out the invention and wherein similar reference characters indicate the same parts throughout the views.

[0024] FIG. 1 shows a block diagram of a first embodiment of the device according to the invention.

[0025] FIG. 2 shows guide markings when the vehicle is traveling in a straight line, with the headlamp in a reference position.

[0026] FIG. 3 shows the guide markings when the vehicle accelerates.

[0027] FIG. 4 shows the guide markings when the vehicle decelerates.

[0028] FIG. 5 shows a control table with pitch angle values assigned to compensation values.

[0029] FIG. 6 shows a block diagram for an alternative embodiment of the device according to the invention.

DETAILED DESCRIPTION OF THE DRAWINGS

[0030] A headlamp for a vehicle has a housing 1 containing a light source unit 2 and a control unit 3 for the light source unit. There is a sensor unit 4 outside the housing.

[0031] In this exemplary embodiment, the light source unit 2 contains numerous light sources 5 that are arranged in a matrix, e.g. on a chip, and can be controlled individually. The light sources 5 can have a dedicated optical element, e.g. a lens and/or reflector, with which the individual light sources 5 are focused into pixels forming a predefined light distribution 7, e.g. a low beam light distribution, projected onto a road surface 6 in front of the vehicle. This is a high resolution headlamp, the matrix of which contains 256 rows and 64 columns, thus obtaining over 16,000 pixels.

[0032] According to an alternative embodiment of the invention, the light source unit 2 can also contain light guides, e.g. a digital micromirror device (DMD), a liquid-crystal display (LCD), or liquid crystal on silicon (LCoS), with which the desired light distribution, or an additional guide marking 8, is generated.

[0033] The guide marking 8 in the present exemplary embodiment is composed of two tracking lines 9, 9, which converge in front of the vehicle when it its traveling in a straight path, corresponding to the perspective impression of the lane lines 10, 11 on the road surface. The tracking lines 9, 9 are straight lines, like the solid lane line 10 on the edge of the road surface and the broken lane line 11 in the middle of the road.

[0034] The straight tracking lines 9, 9 are as far apart in front of the vehicle as the width thereof, or the distance between the front wheels. This image of the guide marking 8 shows the driver the intended path for the vehicle. At a constant speed, the tracking lines 9, 9 of the guide marking 8 indicate the path shown in FIG. 2, in which the headlamp, or the light source unit 2 is in a reference position. The tracking lines 9, 9 converge at an angle ?.

[0035] When the vehicle accelerates, the tracking lines 9, 9 converge at an angle ?, which is smaller than the angle ? when the headlamp is in the reference position (at a constant speed of the vehicle), as shown in FIG. 3.

[0036] When the vehicle decelerates, the tracking lines 9, 9 converge at an angle ?, which is greater than the angle ? when the headlamp is in the reference position, as shown in FIG. 4. Consequently, the guide marking 8 changes in relation to the vehicle during acceleration or deceleration, which is disruptive for the driver. To prevent this, the control unit 3 has a compensator 12. The compensator 12 contains a range compensator 13 that adjusts the headlamp range, and a guide marking compensator 14 that adjusts the guide marking 8 in the event of a disruption. The disruption is detected by the sensor unit 4, which contains numerous sensors 4, 4, 4. A first sensor 4 can be an axle sensor, or inclination sensor. A second sensor 4 can be an acceleration sensor. A third sensor 4 can be a camera.

[0037] The sensor unit 4 generates a sensor signal 15 that is sent to the control unit 3. The control unit 3 contains a control element 16 that processes and evaluates the sensor data (sensor signal 15), and sends a control signal 17 to the light source unit 2. When the sensor signal 15 indicates a disruption, e.g. acceleration or deceleration of the vehicle, the control signal 17 is generated on the basis of a compensation signal 18, which is determined by the compensator 12. In addition, an adjustment of the headlamp range is calculated by the range compensator 13. An adjustment of the guide marking 8 is determined during the disruption by the guide marking compensator 14. The compensation signal 18 acts on the control element 16 such that when the vehicle accelerates or decelerates, the position of the guide marking 8 is altered such that it corresponds to that at a constant speed. The compensation signal 18 also adjusts the headlamp range during acceleration or deceleration, such that other road users are not blinded, and such that it corresponds to that at a constant speed.

