Methods for projecting light distributions and light distribution systems

Abstract

Method for projecting light distributions (10) for a vehicle (12, 12a) using a light distribution system (14), wherein the light distribution system (14) comprises at least one sensor unit (16) for determining position data (18) of the vehicle (12, 12a), a computing unit (20), and at least one light projector (22), wherein the computing unit (20) converts target light distributions (24) stored in the computing unit (20) into projection data (26) related to the light projector (22), and the light projector (22) uses the projection data (26) to project the light distributions (10) onto at least one projection surface (32) in the environment, wherein the position data (18) of the vehicle (12, 12a) determined by the at least one sensor unit (16) are12a) are transmitted to a correction calculation module (28) of the computing unit (20), and the correction calculation module (28) uses the position data (18) to calculate corrected projection data (30) from the projection data (26), and the corrected projection data (30) are forwarded to the light projector (22) for the projection of corrected light distributions (10), characterized in that several sensor units (16), comprising inertial sensors and a camera system, are combined with the vehicle data, such as speed and steering angle, to further increase the accuracy of the correction by skillfully predicting the possible vehicle movements determined as position data (18), wherein the inertial sensors are acceleration sensors and yaw rate sensors which determine the vehicle movements as position data (18), wherein the sensor units (16) transmit position data (18) of the vehicle (12,12a) provide for use in the correction calculation module (28), wherein the vehicle movements are calculated as position data (18) in the correction calculation module (28) using algorithms based on the data determined by the camera system, wherein the projection data (26) are calculated by the computing unit (20) in parallel with the determination of the projection data (30) corrected by the correction calculation module (28), based on the specified target light distribution (24) and the position of the projection surface (32) detected by the light distribution system (14), wherein the corrected projection data (30) are recalculated every 10 to 40 milliseconds, and the correction calculation module (28) always refers back to the most recently determined projection data (26), whereby irregularities of the projection surface (32) are taken into account and thus a pre-distortion is implemented in the projection data (26) and in the corrected projection data (30).

Description

[0001] The invention relates to an improved method for projecting light distributions using a vehicle's light distribution system, including light distributions that represent graphics. The invention further relates to the associated light distribution system.

[0002] Light distribution systems are known in various designs.

[0003] German patent DE 10 2014 000 495 A1 discloses an electronic device with a display in which at least one pixel acts as a transmitter. This pixel modulates its light intensity synchronously with a transmitted signal and feeds this light into a first transmission path. The light is reflected or transmitted by an object to be measured and reaches a receiver via a second transmission path as an optical object signal. Additionally, there is a compensation transmitter that sends a compensation light signal to the receiver via a third path. In the receiver, both signals are superimposed and converted into an output signal. A controller adjusts the amplitudes of the transmitted signals so that certain signal components disappear in the output signal. The pixels of the display can be used as transmitters for various sensor functions, such as distance sensors, air quality sensors, color sensors, surface classification, or gesture recognition systems.

[0004] German patent application DE 10 2018 218 038 A1 discloses a system for projecting informative content onto a motor vehicle. The system comprises environmental sensors, a control unit, and at least one projection device for projecting the content. The environmental sensors are configured to detect the position of a projection surface in the vicinity of the motor vehicle. The control unit is configured to receive content to be projected and, based on the detected position of the projection surface, to adjust it so that, when projected onto the projection surface, it can be perceived in perspectively correct form from the perspective of a predetermined viewer. According to the invention, the at least one projection device is a high-resolution headlight.

[0005] A lighting device for a vehicle is known from publication WO 2018 / 215 609 A1. The lighting device comprises at least one headlight, a position and / or acceleration sensor, and a control unit coupled to this position and / or acceleration sensor for adjusting a light-dark boundary of the headlight. The position and / or acceleration sensor detects pitching movements of the vehicle, and the control unit compensates for changes in the light-dark boundary caused by these pitching movements. According to the invention, the position and / or acceleration sensor and the control unit are arranged in the headlight.

[0006] The invention, based on the prior art, aims to provide a light distribution system that enables faster adaptation of the projected light distribution to changing positions of the vehicle, particularly due to translational and rotational movements such as pitching and yaw. During vehicle movement, translational movements and various rotational movements, such as pitching, yaw, and roll, are superimposed. In particular, the deviation of the actual light distribution achieved by the light projectors from the desired light distribution should be significantly reduced.

[0007] The problem is solved by a method according to claim 1 and by a device according to claim 5.

