Method for calibrating a vehicle interior lighting system, and motor vehicle
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- BAYERISCHE MOTOREN WERKE AG
- Filing Date
- 2026-01-09
- Publication Date
- 2026-08-06
Smart Images
Figure DE2026100015_06082026_PF_FP_ABST
Abstract
Description
[0001] 24-2581
[0002] 1
[0003] METHOD FOR CALIBRINGING A VEHICLE INTERIOR LIGHTING AND MOTOR VEHICLE
[0004] The invention relates to a method for calibrating a vehicle interior lighting system, comprising a control unit, a data storage device, at least one light source designed to emit colored light, and a light output surface through which light emitted by the at least one light source is directed towards a vehicle interior, wherein the light output surface is provided with a translucent surface material. The invention further relates to a motor vehicle with corresponding interior lighting.
[0005] Interior lighting plays an increasingly important role in creating a high-quality appearance in a vehicle interior. It shapes the overall look of the interior, especially at dusk or at night. The ability to configure various interior finishes, such as different fabrics, leathers, and hard materials like wood or plastic, combined with different colors, results in a wide variety of interior lighting options. So-called contour line lighting highlights individual interior elements. In the future, it will be possible to illuminate different surface materials, such as synthetic leather, fabrics, knits, and the like, either as an alternative or in addition to contour line lighting.
[0006] When a colored upper material is illuminated by the vehicle's interior lighting, it appears a different color if it is intended to be white, whereas the contour line lighting, which is not translucent due to the upper material, would appear white. The interior lighting and the contour line lighting thus appear different colors within the vehicle interior, negatively impacting the overall visual impression.
[0007] The object of the invention is to provide a method by which, regardless of the type and / or color of a surface material arranged on a vehicle interior light, light emission with a light color corresponding to a light color that would be emitted by the vehicle interior light without the surface material can be achieved. 24-2581
[0008] 2
[0009] Another object of the invention is to provide a motor vehicle comprising interior lighting that enables a uniform appearance, regardless of whether a top material is applied to it or not.
[0010] This problem is solved by the features of the method according to claim 1 and a motor vehicle according to the features of claim 11. Advantageous embodiments result from the dependent claims.
[0011] A method for calibrating interior lighting is proposed, comprising a control unit, a data storage device, at least one light source designed to emit colored light, and a light output surface through which light emitted by the at least one light source is directed towards a vehicle interior. The light output surface is provided with a translucent surface material. This translucent surface material can be, for example, colored synthetic leather, a fabric, a knitted fabric, a plastic, or the like.
[0012] The process includes the following steps:
[0013] In step a), the at least one light source is controlled with a set of control parameters, which includes an individual reference color parameter for each color channel in a given color space, wherein the set of control parameters causes the at least one light source to emit a reference light through the upper material towards the vehicle interior.
[0014] The specified color space is, in particular, an RGB color space comprising red, green, and blue as color channels. As is known to those skilled in the art, the colors of the individual color channels are defined in an 8-bit architecture with values between 0 and 255. Alternatively, the specified color space can be an XYZ color space according to CI E-Tristimulus, comprising chromatic coordinates in an xy coordinate system as color channels. The invention can be used with any color space. In particular, it is also possible to convert colors of one color space into colors of another color space when carrying out the method. The conversion methods required for this are known to those skilled in the art.
[0015] In particular, a white light with a predetermined light color is used as a reference light, which is defined by the respective reference color parameter values in the color space used.24-2581
[0016] 3
[0017] is defined. For example, a light with a color temperature can be used to which at least one light source of the vehicle's interior lighting has been calibrated by the vehicle's interior lighting manufacturer. In an RGB color space, the color parameter values 255 / 255 / 255 or 250 / 250 / 250 can be used as reference color parameters for the R / G / B channels. Of course, other color parameter values for the color channels are also possible.
