EP4662507A1 - Procédé de détection d'objet et système de capteur radar fmcw à résolution angulaire - Google Patents

Procédé de détection d'objet et système de capteur radar fmcw à résolution angulaire

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Publication number
EP4662507A1
EP4662507A1 EP23833830.5A EP23833830A EP4662507A1 EP 4662507 A1 EP4662507 A1 EP 4662507A1 EP 23833830 A EP23833830 A EP 23833830A EP 4662507 A1 EP4662507 A1 EP 4662507A1
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EP
European Patent Office
Prior art keywords
spectrum
radar sensor
angle
dimension
processor unit
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
EP23833830.5A
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German (de)
English (en)
Inventor
Benedikt Loesch
Steffen Bucher
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Robert Bosch GmbH
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Robert Bosch GmbH
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Publication date
Application filed by Robert Bosch GmbH filed Critical Robert Bosch GmbH
Publication of EP4662507A1 publication Critical patent/EP4662507A1/fr
Pending legal-status Critical Current

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Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S13/00—Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified
    • G01S13/02—Systems using reflection of radio waves, e.g. primary radar systems; Analogous systems
    • G01S13/06—Systems determining position data of a target
    • G01S13/42—Simultaneous measurement of distance and other co-ordinates
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S13/00—Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified
    • G01S13/02—Systems using reflection of radio waves, e.g. primary radar systems; Analogous systems
    • G01S13/06—Systems determining position data of a target
    • G01S13/08—Systems for measuring distance only
    • G01S13/32—Systems for measuring distance only using transmission of continuous waves, whether amplitude-, frequency-, or phase-modulated, or unmodulated
    • G01S13/34—Systems for measuring distance only using transmission of continuous waves, whether amplitude-, frequency-, or phase-modulated, or unmodulated using transmission of continuous, frequency-modulated waves while heterodyning the received signal, or a signal derived therefrom, with a locally-generated signal related to the contemporaneously transmitted signal
    • G01S13/343—Systems for measuring distance only using transmission of continuous waves, whether amplitude-, frequency-, or phase-modulated, or unmodulated using transmission of continuous, frequency-modulated waves while heterodyning the received signal, or a signal derived therefrom, with a locally-generated signal related to the contemporaneously transmitted signal using sawtooth modulation
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S13/00—Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified
    • G01S13/02—Systems using reflection of radio waves, e.g. primary radar systems; Analogous systems
    • G01S13/06—Systems determining position data of a target
    • G01S13/08—Systems for measuring distance only
    • G01S13/32—Systems for measuring distance only using transmission of continuous waves, whether amplitude-, frequency-, or phase-modulated, or unmodulated
    • G01S13/36—Systems for measuring distance only using transmission of continuous waves, whether amplitude-, frequency-, or phase-modulated, or unmodulated with phase comparison between the received signal and the contemporaneously transmitted signal
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S13/00—Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified
    • G01S13/02—Systems using reflection of radio waves, e.g. primary radar systems; Analogous systems
    • G01S13/50—Systems of measurement based on relative movement of target
    • G01S13/58—Velocity or trajectory determination systems; Sense-of-movement determination systems
    • G01S13/583—Velocity or trajectory determination systems; Sense-of-movement determination systems using transmission of continuous unmodulated waves, amplitude-, frequency-, or phase-modulated waves and based upon the Doppler effect resulting from movement of targets
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S13/00—Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified
    • G01S13/88—Radar or analogous systems specially adapted for specific applications
    • G01S13/93—Radar or analogous systems specially adapted for specific applications for anti-collision purposes
    • G01S13/931—Radar or analogous systems specially adapted for specific applications for anti-collision purposes of land vehicles
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
    • G01S7/02—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S13/00
    • G01S7/28—Details of pulse systems
    • G01S7/2813—Means providing a modification of the radiation pattern for cancelling noise, clutter or interfering signals, e.g. side lobe suppression, side lobe blanking, null-steering arrays
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
    • G01S7/02—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S13/00
    • G01S7/35—Details of non-pulse systems
    • G01S7/352—Receivers
    • G01S7/354—Extracting wanted echo-signals
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
    • G01S7/02—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S13/00
    • G01S7/35—Details of non-pulse systems
    • G01S7/352—Receivers
    • G01S7/356—Receivers involving particularities of FFT processing
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
    • G01S7/02—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S13/00
    • G01S7/40—Means for monitoring or calibrating
    • G01S7/4052—Means for monitoring or calibrating by simulation of echoes
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
    • G01S7/02—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S13/00
    • G01S7/41—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S13/00 using analysis of echo signal for target characterisation; Target signature; Target cross-section
    • G01S7/417—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S13/00 using analysis of echo signal for target characterisation; Target signature; Target cross-section involving the use of neural networks
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
    • B60W2420/00—Indexing codes relating to the type of sensors based on the principle of their operation
    • B60W2420/40—Photo, light or radio wave sensitive means, e.g. infrared sensors
    • B60W2420/408—Radar; Laser, e.g. lidar