[0008] Light distribution, as used here, refers to the manner in which light is distributed onto a projection surface. Specifically, light distribution is the distribution of headlight beams to effectively illuminate the roadway, for example, to prevent glare for oncoming traffic. This also includes the distribution of light in varying brightness and color to display graphics, particularly symbolic representations (such as guide lines, arrows, crosswalks, and other symbols) on the roadway or other projection surfaces. The target light distribution is the desired light distribution stored in the light distribution system in a suitable data format. The target light distribution can vary depending on the road layout and traffic conditions. For this purpose, a data connection with the vehicle's navigation system is useful.

[0009] The invention relates to a method for projecting light distributions using a vehicle's light distribution system, and to the associated light distribution system. The light distribution system comprises a sensor unit for determining position data regarding changes in the vehicle's position and orientation in space, a processing unit, and at least one light projector.

[0010] The vehicle's altered position, particularly due to rotations (yaw during cornering), pitching and rolling movements, as well as straight-line driving, lateral movements, and heaving movements, which can overlap, are collectively referred to as position information, which is determined by the sensor unit as position data. This position information comprises translational deviations in the x, y, and z directions and angular deviations with respect to the longitudinal axis (x-axis), the transverse axis (y-axis), and / or the vertical axis (z-axis), as detected by the sensor unit.

[0011] The processing unit converts the target light distributions stored in the unit into projection data related to the light projector. This typically involves determining the position of the projection surface relative to the vehicle and taking this into account when calculating the projection data.

[0012] Using a light projector, the desired light distributions are projected from projector-compatible projection data onto a projection surface in the surrounding area, preferably the roadway in front of the vehicle. If necessary, a projection can also be made beside or behind the vehicle. The light distributions can be either graphics to be projected or simple light distributions (light cones) for the appropriate illumination of the roadway and its surroundings.

[0013] The inventive problem is solved by creating a method for projecting light distributions for a vehicle's light distribution system.

[0014] According to the invention, the vehicle's position data determined by the sensor unit is transmitted to a correction calculation module of the processing unit. Using the position data, the correction calculation module calculates corrected projection data from the projection data for projecting the light distributions onto a projection surface (for example, the roadway) in the vicinity of the vehicle. The corrected projection data is then forwarded to the light projector, preferably a headlight, for projecting the corresponding light distribution into the surroundings. The correction calculation module can be integrated into the processing unit at the hardware level.

[0015] The inventive concept consists of using the correction calculation module to provide projection data for the light projector with a higher repetition frequency, corrected for changes in the vehicle's position. This solution advantageously enables faster dynamic adjustment of the light distributions in response to changes in the vehicle's position. Consequently, the light distributions can be projected with less latency and thus more precisely. This significantly reduces the deviation of the actual light distribution projected by the light projectors from the target light distribution.

[0016] The deviations in the x, y, and z directions, or angular deviations due to rotation along the x, y, and z axes, determined from the positional information, are used as displacements and / or angular deviations to correct the projection data and, consequently, to calculate the corrected projection data. Correcting the projection data calculated by the processing unit can therefore be performed significantly faster than completely recalculating the projection data, including the correction. This allows for a very high repetition frequency for adjusting the projection of the light distributions to the vehicle's changing positional information. This results in improved projections of the light distribution onto the projection surface and thus considerably reduces erroneous deviations from the target light distribution.The solution found advantageously avoids, among other things, double images when projecting light distributions.

[0017] The corrected projection data can be determined from the projection data with significantly less computational effort and therefore in a shorter time than a complete recalculation of the projection data.

[0018] Further preferred embodiments of the invention result from the other features mentioned in the dependent claims.

[0019] In a preferred embodiment of the invention, the corrected projection data is determined within 10–40 milliseconds, preferably within 20 milliseconds. Accordingly, the light distribution repetition frequency can be advantageously adapted very quickly to the changing position of the vehicle.

[0020] In a further preferred embodiment of the method according to the invention, it is provided that the projection data, based on the specified target light distributions and a projection area detected by the light distribution system, are calculated by the computing unit in parallel with the determination of the corrected projection data.

[0021] The correction calculation module uses the most recently determined projection data to calculate the corrected projection data. The target light distribution is stored in the light distribution system, preferably in the processing unit. It can also be transferred to the light distribution system via a connection to the navigation system or using common storage media. Simultaneously, the projection surface, such as the roadway, is captured by a camera system.

[0022] With appropriate training, the sensor unit can also be used to determine the position of the projection surface. The projection data is determined by converting the target light distribution onto the projection surface, taking into account the vehicle's position relative to the surface. This solution is already known. However, the computational effort required to fully calculate the projection data is greater than that required to correct it. Consequently, the calculation time is longer, leading to delays and thus errors in the projection. By calculating the projection data in parallel with the corrected projection data, the latter can be updated at longer intervals.

