Method for controlling the light emission of a vehicle's headlight

Abstract

Method (200) for controlling the light emission of at least one headlight (190) of a vehicle (100), wherein the vehicle (100) has a traffic sign recognition device (110), the method (200) comprising the following steps: Receiving (210) at least one traffic sign recognition signal from an interface to the traffic sign recognition device (110), wherein the at least one traffic sign recognition signal represents a traffic sign recognized in a road section currently being traveled by the vehicle (100); Evaluating at least one traffic sign recognition signal to determine at least one characteristic of the road currently being traveled by the vehicle (100); Setting (220) a debounce time and / or debounce distance for a change in the light emission of the at least one headlight (190) between a first emission characteristic and a second emission characteristic as a function of the at least one traffic sign recognition signal, wherein the debounce time and / or debounce distance is set as a function of the at least one traffic sign recognition signal; and Delaying (230) the change in the light emission of the at least one headlight (190) by the set debounce time and / or debounce distance in order to control the light emission of the at least one headlight (190).

Description

State of the art

[0001] The present invention relates to a method for controlling the light emission of a headlight of a vehicle, to a device configured to perform the steps of such a method, and to a computer program product with program code stored on a machine-readable medium for carrying out such a method when the program is executed on a device.

[0002] In a vehicle's high-beam assist system, debounce times and distances are used to delay the activation of the high beams. Generally, a certain debounce time or distance is incorporated into a high-beam assist system to prevent a vehicle that disappears around a bend, for example, from being blinded when it reappears. Debounce is generally required in all high-beam assist systems.

[0003] DE 10 2008 053 ​​945 A1 describes a headlight arrangement for a vehicle in which the lighting axes of the headlights can be swivelled laterally in order to change a common beam characteristic of the headlights.

[0004] DE 10 2005 027 887 A1 discloses a method and a device for informing a driver, whereby the vehicle light is adjusted when a recognized traffic sign requires an adjustment of the vehicle light.

[0005] DE 10 2009 028 344 A1 describes a method and a device for debouncing at least two changes in light characteristics, wherein a time interval between the at least two changes in light characteristics is determined, wherein a spatial distance between the at least two changes in light characteristics is determined from the time interval between the at least two changes in light characteristics based on the speed of the vehicle, wherein the debouncing is based on the spatial distance. Disclosure of the invention

[0006] Against this background, the present invention presents a method for controlling the light emission of a vehicle headlight, a device configured to perform the steps of such a method, and a computer program product with program code stored on a machine-readable medium for carrying out such a method when the program is executed on a device, according to the independent and dependent claims. Advantageous embodiments are described in the respective dependent claims and the following description.

[0007] The present invention provides a method for controlling the light emission of at least one headlight of a vehicle, wherein the vehicle has a traffic sign recognition device, and wherein the method comprises the following steps: Receiving at least one traffic sign recognition signal from an interface to the traffic sign recognition device, wherein the at least one traffic sign recognition signal represents a traffic sign recognized in a road section currently being traveled by the vehicle;

[0008] Setting a debounce time and / or debounce distance for changing the light emission of at least one headlight between a first beam pattern and a second beam pattern depending on the at least one traffic sign recognition signal; and

[0009] Delaying the change in the light output of at least one headlight by the set debounce time and / or debounce distance in order to control the light output of at least one headlight.

