Method and control device for detecting erroneous antenna signals of a radar sensor with multiple antennas - Patents.com

Abstract

The present invention relates to a method for detecting erroneous antenna signals (100) of a radar sensor (102) comprising a plurality of antennas (104), wherein a subset (106) of the antenna signals (100) is formed by removing at least one antenna signal (100) from a full set (108) of the antenna signals (100), a direction (112) to an object is estimated using the subset (106) and an antenna diagram (110) of the radar sensor (102), a correlation value (114) between the antenna diagram (110) and the subset (106) of the antenna signals (100) in the estimated direction (112) is determined, and the removed at least one antenna signal (100) for the subset (106) is classified as erroneous if the correlation value (114) satisfies a selection condition (116).

Description

[Technical field]

[0001] The present invention relates to a method for detecting erroneous antenna signals of a radar sensor with multiple antennas, a corresponding control device and a corresponding computer program product. [Background technology]

[0002] A radar sensor may have multiple antennas and a reference direction. The antennas may be oriented, for example, transversely, in particular orthogonally, to the reference direction. The reference direction may be the surface normal of a planar radar sensor. However, the antennas may have an offset, for example on a curved surface. If a radar signal strikes the radar sensor from a direction other than the reference direction, the wavefront of the radar signal strikes the antenna at different times. Strictly speaking, this is true for all directions, e.g. due to inhomogeneities in the radome. The different times cause a phase shift in the antenna signals of the antennas. From the phase shift the direction can be determined.

[0003] The antenna diagram of a radar sensor can be used to determine direction. An antenna diagram is a measurement of the phase shift and associated channel amplitude. An antenna diagram can show the expected phase shift and channel amplitude for radar signals incident from different directions. An antenna diagram can be created, for example, by measuring the radar sensor with a reference antenna, a retroreflector, and a target generator. Summary of the Invention [Problem to be solved by the invention]

[0004] If the radar sensor is installed behind a panel, for example a bumper or emblem, the panel may block the reception of the radar signal, resulting in errors in the antenna signal. In particular, the antenna signal may have a phase shift due to the panel. This phase shift may distort the resulting phase shift in its direction. An erroneous antenna signal may result in an incorrect reading of the direction from the antenna diagram. [Means for solving the problem]

[0005] Against this background, a method for detecting erroneous antenna signals of a radar sensor with multiple antennas, a corresponding control device and a corresponding computer program product are proposed according to the presently presented approach according to the independent claims. Advantageous refinements and improvements of the presently presented approach become apparent from the description and are set forth in the dependent claims.

[0006] In addition to distance and relative speed, azimuth and elevation angles are very important for monitoring the environment in driver assistance systems, as they allow lanes to be assigned and statements about the relevance of targets to be made (can overtake / can go wrong way / can slip through). The azimuth and elevation angles of a target can be calculated from the amplitude and / or phase differences of the transmitting and / or receiving antennas of an antenna array.

[0007] During angle estimation, the received signal of one or more transmitting antennas is compared with an antenna diagram corresponding to previously measured angles. Typically, the antenna diagram is not measured at all azimuth and elevation angle combinations, but only using two sections (e.g., an azimuth section at elevation=0° and an elevation section at azimuth=0°). Alternatively, the antenna diagram may be generated from an ideal antenna diagram using one or a few calibration measurements at individual angular positions.

[0008] If there is only one target in the (d,v) cell, the estimated angle is the position where the received signal best matches (correlates) with the antenna diagram. Ageing effects, temperature effects and hidden installation of sensors behind emblems or bumpers can lead to deviations between the measured antenna diagram and the amplitude and phase differences between the transmitting and / or receiving antennas that actually occur. Such deviations can in principle also be caused by sensor misalignment (e.g. elevation misalignment: several targets have elevation angles that deviate significantly from the azimuth calibration) or by incomplete calibration (low number of calibration measurements). These deviations can lead to angular errors and poor correlation values.

