Target detection method, system, chip and computer-readable storage medium

Abstract

The present application relates to a target detection method, system, chip and computer-readable storage medium. The method includes: a first transmission waveform and a second transmission waveform of a stepped linear frequency modulation continuous wave transmitted serially in each radar processing cycle; the center frequency change trends of the two continuous linear frequency modulation signals corresponding to the first transmission waveform and the second transmission waveform are opposite; the target reflection echo corresponding to each of the two waveforms is obtained, the first reflection echo is signal processed to obtain a first standard data set; the second reflection echo is signal processed to obtain a second standard data set without the stepping effect; the first standard data set and the second standard data set are combined and processed to obtain the point cloud related information of the actual detected target. The use of this method can solve the problem of missed detection of targets caused by spectrum overlap from the root.

Description

Technical Field

[0001] The present application relates to the field of radar technology, and in particular to a target detection method, system, chip and computer-readable storage medium. Background Art

[0002] With the popularization and development of intelligent driving technology in vehicles, the functions realized by ADAS (Advanced Driver Assistance System) are becoming more and more diverse, and the demand for the performance of vehicle-mounted millimeter-wave radar is also increasing. The main task of vehicle-mounted radar is to detect targets such as motor vehicles, non-motor vehicles and pedestrians in the detection area and estimate the distance, speed and angle information corresponding to the target.

[0003] In order to improve the resolution characteristics of the target in each dimension, a variety of technologies have been applied to the field of automotive radar, such as the use of MIMO (Multiple-Input Multiple-Output) technology to increase the virtual aperture and improve the angular resolution of the target.

[0004] However, for target detection scenarios, the relevant technologies lack technical solutions that can avoid missed target detection. Summary of the invention

[0005] Based on this, it is necessary to provide a target detection method, system, chip, computer device, computer-readable storage medium and computer program product that can avoid target omission in response to the above technical problems.

[0006] In a first aspect, the present application provides a target detection method, comprising:

[0007] Acquire a first reflected echo of a first transmitting waveform and a second reflected echo of a second transmitting waveform; wherein the first transmitting waveform and the second transmitting waveform are stepped linear frequency modulation continuous waves transmitted in series in each radar processing cycle; and the center frequency change trends of two continuous linear frequency modulation signals corresponding to the first transmitting waveform and the second transmitting waveform are opposite;

[0008] Performing signal processing on the first reflected echo to obtain a first standard data set without stepping effects; the first standard data set includes information related to a first point cloud reflecting the first transmitted waveform;

[0009] Performing signal processing on the second reflected echo to obtain a second standard data set without stepping effects; the second standard data set includes information related to a second point cloud reflecting the second transmitted waveform;

[0010] The first standard data set and the second standard data set are processed together to obtain point cloud information of the actually detected target.

[0011] In one embodiment, the performing signal processing on the first reflected echo to obtain a first standard data set with stepping effect removed includes:

[0012] Performing signal processing on the first reflected echo to obtain a first digital signal of the first reflected echo in a current radar processing cycle;

[0013] After sampling and coherent accumulation of the first digital signal in a fast time sampling dimension and a slow time sampling dimension, and incoherent accumulation between receiving channels, a first spectrum heat map of a current radar processing cycle is obtained;

[0014] Performing target detection processing on the first spectrum heat map to obtain a first data set;

[0015] The first data set is standardized to obtain a first standard data set with step effect removed.

[0016] In one embodiment, the first point cloud related information includes a radial distance index value and a radial relative speed index value, and the first data set is standardized to obtain a first standard data set without stepping effect, including:

[0017] Acquire a first waveform parameter of the first transmit waveform;

[0018] For each detection point in the first data set, determine a radial relative velocity index change value according to the radial distance index value of each detection point and the first waveform parameter; wherein the radial relative velocity index change value is used to characterize the change of the radial relative velocity index value caused by using the first transmission waveform;

[0019] Standardizing the radial relative velocity index value according to the radial relative velocity index change value to obtain a standardized radial relative velocity index value using a standard linear frequency modulation waveform;

[0020] A first standard data set with stepping effect removed is obtained according to the standardized radial relative velocity index value and the radial distance index value.

[0021] In one embodiment, the step of normalizing the radial relative velocity index value according to the radial relative velocity index change value to obtain a normalized radial relative velocity index value using a standard linear frequency modulation waveform includes:

[0022] Determine a first relationship satisfied among the radial relative velocity index change value, the radial relative velocity index value of each detection point, and the standard radial relative velocity index value;

[0023] Based on the first relationship, the radial relative velocity index value of each detection point in the first data set is standardized using the radial relative velocity index change value to obtain a standardized radial relative velocity index value using a standard linear frequency modulation waveform.

[0024] In one embodiment, the first waveform parameters include a center frequency difference between two consecutive linear frequency modulation signals in the first transmit waveform, the number of linear frequency modulation signals included in the first transmit waveform, and a sweep bandwidth of the linear frequency modulation signal.

[0025] The step of determining, for each detection point in the first data set, a radial relative velocity index change value according to the radial distance index value of the detection point and the first waveform parameter, comprises:

[0026] Determining the product of the number of signals and the center frequency difference;

[0027] The ratio of the product to the frequency sweep bandwidth is multiplied by the radial distance index value of each of the detection points, and the obtained product is determined as the radial relative velocity index change value.

[0028] In one embodiment, based on the first relationship, the radial relative velocity index value of each detection point is normalized using the radial relative velocity index change value to obtain a normalized radial relative velocity index value using a standard linear frequency modulation waveform, including:

[0029] Based on the first relationship, the radial relative velocity index value is standardized by determining the difference between the radial relative velocity index value and the radial relative velocity index change value of each detection point to obtain a standardized radial relative velocity index value using a standard linear frequency modulation waveform.

[0030] In one embodiment, the performing signal processing on the second reflected echo to obtain a second standard data set with the step effect removed includes:

[0031] Performing signal processing on the second reflected echo to obtain a second digital signal of the second transmitting waveform in a current radar processing cycle;

[0032] After sampling and coherent accumulation of the second digital signal in a fast time sampling dimension and a slow time sampling dimension, and incoherent accumulation between receiving channels, a second spectrum heat map of the current radar processing cycle is obtained;

[0033] Performing target detection processing on the second spectrum heat map to obtain a second data set;

[0034] The second data set is standardized to obtain a second standard data set with the step effect removed.

[0035] In a second aspect, the present application further provides a radar system, the radar system comprising a transmitting antenna, a receiving antenna and a signal processing module, wherein:

[0036] The transmitting antenna is used to transmit a first transmitting waveform and a second transmitting waveform in series during a radar processing cycle, wherein the first transmitting waveform and the second transmitting waveform are both stepped linear frequency modulation continuous waves; and the center frequency change trends of two continuous linear frequency modulation signals corresponding to the first transmitting waveform and the second transmitting waveform are opposite;

[0037] The receiving antenna is used to receive a first reflected echo of a first transmitted waveform and a second reflected echo of a second transmitted waveform;

[0038] The signal processing module is used to perform signal processing on the first reflected echo to obtain a first standard data set with stepping effects removed; the first standard data set includes first point cloud related information reflecting the first transmitted waveform; perform signal processing on the second reflected echo to obtain a second standard data set with stepping effects removed; the second standard data set includes second point cloud related information reflecting the second transmitted waveform; and perform a combined processing on the first standard data set and the second standard data set to obtain point cloud information of the overall detected target.

[0039] In a third aspect, the present application further provides a chip, including a memory and a processor, wherein the memory stores a computer program, and when the processor executes the computer program, the following steps are implemented:

[0040] Acquire a first reflected echo of a first transmitting waveform and a second reflected echo of a second transmitting waveform; wherein the first transmitting waveform and the second transmitting waveform are stepped linear frequency modulation continuous waves transmitted in series in each radar processing cycle; and the center frequency change trends of two continuous linear frequency modulation signals corresponding to the first transmitting waveform and the second transmitting waveform are opposite;

[0041] Performing signal processing on the first reflected echo to obtain a first standard data set without stepping effects; the first standard data set includes information related to a first point cloud reflecting the first transmitted waveform;

[0042] Performing signal processing on the second target reflected echo to obtain a second standard data set without stepping effect; the second standard data set includes information related to a second point cloud reflecting the second transmitted waveform;

[0043] The first standard data set and the second standard data set are processed together to obtain point cloud information of the entire detected target.

