DE102021126367A1 - Method and device for determining the position of a portable reference sensor system in relation to a vehicle - Google Patents

Abstract

Method for determining the position of a portable reference sensor system relative to a vehicle using a calibration object which is arranged on a surface of the vehicle, a first position of the calibration object relative to the vehicle being determined, comprising the method steps: attaching the reference sensor system to the vehicle; recognizing the calibration object and determining a second position of the reference sensor system relative to the calibration object using the reference sensor system;determining a third position of the reference sensor system relative to the vehicle using the first position and the second position.

Description

The invention relates to a method for determining the position of a portable reference sensor system in relation to a vehicle. The invention further relates to a device that can carry out such a method.

The statistical evaluation of large quantities of representative real driving data to evaluate the performance of driver assistance system (ADAS) sensors and their algorithms becomes all the more important the higher the degree of automation (SAE level 0 to 5) of a vehicle. The objective comparison of the sensor signals against an absolute environmental reference is the only way to implement cost-efficient and reliable sensor development and validation. Manufacturer-independent, standardized reference sensor systems are nevertheless a basic requirement for the homologation/type approval of future automated vehicles, since the relevant certification authorities will always base their assessment on their own environment image. Development companies that see the technological step towards autonomous driving as a crucial part of their business model consistently pursue the approach of data-driven development for the continuous improvement and optimization of their products. Every further development, every new iteration of the products is constantly tested against the existing database and continuously optimized on the basis of the analysis results generated from it.

The vehicle sensors or the vehicle sensor system, which is able to record, understand and reconstruct the static and dynamic environment of a vehicle, are decisive for the autonomous driving of vehicles. For this purpose, each vehicle sensor of the vehicle sensor system uses its own coordinate system, in which at least a section of the environment in the respective detection area of the sensor is recorded. In order to be able to reconstruct the entire vehicle environment and to be able to establish a geometric relationship between the respective coordinate systems of the sensors, it is necessary for the relative positions between all sensors of the vehicle sensor system and the vehicle to be determined and calibrated.

For the development, calibration and validation of vehicle sensor systems or of vehicles that include a vehicle sensor system, a standard, portable reference sensor system for all vehicles is used in the prior art. First, any vehicle is equipped with the reference sensor system. In order to be able to compare the sensor signals of the vehicle sensor system with the sensor signals of the reference sensor system, it is necessary in the following step to calibrate the reference sensor system to the vehicle or to determine the position of the portable reference sensor system in relation to the vehicle. In the prior art, an external calibration device is used for this purpose, for example a motion capture system. The disadvantage of calibrating using an external calibration device is that the calibration is tedious and time-consuming. Especially with large vehicle fleets, which are necessary to generate the required amount of sensor data while driving in a wide variety of vehicle environments (climatic conditions, weather, road conditions, traffic conditions, etc.), the management of a large-scale series of measurements is particularly difficult. The portable reference sensor system and the external calibration device represent the limiting resources. If all sensors of the vehicle sensor system and all sensors of the reference sensor system are calibrated to one another or the respective positions are known, the respective sensor data can be recorded and compared with one another.

If the reference sensor system is removed from the vehicle and reinstalled on the vehicle at a later point in time, the reference sensor system must also be calibrated again on the vehicle using the external calibration device in order to achieve the required measurement tolerances of the order of millimeters with respect to a shift or tenths of a degree with respect to a to keep rotation. In practice, this means that this vehicle has to be brought back to the external calibration facility in order to calibrate the reference sensor system to the vehicle. This further makes the calibration process time consuming and expensive. Another disadvantage is that the vehicle must be equipped with the reference sensor system in order to calibrate the reference sensor system on the vehicle using the external calibration device, so that this reference sensor system is not available for other purposes at the same time, for example for the acquisition of sensor data while driving.

It is therefore the object of the present invention to provide a method that overcomes the disadvantages of the method for determining the position of the portable reference sensor system compared to a vehicle in the prior art.

