Method for measurement error correction, and radar sensor system

Abstract

The invention relates to a method for measurement error correction (10) of at least one measurement variable (22) of a radar sensor (20) which, together with a sensor cover (18), forms a radar sensor system (16), the method comprising: starting up (12) the radar sensor system (16) which is assigned to a sensor-system series (14) and comprises the radar sensor (20) that is arranged behind the sensor cover (18) and that provides the measurement variable (22) affected by a measurement error (M); and, during operation of the radar sensor system (16), compensating (24) for the measurement error (M) by retrieving and applying a correction variable (26) to the measurement variable (22) of the radar sensor (20), wherein the correction variable (26) is a correction variable (26) determined and stored uniformly for the entire sensor-system series (14) before starting up (12) the radar sensor system (16). The invention also relates to a radar sensor system (16).

Description

[0001] R. 416210

[0002] - 1 -

[0003] Description

[0004] title

[0005] Methods for measurement error correction and radar sensor system

[0006] The invention relates to a method for measurement error correction according to the preamble of claim 1. Furthermore, the invention relates to a radar sensor system.

[0007] State of the art

[0008] German patent DE 102022 115 261 A1 describes a method for calibrating a radar sensor. In this method, an individual calibration is performed for each radar sensor located behind a sensor cover and put into operation. Manufacturing tolerances of the radome as well as installation deviations are taken into account simultaneously by performing a measurement cycle with a reference object, determining measurement deviations, and calculating correction values ​​for individual correction cells in the radar sensor's field of view.

[0009] In DE 102013 203574 A1 a method for error compensation of angle measurement errors in a radar sensor is described, in which, during the operation of an installed radar sensor, movement patterns of objects are analyzed by comparison with a second sensor in order to identify and correct deviations between measured and actual angles.

[0010] Disclosure of the invention

[0011] According to the present invention, a method for measurement error correction with the features of claim 1 is proposed. This enables cost-effective and efficient measurement error correction. The radar sensor can exhibit a reduced measurement error. The measurement accuracy of the radar sensor is increased. R. 416210

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[0013] The radar sensor can be located in a vehicle. The vehicle can be a motor vehicle.

[0014] The sensor cover can be a radome, in particular a body component of the vehicle. The sensor cover can be made of a plastic and / or a composite material.

[0015] A sensor system series is a group of radar sensors developed with the aim of sharing common, uniform features, properties, and / or functions. A sensor system series specifically comprises radar sensors of the same product type.

[0016] The measured quantity can be an environmental object within the radar sensor's field of view. The measured quantity can be a distance, a velocity, an angular coordinate, preferably an elevation angle and / or azimuth angle.

[0017] The acquisition of the measured quantity can involve a calculation, a simulation, in particular a full-wave simulation, a ray tracing simulation and / or a measurement.

[0018] The acquisition of the measured quantity and the determination of the correction quantity can be carried out before the initial commissioning of the radar sensor, in particular before the production of the radar sensor system, here the radar sensor and / or the sensor cover.

[0019] The measurement error can arise from the refraction of radar waves at the sensor cover. For example, refraction occurs at the interface between two materials with different permittivities, such as air and the sensor cover material. This can cause a measurement error, for example, in the angular coordinate as the measured quantity.

[0020] The exemplary radar sensor system can be a radar sensor system selected specifically or randomly from the sensor system series. The exemplary radar sensor system can be a sample or a simulation model of a radar sensor system from the sensor system series.

[0021] The determined correction value can be uniformly assigned to the radar sensors of the sensor system series. The determined correction value can be R. 416210

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[0023] independent of individual tolerances of the individual radar sensor installed, in particular independent of tolerances in the individual radar sensor system, in particular tolerances of the sensor cover, the radar sensor and / or the arrangement of the radar sensor in the radar sensor system, in particular with respect to the sensor cover.

[0024] The commissioning of the radar sensor can be an initial commissioning of the radar sensor.

[0025] The application of the correction factor can be an addition and / or multiplication of the correction factor with the measured quantity.

[0026] Applying the correction factor can involve accessing the stored correction factor and calculating it against the measured value. This calculation can include determining the difference.

