Millimeter wave radar bumper false target suppression method, device and equipment and storage medium

Abstract

The invention discloses a millimeter wave radar bumper false target suppression method, device and equipment and a storage medium, and the method comprises the steps: obtaining a radar echo signal, and generating an RD image based on the radar echo signal; determining candidate false target areas in the RD image according to radar frequency hopping characteristics and bumper false target characteristics; constructing an energy storage array based on the candidate false target area, and initializing the energy storage array; updating the energy storage array in real time, and performing energy and angle consistency verification on points in the candidate false target area based on the energy storage array by using an inter-frame consistency verification mechanism to obtain a verification result; and marking points meeting energy consistency verification and angle consistency verification in the verification result as false target points, and performing suppression operation on the false target points. Compared with the prior art, the method has the advantages that the distinguishing accuracy of the false target and the real target of the bumper is improved, and the suppression difficulty of the false target of the bumper is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of radar signal processing, in particular to a millimeter wave radar bumper false target suppression method, device, equipment and storage medium. BACKGROUND

[0002] Millimeter wave radar has become one of the core sensors of advanced driver assistance systems (ADAS) and autonomous vehicles due to its all-weather and all-day working ability. In the typical installation mode, the radar is arranged behind the front bumper to realize the detection of the front obstacles by transmitting and receiving electromagnetic waves. However, after the electromagnetic waves penetrate the bumper and reflect multiple times on the surface of the metal structure such as the bumper beam and the cavity, a "bumper false target" point track with relatively fixed position and weak energy is formed. These point tracks show similar detection characteristics with real targets in the range-doppler (RD) graph, and are easily determined as effective targets by the constant false alarm rate (CFAR) detector, and then mixed into the subsequent tracking queue, causing false alarms or false braking and reducing the system reliability.

[0003] The existing suppression methods mainly develop from two paths of hardware and algorithm. In the hardware aspect, by locally pasting wave-absorbing materials on the inner side of the bumper, optimizing the curved surface shape or improving the radar radio frequency front end side lobe index, the false target energy can be reduced in the sample vehicle stage. However, after the vehicle enters mass production, the bumper thickness, paint layer dielectric constant, radar installation tolerance and environmental temperature and humidity changes will all cause the false target energy to drift, and the hardware solution cannot guarantee consistent results throughout the life cycle, and increases the cost of materials and processes. In the algorithm aspect, the early scheme uses the explicit characteristics of the false target "short distance, zero speed and weak energy" to set a threshold to filter the single frame RD graph. With the popularization of waveform frequency hopping technology, the Doppler index of the false target in the same distance unit will systematically shift with the frequency hopping parameters (frequency step Δf, pulse repetition period Tc, center frequency fc), causing the fixed threshold to fail. At the same time, the speed characteristics of real stationary targets (such as guardrails and road signs) overlap with those of false targets in low-speed scenarios, further reducing the accuracy of distinguishing between them. In addition, different radar individuals have energy differences due to production line tolerances, and fixed thresholds are prone to over-deletion or deletion, making it difficult to adapt to mass production requirements.

[0004] Therefore, there is an urgent need for a millimeter wave radar bumper false target suppression method that can improve the accuracy of distinguishing between bumper false targets and real targets, and thus reduce the difficulty of suppressing bumper false targets. SUMMARY

[0005] The main purpose of the present application is to provide a millimeter wave radar bumper false target suppression method, device, equipment and storage medium, which aims to solve the technical problem that the existing technology has low accuracy in distinguishing between bumper false targets and real targets, resulting in greater difficulty in suppressing bumper false targets.

[0006] To achieve the above object, the application provides a millimeter wave radar bumper false target suppression method, which comprises the following steps: acquiring a radar echo signal and generating an RD graph based on the radar echo signal; determining a candidate false target region in the RD graph according to radar frequency hopping characteristics and bumper false target characteristics; constructing an energy storage array based on the candidate false target region and initializing the energy storage array; updating the energy storage array in real time, performing energy and angle consistency verification on points in the candidate false target region based on the energy storage array by using an inter-frame consistency verification mechanism, and obtaining a verification result; marking points meeting energy consistency verification and angle consistency verification in the verification result as false target points and performing suppression operation on the false target points.

[0007] Optionally, the step of determining a candidate false target region in the RD graph according to radar frequency hopping characteristics and bumper false target characteristics comprises: determining a maximum distance threshold based on bumper multiple reflection paths; determining a Doppler offset according to a speed calculation formula of a millimeter wave radar frequency hopping signal and setting a Doppler threshold with the Doppler offset as the center; collecting units in the RD graph meeting the maximum distance threshold and the Doppler threshold as a candidate false target region.

[0008] Optionally, after the step of collecting units in the RD graph meeting the maximum distance threshold and the Doppler threshold as a candidate false target region, the method further comprises: acquiring a self-vehicle motion speed and a preset speed threshold, comparing the self-vehicle motion speed with the preset speed threshold, and obtaining a speed comparison result; when the speed comparison result indicates that the self-vehicle motion speed is greater than the preset speed threshold, performing the steps of constructing an energy storage array based on the candidate false target region and initializing the energy storage array.

[0009] Optionally, the step of constructing an energy storage array based on the candidate false target region and initializing the energy storage array comprises: determining an upper energy threshold and a lower energy threshold of a false target point according to line information and historical project experience values; constructing an energy storage array based on distance unit distribution of the candidate false target region; According to the energy upper limit threshold, an energy value corresponding to each distance unit in the energy storage array is initialized and assigned.