This object is achieved by a method having the features of patent claim 1. Advantageous embodiments result from the dependent claims.

1. a) Anbringen des Referenzsensorsystems an das Fahrzeug;
2. b) Erkennen des Kalibrierobjektes und Bestimmen einer zweiten Position des Referenzsensorsystems gegenüber dem Kalibrierobjekt mittels des Referenzsensorsystems;
3. c) Bestimmen einer dritten Position des Referenzsensorsystems gegenüber dem Fahrzeug unter Verwendung der ersten Position und der zweiten Position.

The core idea of the invention is a method for determining the position of a portable reference sensor system relative to a vehicle using a calibration object which is arranged on a surface of the vehicle, a first position of the calibration object relative to the vehicle being determined, comprising the method steps:

1. a) attaching the reference sensor system to the vehicle;
2. b) detecting the calibration object and determining a second position of the reference sensor system relative to the calibration object by means of the reference sensor system;
3. c) determining a third position of the reference sensor system relative to the vehicle using the first position and the second position.

In particular, the position of the portable reference sensor system relative to the vehicle is to be determined by the method. The vehicle has its own coordinate system, the origin of which is usually defined in the middle of the rear axle of the vehicle. The coordinate system of the vehicle is usually directed in such a way that the three axes are directed in a forward direction, in a height direction and in a lateral direction, which are orthogonal to each other. The portable reference sensor system also has its own coordinate system, the zero point of which can be defined, for example, in the geometric center of the reference sensor system or in a sensor unit of the reference sensor system. The three axes of the reference sensor system are usually directed in a forward direction, in a vertical direction and in a lateral direction of the reference sensor system. In order to determine the position of the reference sensor system relative to the vehicle, it is particularly necessary to determine a shift or translation (e.g. by means of a vector) of the zero point of the coordinate system of the reference sensor system to the zero point of the coordinate system of the vehicle, in particular to the millimeter. In addition, it is necessary to determine a rotation of the coordinate system of the reference sensor system with respect to the coordinate system of the vehicle. Ideally, the two coordinate systems do not rotate with respect to each other, but small deviations are possible, it being necessary to determine deviations of the order of a tenth of a degree.

According to the invention, the method is carried out using the calibration object, which is arranged on the surface of the vehicle. In particular, the calibration object is firmly connected to the surface of the vehicle and is intended to be permanently arranged in a fixed position relative to the vehicle, which is referred to as the first position.

According to the invention, the first position of the calibration object relative to the vehicle has already been determined. In particular, the calibration object also has its own coordinate system, with a displacement or translation of the origin of the coordinate system of the calibration object to the origin of the coordinate system of the vehicle, and the rotation of the coordinate system of the calibration object to the coordinate system of the vehicle being determined by the first position. The information on the first position forms the basis of the method and is stored accordingly and can be called up accordingly in the method.

Due to the fact that the calibration object is fixed and permanently arranged on the surface of the vehicle, the first position of the calibration object is also fixed and permanently determined. This means that the first position is or must be determined only once or exactly once. For the method, this means that the first position must be determined inertially before the method according to the invention is carried out for the first time. Accordingly, the first position no longer has to be determined for each further or subsequent implementation of the method according to the invention, since the first position is unchangeable. Thus, the determination of the first position is not a step of the method.

In order to determine the position of the calibration object relative to the vehicle, an external calibration device is preferably used, more preferably a motion capture system. Furthermore, the method assumes that the reference sensor system is already intrinsically calibrated.

In a first method step, the reference sensor system is attached to the vehicle. In particular, the reference sensor system is detachably connected to the vehicle, preferably plugged, screwed, clamped, sucked or the like onto the vehicle. The necessary infrastructure, for example for the power supply and data transfer to operate the reference sensor system, is preferably installed in the trunk of the vehicle.

