Method and apparatus for analyzing the light emission of a vehicle headlight

Abstract

Method for analyzing a light emission (104) of a headlight (106) of a vehicle (100), the method comprising the following steps: Reading (401) a distance value representing a distance between the vehicle (100) and an object (110) located in the vicinity of the vehicle (100); Reading (403) an irradiance value representing the height of an area of ​​the object (110) illuminated by the light emission (104); and Determine (405) a luminous emission value characterizing (104) the light emission using the distance value and the irradiance value; characterized by a step of determining the irradiation value based on video-based object recognition and a predetermined dimension of the object (110) assigned to the object (110).

Description

State of the art

[0001] The present invention relates to a method for analyzing the light emission of a vehicle headlight, to a corresponding device, and to a corresponding computer program product.

[0002] If a vehicle's headlight beam is correctly adjusted, it can prevent dazzling other road users. Currently, there is no way to adjust a headlight's beam height except in a workshop. Such a headlight check can be performed in a workshop using a special headlight testing device. This device is positioned in front of the headlight while it is switched on to analyze its light output.

[0003] DE 10 2011 081 392 A1 discloses a method for determining the range of at least one headlight of a vehicle using at least one road marking feature that is illuminated by the at least one headlight and a distance between the vehicle and the at least one illuminated road marking feature.

[0004] DE 10 2008 025 458 A1 discloses a method for calibrating a horizontal light-dark boundary generated by at least one headlight of a vehicle. An image depicting an area in front of the vehicle is captured. The actual position of the horizontal light-dark boundary generated by at least one headlight of the vehicle is determined. If the actual position deviates from a preset target position, at least one correction value is calculated. Disclosure of the invention

[0005] Against this background, the approach presented here comprises a method for analyzing the light emission of a vehicle headlight, a device that uses this method, and finally a corresponding computer program product according to the main claims. Advantageous embodiments are described in the respective dependent claims and the following description.

[0006] Advantageously, an object located in the vicinity of a vehicle can be used to analyze the light emission from a headlight of the vehicle.

[0007] Such a procedure for analyzing the light emission of a vehicle's headlight comprises the following steps: Reading a distance value that represents a distance between the vehicle and an object located in the vicinity of the vehicle; Reading an irradiance value that represents the height of an area of ​​the object illuminated by the light emission; and

[0008] Determining a luminous emission value that characterizes the light emission using the distance value and the irradiance value.

[0009] The vehicle could be, for example, a passenger car, a truck, or any other type of vehicle. The headlight could be the vehicle's front headlight. The light emission could correspond to a cone of light emitted by the headlight when in operation. The object could be a traffic sign or an infrastructure element, such as a road marker post. A dimension of the object, particularly its height, may be known. The object could be located in front of the vehicle. Specifically, the object could be located within an area covered by the light emission, i.e., within an area illuminated by the headlight. The distance value could represent the distance between the object and a reference point of the vehicle. The distance value could, for example, specify the distance in meters.The irradiance value can specify the height of the illuminated area from the ground, for example, in centimeters. During the determination step, the irradiance value and the distance value can be related to each other to determine the luminous efficacy. Alternatively, the luminous efficacy can be determined using a predefined procedure that includes the irradiance value and the distance value as parameters. The luminous efficacy can be output via an interface. The luminous efficacy can be used, for example, to compare the current luminous efficacy of the spotlight with a target luminous efficacy, or to adjust the spotlight's luminous efficacy to the target luminous efficacy.

[0010] The procedure can include a step of reading a motion value. This motion value can represent the vehicle's acceleration or velocity. The determination step can be performed depending on the motion value. For example, the determination step can be performed only if the motion value indicates uniform vehicle motion. This prevents the light emission analysis from being distorted by a pitching motion of the vehicle caused by acceleration.

[0011] The procedure can include a step of reading a pitch value. The pitch value can represent a pitching motion of the vehicle. The determination step can be performed using the pitch value. This allows the analysis of light emission to be carried out even during non-uniform motion, for example, during vehicle acceleration.

[0012] In the step of reading the distance value, the distance value can be read via an interface to a vehicle's environmental sensing device. The environmental sensing device can be configured to detect objects within its detection range and determine their distance. Similarly, in the step of reading the irradiance value, the irradiance value can be read via an interface to a vehicle's object recognition device. The object recognition device can be configured to evaluate an image of the environment and, in particular, an image of the object, and to classify the object. This classification allows, for example, the assignment of a known height to the object.Furthermore, the object detection device can be configured to detect the illuminated area of ​​the object and to determine its dimensions, particularly its height, for example, using a detected dimension of the illuminated area, a detected dimension of the object, and a known dimension of the object associated with it. In this way, values ​​determined by known vehicle systems can be used to analyze the light emission.