[0009] Three effects (aging, temperature, and concealment) are assumed to be static (within a certain temperature range) or to change only slowly. The correlation value is used in particular to detect the overlap of multiple targets in a (d,v) cell and to activate multi-target angle estimation algorithms. Similarly, the correlation value can be used to detect distortive agnosia, i.e. the interference of the angle measurement capability with coatings on the sensor (ice, snow, slush, etc.). Furthermore, the correlation value can be used as a quality criterion for the reliability of the estimates and as an important criterion for object formation (tracking).

[0010] Therefore, the decrease in correlation value due to the above-mentioned effect increases the malfunction of multi-target angle estimation algorithms (ghost targets with large angle errors of multiple degrees) on the one hand, and increases the false positives of distortive agnosia on the other hand. Also, the decrease in correlation value may hinder object formation.

[0011] So far, only the drop in correlation values ​​can be corrected, not the angular errors. To calibrate a MIMO radar sensor, the change in the zero point of the radar sensor is monitored, and if the deviation is too large, the angular deviation can be corrected by applying a correction factor to the calibration coefficient. Thus, only the global angular offset is calibrated. Local or angle-dependent angular errors could not be taken into account in the calibration so far. Effect of the Invention

[0012] In addition to correcting for correlation degradation, the scheme presented here allows for direct correction of global and local angular errors in determining the calibration coefficients, as long as the amplitude and phase errors for a subset of the transmit and receive antennas are less significant than for the remaining antennas.

[0013] The phase and / or amplitude information of the antenna signals of the different antennas of the radar sensor is characteristic for the direction to the object. The phase and / or amplitude information for the different directions is stored in the antenna diagram of the radar sensor. To determine the direction, the phase and / or amplitude information of the antenna signals is searched for similar to a pattern search in the antenna diagram. The direction is detected where the phase and / or amplitude information of the antenna signals best matches the antenna diagram, i.e., where the correlation between the antenna signals and the antenna diagram reaches a maximum value. Here, the correlation can reach a maximum value if the phase and / or amplitude information perfectly matches the antenna diagram. The lower the correlation value, the less the match between the antenna diagram and the antenna signals. The correlation calculation can be arbitrarily normalized, for example in the value range [0,1].

[0014] If there is an error in the antenna signal, the phase and / or amplitude information changes. The changed phase and amplitude information no longer matches the antenna diagram perfectly, but resembles it. The correlation between the antenna signal and the antenna diagram decreases due to the error, and the pattern search systematically produces errors.

[0015] Here, the fact that not all antenna signals are equally erroneous is exploited: if highly erroneous antenna signals are not used for direction estimation, better correlation and therefore better estimation can be achieved.

[0016] In the presented scheme, erroneous antenna signals are detected by using a selection of antenna signals to estimate the direction and comparing the obtained correlation with at least one predefined criterion. If the correlation matches the criterion, the antenna signals not used for the selection are detected as erroneous antenna signals. Since there are always errors in antenna signals, for example due to thermal noise, the presented scheme allows to detect channels with more errors than other channels.

[0017] The estimation can be performed iteratively by repeating the steps, removing the other antenna signals and checking the resulting correlations against a criterion: a selection whose correlation satisfies the criterion identifies an antenna signal with an error over its non-selection.

[0018] According to one aspect of the present invention, a method is proposed for detecting erroneous antenna signals of a radar sensor comprising multiple antennas, where a subset of antenna signals is formed by removing at least one antenna signal from the full set of antenna signals, a direction to an object is estimated using the subset and an antenna diagram of the radar sensor, a correlation value between the antenna diagram and the subset of antenna signals in the estimated direction is determined, and if the correlation value satisfies a selection condition, the at least one removed antenna signal for the subset is classified as erroneous.

[0019] The ideas regarding the embodiments of the present invention can be considered to be based, inter alia, on the ideas and findings described below. The antenna signal may be an electrical signal. The antenna signal may represent electromagnetic waves received by an associated antenna or properties, such as phase and / or amplitude information, that characterize such electromagnetic waves. In the case of a radar sensor, the antenna signal may represent echoes of an emitted radar signal.

[0020] The radar sensor may have multiple antennas, in particular more than two, more than three or more than four antennas. The antennas may be transmitting and / or receiving antennas. The antennas may be spatially separated from each other. All antennas may represent the same echo in their respective antenna signals. All antenna signals together form a full set of antenna signals.

