Method for determining angle information

Abstract

The present invention relates to a method for determining angle information (200) about the direction of a target object (5) in a radar system (2) for a vehicle (1), wherein the following steps are performed: - providing first detection information (201) of a first modulation mode (251) of the radar system (2), - providing at least one second detection information (202) of at least one second modulation mode (252) of the radar system (2), - combining the detection information (201, 202) of different modulation modes (251, 252) so as to perform the determination of angle information (200) based on the combined detection information (201, 202).

Description

Technical Field

[0001] This invention relates to a method for determining angle information. This invention also relates to a radar system for determining angle information. Background Technology

[0002] As is known from existing technology, radar systems in vehicles are used to provide driver assistance systems, such as automatic distance adjustment or automatic lane change assistance. Here, radar signals emitted by the radar system can be reflected, received, and evaluated by target objects in the vehicle's surrounding environment to perform object detection. Object detection includes, for example, determining the distance and relative speed of the target object. For this purpose, a continuous wave radar device can be used as the radar system, wherein the emitted radar signal is designed to be frequency modulated. Furthermore, in multi-mode radar, more than one modulation mechanism can be employed, and therefore different radar signals with different modulation modes can be emitted. In this way, the measurement quality of the radar system can be improved.

[0003] Document US20180321368A1 discloses a multimode radar that emits radar signals with different modulation modes.

[0004] However, a frequent drawback is that target detection can still be too unreliable or erroneous in certain situations. Therefore, one object of the present invention is to at least partially eliminate these disadvantages. In particular, an object of the present invention is to provide an improved solution for operating multi-mode radar. Summary of the Invention

[0005] The aforementioned objective is achieved by a method having the features of claim 1 and a radar system having the features of claim 14. Further features and details of the invention are derived from the corresponding dependent claims, the description, and the drawings. The features and details described herein in conjunction with the method according to the invention naturally also apply to the radar system according to the invention, and vice versa, so that disclosures regarding various aspects of the invention can always be cross-referenced.

[0006] This objective is achieved, in particular, by a method for determining angular information about the direction of a target object in a radar system, especially for vehicles. The vehicle is, for example, a bus or truck, and has at least one driver assistance system. This angular information can be used to provide at least one function for the driver assistance system. In other words, the radar system can be functionally integrated into the driver assistance system. The driver assistance system is, for example, configured as an automatic lane-keeping assist or a distance adjuster.

[0007] In the method according to the invention, the following steps may be performed, preferably in a given order or in any order, wherein individual and / or all steps may be repeated.

[0008] - Provides first detection information for a first modulation mode of the radar system, wherein the first detection information is generated specifically from a received radar signal modulated according to the first modulation mode.

[0009] - Provide at least one second detection information (i.e., possibly third and / or fourth detection information, etc.) for at least one second modulation mode (i.e., possibly third and / or fourth modulation mode, etc.) of a radar system, wherein the second detection information is generated in particular from a received radar signal modulated according to the second modulation mode, and preferably additional detection information is generated from a received radar signal modulated according to another modulation mode.

[0010] - Combine detection information from different modulation modes to determine angle information based on the combined detection information.

[0011] Traditional methods determine angle information based solely on detection information for a single modulation mode. Therefore, compared to conventional solutions, this invention offers the advantage of combining measurements used for different modulation modes. The combination of detection information, particularly in an additive form, leads to an improvement in SNR and thus an improved angle estimation. Depending on the number of different modulation modes, in the method according to the invention, in addition to the first and second detection information, further (third, fourth, etc.) detection information for the corresponding (third, fourth, etc.) modulation modes can be provided. Angle information can then be determined in a particularly reliable manner based on the combined detection information, for example, through digital beamforming.