[0013] For example, the procedure can include a step of determining the distance value based on radar-based distance measurement. Radar-based distance measurement allows for very precise distance determination. Alternatively, distance measurement can be performed using lidar, ultrasound, or stereo video measurement, for example.

[0014] The procedure can include a step of determining the irradiation value based on video-based object recognition and a predetermined dimension assigned to the object. Video-based object recognition, for example using a vehicle camera, allows for very precise object detection. This facilitates the assignment of the predetermined dimension to the object.

[0015] For example, in the step of determining the luminous efficacy, the luminous efficacy can be determined as the maximum range of the light emission. The maximum range can be easily calculated from the distance value and the irradiance value using a known installation height of the headlight.

[0016] In the step of determining the luminous efficacy, the luminous efficacy can also be defined as the height of the light emission associated with a given distance. Thus, the luminous efficacy can indicate the height of the light emission at a specific distance from the illuminator. This allows, for example, verification that the light emission at a given distance does not exceed a specified maximum height.

[0017] The procedure can include a step of comparing the luminous efficacy value with a predetermined target luminous efficacy value. The target luminous efficacy value can, for example, correspond to a specified luminous efficacy value. Such a comparison allows for easy verification of the headlight's current luminous efficacy. Depending on the result of this comparison, a beam pattern of the headlight that influences the luminous efficacy can, for example, be adjusted.

[0018] According to one embodiment, the method can include a step of adjusting the light output level using the light output value. This allows the vehicle to automatically adjust and / or correct the light output level using the processed information.

[0019] The steps of the procedure can be repeated multiple times. For example, the procedure can include at least one further step of reading another distance value, representing the distance between the vehicle and another object located in the vicinity of the vehicle; at least one further step of reading another irradiance value, representing the height of an area of ​​the other object illuminated by the light emission; and at least one further step of determining another light emission value that characterizes the light emission using the further distance value and the further irradiance value. This allows not only a single event, such as a post, but also multiple events to be used to verify the calculations for analyzing the light emission and to avoid incorrect settings regarding the light emission.

[0020] The method can, for example, include a step of filtering and / or averaging the light emission values ​​to determine a light emission value based on at least two individual values. Such an aggregated light emission value based on several individual values ​​can be further processed or used instead of a single value. This can increase the accuracy of the method. For example, the results of several calculations can be averaged or filtered so that the light emission is not adjusted for every event, but only gradually and imperceptibly to the driver.

[0021] A device for analyzing the light emission of a vehicle headlight has the following features: a reading device for reading a distance value that represents a distance between the vehicle and an object located in the vicinity of the vehicle; a reading device for reading an irradiance value that represents the height of an area of ​​the object illuminated by the light emission; and a determining device for determining a light emission value characterizing the light emission using the distance value and the irradiance value.

[0022] The approach presented here thus also creates a device designed to carry out or implement the steps of a variant of the method presented here in appropriate facilities. This embodiment of the invention in the form of a device also allows the problem underlying the invention to be solved quickly and efficiently.

[0023] In this context, a device can be understood as an electrical device that processes sensor signals and outputs control and / or data signals accordingly. The device may have an interface, which can 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 consist at least partially 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.

[0024] Also advantageous is a computer program product or computer program with program code that can be stored on a machine-readable carrier or storage medium such as a semiconductor memory, a hard disk memory or an optical memory and is used to carry out and / or control the steps of the method according to one of the embodiments described above, especially if the program product is executed on a computer or device.

[0025] The approach presented here is explained in more detail below using the attached drawings as examples. These show: Fig. 1 a schematic representation of a vehicle with a device for analyzing a light emission from a headlight of the vehicle according to an embodiment of the present invention; Fig. 2a to 2c schematic representations of a vehicle and an object according to an embodiment of the present invention; Fig. 3a to 3d schematic representations of a vehicle and an object according to an embodiment of the present invention; Fig. 4 a flowchart of a method according to an embodiment of the present invention; and Fig. Figure 5 shows a headlight inspection of a vehicle using a light testing device.

[0026] In the following description of favorable embodiments of the present invention, the same or similar reference numerals are used for the elements shown in the various figures and acting similarly, without repeating these elements.

[0027] Fig. Figure 1 shows a schematic representation of a vehicle 100 with a device 102 for analyzing a light emission 104 of a headlight 106 of the vehicle 100 according to an embodiment of the present invention.