[0023] This projection data can then be used in shorter cycles to determine the corrected projection data. For example, the projection data can be recalculated within five correction cycles. Correcting the projection data in shorter cycles is necessary because the vehicle's position and orientation can change very quickly. In contrast, the projection surface onto which the light distributions are projected changes to a much lesser extent, so recalculation in longer cycles without any loss of quality is unproblematic.

[0024] In a further preferred embodiment, the projection data and the corrected projection data for two or more light projectors are calculated separately, taking their characteristics into account. In particular, the different positioning of the headlights on the vehicle is considered. Typically, the road is illuminated by two headlights. The light projectors are controlled separately for each headlight using the corrected projection data in order to achieve a uniform light distribution on the road. This prevents double images. In addition to the headlights, an additional light projector can be advantageously used, for example, to project signs onto the road.

[0025] In a further preferred embodiment, unevenness of the projection surface is taken into account, and a pre-distortion is accordingly implemented in the projection data and in the corrected projection data. By adjusting with respect to the pre-distortion, the projected light distribution can be advantageously dynamically adapted to unevenness of the projection surface due to changes in the vehicle's position.

[0026] In a further preferred embodiment, the desired light distributions are two-dimensional or 3D-animated (i.e., spatially structured) light distributions, presented as a cropped image, a 360° panorama, or a spherical panorama. The inventive method, which enables dynamic adjustment of the light distribution, is thus advantageously suited to various requirements.

[0027] The inventive problem is further solved by an inventive light distribution system with preferred embodiments of the sensor unit.

[0028] The sensor unit of the light distribution system is designed as an inertial measurement unit. An inertial measurement unit consists of several inertial sensors, such as accelerometers and gyroscopes, which together form an inertial navigation system.

[0029] Alternatively, an optical camera system, such as a time-of-flight camera, a stereo camera, a dynamic vision sensor, or a neuromorphic sensor, can be used as the sensor unit. The vehicle movements can then be calculated advantageously from the data acquired by the optical camera system using algorithms in the correction calculation module.

[0030] In another version, the sensor unit is designed as a projector-camera system that generates a dynamic 3D model of the environment using pattern projection. The vehicle's relative position and thus its own motion can be derived from this dynamic 3D model.

[0031] Thus, the different sensors can provide the position data for use in the correction calculation module in an advantageously suitable manner.

[0032] Furthermore, multiple sensor units, such as inertial sensors and camera systems, can be combined with vehicle data, such as speed and steering angle, to further increase the accuracy of the correction by cleverly predicting possible vehicle movements.

[0033] In a further preferred embodiment of the invention, the light projector is a high-resolution digital light or projection system and / or a headlight with an LED pixel matrix.

[0034] The aforementioned advantageous designs of the light projector enable the projection of a light distribution, especially a graphic light distribution, in advantageously high quality.

[0035] Unless otherwise stated in individual cases, the various embodiments of the invention mentioned in this application can be advantageously combined with one another.

[0036] The invention is explained below using exemplary embodiments with reference to the accompanying drawings. These show: Fig. 1. A block diagram of the method for projecting light distributions, Fig. 2a a vehicle on a level roadway, Fig. 2b a vehicle at a crest with unsuitable light distribution, Fig. 2c a vehicle at a crest with adapted light distribution, Fig. 3a a swaying vehicle in two consecutive depictions, Fig. 3b the light distributions of a swaying vehicle, Fig. 4. A 3D graphic projected onto the roadway.

[0037] The Fig. Figure 1 shows a block diagram of the method for projecting light distributions 10 for a vehicle. The projection of the light distributions 10 is realized by a light distribution system 14. The light distribution system 14 comprises a sensor unit 16 for determining position data 18 and projection surface data 34 of the vehicle (not shown), a processing unit 20, and at least one light projector 22.

[0038] The target light distributions 24 are stored in the processing unit 20. These are converted in the processing unit 20 into projection data 26 related to the projection surface 32 and the light projector 22. The light projector 22 is, for example, a headlight 22 with an LED pixel matrix. To determine the projection data 26, the projection surface 32 located in the vicinity of the vehicle is detected by the sensor unit 16, for example, a camera system. The determined projection surface data 34 are transmitted to the processing unit 20.

[0039] These determined projection data 26 are suitable for controlling the light projector 22 so that it projects light distributions 10 onto the projection surface 32 that correspond to the target light distributions 24. According to the invention, a correction calculation module 28 is provided between the processing unit 20 and the light projector 22.