[0012] Angular information advantageously refers to the angle of the radar signal at the antenna of the radar system, particularly the exit angle and / or incident angle. Based on this angle, the orientation of the target object relative to the radar system can be determined accordingly. For this purpose, multiple antennas of the radar sensor of the radar system can be used, i.e., transmitting and / or receiving antennas. It is conceivable, for example, to use 2 to 20, preferably 4 to 16, and more preferably 8 to 12 different antennas. Depending on the angle, the spatial distance between the antennas results in a difference in the transit time of the radar signal transmitted or received by the antennas. For each antenna and for each target object on which the radar signal is reflected, its own sub-signal can be derived from the detection information. For this purpose, for example, the received radar signal is digitized, subjected to at least one Fourier transform to obtain the detection information in spectral form, and peak identification is performed therein. This will be described in more detail below.

[0013] As mentioned above, a radar system's radar sensor can have multiple antennas. By using multiple receiving and / or transmitting antennas, for example, according to a MIMO transmission mechanism, the orientation of a target object can be detected in this way. For this purpose, the exit angle and / or incident angle of the transmitted or received radar signal can be evaluated. Sufficient angle measurement capability is a crucial prerequisite here, especially when used with current driver assistance systems. Angle measurement capability is significantly affected by the parameters: antenna aperture and SNR (Signal-to-noise ratio). Here, aperture represents the maximum distance between the two antennas of the radar sensor and is proportional to the angle measurement capability. The same behavior applies to the target object's SNR.

[0014] To obtain one of the detection information, a radar system can first transmit a radar signal via at least one transmitting antenna according to one of the modulation modes. The radar signal includes, for example, multiple sequentially output frequency ramps (hereinafter also referred to as chirps). Each chirp can be frequency modulated separately and therefore has a varying frequency. Linear frequency modulation is used here, for example, where the frequency varies linearly within a predetermined bandwidth in the respective chirp.

[0015] Furthermore, more than one radar signal can be transmitted through at least one transmitting antenna, depending on different modulation modes. For easier understanding, only two modulation modes are discussed below; additional modulation modes may also be provided. Different chirped signals are used in such multi-mode operation. Therefore, radar signals with different modulation modes differ in terms of chirp modulation. Specifically, the bandwidth and / or duration T1 or T2 and / or chirped distance and / or center frequency of each chirp in the radar signals of different modulation modes can be different. This affects the measurement quality of the radar system, for example, influencing the measurement range and / or range resolution and / or the relative velocity of the target object. For example, two to five different modulation modes can be used.

[0016] A radar signal reflected from at least one target object and delayed by a corresponding signal transit time can be detected as a received signal by at least one receiving antenna of a radar system. Having a frequency f b =f s -f e The baseband signal can be obtained from the corresponding received signal. Here, f s It is the frequency of the emitted radar signal, f. e It is the frequency of the received signal. Frequency f bThe signal transit time τ depends on the signal transit time and therefore on the distance R from the target. If multiple antennas (i.e., transmitting and / or receiving antennas) are used, multiple radar signals reflected from the same target can be received simultaneously or sequentially as received signals. Their signal transit times τ also differ slightly from each other. This difference can be evaluated based on the phase of the received signals to determine angular information.

[0017] To perform detection of at least one target object, detection information can be determined based on the received signal, and particularly on the baseband signal. For example, the detection information is generated from a digitized baseband signal or from analysis of at least one frequency of the baseband signal. Accordingly, the detection information can be digital information, i.e., data values. If N chimes are output in a radar signal, the duration of the corresponding chimes is T1 / N. After duration T1, the processing of the detection information can be performed within duration T2-T1. The entire measurement cycle therefore has a duration T2.