[0044] In a fourth aspect, the present application further provides a computer-readable storage medium having a computer program stored thereon, wherein when the computer program is executed by a processor, the following steps are implemented:

[0045] Acquire a first reflected echo of a first transmitting waveform and a second reflected echo of a second transmitting waveform; wherein the first transmitting waveform and the second transmitting waveform are stepped linear frequency modulation continuous waves transmitted in series in each radar processing cycle; and the center frequency change trends of two continuous linear frequency modulation signals corresponding to the first transmitting waveform and the second transmitting waveform are opposite;

[0046] Performing signal processing on the first reflected echo to obtain a first standard data set without stepping effects; the first standard data set includes information related to a first point cloud reflecting the first transmitted waveform;

[0047] Performing signal processing on the second reflected echo to obtain a second standard data set without stepping effects; the second standard data set includes information related to a second point cloud reflecting the second transmitted waveform;

[0048] The first standard data set and the second standard data set are processed together to obtain point cloud information of the actually detected target.

[0049] In a fifth aspect, the present application further provides a computer program product, including a computer program, which implements the following steps when executed by a processor:

[0050] Acquire a first reflected echo of a first transmitting waveform and a second reflected echo of a second transmitting waveform; wherein the first transmitting waveform and the second transmitting waveform are stepped linear frequency modulation continuous waves transmitted in series in each radar processing cycle; and the center frequency change trends of two continuous linear frequency modulation signals corresponding to the first transmitting waveform and the second transmitting waveform are opposite;

[0051] Performing signal processing on the first reflected echo to obtain a first standard data set without stepping effects; the first standard data set includes information related to a first point cloud reflecting the first transmitted waveform;

[0052] Performing signal processing on the second reflected echo to obtain a second standard data set without stepping effects; the second standard data set includes information related to a second point cloud reflecting the second transmitted waveform;

[0053] The first standard data set and the second standard data set are processed together to obtain point cloud information of the entire detected target.

[0054] The target detection method, system, chip, computer-readable storage medium and computer program product transmit two different stepped linear frequency modulation continuous waves in series during a radar processing cycle, and the center frequency change trends of the two continuous linear frequency modulation signals are opposite. Based on receiving the first reflected echo and the second reflected echo reflected by the two different stepped linear frequency modulation continuous waves, the first reflected echo and the second reflected echo are respectively processed to remove the stepping effect, and converted into the first standard data set and the second standard data set under the standard linear frequency modulation waveform. This processing method ensures the standardization of the speed index. On this basis, the first standard data set and the second standard data set are obtained. The point cloud related information of the detected target is obtained by processing, and the target detection is performed by serially transmitting two different stepped linear frequency modulation continuous waves in the radar processing cycle. Even if the radial distance and relative speed of the target are similar, each target can be effectively detected, and the missed detection caused by the overlap of the echo signal spectrum can be avoided. In other words, this method can not only ensure the radial distance resolution capability of the target, but also reduce the problem of missed detection of a certain target due to spectrum overlap; further, by changing the stepped linear frequency modulation waveform emission mechanism and the corresponding echo signal processing, the target located in the overlapping spectrum area can be detected from the root, which effectively solves the missed detection problem. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] In order to more clearly illustrate the technical solutions in the embodiments of the present application or related technologies, the drawings required for use in the embodiments of the present application or related technical descriptions will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0056] Figure 1 A schematic diagram of target detection results in one embodiment;

[0057] Figure 2 A schematic diagram of target detection results in another embodiment;

[0058] Figure 3 A diagram showing an application environment of a target detection method in an embodiment;

[0059] Figure 4 Schematic diagram of a target detection method in one embodiment;

[0060] Figure 5 is a flow chart of step 404 in one embodiment;

[0061] Figure 6 is a schematic diagram of a flow chart of step 406 in one embodiment;

[0062] Figure 7 is a flow chart of a target detection method in another embodiment;

[0063] Figure 8 is a schematic diagram of a first spectrum heat map in one embodiment;

[0064] Fig. 9 is a schematic diagram of a second spectrum heat map in one embodiment;

[0065] Fig.10 is a schematic diagram of a first spectrum heat map in another embodiment;

[0066] Fig.11 is a schematic diagram of a second spectrum heat map in another embodiment;

[0067] Fig.12 A schematic diagram of a graph showing a change in spectrum echo energy versus radial relative velocity index value in one embodiment;

[0068] Fig.13 is a structural block diagram of a radar system in one embodiment;

[0069] Fig.14 FIG. 4 is a diagram showing the internal structure of a chip in one embodiment. DETAILED DESCRIPTION

[0070] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0071] The main task of vehicle-mounted radar is to detect targets in the detection area, such as motor vehicles, non-motor vehicles and pedestrians, and estimate the corresponding distance, speed and angle information of the targets. In order to improve the resolution characteristics of each dimension of the target, a variety of technologies have been applied to the field of vehicle-mounted radar, such as the use of MIMO technology to increase the virtual aperture to improve the angular resolution of the target, and the use of stepped linear frequency modulation continuous waveform to improve the radial distance resolution of the target. The use of stepped linear frequency modulation waveform is beneficial to improving the radial distance resolution of the target, especially for two targets with similar radial distances and the same radial relative speed. By using a stepped linear frequency modulation waveform, the two targets can be distinguished from the radial relative velocity dimension, thereby improving the radial distance resolution of the target, such as Figure 1 As shown, there are target 1 and target 2, and target 1 and target 2 can be distinguished using a stepped linear frequency modulation waveform.

[0072] However, the driving environment of vehicles is complex. If there is a third target in the scene with two targets, and its radial distance and radial relative speed are close to the above two targets, for example, there is a non-motor vehicle scene with low speed movement next to a stationary object, such as a low-speed vehicle or pedestrian next to a fence, using a stepped linear frequency modulation waveform will cause the third target to overlap with one of the above two targets in the spectrum, which will eventually lead to the third target being missed. Figure 2 As shown, target 3 is close to target 1 and target 2 in radial distance, and the radial relative speed of target 3 is close to target 1 and target 2. The related art uses a stepped linear frequency modulation waveform, which makes it impossible to distinguish target 1 and target 3, thereby causing target miss detection. Figure 1 and Figure 2 The horizontal axis represents the radial distance index value, the vertical axis represents the relative velocity index value, R_res represents the radial distance resolution, and V_res represents the radial relative velocity resolution.

[0073] It should be noted that close distance can be understood as the distance between the two targets being less than the index of distance resolution, and similar speed cannot be specifically quantified, but can be understood as being determined according to system parameters, waveform parameters, distance index values, etc. The number of third targets can be one or more, and the number of third targets is taken as one for illustration.

[0074] In view of the above-mentioned missed detection problem caused by the overlap of the spectrum of the approximate radial relative velocity target, a target detection method is proposed. This method transmits two different stepped linear frequency modulation waveforms in series within the frame period in the ramp generator of the vehicle-mounted radar chip, and the center frequency change trends of the two continuous linear frequency modulation signals corresponding to the two waveforms are opposite. By serially transmitting two different stepped linear frequency modulation continuous waves in the radar processing period, target detection is performed, which can process the echo of each waveform and reduce the problem of missed detection of a target in the environment due to spectrum overlap.

[0075] The target detection method provided in the embodiments of the present application can be applied to, but is not limited to, Figure 3 In the application environment shown. Among them, a radar 304 is deployed on the mobile carrier 302. The radar 304 can be but not limited to different types of vehicle-mounted millimeter wave radars. The deployment position of the radar can be set according to actual needs. Figure 3The radar shown in is for illustration only. The mobile carrier 302 may be a vehicle-mounted platform, such as a car, motorcycle or bicycle. Alternatively, the mobile carrier 302 may be a ship-mounted platform, such as a ship, a ship, a motorboat, etc. Alternatively, the mobile carrier 302 may be a vehicle-mounted platform or an airborne platform, such as a drone, a helicopter or a jet, a balloon, etc. When the mobile carrier 302 is a vehicle, the vehicle-mounted millimeter-wave radar may detect objects in the detection area, and the objects in the detection area may be, but are not limited to, stationary objects and / or moving objects, stationary objects may be, but are not limited to, curbs, fences and traffic lights, etc., and moving objects may be, but are not limited to, pedestrians, motor vehicles and non-motor vehicles, etc. The data storage system may store data that the mobile carrier 302 needs to process. The data storage system may be integrated on the mobile carrier 302, or may be placed on a cloud server or other network server.