[0010] The vehicle in question can be a motor vehicle, in particular a road-bound motor vehicle, such as a passenger car, truck, passenger transport vehicle, or other commercial vehicle. The at least one headlight can be, for example, the vehicle's front headlight. The headlight's light output can be adjustable in steps or continuously. The headlight's light output can be modified with respect to its beam pattern. This beam pattern can include brightness, a beam angle, and / or other characteristics. For example, the first beam pattern might correspond to a lower illuminance or range than the second beam pattern.The headlight's light output can be changed from the first beam pattern to the second beam pattern, or vice versa. For example, the first beam pattern can correspond to or be similar to a low beam or similar, and the second beam pattern can correspond to or be similar to a high beam or similar. The traffic sign recognition system can include a camera facing forward, an image processing unit, and / or similar components. The traffic sign recognition system generates the traffic sign recognition signal. This signal indicates which traffic sign has been detected by the system on the road currently being traveled by the vehicle.The traffic sign recognition signal can, for example, represent the type of traffic sign and the specific traffic sign in question. The traffic sign recognition signal must uniquely represent the traffic sign. The traffic sign can be a road sign, a traffic signal, and / or a road marking, but also street lighting or guideposts. Traffic signs can include prohibition signs, mandatory signs, warning signs, directional signs, town / city signs, and the like. The outline, symbols, and / or lettering of the traffic sign can be recognized and represented in the traffic sign recognition signal. The debounce time represents a form of hysteresis. The debounce time can be understood, for example, as the delay in the change in the light output of the headlight between the first and second beam characteristics.The debounce time can be shortened or lengthened during the adjustment process relative to a previously set value or a preset value. A debounce distance can be understood as a speed-dependent debounce time. For example, when the vehicle is stationary, the debounce time can be arbitrarily long. A debounce distance is thus essentially a waiting distance that should be driven until the headlight switches to a different beam pattern; therefore, the debounce distance is comparable to a debounce time, but taking into account the vehicle's current movement.

[0011] The present invention further provides a device configured to perform or implement the steps of the method according to the invention. In particular, the device can include components configured to perform each step of the method. This embodiment of the invention in the form of a device also allows the problem underlying the invention to be solved quickly and efficiently.

[0012] In this context, a device can be understood as an electrical device or control unit that processes sensor signals and outputs control signals accordingly. The device can have an interface, which may be implemented in hardware and / or software. In the case of a hardware-based interface, the interfaces can, for example, be part of a so-called system ASIC, which incorporates various functions of the device. However, it is also possible that the interfaces are separate integrated circuits or at least partially comprised of discrete components. In the case of a software-based interface, the interfaces can be software modules, which, for example, are located on a microcontroller alongside other software modules.

[0013] It is also advantageous to have a computer program product with program code stored on a machine-readable medium such as semiconductor memory, hard disk memory or optical memory, and used to carry out the method according to one of the embodiments described above, when the program is executed on a device.

[0014] The invention is based on the finding that, when controlling the light output of at least one headlight of a vehicle, the change in the light output of the at least one headlight between a first beam pattern and a second beam pattern can be improved by setting a debounce time and / or debounce distance applicable to the change based on traffic signs. Thus, traffic sign recognition is used to set the debounce time and / or debounce distance of the at least one headlight. The light output of the at least one headlight can then be advantageously controlled based on the set debounce time and / or debounce distance.

[0015] An advantage of the present invention lies in the fact that the road situation or road layout can be reliably and accurately deduced from a recognized traffic sign, since road construction regulations lead to uniform signage. The debounce time and / or debounce distance serves, for example, as a waiting period or distance before the high beams are activated, thus preventing glare for other vehicles. Furthermore, excessively frequent changes in light emission, such as frequent switching between high and low beams, can be avoided. This also reduces the disruptive influence of frequent changes in light emission on the driver and therefore increases driving safety. With the debounce time and / or debounce distance, an advantageous compromise between visibility and prophylactic glare prevention can be achieved by incorporating traffic sign recognition.

[0016] The process also includes an evaluation step of at least one traffic sign recognition signal to determine at least one characteristic of the road currently being traveled by the vehicle. This characteristic could, for example, be the gradient or slope of the road, the presence of at least one curve, and so on. During this evaluation step, the at least one traffic sign recognition signal can be analyzed, interpreted, or otherwise processed. For example, signal waveforms and their properties can be stored in a reference table. A signal waveform of the at least one traffic sign recognition signal can then be compared with the reference signal waveforms to identify the correct characteristic.This embodiment offers the advantage that features of the road layout, which have a significant influence on the control of light emission and therefore have great significance and relevance, can be used.