[0010] Optionally, the step of updating the energy storage array in real time comprises: Energy information of each unit point in the candidate false target region in the current frame is extracted, and the energy storage array is updated based on the energy information. The number of first units with energy greater than the energy lower limit threshold and the number of second units detected by the constant false alarm rate in the energy storage array are counted. When the number of first units and the number of second units are greater than the first proportion threshold and the second proportion threshold respectively, the inter-frame existence count is increased, and the angle information of the current frame is written into the energy storage array.

[0011] Optionally, the step of using an inter-frame consistency checking mechanism to check the points in the candidate false target region based on the energy storage array to obtain a checking result comprises: The target energy value and the target angle information of the point in the candidate false target region in the current frame detected by the constant false alarm rate are extracted. The target energy value is compared with the historical energy mean value in the energy storage array to obtain an energy difference result. The target angle information is compared with the angle information of the corresponding distance unit in the energy storage array to obtain an angle difference result. The energy difference result and the angle difference result are compared with an energy threshold and an angle threshold respectively, and the checking result is determined according to the comparison result.

[0012] Optionally, the step of marking the points in the checking result that meet the energy consistency check and the angle consistency check as false target points and performing suppression operation on the false target points comprises: The inter-frame existence count is obtained, and the ratio of the inter-frame existence count to the maximum frame count value is determined. When the ratio is greater than a preset proportion threshold, the points in the checking result that meet the energy consistency check and the angle consistency check are marked as false target points, and suppression operation is performed on the false target points.

[0013] In addition, in order to achieve the above purpose, the application further provides a millimeter wave radar bumper false target suppression device, which comprises: A signal processing model is used to obtain a radar echo signal, and generate an RD graph based on the radar echo signal. A region determination module is configured to determine a candidate false target region in the RD map according to radar frequency hopping characteristics and bumper false target characteristics; An array construction module is configured to construct an energy storage array based on the candidate false target region and initialize the energy storage array; An array updating module is configured to update the energy storage array in real time and perform energy and angle consistency verification on points in the candidate false target region based on the energy storage array by using an inter-frame consistency verification mechanism to obtain a verification result; A target suppression module is configured to mark points in the verification result that meet energy consistency verification and angle consistency verification as false target points and perform suppression operations on the false target points.

[0014] In addition, to achieve the above object, the application further provides a millimeter wave radar bumper false target suppression device, which comprises a memory, a processor and a millimeter wave radar bumper false target suppression program stored in the memory and executable on the processor, and the millimeter wave radar bumper false target suppression program is configured to implement the steps of the millimeter wave radar bumper false target suppression method as described above.

[0015] In addition, to achieve the above object, the application further provides a storage medium, which stores a millimeter wave radar bumper false target suppression program, and the millimeter wave radar bumper false target suppression program implements the steps of the millimeter wave radar bumper false target suppression method as described above when executed by a processor.

[0016] The application discloses acquiring a radar echo signal and generating an RD map based on the radar echo signal; determining a candidate false target region in the RD map according to radar frequency hopping characteristics and bumper false target characteristics; constructing an energy storage array based on the candidate false target region and initializing the energy storage array; updating the energy storage array in real time and performing energy and angle consistency verification on points in the candidate false target region based on the energy storage array by using an inter-frame consistency verification mechanism to obtain a verification result; marking points in the verification result that meet energy consistency verification and angle consistency verification as false target points and performing suppression operations on the false target points. Since the application determines a candidate false target region in the RD map according to radar frequency hopping characteristics and bumper false target characteristics, performs energy and angle consistency verification on points in the candidate false target region based on an energy storage array by using an inter-frame consistency verification mechanism, compared with the prior art, the application improves the accuracy of distinguishing bumper false targets from real targets and reduces the difficulty of suppressing bumper false targets. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 A flowchart of a first embodiment of the millimeter wave radar bumper false target suppression method of the application is shown in FIG. 1. Figure 2 A comparison diagram of the false target of the radar bumper and the static target on the road is shown in FIG. 2. Figure 3 A comparison diagram of the false target of the radar bumper and the static target on the road is shown in FIG. 2. Figure 4 A flowchart of a second embodiment of the millimeter wave radar bumper false target suppression method of the application is shown in FIG. 3. Figure 5 A flowchart of a third embodiment of the millimeter wave radar bumper false target suppression method of the application is shown in FIG. 4. Figure 6 A structural block diagram of a first embodiment of the millimeter wave radar bumper false target suppression device of the application is shown in FIG. 5. Figure 7 A structural diagram of the millimeter wave radar bumper false target suppression device related to the hardware running environment of the embodiment scheme of the application is shown in FIG. 6.

[0018] The implementation of the object of the application, the functional features and the advantages will be further described with reference to the embodiments and the accompanying drawings. DETAILED DESCRIPTION

[0019] It should be understood that the specific embodiments described herein are only used to explain the application and not to limit the application.

[0020] The embodiment of the application provides a millimeter wave radar bumper false target suppression method, which refers to Figure 1 , Figure 1 A flowchart of a first embodiment of the millimeter wave radar bumper false target suppression method of the application is shown in FIG. 1.

[0021] In the embodiment, the millimeter wave radar bumper false target suppression method comprises steps S10-S50: Step S10: Obtain a radar echo signal, and generate an RD diagram based on the radar echo signal.

[0022] It should be noted that the execution subject of the embodiment can be a signal processing unit integrated in a vehicle-mounted millimeter wave radar itself, which is applied to a bumper false target suppression scene and has functions of data processing, network communication and program running.