[0018] Individual values ​​of the received signal can be detected during duration T1, thus forming detection information from the detected values ​​and possible preprocessing (e.g., down-mixing and / or analog-to-digital conversion and / or at least one Fourier transform). The detected values ​​can be interpreted as a matrix where the individual values ​​are sequentially stored in a two-dimensional manner in an MxN matrix with M samples and N chirps per chirp until the end of duration T1. The first dimension can be specifically used for the distance to the target object, and the other (second) dimension is specifically used for the Doppler frequency and therefore for the relative velocity of the target object. Based on this matrix, at least one spectrum can then be obtained by at least one Fourier transform of the matrix, thereby determining the relative velocity and / or distance of at least one target object in the vehicle's surrounding environment. Specifically, the spectrum can be obtained from a (e.g., column-by-column) first Fourier transform of the matrix in the first dimension direction, which is then recombined into a two-dimensional matrix, from which the distance can be obtained. The relative velocity can then also be obtained from a (row-by-row) second Fourier transform in the second dimension direction of the spectrum. If multiple transmit and / or receive antennas are used, the third dimension can also be used for the received signals from different transmit and / or receive antennas. In this case, after the second Fourier transform, there are multiple spectra for different antennas. The result of the second Fourier transform can therefore be a three-dimensional matrix, which can also correspond to the detection information. However, here it is only data generated from the received signal of a single modulation mode. Another Fourier transform in this third dimension can be used to determine the angle and thus the orientation of the target object. Traditionally, this angle determination is performed only based on the detection information of a single modulation mode.

[0019] However, in this invention, it is advantageous to first perform a combination of additional detection information for a different modulation mode. Then, one possibility for determining angular information from the combined detection information is to perform a third Fourier transform in the third dimension. The result of this third Fourier transform can correspond to angular information, such as the so-called beamforming (BF) spectrum. The third Fourier transform is performed, for example, at the location where the combined detection information detects the target object, i.e., within a bin. For this purpose, peak identification (peak detection) is performed, for example, in the combined detection information.

[0020] Within the scope of this invention, it can be advantageously specified that the first and at least one second detection information (and particularly the third detection information, etc.) each have at least two sub-signals. Each individual detection information can therefore have a corresponding at least two sub-signals. These at least two sub-signals can be specifically used for at least two radar signals emitted according to the same modulation mode and reflected on the same target object, whose transit times differ depending on the direction of the target object. Therefore, the sub-signals of the detection information are always specific to radar signals of the same modulation mode, and the sub-signals of different detection information are specific to radar signals of different modulation modes. If different antennas are used, the transit times of the sub-signals of the detection information can differ depending on the direction. This allows angular information to be calculated by comparing the sub-signals with each other.

[0021] It is also conceivable that the at least two radar signals are emitted or received by different antennas of the radar sensor of the radar system, such that different transit times depend on the direction of the target object, and that a first sub-signal of the at least two sub-signals is specific to a first antenna of the different antennas, and a second sub-signal of the at least two sub-signals is specific to a second antenna of the different antennas. Sub-signals for multiple antennas m = 0, 1, 2... can be described, for example, as... In the form of. This represents the phase difference between the sub-signals of the first antenna 0 and the other antenna m, which depends on the transit time of the relevant radar signal received at antenna m. Additionally, a m The amplitude of the sub-signal is indicated, which in particular depends on the strength of the associated radar signal received at the antenna m. This indicates the initial stage. Now, if multiple modulation modes are used in addition to various antennas, then l can represent the corresponding index for the modulation mode. The aforementioned sub-signal also exists for other modulation modes and can be represented accordingly in the following form:

[0022] Advantageously, this invention can specify that the radar sensor of the radar system has at least two spaced-apart transmitting antennas and at least one receiving antenna, such that radar signals of the same modulation mode are emitted by the at least two transmitting antennas, and / or the radar sensor has at least two spaced-apart receiving antennas and at least one transmitting antenna, such that radar signals of the same modulation mode are received by the at least two receiving antennas. In this way, different transit times of the radar signals can be obtained for determining angular information based on the direction of the target object. This process can be repeated for other modulation modes.

[0023] It is also conceivable that the radar sensors of a radar system would perform the following steps:

[0024] - At least one first radar signal is emitted through at least one transmitting antenna of the radar sensor according to the first modulation mode.

[0025] - At least one second radar signal is transmitted through the at least one transmitting antenna according to the second modulation mode.