Definitions

  • the invention relates to a method for object detection with an angle-resolving FMCW radar sensor, in which an at least three-dimensional spectrum with a distance dimension, a Doppler dimension indicating the relative speeds of the objects and an angle dimension is generated on the basis of received signals from several receiving channels of the radar sensor, wherein the radar sensor is undersampling in the Doppler dimension and consequently the spectrum in this dimension is incomplete and ambiguous and wherein a frequency modulation scheme with several nested sequences of temporally equidistant frequency ramps is used to resolve the ambiguities and for each of several speed hypotheses, a speed-dependent phase offset between the frequency ramps belonging to the different sequences is determined on the basis of known time offsets between the frequency ramps belonging to the different sequences. received signals and compared with the measured phase offset.
  • the invention relates to a method and a radar sensor system for motor vehicles.
  • Radar sensors are often used to monitor the environment in driver assistance systems because they allow direct measurement of the distance (d), the relative speed (v), as well as the azimuth and elevation angle (a, 0) of the objects.
  • Radar sensors are known that work with a sequence of identical, relatively short frequency ramps, so-called “rapid chirps", which have a high frequency swing in relation to their duration and are therefore so steep that the distance-dependent component of the frequency shift dominates in the baseband signal, while the Doppler shift is sampled by the sequence of ramps.
  • a sufficiently high repetition rate of the short ramps is therefore required.
  • the time offset between successive short ramps must be less than half the period of the Doppler frequency.
  • Such a short time offset places high demands on the analog hardware.
  • a corresponding number of such short ramps would be necessary. This leads to a comparatively high memory requirement and computing effort when evaluating the data.
  • Ramps result in undersampling of the Doppler shift, so that the information obtained about the relative velocity is ambiguous.
  • DE 10 2014 212 280 A1 discloses a method with temporally nested ramp sequences that allows a clear velocity estimation by evaluating the relative phases between the same peak positions in the two-dimensional spectra after a two-dimensional fast Fourier transform (2D-FFT) of each ramp sequence and comparing them with a model relationship for the ambiguity hypotheses.
  • the resolution of the ambiguities is referred to below as "Velocity Ambiguity Resolution (VAR)”.
  • VAR Vector Ambiguity Resolution
  • the method was extended to several transmitting antennas that are operated in time multiplex or code multiplex with periodic codes via the chirps.
  • a target can also be masked by a second target that is located in a neighboring distance Doppler cell, so that detection is prevented.
  • DE 10 2021 213 495 describes a method that can, on the one hand, increase the range or sensitivity of the radar sensor so that weaker targets can be detected earlier, and, on the other hand, avoid the negative effects of spectral superposition of targets.
  • the modulation sequences are coherently summed before detection using a "speed beamformer".
  • the reception power can be increased for "desired” speeds and reduced for "unwanted” speeds.
  • DE 10 2020 202 498 A1, DE 10 2020 202 499 A1 and DE 10 2020 202 500 A1 describe methods for MIMO radar systems (multiple input multiple output) in which high-resolution spectra are evaluated in a first detection stage, but which are ambiguous in both the Doppler dimension and the angular dimension.
  • the spectra obtained for different ramp sequences and different combinations of transmit and receive antennas are added non-coherently, and the object is detected using the sum spectrum thus formed. Ambiguity hypotheses are then tested for the objects found in order to resolve the ambiguities.
  • the phase corrected complex amplitudes of the detection are added coherently so that a lower resolution but unambiguous spectrum is obtained in a second detection stage.
  • the object of the invention is to further increase the sensitivity of detection and to improve the robustness against multi-target scenarios.