[0021] The antennas may be arranged in a defined arrangement relative to each other. For example, the antennas may be arranged at distances corresponding to fractions and / or multiples of the wavelength of the radar signal. This arrangement allows the echoes to arrive at the antennas at different times. The different times may be expressed as a phase shift of the antenna signals. Thus, the antenna signals may have different phase positions. The phase shift or phase position of the antenna signals varies depending on the direction from which the echoes are received. The antenna signals may also have different amplitudes depending on the direction.

[0022] The subset may be a selection of antenna signals. The subset may include at least one antenna signal that is less than the full set. The antenna diagram can represent phase and / or amplitude information of the antenna signal of the radar sensor as a function of direction. The antenna diagram can be created, for example, by measuring the radar sensor with a reference transmitter that is movable relative to the radar sensor, in particular with a constant transmission power. The antenna diagram may be derived from analytical calculations. The antenna diagram can represent the phase shift of the antenna signal across directions. The antenna diagram can also represent the amplitude of the antenna signal across directions, where the amplitude can characterize the directional characteristics of the radar sensor.

[0023] To estimate a direction, phase and / or amplitude information of the antenna signals from the subset may be compared to the antenna diagram, and the at least one removed antenna signal may be ignored in the comparison.

[0024] The direction can be found where the phase and / or amplitude information of the antenna signal best matches the antenna diagram, or where the correlation between the antenna diagram and the signal is greatest. The correlation can be expressed as a number. The number can be called the correlation value.

[0025] The selection criterion may be a minimum value of the correlation value. For example, the antenna signals of the subset with a correlation value greater than 0.95 may be classified as nearly error-free, while at least one of the removed antenna signals is classified as errored. The direction to the object estimated for this subset may be output as an angle to the object. The selection criterion is typically preset.

[0026] The selection criterion may depend on the signal-to-noise ratio of the antenna signals, which may be referred to as the signal-to-noise ratio (SNR). In particular, the antenna signals of a subset can be classified as error-free if the achieved correlation value is 1 or a perfect match is found. Taking into account a predefined tolerance, the subset may be classified as error-free or error-containing.

[0027] Alternatively or supplementarily, the resulting angles can also be considered, with the error channel causing a highly deviated angle estimate for the subset that contains it. If the correlation value does not satisfy the selection condition, a further subset can be formed from the total set by removing at least one other antenna signal from the total set. This can be done in a further method step within the scope of the iterative configuration of the method described herein. Using the further subset and the antenna diagram, a further direction to the object can be estimated and a further correlation value of the further subset of antenna signals with the antenna diagram in the estimated further direction can be determined. If the further correlation value satisfies the selection condition, the other at least one antenna signal removed for the further subset can be classified as erroneous. If the further correlation value satisfies the selection condition, the further estimated direction can be selected as the angle to the object. If the correlation value does not satisfy the selection condition, the search can be continued until the correlation value satisfies the selection condition. In this way, multiple different subsets can be tried in succession or in parallel.

[0028] If the correlation values ​​do not satisfy the selection condition, the estimated correlation values ​​can be compared with each other. The orientation of the subset with the largest correlation value can be selected as the angle to the object. At least one antenna signal removed in this estimation can be classified as erroneous. Multiple antenna signals can be more or less erroneous. If the correlation values ​​of all subsets do not satisfy the selection condition, the most correlated subset can be selected to find at least one erroneous antenna signal.

[0029] Using all antenna signals and the antenna diagram, a rough direction to the object can first be determined. Then, the direction estimate using the subset can be limited to a direction range centered around the rough direction. The rough direction can characterize a direction range in the antenna diagram. The direction range can characterize a portion of the antenna diagram. The direction estimate can be more accurate within the direction range. Since the correlation of the subset is no longer performed for all angular positions of the antenna diagram, the most suitable subset can be found quickly by the preceding rough estimation.

[0030] The subset may include at least three antenna signals. A plurality of estimated correlation values ​​may be compared from more than two antenna signals. A rough direction to the object may be read. The direction estimate using the subset may be limited to a range of directions around the rough direction. The subset may include at least two of the antenna signals. The rough direction may be read by another sensor. If the rough direction is known, the subset whose direction best matches the rough direction may be used. Correlation may then be less relevant.