[0038] It is assumed that at a constant speed, the headlamp is in a reference position. Inclination of the vehicle is only indicated by the sensor signal 15 when the roadway is uneven, or during acceleration or deceleration, resulting in a disrupted position of the vehicle or headlamp.

[0039] The headlamp range adjustment applies to numerous light distributions, e.g. the low beam light distribution, highway light distribution, urban light distribution, etc.

[0040] The guide marking compensator 14 contains a compensation data set (control table), preferably in the form of a table, containing numerous compensation values K1, K2, K3, K4, K5, and K1, K2, K3, K4, K5 that are assigned to different pitch angles (inclination angles) ?. The pitch angle ? is detected by the inclination sensor 4. When the headlamp is in the reference position, i.e. at a constant speed on a flat road 6, the pitch angle ? is zero. The headlamp is in a default setting, or reference position. When the pitch angle ? is between ?5? and +5?, corresponding compensation values K1, K2, K3, K4, K5, or K1, K2, K3, K4, K5 are calculated and stored in 1? increments.

[0041] If a pitch angle ? of +1? is detected, the compensation signal K1 is obtained from the compensation dataset, and if the pitch angle ? increases to +2?, the compensation signal K2 is obtained from the compensation data set.

[0042] To prevent undesired jumps in the guide marking 8, intermediate values for the compensation signals 18 are calculated through interpolation between adjacent pitch angles, such that when the disrupted position of the headlamp changes, the driver does not notice any change in the position of the guide marking.

[0043] The control element 16 evaluates the compensation signals 18 from the range compensator 13 and the guide marking compensator 14 such that the headlamp range and the guide marking 8 are adjusted simultaneously.

[0044] According to an alternative embodiment of the invention, not shown herein, the control unit 3 can also be outside the headlamp housing.

[0045] According to another embodiment of the invention, shown in FIG. 6, the control unit 3 contains a headlamp range control unit 19 and a guide marking control unit 20. The guide marking control unit 20 is a supplementary control unit, which can be inside or outside the headlamp housing. The guide marking control unit 20 contains a guide marking compensator 21 and a control element 22. The control signal 23 generated by the guide marking control unit 20 is used to adjust the current guide marking 8 when the position of the headlamp is disrupted.

[0046] The headlamp range control unit 19 contains a range compensator 24 and a control element 25. The control signal 26 generated by the range compensator 19 acts on the light source unit 2 such that the range is adjusted when the position of the headlamp is disrupted. In this embodiment, the headlamp range and guide marking 8 are adjusted independently of one another.

[0047] According to the embodiment of the invention shown in FIG. 1, the control signal 17 is generated by the control unit 3, which acts on the light source unit 2 such that the headlamp range and the guide marking 8 are adjusted when the position of the headlamp is disrupted, in which case the guide marking 8 is altered such that it assumes the same position when the vehicle is tilted that it would be in if the vehicle were not tilted, i.e. the headlamp were in the reference position. Even when the position of the headlamp is disrupted, in particular when the vehicle tilts, the headlamp range and guide marking 8 remain the same.

[0048] The adjustment of the headlamp range and guide marking 8 therefore takes place on the basis of operating parameters for the vehicle determined by the sensor unit 4.

[0049] The guide marking 8 is always adjusted to the current pitch angle, in particular by the calculated and interpolated compensation values K1, K2, K3, K4, K5, or K1, K2, K3, K4, K5 with the invention while the vehicle is in operation.

[0050] According to an alternative embodiment of the invention, not shown herein, the guide marking can be straight or curved line, and/or surface area, and/or symbol.

LIST OF REFERENCE SYMBOLS

[0051] 1 housing [0052] 2 light source unit, [0053] 3, 3 control unit [0054] 4-4 sensor unit [0055] 5 light source [0056] 6 road surface [0057] 7 light distribution [0058] 8 guide marking [0059] 9, 9 tracking lines [0060] 10 lane line [0061] 11 middle line [0062] 12 compensator [0063] 13 headlamp range compensator [0064] 14 guide marking compensator [0065] 15 sensor signal [0066] 16 control element [0067] 17 control signal [0068] 18 compensation signal [0069] 19 headlamp range control unit [0070] 20 guide marking control unit [0071] 21 guide marking compensator [0072] 22 control element [0073] 23 control signal [0074] 24 headlamp range compensator [0075] 25 control element [0076] 26 control signal [0077] a spacing [0078] ? pitch angle/inclination angle [0079] K1-K5 compensation values [0080] K1-K5 compensation values