[0076] In an exemplary embodiment, Figure 4 As shown, a target detection method is provided, which is applied to Figure 1 The application environment in FIG. 1 is taken as an example to illustrate, including the following steps 402 to 408. Among them:

[0077] Step 402, obtaining a first reflected echo of a first transmitting waveform and a second reflected echo of a second transmitting waveform; wherein the first transmitting waveform and the second transmitting waveform are stepped linear frequency modulation continuous waves transmitted serially in each radar processing cycle; and the center frequency change trends of two continuous linear frequency modulation signals corresponding to the first transmitting waveform and the second transmitting waveform are opposite.

[0078] Among them, the first reflected echo is a superposition wave of echoes of multiple targets based on the reflection of the first transmitting waveform, and the second reflected echo is a superposition wave of echoes of multiple targets based on the reflection of the second transmitting waveform. The first transmitting waveform and the second transmitting waveform are transmitted by the ramp generator of the on-board radar chip. The radar system corresponding to the on-board radar chip includes K transmitting antennas and L receiving antennas. K and L are positive integers, and the number of K and L is not limited here. The radar system can be a MIMO radar system. In the MIMO radar system, various multiple access technologies such as time division multiple access (TDMA), frequency division multiple access (FDMA) and Doppler division multiple access (DDMA) can be applied. In the first transmitting waveform, the frequency modulation slope of each linear frequency modulation signal is expressed by The sweep bandwidth of each linear frequency modulation signal is expressed as Each linear frequency modulation signal contains A fast time sampling, that is m = 0...M1-1, and the transmission waveform cycle contains A linear frequency modulation signal, The radar system uses a stepped linear frequency modulation continuous waveform to ensure the high radial range resolution of the target. Accordingly, the center frequency difference between two continuous linear frequency modulation signals is expressed as The center frequency is expressed as It should be noted that the fast time sampling dimension and the slow time sampling dimension may correspond to the radial distance dimension and the radial relative velocity dimension.

[0079] In the second transmission waveform, the frequency modulation slope of each linear frequency modulation signal is expressed as The sweep bandwidth of each linear frequency modulation signal is expressed as Each linear frequency modulation signal contains A fast time sampling, that is , and the emission waveform period contains A linear frequency modulation signal, The radar system uses a stepped linear frequency modulation continuous waveform to ensure the high radial range resolution of the target. Accordingly, the center frequency difference between two continuous linear frequency modulation signals is expressed as The center frequency is expressed as It should be noted that the center frequency difference between the two continuous linear frequency modulation signals corresponding to the first transmission waveform and the second transmission waveform has opposite signs.

[0080] Furthermore, there is a time interval between the absolute emission time cutoff of the first emission waveform and the absolute emission time start of the second emission waveform, so as to ensure that the target reflection echo corresponding to the first emission waveform and the target reflection echo corresponding to the second emission waveform can be distinguished within the same radar processing cycle. The center frequency change trends of the two continuous linear frequency modulation signals corresponding to the waveform parameters of the first emission waveform and the second emission waveform are opposite, and the center frequency difference of the two continuous linear frequency modulation signals can at least keep the opposite signs, or the difference can be the same or different on the basis of keeping the opposite signs. Other waveform parameters for the first emission waveform and the second emission waveform can be determined according to actual needs and are not limited here.

[0081] For example, a radar system including one transmitting antenna and one receiving antenna is used as an example to explain that two groups of stepped linear frequency modulation continuous waves are serially transmitted in each radar processing cycle, which are respectively recorded as the first transmitting waveform and the second transmitting waveform. The target reflection echoes corresponding to the first transmitting waveform and the second transmitting waveform are received by the radar receiver, that is, the first reflection echo of the first transmitting waveform and the second reflection echo of the second transmitting waveform are obtained. Among them, the first reflection echo and the second reflection echo can be the superposition of the echoes of multiple targets reflected back by the corresponding transmitting waveforms of each group after encountering the target.

[0082] Step 404 , performing signal processing on the first reflected echo to obtain a first standard data set with the stepping effect removed; the first standard data set includes first point cloud related information obtained based on the echo corresponding to the first transmitting waveform.

[0083] Among them, the first point cloud related information includes the radial distance index value and the radial relative velocity index value of the detection point associated with the echo corresponding to the first transmission waveform. The first standard data set can be a data set formed based on the radial distance index value and the radial relative velocity index value, or a data set formed based on the radial distance and the radial relative velocity. Here, the first standard data set is not specifically limited. It can be understood that the radial distance and the radial relative velocity can be obtained by converting the radial distance index value and the radial relative velocity index value based on the first transmission waveform parameters. The conversion method can be an interpolation method or an existing method, which will not be repeated here. The interpolation method can be to obtain the corresponding radial distance and radial relative velocity by parabolic interpolation. This method can improve the accuracy of radial distance estimation and radial relative velocity estimation.

[0084] It can be understood that the first reflected echo is determined based on a stepped linear frequency modulation continuous wave. Therefore, compared with the use of a standard linear frequency modulation waveform, since the center frequency of each linear frequency modulation signal has a step, this nonlinear frequency change may change the relationship between the Doppler frequency and the velocity index value, resulting in a change in the velocity index value, that is, the radial relative velocity index value corresponding to the target will change. In order to improve the radar system's ability to resolve targets, it is necessary to convert the first data set containing the detected target (i.e., the detection point) into a first standard data set. Converting the first data set into the first standard data set can eliminate the stepping effect on the radial relative velocity index value.

[0085] Exemplarily, the first reflected echo is received by a radar receiver, and then passes through a mixer, a low-pass filter, an amplifier, and an analog-to-digital converter to determine a digital signal of the first transmitting waveform in the current radar processing cycle, the digital signal is sampled and processed and discrete Fourier transformed (or a corresponding fast algorithm in engineering implementation) to obtain a first frequency spectrum heat map of the current radar processing cycle, target detection is performed on the first frequency spectrum heat map to obtain point cloud information of the detected target, that is, a first data set is obtained, the first data set is converted to a standard linear frequency modulation waveform to obtain a corresponding first standard data set.

[0086] Step 406 , performing signal processing on the second reflected echo to obtain a second standard data set with the stepping effect removed; the second standard data set includes second point cloud related information obtained based on the echo corresponding to the second transmission waveform.

[0087] Among them, the second point cloud related information includes the radial distance index value and the radial relative velocity index value of the detection point associated with the echo corresponding to the second transmission waveform. The second standard data set can be a data set formed based on the radial distance index value and the radial relative velocity index value, or a data set formed based on the radial distance and the radial relative velocity. Here, the second standard data set is not specifically limited. It can be understood that the radial distance and the radial relative velocity can be obtained by converting the radial distance index value and the radial relative velocity index value based on the second transmission waveform parameters. The conversion method can be an interpolation method or an existing method, which will not be repeated here. The interpolation method can be to obtain the corresponding radial distance and radial relative velocity by parabolic interpolation. This method can improve the accuracy of radial distance estimation and radial relative velocity estimation.

[0088] It can be understood that the second reflected echo is determined based on a stepped linear frequency modulation continuous wave. Therefore, compared with the use of a standard linear frequency modulation waveform, since the center frequency of each linear frequency modulation signal has a step, this nonlinear frequency change may change the relationship between the Doppler frequency and the velocity index value, resulting in a change in the velocity index value, that is, the radial relative velocity index value corresponding to the target will change. In order to improve the radar system's ability to resolve targets, it is necessary to convert the second data set containing the detected target into a second standard data set. Converting the second data set into the second standard data set can eliminate the stepping effect on the radial relative velocity index value.