[0017] In this context, at least one characteristic of the road alignment currently being traveled by the vehicle can be a road alignment-related sight distance and / or a design speed for the road alignment currently being traveled. Road design is carried out according to the guidelines for road layout based on the so-called design speed. The design speed influences a whole range of parameters in the road design. These include, for example, minimum curve radius, clothoid parameters, maximum straight section length, maximum longitudinal gradient, minimum crest and dip radii, and cross slope. All these parameters are important for the visibility or sight distance in the current road alignment. Therefore, if the design speed of the current road alignment is known, the visibility or sight distance in front of the vehicle can be determined.This embodiment offers the advantage that the control of the light emission is based on a meaningful, reliable and predictive basis.

[0018] Furthermore, a step involving assigning a setting value to at least one traffic sign recognition signal can be provided, based on at least one property of the road currently being traveled by the vehicle. In the setting step, the debounce time and / or debounce distance is set depending on the at least one traffic sign recognition signal and can additionally be adjusted based on the setting value assigned to that signal. Depending on the road property determined in the evaluation step, the setting value can shorten, lengthen, or maintain the debounce time in the setting step. Visibility can vary depending on the landscape. For example, on a flat, treeless plain with a straight road, vehicles are detected from a distance. In this case, a short debounce time and / or debounce distance can generally be selected.The settings can be adjusted. On a winding, hilly road with trees or other obstructions, for example, a longer debounce time and / or debounce distance can be selected or set, as other vehicles may suddenly appear near the vehicle. This design offers the advantage that the relevant and significant characteristics of the road's course can be easily taken into account when setting the debounce time and / or debounce distance.

[0019] During the reception step, at least one additional traffic sign recognition signal can be received from an interface to the traffic sign recognition device, where this at least one additional traffic sign recognition signal represents at least one further traffic sign detected in a section of road currently being traveled by the vehicle. During the setting step, the debounce time and / or debounce distance can also be set depending on the traffic sign recognition signal and the at least one additional traffic sign recognition signal. As the vehicle travels along a section of road, several traffic signs can be detected sequentially, and thus several traffic sign recognition signals can be received.This embodiment offers the advantage that multiple traffic signs can influence the debounce time and / or debounce distance via the traffic sign recognition signal, and at least one further traffic sign recognition signal can influence this during the setting step. Thus, the control of the light emission can more accurately reflect the current situation along the road.

[0020] This process may include a step of combining the traffic sign recognition signal with at least one other traffic sign recognition signal to generate a combined traffic sign recognition signal. During this adjustment step, the debounce time and / or the debounce distance can be set depending on the combined traffic sign recognition signal. The combination step can also involve a logical interaction of the signals. Furthermore, the combination step can be combined with an evaluation step. In this case, the combination step can be performed based on evaluated properties of the traffic sign recognition signals. Based on these evaluated properties, a suitable method for combining the traffic sign recognition signals can be determined.This embodiment offers the advantage that, via the combined traffic sign recognition signal, traffic signs – especially those occurring in quick succession – can be taken into account to varying degrees during the setting step, depending on the characteristics of the road course that can be deduced from it.

[0021] According to one embodiment, the debounce time and / or debounce distance can be set during the adjustment step, depending on the traffic sign recognition signal and on vehicle driving data and / or environmental information. The driving data can include vehicle speed, yaw rate, and / or the like. The environmental information can include the number of oncoming vehicles, navigation system data, lane detection, and / or the like. The debounce time and / or debounce distance can be fixed, dependent on the vehicle's own movement (e.g., speed-dependent, yaw rate-dependent, etc.), or adjusted based on situations in the vehicle's environment. For example, if a single vehicle is approaching from the opposite direction, the debounce time and / or debounce distance can be shortened, thus allowing the high beams to activate more quickly.Visibility along the current road can also be determined by analyzing map data, possibly enhanced with special techniques, such as that from a navigation system (if available), as the road's course is clearly visible and easily estimated in this context. This effectively creates a virtual sensor. This approach offers the advantage of allowing the debounce time to be adjusted even more precisely to the current traffic and road conditions. This improves the balance between visibility and glare reduction.