  • This object is achieved according to the invention in that, during phase alignment, angle-dependent phase offsets of the various receiving channels are evaluated together with the speed-dependent phase offsets and a complete and unambiguous spectrum is reconstructed and that the object detection takes place on the basis of the reconstructed spectrum.
  • the information contained in the large number of multidimensional spectra is used extensively to reconstruct an "ideal" spectrum that would be obtained in the given situation if the radar sensor were not undersampling in the Doppler dimension or in the angle dimension. Since the actual object detection only takes place on the basis of this reconstructed spectrum, which is both high-resolution and unambiguous, an improved object separation capability is achieved. In addition, the joint processing of speed information and angle information significantly reduces the probability of peak overlaps and masking of objects. By evaluating the information from a large number of individual spectra, an increased sensitivity is also achieved.
  • VAR Vehicle Ambiguity Resolution
  • ANG Angle Estimation
  • Such joint processing can be realized by coherent velocity and angle beamforming.
  • Angle beamforming as such is a well-known method in which the phases of the signals received in the various (real or virtual) receiving channels are corrected in such a way that the phase shifts dependent on the detection angle and caused by the spatial offsets between the various transmit and receive antennas are compensated in such a way that the sensor is predominantly sensitive to "beams" coming from a certain direction.
  • velocity beamforming the phase shifts dependent on the relative velocity are compensated from ramp to ramp within a ramp sequence in an analogous manner, so that the sensitivity for objects with a certain relative velocity is increased.
  • coherent velocity and angle beamforming both phase corrections are combined. In this way, the sensitivity for certain critical points in the multidimensional spectrum can be specifically increased so that overlaps of closely spaced peaks can be better resolved. Conversely, signals from interfering objects such as guide posts on the side of the road can also be specifically suppressed.
  • Joint processing suppresses side lobes more than would be the case with separate or sequential processing, increasing the dynamic range for targets with different speeds and angles and allowing weaker targets to be detected
  • iterative approaches are also conceivable for joint processing, in which the estimated values for the two dimensions (speed and angle) are alternately optimized.
  • a neural network is trained to reconstruct the corresponding unambiguous spectrum from the ambiguous spectra obtained by subsampling.
  • the necessary training data for the neural network can be created, for example, by capturing one and the same environment with a radar sensor that works with subsampling and a radar sensor that works without subsampling but otherwise has equivalent specifications.
  • the training data can also be generated simulatively using suitable simulation methods (ray tracing, channel simulation, etc.).
  • the method described here can be used to resolve ambiguities in the Doppler dimension as well as ambiguities in the azimuth angle and/or elevation angle.
  • the method is also advantageous for radar sensors that have a fully occupied antenna array and therefore provide a clear spectrum in the angular dimension.
  • the invention also relates to a radar sensor system in which the method according to the invention is implemented.
  • a radar sensor for motor vehicles has an integrated processor unit that evaluates the digital received signals and calculates the distances, relative speeds and location angles of the located objects.
  • a classic evaluation as described in the literature references cited above, can also be carried out in parallel with an improved evaluation according to the invention and used as a second, algorithmically independent path in the environment detection.
  • the classic evaluation and the improved evaluation can then optionally be implemented on different control units.
  • the classic evaluation can be implemented on the radar sensor, while the improved evaluation is implemented on an external processor unit.
  • a further possibility is to carry out the detailed processing according to the invention only for those regions of the two-dimensional distance and speed spectrum that are of particular interest in a given situation.