[0089] Exemplarily, the second reflected echo is received by the radar receiver, and then passes through a mixer, a low-pass filter, an amplifier and an analog-to-digital converter to determine the digital signal of the second transmission waveform in the current radar processing cycle, and the digital signal is sampled and processed and discrete Fourier transformed (or a corresponding fast algorithm in engineering implementation) to obtain a second frequency spectrum heat map of the current radar processing cycle, and target detection is performed on the second frequency spectrum heat map to obtain point cloud information of the detected target, that is, a second data set is obtained, and the second data set is converted to a standard linear frequency modulation waveform to obtain a corresponding second standard data set.

[0090] Step 408 , the first standard data set and the second standard data set are processed together to obtain point cloud related information of the entire detected target.

[0091] For example, the first standard data set and the second standard data set are combined and processed to obtain the final target standard data set, that is, the point cloud information of the detected target as a whole can be obtained. Based on this final target standard data set, the radial distance and radial relative velocity can be solved and the subsequent radar signal processing process can be executed. The subsequent radar signal processing process includes but is not limited to target tracking and target identification and estimation of relevant parameters of the target.

[0092] In the above target detection method, two different stepped linear frequency modulation continuous waves are serially transmitted in a radar processing cycle, and the center frequency change trends of the two continuous linear frequency modulation signals are opposite. Based on receiving the first reflected echo and the second reflected echo reflected by the two different stepped linear frequency modulation continuous waves, the first reflected echo and the second reflected echo are respectively processed to remove the stepping effect, and converted into the first standard data set and the second standard data set under the standard linear frequency modulation waveform. This processing method ensures the standardization of the speed index. On this basis, the obtained first standard data set and the second standard data set are combined and processed to obtain the point cloud information of the overall detected target. In the method of serially transmitting two different stepped linear frequency modulation continuous waves in the radar processing cycle, target detection is performed. Even if the radial distance and radial relative speed of the target are similar, the missed detection problem caused by the aliasing of the spectrum of the single stepped linear frequency modulation waveform can be avoided. That is to say, this method can not only ensure the radial distance resolution capability of the target, but also reduce the problem of missed detection of one of the targets due to spectrum overlap; further, this method of changing the stepped linear frequency modulation waveform allows the target located in the overlapping spectrum area to be detected from the root, effectively solving the missed detection problem.

[0093] The above target detection method involves the conversion of data sets. In an exemplary embodiment, Figure 5 As shown, step 404 includes steps 502 to 510. Among them:

[0094] Step 502: Perform signal processing on the first reflected echo to obtain a first digital signal of the first transmit waveform in the current radar processing cycle.

[0095] It can be understood that the first reflected echo can be determined based on the above-mentioned first transmitted waveform, then the target reflected echo is received by the radar receiver, and then passes through the mixer, low-pass filter, amplifier and analog-to-digital converter to determine the first digital signal of the first transmitted waveform in the current radar processing cycle. .

[0096] Step 504 , after sampling and coherent accumulation of the first digital signal in the fast time sampling dimension and the slow time sampling dimension and incoherent accumulation between receiving channels, a first spectrum heat map of the current radar processing cycle is obtained.

[0097] Exemplarily, based on the first digital signal of the first transmit waveform in the current radar processing cycle , after sampling and coherent accumulation in the fast time and slow time sampling dimensions and incoherent accumulation between receiving channels, i.e. radial distance dimension and radial relative velocity dimension, discrete Fourier transform (or its corresponding fast algorithm in engineering implementation) is used to obtain the first spectrum heat map of the current radar processing cycle, which is recorded as , the method for determining the first spectrum heat map is not limited here.

[0098] Step 506: Perform target detection processing on the first spectrum heat map to obtain first point cloud related information obtained based on the echo corresponding to the first transmission waveform.

[0099] For example, for the first spectrum heat map The target detection algorithm is used to obtain the target radial distance index value and the target radial relative speed index value, and P is used to represent the spectrum heat map based on the first transmission waveform. The number of target detections in the current radar processing cycle, i.e., the first quantity. The target detection algorithm may be, but is not limited to, CA-CFAR, OS-CFAR, etc. and a strategy combining local peak selection to determine the final radial distance index value and radial relative velocity index value of the target. This application does not make any unnecessary elaboration or selection restrictions on this. The first data set includes the radial distance index value and radial relative velocity index value corresponding to each detection point.

[0100] Step 508: Determine a first data set according to the first point cloud related information.

[0101] The first point cloud related information includes point cloud related information of multiple detection points, and the point cloud related information of each detection point includes a radial distance index value and a radial relative speed index value.

[0102] For example, the radial distance index value corresponding to each detection point is and radial relative velocity index , determine the first data set .

[0103] Step 510: Standardize the first data set to obtain a first standard data set with the step effect removed.

[0104] The standardization of the first data set can be understood as converting the first data set to a standard linear frequency modulation waveform to obtain a first standard data set under a standard linear frequency modulation waveform. Optionally, the change in the target radial relative velocity index value caused by the first transmission waveform in the first data set can be eliminated.

[0105] It should be noted that due to the use of step-by-step linear frequency modulation waveform, the original two radial distances are close (the radial distance difference is less than the distance resolution). ) and targets with the same radial relative speed can be distinguished in the radial relative speed dimension to ensure the resolution of the target's radial distance. However, at the same time, compared with the use of a standard linear frequency modulation waveform, the radial relative speed index value corresponding to the target will change. This change is determined by the radial distance index value of the target, the center frequency difference of two consecutive linear frequency modulation signals, and the radial distance index value of the target. , and the number of linear frequency modulation signals contained in the first transmission waveform The radial relative velocity index change value can be expressed as: .

[0106] Exemplarily, by eliminating the change in the target radial relative velocity index value caused by the first transmission waveform in the first data set, the first data set is standardized to obtain a first standard data set with the step effect removed.

[0107] In the above embodiment, the change in the radial relative velocity index value caused by using the first transmitting waveform is determined based on the radial distance index value of the target, the difference in center frequencies of two consecutive linear frequency modulation signals, and the number of linear frequency modulation signals contained in the first transmitting waveform. Based on this change, the determined first data set is converted to obtain a corresponding first standard data set for subsequent signal processing to extract relevant information of the overall point cloud.

[0108] Optionally, in an exemplary embodiment, a method for standardizing a first data set is provided, including: for each detection point in the first data set, determining a radial relative velocity index change value based on the radial distance index value of the detection point and a first waveform parameter; wherein the radial relative velocity index change value is used to characterize the change in the target radial relative velocity index value caused by using the first transmitting waveform; standardizing the radial relative velocity index value based on the radial relative velocity index change value to obtain a standardized radial relative velocity index value using a standard linear frequency modulation waveform; and obtaining a first standard data set with stepping effects removed based on the standardized radial relative velocity index value and the radial distance index value.

[0109] The first waveform parameter includes but is not limited to the center frequency difference between two consecutive linear frequency modulation signals in the first transmitting waveform. , the number of linear frequency modulation signals included in the first transmission waveform , and the sweep bandwidth of the linear FM signal .

[0110] The radial relative velocity index change value can be determined, but not limited to, based on the radial distance index value and the first waveform parameter, and can also be implemented according to existing methods. The implementation method of determining the radial distance index value and the first waveform parameter includes: determining the product of the number of signals and the center frequency difference; multiplying the ratio of the product to the sweep bandwidth with the radial distance index value of each detection point in the first data set, and determining the obtained product as the radial relative velocity index change value, that is, the change is determined by the radial distance index value of the target, the center frequency difference of two continuous linear frequency modulation signals, and the radial distance index value of each detection point in the first data set. , and the number of linear frequency modulation signals contained in the first transmission waveform Optionally, the radial relative velocity index change value can be expressed as: .

[0111] Standardizing the radial relative speed index value according to the radial relative speed index change value can be understood as subtracting the radial relative speed index change value from the radial relative speed index value, that is, eliminating the step effect. Specifically, it can be expressed as: determining the first relationship satisfied between the radial relative speed index change value, the radial relative speed index value of each detection point, and the standard radial relative speed index value; based on the first relationship, using the radial relative speed index change value to standardize the radial relative speed index value of each first target, and obtain a standardized radial relative speed index value under the standard linear frequency modulation waveform. The first relationship can be expressed as:

[0112] ;

[0113] in, represents the radial relative velocity index value obtained using a standard linear frequency modulation waveform;

[0114] On this basis, based on the first relationship, by determining the difference between the radial relative velocity index value and the radial relative velocity index change value of each detection point, the radial relative velocity index value is standardized to obtain a standardized radial relative velocity index value under a standard linear frequency modulation waveform. The difference between the radial relative velocity index value and the radial relative velocity index change value can be expressed as: According to the standardized radial relative velocity index value and the radial distance index value, a first standard data set with the step effect removed is obtained. The first standard data set can be expressed as: ,

[0115] Among them, mod represents the modulus operation of the signal, and then the spectral characteristics of the signal are adjusted according to a specific modulation method. The above method can be used to extract the relevant information of the overall point cloud in subsequent signal processing.

