Method for operating a lighting device in a motor vehicle

Abstract

A method for operating a lighting device in a motor vehicle, wherein the lighting device comprises a plurality of lighting units (LE1, LE2, ..., LE26) that are connected to a communication bus (2) in the motor vehicle and receive messages (ME) sequentially from a control unit (1) via the communication bus (2), wherein the lighting units (LE1, LE2, ..., LE26) of the plurality of lighting units (LE1, LE2, ..., LE26) are divided into several groups (G1, G2, G3, G4) each consisting of one or more lighting units (LE1, LE2, ..., LE26), and each message (ME) is assigned a group (G1, G2, G3, G4), wherein each message (ME) specifies one or more operating parameters (FB, HE, TFB, THE) for an individual lighting unit (LE1, LE2, ..., LE26) and a respective lighting unit (LE1, LE2, ..., LE26) which is in the assigned group (G1, G2, G3, G4) of a received message (ME), carries out its operation based on the operating parameter(s) (FB, HE, TFB, THE) from the received message (ME), characterized in that the control unit (1) changes the division of the plurality of lighting units (LE1, LE2, ..., LE26) into groups (G1, G2, G3, G4) at least once during the operation of the lighting device.

Description

[0001] The invention relates to a method for operating a lighting device in a motor vehicle and to a corresponding lighting device.

[0002] Lighting devices for motor vehicles are known from the prior art. These devices comprise a plurality of lighting units connected to a communication bus, such as a LIN bus (LIN = Local Interconnect Network). A control unit of the lighting device sends messages to the LIN bus that change the operating parameters of the lighting units. Such lighting devices are often installed in the interior of a motor vehicle to create different lighting effects using the lighting units.

[0003] In lighting devices of the above type, messages are sent to the communication bus at a predetermined rate. A single message can only specify the operating parameters of a single lighting unit. Consequently, a single message has traditionally only been used to change the operating parameters of a single lighting unit specified in the message. However, this poses the problem that a desired simultaneous change to the operating parameters of multiple lighting units is associated with a time delay, since the control unit sends corresponding messages to the communication bus one after the other. Consequently, the user may perceive an undesirable time delay when switching between lighting units.

[0004] To solve the above problem, it is known from the prior art to define predefined groups of lighting units in the control unit of the lighting device, whereby each message sent on the communication bus is assigned to a group and contains identical operating parameters for each lighting unit in the group. This way, time delays when switching lighting units can be avoided. However, by defining the predefined groups, it is always predetermined which lighting units change their appearance or behavior simultaneously. This limits the possibilities for creating dynamic lighting effects.

[0005] Document DE 11 2014 003 826 T5 discloses a device for providing lighting for a vehicle interior, in which the properties of the lighting are adapted to the properties of the vehicle's exterior environment. The device comprises an LED strip divided into sections, with the color data for one section of the LED strip being transmitted separately from those for other sections of the LED strip.

[0006] Document DE 10 2006 021 694 B4 shows a lighting device for a motor vehicle comprising several separate modules consisting of multiple LEDs. The modules can be controlled completely, so that all LEDs are operated evenly. The LEDs can also be divided into groups and controlled individually.

[0007] Document DE 10 2016 207 724 A1 discloses a method for controlling a lighting device of a vehicle, in which light sources are controlled via a virtual coordinate system. Each of the light sources is assigned a coordinate relative to an origin of the virtual coordinate system.

[0008] The document DE 10 2015 118 302 A1 shows a lighting device for vehicles in which light sources are designed as raster light sources which can be controlled in a group such that a raster signature is generated in a raster field.

[0009] The publication DE 10 2011 119 230 B4 discloses a motor vehicle indicator light with LEDs divided into LED groups. When the indicator light is switched on, the LED groups are switched on one after the other.

[0010] The object of the invention is to provide a method for operating a lighting device which enables flexible control of the lighting units of the lighting device.

[0011] This object is achieved by the method according to claim 1 or the lighting device according to claim 10. Further developments of the invention are defined in the dependent claims.