The calibration object is then recognized by the reference sensor system. For this it is necessary in particular that the calibration object is located in a detection range of the reference sensor system.

Then the position of the reference sensor system relative to the calibration object, the is defined as the second position can be determined by means of the reference sensor system. In particular, the second position is determined by a shift or translation of the origin of the coordinate system of the reference sensor system to the origin of the coordinate system of the calibration object, and the rotation of the coordinate system of the reference sensor system to the coordinate system of the calibration object.

Finally, the position of the reference sensor system relative to the vehicle, referred to as the third position, is determined using the first position and the second position by means of the reference sensor system.

$${\text{T}}_{3.\text{Position}}={\text{R}}_{1.\text{Position}}*{\text{T}}_{2.\text{Position}}+{\text{T}}_{1.\text{Position}}$$

In particular, the rotation (R) and the translation (T) of the third position can be calculated from the respective translation (T) and rotation (R) of the first position and second position as follows: $${\text{<figure-callout id="3" label="R" filenames="DE102021126367A1\_0005.png" state="{{state}}">R</figure-callout>}}_{3.\text{position}}={\text{<figure-callout id="2" label="R" filenames="DE102021126367A1\_0004.png" state="{{state}}">R</figure-callout>}}_{2.\text{position}}*{\text{R}}_{1.\text{position}}$$

$${\text{<figure-callout id="3" label="T" filenames="DE102021126367A1\_0005.png" state="{{state}}">T</figure-callout>}}_{3.\text{position}}={\text{R}}_{1.\text{position}}*{\text{<figure-callout id="2" label="T" filenames="DE102021126367A1\_0004.png" state="{{state}}">T</figure-callout>}}_{2.\text{position}}+{\text{T}}_{1.\text{position}}$$

Thus, the determination of the position of the portable reference sensor system relative to the vehicle can only be determined by means of the vehicle with the calibration object and the reference sensor system. The first position is already available to the method as information that can be called up. The detection of the calibration object and the determination of the second and third position can be guaranteed and fully automated solely by the reference sensor system, so that no further actions by an operator are necessary. The portable reference sensor system calibrates its position to the vehicle more or less independently as soon as the reference sensor system or the vehicle is started.

After the reference sensor system has been calibrated, this system is preferably provided to record the vehicle surroundings in the form of real driving data while the vehicle is being driven. The real driving data from the reference sensor system can then be compared with real driving data from a vehicle sensor system in order to validate them.

According to a preferred embodiment, the method is carried out independently of an external calibration device. An external calibration device is to be understood in particular as a device that would be required in addition to the vehicle with the calibration object and reference sensor system. For example, the external calibration device is a stationary motion capture system that is permanently installed in a test hall.

In particular, it is possible to carry out the method at any location without additional devices. With the help of the method, the portable reference sensor system can thus advantageously be attached and calibrated from one vehicle to another vehicle in a real vehicle environment, such as in city traffic, without the vehicle having to be driven to an external calibration device with the reference sensor environment attached. Thus, time and money for position determination can be saved, the management of a test series can be simplified and resources of an external calibration device can be saved.

According to a preferred embodiment, a calibration pattern of the calibration object is defined in the method. In particular, this means that information about the geometry of the calibration pattern is available or can be called up by the method. Furthermore, in particular dimensions such as lengths and angles of the calibration pattern or coordinates of distinctive points of the calibration pattern in the coordinate system of the calibration object are known and the method is based on information. The calibration pattern, in particular the distinctive points, is preferably particularly easy to recognize by the reference sensor system. This is achieved, for example, through high color contrasts and sharp color edges.

The calibration pattern is preferably a simple or repeating pattern. More preferably, the calibration pattern is a checkerboard pattern or a dot pattern. In addition, any other pattern which proves to be particularly suitable for the method can be used.

According to a preferred embodiment, the reference sensor system includes a first sensor unit which, according to method step b), recognizes the calibration pattern. In particular, the calibration object or the calibration pattern is located in the detection range of the first sensor unit.