[0028] The device 102 is configured to receive a distance value representing the distance between the vehicle 100 and an object 110 located in the vicinity of the vehicle 100. For this purpose, the device 102 has a reading device 112 for reading the distance value.

[0029] The device 102 is further configured to receive an irradiance value representing the height of an area of ​​the object illuminated by the light emission. For this purpose, the device 102 has a reading device 114 for reading the irradiance value.

[0030] The device 102 is further configured to determine a luminous emission value that characterizes the luminous emission 104. For this purpose, the device 102 has a determining device 116 for determining the luminous emission value. The determining device 116 is configured to determine the luminous emission value using the distance value and the irradiance value.

[0031] The device 102 is designed to provide the luminous efficacy value at an interface. The luminous efficacy value can, for example, define a range of the headlight 106, i.e., a maximum range of the light emission 104. The luminous efficacy value can also be a value determined from a combination of the distance value and the irradiance value. Such a luminous efficacy value can, for example, define a beam angle of the light emission 104 or a height of the light emission at a specific distance from the headlight 106.

[0032] According to one embodiment, the vehicle 100 has an environment sensing device 120. The environment sensing device 120 is configured to determine the distance value and provide it to the device 102. For this purpose, the environment sensing device 120 can be configured to evaluate a sensor signal from an environment sensor 122, for example, a radar system with a radar sensor for distance measurement.

[0033] According to one embodiment, the vehicle 100 has an object detection device 126. The object detection device 126 is configured to determine the distance value and provide it to the device 102. For this purpose, the object detection device 126 can be configured to evaluate a further sensor signal from another environmental sensor 128, for example, a video system with a video camera for detecting the environment of the vehicle 100.

[0034] According to one embodiment, the device 102 has an optional interface for reading a motion value, which, for example, represents an acceleration or change in speed of the vehicle 100 detected by an accelerometer 130. In this case, the device 102 can be configured to, for example, block the determination or output of the light emission value depending on the motion value, for instance, if an acceleration indicated by the motion value exceeds a threshold value.

[0035] According to one embodiment, the device 102 has an optional interface for reading a pitch value, which represents a pitching movement of the vehicle. The pitch value can, for example, also be provided by the acceleration sensor 130. The pitch value can, for example, be incorporated as a correction value into the determination of the light emission value in order to compensate for a change in the light emission 104 caused by the pitching movement.

[0036] According to one embodiment, an optional adjustment device 135 is provided, which is configured to determine a control signal for adjusting a characteristic of the light emission 104 using the light emission value and to use this signal for adjusting the headlight 106. To determine, for example, whether a correction of the headlight 106 setting is necessary, the adjustment device 135 can be configured, for example, to compare the light emission value with a stored target light emission value.

[0037] The Fig. Figures 2a to 2c show schematic representations of a vehicle 100 and an object 110 according to an embodiment of the present invention. The object 110 is, for example, a road marking arranged as a guidepost at the edge of a road. The vehicle 100 travels in the right lane of the road and moves towards the object 110. The vehicle 100 can be the one described in the illustration of Fig. 1 described vehicle which has a device for analyzing a light emission 104.

[0038] The light emission 104 of the vehicle 100 is produced in the form of a light cone by two headlights 106, 206, which are arranged at a leading edge 240 of the vehicle 100. The light emission 104 illuminates the area in front of the vehicle 100. According to this embodiment, the vehicle 100 is designed as a passenger car and in the Fig. 2a to 2c shown from above.

[0039] Instead of a guidepost as object 110, other standardized markings, e.g., a road sign, can also be used. According to this embodiment, object 110 has a standardized height. In an upper section, object 110, which is otherwise light in color, has a dark, for example, black, area. The height of the dark area can also be standardized.

[0040] In Fig. 2a. The object 110 is just outside the range of the light emission 104. A distance D1 exists between the object 110 and the leading edge 240 of the vehicle 100. According to this embodiment, the distance D1 represents the maximum range of the light emission 104.

[0041] In Fig. 2b The object 110 is partially illuminated by the light emission 104, for example, in a lower third or up to half its area. A distance D2 exists between the object 110 and the leading edge 240 of the vehicle 100. The height D2* of the area of ​​the object 110 illuminated by the light emission 104 is given in Fig. 2b marked.

[0042] The area detected by the light emission 104 thus appears bright and can therefore be detected by an object detection device of the vehicle 100. Furthermore, the object detection device can be configured to determine the height D2* of the detected area of ​​the object 110 and, for example, provide it as an irradiance value.

[0043] The distance D2 can be determined, for example, using an environment detection device 120 of the vehicle 100 and provided as a distance value.

