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

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, especially orthogonally, to the reference direction. The reference direction may be the surface normal of a planar radar sensor. However, the antennas may have offsets, 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 applies to all directions, for example, due to inhomogeneities in the radome. The different times cause a phase shift in the antenna signals of the antennas. The direction can be determined from the phase shift.

[0003] The antenna diagram of a radar sensor can be used to determine direction. The antenna diagram is a measurement of the phase shift and associated channel amplitude. The antenna diagram can show the expected phase shift and channel amplitude for radar signals incident from different directions. The 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, such as a bumper or emblem, the panel may interfere with the reception of the radar signal, causing 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 direction being read from the antenna diagram. [Means for solving the problem]

[0005] Against this background, the proposed approach provides a method for detecting erroneous antenna signals of a radar sensor with multiple antennas, a corresponding control device, and a corresponding computer program product according to the independent claims. Advantageous refinements and improvements of the proposed approach become apparent from this 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 (overtake / backtrack / underpass). 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 signals of one or more transmitting antennas are compared with an antenna diagram corresponding to a previously measured angle. Typically, the antenna diagram is not measured at all azimuth and elevation angle combinations, but rather using only 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 and the antenna diagram best match (correlate). Ageing effects, temperature effects, and hidden installation of sensors behind emblems or bumpers can lead to deviations between the measured antenna diagram and the actual amplitude and phase differences between the transmitting and / or receiving antennas. 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 (too few calibration measurements). These deviations can lead to angular errors and poor correlation values.

[0009] The three effects (aging, temperature, and concealment) are assumed to be static (within a temperature range) or to change only slowly. The correlation value is used, among other things, to detect the overlap of multiple targets within a (d,v) cell and to activate multi-target angle estimation algorithms. Similarly, the correlation value can also be used to detect distortive agnosia, i.e., interference with the ability to measure angles due to coatings on the sensor (ice, snow, mud, 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 tracking.

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

[0011] So far, only the drop in correlation value can be corrected, not the angular error. To calibrate a MIMO radar sensor, the change in the radar sensor's zero point is monitored, and if the deviation is too large, the angular deviation can be corrected by applying a correction factor to the calibration coefficients. Thus, only the global angular offset is calibrated. Local or angle-dependent angular errors have not been taken into account in the calibration so far. [Effects 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 different antennas in the radar sensor is characteristic of the direction to the target. The phase and / or amplitude information for different directions is stored in the radar sensor's antenna diagram. To determine the direction, the phase and / or amplitude information of the antenna signals is searched for similarly to a pattern search of the antenna diagram. The direction is detected where the phase and / or amplitude information of the antenna signal best matches the antenna diagram, i.e., where the correlation between the antenna signal 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 signal. The correlation calculation can be optionally normalized, for example, to the value range [0, 1].

[0014] When there is an error in the antenna signal, the phase and / or amplitude information changes. The changed phase and amplitude information no longer perfectly matches the antenna diagram, 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 scheme presented here, erroneous antenna signals are detected by using antenna signal selection to estimate direction and comparing the resulting correlation with at least one predefined criterion. If the correlation matches the criterion, the antenna signals not used in the selection are detected as erroneous antenna signals. Because there will always be errors in antenna signals due to, for example, thermal noise, the scheme presented here allows for the detection of channels with more errors than other channels.

[0017] The estimation can be performed iteratively by repeating the steps, removing other antenna signals, and checking the resulting correlations against a criterion. Selections whose correlations meet the criterion identify erroneous antenna signals through their 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, wherein 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 for 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 waves. In the case of a radar sensor, the antenna signal may represent echoes of the 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 total set of antenna signals.

[0021] The antennas may be arranged in a defined arrangement relative to one another. 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 represented as a phase shift in 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 entire set. The antenna diagram can represent phase and / or amplitude information of the radar sensor's antenna signal as a function of direction. The antenna diagram can be created, for example, by measuring the radar sensor using a reference transmitter that is movable relative to the radar sensor, particularly with a constant transmission power. The antenna diagram can also 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. Here, the amplitude can characterize the directional characteristics of the radar sensor.

[0023] To estimate direction, phase and / or amplitude information of the antenna signals from the subset can be compared to the antenna diagram, and the removed at least one antenna signal can 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 and the diagram is greatest. The correlation can be expressed as a number, which can be called the correlation value.

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

[0026] The selection condition 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 predetermined tolerance, the subset may be classified as error-free or error-containing.

[0027] Alternatively or additionally, the resulting angles can also be considered, with the error channel causing a highly deviated angle estimate for the subset that includes 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 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 sequentially or in parallel.

[0028] If the correlation values ​​do not satisfy the selection criteria, the estimated correlation values ​​can be compared with each other. The direction 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 may be erroneous to a greater or lesser extent. If the correlation values ​​of all subsets do not satisfy the selection criteria, 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 target can be first determined. Then, the direction estimate using the subset can be limited to a range of directions centered around the rough direction. The rough direction can characterize a range of directions within the antenna diagram. The range of directions can characterize a portion of the antenna diagram. The direction estimate can be more accurate within the range of directions. Because the correlation of the subset is no longer performed for all angular positions in the antenna diagram, the most appropriate subset can be quickly found by the preceding rough estimation.

[0030] The subset may include at least three antenna signals. Multiple 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 centered 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 can be used. In this case, correlation may not be very relevant.

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

[0032] The estimated direction may be used to calculate a correction value for 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 additionally, the antenna diagram. The antenna signal with an error may also be used for correction, since the error sources involved can be corrected by the calculation.