The first sensor unit is preferably an optical sensor or a high-resolution camera that captures an image of the calibration pattern consisting of pixels. The image preferably has 3.2 Mpixels, more preferably 9 Mpixels or more. In particular, the first sensor unit is capable of recognizing and classifying all detected dynamic and static objects in the vehicle environment in its detection range and in particular the calibration pattern on the vehicle surface with the aid of several powerful neural networks (CNNs).

It is thus possible to use at least the coordinates of a distinctive point of the calibration pattern in the coordinate system of the calibration object assigned to a pixel of the image, each pixel having a pixel coordinate in the image or in a pixel coordinate system. Consequently, a pixel coordinate can be assigned to the respective coordinate of a respective distinctive point of the calibration pattern in the coordinate system of the calibration object.

According to a preferred embodiment, the second position of the reference sensor system relative to the calibration object can be determined according to method step b) using the image of the calibration pattern and the defined calibration pattern.

Due to the fact that the geometry of the calibration pattern or each coordinate of prominent points of the calibration pattern in the coordinate system of the calibration object are exactly defined and known, and also the associated pixel coordinates in the pixel coordinate system that map the prominent points of the calibration pattern, the second position can consequently be calculated . For this purpose, it is also necessary in particular for the first sensor unit to be calibrated accordingly in advance. The intrinsic calibration of the first sensor unit is in particular also given or is known in the method.

The calculation of the second position can be expressed mathematically by the following system of equations: $$\left[\begin{array}{c}\mathrm{and}\\ v\\ 1\end{array}\right]=\left[\begin{array}{ccc}{f}_x& 0& c_x\\ 0& f_{\mathrm{<figure-callout\; id="0"\; label="y\; c\; y"\; filenames="DE102021126367A1\_0004.png"\; state="\{\{state\}\}">y</figure-callout>}}& c_y{}_{}\\ 0& 0& 1\end{array}\right]\left[\begin{array}{cccc}{\mathrm{right}}_{11}& {\mathrm{right}}_{12}& {\mathrm{right}}_{13}& t_1\\ {\mathrm{right}}_{21}& {\mathrm{right}}_{22}& {\mathrm{right}}_{23}& {\mathrm{<figure-callout\; id="2"\; label="t"\; filenames="DE102021126367A1\_0004.png"\; state="\{\{state\}\}">t</figure-callout>}}_2\\ {\mathrm{right}}_{31}& {\mathrm{right}}_{32}& {\mathrm{right}}_{33}& t_3\end{array}\right]\left[\begin{array}{c}X\\ Y\\ Z\\ 1\end{array}\right]$$

X, Y, Z

Koordinaten eines Punktes im Koordinatensystem des Kalibrierobjektes;

u, v

Pixelkoordinaten des zugehörigen Pixels eines Punktes des Kalibrierobjektes im Pixelkoordinatensystem;

3×3 Matrix

Kalibriermatrix der intrinsisch kalibrierten ersten Sensoreinheit;

cx, cy

Pixelkoordinate eines Bezugspunktes (im Zentrum des Bildes);

fx, fy

Brennweite einer Linse der Sensoreinheit, ausgedrückt in Pixelkoordinaten;

3×4 Matrix

Transformationsmatrix zur Positionsbestimmung einer zweiten Position des Referenzsensorsystems gegenüber dem Kalibrierobjekt;

r

Rorationsparameter;

t

Translationsparameter.

The parameters are defined as follows:

X,Y,Z

Coordinates of a point in the coordinate system of the calibration object;

u, v

Pixel coordinates of the associated pixel of a point of the calibration object in the pixel coordinate system;

3×3 matrix

calibration matrix of the intrinsically calibrated first sensor unit;

cx, cy

Pixel coordinate of a reference point (at the center of the image);

fx, fy

focal length of a lens of the sensor unit, expressed in pixel coordinates;

3×4 matrix

Transformation matrix for determining a second position of the reference sensor system relative to the calibration object;

right

rotation parameters;

t

translation parameters.