[0044] In Fig. 2c, the object 110 is partially illuminated, for example in its lower two-thirds, by the light emission 104. According to this embodiment, the object 110 is illuminated by the headlights 106, 206 up to the height of the beginning of the dark upper section of the object 110.

[0045] There is a distance D3 between object 110 and the leading edge 240 of vehicle 100. The height D3* of the area of ​​object 110 illuminated by the light emission 104 is given in Fig. 2c marked.

[0046] Based on the Fig. Sections 2a to 2c below describe an embodiment of the invention in more detail.

[0047] According to the exemplary embodiment, the data from a video system with image recognition and a radar system are used together and compared against each other.

[0048] In the Fig. 2a to 2c, a road is recognizable from the perspective of a driver or the video system. The view over the front edge 240 of the hood onto the road is taken, and the lane markings 110 and the light output 104 of the headlights 106, 206 are recognized. In Fig. 2a The guidepost 110 is not yet illuminated by the headlight 104. Gradually, i.e., as the vehicle passes, more and more of the guidepost 110 is illuminated. Object recognition software of the video system is trained to recognize the guidepost 110 and determine its height (D1*, D2*, D3*), since the guidepost 110 is standardized. In the Fig. 3a to 3d these are referred to as heights H1, H2, H3.

[0049] According to one embodiment, the distance to other objects 110, e.g., stop or yield signs, can also be used. The distances at the respective times (D1, D2, D3) are determined from the radar system, as shown by the Fig. 3a to 3d are described.

[0050] Thus, it can be calculated whether the correct beam range of the headlights 106, 206 and in particular of the headlight 106 located on the side of object 110 is set.

[0051] The described approach can increase safety for the occupants of the vehicle 100, as well as for oncoming and preceding traffic. By adjusting the light height to the correct values, dazzling other road users is avoided, and the driver's own visibility is ensured when driving in the dark. According to one embodiment, the light intensity of the emitted light 104 can be monitored, and a warning signal can be issued, if necessary, to alert the driver.

[0052] The Fig. Figures 3a to 3d show schematic representations of a vehicle 100 and an object 110 according to an embodiment of the present invention. The vehicle 100 and the object 110 are shown from the side. Fig. Figures 3b to 3d show vehicle 100 being included in the Fig. Situations shown in 2a to 2c. Fig. 3a shows the vehicle 100 at an earlier time, at which the light emission 104 of the headlight 106 of the vehicle 100 ends in front of the object 100.

[0053] In the Fig. 3b to 3d are therefore the same times as in the Fig. Figures 2a to 2c show the vehicle 100 from the side. It can be seen that the light beam of the light emission 104 moves from left to right with the vehicle 100 and that the light of the light emission 104 illuminates the guidepost 110 as it passes.

[0054] Fig. Figure 3a shows the vehicle 100 at a time t=0 when the light 104 is still away from the post 110.

[0055] Fig. Figure 3b shows the vehicle 100 at time t=1 when the lower edge of the post 110, i.e. the ground, is reached.

[0056] Fig. Figure 3c shows vehicle 100 at time t=2, when it reaches the center of post 110. Vehicle 100 is at a distance D2 from object 110, and object 110 is illuminated up to a height H2.

[0057] Fig. Figure 3c shows vehicle 100 at time t=3, when the black part or section of post 110 is illuminated. Vehicle 100 is at a distance D3 from object 110, and object 110 is illuminated up to a height H3.

[0058] The Fig. Figures 3a to 3d thus show a schematic representation and parameters that can be used for distance detection of relevant objects according to an embodiment of the present invention.

[0059] According to one embodiment, it is further ensured by evaluating the speed and acceleration of the vehicle 100, e.g. with data from the ESP control unit or the navigation device of the vehicle 100, that the vehicle 100 drives uniformly, for example, that the acceleration a of the vehicle is equal to 0 or approximately equal to 0, and that a comparison can be permitted, i.e., for example, to carry out the steps of a method for analyzing the light emission 104.

[0060] According to one embodiment, the adjustment will always be allowed, however in this case the adjustment software is designed to also take into account the pitching of the vehicle 100 during acceleration and braking.

[0061] Thus, according to one embodiment, a device and a method for adjusting the luminous intensity of the light emission 104 when the vehicle 100 is in motion and for adjusting the longitudinal acceleration of the vehicle 100 are created.

[0062] Fig. Figure 4 shows a flowchart of a method for analyzing the light emission of a vehicle headlight according to an embodiment of the present invention. The steps of the method can be used, for example, in connection with devices of the in Fig. The vehicle shown in section 1 will be implemented.