[0116] In an exemplary embodiment, Figure 6 As shown, step 406 includes steps 602 to 610. Among them:

[0117] Step 602: Perform signal processing on the second reflected echo to obtain a second digital signal of the second transmit waveform in the current radar processing cycle.

[0118] Step 604 , after sampling and coherent accumulation of the second digital signal in the fast time sampling dimension and the slow time sampling dimension and incoherent accumulation between receiving channels, a second spectrum heat map of the current radar processing cycle is obtained.

[0119] Step 606: Perform target detection processing on the second spectrum heat map to obtain second point cloud related information obtained based on the echo corresponding to the second transmission waveform.

[0120] Step 608: Determine a second data set based on the second point cloud related information.

[0121] Step 610: Standardize the second data set to obtain a second standard data set with the step effect removed.

[0122] Optionally, determining the second standard data set may be: acquiring second waveform parameters of a second transmitting waveform; determining, for each detection point in the second data set, a radial relative velocity index change value according to a radial distance index value and the second waveform parameters corresponding to the detection point; wherein the radial relative velocity index change value is used to characterize a change in a radial relative velocity index value caused by using the second transmitting waveform; standardizing the radial relative velocity index value according to the radial relative velocity index change value to obtain a standardized radial relative velocity index value using a standard linear frequency modulation waveform; and obtaining a second standard data set where stepping effects are removed according to the standardized radial relative velocity index value and the radial distance index value.

[0123] Among them, the method for determining the radial relative velocity index value includes: determining a second relationship satisfied by the radial relative velocity index change value, the radial relative velocity index value of each detection point in the second data set, and the standard radial relative velocity index value; based on the second relationship, using the radial relative velocity index change value to standardize the radial relative velocity index value of each detection point in the second data set to obtain a standardized radial relative velocity index value using a standard linear frequency modulation waveform.

[0124] The method for determining the radial relative velocity index change value includes: determining the product of the number of signals in the second waveform parameter and the center frequency difference in the second waveform parameter; multiplying the ratio of the product to the sweep bandwidth in the second waveform parameter by the radial distance index value of each detection point in each second data set, and determining the obtained product as the radial relative velocity index change value.

[0125] It is understandable that the conversion of the second data set into the second standard data set can be achieved by the implementation principle of converting the first data set into the first standard data set, which will not be elaborated here. The detection point in the second data set can be called the second detection point, and the detection point in the first data set can be called the first detection point.

[0126] Optionally, in an exemplary embodiment, a second reflected echo corresponding to the second transmit waveform is received by a radar receiver and then passes through a mixer, a low-pass filter, an amplifier, and an analog-to-digital converter to determine a second digital signal of the second transmit waveform in the current radar processing cycle. .

[0127] A digital signal based on the second transmit waveform in the current radar processing cycle , respectively, in the fast time and slow time sampling dimensions, namely the radial distance dimension and the radial relative velocity dimension, discrete Fourier transform (or its corresponding fast algorithm in engineering implementation) is used to obtain the second spectrum heat map of the current radar processing cycle, denoted as . For this spectrum heat map The target detection algorithm is used to obtain the target radial distance index value and the target radial relative speed index value, and Q is used to represent the spectrum heat map based on the second transmission waveform. The number of target detections in the current radar processing cycle, i.e., the second quantity. Common target detection algorithms can be, but are not limited to, CA-CFAR, OS-CFAR, etc. and combined with local peak selection strategies to determine the final radial distance index value and radial relative velocity index value of the target. The target detection algorithm is not limited here. The second data set of target information contains the radial distance index value and radial relative velocity index value corresponding to each detected target, i.e.: ;

[0128] It should be noted that due to the use of step-by-step linear frequency modulation waveform, the two radial distances are close (the radial distance difference is less than ) and targets with the same radial relative speed can be distinguished in the radial relative speed dimension to ensure the resolution of the target's radial distance. However, at the same time, compared with the use of a standard linear frequency modulation waveform, the radial relative speed index value corresponding to the target will change. This change is determined by the radial distance index value of the target, the center frequency difference of two consecutive linear frequency modulation signals, and the radial distance index value of the target. , and the number of linear frequency modulation signals contained in the second transmission waveform Decision, that is, the following second relationship holds:

[0129] ;

[0130] in represents the radial relative velocity index value obtained when using the standard linear frequency modulation waveform, and the second term on the right hand side of the above equation represents the change in the radial relative velocity index value caused by using the second transmission waveform. Therefore, based on the above second relationship, the second standard data set containing target information is determined, that is:

[0131] .

[0132] In the above embodiment, the change in the radial relative velocity index value caused by using the second transmitting waveform is determined based on the radial distance index value of the target, the center frequency difference between two consecutive linear frequency modulation signals, and the number of linear frequency modulation signals contained in the second transmitting waveform. Based on this change, the determined second data set is converted to obtain a corresponding second standard data set, which can be used for extracting overall point cloud related information in subsequent signal processing.

[0133] In another exemplary embodiment, Figure 7 As shown, a target detection method is provided, which is applied to Figure 1 The application environment in FIG. 1 is taken as an example to illustrate, including the following steps 702 to 712. Among them:

[0134] Step 702: Acquire a first reflected echo of a first transmitted waveform and a second reflected echo of a second transmitted waveform.

[0135] The first transmission waveform and the second transmission waveform are stepped linear frequency modulation continuous waves transmitted in series in each radar processing cycle; the center frequency change trends of the two continuous linear frequency modulation signals corresponding to the first transmission waveform and the second transmission waveform are opposite.

[0136] Step 704: perform signal processing on the first reflected echo to obtain a first data set.

[0137] Step 706: Perform data set conversion on the first data set to obtain a first standard data set; the first standard data set includes first point cloud related information obtained based on the echo corresponding to the first transmission waveform.

[0138] Step 708: Perform signal processing on the second reflected echo to obtain a second data set.

[0139] Step 710: Perform data set conversion on the second data set to obtain a second standard data set; the second standard data set includes second point cloud related information obtained based on the echo corresponding to the second transmission waveform.

[0140] Step 712: The first standard data set and the second standard data set are processed together to obtain point cloud related information of the entire detected target.

[0141] It is understandable that the conversion processing of the data set and related data processing such as signal processing can be implemented in the above-mentioned limited manner, which will not be elaborated here.

[0142] It should be noted that although the signal processing in the above target detection method involves existing processing methods, the above target detection method solves the spectrum overlap problem caused by the use of stepped frequency modulation waveform from the root while ensuring the target radial distance resolution capability. At the same time, this method reduces target missed detection from the radar system architecture. Although the radar system framework is changed, its main core processing flow has not changed, and the change to the system architecture is small. In other words, the computational complexity is controllable, can be reused, and is easy to implement in engineering. In addition, this method can reduce the subsequent signal processing burden, for example, the signal processing burden at the point trace post-processing level.

[0143] In the above embodiment, two different step-linear frequency modulation waveforms are serially transmitted in the ramp generator of the vehicle-mounted radar chip within the frame period, and the center frequency difference of the two continuous linear frequency modulation signals corresponding to the two step-linear frequency modulation waveforms transmitted at least keeps the signs opposite, and the remaining waveform parameters can be flexibly adjusted according to system requirements. At the same time, inside the digital signal processing unit of the vehicle-mounted radar chip, the target data set is acquired for each echo, and the final data set is determined through standard data set conversion, target detection is completed, parameter estimation is performed, and point cloud is output, thereby solving the problem of target missed detection caused by the overlap of the approximate radial relative velocity target spectrum caused by the use of step-linear frequency modulation waveforms.