[0018] In step b), the color of the light emitted from the vehicle's interior lighting is detected in the area of the upper material using a color sensor. A camera or a spectral sensor can be used as the color sensor. The camera or spectral sensor can be part of a handheld or robot-guided sensor unit used during the vehicle's manufacturing process. Such a sensor unit includes, in addition to the color sensor, a microcontroller for acquiring and, optionally, (pre-)processing the measured values provided by the color sensor, a power supply, and, if necessary, a user interface (display) for visualizing processed measured values and / or other information. Alternatively, a vehicle-integrated camera, such as one mounted on the rearview mirror to capture the vehicle's interior, can be used as the color sensor.The processing of the measured values provided by the vehicle's own camera can be carried out by the processing unit of the vehicle's interior lighting or another processing unit of the vehicle.
[0019] In step c), a set of color parameters for the detected light color is determined, wherein the set of color parameters comprises an individual measurement color parameter for each color channel in the specified color space. The individual measurement color parameters, which are preferably determined or converted within the specified color space, deviate from the reference color parameters used to control the at least one light source due to the illuminated surface material, in particular its properties and / or color. The individual measurement color parameters represent this deviation for each color channel.
[0020] In step d), a set of correction parameters is determined, wherein the set of correction parameters includes an individual correction parameter for each color channel by processing the measurement color parameter and the reference color parameter in a predefined manner for each color channel. The individual correction parameters typically differ for each color channel of the specified color space. Depending on the translucent upper material, the 24-2581
[0021] 4
[0022] The individual correction parameters of the color channels must match. Channel-by-channel processing of the measurement color parameters and the reference color parameters can be performed using a calculation formula that relates the reference color parameter and the measurement color parameter, and / or terms with these color parameters, to each color channel. The individual correction parameters can be stored in the data memory for further processing when using the vehicle's interior lighting.
[0023] In step e), a set of selection control parameters is received, comprising an individual selection color parameter for each color channel in the specified color space. This set of selection control parameters causes at least one light source to emit light of a specified color. The individual selection color parameters can match the reference color parameters. However, other individual selection color parameters can also be chosen, for example, to produce colored light. The individual selection color parameters serve to verify the accuracy of the color calibration.
[0024] In step f), a set of corrected selection control parameters is determined. This set comprises one individual corrected selection control parameter for each color channel in the specified color space. The determination is carried out by correcting the received individual selection color parameters channel by channel with their respective individual correction parameters. This ensures that when the at least one light source is activated with the set of corrected selection control parameters, the at least one light source is caused to emit light through the surface material towards the vehicle interior, the color parameters of which, upon measurement, correspond to the selection color parameters.
[0025] During vehicle operation, either the corrected selection control parameters or the set of correction parameters, which includes an individual correction parameter for each color channel, can be stored in the vehicle's interior lighting data storage. This ensures that, for any chosen set of selection control parameters, e.g., to generate blue, red, yellow, or white light, the corresponding individual correction parameters are used in such a way that the respective corrected selection control parameters are determined by the control unit and used to control at least one light source.
[0026] In other words, additive color mixing produces a desired target color, which is defined by the selection color parameters. 24-2581
[0027] 5
[0028] This approach is based on the consideration that not all surface materials produce the desired lighting result, but rather influence the lighting experience perceived by the user. For example, if a red synthetic leather is used as the surface material, which must be illuminated by the vehicle's interior lighting, then if the intended white color is white (which also appears white in other lighting elements that are not covered with a translucent surface material), the red synthetic leather will make it appear pink. The components will therefore no longer be the same color as other lighting elements in the vehicle interior.However, calibrating the desired color with the help of the color sensor enables the desired target image, so that vehicle interior lighting systems that are equipped with a translucent surface material on the one hand and do not have a translucent surface material on the other hand have an almost identical appearance with regard to the light color when illuminated.
[0029] It is advantageous to determine the individual correction parameters for each color channel only once during the manufacturing of the vehicle's interior lighting. As described, either a handheld camera or a spectral sensor can be used as the color sensor for this purpose. The corresponding technical components can, for example, be used as a sensor unit during manufacturing to detect the color of the light emitted from the vehicle's interior lighting in the area of the surface material using the color sensor.