[0031] An object may be selected from a group of objects represented in the antenna signals using all antenna signals and at least one object criterion. The object may be searched and found in a detection area of ​​the radar sensor using all antenna signals. One of these objects may be selected for detecting at least one erroneous antenna signal. The object may be set in a rough direction. For the deviated rough direction, the at least one erroneous antenna signal may be searched for with a different object in the deviated rough direction. The search may be performed in other rough directions at different times.

[0032] The estimated direction may be used to calculate a correction value for the at least one antenna signal classified as having an error. The correction value may be used to correct the at least one antenna signal classified as having an error and, alternatively or supplementarily, the antenna diagram. The erroneous antenna signal may also be used by correction, since the error sources involved can be corrected by calculation.

[0033] The antenna diagram vector assigned to the estimated direction can be corrected with the calculated correction value. In this way, the angular error due to the phase error and / or amplitude error of the error channel can be corrected in the current and / or future measurement cycles.

[0034] The at least one erroneous antenna signal may be determined by at least two measurements of the object. The measurements may be detected alternately in time. In particular, consecutive measurements may be used. The measurements may differ slightly due to a small time shift between the measurements. The determination of the at least one erroneous antenna signal may be ensured by multiple measurements. The multiple measurements may allow randomly occurring interference of the antenna signal to be detected.

[0035] A correction value may be calculated for each measurement value. The correction values ​​of the measurements may be filtered over time to obtain filtered correction values. The filtered correction values ​​may be used to correct at least one antenna signal classified as erroneous and, alternatively or supplementarily, the antenna diagram. Filtering may reduce fluctuations in the filtered correction values. Filtering may remove outliers in the correction values. Filtering may cause the filtered correction values ​​to have a smoothed curve.

[0036] The method may be implemented, for example, in software or hardware, or a mixture of software and hardware, for example in a controller. The methods presented herein also create control devices configured to execute, control or perform the steps of the method variations presented herein in corresponding devices.

[0037] The control device may be an electric device with at least one computing unit for processing signals or data, at least one memory unit for storing signals or data, and at least one interface and / or communication interface for reading or outputting data embedded in a communication protocol. The computing unit may be, for example, a signal processor, a so-called system ASIC or a microcontroller for processing sensor signals and outputting data signals depending on the sensor signals. The memory unit may be, for example, a flash memory, an EPROM or a magnetic memory unit. The interface may be configured as a sensor interface for reading sensor signals from a sensor and / or as an actuator interface for outputting data and / or control signals to an actuator. The communication interface may be configured to read or output data wirelessly and / or wired. The interface may also be a software module present, for example, on a microcontroller together with other software modules.

[0038] A computer program product or computer program having a program code is also advantageous, which may be stored on a machine-readable carrier or storage medium, such as a semiconductor memory, a hard disk memory or an optical memory, and in particular is used to execute, perform and / or control the steps of the method according to one of the embodiments described above, when the program product or program is executed on a computer or device.

[0039] It should be noted that some of the possible features and advantages of the present invention are described herein in relation to different embodiments, and those skilled in the art will recognize that the features of the control device and method can be suitably mixed, matched, or interchanged to arrive at further embodiments of the present invention.

[0040] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings, but neither the drawings nor the description should be construed as limiting the present invention. [Brief description of the drawings]

[0041] [Figure 1] FIG. 2 is a flow chart of a method according to an embodiment. [Diagram 2] FIG. 4 is a further flow diagram of a method according to an embodiment. [Diagram 3] FIG. 11 is a diagram of a direction estimate according to an embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0042] The figures are only schematic and are not to scale. Identical reference signs indicate identical or similarly acting features. 1 is a flow diagram of an example method for detecting corrupted antenna signals 100 of a radar sensor 102 having multiple antennas 104. A subset 106 of antenna signals 100 is formed from a full set 108 of antenna signals 100 by removing at least one antenna signal 100 of the full set 108.