[0144] The following is an application scenario based on the above target detection method. For scenario 1, there are three targets in the scene, which are denoted as target 1, target 2, and target 3. The corresponding radial distances and radial relative velocities are , Target 1 and target 2 have similar radial distances and the same radial relative speeds, and target 2 and target 3 have similar radial distances and similar radial relative speeds.

[0145] In the first transmission waveform, the frequency modulation slope of each linear frequency modulation signal is , the sweep bandwidth of each linear frequency modulation signal is , each linear frequency modulation signal contains A fast time sampling, that is Each signal transmission cycle contains A linear frequency modulation signal, The center frequency is The center frequency difference between two consecutive linear frequency modulation signals is It is worth noting that based on the waveform parameters of the first transmission waveform, Without the use of a stepped linear frequency modulation waveform, target 1 and target 2 cannot be distinguished. The target reflected echo is received by the radar receiver and then passes through a mixer, a low-pass filter, an amplifier, and an analog-to-digital converter to determine the digital signal of the first transmitted waveform in the current radar processing cycle. .

[0146] Based on the digital signal of the first transmission waveform in the current radar processing cycle , respectively in the fast time and slow time sampling dimensions, namely the radial distance dimension and the radial relative velocity dimension, and the fast Fourier transform is used to implement the discrete Fourier transform to obtain the first spectrum heat map of the current radar processing cycle, denoted as ,like Figure 8 The horizontal axis is the radial distance index value, and the vertical axis is the radial relative velocity index value. OS-CFAR is used in combination with the local peak selection strategy to determine the final radial distance index value and radial relative velocity index value of the target. The first spectrum heat map based on the first transmission waveform The number of target detections in the current radar processing cycle is P = 2. Accordingly, the first data set of target information is as follows: .

[0147] Based on the radial distance index value corresponding to each detection point in the first data set, the center frequency difference between two continuous linear frequency modulation signals , and the number N1 of linear frequency modulation signals contained in the first transmission waveform determines the first standard data set:

[0148] .

[0149] The above phenomenon shows that due to the use of the stepped linear frequency modulation waveform, target 1 and target 2 can be distinguished. However, since only a single stepped linear frequency modulation waveform is used, the spectrum of target 3 and target 1, which can be distinguished in the radial relative velocity dimension, overlaps and cannot be identified as two targets. Figure 8 As shown, the final number of target detections is two.

[0150] In the second transmission waveform, the frequency modulation slope of each linear frequency modulation signal is , the sweep bandwidth of each linear frequency modulation signal is B2=B1=100MHz, and each linear frequency modulation signal contains M2=M1=128 fast time samples, that is, m=0, ..., 127. Each signal transmission cycle contains N2=N1=256 linear frequency modulation signals, that is, n=0, ..., 255. The center frequency is The center frequency difference between two consecutive linear frequency modulation signals is It is worth noting that based on the waveform parameters of the second transmission waveform, If the stepped linear frequency modulation waveform is not used, target 1 and target 2 are still indistinguishable. The second reflected echo is received by the radar receiver and then passes through a mixer, a low-pass filter, an amplifier, and an analog-to-digital converter to determine the second digital signal of the first transmitted waveform in the current radar processing cycle. .

[0151] A second digital signal based on the second transmit waveform in the current radar processing cycle , respectively in the fast time and slow time sampling dimensions, namely the radial distance dimension and the radial relative velocity dimension, and the fast Fourier transform is used to implement the discrete Fourier transform to obtain the second spectrum heat map of the current radar processing cycle, denoted as ,like Fig. 9 The horizontal axis is the radial distance index value, and the vertical axis is the radial relative velocity index value. OS-CFAR is used in combination with the local peak selection strategy to determine the final radial distance index value and radial relative velocity index value of the target. The spectrum heat map based on the second transmission waveform The number of target detections in the current radar processing cycle is Q = 3. Accordingly, the second data set of target information is as follows:

[0152] ;

[0153] Based on the radial distance index value corresponding to each detection point in the second data set, the center frequency difference of two continuous linear frequency modulation signals , and the number N2 of linear frequency modulation signals contained in the second transmission waveform determines the second standard data set:

[0154] ;

[0155] The final target standard dataset is the union of the first standard dataset and the second standard dataset, as shown below:

[0156] ;

[0157] Among them, [(23,82)] represents the point information corresponding to target 1, [(24,85)] and [(24,86)] represent the point information of target 2, and [(24,79)] and [(24,80)] represent the point information of target 3. Calculate the radial distance and radial relative velocity, and execute the subsequent radar signal processing process.

[0158] From this example, we can see that the above target detection method can ensure the target radial distance resolution capability, that is, target 1 and target 2 can be distinguished as two targets, and at the same time, it also avoids the risk of missing target 3. Ultimately, it ensures that all three targets can be correctly detected.

[0159] For scenario 2: There are 4 targets in the scenario, denoted as target 1, target 2, target 3, and target 4. The corresponding radial distances and radial relative velocities are , , , Target 1 and target 2 have similar radial distances and similar radial relative speeds, target 2 and target 3 have similar radial distances and similar radial relative speeds, and target 2 and target 4 have similar radial distances and similar radial relative speeds. In the first transmission waveform, the frequency modulation slope of each linear frequency modulation signal is , the sweep bandwidth of each linear frequency modulation signal is B1=100MHZ, and each linear frequency modulation signal contains M1=128 fast time samples, that is, Each signal transmission cycle contains A linear frequency modulation signal, The center frequency is The center frequency difference between two consecutive linear frequency modulation signals is It is worth noting that based on the waveform parameters of the first transmission waveform, Without the use of a stepped linear frequency modulation waveform, target 1 and target 2 cannot be distinguished. The target reflected echo is received by the radar receiver and then passes through a mixer, a low-pass filter, an amplifier, and an analog-to-digital converter to determine the first digital signal of the first transmitted waveform in the current radar processing cycle. .

[0160] Based on the first digital signal of the first transmit waveform in the current radar processing cycle , respectively in the fast time and slow time sampling dimensions, namely the radial distance dimension and the radial relative velocity dimension, and the fast Fourier transform is used to implement the discrete Fourier transform to obtain the first spectrum heat map of the current radar processing cycle, denoted as ,like Fig.10 OS-CFAR is used in combination with the local peak selection strategy to determine the final radial distance index value and radial relative velocity index value of the target, based on the first spectrum heat map of the first transmission waveform. The number of target detections in the current radar processing cycle is P = 3. Accordingly, the first data set of target information is as follows:

[0161] .

[0162] Based on the radial distance index value corresponding to each detection point of the first data set, the center frequency difference between two continuous linear frequency modulation signals , and the number N1 of linear frequency modulation signals contained in the first transmission waveform determines the first standard data set:

[0163] .

[0164] The above phenomenon shows that due to the use of the stepped linear frequency modulation waveform, target 1 can be distinguished from target 2, and target 4 can be distinguished from target 1 and target 2. However, since only a single stepped linear frequency modulation waveform is used, the spectrum of target 3 and target 1, which can be distinguished in the radial relative velocity dimension, will overlap and cannot be identified as two targets. Figure 8 As shown, the final number of target detections is three.

[0165] In the second transmission waveform, the frequency modulation slope of each linear frequency modulation signal is , the sweep bandwidth of each linear frequency modulation signal is , each linear frequency modulation signal contains A fast time sampling, that is Each signal transmission cycle contains A linear frequency modulation signal, The center frequency is The center frequency difference between two consecutive linear frequency modulation signals is It is worth noting that based on the waveform parameters of the second transmission waveform, If the stepped linear frequency modulation waveform is not used, target 1 and target 2 are still indistinguishable. The target reflection echo is received by the radar receiver and then passes through the mixer, low-pass filter, amplifier and analog-to-digital converter to determine the digital signal of the first transmission waveform in the current radar processing cycle. Based on the digital signal of the second transmission waveform in the current radar processing cycle , respectively in the fast time and slow time sampling dimensions, namely the radial distance dimension and the radial relative velocity dimension, and the fast Fourier transform is used to implement the discrete Fourier transform to obtain the second spectrum heat map of the current radar processing cycle, denoted as ,like Fig.11 Correspondingly, the spectrum echo energy changes with the radial relative velocity index value as shown in Fig.12 OS-CFAR is used in combination with the local peak selection strategy to determine the final radial distance index value and radial relative velocity index value of the target, based on the spectrum heat map of the second transmission waveform. The number of target detections in the current radar processing cycle is Q = 4. Accordingly, the second data set of target information is as follows:

[0166] ;

[0167] Based on the radial distance index value corresponding to each detection point of the second data set, the center frequency difference of two consecutive linear frequency modulation signals , and the number N2 of linear frequency modulation signals contained in the second transmission waveform determines the second standard data set:

[0168] ;

[0169] The final target standard data set is the union of the first standard data set and the second standard data set:

[0170] ;

[0171] Among them, [(23, 82)] represents the point information corresponding to target 1, [(24, 85)] and [(24, 86)] represent the point information of target 2, [(24, 79)] and [(24, 80)] represent the point information of target 3, and [(24, 91)] and [(24, 92)] represent the point information of target 4. Based on this point information, the radial distance and radial relative velocity are solved, and the subsequent radar signal processing process is executed.