[0023] It should be understood that the radar echo signal refers to a high-frequency analog signal captured by a receiving antenna after a linear frequency modulation continuous wave (FMCW) or frequency hopping pulse transmitted by a millimeter wave radar is reflected by a target. The signal has carried target distance and speed information and is expressed as a chirp sequence superimposed with target time delay and Doppler frequency shift.

[0024] It should be noted that the RD map, that is, the range-Doppler map, is a two-dimensional matrix. The horizontal axis (range dimension) maps the time delay to range bins through the beat frequency of the chirp, and the vertical axis (Doppler dimension) maps the velocity to Doppler bins through the phase change between chirps. The modulus value of each matrix element represents the reflection energy intensity of that range-velocity bin.

[0025] In specific implementation, the range and Doppler dimensional Fourier transforms can be performed on the radar echo signal, and non-coherent superposition processing can be performed on the multi-channel data, so as to obtain the RD map corresponding to the radar echo signal.

[0026] Step S20: Determine a candidate false target area in the RD map according to the radar frequency hopping characteristic and the bumper false target characteristic.

[0027] It should be noted that the speed calculation formula for the non-frequency hopping signal of the radar can be: speed = Vres * DopIdx. When speed (the speed of the target relative to the radar) approaches 0, the corresponding Doppler bin (DopIdx) also approaches 0 (as Figure 2 shown, the abscissa in the figure represents the range, and the ordinate represents the speed of the target relative to the radar), while for the frequency hopping signal of the radar, the speed calculation formula is: speed ≈ Vres * DopIdx - deltaf * R / (fc * Tc). It can be seen from the formula that the Doppler bin of the frequency hopping will be affected by the range bin where the target is located (as Figure 3 shown, the abscissa in the figure represents the range bin, and the ordinate represents the Doppler bin).

[0028] Based on the above formula, the Doppler bin of the frequency hopping signal can be deduced: DopIdx ≈ deltaf * N / B * - 2 * N * speed / ( * PRF). Therefore, the points determined to be bumper false targets need to meet condition 1 on the RD map: the range bin < rdxMax and condition 2: |DopIdx - deltaf * N / B * | < .

[0029] Among them, rdxMax is the maximum range threshold where the bumper false target may exist. Vres is the velocity resolution, deltaf is the frequency step between adjacent pulses, R = * Rres (range bin * range resolution), fc is the radar center frequency, Tc is the pulse repetition period, N is the number of pulses, B is the signal bandwidth of each pulse, is the wavelength of the transmitted signal, PRF is the pulse repetition frequency, is an integer approaching 0.

[0030] It can be understood that rdxMax can be determined according to historical experience, The corresponding adjustment can be made according to the speed measurement accuracy.

[0031] It should be understood that the bumper false target feature can include a generation mechanism, a spatial feature, a speed feature, an energy feature, and an inter-frame feature.

[0032] It should be noted that the generation mechanism of the bumper false target is that the electromagnetic wave penetrates the bumper and is reflected multiple times inside the crash beam or cavity, forming a false detection point. Therefore, the bumper false target has a spatial feature of being close to the radar and a speed feature of being relatively stationary to the radar, that is, the distance unit of the bumper false target is <rdxMax, and the speed (speed) relative to the radar approaches 0.

[0033] In addition, since the bumper false target is generally a false target formed by the radar sidelobe or backlobe irradiating into the vehicle body, the energy feature of the bumper false target is that the energy of the bumper false target is slightly weaker than that of the real target at the same distance. The inter-frame feature of the bumper false target is that the position and energy inter-frame height are consistent, and the motion randomness of the real target is lacking.

[0034] Since the bumper false target is generally a false target formed by the radar sidelobe or backlobe irradiating into the vehicle body, the energy of the detection point of this type will be slightly weaker than that of part of the real target, so condition 3: energy peakVal<peakThrMax can be set to filter the bumper false target and determine the candidate false target area. Wherein, peakThrMax represents the maximum value of the energy of the bumper false target, which can be set according to historical experience and dynamically adjusted according to the production line information to reduce the influence of the energy difference between different radars.

[0035] In a specific implementation, the maximum distance threshold can be determined based on the multiple reflection paths of the bumper; the Doppler shift amount is determined according to the speed calculation formula of the millimeter wave radar frequency hopping signal, and a Doppler threshold is set with the Doppler shift amount as the center; and the unit set in the RD diagram that satisfies the maximum distance threshold and the Doppler threshold is set as the candidate false target area.

[0036] It should be understood that the distance threshold is <rdxMax, and the Doppler shift amount is DopIdx-deltaf*N / B* , and the Doppler threshold is an interval, that is, | The cell set in the RD diagram satisfying the maximum distance threshold and the Doppler threshold is taken as a candidate false target region, that is, the cell set satisfying condition 1 and condition 2 is taken as a candidate false target region. In order to improve the accuracy of the candidate false target region, condition 3: energy peakVal < peakThrMax is set to screen the bumper false target, and the candidate false target region is further determined.

[0037] Step S30: An energy storage array is constructed based on the candidate false target region, and the energy storage array is initialized.

[0038] It should be noted that the energy storage array Dt is a one-dimensional table corresponding to the distance cells one by one, which is used to accumulate and update the energy statistical information of the candidate false target region between frames, and provide a historical reference for subsequent consistency checking.

[0039] It should be noted that the upper energy threshold and the lower energy threshold of the false target point can be determined according to the production line information and historical project experience values; the energy storage array is constructed based on the distance cell distribution of the candidate false target region; and the energy value corresponding to each distance cell in the energy storage array is initialized and assigned according to the upper energy threshold.