The coordinates X, Y and Z of a prominent point, in particular at least two prominent points or all prominent points in the coordinate system of the calibration object are given or known. The calibration matrix is also known and is also a prerequisite for carrying out the method. A pixel coordinate u and v of an associated pixel of a prominent point can be assigned to each prominent point by the first sensor unit. More will be in the 2 shown. The task is to calculate the transformation matrix with rotation and translation parameters. At least two distinctive points, preferably several distinctive points, are necessary for this, the more precisely the transformation matrix can be determined, the more distinctive points are recognized and assigned.

Various methods can be used to solve the system of equations or to determine the transformation matrix. The Levenberg-Marquardt algorithm is preferably used for the solution. The coordinate system of the reference sensor system can be transformed into the coordinate system of the calibration object by translation and rotation using the transformation matrix, so that the second position of the reference sensor system relative to the calibration object can be determined using the reference sensor system.

The calculation of the second position will be performed by the reference sensor system using the second transformation matrix without user intervention.

The object is further achieved by a device according to claim 6. The device can be equipped with all of the features already described above in connection with the method, individually or in combination with one another and vice versa.

According to the invention, a device for carrying out a method for determining the position of a portable reference sensor system in relation to a vehicle, comprising the portable reference sensor system which can be attached to a vehicle, is provided, the device comprising a calibration object which is applied to a surface of the vehicle and is defined by the reference limit sensor system can be identified, with a first position of the calibration object relative to the vehicle being determined and a second position of the reference sensor system relative to the calibration object being determinable, so that a third position of the reference sensor system relative to the vehicle using the first position and the second position can be determined.

Accordingly, this device is capable of carrying out the method according to claims 1-5, the method preferably being able to be carried out by means of the device and independently of an external calibration device.

According to a preferred embodiment, the portable reference sensor system can be attached at least partially to a roof of the vehicle. The reference sensor system preferably includes a roof box that can be attached to any commercially available vehicle roof. In particular, the reference sensor system can be detachably connected to the vehicle, preferably plugged, screwed, clamped, sucked or the like onto the vehicle. The necessary infrastructure, for example for the voltage supply and the data transfer in order to operate the reference sensor system, can preferably be accommodated in the trunk of the vehicle.

This has the advantage that the reference sensor system can be quickly converted from one vehicle to another vehicle. Furthermore, when positioned on the roof of the vehicle, it is possible for the reference sensor system to generate a holistic 360° reference data record of the vehicle's surroundings.

In contrast to chassis-integrated reference sensor systems, in which the reference sensors are integrated into the body of the respective test vehicle, the arrangement on the vehicle roof has the further advantage that the data set generated with the reference sensor system remains homogeneous across different vehicle models. This means that every development department of a vehicle manufacturer can access the same holistic 360° reference data set. This avoids redundant, function-specific reference data sets and the resulting duplication of work, which is difficult or impossible to compare with one another.

The reference sensor system is preferably the AVL Dynamic Ground Truth (DGT) system.

According to a preferred embodiment, the calibration object is an adhesive film. The adhesive film is preferably glued to the surface of the vehicle. More preferably, the adhesive film is glued to the hood of the vehicle. The adhesive film preferably has the calibration pattern on its surface. A first sensor unit, which preferably detects the adhesive film in its detection area, is therefore preferably a front camera of the reference sensor system.

According to a preferred embodiment, the portable reference sensor system includes at least one computing unit. The computing unit is in particular able to determine the second position and the third position, preferably using the method according to claim 5. The reference sensor system preferably also comprises a first sensor unit according to claim 4. The reference sensor system preferably also comprises a memory unit. The reference sensor system preferably includes at least one second sensor unit. The at least one second sensor unit is preferably at least one selected from the group comprising lidar sensors, radar sensors, high-resolution cameras, ultrasonic sensors, infrared sensors and receivers of signals from a navigation satellite system. Detected sensor data of the reference sensor system can preferably be processed by the computing unit and stored in the memory unit.