[0172] From the example of scenario 2, we can see that the above target detection method can ensure the target radial distance resolution capability, that is, target 1 and target 2 can be distinguished as two targets, and at the same time, it also avoids the risk of missing targets 3 and 4. Finally, it ensures that all four targets can be detected correctly.

[0173] It should be understood that, although the various steps in the flowcharts involved in the above-mentioned embodiments are displayed in sequence according to the indication of the arrows, these steps are not necessarily executed in sequence according to the order indicated by the arrows. Unless there is a clear explanation in this article, the execution of these steps does not have a strict order restriction, and these steps can be executed in other orders. Moreover, at least a part of the steps in the flowcharts involved in the above-mentioned embodiments can include multiple steps or multiple stages, and these steps or stages are not necessarily executed at the same time, but can be executed at different times, and the execution order of these steps or stages is not necessarily to be carried out in sequence, but can be executed in turn or alternately with other steps or at least a part of the steps or stages in other steps.

[0174] Based on the same inventive concept, the embodiment of the present application also provides a radar system for implementing the target detection method involved above. The implementation scheme for solving the problem provided by the system is similar to the implementation scheme recorded in the above method, so the specific limitations in one or more radar system embodiments provided below can refer to the limitations on the target detection method above, and will not be repeated here.

[0175] In an exemplary embodiment, Fig.13 As shown, a radar system is provided, the radar system includes a transmitting antenna, a receiving antenna and a signal processing module, wherein:

[0176] The transmitting antenna is used to transmit the first transmitting waveform and the second transmitting waveform in series during the radar processing cycle, the first transmitting waveform and the second transmitting waveform are both stepped linear frequency modulation continuous waves; the center frequency change trends of the two continuous linear frequency modulation signals corresponding to the first transmitting waveform and the second transmitting waveform are opposite;

[0177] A receiving antenna, used to receive a first reflected echo of a first transmitted waveform and a second reflected echo of a second transmitted waveform;

[0178] The signal processing module is used to perform signal processing on the first reflected echo to obtain a first standard data set with stepping effects removed; the first standard data set includes first point cloud related information obtained based on the echo corresponding to the first transmitting waveform; the second reflected echo is signal processed to obtain a second standard data set with stepping effects removed; the second standard data set includes second point cloud related information obtained based on the echo corresponding to the second transmitting waveform; the first standard data set and the second standard data set are combined and processed to obtain point cloud related information of the overall detected target.

[0179] In the above radar system, two different stepped linear frequency modulation waveforms are serially transmitted in the frame period in the ramp generator of the vehicle-mounted radar chip, and the center frequency difference of the two continuous linear frequency modulation signals corresponding to the two stepped linear frequency modulation waveforms transmitted at least keeps the signs opposite, and the remaining waveform parameters can be flexibly adjusted according to system requirements. At the same time, inside the digital signal processing unit of the vehicle-mounted radar chip, the target data set is acquired for each echo, and the final data set is determined through standard data set conversion, target detection is completed, parameter estimation is performed, and point cloud is output, which solves the problem of target missed detection caused by the overlap of the approximate radial relative velocity target spectrum caused by the use of stepped linear frequency modulation waveforms.

[0180] Optionally, in an exemplary embodiment, the signal processing module is further used to perform signal processing on the first reflected echo to obtain a first digital signal of the first transmission waveform in the current radar processing cycle;

[0181] After sampling and coherent accumulation of the first digital signal in the fast time sampling dimension and the slow time sampling dimension and incoherent accumulation between receiving channels, a first spectrum heat map of the current radar processing cycle is obtained;

[0182] Performing target detection processing on the first spectrum heat map to obtain a first data set;

[0183] The first data set is standardized to obtain a first standard data set with the step effect removed.

[0184] Optionally, in an exemplary embodiment, the signal processing module is further used to obtain a first waveform parameter of the first transmission waveform;

[0185] For each detection point in the first data set, a radial relative velocity index change value is determined according to the radial distance index value of each detection point and the first waveform parameter; wherein the radial relative velocity index change value is used to characterize the change of the radial relative velocity index value caused by using the first transmission waveform;

[0186] The radial relative velocity index value is standardized according to the radial relative velocity index change value to obtain a standardized radial relative velocity index value using a standard linear frequency modulation waveform;

[0187] According to the standardized radial relative velocity index value and the radial distance index value, a first standard data set is obtained to remove the stepping effect.

[0188] Optionally, in an exemplary embodiment, the signal processing module is further used to determine a first relationship satisfied among the radial relative velocity index change value, the radial relative velocity index value of each detection point, and the standard radial relative velocity index value;

[0189] Based on the first relationship, the radial relative velocity index value of each detection point is standardized using the radial relative velocity index change value to obtain a standardized radial relative velocity index value using a standard linear frequency modulation waveform.

[0190] Optionally, in an exemplary embodiment, the first waveform parameter includes a center frequency difference between two consecutive linear frequency modulation signals in the first transmit waveform, a signal quantity of the linear frequency modulation signal included in the first transmit waveform, and a frequency sweep bandwidth of the linear frequency modulation signal, and the signal processing module is further used to determine a product of the signal quantity and the center frequency difference;

[0191] The ratio of the product to the frequency sweep bandwidth is multiplied by the radial distance index value of each detection point, and the obtained product is determined as the radial relative velocity index change value.

[0192] Optionally, in an exemplary embodiment, the signal processing module is also used to normalize the radial relative velocity index value based on the first relationship by determining the difference between the radial relative velocity index value and the radial relative velocity index change value of each detection point to obtain a standardized radial relative velocity index value using a standard linear frequency modulation waveform.

[0193] Optionally, in an exemplary embodiment, the signal processing module is further used to perform signal processing on the second reflected echo to obtain a second digital signal of the second transmission waveform in the current radar processing cycle;

[0194] After sampling and coherent accumulation of the second digital signal in the fast time sampling dimension and the slow time sampling dimension and incoherent accumulation between receiving channels, a second spectrum heat map of the current radar processing cycle is obtained;

[0195] Performing target detection processing on the second spectrum heat map to obtain a second data set;

[0196] The second data set is standardized to obtain a second standard data set with the step effect removed.

[0197] Each module in the above radar system can be implemented in whole or in part by software, hardware or a combination thereof. Each module can be embedded in or independent of a processor in a computer device in the form of hardware, or can be stored in a memory in a computer device in the form of software, so that the processor can call and execute operations corresponding to each module.

[0198] In an exemplary embodiment, a chip is provided, and its internal structure diagram can be as follows: Fig.14 As shown. The computer device includes a processor and a memory, the processor may be a central processing unit, a specific ASIC, or one or more integrated circuits for controlling program execution, and the memory includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. When the computer program is executed by the processor, a target detection method is implemented.

[0199] Those skilled in the art will understand that Fig.14 The structure shown in the figure is only a block diagram of a part of the structure related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. The specific computer device may include more or fewer components than those shown in the figure, or combine certain components, or have a different arrangement of components.

[0200] In an exemplary embodiment, a computer device is further provided, including a memory and a processor, wherein a computer program is stored in the memory, and the processor implements the steps in the above-mentioned method embodiments when executing the computer program.

[0201] In one embodiment, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the steps in the above-mentioned method embodiments are implemented.

[0202] In one embodiment, a computer program product is provided, including a computer program, which implements the steps in the above method embodiments when executed by a processor.