[0022] According to another embodiment, a step of checking the plausibility of the set debounce time using vehicle driving data and / or environmental information may be provided, followed by a step of correcting the set debounce time and / or debounce distance based on the vehicle driving data and / or environmental information if the check step reveals a lack of plausibility. The vehicle driving data and / or environmental information can be used to validate the debounce time and / or debounce distance set based on the traffic sign recognition signal. For example, if lane detection suggests a straight road, the debounce time and / or debounce distance can be set slightly higher. Similarly, solid lane markings in the center indicate a no-overtaking zone.The length of the lane marking lines can also be used as an indicator of the design speed, since the line length increases with the vehicle speed. This embodiment offers the advantage that the debounce time and / or debounce distance can be set even more precisely, reliably, and situationally appropriately.

[0023] The invention is explained in more detail by way of example with reference to the accompanying drawings. These show: Fig. 1 a schematic representation of a vehicle with a control device according to an embodiment of the present invention; Fig. 2 a flowchart of a method according to an embodiment of the present invention; and Fig. 3, Fig. 4, Fig. 5, Fig. 6, Fig. 7 to Fig. 8 illustrations of various traffic signs.

[0024] Identical or similar elements in the figures may be identified by identical or similar reference numerals, without the need for repeated descriptions. Furthermore, the figures of the drawings, their description, and the claims contain numerous features in combination. It is clear to a person skilled in the art that these features can also be considered individually or combined into further combinations not explicitly described here. Furthermore, the invention is explained in the following description, possibly using different measurements and dimensions, but the invention is not to be understood as limited to these measurements and dimensions. Moreover, process steps according to the invention can be repeated and carried out in a different sequence than described.If an embodiment includes an “and / or” connection between a first feature / step and a second feature / step, this can be interpreted as meaning that the embodiment according to one embodiment has both the first feature / step and the second feature / step, and according to another embodiment either only the first feature / step or only the second feature / step.

[0025] Fig. Figure 1 shows a schematic representation of a vehicle 100 with a control device according to an embodiment of the present invention. The vehicle 100 has a traffic sign recognition device 110, a control device 120, a receiver 130, an adjustment device 140, a delay device 150, and two headlights 190. The traffic sign recognition device 110 is connected to the control device 120, for example, via at least one signal line. The two headlights 190 are also connected to the control device 120, for example, via at least one signal line. The control device 120 is connected between the traffic sign recognition device 110 and the two headlights 190. The control device 120 includes the receiver 130, the adjustment device 140, and the delay device 150.

[0026] The traffic sign recognition device 110 may, for example, include a camera and / or image processing electronics. The traffic sign recognition device is designed to generate at least one traffic sign recognition signal, representing a traffic sign detected in a section of road currently being traveled by the vehicle, and to output it to the control device 120.

[0027] The control device 120 is configured to control the light output of the headlights 190 of the vehicle 100. In particular, the control device 120 is configured to control the light output of the headlights 190 of the vehicle 100 with respect to a bounce time and / or bounce distance. The receiver 130, the adjustment device 140, and the delay device 150 of the control device 120 are interconnected. More precisely, the receiver 130 is connected to the adjustment device 140, and the delay device 150 is connected to the adjustment device 140. Thus, the adjustment device 140 is connected between the receiver 130 and the delay device 150.

[0028] The receiver 130 of the control device 120 is configured to receive at least one traffic sign recognition signal from the traffic sign recognition device 110. The receiver 130 can output the at least one received traffic sign recognition signal to the setting device 140.

[0029] The adjustment device 140 can receive at least one traffic sign recognition signal from the receiver 130. The adjustment device 140 is configured to set a debounce time and / or debounce distance for a change in the light emission of the headlights 190 between a first emission characteristic and a second emission characteristic, depending on the at least one traffic sign recognition signal. For example, the change in the light emission of the headlights 190 could be a high beam operation or the like. The adjustment device 140 can output the set debounce time and / or debounce distance to the delay device 150 in the form of a signal.