[0040] The correction calculation module 28 converts the received projection data 26 into corrected projection data 30 using the position data 18 determined by the sensor unit 16 with respect to the vehicle. Using this corrected projection data, the light projector 22 projects corrected light distributions 10 onto the projection surface 32.

[0041] The position data 18 determined by the sensor unit 16 relate to the change in the vehicle position with respect to rotation about the x, y, and z axes or the displacement of the vehicle 12, 12a in the direction of the x, y, and z axes (see Fig. 2a, Fig. 2b, Fig. 3a).

[0042] This allows, for example, the pitching and rolling movements of the vehicle 12, 12a to be detected. An advantage of the invention is that it is significantly faster, and therefore with considerably less delay / latency, to determine corrected projection data 30 from the projection data 26 than to recalculate the projection data 26 each time. Thus, shorter cycles for updating the corrected projection data 30 can be advantageously implemented.

[0043] Due to the significantly reduced latency, the projected light distributions 10 correspond much better to the desired target light distributions 24. In addition, the computing power can be reduced, which advantageously lowers the costs of the light distribution system 14.

[0044] Parallel to the calculation of the corrected projection data 30 in the correction calculation module 28, the calculation of the projection data 26 takes place in the computing unit 20. Thus, the corrected projection data 30 can be determined from the correction calculation module 28 based on the latest projection data 26.

[0045] In Fig. Figure 2a shows a vehicle 12 on a level roadway 32 in a side view. The roadway 32 here also serves as the projection surface 32 for the light distribution 10 projected by the headlight 22. The vehicle 12, traveling on the level roadway 32, projects a light distribution 10, shaped as a headlight cone 10, onto the roadway 32 with its headlight 22. Fig. 2b shows the same vehicle 12a at a crest 36 with the light distribution 10a not yet adjusted. When approaching the crest 36 ( Fig. 2b) A change in the orientation of vehicle 12a occurs, which is indicated by the pitch angle α of vehicle 12a. The pitch angle α indicates the change in the orientation of vehicle 12, 12a due to deviation from the x-axis. Thus, here the pitch angle α is the deviation of the x-axis at time . Fig. 2a to the xa-axis at time in Fig. 2b.

[0046] The change in the orientation of the vehicle 12, 12a results in a change in the light distribution 10a with respect to the roadway 32. The headlight cone 10a now extends further, potentially dazzling oncoming traffic. Based on the pitch angle α detected by the sensor unit (not shown) using the inventive method, the corrected projection data 30 in the correction calculation module 28 are adjusted so that the corrected light cone 10a is Fig. 2c again the one in Fig. The target light distribution shown in 2a corresponds to 24.

[0047] The Fig. Figure 3a shows a swaying vehicle 12, 12a in two consecutive representations.

[0048] In Fig. 3b are the corresponding light distributions 10, 10a of the in Fig. 3a shows the swaying vehicle 12, 12a.

[0049] Vehicle 12, as shown in the background, is oriented differently than vehicle 12a, which will be visible in the foreground at a later time. The change in orientation is indicated by the altered z-axis and za-axis, respectively.

[0050] The angle β between the z-axis and the za-axis is the roll angle β. Without the solution according to the invention, the roll of the vehicle 12a with respect to the initial orientation of the vehicle 12 leads to the light distribution 10a deviating from the target light distribution 24, 10 (hatched).

[0051] The roll angle β as a change in the orientation of the vehicle 12, 12a is detected by the sensor unit (not shown) according to the solution according to the invention.

[0052] Accordingly, the correction calculation module (not shown) calculates the corrected projection data 30 at short intervals and forwards it to the headlight 22. This allows the light distributions 10 to be advantageously adapted to the changing position information of the vehicle 12, 12a with short latency and low computational effort. Consequently, the light distribution system 14 can react very quickly to changes in the position of the vehicle 12, 12a – for example, within 20 milliseconds (see arrows) – and project a light distribution 10 that corresponds to the target light distribution 24.