  • Fig. 1 is a block diagram of an FMCW radar sensor
  • Fig. 2 is a modulation pattern with two sequences of similar ramps transmitted with a time offset T12;
  • Fig. 3 Antenna arrays for an angle-resolving radar sensor
  • Fig. 4 is a block diagram of an internal processor unit of a radar sensor and an external processor unit, which together form a radar sensor system according to the invention
  • Fig. 5 is a schematic representation of input data sets for a processing procedure in the method according to the invention.
  • Fig. 6 is a flow chart of the process.
  • Fig. 1 shows a simplified block diagram of an FMCW radar sensor 10 which is installed in a motor vehicle, for example, and is used to measure distances d, relative speeds v, and location angles of objects 12, 14, for example of vehicles driving ahead.
  • the radar sensor 10 has a voltage-controlled oscillator 16 which supplies a frequency-modulated transmission signal via a mixer 18 to a transmitting and receiving device 20, from which the signal is transmitted in the direction of the objects 12, 14.
  • the signal reflected from the objects is received by the transmitting and receiving device 20 and mixed in the mixer 18 with a portion of the transmission signal.
  • a Baseband signal bi, b2 which is digitized and further evaluated in a processor unit 22.
  • the processor unit 22 contains a control part 24 which controls the function of the oscillator 16.
  • the frequency of the transmission signal supplied by the oscillator is modulated within a radar measurement with sequences of rising or falling ramps.
  • Fig. 2 shows the transmission frequency f of the transmission signal 28 plotted against time t.
  • two sequences of ramps with identical ramp parameters are transmitted using a transmission antenna, which are temporally interleaved.
  • a first sequence 30 of ramps 32 is shown in Fig. 2 with solid lines, while a second sequence 34 of ramps 36 is shown with dashed lines.
  • the number i of the sequence to which a ramp belongs and the respective ramp index j of the ramp within a sequence are indicated.
  • the ramps 36 of the second sequence 34 are each shifted by a time offset T12 relative to the ramps 32 of the first sequence 30 with the same ramp index j.
  • the successive ramps 32 and 36 are shifted from one another by a time interval Tr2r.
  • the time interval Tr2r is therefore the same for both sequences. Furthermore, there is a pause P between two successive ramps of a sequence.
  • components bi which originate from the ramps 32 of the first sequence 30, alternate with components b2 , which originate from the ramps 36 of the sequence 34. Due to the time offset T12 between the ramps 32 and 36, the components bi and b2 have a relative phase shift which, for each located object, depends on the relative speed of the object in question. This phase shift can be calculated and enables the resolution of ambiguities which arise due to undersampling in the Doppler dimension.
  • Fig. 1 In the simplified example of Fig. 1, only two nested ramp sequences 30 and 34 are provided. In practice, however, the number of nested frequency ramps can be significantly larger, so that the ambiguities can be resolved more precisely or a larger degree of undersampling can be tolerated.
  • Fig. 3 shows a schematic diagram of an antenna array of the transmitting and receiving device 20.
  • Several transmitting antennas 38 form a transmitting array 40 (TX), and several receiving antennas 42 form a receiving array 44 (RX).
  • TX transmitting array
  • RX receiving array 44
  • both arrays are two-dimensional, so that MIMO angle measurements are possible in both azimuth and elevation.
  • the receiving antennas 42 are arranged at equal intervals in an angular resolution direction y, e.g. in the direction of the azimuth.
  • the distances between the individual receiving antennas are so large that a large aperture and a correspondingly high angular resolution can be achieved with just a few antennas.
  • the distances from antenna to antenna are greater than half the wavelength of the radar radiation, so that the Nyquist uniqueness criterion is not met.
  • the receiving antennas 42 are also arranged at equal distances in elevation (in the angular resolution direction z), and in this direction too, the antenna spacing is so large that non-unique undersampling occurs. 19