[0026] - For the first modulation mode, the first radar signal reflected from the target object and delayed by the transit time is received by at least one receiving antenna of the radar sensor.

[0027] - For the second modulation mode, the second radar signal reflected from the target object and delayed by the transit time is received by the at least one receiving antenna of the radar sensor.

[0028] Here, at least two transmitting antennas and / or at least two receiving antennas can be set to generate a transit time difference that depends on the direction.

[0029] In another possibility, it can be specified that the first detection information is specifically used for the at least one received first radar signal, and the second detection information is specifically used for at least one received second radar signal. Therefore, a sub-signal of the first detection information can also be assigned to the first radar signal and thus to the first modulation mode, and a sub-signal of the second detection information can also be assigned to the second radar signal and thus to the second modulation mode.

[0030] It is also advantageous that, within the scope of this invention, the following steps are performed prior to assembly:

[0031] - Identify the target object in the detection information so as to select, in particular, those sub-signals that have information about the same target object from the detection information of different modulation modes.

[0032] In this sense, it can also be described as matching different detection information. This can be used to make different modulation modes compatible with each other. Detection information for different modulation modes is based on measurements that may be performed sequentially in time. Therefore, the same target object can have different positions in the detection information. In other words, by identifying the target object in the detection information, a reflector representing a specific target object can be found. This can be achieved, for example, through peak identification. In this way, the peak values ​​in the spectrum of each modulation mode belonging to the same reflection center can be obtained. The same target object can also be identified in different detection information if it has the same relative velocity and / or the same distance and / or the same orientation as the radar sensor. Therefore, in order to identify the target object, the angular information about the orientation can also be initially determined in a conventional manner based on the (non-combined) detection information. The initially determined angular information is then used to identify the target object in the detection information. Furthermore, in this decision-making scheme, the assumption that the orientation of the target object does not change between measurements of the detection information can be used.

[0033] Similarly, in the method according to the invention, it can be specified that the information about the same target object includes at least one of the following, particularly provided by at least one frequency analysis performed from the detection information:

[0034] -The speed of the target object,

[0035] - Distance to the target object.

[0036] The detection information here corresponds, for example, to a possible multidimensional spectrum generated by frequency analysis, particularly Fourier transform.

[0037] Furthermore, within the scope of this invention, it is conceivable that the selected sub-signals have different phase information regarding the transit time of the radar signal (and particularly phase information that cannot be directly compared with each other), and / or that the following steps are performed before combination:

[0038] - Perform standardization of the selected sub-signals, especially the phase information of these sub-signals, so as to preferably make the sub-signals (and preferably their phase information) of different modulation modes comparable.

[0039] Due to different modulation modes, radar signals from different modulation modes can decouple over time, resulting in asynchronous initial chirps. Therefore, different phases of the radar signals can occur (even when the target orientation remains unchanged), making the phase information of different detection data incomparable. To still allow for combination, normalization can be performed on each detection data. Here, it's possible that during normalization, only the sub-signal of a unique detection data is always considered, i.e., sub-signals of different detection data (and therefore different modulation modes) are not compared to each other.

[0040] Another feasible approach is to perform the following steps for each detection record to perform standardization:

[0041] - Provides the first sub-signal for the first antenna of the radar sensor.

[0042] - Provide at least one second sub-signal for at least one second antenna of the radar sensor:

[0043] - Processed with the first sub-signal, in particular, except for the at least one second sub-signal.

[0044] Therefore, each detection information can have multiple sub-signals, which can be assigned to different antennas (receiving and / or transmitting antennas) of the radar sensor, i.e., generated by radar signals received or transmitted there. Thus, the phase information of this (selected) sub-signal of the detection information varies depending on the orientation of the target object.