[0012] The method according to the invention serves to operate a lighting device in a motor vehicle. Depending on the design, the lighting device can be interior lighting, such as ambient interior lighting, or possibly also exterior lighting on the outside of the motor vehicle. The lighting device comprises a plurality of lighting units that are connected to a communication bus in the motor vehicle and receive messages sequentially from a control unit via the communication bus. The lighting units of the plurality of lighting units are divided into a plurality of groups, each consisting of one or more lighting units, and each message is assigned to a group. Lighting units can also be assigned to a plurality of different groups, if necessary. However, the groups are preferably disjoint, so that each lighting unit is assigned to exactly one group.

[0013] Each message transmitted over the communication bus specifies one or more operating parameters (i.e., corresponding operating parameter values) for an individual lighting unit. A respective lighting unit in the assigned group of a received message performs its operation based on the operating parameter(s) from the received message, i.e., the respective lighting unit uses at least some of the operating parameters from the message for its operation. All lighting units not belonging to the group of the received message ignore the operating parameters in the message and continue operating based on the currently set operating parameters.

[0014] The method according to the invention is characterized in that the control unit changes the division of the plurality of lighting units into groups at least once during operation of the lighting device. In this way, the light distribution generated by the lighting device can be adapted very flexibly by changing the group assignments of corresponding lighting units. This significantly expands the possibilities for creating different lighting scenarios.

[0015] In a preferred embodiment, the plurality of lighting units comprises one or more LED units, each comprising one or more LEDs. Preferably, all of the lighting units of the plurality of lighting units are LED units. Particularly preferably, the LED units are so-called RGB LED units, which comprise a red, green, and blue LED and can generate different colors by appropriately controlling these LEDs. Nevertheless, the lighting units can also comprise other types of lighting units than LED units. For example, at least some of the lighting units can also comprise laser light units, each comprising one or more laser diodes.

[0016] In a further preferred embodiment of the method according to the invention, a group that is modified by changing the division of the plurality of lighting units into groups replaces the group valid before the modification. This is achieved by deleting the group valid before the modification by the control unit. In this way, the memory space required on the control unit for defining the groups is used efficiently.

[0017] In a further preferred embodiment of the method according to the invention, the messages are transmitted by the control unit in such a way that messages are received from each lighting unit at intervals below a threshold value, which messages are assigned to a group in which the respective lighting unit is located. This takes into account that lighting units often require a signal at predetermined minimum intervals, otherwise they will switch off. Accordingly, messages may also be sent to lighting units that do not cause a change in the current operating parameters but are required to prevent the corresponding lighting unit from switching off.

[0018] In a further preferred embodiment, the control unit of the lighting device according to the invention controls the transmission of messages such that messages that cause a change in at least one operating parameter of at least one lighting unit are prioritized over messages that do not lead to any change in the operating parameters of the lighting units. This ensures that changes in the operation of the lighting units are quickly visible.

[0019] Depending on the design, the number of operating parameters can contain different variables. Preferably, the number of operating parameters includes a target brightness at which a lighting unit should emit light. The lighting units can thus vary their brightness. Preferably, the number of operating parameters also includes a time period that determines the duration of the change to the target brightness.

[0020] In a further variant of the method according to the invention, the number of operating parameters comprises a target color in which a lighting unit is to emit light, wherein the number of operating parameters preferably also contains a time period that determines the duration of the change to the target color. The above terms target brightness or target color or time period are to be understood broadly. In particular, these variables may not be directly represented in the corresponding message by corresponding brightness or color or time values, but rather by variables (such as indices) that are assigned to such values. If, in the above embodiments, the lighting unit addressed by the message is already set to the target brightness or target color of the received message, the corresponding time periods of the brightness or color change in the lighting unit are disregarded.

[0021] The communication bus used in the method according to the invention for transmitting messages can be based on various technologies. In a particularly preferred embodiment, it is the well-known LIN bus.

[0022] In addition to the method described above, the invention relates to a lighting device for a motor vehicle, which comprises a plurality of lighting units connected to a communication bus that is installed in the motor vehicle during operation of the lighting device. The lighting device comprises a control unit that, during operation of the lighting device, successively transmits messages that are received via the communication bus by the lighting units of the plurality of lighting units. During operation of the lighting device, the lighting units of the plurality of lighting units are divided into several groups, each consisting of one or more lighting units, and each message is assigned to a group.Each message specifies one or more operating parameters, and a lighting unit in the assigned group of a received message performs its operation based on the operating parameter(s) from the received message. The lighting device according to the invention is characterized in that the control unit is configured to change the division of the plurality of lighting units into groups at least once during operation of the lighting device.

