WO2023174621A1

WO2023174621A1 - Projection system for a test stand for driver assistance systems of a motor vehicle

Info

Publication number: WO2023174621A1
Application number: PCT/EP2023/053214
Authority: WO
Inventors: Martin Heller; Klaus Allen
Original assignee: Bayerische Motoren Werke Aktiengesellschaft
Priority date: 2022-03-16
Filing date: 2023-02-09
Publication date: 2023-09-21
Also published as: DE102022106205A1

Abstract

A projection system for a test stand for driver assistance systems of a motor vehicle is provided, having at least one projection device which is arranged and designed to project an image onto a base of the test stand, a camera which is designed to capture, in the form of image data, the image projected onto the base of the test stand, and a control unit designed to determine an actual position of the image projected onto the base on the basis of the image data acquired by the camera, and, on the basis of the determined actual position and a target position of the image projected onto the base, to align the projection device such that the actual position and the target position correspond.

Description

PROJECTION SYSTEM FOR A TEST BENCH FOR DRIVING ASSISTANCE SYSTEMS OF A MOTOR VEHICLE

The present invention relates to a projection system for a test bench for driving assistance systems of a motor vehicle, a test bench with the projection system and the use of the projection system on such a test bench.

Projection systems are known from the prior art, which project road courses onto projection surfaces in order to test driving assistance systems, such as camera-guided road and/or person recognition. The projection takes place on screens or hollow spheres in a closed room. Laser-based measurement of the images in order to synchronize them from different projectors is also state of the art.

According to US 2019/204427 A1, a device for calibrating sensors of an autonomous vehicle includes a camera calibration target that is configured to be measured by an optical camera of the vehicle and used for calibration; a light detection and ranging calibration target (LiDAR) configured to be measured by a vehicle LiDAR transceiver and used for calibration; and a platform configured to allow the vehicle to drive onto and park on the platform. The camera calibration target and the LiDAR calibration target are positioned so that they can be captured by the optical camera and the LiDAR transceiver while the vehicle is parked on the platform. The platform is further configured to change a lateral position, elevation, or orientation of the optical camera and the LiDAR transceiver relative to the camera calibration target and the LiDAR calibration target while the vehicle is parked on the platform.

US 2008/186384 A1 describes a camera calibration device with a parameter determiner which is suitable for determining parameters for the projection of an image recorded with a camera onto a predetermined surface. The parameter determiner determines the parameters based on a calibrating image from the camera, and the image to be calibrated contains a plurality of calibration patterns with previously known shapes arranged at various positions within the recording area of the camera.

In addition, to secure parking maneuvers or for homologation by technical services, road markings are traditionally stuck to ground surfaces, recorded and measured according to the test plan. Basically, such a measurement is time-consuming, causes high costs, is inflexible and prone to errors.

Against the background of this prior art, the object of the present invention is to provide a device and a method which are each suitable for overcoming at least the above-mentioned disadvantages of the prior art.

The task is solved by the features of the independent claim. The subclaims have preferred further training as their content.

The task is then solved by a projection system for a test bench for driving assistance systems of a motor vehicle.

This means that a projection system is provided that is structurally suitable for use on a motor vehicle test bench.

Using the projection system, driving assistance systems, in particular their reliability and/or accuracy, can be tested on the test bench. The driving assistance system can represent an additional electronic device in the motor vehicle to be tested to support the driver in certain driving situations. The functionality and in particular the range of functions of the driving assistance system can depend on the degree of automation of the motor vehicle. It is conceivable that the driving assistance system can at least partially and/or temporarily take over transverse and/or longitudinal guidance of the motor vehicle. The driving assistance system can, for example, have an ultrasonic sensor Have a camera, a radar sensor and / or a LiDAR sensor. These sensors can be checked for functionality by means of the projection system, in particular by the test environment generated by the projection system. The motor vehicle can be an automobile.

The projection system has at least one projection device which is arranged and designed to project an image onto a surface of the test bench.

The image can be understood as a projection, which can also be referred to as an image projection. A projection can be understood as an enlarged (or reduced or otherwise modified) transfer of an image onto a projection surface, here the subsurface or floor.

The projection system has a camera that is designed to capture the image projected onto the surface of the test bench in the form of image data.

This means that the camera can have a field-of-view (FOV) that covers, in particular completely, the area in which the image is projected onto the ground. This area can also be referred to as the test area. If an image is taken with the camera, the image projected onto the surface using the projection device can automatically be seen in the image.

The projection system has a control unit that is designed to determine an actual position of the image projected onto the background based on the image data captured by the camera. The control unit is further designed to align the projection device based on the determined actual position and a target position of the image projected onto the background so that the actual position and the target position match.