[0045] For standardization, each detection information can be divided into complex signals, possibly always using the complex signals from the first antenna. For example, for each modulation mode (e.g., l = 0, 1, 2...), the standardized sub-signals... It can be obtained from the following formula:

[0046]

[0047] For example, therefore for l=0, the first sub-signal s00 of the first antenna is first divided by the (same) first sub-signal s00 of the first antenna to obtain the normalized first sub-signal of the first antenna. Then, the second sub-signal s01 of the second antenna is divided by the first sub-signal s00 of the first antenna to obtain the normalized second sub-signal of the second antenna. And so on. This can be repeated first for a single detection signal of a modulation mode and then for each detection signal of another modulation mode. In other words, antenna phase. Normalized to antenna phase Then, the normalized sub-signal is obtained in the form of Ideally, due to the standardization of different modulation modes l, the phase difference They are the same and therefore comparable. If the phase difference... Since interference causes differences, combining these sub-signals can lead to an improved signal-to-noise ratio.

[0048] Therefore, it can be stipulated that combination is performed by merging, in particular accumulating, sub-signals of the same antenna and different detection information, and therefore different modulation modes, and in particular normalized sub-signals. In other words, for each antenna m, all signals... They can be combined according to the following formula:

[0049]

[0050] Then, based on the signal obtained therefrom (i.e., the combined sub-signals s) m The determination of angle information is performed in the form of angle estimation (e.g., through digital beamforming).

[0051] Furthermore, within the scope of this invention, it can be specified that the determination of angle information based on combined detection information is performed by processing the sub-signals merged between different antennas, particularly through additional frequency analysis, as additional information after combination. Here, compared to angle estimation based solely on detection information of a single modulation mode, the addition of signals leads to an improvement in SNR and thus an improved angle estimation.

[0052] Furthermore, within the scope of this invention, it is conceivable that the radar system emits at least three different radar signals according to multi-mode operation, so as to obtain first, second and third detection information based on the received radar signals with three different modulation modes, wherein the radar signals of the radar system are modulated differently in different modulation modes.

[0053] The subject of this invention is also a radar system for vehicles. In addition to detecting target objects, this radar system can also be used to determine angular information about the direction of the corresponding target object. For this purpose, the radar system can have an (electronic) processing device for implementing the method according to the invention. Therefore, the radar system according to the invention provides the same advantages as those described in detail with reference to the method according to the invention. The processing device is designed, for example, as a microcontroller or digital signal processor, etc.

[0054] In another possibility, the radar system can be configured as a continuous wave radar. Specifically, the radar system can be designed as a frequency modulated continuous wave radar (FMCW radar). Attached Figure Description

[0055] Further advantages, features, and details of the invention will become apparent from the following description, in which embodiments of the invention are described in detail with reference to the accompanying drawings. Features mentioned herein in the claims and specification may be important to the invention individually or in any combination. In the drawings:

[0056] Figure 1 A schematic diagram of a vehicle equipped with a radar system according to the present invention is shown in the side view.

[0057] Figure 2 A schematic top view of a vehicle equipped with a radar system according to the present invention is shown.

[0058] Figure 3-6Further schematic diagrams of various parts of the radar system according to the present invention are shown.

[0059] Figure 7 A schematic diagram of the method steps according to the present invention is shown.

[0060] Figure 8 A schematic diagram of radar signals with different modulation modes is shown. Detailed Implementation

[0061] In the following figures, the same reference numerals are also used for the same technical features in different embodiments.

[0062] Figure 1 A vehicle 1 with a radar system 2 according to the invention is schematically shown in a side view. The vehicle 1 can use the radar system 2 according to the invention, for example, in conjunction with a driver assistance system. In this case, the radar system 2 can be used not only to determine distance and speed but also to determine angular information 200 about the direction of a target object 5. To perform the signal processing required for this purpose, the radar system 2 may have an electronic processing device 3 for implementing the method according to the invention. The processing device 3 is electrically connected to a radar sensor 4 having multiple antennas 20, 21.