[0023] In a preferred embodiment, the lighting device according to the invention is designed to carry out one or more preferred variants of the method according to the invention.

[0024] The invention further relates to a motor vehicle which comprises one or more lighting devices according to the invention or according to one or more preferred embodiments of the invention.

[0025] Embodiments of the invention are described in detail below with reference to the attached figures.

[0026] They show: Fig. 1 a schematic representation of an embodiment of a lighting device according to the invention; Fig. 2 is a schematic representation of a message displayed in the lighting device of the Fig. 1 is sent from the control unit to the communication bus; and Fig. 3 a schematic representation which illustrates by way of example the change in the division of lighting units into groups according to the invention.

[0027] An embodiment of the invention is described below with reference to a lighting device in a motor vehicle, which comprises a plurality of LED units as lighting units. The lighting device is preferably an ambient interior lighting system. The LED units are shown in the schematic representation of the Fig. 1 is designated LE1, LE2, ..., LE26. In other words, the lighting device contains 26 LED units. These LED units are connected to a control unit or control device 1 via a communication bus 2 in the form of a LIN bus. Due to the use of the LIN bus, no more than 26 lighting units can be operated in the lighting device for technical reasons. In the embodiment described here, the LED units are RGB LED units, which contain a red, green, and blue LED and can generate different colors by appropriately mixing the colors of these LEDs. Furthermore, the brightness of the LEDs and thus the overall brightness of the RGB LED units can be varied.

[0028] The LED units LE1 to LE26 are controlled via messages ME (see Fig. 2) which are generated in the control unit 1 at regular intervals (e.g. 10 ms), i.e. with a predetermined update rate, and sent to the LIN bus 2 so that all LED units receive the messages. In the embodiment described here, the LED units are divided into disjoint groups, i.e. each LED unit is uniquely assigned to a group of one or more LED units. The division into groups is carried out by the control unit. Each transmitted message ME is assigned to a group and enables the simultaneous control of all LED units in the group, provided that the corresponding operating parameters of the respective LED units in the group are changed in the same way. Those LED units which are not in the group of the respective received message ignore the content of the message.

[0029] Fig. Figure 2 shows schematically the format of the light source used in the lighting device of Fig. 1 used messages ME. The message ME shown includes a bit mask BM, in which each of the 26 LED units is assigned a bit. The bit mask determines the LED units' membership in the corresponding group assigned to the message ME. A bit with the value "1" indicates, in the order of the numbering of the LED units, that the corresponding LED unit belongs to the group that is to be addressed with the message ME. In the example shown in Fig. The message ME shown in Figure 2 includes, among others, the LED unit LE1 and the LED unit LE26 in the corresponding group.

[0030] The ME message contains the additional fields F1 to F4. Field F1 specifies a color value FB to which each LED unit in the group should be set upon receipt of the ME message. In contrast, field F2 specifies a brightness value HE to which each LED unit in the group should be set. Field F3 specifies the duration TFB of the change to the target color FB for each LED unit in the group. If the LED unit is already set to the target color, this parameter is not processed further because the LED unit does not need to perform a color change. Field F4 specifies the duration THE of the change to the target brightness HE for each LED unit in the group. If the LED unit already has the target brightness, this value is not taken into account by the LED unit because the target brightness has already been set.

[0031] Conventionally, the distribution of the LED units into groups in the control unit 1 is statically predefined and cannot be changed during operation of the lighting device. Consequently, the possibilities for dynamic color changes are limited, since only fixed groups of LED units can change their operating parameters with corresponding messages.

[0032] In order to expand the possibilities of different lighting scenarios, it is proposed according to the invention to change the grouping of the LED units dynamically during operation of the lighting device by means of the control unit 1. For example, in Fig. 3 such a dynamic grouping for the lighting device of the Fig. 1. For reasons of clarity, the grouping is only indicated for some of the LED units, namely for the LED units LE1 to LE8. Initially, the grouping is defined by the control unit 1 in such a way that the LED units LE1, LE2, LE7 and LE8 form a group G1, the LED units LE2, LE3 and LE5 form a group G2 and the individual LED unit LE6 forms a group G3. The respective LED units of a group are always addressed by messages belonging to the group and can therefore only change their operating parameters together. The affiliation of the LED units to a group is specified via the bit pattern BM of the message. This message is not relevant for all LED units that are not in the group of the corresponding message according to the bit pattern BM. The message is therefore not further processed in these LED units.