The detection range of all sensor units is preferably optimized for maximum coverage of the vehicle environment in 360° around the vehicle in order to ensure that the reference data can be used for as many Advanced Driver Assistance System (ADAS) functions as possible.

According to a preferred specific embodiment, the vehicle includes a vehicle sensor system, in which case detected sensor data from the vehicle sensor system can be compared with detected environmental data from the reference sensor system of the vehicle environment. The vehicle sensor system is preferably at least part of a driver assistance system (ADAS).

In particular, the vehicle sensor system is calibrated to the vehicle so that dynamic and static objects can be detected, classified and positioned in relation to the vehicle. In particular, the comparison of the sensor data is possible because the third position of the reference sensor system relative to the vehicle can be determined by the device and thus dynamic and static objects can also be detected, classified and positioned in relation to the vehicle.

• 1 einen schematischen Aufbau einer Vorrichtung gemäß einer bevorzugten Ausführungsform;
• 2 eine Prinzipdarstellung einer Zuordnung von markanten Punkten zu Pixelkoordinaten;

Further objects, advantages and advantages of the present invention are presented below ender drawings and the following description explained. Here show:

• 1 a schematic structure of a device according to a preferred embodiment;
• 2 a schematic representation of an assignment of prominent points to pixel coordinates;

The 1 shows a schematic structure of a device 100 according to a preferred embodiment. The device 100 comprises a vehicle 1, which can be any vehicle model and does not have to correspond to the vehicle model shown. The device 100 further includes a portable reference sensor system 2, which is arranged on the vehicle roof with a housing in the form of a roof box. The infrastructure required for the reference sensor system is preferably accommodated in the trunk of the vehicle, not shown here. The reference sensor system 2 includes at least a first sensor unit 5. The sensor unit 5 is preferably a front camera 5 of the reference sensor system 2. The device further includes the calibration object, which is in the detection area 4 of the front camera 5, preferably as an adhesive film 3a. The adhesive film 3a is stuck onto the hood and preferably has a calibration pattern 14 . This is in the 2 to recognize. The position of the adhesive film 3a relative to the vehicle 1 is precisely defined as the first position. The reference sensor system 2 further includes at least one second sensor unit 6, wherein in the 1 two sensor units 6 are shown. The respective detection areas of the first sensor unit 5 and the second sensor units 6 preferably cover the vehicle surroundings in a 360° area around the vehicle 1 .

The coordinate system 13 of the vehicle 1 preferably has its origin in the middle of the rear axle of the vehicle. The axes of the coordinate system 13 are directed such that these axes are directed in a forward direction, in a height direction, and in a lateral direction, which are orthogonal to each other. The coordinate system 10 of the calibration object 3 and the coordinate system 11 of the reference sensor system 2, which in this representation has its origin in the first sensor unit 6, for example, are in FIG 1 also shown.

The 2 shows a schematic representation of an assignment of prominent points to pixel coordinates. The calibration object 3 has a calibration pattern 14 . In this example, the calibration pattern 14 is a dot pattern 14a. For example, as shown, salient points are arranged in a grid-like manner, equally spaced in a plane, with rows and columns perpendicular to one another. In particular, the distances between the prominent points are known and are known in relation to a coordinate system 10 of the calibration object 3 and are defined in the method. In particular, the coordinates of the prominent points of the calibration pattern 14 in the coordinate system 10 of the calibration object 3 are known. For example, a prominent point 8 has the coordinates (0; -2; 3). The first sensor unit 5 recognizes the prominent points with the aid of a number of powerful neural networks (CNNs) and assigns them to at least one pixel or pixel coordinate. For example, as in the 2 shown, the prominent point 8 is assigned to the pixel 9, the pixel 9 being assigned a pixel coordinate in the pixel coordinate system 12.