[0063] exist Figures 3 to 6 The arrangement of antennas 20 and 21 is shown in more detail below. According to... Figure 3 The radar sensor 4 of radar system 2, for example, has at least two spaced-apart receiving antennas 20 and only one transmitting antenna 21. While... Figure 4 The radar sensor 4 is provided with at least two spaced-apart transmitting antennas 21 and only one receiving antenna 20. Figure 5 In this configuration, radar system 2 employs a MIMO (Multiple-Input Multiple-Output) transmit and receive scheme. Using more than two antennas 20, 21 allows the angle 240 (ejection angle and / or incident angle) of the radar signal to be determined by comparing different transit times based on the phase of the radar signal 230. Therefore, this allows angle information 200 to be determined as information about the direction of the target object 5 with respect to that angle 240.

[0064] The probability of determining angle information 200 is in Figure 6 This is shown in more detail below. It can be seen here that, with respect to the first receiving antenna 20', the transit time and therefore the phase of the radar signal 230 change due to the distance d between the receiving antennas 20 and due to the angle of incidence of the radar signal 230 and therefore the direction of the target object 5. For clarity, the first radar signal 231 and the second radar signal 232 are shown exemplarily.

[0065] The method according to the present invention for determining angular information 200 about the direction of a target object 5 in a radar system 2 for a vehicle 1 Figure 7 The diagram is schematically visualized. According to the first method step 101, first detection information 201 of the first modulation mode 251 of the radar system 2 can be provided here. According to the second method step 102, at least one second detection information 202 of at least one second modulation mode 252 of the radar system 2 can also be provided. Here, the detection information represents the “measured value” of the radar system 2, which is obtained by transmitting and receiving radar signals and, if necessary, by subsequent signal processing. Here, the first detection information 201 is generated by transmitting and receiving such a radar signal modulated according to the first modulation mode 251. The second detection information 202 is generated by transmitting and receiving such a radar signal 230 modulated according to the second modulation mode 252. If necessary, third detection information 203 of a third modulation mode 253 can also be provided. According to the third method step 103, the detection information 201, 202, and 203 of different modulation modes 251, 252, and 253 are combined. In this way, the determination of angle information 200 can be performed based on the combined detection information 201, 202, and 203.

[0066] The difference between radar signals 230 with different modulation modes lies particularly in the way radar signals 230 are modulated. Figure 8 It is shown that, for example, bandwidths B0, B1, and B2 can be different. Radar signal 230 can also be modulated differently in terms of frequency f. Different radar signals 251, 252, and 253 can be output sequentially in time and can also have different durations in terms of time t. Figure 2 This demonstrates that in this way, different detection areas can be covered by different modulation modes 251, 252.

[0067] Furthermore, the first and at least one second detection information 201, 202 may each have at least two sub-signals 210, each of which is specific to at least two radar signals 230 emitted according to the same modulation patterns 251, 252 and reflected from the same target object 5, and the transit times of the at least two radar signals differ depending on the direction of the target object 5. In other words, a first sub-signal 211 and at least one second sub-signal 212 may be provided for each detection information 201, 202. Since they are generated by the same detection information 201, 202, they are also specific to the same (unique) modulation patterns 251, 252. However, the sub-signals 251, 252 may be specific to different antennas 20, 21 of the radar system 2.

[0068] Figure 6An exemplary radar sensor with three receiving antennas 20 is shown. It can be seen that a distance d is provided between the receiving antennas 20, which affects the angle of incidence of the radar signal 230. Based on the received radar signal 230, the received signal can be electrically evaluated at each receiving antenna 20. For the received signal s... m The applicable term at the m-th receiving antenna is:

[0069]

[0070] Among them, a m Indicates the received amplitude. This represents the phase difference between the first receiving antenna 20' and the m-th receiving antenna 20. Indicates the initial phase.

[0071] Therefore, the applicable angle α is

[0072]

[0073] If the received signal is currently interfered with, then for the estimated angle The following relationship is derived:

[0074] in,

[0075] in n represents the measured phase difference. 0m This indicates the relevant noise term.