In other words, the control unit is connected to the camera on the input side and receives the image recorded by the camera. Based on this, the control unit recognizes, for example using an object recognition algorithm that receives the image data recorded by the camera as input data, where the image is located underground. This corresponds to the actual position. If the actual position deviates from the target position, the control unit outputs a control signal to the projection device and changes its orientation in order to shift the actual position of the image projected onto the surface towards the target position. This can be repeated until the target position and the actual position match.

The system can be used to project road markings, parking lot markings and positions of test obstacles (so-called targets) onto the test area. The projection system described above therefore allows a changeable test environment to be automatically projected onto a test stand, i.e. there is no need for time-consuming manual construction and modification of the test environment. In addition, the system can be designed to be portable, i.e. it can be used regardless of location. This means that stationary, highly flexible scenarios can be displayed and created, which can be used quickly and easily at any time for the homologation of driving assistance systems, such as parking assistance systems. These can therefore be applied worldwide in a standardized or modifiable manner or can be used by technical services for the homologation of all vehicles through standardized, quickly transferable and modifiable scenarios to help position road markings, parking lot markings and obstacles.

Preferred developments of the projection system described above are described in detail below.

The projection device can have at least two projectors arranged at a distance from one another, which are arranged and designed to each project at least part of the image onto the background of the test bench. The actual position determined by the control unit can include a respective actual position of both parts of the image, and the target position used by the control unit can include a respective target position of both parts of the image.

The use of several projectors that project the image or part of it onto the surface from different angles offers the advantage that a Shadows cast by objects on the surface can be avoided. This is particularly advantageous if four projectors are used, which are arranged, for example, at the same distance from one another. Each part of the image can be assigned its own target position, so that the partial images complement each other to form an entire image as soon as the respective target position is reached.

The image may have multiple markers arranged at a predetermined distance from one another. The markings can be, for example, a position marking for an obstacle to be positioned at the position marking, a line and/or a road marking.

This means that the image projected onto the surface itself can contain information that is to be recognized by the driving assistance system being tested, such as the road markings. In addition, physical obstacles (e.g. pylons or a dummy curb) can also be placed on the lines and/or position markings that are to be recognized by the driving assistance system. In particular, this means that manual measurement of positions can be avoided and the projection can be used more or less as a changeable template.

The control unit can be designed to use a hardware control signal to change an orientation and/or position of the projection device so that the actual position and the target position match.

This means that the control unit can, for example, use a servomotor to change a distance of the projection device and/or an angular position of the projection device to the background in order to bring the actual position into line with the target position of the image. The subsurface can be horizontal.

The control unit can be designed to use a software control signal to change the image projected onto the surface by the projection device so that the actual position and the target position match. In other words, in addition or alternatively, in addition to the hardware control signal, a software control signal can also be output to the projection device. The software control signal may contain image data corresponding to the image to be displayed on the background by the projection device. This means that the image projected onto the surface by the projection device itself can be changed so that the actual position and the target position match.

The projection system can have target position markers that can be attached to the surface of the test stand. The camera can be designed to capture the target position markers in the form of the image data, and the control unit can be designed to detect the target position of the image projected onto the ground based on the target position markers contained in the image data to determine.

It is conceivable, for example, that markings are attached to the surface and certain parts of the image projected onto the surface are to be arranged within the marking so that the target position and the actual position match. It is also conceivable that the projectors themselves project markings onto the floor, which are arranged in overlapping image areas of the individual projectors and which should be made to coincide so that the target position and the actual position match.

The camera can be designed to capture a motor vehicle located on the surface of the test bench in the form of image data. The control unit can be designed to determine the target position of the image projected onto the ground based on the motor vehicle contained in the image data.

This means that the motor vehicle and its position can be recognized and the control device can be designed to adapt the test environment to be generated by means of the projection to the actual position of the motor vehicle.

The camera may be connected to a storage device designed to store the image data captured by the camera. The projection system thus allows both the test environment and, if necessary, the execution of the test to be documented, which is particularly advantageous for homologations.

Furthermore, a test bench for driver assistance systems of a motor vehicle is provided, comprising the projection system described above and a support system which is adjustable in height by the control unit and to which the projection system is at least partially attached. What was described above with reference to the projection system also applies to the test bench and vice versa.

Furthermore, the disclosure relates to a use of the projection system described above on a test bench for driver assistance systems of a motor vehicle. What has been described above with reference to the projection system and test bench also applies analogously to the use of the projection system on such a test bench and vice versa.

In other words and with reference to a more specific embodiment, what has been described above can be summarized as described below, which only includes a description of optional features and does not limit the disclosure.