[0033] At a certain point in time, it is desired that the LED units be grouped differently, i.e., different combinations of LED units with the same operating parameters are to be controlled. An algorithm is stored in control unit 1 that dynamically adjusts the corresponding grouping of the lighting units depending on certain events, such as an operator action performed by the driver to change a lighting scenario. Fig. 3 shows an example of a regrouping of LED units indicated by the arrow AR. In control unit 1, a change in the distribution of the groups is achieved by changing the bit pattern BM of the corresponding messages. In the scenario of Fig.3, group G1 now only contains LED units LE1, LE2, and LE8. LED unit LE7 has been moved to group G2, which now contains the three LED units LE2, LE3, and LE7. In contrast, LED unit LE5, which was originally contained in group G2, is to be controlled separately from the other LED units, forming a new group G4 with the single LED unit LE5. The regrouping has no effect on LED unit LE6, meaning LED unit LE6 remains in group G3.

[0034] According to the embodiment just described, it is no longer statically specified which LED units are in which group. It is therefore no longer predefined which LED units should look or behave the same at all times. Instead, the appearance and behavior in a specific situation can be defined individually for each LED unit. An algorithm in the control unit dynamically groups all LED units into groups to which the same properties are assigned according to the corresponding operating parameters in the messages. If, for example, the color value of an LED unit is to change, the algorithm decides whether this LED unit can remain in its existing group or be assigned to an existing group with the same appearance, or whether a new group is created in which this LED unit is sorted. If the LED unit is assigned to a new group, it is simultaneously removed from the previous group.

[0035] The LED units used in the embodiment just described generally require a signal after a certain maximum time has elapsed (e.g., 4 seconds), otherwise they would switch off. Accordingly, the control of the LED units LE1 to LE26 by the control unit 1 is configured such that each LED unit receives a message before the expiration of this maximum time, even if the message contains operating parameters that are identical to the current operating parameters of the corresponding LED unit. Furthermore, to ensure that changes to the operating parameters of an LED unit become visible as quickly as possible, the control unit 1 prioritizes messages. Messages are prioritized for groups that contain LED units whose operating parameters are changed by the corresponding message.In other words, such messages have a higher priority than messages which leave the operating parameters of the LED units of the corresponding group unchanged, but are necessary to avoid switching off the LED units if the above maximum time is exceeded.

[0036] The embodiments of the invention described above have a number of advantages. In particular, by varying the distribution of lighting units into groups, dynamic or flowing light can be generated, which is perceived as pleasant. The dynamic grouping of lighting units also allows for greater flexibility in defining lighting scenarios, since different lighting units can participate in each lighting scenario and the same subsets of lighting units do not always have to have the same appearance or behavior. By appropriately grouping the lighting units, it can also be ensured that when a user manually changes a lighting scenario, there is no noticeable delay between the manual change and the actual switching of the lighting units. List of reference symbols 1 control unit 2 LIN bus LE1, LE2, ..., LE26 lighting units ME message BM bitmask FB, HE, TFB, THE operating parameters F1, F2, F3, F4 fields G1, G2, G3, G4 groups AR Arrow