[0063] In step 401, a distance value is read in, representing the distance between the vehicle and an object located in the vehicle's vicinity. Similarly, in step 403, an irradiance value is read in, representing the height of an area of ​​the object illuminated by the light emission. In step 405, a light emission value, characterizing the light emission, is determined using the distance value and the irradiance value.

[0064] Steps 401, 403, and 405 can be repeated to use multiple objects in the vicinity of the vehicle to determine a light emission value. For example, posts detected sequentially by the headlight's light emission can be used for this purpose.

[0065] Fig.Figure 5 shows a light test of a headlight 106 of a vehicle 100 using a special light test device 550 in a workshop. Such a test can, for example, be carried out in addition to, or replace, the analysis of the light emission of the headlight 106 described with reference to the preceding figures.

[0066] The described analysis, in which the light height or range of a motor vehicle can be adjusted while the vehicle is driving, eliminates the need to visit a workshop each time that has a corresponding device 550 for checking the headlights 106.

[0067] The embodiments described and shown in the figures are only examples. Different embodiments can be combined completely or with respect to individual features. An embodiment can also be supplemented by features from another embodiment.

[0068] Furthermore, the procedural steps presented here can be repeated and carried out in a different order than described.

[0069] If an embodiment includes an “and / or” connection between a first feature and a second feature, this is to be read as meaning that the embodiment according to one embodiment has both the first feature and the second feature, and according to another embodiment either only the first feature or only the second feature.

Claims

[1] Method for analyzing a light emission (104) of a headlight (106) of a vehicle (100), the method comprising the following steps: Reading (401) a distance value representing a distance between the vehicle (100) and an object (110) located in the vicinity of the vehicle (100); Reading (403) an irradiance value representing the height of an area of ​​the object (110) illuminated by the light emission (104); and Determine (405) a luminous emission value characterizing (104) the light emission using the distance value and the irradiance value; characterized by a step of determining the irradiation value based on video-based object recognition and a predetermined dimension of the object (110) assigned to the object (110). [2] Method according to claim 1, comprising a step of reading a motion value representing an acceleration or speed of the vehicle (100), and wherein the step of determining (405) is performed depending on the motion value. [3] Method according to one of the preceding claims, comprising a step of reading a pitch value representing a pitching motion of the vehicle (100), and wherein the step of determining (405) is performed using the pitch value. [4] Method according to one of the preceding claims, wherein in the step of reading (401) the distance value the distance value is read via an interface to an environment detection device (120) of the vehicle (100), and / or wherein in the step of reading (403) the irradiance value the irradiance value is read via an interface to an object detection device (126) of the vehicle (100). [5] Method according to one of the preceding claims, comprising a step of determining the distance value based on a radar-based distance measurement. [6] Method according to one of the preceding claims, wherein in the step of determining (405) the light emission value the light emission value is determined as a maximum luminous range of the light emission (104). [7] Method according to one of the preceding claims, wherein in the step of determining (405) the luminous emission value the luminous emission value is determined as a height of luminous emission (104) associated with a distance. [8] Method according to one of the preceding claims, comprising a step of comparing the light emission value with a predetermined target light emission value associated with a target light emission in order to check the light emission (104) of the headlight (106). [9] Method according to one of the preceding claims, comprising a step of adjusting a luminous intensity of the light emission (104) using the light emission value. [10] Method according to one of the preceding claims, comprising at least one further step of reading (401) a further distance value representing a distance between the vehicle (100) and a further object (110) located in the vicinity of the vehicle (100), at least one further step of reading (403) a further irradiance value representing a height of an area of ​​the further object (110) illuminated by the light emission (104), and at least one further step of determining (405) a further light emission value characterizing the light emission (104) using the further distance value and the further irradiance value. [11] Method according to claim 10, comprising a step of filtering and / or mediating the light emission values ​​to determine a light emission value based on at least two light emission values. [12] Device (102) for analyzing a light emission (104) of a headlight (106) of a vehicle (100), wherein the device has the following features: a reading device (112) for reading a distance value representing a distance between the vehicle (100) and an object (110) located in the vicinity of the vehicle (100); a reading device (114) for reading an irradiance value representing the height of an area of ​​the object (110) illuminated by the light emission (104); and a determining device (116) for determining a luminous emission value characterizing the luminous emission (104) using the distance value and the irradiance value characterized by an object recognition device (126) which is configured to determine the irradiation value based on video-based object recognition and a predetermined dimension of the object (110) assigned to the object (110). [13] Computer program configured to perform all steps of a method according to claim 1. [14] Machine-readable storage medium with a computer program stored thereon according to claim 13.

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