The disclosure is based on the principle of arranging (image) projectors on ceiling supports of a covered area. To implement the disclosure, it was found that projectors can be attached to a lowerable frame, as is common in the lighting area of trade fairs, for example. These frames can be lowered and can be fixed to the hall ceiling in a covered hall at a changeable but essentially precisely adjustable height. These projectors are aligned using the control unit in such a way that the images generated are synchronized through the use of several projectors. The projected test images of the system can be measured by a control computer and adjusted using lasers or synchronization points. Using multiple synchronized projectors creates shadows prevented. The arrangement can, for example, have at least four projectors. This is useful in order to exclude the formation of shadows. The control computer can be used to project road markings or positions of obstacles onto the hall floor. Obstacles for, for example, Parking Distance Control (PDC) and/or radar detection of the subject's driving assistance systems to be homologated can therefore be precisely positioned and set up. This means that these projectors depict positions, lines and road markings on the road surface below. Obstacles can now be located at appropriate markings in a precisely reproducible and positionable manner. The road markings are also displayed and can be depicted or positioned and made visible with adhesive applications and/or linoleum coverings. The vehicle's PDC sensors can detect these obstacles and camera-guided systems can also recognize and interpret the markings on the road. This means that homologation of such functions can be carried out quickly and reproducibly. Further scenarios can be displayed by the control computer and quickly implemented on the ground. Optionally, the positioning of the targets can be recorded using a camera system that can also be provided and recorded and documented for audit-proof proof of homologation. The system can be portable and multipliable and can therefore be used worldwide. Changes in laws and processes can be quickly distributed and reproducibly rolled out through software updates.

An embodiment is described below with reference to Figures 1 to 3.

1 shows schematically a test stand for driving assistance systems of a motor vehicle with a projection system according to the disclosure,

Fig. 2 shows schematically a projection surface of the test stand from Figure 1, and

Fig. 3 shows schematically a test stand for driving assistance systems of a motor vehicle with two projection systems according to the disclosure. In the following description of the figures, the same reference numbers are used for the same objects in the figures.

In Figure 1, a test bench 1 for driver assistance systems of a motor vehicle 11, which is shown only schematically in Figure 1, is shown in a perspective view.

The test stand is installed in a test hall 2 indicated in FIG. 1, which represents a closed room.

The test stand 1 has a projection system 3, which is partially installed on the ceiling of the test hall 2, as well as a support system 5, which can be adjusted in height by a control unit 4 and a ceiling drive 6, to which the projection system 3 is partially attached.

The projection system 3 includes a projection device 7 with four projectors 8, each of which is arranged and designed to project a part of an image onto a background or a projection surface 9 of the test stand 1. In the present case, the four projectors 8 are each arranged at a corner of a square frame of the support system 5.

Furthermore, the projection system 3 has a camera 10, which is designed to capture the image projected onto the surface 9 of the test bench 1 in the form of image data.

Furthermore, the projection system 3 has the control unit 4, which is connected to both the camera 10 and the projection device 7, in particular the individual projectors 8.

The control unit 4 is designed to receive and process the image data captured by the camera 10. First, the control unit 4 determines a target position of the image projected onto the background 9 based on the image data received from the camera 10. For this purpose, the control unit 4 uses target position markers 91 (in the present case cross-shaped) contained in the image data, which in the present case are fixed are applied to the surface 9 designed as a linoleum carpet, which is shown in detail in Figure 2. The camera 10 is therefore positioned and designed to capture the target position markers 91 in the form of the image data. It would also be conceivable that the camera 10 is designed to capture the motor vehicle 11 located in the area of the subsurface 9 of the test bench 1 in the form of image data, so that the control unit 4 additionally or alternatively detects the target position of the image projected onto the subsurface 9 based on the motor vehicle 11 contained in the image data.

The control unit 4 then determines, based on the image data, an actual position of the image projected onto the background 9 using (in this case cross-shaped) actual position markers 92, which are each projected onto the background 9 by the individual projectors 8. Since four projectors 8 are used in the present case, the control unit 4 determines an actual position of the respective part of the image that the respective projector 8 points to based on the actual position marker(s) 92 displayed by the respective projector 8 Projected underground.

Based on the determined actual position and the target position of the image projected onto the surface 9, the control device 4 determines a control signal and outputs this to the projection device 7, in particular to the individual projectors 8, and possibly also to the ceiling drive 6, in order to align the projection device 7, in particular its individual projectors 8, so that the actual position and the target position match. This is the case, as shown in Figure 1, when the target position markers 91 and the actual position markers 92 match. Since the target position markers 91 include a respective target position of the four parts of the image, correct alignment of the individual parts of the image is automatically achieved. The control unit 4 is designed to use a hardware control signal to change an orientation of the projection device 7 in space and/or a position of the projection device 7 so that the actual position and the target position match. In addition, the control unit 4 is designed to use a software control signal to control the image projected by the projection device 7 onto the surface 9. in particular the individual parts of the image, to change so that the actual position and the target position match.