[0030] Alternatively, the determination of individual correction parameters for each color channel can be performed once or at predetermined intervals during vehicle operation. For this purpose, a camera located in the vehicle interior can be used as a color sensor to detect the color of the light emitted from the vehicle's interior lighting in the area of the upper material. The resulting individual measurement color parameters are then used together with the reference color parameters to determine the individual correction parameter for each color channel relative to the vehicle's interior lighting. In particular, the determination of individual correction parameters for each color channel is performed when the vehicle is not in use.
[0031] This ensures that the vehicle user does not notice the calibration of the vehicle's interior lighting.
[0032] As already explained, the individual correction parameters are stored in the data memory of the vehicle's interior lighting system in order to be available after receiving a set on24-2581
[0033] 6
[0034] Selection control parameters are processed to determine the corrected selection control parameters.
[0035] It is advantageous to persistently store the individual correction parameters for each color channel in the data memory of the vehicle's interior lighting.
[0036] The individual correction parameters are determined for each color channel depending on the type, color and texture of the upper material.
[0037] A motor vehicle according to the invention comprises an interior lighting system, which includes a control unit, a data storage device, at least one light source designed to emit colored light, and a light output surface through which light emitted by the at least one light source is directed towards the interior of the vehicle. It further comprises a translucent surface material arranged on the light output surface of the interior lighting system.The control unit is designed to, in response to a user request to control at least one light source with a specific light color, which is characterized by a set of selection control parameters that includes an individual selection color parameter for each color channel in the specified color space, to read predefined individual correction parameters for the surface material from the data memory and to calculate the individual selection color parameters channel by channel with the respective assigned individual correction parameters to corrected individual selection color parameters, and to process the corrected individual selection color parameters to control at least one light source.
[0038] The invention is described in more detail below with reference to an exemplary embodiment shown in the drawing. The drawing shows:
[0039] Fig. 1 shows a schematic representation of a vehicle interior lighting system, on whose light output surface a translucent upper material is arranged, as well as the components required for calibrating the vehicle interior lighting system; and
[0040] Fig. 2 shows a flowchart illustrating the essential steps of the inventive method for calibrating vehicle interior lighting. 24-2581
[0041] 7
[0042] Fig. 1 shows a schematic representation of a vehicle interior light 10, on whose light-emitting surface 17 a translucent upper material 20 is arranged. Furthermore, Fig. 1 shows the components required for calibrating the vehicle interior light 10.
[0043] The vehicle interior lighting 10 comprises a lighting unit 12 with at least one light source 13 to 16 designed to emit colored light. In the present embodiment, the lighting unit 12 comprises four light sources 13 to 16. The light sources 13 to 16 are, for example, RGB light-emitting diodes (RGB LEDs), i.e.
[0044] Light-emitting diodes (LEDs) in which red, green, and blue LEDs are combined in a single LED package in such a way that their light mixes well and thus appears white from the outside when the individual LEDs are appropriately controlled. For illustrative purposes only, the light sources 13 to 16 emit their light towards a flat light-emitting surface 17. The light-emitting surface 17 could, for example, be the outer surface of a light guide 19, e.g., made of a transparent plastic material. It is understood that the number and arrangement of the light sources 13 to 16 could be configured in any way. For example, light could also be coupled into the light guide 19 from the side.
[0045] The vehicle interior lighting 10 further comprises a control unit 11, which is configured to control the light sources 13 to 16 each with a set of control parameters. The set of control parameters includes an individual color parameter for each color channel in a predefined color space. If the familiar RGB color space is used as the predefined color space, the color channels comprise red, green, and blue. Alternatively, an XYZ color space according to CIE tristimulus could be used as the predefined color space. In this case, chromatic coordinates in an xy coordinate system are used as the color channels.