[0027] The application of the correction parameter to the measured parameter during the operation of the radar sensor can take place in the radar sensor itself or in a central control unit connected to the radar sensor via data transmission.

[0028] In a preferred embodiment of the invention, it is advantageous if the correction factor is determined before commissioning the radar sensor system by detecting at least one measurement error of the measured quantity of an exemplary radar sensor system of the sensor system series that is influenced by a component parameter of the sensor cover, and the correction factor that compensates for the measurement error is determined and stored uniformly for the entire sensor system series, depending on the detected measurement error of the exemplary radar sensor system. The correction factor can be an averaged measurement error. The correction factor can be calculated by regression and / or averaging the measurement error. The correction factor can correspond to an average value and / or a regression of the measurement error.

[0029] The correction size can be limited to a maximum value and / or a maximum gradient to limit the influence of the compensation.

[0030] In a specific embodiment of the invention, it is advantageous if a single measurement error is recorded for each system parameter of the radar sensor system and the correction value depends on the several individual R. 416210

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[0032] Measurement errors are determined and stored. For each individual measurement error, a separate correction value can be determined, and the overall correction value can be calculated based on these individual correction values. The overall correction value can be calculated by averaging the individual measurement errors.

[0033] The system parameter can be the relative position of the radar sensor to the sensor coverage area within the radar sensor system. The system parameter can be an x-position, y-position, or z-position. The x-position and y-position can be defined as Cartesian coordinates spanning a plane in which the azimuth angle is defined.

[0034] A preferred embodiment of the invention is advantageous in which the component parameter is a shape of the sensor cover. The shape can include a curvature or a curvature profile of the sensor cover. Alternatively or additionally, the component parameter of the sensor cover can be a maximum, minimum, or average material thickness or a material of the sensor cover. The component parameter can be the parameter of the sensor cover that primarily influences the refraction of the radar waves between the radar sensor and the sensor cover.

[0035] In a preferred embodiment of the invention, the measured quantity is an angular coordinate, in particular an elevation angle or azimuth angle, and the measurement error is an angular deviation of the angular coordinate. The angular coordinate can be the angular position of the reflection, in particular from an environmental object in the field of view of the radar sensor system, relative to the radar sensor system. The measured quantity can be a signal amplitude as a function of the angular coordinate. The correction quantity can be a correction angle.

[0036] In a preferred embodiment of the invention, it is advantageous if the measurement error exhibits a measurement error profile that depends on the measured quantity. The measurement error can be dependent on the measured quantity.

[0037] A preferred embodiment of the invention is advantageous in which the measurement error profile is a profile of the angular deviation over the angular coordinate. The angular coordinate can be an elevation angle or an azimuth angle. R. 416210

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[0039] In a specific embodiment of the invention, it is advantageous if the correction parameter is a correction curve over the measured quantity. The correction parameter can have multiple correction values. The number of correction values ​​in the stored correction curve can be selected based on the performance of the computing unit executing the method. The correction curve can be parameterized, in particular by polynomial regression, especially linear regression.

[0040] In an advantageous embodiment of the invention, the correction quantity is a correction angle and the correction profile is a profile of the correction angle over the measured quantity. The correction quantity can, for example, comprise correction angles assigned to several angular coordinates.

[0041] According to the present invention, a radar sensor system with the features according to claim 10 is further proposed.

[0042] Further advantages and advantageous embodiments of the invention will become apparent from the description of the figures and the illustrations.

[0043] Character description

[0044] The invention is described in detail below with reference to the illustrations. These show, in detail:

[0045] Figure 1: A method for correcting measurement errors in a special embodiment of the invention.

[0046] Figure 2: A correction curve of a correction parameter of a method for measurement error correction in a further special embodiment of the invention.

[0047] Figure 3: A measurement error curve and a correction curve of a method for measurement error correction in a further special embodiment of the invention. R. 416210

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[0049] Figure 4: A respective correction curve of a correction parameter of a method for measurement error correction in a further special embodiment of the invention.