[0030] The delay device 150 can receive the set debounce time from the adjustment device 140. The delay device 150 is designed to delay the change in the light output of the headlights 190 by the set debounce time and / or to extend the debounce distance. For this purpose, the delay device 150 can generate a delay value.

[0031] The control device 120 can output a control signal to the headlights 190. The control signal can include or take into account the delay value of the delay device 150. The control device 120 is designed to control the light output of the headlights 190 via the control signal.

[0032] The headlights 190 can receive the control signal from the control device 120. The control signal can cause the change in the light emission of the headlights 190 between the first beam pattern and the second beam pattern, taking into account the set debounce time, and thus the delay value, and / or the set debounce distance.

[0033] Fig. Figure 2 shows a flowchart of a method 200 for controlling the light emission of at least one headlight of a vehicle, according to an embodiment of the present invention. The vehicle is equipped with a traffic sign recognition device. The method 200 includes a step of receiving at least one traffic sign recognition signal 210 from an interface to the traffic sign recognition device. The at least one traffic sign recognition signal represents a traffic sign detected in a section of road currently being traveled by the vehicle. The method 200 also includes a step of setting a debounce time and / or debounce distance for changing the light emission of the at least one headlight between a first beam pattern and a second beam pattern as a function of the at least one traffic sign recognition signal.Method 200 finally comprises a step of delaying 230 the change in the light emission of the at least one headlight by the set debounce time and / or debounce distance in order to control the light emission of the at least one headlight. Method 200 can be used in conjunction with a device, such as the control device from . Fig. 1. Advantageously implemented. Thus, the control device can be made of Fig. 1 be trained to carry out the steps of procedure 200.

[0034] Fig. 3, Fig. 4, Fig. 5, Fig. 6, Fig. 7 to Fig. Figure 8 shows representations of signage using various traffic signs, whereby the design speed of the road currently being traveled by a vehicle can be inferred from the traffic signs. The traffic signs can be detected by a traffic sign recognition device, such as the traffic sign recognition device from Fig. 1, detected and by a device, such as the control device from Fig. 1. To control the light emission of at least one headlight of a vehicle. The device may employ a method such as the method described above. Fig. 2. Carry out. This involves setting a time for at least one headlight, based on the design speed of the road alignment.

[0035] Fig. Figure 3 shows speed-regulating traffic signs as an indication of the design speed. Fig. Figure 3 shows traffic signs for speed limits and / or cancellations of speed limits, as well as for recommended speeds and their cancellation, which can be evaluated to determine the design speed of the road. For example, the addition of "Noise Protection" to a speed limit sign can indicate that the design speed, and therefore the visibility, is higher than the stated maximum speed on the current road.

[0036] Fig. Figure 4 shows warning signs where the debounce time is preferably reduced because the design speed, as well as likely the visibility, is low in the current road alignment. This can be achieved by the following: Fig. The four warning signs shown will be evaluated. Fig. The four warning signs shown indicate a sharp bend, a tricky road layout, a slope, a risk of slipping, an intersection, and hilly terrain.

[0037] Fig. Figure 5 shows traffic signs for overtaking prohibitions, for the lifting of overtaking prohibitions, and for the general lifting of prohibitions and restrictions. Overtaking prohibitions are frequently found at points along the road with poor visibility, as the visibility for an overtaking maneuver is insufficient. The lifting of the overtaking prohibition indicates an increase in visibility. This can also be used to adjust the debounce time and / or debounce distance accordingly.

[0038] Fig. Figure 6 shows a rockfall warning sign and a construction site warning sign. Rocks only fall from high points or rock faces. High areas can reduce visibility on curves. Construction sites often have detours that are winding. Therefore, the rockfall warning sign and the construction site sign can be used to infer the design speed and visibility of the road ahead.

[0039] Fig. Figure 7 shows a general warning sign. Some traffic signs can be used differently when evaluating the design speed or visibility of the road ahead. A general warning sign, for example, could be used both to increase the debounce time to prevent glare when a poorly visible area is suspected, and to shorten the debounce time to increase visibility and allow the hazard to be recognized in time.

