WO2020052874A1

WO2020052874A1 - Calibration system and calibration method for a detection device of a vehicle

Info

Publication number: WO2020052874A1
Application number: PCT/EP2019/071431
Authority: WO
Inventors: Sascha Spee; Mauro Disaro
Original assignee: Robert Bosch Gmbh
Priority date: 2018-09-10
Filing date: 2019-08-09
Publication date: 2020-03-19
Also published as: DE102018215316A1

Abstract

The invention relates to a calibration system for a detection device of a vehicle, which is, in particular, more flexible in its application. The proposed calibration system (100) for a detection device (210) of a vehicle (200) comprises a projection panel (110), a projector (120) designed to project a calibration pattern (121) onto the projection panel (110), a camera (120) designed to capture the projection panel (110), and a data processing device (140) designed to determine a geometric transformation that is to be applied to the projected calibration pattern (121), on the basis of the capture of the projection panel (110) by the camera (120). The invention also relates to a calibration method.

Description

description

Title:

Calibration system and calibration method for a vehicle detection device

The present invention relates to a calibration system for calibrating a detection device of a vehicle. The invention further relates to a calibration method for such a detection device, as well as a program element and a computer-readable medium.

State of the art

A detection device of a vehicle, such as a camera, a radar system, a LIDAR system or the like, for example for a

Driver assistance system (in English: ADAS - Advanced Driver Assistance Systems) is usually calibrated in order to achieve a correct function in ferry operation. This can be done by the vehicle manufacturer for delivery of the vehicle, but also during the vehicle life cycle in workshops, e.g. as part of a repair.

Usually, calibration boards and / or calibration mats are required for this, which are made on the one hand for the specific vehicle type and on the other hand delivered to the vehicle manufacturer, the workshops etc. and kept there in stock. This means a lot of effort in terms of logistics, warehousing, deployment costs, etc.

Disclosure of the invention

Embodiments of the invention provide an improved calibration system or an improved calibration method for calibrating a Detection device of a vehicle is available, which in particular can allow greater flexibility. These are the subject of

independent claims. Advantageous further developments of the invention result from the dependent claims, the description and the accompanying figures.

A proposed calibration system for a detection device of a vehicle comprises a projection surface, a projector which is set up at least for projecting a calibration pattern onto the projection surface, a camera which is set up to detect the projection surface, and a data processing device which is set up to carry out a geometric To determine the transformation of the calibration pattern to be projected on the basis of the detection of the projection surface by the camera.

The projection surface can be attached to a holding device or provided with such a device. It can also be one size, i.e. with regard to their type and / or size not specific to the vehicle

be designed. The camera can be a mono system, possibly also a

Stereo system, and can in principle be arranged in any relative position to the projection surface, provided that this is in the field of view of the camera, which is why an angle between the projection surface and the camera can possibly also be included. The arbitrary reference position also enables the components of the calibration system to be fixed in a fixed position at fixed positions. The data processing device can be a computerized system, e.g. with a processor, a storage device or a computer-readable storage medium etc., and also be set up for the actual calibration of the detection device. It is also conceivable that the camera and the data processing device

Form unit. Furthermore, the data processing device and / or the camera can be set up for pattern recognition, that is to say, for example, comprise a classifier, a neural network set up for this purpose or the like. In this context, a geometric transformation can be understood in particular to mean that an object to be projected or projected by the projector is moved, enlarged, reduced, rotated, mirrored, etc., especially within a coordinate system or between different coordinate systems.

The calibration system can have several advantages. In principle, any calibration pattern for a large number of different vehicle types and / or different detection devices can be generated flexibly, the hardware being retained. This can

logistical effort for the worldwide provision of a variety

different calibration systems can be reduced. Instead, new vehicle types, new detection devices, etc. can be reacted to extremely flexibly and the respective provision of the adapted one

Calibration system simply as e.g. Software update done. In addition, in principle only a single calibration system has to be maintained that can be used for a multitude of requirements. Also regarding the

Setting up the calibration system can save effort, since an offset of the projection surface to the detection device to be calibrated or to the vehicle equipped with it and / or to the camera can be easily compensated for by the geometric transformation.

A further development provides that the projection surface can have a plurality of first reference markers. In particular for the determination of the geometric transformation, it has proven to be advantageous if at least three first ones, preferably arranged in known positions

Reference markers are arranged. The geometric shape and / or size can be determined relatively freely, a circular shape in particular having proven to be advantageous for recognition by the camera and / or the data processing device. The first reference markers can be printed, glued, etc., for example.

Another development provides that the calibration system,

in particular the projector can be set up to project a plurality of second reference markers onto the projection surface. In principle, these can match or be similar to the physical, first reference markers. According to a further development, the data processing device and / or the camera can be set up, on the basis of the acquired first and second reference markers, for the calibration pattern to be projected

determine the geometric transformation to be performed. In particular, the position of the first reference markers and the position of the second reference markers can be estimated by capturing them with the camera and the geometric transformation can be estimated therefrom.