[0050] Figure 1 shows a method for measurement error correction in a special embodiment of the invention. The method for measurement error correction 10 of at least one measured quantity of a radar sensor forming a radar sensor system with a sensor cover comprises commissioning 12 of the radar sensor system 16, which is assigned to a sensor system series 14 and includes the radar sensor 20 arranged behind the sensor cover 18, which provides the measured quantity 22 subject to a measurement error. During operation of the radar sensor system 16, a compensation 24 of the measurement error is carried out by retrieving and applying a correction quantity 26 to the measured quantity 22 of the radar sensor 20, thereby outputting an error-compensated measured quantity 28.

[0051] The measured quantity 22 is, for example, an angular coordinate 30, and the measurement error is an angular deviation of the angular coordinate 30. The angular coordinate 30 can be an azimuth angle. <p oder ein Elevationswinkel sein.

[0052] The correction parameter 26 is a correction parameter 26 determined uniformly for the entire sensor system series 14 before commissioning 12 of the radar sensor system 16 and stored, for example, in the radar sensor 20 or a processing unit 32. The correction parameter 26 is determined before commissioning 12 of the radar sensor system 16 by detecting at least one measurement error M of the measured quantity 22 of an exemplary radar sensor system 36 of the sensor system series 14, which is influenced by a component parameter 34 of the sensor cover 18, in particular by calculation 38, simulation 40 and / or measurement 42, and the correction parameter 26, which can compensate for the measurement error M, is determined and stored uniformly for the entire sensor system series 14 depending on the detected measurement error M of the exemplary radar sensor system 36.

[0053] The component parameter 34 can, for example, be a shape, including a curvature or curvature profile, of the sensor cover 18. The shape of the sensor cover 18 can significantly influence the refraction of radar waves through the sensor cover 18. For example, refraction occurs at the interface between two materials with different permittivity, such as air and the material of the sensor cover 18.R. 416210

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[0055] This results in a measurement error M at, for example, an azimuth angle. <p und / oder einem Elevationswinkel als Messgröße 22 hervorgerufen.

[0056] The exemplary radar sensor system 36 can be a sample or a model of a radar sensor system 16 of the sensor system series 14. The measurement error M can be a variable of the measured quantity 22, for example the azimuth angle. <p, abhängigen Messfehlerverlauf 44 aufweisen. Der Messfehlerverlauf 44 kann ein Verlauf der Winkelabweichung über die Winkelkoordinate 30, insbesondere den Azimuthwinkel <p sein.

[0057] The measurement error M can be determined by measuring several individual measurement errors M', each related to a system parameter 48 of the exemplary radar sensor system 36. The system parameter 48 can be a relative position, for example, a position with respect to an axis 49, of the radar sensor 20 to the sensor cover 18 in the exemplary radar sensor system 36. The system parameter 48 is changed, in particular the radar sensor 20 is moved along the axis 49 relative to the sensor cover 18, and the respective individual measurement error M' is thereby measured across the azimuth angle. <p als einzelner Messfehlerverlauf 50 erfasst.

[0058] Subsequently, a uniform correction value 26 is determined and stored from the several individual measurement errors M' by a calculation 52. The correction value 26 is calculated, for example, by averaging the several individual measurement errors M' and stored in a memory location 54. The correction value 26 is a correction curve 56 over the azimuth angle. <p, wobei der Korrekturverlauf 56 ein Verlauf eines Korrekturwinkels <p c about the azimuth angle <p ist.

[0059] The stored correction parameter 26 can then be transferred to the radar sensor 20 or the computing unit 32 during commissioning 12, in particular during initial commissioning, of the radar sensor system 16 of the sensor system series 14, and can be retrieved there during operation of the radar sensor system 16 in order to calculate the error-compensated measured parameter 28.

[0060] Figure 2 shows a correction curve of a correction parameter of a method for measurement error correction in a further specific embodiment of the invention. The correction curve 56 is shown as the course of the correction angle. <p c via R. 416210

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[0062] Measured quantity, here the angular coordinate, for example the azimuth angle <p, ausgeführt. Die Korrekturwinkel <p c These errors may have been formed by regression of several recorded measurement errors. For an azimuth angle <p von Null kann der Korrekturwinkel <p c The effect should be zero, as this is where the influences from refraction of the radar waves at the sensor cover are minimal.