[0043] Using the subset 106 and an antenna diagram 110 of the radar sensor 102, a direction 112 to an object represented in the antenna signal 100 is estimated, and a correlation value 114 between the subset 106 of the antenna signal 100 in the estimated direction 112 and the antenna diagram 110 is determined.

[0044] The correlation value 114 is compared to a selection condition 116. If the correlation value 114 satisfies the selection condition 116, the antenna signal 100 that was removed in forming the subset 106 is classified as an antenna signal 100 with error.

[0045] If the correlation value 114 satisfies a selection condition 116, the estimated direction 112 may be selected as the angle 118 to the object. In an embodiment, if the correlation value 114 does not satisfy the selection condition 116, at least one further subset 106 is formed. In the further subset 106, at least one other antenna signal 100 of the total set 108 is removed.

[0046] A further direction 112 to the object is then estimated using the further subset 106 and a further correlation value 114 of the further subset 106 of the antenna signals 100 with the antenna diagram 110 in the further estimated direction 112 is determined.

[0047] The further correlation value 114 is compared to a selection condition 116 and if the further correlation value 114 satisfies the selection condition 116 then the antenna signal 100 that was removed in forming the further subset 106 is classified as an erroneous antenna signal 100 .

[0048] In an embodiment, this process is repeated until a subset 106 of antenna signals 100 is found whose correlation values ​​114 satisfy a selection condition 116. At this point, multiple antenna signals 100 from the total set 108 may be removed.

[0049] In one embodiment, the correlation values ​​114 of the different subsets 106 are compared with each other. The selection criterion 116 is the highest correlation value 114 reached. At least one antenna signal 100 removed from the subset 106 with the highest correlation value 114 is classified as an erroneous antenna signal 100.

[0050] The direction 112 estimated using the subset 106 with the largest correlation value 114 may be selected as the angle 118 to the object. 2 is a further flow diagram of a method according to an embodiment, which roughly corresponds to the method of FIG.

[0051] Furthermore, the selection of the subset 200 is preceded by an angle estimation 202 with all transmit and receive antennas of the radar sensor, followed by a selection 204 of at least one target suitable for calibration, the target corresponding to the object of FIG.

[0052] Then, a selection 200 of a subset of transmit and receive antennas is performed and a local angle estimation 206 is performed. If the maximum correlation value reached is high enough, a correction 208 with a new angle estimate and a time filtering 210 of the corrections is performed.

[0053] If the maximum correlation value reached is not high enough, the selection 200 and angle estimation 206 are performed again. The correction values ​​are used to correct 212 the measured signals or to correct 214 the stored antenna diagrams.

[0054] 3 is a diagram of direction estimates 300 for an object. The direction estimates 300 are, for example, estimates from FIG. 1 and are based on different subsets of antenna signals. For each direction estimate 300, at least one of the antenna signals of the full set has been removed.

[0055] The orientation estimate 300 is shown in a diagram showing the orientation 112 in degrees on the horizontal axis and the correlation value 114 on the vertical axis. The orientation 112 is shown here as a positive or negative deviation from an absolute angle 118 relative to the object, and the correlation value 114 has been normalized to a value range from zero to one.

[0056] The direction estimates 300 are shown as curves of correlation values ​​114 across directions 112. Each direction estimate 300 has a maximum of correlation values ​​114 relative to the antenna diagram. The maximum indicates the direction 112 estimated using the respective subset of antenna signals. The maximum correlation values ​​114 reached are of different magnitudes. The more accurately each direction estimate 300 matches the antenna diagram, the larger its correlation value 114 will be.

[0057] The direction estimate 300 that reaches the highest correlation value 114 is the best correlated with the antenna diagram. The subset of antenna signals used for this direction estimate 300 is assumed to be the subset with the smallest phase / amplitude errors. Therefore, at least one antenna signal removed in this subset has a high probability of being erroneous and can be characterized as erroneous.

[0058] If the antenna signals included in this subset are slightly erroneous, the correlation value 114 will be slightly reduced compared to 1, the maximum correlation value 114 reached. If the correlation value 114 thus reached satisfies the selection criterion 116, the removed antenna signal can still be detected as erroneous.