[0046] The following description merely assumes, by way of example, that the specified color space is the RGB color space. However, it is known to those skilled in the art that the colors or color channels of one color space can be converted into the colors or color channels of another color space.
[0047] Furthermore, the vehicle interior lighting 10 includes a data storage device 18, which, in the schematic representation of Fig. 1, is coupled to the control unit 11. The data storage device 18 could also be integrated into the control unit 11. 24-2581
[0048] 8
[0049] A translucent surface material 20 is arranged on the light output surface 17 of the lighting unit 12 of the vehicle interior lighting 10. The surface material 20 can be, for example, artificial leather, a fabric, a knitted or crocheted material, a plastic, or the like. The surface material 20 is, in particular, constructed like a film and can be fully illuminated, so that a homogeneous appearance is ensured on its surface facing the vehicle interior 21.
[0050] Applying the surface material 20, which has a color and material properties determined by the designers or the vehicle user, changes the color of the light emitted by the lighting unit 12. For example, the light passing through the surface material 20 alters the white point of the light. Depending on the material of the surface material 20, the difference in the shift of the light color is very noticeable. This is particularly evident when, in addition to the vehicle's interior lighting 10, where the surface material 20 is arranged on the light-emitting surface 17 of the lighting unit 12, other interior lighting systems are also provided whose light-emitting surfaces do not have color-distorting surface materials.
[0051] For this reason, calibration of the vehicle interior lighting 10 is provided. To perform this calibration, a color sensor 30 and a processing unit 31 are required, as shown in Fig. 1. The color sensor 30 is designed to detect the color of the light emitted by the vehicle interior lighting 10 in the area of the surface material 20. A camera or a spectral line sensor can be used as the color sensor 30. If a camera is used, it can be an internal vehicle camera that, for example, captures the vehicle interior 21 and thereby, at least partially, captures the vehicle interior lighting 10 with the surface material 20 applied to it. Alternatively, the camera can also be an external vehicle camera, which, for example, is used as a handheld or robot-guided sensor instrument during the manufacture of the vehicle for calibrating the vehicle interior lighting.The same applies when using a spectral sensor.
[0052] The detection of the light color of the light extracted from the vehicle interior lighting 10 in the area of the upper material using the color sensor 10 takes place in step S2, after the light sources 13 to 16 of the vehicle interior lighting are controlled with a set of control parameters, whose individual reference color parameters cause at least one light source 13 to 16 to emit a reference light through the upper material 24-2581
[0053] 9
[0054] 20 towards the vehicle interior 21 (step S1). Preferably, a light used for the factory calibration of the light sources 13 to 16 of the lighting unit 12 is used as a reference light. In the RGB color space, for example, a light with the values 255 / 255 / 255, i.e., white light, can be used as a reference light for the R / G / B channels. After calibration, the goal is that when the light sources are controlled with selected values R / G / B = a / b / c, the light emitted via the surface material 20 has values similar to the aforementioned values of a / b / c for each color channel.
[0055] In step S3, the processing unit 31 is used to determine a set of color parameters for the detected light color, whereby the set of color parameters includes an individual measurement color parameter for each color channel in the specified color space. Due to the illumination of the upper material 20, a color shift occurs depending on the type and properties of the upper material 20 as well as its color.
[0056] For example, measured values for the color channels R / G / B = 255 / 111 / 126 are obtained. It is obvious that this does not achieve the intended color tone (R / G / B = 255 / 255 / 255) in the area of the upper material 20.