[0203] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, stored data, displayed data, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of relevant data must comply with relevant regulations.

[0204] A person of ordinary skill in the art can understand that all or part of the processes in the above-mentioned embodiment method can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to the memory, database or other medium used in the embodiments provided in the present application can include at least one of non-volatile memory and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. As an illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM). The database involved in each embodiment provided in this application may include at least one of a relational database and a non-relational database. Non-relational databases may include distributed databases based on blockchains, etc., but are not limited to this. The processor involved in each embodiment provided in this application may be a general-purpose processor, a central processing unit, a graphics processor, a digital signal processor, a programmable logic unit, a data processing logic unit based on quantum computing, an artificial intelligence (AI) processor, etc., but are not limited to this.

[0205] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this application.

[0206] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. A target detection method, characterized in that: The method comprises: Acquire a first reflected echo of a first transmitting waveform and a second reflected echo of a second transmitting waveform; wherein the first transmitting waveform and the second transmitting waveform are stepped linear frequency modulation continuous waves transmitted in series in each radar processing cycle; and the center frequency change trends of two continuous linear frequency modulation signals corresponding to the first transmitting waveform and the second transmitting waveform are opposite; Performing signal processing on the first reflected echo to obtain a first standard data set without stepping effects; the first standard data set includes first point cloud related information obtained based on the echo corresponding to the first transmitting waveform; Performing signal processing on the second reflected echo to obtain a second standard data set without stepping effect; the second standard data set includes second point cloud related information based on the echo corresponding to the second transmission waveform; The first standard data set and the second standard data set are processed together to obtain point cloud information of the entire detected target; The performing signal processing on the first reflected echo to obtain a first standard data set with the step effect removed includes: Performing signal processing on the first reflected echo to obtain a first digital signal of the first transmitting waveform in a current radar processing cycle; After sampling and coherent accumulation of the first digital signal in a fast time sampling dimension and a slow time sampling dimension, and incoherent accumulation between receiving channels, a first spectrum heat map of a current radar processing cycle is obtained; Performing target detection processing on the first spectrum heat map to obtain a first data set; Performing standardization processing on the first data set to obtain a first standard data set without stepping effects; The performing signal processing on the second reflected echo to obtain a second standard data set without the stepping effect includes: Performing signal processing on the second reflected echo to obtain a second digital signal of the second transmitting waveform in a current radar processing cycle; After sampling and coherent accumulation of the second digital signal in a fast time sampling dimension and a slow time sampling dimension, and incoherent accumulation between receiving channels, a second spectrum heat map of the current radar processing cycle is obtained; Performing target detection processing on the second spectrum heat map to obtain a second data set; The second data set is standardized to obtain a second standard data set with the step effect removed.

2. The method according to claim 1, characterized in that The first point cloud related information includes a radial distance index value and a radial relative speed index value, and the first data set is subjected to standardization processing to obtain a first standard data set without stepping effects, including: Acquire a first waveform parameter of the first transmit waveform; For each detection point in the first data set, determine a radial relative velocity index change value according to the radial distance index value of the detection point and the first waveform parameter; wherein the radial relative velocity index change value is used to characterize the change of the radial relative velocity index value caused by using the first transmitting waveform; Standardizing the radial relative velocity index value according to the radial relative velocity index change value to obtain a standardized radial relative velocity index value using a standard linear frequency modulation waveform; A first standard data set with stepping effect removed is obtained according to the standardized radial relative velocity index value and the radial distance index value.

3. The method according to claim 2, characterized in that The step of normalizing the radial relative velocity index value according to the radial relative velocity index change value to obtain a normalized radial relative velocity index value using a standard linear frequency modulation waveform includes: Determine a first relationship satisfied among the radial relative velocity index change value, the radial relative velocity index value of the detection point, and a standard radial relative velocity index value; Based on the first relationship, the radial relative velocity index value of each detection point in the first data set is standardized using the radial relative velocity index change value to obtain a standardized radial relative velocity index value using a standard linear frequency modulation waveform.

4. The method according to claim 2, characterized in that: The first waveform parameters include a center frequency difference between two consecutive linear frequency modulation signals in the first transmission waveform, the number of linear frequency modulation signals contained in the first transmission waveform, and a frequency sweep bandwidth of the linear frequency modulation signal. The step of determining, for each detection point in the first data set, a radial relative velocity index change value according to the radial distance index value of the detection point and the first waveform parameter, comprises: Determining the product of the number of signals and the center frequency difference; The ratio of the product to the frequency sweep bandwidth is multiplied by the radial distance index value of each of the detection points, and the obtained product is determined as the radial relative velocity index change value.

5. The method according to claim 3, characterized in that: The step of normalizing the radial relative velocity index value of each detection point by using the radial relative velocity index change value based on the first relationship to obtain a normalized radial relative velocity index value under a standard linear frequency modulation waveform includes: Based on the first relationship, the radial relative velocity index value is standardized by determining the difference between the radial relative velocity index value and the radial relative velocity index change value of each detection point to obtain a standardized radial relative velocity index value using a standard linear frequency modulation waveform.

6. A radar system, characterized in that: The radar system includes a transmitting antenna, a receiving antenna and a signal processing module, wherein: The transmitting antenna is used to transmit a first transmitting waveform and a second transmitting waveform in series during a radar processing cycle, wherein the first transmitting waveform and the second transmitting waveform are both stepped linear frequency modulation continuous waves; and the center frequency change trends of two continuous linear frequency modulation signals corresponding to the first transmitting waveform and the second transmitting waveform are opposite; The receiving antenna is used to receive a first reflected echo of a first transmitted waveform and a second reflected echo of a second transmitted waveform; The signal processing module is used to perform signal processing on the first reflected echo to obtain a first standard data set without stepping effects; the first standard data set includes first point cloud related information obtained based on the echo corresponding to the first transmitting waveform; Performing signal processing on the second reflected echo to obtain a second standard data set without stepping effect; the second standard data set includes second point cloud related information based on the echo corresponding to the second transmission waveform; The first standard data set and the second standard data set are processed together to obtain point cloud information of the entire detected target; The signal processing module is further used to perform signal processing on the first reflected echo to obtain a first digital signal of the first transmitting waveform in a current radar processing cycle; After sampling and coherent accumulation of the first digital signal in a fast time sampling dimension and a slow time sampling dimension, and incoherent accumulation between receiving channels, a first spectrum heat map of a current radar processing cycle is obtained; Performing target detection processing on the first spectrum heat map to obtain a first data set; Performing standardization processing on the first data set to obtain a first standard data set without stepping effects; Performing signal processing on the second reflected echo to obtain a second digital signal of the second transmitting waveform in a current radar processing cycle; After sampling and coherent accumulation of the second digital signal in a fast time sampling dimension and a slow time sampling dimension, and incoherent accumulation between receiving channels, a second spectrum heat map of the current radar processing cycle is obtained; Performing target detection processing on the second spectrum heat map to obtain a second data set; The second data set is standardized to obtain a second standard data set with the step effect removed.

7. The system according to claim 6, characterized in that The first point cloud related information includes a radial distance index value and a radial relative speed index value, and the signal processing module is further used to obtain a first waveform parameter of the first transmitting waveform; For each detection point in the first data set, determine a radial relative velocity index change value according to the radial distance index value of the detection point and the first waveform parameter; wherein the radial relative velocity index change value is used to characterize the change of the radial relative velocity index value caused by using the first transmitting waveform; Standardizing the radial relative velocity index value according to the radial relative velocity index change value to obtain a standardized radial relative velocity index value using a standard linear frequency modulation waveform; A first standard data set with stepping effect removed is obtained according to the standardized radial relative velocity index value and the radial distance index value.

8. The system according to claim 7, characterized in that The signal processing module is further used to determine a first relationship satisfied among the radial relative velocity index change value, the radial relative velocity index value of the detection point, and the standard radial relative velocity index value; Based on the first relationship, the radial relative velocity index value of each detection point in the first data set is standardized using the radial relative velocity index change value to obtain a standardized radial relative velocity index value using a standard linear frequency modulation waveform.

9. A chip comprising a memory and a processor, wherein the memory stores a computer program, characterized in that: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 5 are implemented.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 5 are implemented.

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