[0033] The antenna diagram vector assigned to the estimated direction can be corrected with the calculated correction value. In this way, angular errors due to phase and / or amplitude errors in 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 slight time offset between the measurements. The determination of the at least one erroneous antenna signal may be ensured by multiple measurements. The multiple measurements may allow detection of randomly occurring interference of the antenna signal.

[0035] A correction value may be calculated for each measurement value. The correction values ​​of the measurement values ​​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 having an error, 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 result in the filtered correction values ​​having 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 that are configured to execute, control or perform the steps of the method variations presented herein in corresponding devices.

[0037] The control device may be an electrical device including 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 in response to 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 sensors and / or as an actuator interface for outputting data and / or control signals to actuators. The communication interface may be configured to read or output data wirelessly and / or via a wired connection. The interface may also be, for example, a software module residing 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 is in particular used for executing, performing and / or controlling the steps of the method according to one of the embodiments described above, when the program product or program is run 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 features of the control devices and methods 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 explanation of the drawings]

[0041] [Figure 1] FIG. 1 is a flow chart of a method according to an embodiment. [Figure 2] 4 is a further flow diagram of a method according to an embodiment. [Figure 3] FIG. 10 is a diagram of a direction estimate according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[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 the object represented by 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 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 the 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 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 corresponds substantially to the method of FIG.

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

[0052] Thereafter, 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, correction 208 with a new angle estimate and time filtering 210 of the correction 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 a target. 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 from the full set has been removed.

[0055] The direction estimate 300 is shown in a diagram showing the direction 112 in degrees on the horizontal axis and the correlation value 114 on the vertical axis. The direction 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 correlation value 114 relative to the antenna diagram. The maximum value indicates the direction 112 estimated using the respective subset of antenna signals. The maximum correlation values ​​114 reached vary in magnitude. 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 largest correlation value 114 is the one that correlates best 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 the maximum correlation value 114 reached, which is 1. If the correlation value 114 reached in this way satisfies the selection criterion 116, the removed antenna signal can still be detected as erroneous.

[0059] Here, the best direction estimate 300 has a maximum correlation value 114 of 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 an error, resulting in a significantly reduced correlation value 114 being 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 shows a significant reduction in the 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 the estimated coarse direction 304 to the target.

[0061] Based on the rough direction 304, a direction range 306 of plus or minus two degrees is defined in the antenna diagram. The direction estimate 300 based on the subset of antenna signals is limited to this direction range 306. Therefore, the direction estimate 300 with the largest correlation value 114 is searched only within this direction range 306. This allows for a reduction in resource consumption when comparing the direction estimate 300 and the correlation value 114.

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

[0063] For this purpose, angle estimation is first performed for all transmit and receive antennas. Suitable targets are 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 without other strong targets within a similar range / velocity cell can be used as a criterion.

[0064] In angle estimation, the antenna diagram, once measured, is correlated with the received signal x of one or more transmitting and / or receiving antennas. The antenna diagram is then converted into a normalized vector as a function of 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 value 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 will 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 or only slightly violated are used for angle determination.

[0073] Therefore, in the second step, multiple angle estimates are performed using different subsets of the transmit and receive antennas. Here, the search is only localized around the angle already calculated in the first step. This avoids ambiguity due to the reduced number of channels in the second step. From the multiple angle estimates, the one that achieves the highest possible correlation value for the selected target without using too few simultaneous channels is selected. In particular, at least three channels are required so that any remaining amplitude and / or phase deviations can be detected based on a drop in correlation value and do not lead to angle errors (with simultaneously high correlation values).

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

[0075] The correction factors determined in this way can be used both to correct the measurement signals and to correct the stored antenna diagrams, and 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 the wavelength) and a target at 0° will be taken as an example. In Figure 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, angular errors will occur and the correlation value will decrease.

[0077] If the calibration factor is determined at 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 comparison with the antenna diagram at 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, the proposed method performs local angle estimation (dashed curve, here ±1.5° of the maximum value determined for all antenna elements) using a different subset of antennas. The estimate with the highest correlation value provides the correct angle at 0°, which is based on the non-violating subset of antennas. Therefore, by comparing the measured signals of all antennas with the stored antenna diagram at the estimated angular positions, 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 uncompromised or only slightly compromised.

[0080] This 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 for successively fewer channels.

[0082] Finally, it should be noted that words 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. 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); A method in which a rough direction (304) to the object is determined using all antenna signals (100) and the antenna diagram (110), and an estimate (300) of the direction (112) using the subset (106) is limited to a range of directions (306) centered on the rough direction (304).

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

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) with the largest correlation value (114) is classified as erroneous.

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

5. 2. The method of claim 1, wherein the object is selected from a group of objects represented in the antenna signals using all antenna signals and at least one object criterion.

6. 2. The method of claim 1, wherein the estimated direction (112) is used to calculate a correction value for the at least one antenna signal (100) classified as having an error, and the correction value is used to correct the at least one antenna signal (100) classified as having an error and / or the antenna diagram (110).

7. The method of claim 1 , wherein the at least one erroneous antenna signal (100) is determined by at least two measurements of the object.

8. Using the estimated direction (112), a correction value for the at least one antenna signal (100) classified as having an error is calculated, and using the correction value, the at least one antenna signal (100) classified as having an error and / or the antenna diagram (110) are corrected; the at least one erroneous antenna signal (100) is determined by at least two measurements of the object; 2. The method of claim 1, wherein a correction value is calculated for each measurement value, the correction values ​​for 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 having an error are corrected using the filtered correction values.

9. A control device configured to execute, perform and / or control the method according to any one of claims 1 to 8 in a corresponding device.

10. A computer program product arranged to instruct a processor, when the computer program product is executed, to execute, perform and / or control a method according to any one of claims 1 to 8.

11. A machine-readable storage medium having stored thereon the computer program of claim 10.

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