[0057] In step S4, the processing unit 31 therefore determines a set of correction parameters, which includes an individual correction parameter for each color channel. Channel by channel, the measurement color parameter (R / G / B = 255 / 111 / 126) and the reference color parameter (R / G / B = 255 / 255 / 255) are processed in a predefined manner for each R / G / B color channel. A correction can, for example, be performed according to the following equations:
[0058] (1)
[0059] (2)
[0060] (3)
[0061]
[0062] where Rmes, Gmes and Bmes are the individual measurement color parameters and R cor Gcor, Bcor are the individual correction parameters of the respective color channels. R, G, and B represent the intended target parameters in equations (1) to (3), which in this case correspond to the reference color parameters. 24-2581
[0063] 10
[0064] In step S5, a set of selection control parameters is received. This set of parameters causes at least one light source 13-16 to emit light of a specified color. During calibration, the selection control parameters can correspond to the reference parameters. Generally, the selection control parameters represent the (control) parameters for each color channel R / G / B in the specified color space that define the light color to be generated by the lighting unit 12 and perceived in the vehicle interior 21. Typically, the selection control parameters are read from the data memory 18 as a result of user input, such as a color selection (red, blue, green, white, violet, etc.).
[0065] In step S6, a set of corrected selection control parameters is determined. This set comprises one individual corrected selection control parameter for each color channel in the specified color space. The individual corrected selection color parameters are determined by correcting each channel individually with its corresponding individual correction parameter. This ensures that when at least one light source is activated using this set of corrected selection control parameters, the light source (13-16) is caused to emit light through the surface material towards the vehicle interior, the color parameters of which correspond to the selection color parameters when measured.
[0066] The determination of the set of corrected selection control parameters is preferably carried out by the processing unit 31 or the processing unit of a control unit not shown here. The result of the calculation by the processing unit 31 can then be stored in the data memory 18 of the vehicle's interior lighting system. Alternatively, only the individual correction parameters for each color channel can be stored in the data memory 18, so that steps S5 and S6 would then each be executed by the control unit 11 after receiving a set of selection control parameters (i.e., a color to be displayed).
[0067] The set of corrected selection control parameters can be determined, for example, according to the following equations:
[0068]
[0069] 24-2581
[0070] 11
[0071] &
[0072] &
[0073]
[0074] where Rcor.ad, Gcor.ad, B CO r,ad are the individual corrected selection control parameters, normalized to the selected color space. In equations (4) to (6), the operator "Max" represents a maximum operator.
[0075] The determination of the individual corrected selection control parameters can be carried out, for example, using a spreadsheet program. Row 1 shows the individual measurement color parameters for the color channels R, G, and B for the following three examples (Example 1: beige upper material, Example 2: red upper material (Castanea), Example 3: gray upper material). Row 2 shows the individual selection color parameters, which are set, for example, by a customer (here, the customer requests white light (R / G / B = 251 / 251 / 251)). Row 4 shows the individually determined correction parameters, which are calculated channel by channel by applying formulas 1 to 3. Finally, row 6 shows the individually corrected selection control parameters determined using formulas 4 to 6, which are used to control at least one light source 13-16. Rows 3 and 5 show correction factors applied only for the calculation.
[0076] Example 1: beige upper material
[0077]
[0078] Example 2: red upper material (Castanea)
[0079]
[0080] 24-2581
[0081] 12
[0082]
[0083] Example 3: grey upper material
[0084]
[0085] The correction factors or correction parameters differ depending on the type, quality and color of the upper material.
[0086] In principle, it is sufficient to perform the individual correction parameters for each color channel R / G / B once during the production of the vehicle interior lighting 10, onto which the surface material 20 is applied. If a vehicle-integrated camera is used as the color sensor 30, the determination of the individual correction parameters for each color channel R / G / B can optionally be carried out once or at predetermined intervals during the operation of the vehicle, the latter being particularly relevant when the vehicle is not in use. This allows, for example, any degradation of the properties of the light sources 13 to 16 over time to be taken into account and compensated for.
[0087] The individual correction parameters for each color channel are stored persistently in the data memory 18 of the vehicle interior lighting 10.24-2581.