  • the transmitting antennas 38 of the transmitting array 44 are arranged at irregular intervals in azimuth, but the intervals are chosen so that a clear angle measurement is possible. However, the aperture is significantly smaller than that of the receiving array 44, so that the angular resolution is lower.
  • the transmitting array 40 is also designed for clear angle measurements with a small aperture in elevation.
  • a synthetic array 46 is also shown, which is obtained when each of the receiving antennas 42 is combined with each of the transmitting antennas 38, so that the differences in the propagation times of the signals from the transmitting antennas to the object and from the object to the receiving antennas are added together.
  • this virtual array 46 determines the resolution of the radar sensor.
  • the two angular resolution directions y and z in the receiving array 38 are also decoupled from one another, since for each y position of the receiving antennas, all z positions are also occupied by receiving antennas.
  • the transmit array 40 is an example of a non-decoupled array in which not all z positions are occupied for some y positions (the two right-hand positions in Fig. 3).
  • a decoupled array makes data evaluation easier, while a non-decoupled array requires fewer antenna elements.
  • the decision between decoupled and non-decoupled arrays can be made differently for both the transmit side and the receive side, depending on the respective requirements.
  • the equidistant arrangement of the antenna elements also facilitates the evaluation of the data, as it enables the use of a fast Fourier transformation (FFT), for example.
  • FFT fast Fourier transformation
  • the non-equidistant arrangement of the antennas, as here with the transmitting antennas 38 has the advantage that the unambiguous angle range can be optimized for a given aperture.
  • Fig. 4 shows a block diagram of the processor unit 22 of the radar sensor shown in Fig. 1 and an external processor unit 48 which serves to further process the signals preprocessed in the processor unit 22 of the radar sensor.
  • a one-dimensional spectrum 52 is formed from the baseband signals bi and b2, ..., which are obtained from a single frequency ramp 32 or 36, by one-dimensional fast Fourier transformation (FFT).
  • FFT fast Fourier transformation
  • Each object located by the radar sensor is shown in this spectrum as a signal peak at a frequency that indicates the distance d of the object in question.
  • the digital data representing the spectra 52 thus obtained are transmitted to the external processor unit 48 and further processed there.
  • the spectra 52 that originate from the ramps of the same ramp sequence 30 or 34 are subjected to a further Fourier transformation.
  • each one-dimensional spectrum 52 is divided into a plurality of distance cells, and the Fourier transformation in the transformation stage 54 is carried out separately for each distance cell.
  • the signals obtained from the successive ramps of an individual sequence vary periodically with a frequency that depends on the relative speed v of the object being located.
  • the transformation stage 54 provides a two-dimensional spectrum 56 with a distance dimension d and a speed dimension or Doppler dimension v for each ramp sequence.
  • each of the transmitting antennas 38 can be combined with each of the receiving antennas 42.
  • Each receiving antenna 32 supplies an input signal for a receiving channel of the radar sensor. The evaluation of this signal depends on which of the transmitting antennas 38 was active on the relevant frequency ramp.
  • the signals For several receiving antennas 42 that have different distances from the active transmitting antenna 38 in the (horizontal) angular resolution direction y, the signals have a phase offset that depends on the distance between the receiving antennas 42 in the direction y and on the azimuth angle a of the located object. Accordingly, the signals from receiving antennas 42, which are at different distances from the active transmitting antenna 38 in the direction z, have a phase offset which depends on the distance between the receiving antennas in this direction and on the elevation angle 0 of the located object.
  • a different two-dimensional spectrum 56 is obtained for each of these combinations and for each of the ramp sequences 30 or 34.
  • N se q is the number of ramp sequences 30, 34
  • NTX is the number of transmit antennas
  • NRX is the number of receive antennas
  • the total number of spectra 56 that can be evaluated is therefore Nseq x NTX x NRX.