[0059] Here, the maximum correlation value 114 of the best direction estimate 300 is 1. Therefore, the antenna signals used for this direction estimate 300 have the smallest phase / amplitude errors. For all other direction estimates 300, the subsets used each contain at least one antenna signal with error, resulting in a significantly reduced correlation value 114 reached.

[0060] In one embodiment, the figure also shows a coarse estimate 302 from the full set of antenna signals. For the coarse estimate 302, a curve of correlation value 114 across directions 112 is also shown. The coarse estimate 302 has a significantly reduced maximum correlation value 114 for the antenna diagram due to the use of at least one antenna signal with error. The maximum value of the coarse estimate 302 characterizes an estimated coarse direction 304 to the object.

[0061] Based on the rough direction 304, a direction range 306, here ±2 degrees, is defined in the antenna diagram. The direction estimate 300 based on a subset of the antenna signals is limited to this direction range 306. Therefore, the direction estimate 300 with the maximum correlation value 114 is searched only within this direction range 306. This allows the comparison of the direction estimate 300 and the correlation value 114 to reduce resource consumption.

[0062] In an embodiment, the direction 112 to the object defined by the maximum of the correlation value 114 is defined as an angle 118 to the object. In other words, an on-line calibration of antenna diagrams by subarray evaluation is presented.

[0063] For this, first an angle estimation is performed for all transmit and receive antennas. A suitable target is selected based on various criteria. In particular, a sufficiently high SNR (signal-to-noise ratio) can be a criterion. Another criterion is a single target or a sufficiently small deviation from the signal model of a single target. Similarly, an isolated target, with no other strong targets present within a similar range / speed cell, can be used as a criterion.

[0064] In angle estimation, the antenna diagram, once measured, is correlated with the received signals x of one or more transmitting and / or receiving antennas. The antenna diagram is then converted into a normalized vector depending on the angle

[0065]

number

[0066] The received signal for the target is also expressed as a normalized vector

[0067]

number

[0068] Mathematically, we use the function q to estimate the target angle. 2 (θ) is maximized. The result of the maximum search

[0069]

number

[0070] is the estimated target angle.

[0071]

number

[0072] Due to amplitude and phase deviations, the estimated angle of the selected target does not match the actual angle. This deviation (bias) can be avoided or at least reduced if only transmit and receive antennas whose relative phase is not violated or only slightly violated are used for the angle determination.

[0073] Therefore, in a second step, multiple angle estimates are performed using different subsets of transmit and receive antennas. Here, the search is only locally around the angle already calculated in the first step. This allows to avoid ambiguities due to the reduction in the number of channels in the second step. From the multiple angle estimates, the one that reaches the highest possible correlation value for the selected target and does not use too few channels at the same time is selected. In particular, at least three channels are required so that remaining amplitude and / or phase deviations can be detected based on a drop in the correlation value and do not lead to angle errors (with a high correlation value at the same time).

[0074] In this way, an angle estimate is selected such that the channel used is violated as little as possible. The correlation drop is then corrected with the improved angle estimate, thereby achieving a perfect calibration, i.e., both the angle error correction and the correlation drop correction.

[0075] The correction factors determined in this way can be used both for correcting the measurement signals and for correcting the stored antenna diagrams, whereby it is advantageous to correct the antenna diagrams if the correction factors are determined as a function of the angle.

[0076] In the method presented here, an antenna array with a position of [0;0.5;2;3;5]λ (λ is wavelength) and a target at 0° is taken as an example. In Fig. 3, for example, the phase error of the antenna at position 5λ is 80°, i.e., the phase error vector does not depend on the angle [0°0°0°0°80°]. If estimation is performed for all antenna elements, an angle error occurs and the correlation value decreases.

[0077] If we determine the calibration factor with the estimated angles for all antenna elements, the result is [0°-7°-27°-41°11°]. This deviation from the actual phase error is due to the comparison with the antenna diagram at the angular positions with errors.

[0078] When correction is performed using these coefficients, the decrease in correlation value is corrected, but the angle error is not corrected. In contrast, in the scheme presented here, a local angle estimation (dashed curve, here ±1.5° of the maximum value determined for all antenna elements) is performed using a different subset of antennas. The estimate with the maximum correlation value provides the correct angle at 0°, which is based on the non-violating subset of antennas. Thus, by comparing the measured signals of all antennas with the stored antenna diagram at the angular positions thus estimated, the correct amplitude and phase errors can be determined.