[0088] 13 Reference marks
[0089] 10 Vehicle interior lighting
[0090] 11 Control unit
[0091] 12 lighting units
[0092] 13 to 16 light sources
[0093] 17 Light output area
[0094] 18 Data storage devices
[0095] 19 optical fibers
[0096] 20 Upper material
[0097] 21 Vehicle interior
[0098] 30 color sensors
[0099] 31 computing unit
Claims
24-2581 14 Claims 1. Method for calibrating a vehicle interior lighting system (10) comprising a control unit (11), a data storage device (18), at least one light source (13-16) designed to emit colored light, and a light output surface (17) through which light emitted by the at least one light source (13-16) is emitted in the direction of a vehicle interior (21), wherein the light output surface (17) is provided with a translucent upper material (20), comprising the steps: a) Controlling the at least one light source (13-16) with a set of control parameters which includes an individual reference color parameter for each color channel in a specified color space, wherein the set of control parameters causes the at least one light source (13-16) to emit a reference light through the upper material (20) towards the vehicle interior; b Detecting the color of the light emitted from the vehicle interior lighting (10) in the area of the upper material (20) using a color sensor (30); c) Determining a set of color parameters for the detected light color, wherein the set of color parameters includes an individual measurement color parameter for each color channel in the specified color space; d) Determining a set of correction parameters that includes an individual correction parameter for each color channel by processing the measurement color parameter and the reference color parameter in a predefined manner for each color channel; e) Receiving a set of selection control parameters comprising an individual selection color parameter for each color channel in the specified color space, wherein the set of selection control parameters causes the at least one light source (13-16) to emit light of a specified color; f) Determining a set of corrected selection control parameters by correcting the received individual selection color parameters channel-wise with the respective assigned individual correction parameter such that, when the at least one light source (13-16) is driven with the set of corrected selection control parameters, the at least one light source (13-16) is caused to emit light through the upper material (20) towards the vehicle interior (21), the color parameters of which, upon measurement, correspond to the selection color parameters. 24-2581 15 2. The method of claim 1, wherein the specified color space is an RGB color space comprising red, green and blue as color channels.
3. Method according to claim 1 or 2, wherein the specified color space is an XYZ color space according to CI E-Tristimulus, comprising as color channels chromatic coordinates in an xy coordinate system.
4. Method according to one of claims 1 to 3, wherein the determination of the individual correction parameters for each color channel is carried out once during the manufacture of the vehicle interior lighting (10).
5. Method according to one of claims 1 to 3, wherein the determination of the individual correction parameters for each color channel is carried out once or at predetermined intervals during the operation of the vehicle.
6. Method according to claim 5, wherein the determination of the individual correction parameters for each color channel is carried out particularly during a period of non-use of the vehicle.
7. Method according to one of the preceding claims, wherein the individual correction parameters for each color channel are persistently stored in the data storage device (18) of the vehicle interior lighting (10).
8. Method according to any of the preceding claims, wherein the individual correction parameters for each color channel depend on the type, color and quality of the upper material (20).
9. Method according to one of claims 1 to 3, wherein the detection of the light coupled out from the vehicle interior lighting (10) is carried out by a camera, in particular a vehicle-specific camera.
10. Method according to one of claims 1 to 9, wherein the detection of the light coupled out from the vehicle interior lighting (10) is carried out by a spectral sensor.
11. Motor vehicle including: 24-2581 16 a vehicle interior lighting system (10) comprising a control unit (11), a data storage device (18), at least one light source (13-16) designed to emit colored light, and a light output surface (17) through which light emitted by the at least one light source (13-16) is emitted in the direction of a vehicle interior, - a translucent upper material (20) arranged on the light output surface (17) of the vehicle interior lighting system (10); wherein the control unit (11) is configured to read out predefined individual correction parameters for the upper material (20) from the data storage (18) in response to a user request to control the at least one light source (13-16) with a specific light color, which is characterized by a set of selection control parameters that includes an individual selection color parameter for each color channel in the specified color space, and to calculate the individual selection color parameters channel by channel with the respective assigned individual correction parameters to corrected individual selection color parameters, and to process the corrected individual selection color parameters to control the at least one light source (13-16).