[0063] Figure 3 shows a measurement error curve and a correction curve of a method for measurement error correction in a further specific embodiment of the invention. The diagram shows the measurement error curve 44 of the measurement error recorded, for example, to determine the correction quantity, in particular the angular deviation of the measured quantity, in comparison to the correction curve 56 and the measurement error 58 remaining after error compensation by applying the correction quantity.

[0064] By applying the correction parameter, here the correction curve 56, during operation of the radar sensor, the remaining measurement error 58 can thus be reduced.

[0065] Figure 4 shows a correction curve of a correction parameter of a method for measurement error correction in a further specific embodiment of the invention. In Figure 4 a), a first individual correction curve 60 is shown as the curve of the correction angle. <p cabout the azimuth angle <p abgebildet. Der Korrekturverlauf 60 wurde aus einem erfassten Messfehler bei einem ersten Systemparameter 48, beispielsweise bei einer ersten Position des Radarsensors 20 relativ zu der Sensorabdeckung 18 berechnet. In Figur 4 b) ist ein zweiter einzelner Korrekturverlauf 62 abgebildet, der aus einem erfassten Messfehler bei einem zweiten Systemparameter 48, beispielsweise bei einer gegenüber der ersten Position entlang der Achse 49 versetzten zweiten Position des Radarsensors 20 relativ zu der Sensorabdeckung 18 berechnet wurde.

[0066] From the first and second individual correction curves 60,62, the uniform correction value can be calculated as a uniform correction curve, for example by averaging.

Claims

R. 416210 - 9 - Patent claims 1. Method for measurement error correction (10) of at least one measured quantity (22) of a radar sensor (20) forming a radar sensor system (16) with a sensor cover (18), comprising Commissioning (12) of the radar sensor system (16) assigned to a sensor system series (14) comprising the radar sensor (20) arranged behind the sensor cover (18), which provides the measured quantity (22) with a measurement error (M) and During operation of the radar sensor system (16), compensation (24) of the measurement error (M) is achieved by retrieving and applying a correction quantity (26) to the measured quantity (22) of the radar sensor (20). characterized by the fact that the correction parameter (26) is a correction parameter (26) that is determined and stored uniformly for the entire sensor system series (14) before commissioning (12) of the radar sensor system (16).

2. Method for measurement error correction (10) according to claim 1, characterized in that the correction quantity (26) is determined before commissioning (12) of the radar sensor system (16) by detecting at least one measurement error (M) of the measured quantity (22) of an exemplary radar sensor system (36) of the sensor system series (14) which is influenced by a component parameter (34) of the sensor cover (18) and by determining and storing the correction quantity (26) that can compensate for the measurement error (M) uniformly for the entire sensor system series (14) depending on the detected measurement error (M) of the exemplary radar sensor system (36).

3. Method for measurement error correction (10) according to claim 1 or 2, characterized in that a single measurement error (M') is detected for each system parameter (48) of the radar sensor system (16) and the correction value (26) is determined and stored depending on the multiple individual measurement errors (M'). R. 416210 - 10 - 4. Method for measurement error correction (10) according to one of the preceding claims, characterized in that the component parameter (34) is a form of the sensor cover (18).

5. Method for measurement error correction (10) according to one of the preceding claims, characterized in that the measured quantity (22) is an angular coordinate (30) and the measurement error (M) is an angular deviation of the angular coordinate (30).

6. Method for measurement error correction (10) according to one of the preceding claims, characterized in that the measurement error (M) has a measurement error profile (44) that depends on the measured quantity (22).

7. Method for measurement error correction (10) according to claims 5 and 6, characterized in that the measurement error profile (44) is a profile of the angular deviation over the angular coordinate (30).

8. Method for measurement error correction (10) according to one of the preceding claims, characterized in that the correction quantity (26) is a correction curve (56) over the measured quantity (22).

9. Method for measurement error correction (10) according to claim 8, characterized in that the correction quantity (26) is a correction angle (p c ) and the correction curve (56) a curve of the correction angle (p c ) about the measured quantity (22).

10. Radar sensor system (16) for detecting at least one measured quantity (22), comprising at least one sensor cover (18) and at least one radar sensor (20) arranged behind the sensor cover (18), which provides the measured quantity (22) which is subject to a measurement error (M) and which can be compensated by a method for measurement error correction (10) according to one of the preceding claims.

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