Claims

[1] Method for operating a lighting device in a motor vehicle, wherein the lighting device comprises a plurality of lighting units (LE1, LE2, ..., LE26) which are connected to a communication bus (2) in the motor vehicle and receive messages (ME) sequentially from a control unit (1) via the communication bus (2), wherein the lighting units (LE1, LE2, ..., LE26) of the plurality of lighting units (LE1, LE2, ..., LE26) are divided into several groups (G1, G2, G3, G4) each consisting of one or more lighting units (LE1, LE2, ..., LE26), and each message (ME) is assigned a group (G1, G2, G3, G4), wherein each message (ME) specifies one or more operating parameters (FB, HE, TFB, THE) for an individual lighting unit (LE1, LE2, ..., LE26) and a respective lighting unit (LE1, LE2, ..., LE26) which is in the assigned group (G1, G2, G3, G4) of a received message (ME), performs its operation based on the operating parameter(s) (FB, HE, TFB, THE) from the received message (ME), . characterized by that the control unit (1) changes the division of the plurality of lighting units (LE1, LE2, ..., LE26) into groups (G1, G2, G3, G4) at least once during operation of the lighting device. [2] Method according to claim 1, characterized by that the plurality of lighting units (LE1, LE2, ..., LE26) comprises one or more LED units each comprising one or more LEDs, wherein the LED unit or LED units are preferably RGB LED units. [3] Method according to claim 1 or 2, characterized bythat a group (G1, G2, G3, G4) which is modified by changing the division of the plurality of lighting units (LE1, LE2, ..., LE26) into groups (G1, G2, G3, G4) replaces the group (G1, G2, G3, G4) valid before the modification by deleting the group (G1, G2, G3, G4) valid before the modification by the control unit (1). [4] Method according to one of the preceding claims, characterized by that the messages (ME) are transmitted by the control unit (1) in such a way that messages (ME) are received by each lighting unit (LE1, LE2, ..., LE26) at time intervals below a threshold value, to which a group (G1, G2, G3, G4) is assigned, in which the respective lighting unit (LE1, LE2, ..., LE26) is located. [5] Method according to one of the preceding claims, characterized bythat the control unit (1) controls the transmission of the messages (ME) in such a way that messages (ME) which cause the change of at least one operating parameter (FB, HE, TFB, THE) of at least one lighting unit (LE1, LE2, ..., LE26) are prioritized over those messages (ME) which do not lead to any change in operating parameters (FB, HE, TFB, THE) of the lighting units (LE1, LE2, ..., LE26). [6] Method according to one of the preceding claims, characterized by that the number of operating parameters (FB, HE, TFB, THE) comprises a target brightness (HE) with which a lighting unit (LE1, LE2, ..., LE26) is to emit light, wherein the number of operating parameters (FB, HE, TFB, THE) preferably also contains a time period (THE) which determines the maximum duration of the change to the target brightness (HE). [7] Method according to one of the preceding claims, characterized bythat the number of operating parameters (FB, HE, TFB, THE) comprises a target color (FB) in which a lighting unit (LE1, LE2, ..., LE26) is to emit light, wherein the number of operating parameters (FB, HE, TFB, THE) preferably also contains a time period (TFB) which determines the duration of the change to the target color (FB). [8] Method according to one of the preceding claims, characterized by that the communication bus (2) is a LIN bus. [9] Method according to one of the preceding claims, characterized by that the lighting device is an interior light in the motor vehicle or an exterior light on the outside of the motor vehicle. [10] Lighting device for a motor vehicle, which comprises a plurality of lighting units (LE1, LE2, ..., LE26) which are connected to a communication bus (2) which is installed in the motor vehicle during operation of the lighting device, wherein the lighting device comprises a control unit (1) which, during operation of the lighting device, successively transmits messages (ME) which are received via the communication bus (2) by the lighting units (LE1, LE2, ..., LE26) of the plurality of lighting units (LE1, LE2, ..., LE26), wherein, during operation of the lighting device, the lighting units (LE1, LE2, ..., LE26) of the plurality of lighting units (LE1, LE2...., LE26) are divided into a plurality of groups (G1, G2, G3, G4) each comprising one or more lighting units (LE1, LE2...., LE26) and each message (ME) is assigned a group (G1, G2, G3, G4), wherein each message (ME) specifies one or more operating parameters (FB, HE, TFB, THE) for an individual lighting unit (LE1, LE2...., LE26) and a respective lighting unit (LE1, LE2...., LE26) which is in the assigned group (G1, G2, G3, G4) of a received message (ME) carries out its operation based on the one or more operating parameters (FB, HE, TFB, THE) from the received message (ME). characterized by that the control unit (1) is designed such that it changes the division of the plurality of lighting units (LE1, LE2, ..., LE26) into groups (G1, G2, G3, G4) at least once during operation of the lighting device. [11] Lighting device according to claim 10, characterized by that the lighting device is designed to carry out a method according to one of claims 2 to 9. [12] Motor vehicle comprising one or more lighting devices according to claim 10 or 11.

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