[0040] It should be understood that the production line information can refer to the consistency calibration data collected by the radar when it is offline in the mass production line. These data are used to give the energy upper and lower limit initial values that can cover the individual differences of the radar, so as to ensure that the same threshold script is applicable to all mass production vehicles.

[0041] Further, the historical project experience values can refer to the statistical results of large data collected on real roads by previously mass-produced vehicle models. The historical project experience values can also be used to correct the production line information, and further improve the rationality.

[0042] It should be explained that the distance cell distribution of the candidate false target region can refer to the range and density of the candidate false target region in the distance dimension. According to this distribution, the energy storage array needs to be established by distance cell by distance cell, and different initial energy thresholds are given to different distance cells, so as to match the objective law that the energy of the bumper false target decays with distance.

[0043] In a specific implementation, since the bumper false target is reflected back to the radar multiple times in the vehicle body, its energy will be slightly weaker than that of the real strong target point in the same distance segment. Here, the upper energy threshold peakThrMax and the lower energy threshold peakThrMIn of the energy of the bumper false target point can be determined in combination with the production line information and the historical project experience values. Dt[ ].peak = peakThrMax, where ​rdxMax), rdxMax represents the maximum distance unit.

[0044] Step S40: updating the energy storage array in real time, and performing energy and angle consistency checking on the points in the candidate false target region based on the energy storage array by using an inter-frame consistency checking mechanism, to obtain a checking result.

[0045] It should be understood that updating the energy storage array in real time can be storing the energy value peakVal in the energy storage array Dt in the current frame RD map under the condition 1 and the condition 2, i.e. Dt[ ].peak=peakVal[ , ], wherein each Doppler unit DopIdx changes with the distance and needs to satisfy the condition 2: |DopIdx-deltaf*N / B* |< . , which represents the Doppler unit corresponding to each distance unit of the bumper false target point. In short, the energy value of the bumper false target position in the candidate false target region in the current frame RD map is stored in the energy storage array Dt.

[0046] It should be noted that the energy information of each unit point in the candidate false target region in the current frame can be extracted, and the energy storage array is updated based on the energy information; the number of first units with energy greater than the energy lower threshold and the number of second units passing the constant false alarm detection (CFAR) in the energy storage array are counted; when the number of first units and the number of second units are greater than the first proportion threshold and the second proportion threshold respectively, the angle information of the current frame is written into the energy storage array.

[0047] In a specific line of sight, the number n0 (i.e. the number of first units) of units with energy greater than peakThrMIn and the number n1 (i.e. the number of second units) of units passing the constant false alarm detection (CFAR) in Dt[ ].peak are counted, if n0> *rdxMax (i.e. the first proportion threshold) and n1> *rdxMax (i.e. the second proportion threshold). Wherein, the value range is (0, 1) and peakThrMIn can be selected according to the historical minimum energy value of the bumper false target, , which represents the first frame collected by the radar under the ego motion scenario.

[0048] Understandably, writing the angle information of the current frame into the energy storage array can improve the accuracy of distinguishing between false and real targets on the bumper. The angle information can include azimuth information and its corresponding main-sidelobe ratio (the energy difference between the first and second peaks of the beammap). It should be noted that the same range Doppler cell may correspond to more than one angle, requiring multiple angles to be stored in the energy storage array. Dt[ ]. = [ ], Dt[ ]. = [ ], here [ ]、 [ The numbers represent the azimuth information and main lobe-side lobe ratio information corresponding to the distance of the false target on the bumper to the Doppler unit.

[0049] If the frame n0> *rdxMax, n1> *rdxMax, then it is considered that the first False target points for the bumper also exist on the RD map of the frame. Calculate the first... The mean value of peakVal at each distance unit in the previous frame and the frame is stored in the energy array Dt, i.e., Dt[ ].peak=[peakVal( )+peakVal( )] / 2, and update Dt with its corresponding multiple azimuth angles and main lobe-side lobe ratio information. In this context, i>0 represents any frame starting from frame 2 in the vehicle motion scene.

[0050] It should be understood that the inter-frame consistency check mechanism can refer to a set of rules that, across multiple consecutive frames, use historical statistical information from the same range cell (or range-Doppler cell) to determine the temporal consistency of energy, angle, and main-sidelobe ratio of candidate points in the current frame. Its core idea is that false targets on bumpers are generated by the fixed structure of the vehicle body, and their position, energy, and angular characteristics are highly stable across frames, while real targets exhibit significant inter-frame variations in these parameters due to relative motion or scattering fluctuations.

[0051] It should be noted that the step of using the inter-frame consistency check mechanism to perform energy and angle consistency checks on points within the candidate false target region based on the energy storage array to obtain the check result includes: extracting the target energy value and target angle information of points within the candidate false target region that have passed constant false alarm detection in the current frame; and setting the target energy value (peakVal[ , ]) and the historical average energy in the energy storage array (Dt[ The energy difference results are obtained by comparing the differences between -1]); the target angle information ( [ ]and [ ]) and the angle information (Dt[) of the corresponding distance unit in the energy storage array. ]. and Dt[ ]. The energy difference result and the angle difference result are compared with the energy threshold (C) and the angle threshold (C), respectively. and The results are compared and the verification result is determined based on the comparison.

[0052] It should be understood that the energy threshold (C) and the angle threshold (C) are different. and It can be adjusted according to the actual test values. and These are the comparison thresholds for inter-frame azimuth angle and main lobe-side lobe ratio, respectively.