[0053] The Fig.Figure 4 shows a light distribution 10 projected onto the roadway 32, which is represented here as a 3D graphic 10. The sensor unit (not shown) detects not only changes in angle with respect to the x, y, and z axes but also displacements along these axes. Using the correction calculation module (not shown), the projector can then fix the zebra-stripe light distribution 10 onto the roadway. Reference symbol list 10 Light distribution, light cone, 3D graphics 10a Different light distribution, different light cone 12, 12a Vehicle 14 Light distribution system 16 sensor units 18 Location data, location information in x, y and z directions 20 computing units 22 Light projector, headlight, vehicle headlight 24 Target light distribution 26 projection data 28 Correction Calculation Module 30 corrected projection data 32 Projection area, roadway 34 Projection surface data x, x a x-direction, x-axis y y-direction, y-axis z, z a z-direction, z-axis α Angular deviation to the x-axis, pitch angle β Angular deviation in the z-axis, roll angle

Claims

[1] Method for projecting light distributions (10) for a vehicle (12, 12a) using a light distribution system (14), wherein the light distribution system (14) comprises at least one sensor unit (16) for determining position data (18) of the vehicle (12, 12a), a computing unit (20) and at least one light projector (22), wherein the computing unit (20) converts target light distributions (24) stored in the computing unit (20) into projection data (26) related to the light projector (22) and the light projector (22) uses the projection data (26) to project the light distributions (10) onto at least one projection surface (32) in the environment, wherein the position data (18) of the vehicle (12, 12a) determined by the at least one sensor unit (16) are12a) are transmitted to a correction calculation module (28) of the computing unit (20) and the correction calculation module (28) calculates corrected projection data (30) from the projection data (26) using the position data (18) and forwards the corrected projection data (30) to the light projector (22) for the projection of corrected light distributions (10), , characterized bythat several sensor units (16), comprising inertial sensors and a camera system, are combined with vehicle data, such as speed and steering angle, to further increase the accuracy of the correction by skillfully predicting the possible vehicle movements determined as position data (18), wherein the inertial sensors are acceleration sensors and yaw rate sensors which determine the vehicle movements as position data (18), wherein the sensor units (16) provide the correction calculation module (28) with position data (18) of the vehicle (12, 12a) for use in the correction calculation module (28), wherein the vehicle movements are calculated as position data (18) from the data determined by the camera system in the correction calculation module (28) using algorithms,wherein the projection data (26) are calculated by the processing unit (20) in parallel with the determination of the projection data (30) corrected by the correction calculation module (28), based on the specified target light distribution (24) and the position of the projection surface (32) detected by the light distribution system (14), wherein the corrected projection data (30) are recalculated every 10 to 40 milliseconds, and the correction calculation module (28) always refers back to the most recently determined projection data (26), whereby unevenness of the projection surface (32) is taken into account and thus a pre-distortion is implemented in the projection data (26) and in the corrected projection data (30). [2] Method for projecting light distributions (10) according to claim 1, characterized by , that the corrected projection data (30) are recalculated within 20 milliseconds each time. [3] Method for projecting light distributions (10) according to claim 1, characterized by , that the projection data (26) and the corrected projection data (30) for two or more light projectors (22) are calculated separately, taking into account their positioning on the vehicle (12, 12a). [4] Method for projecting light distributions (10) according to claim 1, characterized by , that the desired light distributions (24) are two-dimensional light distributions or 3-D animated light distributions, wherein the desired light distributions (24) are available as a format section, as a 360° panorama or as a spherical panorama. [5] Light distribution system (14) for projecting light distributions (10) for carrying out the method according to any one of claims 1 to 4, comprising, a computing unit (20) and at least one light projector (22), and a correction calculation module (28) which transmits the position data (18) of the vehicle (12, 12a) determined by the at least one sensor unit (16) to a correction calculation module (28) of the computing unit (20), wherein the correction calculation module (28) uses the position data (18) to calculate corrected projection data (30) from the projection data (26) and forwards the corrected projection data (30) to the light projector (22) for the projection of corrected light distributions (10), characterized by , that Several sensor units 16, comprising inertial sensors and a camera system, are arranged, wherein the inertial sensors are accelerometers and gyroscopes which determine the vehicle movements as position data (18), wherein the sensor units (16) provide position data (18) of the vehicle (12, 12a) to the correction calculation module (28) for use in the correction calculation module (28), wherein the vehicle movements are calculated as position data (18) from the data determined by the camera system in the correction calculation module (28) by means of algorithms, wherein the camera system is a time-of-flight camera or a stereo camera, or a dynamic vision sensor or a neuromorphic sensor or a projector camera system. [6] Light distribution system (14) according to claim 5, characterized by , that the light projector (22) is a high-resolution digital projection system. [7] Light distribution system (14) according to claim 5, characterized by, that the light projector (22) is a spotlight (22) with an LED pixel matrix. [8] Light distribution system (14) according to claim 5, characterized by , that the projector-camera system generates a dynamic 3D model of the environment using pattern projection.

Images