  • Each of these spectra 56 is ambiguous on its own due to the undersampling in the velocity dimension v. However, if the information from the spectra 56 obtained for the N se q different frequency ramps is used, it is possible to resolve this ambiguity.
  • the spectra obtained for the same ramp sequence but for different combinations of transmitting and receiving antennas are redundant, so that it would be sufficient to evaluate one of these sequences of spectra.
  • an angle estimate in azimuth and elevation can be made using the spectra obtained for different combinations of transmitting and receiving antennas.
  • the spectra 56 can be arranged in two sequences, namely one in which the spectra are arranged according to increasing distance between the transmitting and receiving antenna in the y direction, and one in which the spectra are arranged according to increasing distance in the z direction. The totality of the two sequences of two-dimensional spectra 56 then forms a four-dimensional spectrum.
  • an angle estimate in azimuth or elevation can then be made using known methods.
  • the spectra 56 are in principle redundant; they relate to the same combination of transmitting and receiving antennas but belong to different ramp sequences. If the antenna spacing forms a uniform grid, as is the case with the receiving antennas 42 in Fig. 3, for example, the angle estimate can be made efficiently using fast Fourier transformation, so that four-dimensional spectra with the dimensions distance d, speed v, azimuth angle a and elevation angle 0 are obtained. In the case of an understaffed antenna array, ambiguities can also arise that must be resolved using known methods.
  • VAR velocity ambiguity resolution
  • ANG angle estimation
  • phase shifts which are both speed- and angle-dependent
  • the information lost due to undersampling is at least partially recovered by phase matching between the spectra obtained for different frequency ramps and different antenna combinations.
  • a reconstruction stage 58 is therefore provided for the purpose of jointly evaluating the spectra 56 and combining the resolution of the velocity and, if applicable, angle ambiguities using a common single or multi-objective model for the velocity and angle-dependent phase shifts to reconstruct a unique four-dimensional spectrum 60, in which each signal peak uniquely indicates the distance d, the relative velocity v, the azimuth angle a and the elevation angle 0 of the object in question.
  • a phase correction is carried out on the spectral values in the unique spectrum 60 using a correction function a(v, a, 0) for different combinations of relative speed v, azimuth angle a and elevation angle 0, and the spectral values are added coherently over the dimensions v, a and 0.
  • the coherent summation suppresses secondary maxima in the spectrum and increases the signal-to-noise ratio so that object detection can be carried out with high sensitivity and selectivity in a detection stage 62.
  • the processor unit 48 thus provides unique values for the distance d, the relative speed v, the azimuth angle a and the elevation angle 0 for each object detected with high sensitivity.
  • a single two-dimensional (ambiguous) spectrum 56 is shown, which is divided into distance cells 66 in the distance dimension d and into Doppler cells 68 in the Doppler or velocity dimension v.
  • the input data for the reconstruction stage 58 forms a data structure 70 which shall be referred to as a "range gate”. This
  • Data structure includes the spectral values of all spectra 56 belonging to a single distance cell 66. This data structure thus includes the spectral values for all Doppler cells in the spectra 56 for all ramp sequences and all combinations of transmit and receive antennas.
  • the data structure 72 of the input data is a group of several adjacent range gates, so that variations in the spectral values in the distance dimension can also be taken into account when evaluating the data.
  • the input data forms a data structure 74 consisting of a single distance and Doppler cell in all spectra 56 for the various ramp sequences and antenna combinations.
  • the input data may be a "patch" 76 containing multiple adjacent distance and Doppler cells.
  • the input data is converted into the reconstructed range Doppler azimuth and elevation spectrum 60 for the respective range gate or the range and Doppler cells of the respective data structure 72, 74 or 76 using an algorithm based on the common single or multiple target model.