[0040] Fig. Figure 8 shows traffic signs indicating an intersection, roundabout, or junction. This can also provide information about the design speed or visibility of the road ahead.

[0041] Other signs can also be used to estimate or determine the design speed. These include, for example, town signs, road signs, directional signs for sharp curves, and the like.

[0042] The device and method for controlling the light emission of at least one headlight of a vehicle, according to exemplary embodiments of the present invention, could thus be integrated into existing high-beam assist systems and used in conjunction with them. In this context, debounce times and / or debounce distances for such a high-beam assist system are set based on traffic signs and the derived design speed and / or visibility. Sign recognition is therefore used to estimate visibility and set debounce times and / or debounce distances of headlight systems. Either, for example, the high beam and / or low beam, or the like, is set directly based on the signs, or the parameterization is adjusted differently so that the high beam and / or low beam, or the like, is also set depending on other influencing factors.

Claims

[1] Method (200) for controlling the light emission of at least one headlight (190) of a vehicle (100), wherein the vehicle (100) has a traffic sign recognition device (110), the method (200) comprising the following steps: Receiving (210) at least one traffic sign recognition signal from an interface to the traffic sign recognition device (110), wherein the at least one traffic sign recognition signal represents a traffic sign recognized in a road section currently being traveled by the vehicle (100); Evaluating at least one traffic sign recognition signal to determine at least one characteristic of the road currently being traveled by the vehicle (100); Setting (220) a debounce time and / or debounce distance for a change in the light emission of the at least one headlight (190) between a first emission characteristic and a second emission characteristic as a function of the at least one traffic sign recognition signal, wherein the debounce time and / or debounce distance is set as a function of the at least one traffic sign recognition signal; and Delaying (230) the change in the light emission of the at least one headlight (190) by the set debounce time and / or debounce distance in order to control the light emission of the at least one headlight (190). [2] Method (200) according to claim 1, characterized by , that at least one property of the road course currently traveled by the vehicle (100) has a road course-related visibility range and / or a design speed of the road course currently traveled by the vehicle (100). [3] Method (200) according to one of claims 1 to 2, characterized by a step of assigning a setting value to the at least one traffic sign recognition signal based on the at least one property of the road course currently travelled by the vehicle (100), wherein in the setting step (220) the debounce time and / or debounce distance is adjustable depending on the at least one traffic sign recognition signal and on the basis of the setting value assigned to the at least one traffic sign recognition signal. [4] Method (200) according to any one of the preceding claims, characterized by, that in the receiving step (210) at least one further traffic sign recognition signal is received from an interface to the traffic sign recognition device (110), wherein the at least one further traffic sign recognition signal represents at least one further traffic sign recognized in a road section currently being traveled by the vehicle (100), and that in the setting step (220) the debounce time and / or debounce distance is set depending on the traffic sign recognition signal and the at least one further traffic sign recognition signal. [5] Method (200) according to claim 4, characterized bya step of combining the traffic sign recognition signal and at least one other traffic sign recognition signal to generate a combined traffic sign recognition signal, wherein in the setting step (220) the debounce time and / or debounce distance is set depending on the combined traffic sign recognition signal. [6] Method (200) according to any one of the preceding claims, characterized by , that in the setting step (220) the debounce time and / or debounce distance is set depending on the traffic sign recognition signal and depending on vehicle driving data (100) and / or environmental information. [7] Method (200) according to any of the preceding claims, characterized bya step of checking the plausibility of the set debounce time and / or debounce distance based on vehicle driving data (100) and / or environmental information and a step of correcting the set debounce time and / or debounce distance based on the vehicle driving data (100) and / or environmental information if the check step reveals a lack of plausibility of the set debounce time and / or debounce distance. [8] Device (120) configured to perform the steps of the method (200) according to any one of claims 1 to 7. [9] Computer program product with program code stored on a machine-readable medium for carrying out the method (200) according to any one of claims 1 to 7 when the program is executed on a device (120).

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