Due to the intrinsic calibration of the first sensor unit 11 and the known geometry of the calibration object 3 or the calibration pattern 14, a coordinate in the coordinate system 11 of the reference sensor system 2 can be assigned to a prominent point of the calibration object 3, so that the second position can be determined.

It goes without saying that the embodiments explained above are only a first configuration of the device according to the invention. In this respect, the configuration of the invention is not limited to these exemplary embodiments.

All features disclosed in the application documents are claimed to be essential to the invention, provided they are new compared to the prior art, either individually or in combination.

reference list

100

contraption

1

vehicle

2

portable reference sensor system

3

calibration object

3a

adhesive film

4

Detection range of the first sensor unit

5

first sensor unit

6

second sensor unit

7

Picture

8th

distinctive point of the calibration object

9

pixels of the image

10

Coordinate system of the calibration object

11

Coordinate system of the reference sensor system

12

pixel coordinate system

13

Coordinate system of the vehicle

14

calibration pattern

14a

Dot pattern

Claims (10)

Method for determining the position of a portable reference sensor system (2) relative to a vehicle (1) using a calibration object (3) which is arranged on a surface of the vehicle (1), a first position of the calibration object (3) relative to the vehicle (1) being determined is, comprising the process steps: a) attaching the reference sensor system (2) to the vehicle (1); b) detecting the calibration object (3) and determining a second position of the reference sensor system (2) relative to the calibration object (3) by means of the reference sensor system (2); c) determining a third position of the reference sensor system (2) relative to the vehicle (1) using the first position and the second position. procedure after claim 1 , characterized in that the method is carried out independently of an external calibration device. procedure after claim 1 or 2 , characterized in that a calibration pattern (14) of the calibration object (3) is defined, the calibration pattern preferably being a checkerboard pattern or a dot pattern (14a). procedure after claim 3 , characterized in that the reference sensor system (2) comprises a first sensor unit (5) which detects the calibration pattern (14), the first sensor unit (5) being an optical sensor which generates a pixel image (7) of the calibration pattern ( 14) depicts. procedure after claim 4 , characterized in that the second position of the reference sensor system (2) relative to the calibration object (3) using the image (7) of the calibration pattern (14) and the defined calibration pattern (14) can be calculated. Device (100) for carrying out a method for determining the position of a portable reference sensor system (2) relative to a vehicle (1), comprising the portable reference sensor system (2) which can be attached to a vehicle (1), characterized in that the device includes a calibration object ( 3) which is applied to a surface of the vehicle (1) and can be recognized by the reference sensor system (2), a first position of the calibration object (3) relative to the vehicle (1) being determined and a second position of the reference sensor system (2) can be determined relative to the calibration object, so that a third position of the reference sensor system (2) relative to the vehicle (1) can be determined using the first position and the second position. Device (100) according to claim 6 , characterized in that the portable reference sensor system (2) can be attached to a roof of the vehicle (1). Device (100) according to claim 6 or 7 , characterized in that the calibration object (3) is an adhesive film (3a) which is glued to the surface of the vehicle (1). Device (100) according to one of Claims 6 until 8th , characterized in that the portable reference sensor system (2) comprises at least one computing unit, a memory unit and at least one second sensor unit (6), wherein the at least one second sensor unit (6) is at least one selected from the group comprising lidar sensors, radar Sensors, high-resolution cameras, ultrasonic sensors, infrared sensors and receivers of signals from a navigation satellite system, it being possible for recorded sensor data from the reference sensor system (2) to be processed by the computing unit and stored in the memory unit. Device (100) according to one of claim 6 until 9 , characterized in that the vehicle (1) comprises a vehicle sensor system, wherein detected sensor data of the vehicle sensor system with detected sensor data of the reference sensor system (2) can be compared.

Images