If the target position and the actual position match, a predetermined test scenario, i.e. a predetermined image, is projected onto the surface 9 under the control of the control unit 4 using the projection device 7, i.e. the individual projectors 8. This image is true to scale, i.e. the distances between individual markings 12 contained in the image, which are used for test purposes, correspond to, for example, legal requirements and form a coherent or synchronized scenario. The image can therefore have several markings 12, which, for example, have a position marking 13 for an obstacle 14 to be positioned at the position marking 13 (see also FIG. 2), lines 15, road markings 16 and/or other markings 17 which are at a predetermined distance are arranged to each other. This can be documented using the camera 10, whose recorded image data is stored in a storage device (not shown) connected to the camera 10 (which is, for example, part of the control unit 4). The same applies to the documentation of the test using the camera 10. A monitor (not shown) can be connected to the control unit 4 so that a user of the test stand 1 can monitor and/or control the test.

It is also conceivable that the image/scenario projected onto the surface 9 described above is supplemented by markings 12 that have already been applied to the surface, as is illustrated by way of example in FIG. 2 using the road marking 18.

In addition, the disclosure is not limited to the use of a single projection system 3, but rather several projection systems 3 can be provided, as shown in a side view in FIG. In this case, the images of the respective projection systems 3 projected onto the surface 9 can overlap (as shown in FIG. 3), so that the projection systems 3 can be aligned with one another in the manner described above. Reference symbol list

1 test bench

2 test hall

3 projection system

4 control unit

5 carrier system

6 ceiling drive

7 projection device

8 projector

9 projection surface

91 target position markers

92 actual position markers

10 camera

11 motor vehicle

12 markers

13 position markers

14 obstacles

15 lines

16 road markings

17 additional markings (e.g. parking lot markings)

18 marking applied to the surface

Claims

Patent claims

1 . Projection system (3) for a test bench (1) for driving assistance systems of a motor vehicle (11), comprising:

- at least one projection device (7) which is arranged and designed to project an image onto a surface (9) of the test bench (1),

- a camera (10) which is designed to capture the image projected onto the surface (9) of the test stand (1) in the form of image data, and

- a control unit (4) which is designed to:

- to determine an actual position of the image projected onto the surface (9) based on the image data captured by the camera (10), and

- based on the determined actual position and a target position of the image projected onto the surface (9), align the projection device (7) so that the actual position and the target position match.

2. Projection system (3) according to claim 1, wherein:

- the projection device (7) has at least two projectors (8) arranged at a distance from one another, which are arranged and designed to each project at least part of the image onto the surface (9) of the test bench (1),

- the actual position determined by the control unit (4) includes a respective actual position of both parts of the image, and

- The target position used by the control unit (4) includes a respective target position of both parts of the image.

3. Projection system (3) according to claim 1 or 2, wherein the image has several markings (12), in particular a position marking (13) for an obstacle (14) to be positioned at the position marking (13), lines (15) and / or road markings (16), which are arranged at a predetermined distance from one another. Projection system (3) according to one of claims 1 to 3, wherein the control unit (4) is designed to use a hardware control signal to change an orientation in space and / or position of the projection device (7) so that the actual position and match the target position. Projection system (3) according to one of claims 1 to 4, wherein the control unit (4) is designed to use a software control signal to change the image projected by the projection device (7) onto the background (9) in such a way that the actual Position and the target position match. Projection system (3) according to one of claims 1 to 5,

- wherein the projection system (3) has target position markers (91) which can be attached to the surface (9) of the test stand (1),

- wherein the camera (10) is designed to capture the target position markers (91) in the form of the image data, and

- The control unit (4) is designed to determine the target position of the image projected onto the surface (9) based on the target position markers (91) contained in the image data. Projection system (3) according to one of claims 1 to 6,

- wherein the camera (4) is designed to capture a motor vehicle (11) located on the surface (9) of the test bench (1) in the form of image data, and

- The control unit (4) is designed to determine the target position of the image projected onto the surface (9) based on the motor vehicle (11) contained in the image data. Projection system (3) according to one of claims 1 to 7, wherein the camera (10) is connected to a storage device which is designed to store the image data recorded by the camera (10). Test bench (1) for driving assistance systems of a motor vehicle (11), comprising: - The projection system (3) according to one of claims 1 to 8, and

- A support system (5) which can be adjusted in height by the control unit (4) and to which the projection system (3) is at least partially attached. Use of a projection system (3) according to one of claims 1 to 8 on a test bench (1) for driving assistance systems of a motor vehicle.