[0053] It should be understood that the verification result is a binary (or confidence) judgment flag used to indicate whether the detected point in the current frame meets the inter-frame consistency criterion: if the energy difference result ≤ energy threshold C and the angle difference result ≤ angle threshold (ε and σ), the verification result is consistent (True), indicating that the point has typical inter-frame stability characteristics of a false target and can proceed to the subsequent marking process. If either threshold is exceeded, the verification result is inconsistent (False), indicating that the point has large inter-frame fluctuations and is judged as either a real target or noise, and is not marked as a false target.

[0054] Step S50: Mark the points in the verification results that satisfy the energy consistency verification and angle consistency verification as false target points, and perform suppression operations on the false target points.

[0055] In the specific implementation, if the first The peakVal value on the RD map corresponding to the distance between the false target and the frame bumper is shown. , ] <Dt[ -1]+C, and the first The azimuth angle and main-side lobe ratio of the false target on the frame bumper are approximately the same as the stored values. [ ]-Dt[ ]. |< If the points meet the energy consistency check and the angle consistency check, the points are considered to be false target points, and the false target points are marked and suppressed.

[0056] The embodiment discloses acquiring a radar echo signal, and generating an RD graph based on the radar echo signal; determining a candidate false target region in the RD graph according to radar frequency hopping characteristics and bumper false target characteristics; constructing an energy storage array based on the candidate false target region, and initializing the energy storage array; updating the energy storage array in real time, and performing energy and angle consistency checks on points in the candidate false target region based on the energy storage array by using an inter-frame consistency check mechanism to obtain a check result; and marking points in the check result that meet the energy consistency check and the angle consistency check as false target points, and performing a suppression operation on the false target points. Compared with the prior art, the embodiment improves the accuracy of distinguishing bumper false targets from real targets, and thus reduces the difficulty of suppressing bumper false targets.

[0057] Reference Figure 4 Figure 4 The figure is a flowchart of a second embodiment of the bumper false target suppression method of the millimeter wave radar.

[0058] Based on the first embodiment, in the embodiment, after the step S20, the steps S101-S102 are further included: Step S101: Acquire ego motion speed and a preset speed threshold, compare the ego motion speed with the preset speed threshold, and obtain a speed comparison result.

[0059] Step S102: When the speed comparison result indicates that the ego motion speed is greater than the preset speed threshold, perform the step of constructing an energy storage array based on the candidate false target region, and initializing the energy storage array.

[0060] It should be noted that when the ego is stationary, the bumper false target is easily mixed with the real stationary target on the road and cannot be distinguished. Here, in order to more conveniently screen, the working scene is set to the scene of ego motion, that is, egospeed. egospeed is ego speed information,​​​​​​ The preset speed threshold is determined according to Figure 2 The simulation results show that the preset speed threshold can be 5 in the embodiment The preset speed threshold can also be set according to historical experience and dynamically adjusted according to production line information to reduce the influence of energy differences between different radars.

[0061] In a specific implementation, when the speed comparison result indicates that the ego vehicle motion speed is greater than the preset speed threshold, that is, egospeed> threshold, the step of constructing the energy storage array based on the candidate false target region and initializing the energy storage array is performed. In a specific implementation, when the speed comparison result indicates that the ego vehicle motion speed is less than the preset speed threshold, that is, egospeed< threshold, the step of constructing the energy storage array based on the candidate false target region and initializing the energy storage array is performed.

[0062] The real stationary target and the bumper false target both present a zero-speed feature on the RD graph, and cannot be distinguished by speed, so the preset speed threshold is used to forcibly skip this scene, which can avoid misinitializing real targets such as roadside guardrails and stationary vehicles as statistical samples of bumper false targets, significantly reduce the false deletion rate, avoid missing detection of a target in front due to stationary false deletion, and meet the safety redundancy requirements of ADAS systems on functions such as emergency braking. Only when the ego vehicle is moving, the energy storage array is accumulated, which ensures that all samples in the database are bumper false targets formed by multiple reflections inside the vehicle body, makes the reference for subsequent inter-frame consistency verification purer, and improves the detection accuracy.

[0063] The ego vehicle motion speed and the preset speed threshold are obtained, and the ego vehicle motion speed is compared with the preset speed threshold to obtain a speed comparison result. When the speed comparison result indicates that the ego vehicle motion speed is greater than the preset speed threshold, the step of constructing the energy storage array based on the candidate false target region and initializing the energy storage array is performed. Since the energy storage array is constructed based on the candidate false target region when the ego vehicle motion speed is greater than the preset speed threshold, only when the ego vehicle is moving, the energy storage array is accumulated, which ensures that all samples in the database are bumper false targets formed by multiple reflections inside the vehicle body, makes the reference for subsequent inter-frame consistency verification purer, and improves the detection accuracy.

[0064] Referring to Figure 5 , Figure 5 is a flowchart of a third embodiment of the millimeter wave radar bumper false target suppression method.

[0065] Based on the above embodiments, in the present embodiment, the step S40 further includes steps S401-S403: ​Step S401: Extract the energy information of each unit point in the candidate false target area in the current frame, and update the energy storage array based on the energy information.

[0066] Step S402: Count the number of first units with energy greater than the energy lower threshold value and the number of second units passing the constant false alarm detection in the energy storage array.

[0067] Step S403: When the number of first units and the number of second units are respectively greater than the first ratio threshold and the second ratio threshold, increase the inter-frame presence count, and write the angle information of the current frame into the energy storage array.

[0068] It should be noted that the inter-frame presence count (cnt) is an integer variable used to record the cumulative number of times the candidate false target area is determined to be a suspected false target in multiple consecutive frames.