[0076] It is immediately apparent from these equations that expanding SNR (to a smaller n) 0m ) and enlarged aperture (larger d) 0m This leads to improved angle estimation (with a smaller n at the output of the estimator).

[0077] like Figure 8 As shown, radar system 2 can emit different modulation schemes for each cycle in multi-mode operation to accommodate different measurement capability requirements in the near-field and far-field ranges. This emission can be performed using the same or different transmitting antennas 21. For example, an unfocused omnidirectional transmitting antenna can be used for near-field applications, while a strongly focused antenna can be used for far-field applications. Here, different combinations of modulation modes 251, 252 and transmitting antennas 21 can have overlapping regions, where redundant information about the target object 5 exists (see...). Figure 2 ).

[0078] Basic signal processing (i.e., data detection and frequency analysis, and original target determination) can be performed separately for each modulation mode. Traditionally, information is fused at a higher level of abstraction (e.g., the original target level or object level). The original target here represents reflections (local peaks within the frequency range) and related attributes such as distance, velocity, angle, SNR, and different qualities. According to the present invention, multi-mode operation can be used to improve angle calculation. Generally, L modulation modes can be fused at the original signal level under the premise that the target object 5 is within the FoV (Field of View) of all modulation modes (see [reference]). Figure 2 Furthermore, all modulation modes can be based on... Figure 8 In time-division multiplexing, transmission occurs within a measurement period of duration T.

[0079] The above explanations of the various embodiments describe the invention only within the scope of examples. It goes without saying that the various features of the embodiments can be freely combined with each other, as long as this is technically meaningful and does not depart from the scope of the invention.

[0080] List of reference numerals

[0081] 1 vehicle

[0082] 2. Radar System

[0083] 3. Processing device

[0084] 4. Radar Sensors

[0085] 5. Target Object

[0086] 20 Receiving Antenna

[0087] 21 Transmitting Antenna

[0088] 20' First receiving antenna

[0089] 200° angle information

[0090] 201 First Detection Information

[0091] 202 Second Inspection Information

[0092] 203 Third Inspection Information

[0093] 210 sub-signals

[0094] 211 First Sub-signal

[0095] 212 Other signals

[0096] 230 Radar Signal

[0097] 231 First Radar Signal

[0098] 232 Second Radar Signal

[0099] 240 degrees

[0100] 251 First Modulation Mode

[0101] 252 Second Modulation Mode

[0102] 253 Third Modulation Mode

[0103] 20 and 21 antennas

[0104] f frequency

[0105] t time

[0106] 201, 202 Inspection Information

[0107] 251 and 252 modulation modes

[0108] Bx bandwidth

[0109] TX duration

Claims

1. A method for determining angular information (200) about the direction of a target object (5) in a radar system (2) for a vehicle (1), wherein, Perform the following steps: - Provides first detection information (201) of the first modulation mode (251) of the radar system (2). - Provide at least one second detection information (202) of at least one second modulation mode (252) of the radar system (2). - Combine the first detection information (201) and the second detection information (202) of different modulation modes (251, 252) to determine the angle information (200) based on the combined detection information (201, 202). Perform the following steps before combining: - Identify the target object (5) in the detection information so as to select sub-signals (210) with information about the same target object (5) from the detection information of different modulation modes respectively, and perform the combination in the following manner: merge the sub-signals (210) of the same antenna and different detection information of the radar sensor of the radar system and thus different modulation modes, and perform the determination of the angle information (200) based on the combined detection information in the following manner: after the combination, determine the direction of the target object (5) as additional information by processing the sub-signals (210) of different antennas that are merged with each other.

2. The method according to claim 1, characterized in that, The first detection information (201) and the at least one second detection information (202) each have at least two sub-signals (210), the corresponding at least two sub-signals (210) being specific for at least two radar signals (230), the at least two radar signals being emitted according to the same modulation mode and reflected on the same target object (5), and the transit time of the at least two radar signals being different according to the direction of the target object (5).