For a high-quality calibration result, without having to convert the

Calibration system, it can be advantageous if the projector for

Projecting the calibration pattern can be controlled so that a plurality of different angles of view of the calibration pattern can be simulated. In other words, the calibration system, in particular the data processing device, can project the calibration pattern in such a way that it appears to a viewer or the detection device viewed from a different perspective. As a result, neither the position of the calibration system nor of the vehicle or the detection device need to be changed.

A further development provides that the projected calibration pattern can be specific to the vehicle type. In other words, a large number of different calibration patterns for different driver assistance systems and / or vehicle types can be projected, recognized, geometrically transformed, etc.

become. As a result, the deployment effort can be reduced even further.

According to a further development, the detection device can

Vehicle cameras such as a mono or stereo camera, a radar system, a LIDAR system and the like. The calibration system can be flexibly adapted to it, for example due to the geometric transformation.

A proposed method for calibrating a detection device of a vehicle can be carried out, for example, using the calibration system described above and provides for the following steps: - Detecting a projection surface, which has a plurality, in particular two, three or more, of first reference markers by one

Camera. The camera can be arranged at any position relative to the projection surface, provided that there is a clear field of view on it.

- Projecting a plurality, in particular two, three or more, of second reference markers onto the projection surface by a projector. The projector can be positioned at any relative position to the

Projection area and / or the camera can be arranged, provided there is a free projection field to the projection area.

- Determine a geometric transformation for one on the

Projection area to be projected calibration pattern based on the first and / or second reference markers by a

Data processing device. The geometric transformation can compensate for the relative positions to one another from the projection surface, the camera and the projector, and in particular also to a spatial offset from one another.

- Projecting the calibration pattern onto the projection surface by the projector based on the determined geometric transformation. In other words, the calibration pattern can be based on the

geometric transformation are projected so that the respective relative position of the components of the calibration system can be compensated.

The calibration system explained above can be operated with the method. In principle, the advantages described for this can be achieved.

A further development provides that when determining the geometric

Transformation a relative position of the projection surface to the vehicle is compensated with. While with conventional calibration systems an exact alignment of the projection surface with respect to the vehicle is necessary, this effort can be reduced with the proposed method. According to a further development, a dynamically changing one

Calibration patterns are projected. This means that the calibration system can be used even more flexibly.

A proposed program element, if it is executed on a processor, in particular the calibration system described above, can instruct the processor to carry out the method described above for calibrating a detection device of a vehicle. The implementation of the method can also involve an interaction of the

Calibration system with a user through a suitable

Include user interface and therefore does not have to be fully automatic.

Computer-readable medium with the program element described above is also proposed. The computer-readable medium can, for example, be a physical data carrier or a data carrier, e.g. the Internet, be a transferable record.

Further measures improving the invention are described below together with the description of the preferred exemplary embodiments of the invention with reference to figures.

Brief description of the figures

In the following, advantageous exemplary embodiments of the invention are described in detail with reference to the accompanying figures. Show it:

Figure 1 is a schematic overview of a calibration system for

Calibration of a detection device of a vehicle,

Figure 2 is a schematic overview of a calibration system for

Calibration of a detection device of a vehicle and

FIG. 3 shows a flow chart of a calibration method. The figures are only schematic and are not to scale. In the figures, the same, equivalent or similar elements are provided with the same reference numerals throughout.

Embodiments of the invention

FIG. 1 shows a calibration system 100, which is used to calibrate a detection device 210 arranged in a vehicle 200, e.g. a driver assistance system. The detection device 210 is designed, for example, as a camera system, radar system, LIDAR system or the like.

The calibration system 100 is implemented in a computer-assisted manner and comprises a projection surface 110, a projector 120, a camera 130 and a data processing device 140 (see FIG. 2). From a functional point of view, the camera 130 can be viewed as monitoring means for the interaction of the projector 120 and the projection surface 110, as will be explained further below. It should be noted that therefore the position of the projector 120 and / or camera 130 relative to the projection surface 110 and / or the

Vehicle 200 is essentially arbitrary, provided that projection surface 110 can be illuminated or captured as completely as possible, as is indicated in FIG. 1 (and similarly in FIG. 2) by different orientations of projector 120 and camera 130.