[0069] It can be understood that when the number of first units and the number of second units are respectively greater than the first ratio threshold and the second ratio threshold, increasing the inter-frame presence count reduces the probability of false alarms for real targets.

[0070] In a specific implementation, count the number n0 of energies greater than peakThrMIn in Dt .peak and the number n1 passing the constant false alarm detection (CFAR). If n0 > *rdxMax and n1 > *rdxMax, then the inter-frame bumper false target inter-frame presence count cnt + 1.

[0071] If for the th frame, n0 > *rdxMax, n1 > *rdxMax and cnt < Fmax, then it is considered that there are also bumper false target points on the RD map of the th frame, and the inter-frame bumper false target inter-frame presence count cnt + 1; if for the th frame, n0 < *rdxMax or n1 < *rdxMax, when cnt > 0, cnt - 1, otherwise cnt = 0. Here, Fmax is the maximum frame count value, which can be set according to the number of frames required for track confirmation.

[0072] Correspondingly, if for the th frame, the RD map characteristics satisfy n0 > *rdxMax and n1 > *rdxMax, and at this time cnt > *Fmax, then it is considered that for the The frame contains a false target for the bumper. Also, if the first... The peakVal value on the RD map corresponding to the distance between the false target and the frame bumper is shown. , ] <Dt[ -1]+C, and the first The azimuth angle and main-side lobe ratio of the false target on the frame bumper are approximately the same as the stored values. [ ]-Dt[ ]. |< , | [ ]-Dt[ ]. |< These points are considered suppressable bumper false targets and are marked for special processing by the tracking system. Here, the suppression of bumper false targets does not distinguish between the vehicle's motion state, but the update of the energy storage array Dt only occurs when the vehicle is moving. The value range of is (0,1). *Fmax is generally taken as an integer less than or equal to Fmax.

[0073] Accordingly, the step of marking the points in the verification results that satisfy the energy consistency verification and angle consistency verification as false target points and performing suppression operations on the false target points includes: obtaining the inter-frame presence count and determining the ratio of the inter-frame presence count to the maximum frame count value; when the ratio is greater than a preset ratio threshold, marking the points in the verification results that satisfy the energy consistency verification and angle consistency verification as false target points and performing suppression operations on the false target points.

[0074] This embodiment discloses the extraction of energy information from each unit point within the candidate false target region in the current frame, and updating the energy storage array based on the energy information; counting the number of first units with energy greater than the lower energy threshold and the number of second units passing constant false alarm rate (CFAR) detection in the energy storage array; when the number of first units and the number of second units are greater than a first proportional threshold and a second proportional threshold, respectively, the inter-frame presence count is increased, and the angle information of the current frame is written into the energy storage array. Because this embodiment increases the inter-frame presence count, it ensures the reliability of subsequent false target points.

[0075] In addition, the embodiment of the present application further provides a storage medium, wherein the storage medium stores a millimeter wave radar bumper false target suppression program, and the millimeter wave radar bumper false target suppression program is executed by a processor to realize the steps of the millimeter wave radar bumper false target suppression method.

[0076] Referring to Figure 6 , Figure 6 FIG. 1 is a structural block diagram of a millimeter wave radar bumper false target suppression device according to an embodiment of the present application.

[0077] As shown in Figure 6 , the millimeter wave radar bumper false target suppression device according to the embodiment of the present application comprises a signal processing model 601, a region determination module 602, an array construction module 603, an array update module 604 and a target suppression module 605.

[0078] The signal processing model 601 is configured to acquire a radar echo signal and generate an RD map based on the radar echo signal.

[0079] The region determination module 602 is configured to determine a candidate false target region in the RD map according to radar frequency hopping characteristics and bumper false target characteristics.

[0080] The array construction module 603 is configured to construct an energy storage array based on the candidate false target region and initialize the energy storage array.

[0081] The array update module 604 is configured to update the energy storage array in real time, perform energy and angle consistency verification on points in the candidate false target region based on the energy storage array by using an inter-frame consistency verification mechanism, and obtain a verification result.

[0082] The target suppression module 605 is configured to mark points in the verification result that meet the energy consistency verification and the angle consistency verification as false target points and perform a suppression operation on the false target points.

[0083] The region determination module 602 is further configured to determine a maximum distance threshold based on a bumper multiple reflection path, determine a Doppler offset based on a speed calculation formula of a millimeter wave radar frequency hopping signal, set a Doppler threshold with the Doppler offset as a center, and set a unit set in the RD map that meets the maximum distance threshold and the Doppler threshold as the candidate false target region.

[0084] The array construction module 603 is further configured to determine an upper energy threshold and a lower energy threshold of the false target point according to the production line information and historical project experience values, construct an energy storage array based on the distance cell distribution of the candidate false target region, and initialize and assign energy values corresponding to each distance cell in the energy storage array according to the upper energy threshold.

[0085] The device embodiment discloses acquiring a radar echo signal and generating an RD map based on the radar echo signal, determining a candidate false target region in the RD map according to radar frequency hopping characteristics and bumper false target characteristics, constructing an energy storage array based on the candidate false target region and initializing the energy storage array, updating the energy storage array in real time, performing energy and angle consistency checking on points in the candidate false target region based on the energy storage array by using an inter-frame consistency checking mechanism, obtaining a checking result, marking points in the checking result that meet energy consistency checking and angle consistency checking as false target points, and performing suppression operation on the false target points.

[0086] Based on the first embodiment of the millimeter wave radar bumper false target suppression device, the second embodiment of the millimeter wave radar bumper false target suppression device is proposed.