3. The method according to claim 2, characterized in that, The at least two radar signals (230) are emitted or received by different antennas of the radar sensor (4) of the radar system (2), such that different transit times depend on the direction of the target object (5), and such that the first sub-signal (211) of the at least two sub-signals (210) is specific to the first antenna of the different antennas and the second sub-signal (212) of the at least two sub-signals (210) is specific to the second antenna of the different antennas.

4. The method according to claim 2 or 3, characterized in that, The radar sensor (4) of the radar system (2) has at least two transmitting antennas (21) and at least one receiving antenna (20) arranged at a distance, such that radar signals (230) of the same modulation mode are emitted by the at least two transmitting antennas (21), and / or the radar sensor (4) has at least two receiving antennas (20) and at least one transmitting antenna (21) arranged at a distance, such that radar signals (230) of the same modulation mode are received by the at least two receiving antennas (20) to obtain different transit times of the radar signals (230) for determining angular information (200) depending on the direction of the target object (5).

5. The method according to claim 4, characterized in that, The following steps are performed by the radar sensor (4) of the radar system (2): - At least one first radar signal (231) is emitted through at least one transmitting antenna (21) of the radar sensor (4) according to the first modulation mode (251). - At least one second radar signal (232) is emitted through the at least one transmitting antenna (21) according to the second modulation mode (252). - For the first modulation mode (251), the first radar signal (231) reflected on the target object (5) and delayed by transit time is received by the at least one receiving antenna (20) of the radar sensor (4). - For the second modulation mode (252), the second radar signal (232) reflected on the target object (5) and delayed by transit time is received by the at least one receiving antenna (20) of the radar sensor (4).

6. The method according to claim 5, characterized in that, The first detection information (201) is specifically for the received at least one first radar signal (231) and the second detection information (202) is specifically for the received at least one second radar signal (232).

7. The method according to claim 1, characterized in that, The information regarding the same target object (5) includes at least one of the following information provided by at least one frequency analysis performed by the detection information (201, 202): -The speed of the target object (5), - Distance to the target object (5).

8. The method according to claim 1, characterized in that The selected sub-signal (210) has different phase information regarding the transit time of the radar signal (230), and the following steps are performed before combination: - Perform standardization of the selected sub-signal (210) so that sub-signals (210) of different modulation modes are comparable.

9. The method according to claim 8, characterized in that, To perform standardization, the following steps are performed for each piece of test information: - Provide the first sub-signal (211) for the first antenna of the radar sensor (4). - Provide at least one second sub-signal (212) for at least one second antenna for radar sensors. - The at least one second sub-signal (212) is processed with the first sub-signal (211).

10. The method according to claim 8, characterized in that, The sub-signal is phase information.

11. The method according to claim 9, characterized in that, The method includes dividing the at least one second sub-signal (212) by the first sub-signal (211).

12. The method according to claim 1, characterized in that, The sum of the same antenna and different detection information and therefore different modulation mode selections of the sub-signals (210).

13. The method according to claim 1, characterized in that, The sum of the same antenna and different detection information and therefore different modulation modes are selected and the sub-signals are standardized (210).

14. The method according to claim 1, characterized in that, After combination, as additional information, the direction of the target object (5) is determined by further frequency analysis through processing the sub-signals (210) of different antennas that are combined with each other.

15. The method according to claim 1, characterized in that, The radar system (2) emits at least three different radar signals (230) according to multi-mode operation in order to obtain first and third detection information based on the radar signals (230) received for three different modulation modes, wherein the radar signals (230) in different modulation modes are different in terms of the modulation of the frequency ramp emitted by each radar signal.

16. A radar system (2) for a vehicle (1) for determining angular information (200) about the direction of a target object (5), the radar system having a processing device (3) for implementing the method according to any one of claims 1 to 15.

17. The radar system according to claim 16, characterized in that, The radar system (2) is constructed as a continuous wave radar.

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