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  • Engineering & Computer Science (AREA)
  • Radar, Positioning & Navigation (AREA)
  • Remote Sensing (AREA)
  • Physics & Mathematics (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • General Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Artificial Intelligence (AREA)
  • Evolutionary Computation (AREA)
  • Radar Systems Or Details Thereof (AREA)

Abstract

L'invention concerne un procédé de détection d'objet au moyen d'un capteur radar FMCW à résolution angulaire. Un spectre au moins tridimensionnel (56) avec une dimension d'espacement (d), une dimension Doppler qui indique la vitesse relative (v) des objets, et une dimension angulaire (α, θ) est généré à l'aide des signaux reçus de plusieurs canaux de réception du capteur radar, le capteur radar effectuant un sous-échantillonnage dans la dimension Doppler, et le spectre (56) étant par conséquent incomplet et ambigu dans la dimension Doppler. Afin de résoudre les ambiguïtés, un schéma de modulation de fréquence avec une pluralité de séquences imbriquées de rampes de fréquence temporellement équidistantes est utilisé, et pour chaque hypothèse d'une pluralité d'hypothèses de vitesse, un décalage de phase basé sur la vitesse entre les signaux reçus obtenus pour les différentes séquences est modélisé en utilisant des décalages temporels connus entre les rampes de fréquence appartenant aux différentes séquences et est comparé avec le décalage de phase mesuré. L'invention est caractérisée en ce que, pendant la comparaison de phase, les décalages de phase basés sur l'angle des différents canaux de réception sont analysés conjointement avec les décalages de phase basés sur la vitesse, et un spectre complet et sans ambiguïté (60) est reconstruit. La détection d'objet (60) est réalisée sur la base du spectre reconstruit (60).
EP23833830.5A 2023-02-08 2023-12-20 Procédé de détection d'objet et système de capteur radar fmcw à résolution angulaire Pending EP4662507A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE102023200997.8A DE102023200997A1 (de) 2023-02-08 2023-02-08 Verfahren zur Objektdetektion und winkelauflösendes FMCW-Radarsensorsystem
PCT/EP2023/086920 WO2024165224A1 (fr) 2023-02-08 2023-12-20 Procédé de détection d'objet et système de capteur radar fmcw à résolution angulaire

Publications (1)

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EP4662507A1 true EP4662507A1 (fr) 2025-12-17

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EP (1) EP4662507A1 (fr)
JP (1) JP2026504523A (fr)
KR (1) KR20250143812A (fr)
CN (1) CN121127764A (fr)
DE (1) DE102023200997A1 (fr)
WO (1) WO2024165224A1 (fr)

Family Cites Families (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102014212280A1 (de) 2014-06-26 2015-12-31 Robert Bosch Gmbh Radarmessverfahren
DE102014212284A1 (de) 2014-06-26 2015-12-31 Robert Bosch Gmbh MIMO-Radarmessverfahren
DE102014223990A1 (de) 2014-11-25 2016-05-25 Robert Bosch Gmbh Verfahren zum Erfassen von mindestens zwei Zielen mit einem Radarsensor und Radarsensor
US10151826B2 (en) * 2016-02-16 2018-12-11 Infineon Technologies Ag Radar employing preacquisition ramps
DE102017200317A1 (de) 2017-01-11 2018-07-12 Robert Bosch Gmbh Radarsensor und Verfahren zur Bestimmung einer Relativgeschwindigkeit eines Radarziels
DE102020202500A1 (de) 2020-02-27 2021-09-02 Robert Bosch Gesellschaft mit beschränkter Haftung MIMO-Radarsystem
DE102020202499A1 (de) 2020-02-27 2021-09-02 Robert Bosch Gesellschaft mit beschränkter Haftung MIMO-Radarsystem
DE102020202498A1 (de) 2020-02-27 2021-09-02 Robert Bosch Gmbh MIMO-Radarsystem
US11762079B2 (en) * 2020-09-30 2023-09-19 Aurora Operations, Inc. Distributed radar antenna array aperture
US11927664B2 (en) * 2021-02-25 2024-03-12 Nxp B.V. Radar-based detection using angle of arrival estimation based on sparse array processing
DE102021213495A1 (de) 2021-11-30 2023-06-01 Robert Bosch Gesellschaft mit beschränkter Haftung Radarmessverfahren

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DE102023200997A1 (de) 2024-08-08
JP2026504523A (ja) 2026-02-05
CN121127764A (zh) 2025-12-12
WO2024165224A1 (fr) 2024-08-15
KR20250143812A (ko) 2025-10-02

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