[0087] In the embodiment, the region determination module 602 is further configured to acquire a vehicle motion speed and a preset speed threshold, compare the vehicle motion speed with the preset speed threshold, and obtain a speed comparison result, and perform the steps of constructing the energy storage array based on the candidate false target region and initializing the energy storage array when the speed comparison result indicates that the vehicle motion speed is greater than the preset speed threshold.

[0088] Other embodiments or specific implementation manners of the millimeter wave radar bumper false target suppression device can refer to the above-mentioned method embodiments, and will not be described here.

[0089] The application provides a millimeter wave radar bumper false target suppression device, which comprises at least one processor and a memory connected with the at least one processor in communication; the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to perform the millimeter wave radar bumper false target suppression method in the above embodiment one.

[0090] Reference will be made to the following drawings to make the above and other aspects of the application more apparent. Figure 7 FIG. 1 shows a structural diagram of a millimeter wave radar bumper false target suppression device suitable for implementing embodiments of the application. The millimeter wave radar bumper false target suppression device in the embodiments of the application can include, but is not limited to, mobile terminals such as mobile phones, notebook computers, digital broadcast receivers, PDAs (Personal Digital Assistants), PADs (Portable Application Descriptions), PMPs (Portable Media Players), vehicle-mounted terminals (such as vehicle-mounted navigation terminals), and the like, as well as fixed terminals such as digital TVs, desktop computers, and the like. Figure 7 The millimeter wave radar bumper false target suppression device shown is merely an example and should not impose any limitations on the functions and use range of the embodiments of the application.

[0091] As Figure 7As shown, the millimeter wave radar bumper false target suppression device can include a processing device 1001 (e.g., a central processing unit, a graphics processing unit, etc.) that can perform various appropriate actions and processes according to programs stored in a read-only memory 1002 or programs loaded from a storage device 1003 into a random access memory 1004. Various programs and data required for the operation of the millimeter wave radar bumper false target suppression device are also stored in the random access memory 1004. The processing device 1001, the read-only memory 1002, and the random access memory 1004 are connected to each other through a bus 1005. An input / output interface 1006 is also connected to the bus. Generally, the following systems can be connected to the input / output interface 1006: input devices 1007 including, for example, a touch screen, a touch pad, a keyboard, a mouse, an image sensor, a microphone, an accelerometer, a gyroscope, etc.; output devices 1008 including, for example, a liquid crystal display (LCD), a speaker, a vibrator, etc.; the storage device 1003 including, for example, a magnetic tape, a hard disk, etc.; and a communication device 1009. The communication device 1009 can allow the millimeter wave radar bumper false target suppression device to communicate wirelessly or by wire with other devices to exchange data. Although the millimeter wave radar bumper false target suppression device with various systems is shown in the figure, it should be understood that all the systems shown are not required to be implemented or possessed. More or fewer systems can be alternatively implemented or possessed.

[0092] In particular, according to the embodiments disclosed in the present application, the processes described above with reference to the flowcharts can be implemented as a computer software program. For example, the embodiments disclosed in the present application include a computer program product comprising a computer program carried on a computer readable medium, the computer program containing program codes for executing the methods shown in the flowcharts. In such embodiments, the computer program can be downloaded and installed from a network through the communication device, or installed from the storage device 1003, or installed from the read-only memory 1002. When the computer program is executed by the processing device 1001, the above-mentioned functions defined in the methods of the embodiments disclosed in the present application are performed.

[0093] The millimeter wave radar bumper false target suppression device provided by the present application adopts the millimeter wave radar bumper false target suppression method in the above-mentioned embodiments, and can solve the technical problem that the existing technology has low accuracy in distinguishing bumper false targets from real targets, resulting in great difficulty in suppressing bumper false targets. Compared with the prior art, the millimeter wave radar bumper false target suppression device provided by the present application has the same beneficial effects as the millimeter wave radar bumper false target suppression method provided by the above-mentioned embodiments, and other technical features in the millimeter wave radar bumper false target suppression device are the same as the features disclosed in the previous embodiment method, which will not be repeated here.

[0094] It should be understood that portions of the application disclosed can be implemented in hardware, software, firmware, or combinations thereof. In the description of the embodiments above, specific features, structures, materials or characteristics can be combined in any suitable manner in one or more embodiments or examples.

[0095] The above description is merely illustrative of the application and is not intended to limit the scope of the application. Any variations and modifications of the embodiments described can be made without departing from the spirit of the present application, and such variations and modifications are also to be considered within the scope of the present application. Accordingly, the scope of protection of the present application is to be defined by the appended claims rather than the description.

[0096] It should be noted that the terms "comprising", "including", or any other variation thereof, are intended to cover a non-exclusive inclusion, such that processes, methods, articles, or systems that comprise a list of elements do not include only those elements recited, but can also include other elements not expressly listed or inherent to such processes, methods, articles, or systems. Without further limitation, an element preceded by "comprising" does not, without more limitations, foreclose the existence of additional identical elements in the process, method, article, or system that includes the recited element.

[0097] The above-mentioned embodiment numbers of the application are only for description and do not represent the advantages or disadvantages of the embodiments.

[0098] From the above description of the embodiments, those skilled in the art can clearly understand that the above-mentioned embodiment methods can be realized by means of software and necessary general hardware platforms, of course, they can also be realized by hardware, but in many cases the former is a better embodiment. Based on such understanding, the technical solutions of the present application can be embodied in the form of a software product, which is stored in a storage medium (such as a read-only memory / random access memory, a magnetic disk, an optical disk) and includes a number of instructions for making a terminal device (which can be a mobile phone, a computer, a server, an air conditioner, or a network device, etc.) execute the methods described in the various embodiments of the present application.