In the simplest case, the projection surface 110 can be a type of blackboard or, if appropriate, also have a frame for enclosing and / or stretching the actual projection surface in the manner of a screen or the like. The projector 120 is set up to project a calibration pattern 121 (see FIG. 2) onto the projection surface 110 and can be activated, for example, by the data processing device 140 (see FIG. 2). The camera 130 is set up to capture the projection surface 110. The data processing device 140 is set up to determine a geometric transformation of the calibration pattern 121 to be projected on the basis of the detection of the projection surface 110 by the camera 130. FIG. 2 shows the projection surface 110 in a front view, that is to say in principle from a possible perspective that the detection device 210 of the vehicle 200 to be calibrated can have relative to the projection surface 110. The

Projection screen 110 has several, here four exemplary, first ones

Reference markers 111, which can be printed, glued or otherwise physically applied there. As indicated here with a dashed line, the projector 120 is also set up to project second reference markers 122 onto the projection surface 120 or into the field of view of the camera 130, four of which are shown here by way of example. In practice, at least three first and / or second reference markers 111, 122 have proven to be useful. The camera 130 is also set up to optically detect the first and second reference markers 111, 122 and to determine from them either itself or by means of the data processing device 140 a geometric transformation by means of which the projector 120 can be controlled such that the calibration pattern projected by it 121 with regard to the spatial arrangement of projector 130 and possibly the one to be calibrated

Detection device 210 can be compensated or corrected relative to the projection surface. In Figure 2 it is indicated that the

Data processing device 140 are functionally connected to the projector 120 and the camera 130, either by lines, via a

Radio connection or the like can be realized. The calibration system 100 is also set up to simulate different viewing angles on the calibration pattern 121 by the projector 120, so that the

Relative positions of the detection device 210 and the calibration system 100 with respect to one another do not have to be changed in order to nevertheless have a

to be able to perform viewing angle-dependent calibration of the detection device 210.

FIG. 3 summarizes in a flow chart a method for calibrating the detection device 210 or for operating the calibration system 100. In a step S1, the camera 130 optically detects the projection surface 110 and, in an optional step Sil, determines or estimates the position of the first reference markers 111 by the calibration system 100, for example by the data processing device 140 and / or the camera 130. In one step S2, the projector 130 projects the second reference markers onto the Projection screen 110. This can also be done only temporarily. In a step S3, the calibration system 100 determines, for example, by the

Data processing device 140, a geometric transformation, which is conducive to the projection of the calibration pattern 121 onto the projection surface 110 for an in particular distortion-free, positional and positional calibration, on the basis of the acquired first and / or second reference markers 111, 122. In a step S4 then the calibration pattern 121 onto the projection surface 110 by the projector 120 on the basis of the geometric transformation determined in step S3.

Claims

Expectations

1. Calibration system (100) for a detection device (210)

Vehicle (200), with

- a projection surface (110),

- A projector (120) for projecting a

Calibration pattern (121) is set up on the projection surface (110),

- A camera (120), which is set up to capture the projection surface (110), and

- A data processing device (140) which is set up to determine a geometric transformation to be carried out of the calibration pattern (121) to be projected on the basis of the detection of the projection surface (110) by the camera (120).

2. Calibration system (100) according to claim 1, characterized in that the projection surface (110) has a plurality of first reference markers (111).

3. Calibration system (100) according to claim 1 or 2, characterized

characterized in that the projector (120) is set up to a

Project a plurality of second reference markers (122) onto the projection surface (110).

4. Calibration system (100) according to claim 2 and 3, characterized in that the data processing device (140) is set up on the basis of the detected first and second reference markers (111, 122)

to determine geometric transformation.

5. Calibration system (100) according to one of the preceding claims, characterized in that the calibration system (100) for this is set up, the projector (120) for projecting the

Control calibration pattern (121) so that a plurality of different angles of view of the calibration pattern (121) can be simulated.

6. Calibration system (100) according to one of the preceding claims, characterized in that the projected calibration pattern (121) is specific to the vehicle type.

7. Calibration system (100) according to one of the preceding claims, characterized in that the detection device (210) is selected from: a vehicle camera, a radar system, a LIDAR system and the like.

8. A method for calibrating a detection device (210)

Vehicle (200), with the steps:

- Capturing a projection surface (110), which has a plurality of first reference markers (111), by a camera (130),

Projecting a plurality of second reference markers (122) onto the projection surface (110) by a projector (120),

- Determine a geometric transformation for one on the

Projection surface (110) to be projected calibration pattern (121) based on the first and / or second reference markers (111, 122) by a data processing device (140),

- Projecting the calibration pattern (121) onto the projection surface (110) by the projector (120) on the basis of the determined geometric transformation.

9. The method according to claim 8, characterized in that when determining the geometric transformation, a relative position of the projection surface (110) to the vehicle (200) is also compensated.

10. The method according to claim 8 or 9, characterized in that a dynamically changing calibration pattern (121) is projected.

11. Program element that, when on a processor one

Calibration system (100) is executed, the processor instructs to carry out a method according to any one of claims 8 to 10.

12. Computer-readable medium, with a program element according to the preceding claim.