[0079] This principle can also be used when one or more antennas are subject to amplitude and / or phase errors. Local estimation requires at least three channels that are not or only slightly compromised.

[0080] The method can also be applied to MIMO arrays with multiple transmit and receive antennas, where it is advantageous to consider the channel cancellation of the transmit and receive arrays rather than the virtual array, which significantly reduces the number of configurations or subsets of the virtual array to be examined.

[0081] The optimal subset of transmit and receive antennas can be calculated over all possible subsets with more than three virtual channels, or it can be calculated successively for fewer and fewer channels.

[0082] Finally, it should be noted that terms such as "comprise" and "include" do not exclude other elements or steps, and that indefinite articles such as "eine" or "ein" do not exclude a plurality. Reference signs in the claims are not to be regarded as limitations.

Claims

1. 1. A method for detecting erroneous antenna signals (100) of a radar sensor (102) having a plurality of antennas (104), comprising: forming a subset (106) of the antenna signals (100) by removing at least one antenna signal (100) from a full set (108) of the antenna signals (100); estimating a direction (112) to an object using the subset (106) and an antenna diagram (110) of the radar sensor (102); determining a correlation value (114) between the antenna diagram (110) and the subset (106) of the antenna signals (100) in the estimated direction (112); and classifying the removed at least one antenna signal (100) for the subset (106) as erroneous if the correlation value (114) satisfies a selection condition (116).

2. 2. The method of claim 1 , further comprising forming a further subset (106) from the total set (108) by removing at least one other antenna signal (100) from the total set (108) if the correlation value (114) does not satisfy the selection condition (116), estimating a further direction (112) to the object using the further subset (106) and the antenna diagram (110), determining a further correlation value (114) of the further subset (106) of the antenna signals (100) with the antenna diagram (110) in the estimated further direction (112), and classifying the removed at least one other antenna signal (100) for the further subset (106) as erroneous if the further correlation value (114) satisfies the selection condition (116).

3. 3. The method of claim 2, wherein if the correlation values ​​(114) do not satisfy the selection condition (116), the correlation values ​​(114) are compared with each other and the removed at least one antenna signal (100) for the subset (106) for which the correlation value (114) is greatest is classified as erroneous.

4. 4. The method of claim 1, wherein a rough direction (304) to the object is determined using all antenna signals (100) and the antenna diagram (110), and the estimate (300) of the direction (112) using the subset (106) is limited to a range of directions (306) centered on the rough direction (304).

5. The method of claim 1 , wherein the subset (106) comprises at least three antenna signals (100).

6. 4. The method of claim 1, wherein a rough direction (304) to the object is read, and the estimate (300) of the direction (112) using the subset (106) is limited to a range of directions (306) centered on the rough direction (304), the subset (106) including at least two of the antenna signals (100).

7. The method according to any one of claims 1 to 6, wherein the object is selected from a group of objects represented in the antenna signals (100) using all the antenna signals (100) and at least one object criterion.

8. 8. The method according to claim 1, further comprising calculating a correction value for the at least one antenna signal (100) classified as having an error using the estimated direction (112) and correcting the at least one antenna signal (100) classified as having an error and / or the antenna diagram (110) using the correction value.

9. The method according to any one of claims 1 to 8, wherein the at least one erroneous antenna signal (100) is determined by at least two measurements of the object.

10. 10. The method according to claim 8 and 9, wherein a correction value is calculated for each measurement value, the correction values ​​of the measurements are filtered over time to obtain filtered correction values, and the at least one antenna signal (100) and / or the antenna diagram (110) classified as erroneous are corrected using the filtered correction values.

11. A control device configured to execute, perform and / or control the method according to any one of claims 1 to 10 in a corresponding device.

12. A computer program product arranged to instruct a processor, when executed, to execute, perform and / or control a method according to any one of claims 1 to 10.

13. 13. A machine-readable storage medium having stored thereon the computer program product of claim 12.

Images