[0099] The above is only the preferred embodiment of the present application, and does not limit the patent scope of the present application, and any equivalent structure or equivalent process transformation made by using the content of the present application specification and drawings, or directly or indirectly applied to other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A method for suppressing false targets on a millimeter-wave radar bumper, characterized in that, The method includes: Acquire radar echo signals and generate an RD map based on the radar echo signals; Based on the radar frequency hopping characteristics and the features of the bumper as a false target, candidate false target regions are determined in the RD map; An energy storage array is constructed based on the candidate false target regions, and the energy storage array is initialized. The energy storage array is updated in real time, and the energy and angle consistency of the points in the candidate false target area are checked based on the energy storage array using the inter-frame consistency check mechanism to obtain the check result; Points in the verification results that satisfy both energy consistency verification and angle consistency verification are marked as false target points, and suppression operations are performed on the false target points.

2. The millimeter-wave radar bumper false target suppression method as described in claim 1, characterized in that, The step of determining candidate false target regions in the RD map based on radar frequency hopping characteristics and bumper false target features includes: The maximum distance threshold is determined based on the multiple reflection paths of the bumper. The Doppler offset is determined based on the velocity calculation formula of the millimeter-wave radar frequency hopping signal, and the Doppler threshold is set with the Doppler offset as the center. The set of cells in the RD graph that satisfy the maximum distance threshold and the Doppler threshold are selected as candidate false target regions.

3. The millimeter-wave radar bumper false target suppression method as described in claim 2, characterized in that, After the step of selecting the set of cells in the RD graph that satisfy the maximum distance threshold and the Doppler threshold as candidate false target regions, the method further includes: The vehicle's speed and a preset speed threshold are obtained, and the vehicle's speed is compared with the preset speed threshold to obtain a speed comparison result; When the speed comparison result indicates that the vehicle's speed is greater than the preset speed threshold, the steps of constructing an energy storage array based on the candidate false target region and initializing the energy storage array are executed.

4. The millimeter-wave radar bumper false target suppression method as described in claim 1, characterized in that, The step of constructing an energy storage array based on the candidate false target regions and initializing the energy storage array includes: Determine the upper and lower energy thresholds for false target points based on production line information and historical project experience values. An energy storage array is constructed based on the distance cell distribution of the candidate false target regions; The energy value corresponding to each distance unit in the energy storage array is initialized and assigned according to the energy upper limit threshold.

5. The millimeter-wave radar bumper false target suppression method as described in claim 4, characterized in that, The step of updating the energy storage array in real time includes: Extract the energy information of each unit point within the candidate false target region in the current frame, and update the energy storage array based on the energy information; Count the number of first units in the energy storage array whose energy is greater than the lower energy threshold and the number of second units that pass the constant false alarm rate (CFAR) detection. When the number of the first unit and the number of the second unit are greater than the first proportional threshold and the second proportional threshold, respectively, the inter-frame existence count is increased, and the angle information of the current frame is written into the energy storage array.

6. The millimeter-wave radar bumper false target suppression method as described in claim 5, characterized in that, The step of using the inter-frame consistency verification mechanism to perform energy and angle consistency verification on points within the candidate false target region based on the energy storage array and obtaining the verification result includes: Extract the target energy value and target angle information of points within the candidate false target region that have passed constant false alarm rate detection in the current frame; The target energy value is compared with the historical average energy value in the energy storage array to obtain the energy difference result; The target angle information is compared with the angle information of the corresponding distance unit in the energy storage array to obtain the angle difference result. The energy difference result and the angle difference result are compared with the energy threshold and the angle threshold, respectively, and the verification result is determined based on the comparison result.

7. The millimeter-wave radar bumper false target suppression method as described in claim 6, characterized in that, The step of marking points in the verification results that satisfy both energy consistency verification and angle consistency verification as false target points, and performing suppression operations on the false target points, includes: Obtain the inter-frame presence count and determine the ratio of the inter-frame presence count to the maximum frame count value; When the ratio is greater than a preset ratio threshold, the points in the verification results that satisfy both energy consistency verification and angle consistency verification are marked as false target points, and the false target points are suppressed.

8. A millimeter-wave radar bumper false target suppression device, characterized in that, The device includes: A signal processing model is used to acquire radar echo signals and generate RD maps based on the radar echo signals; The region determination module is used to determine candidate false target regions in the RD map based on radar frequency hopping characteristics and bumper false target features. An array construction module is used to construct an energy storage array based on the candidate false target regions and to initialize the energy storage array; The array update module is used to update the energy storage array in real time and use the inter-frame consistency verification mechanism to perform energy and angle consistency verification on the points in the candidate false target area based on the energy storage array to obtain the verification result. The target suppression module is used to mark points in the verification results that satisfy energy consistency verification and angle consistency verification as false target points, and to perform suppression operations on the false target points.

9. A millimeter-wave radar bumper false target suppression device, characterized in that, The device includes: a memory, a processor, and a millimeter-wave radar bumper false target suppression program stored in the memory and executable on the processor, the millimeter-wave radar bumper false target suppression program being configured to implement the steps of the millimeter-wave radar bumper false target suppression method as described in any one of claims 1 to 7.

10. A storage medium, characterized in that, The storage medium stores a millimeter-wave radar bumper false target suppression program, which, when executed by a processor, implements the steps of the millimeter-wave radar bumper false target suppression method as described in any one of claims 1 to 7.

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