Method for reducing radar blind area, radar system and storage medium

Abstract

The application relates to a radar blind area reduction method, a radar system and a storage medium, wherein the radar blind area reduction method comprises the following steps: controlling a radar to alternately work between a first working frequency point and a second working frequency point; the first working frequency point is used for forming a first detection beam, and the second working frequency point is used for forming a second detection beam; wherein the beam width of the second detection beam is wider than the beam width of the first detection beam, and the detection range of the second detection beam at least partially covers the near-field blind area of the first detection beam; and the detection data obtained by the first detection beam and the second detection beam is fused to generate a target detection result after the blind area of the radar is reduced. Through the application, the problem of high radar arrangement cost is solved.

Description

Technical Field

[0001] This application relates to the field of radar technology, and in particular to radar blind zone reduction methods, radar systems, and storage media. Background Technology

[0002] Millimeter-wave radar is widely used in security monitoring, intelligent transportation, and perimeter protection due to its advantages such as high resolution, strong anti-jamming capabilities, and small size. In these applications, to obtain a wide detection field of view, radars are usually installed high on poles or buildings. However, this high-mounting method, combined with the inherent technical characteristics of millimeter-wave radar, generally suffers from detection blind spots.

[0003] In related technologies, millimeter-wave radar deployment typically employs a full-coverage strategy, which involves increasing the number of radars to eliminate detection blind spots as much as possible, ensuring complete monitoring of the target scene. Alternatively, it relies on the collaboration of more sensors or system-level coverage optimization, such as placing a camera below the radar for fixed-point detection. However, both of these methods require additional hardware, resulting in high radar deployment costs.

[0004] Currently, no effective solution has been proposed to address the high cost of radar deployment in related technologies. Summary of the Invention

[0005] This application provides a method for reducing radar blind spots, a radar system, and a storage medium to at least address the problem of high radar deployment costs in related technologies.

[0006] In a first aspect, embodiments of this application provide a method for reducing radar blind spots, the method comprising:

[0007] The control radar operates alternately between a first operating frequency and a second operating frequency; the first operating frequency is used to form a first detection beam, and the second operating frequency is used to form a second detection beam.

[0008] Wherein, the beamwidth of the second detection beam is wider than the beamwidth of the first detection beam, and the detection range of the second detection beam at least partially covers the near-field blind zone of the first detection beam;

[0009] The detection data obtained from the first detection beam and the second detection beam are fused together to generate the target detection result after the blind zone of the radar is reduced.

[0010] In some embodiments, before the control radar alternates between a first operating frequency and a second operating frequency, the method further includes:

[0011] Based on the test radiation pattern of the radar within its operating bandwidth, the first operating frequency and the second operating frequency are determined; the first operating frequency is the frequency at which the antenna impedance of the radar is optimally matched, and the second operating frequency is the frequency at which the elevation beamwidth of the second detection beam reaches its maximum within the operating bandwidth.

[0012] In some embodiments, determining the first operating frequency and the second operating frequency based on a test pattern of the radar within its operating bandwidth includes:

[0013] Within the operating bandwidth, test patterns corresponding to multiple frequency points are measured, and the main beamwidth of each frequency point is calculated based on the test patterns;

[0014] Calculate the first beamwidth with the narrowest beamwidth and the second beamwidth with the widest beamwidth from each of the main beamwidths.

[0015] The frequency point corresponding to the first beamwidth is determined as the first operating frequency point;

[0016] The frequency point corresponding to the second beamwidth is determined as the second operating frequency point.

[0017] In some embodiments, the method further includes:

[0018] Based on the test pattern, at least one third beamwidth is determined where the main beamwidth is between the first beamwidth and the second beamwidth;

[0019] Based on the third beamwidth, at least one corresponding third operating frequency point is determined;

[0020] The radar operates alternately between the first operating frequency, the second operating frequency, and the third operating frequency.

[0021] In some embodiments, the control radar operates alternately between a first operating frequency and a second operating frequency, including:

[0022] Obtain the first pulse count and the second pulse count; the first pulse count is greater than the second pulse count.

[0023] Based on the first pulse count and the first operating frequency, a first subframe is constructed; and,

[0024] Based on the second pulse number and the second operating frequency, a second subframe is constructed;

[0025] Based on the first subframe and the second subframe, an interleaved frame waveform is constructed; the radar operates alternately between the first operating frequency and the second operating frequency by transmitting the interleaved frame waveform.

[0026] In some embodiments, calculating the detection range of the second detection beam includes:

[0027] The near-field blind zone boundary of the first detection beam is calculated based on the installation height and downtilt angle of the radar.

[0028] Based on the near-field blind zone boundary, the horizontal detection maximum distance of the second detection beam is calculated, and the detection range of the second detection beam is determined according to the horizontal detection maximum distance; wherein, the horizontal detection maximum distance is the maximum distance of the intersection point formed by the second detection beam on the ground.

[0029] In some embodiments, the maximum horizontal detection distance of the second detection beam is equal to the near-field blind zone boundary of the first detection beam.

[0030] In some embodiments, the process of fusing the detection data obtained from the first detection beam and the second detection beam, and generating the target detection result with reduced blind zone of the radar, includes:

[0031] For the echo signal received at the second operating frequency, a matched filtering algorithm is used for target distance detection;

[0032] The target point cloud data obtained based on the matched filtering algorithm is merged with the target point cloud data obtained by fast Fourier transform at the first operating frequency to obtain the target detection result.

[0033] Secondly, embodiments of this application provide a radar system, including:

[0034] A beam control unit is used to control the radar to operate alternately between a first operating frequency and a second operating frequency; the first operating frequency is used to form a first detection beam, and the second operating frequency is used to form a second detection beam.

[0035] Wherein, the beamwidth of the second detection beam is wider than the beamwidth of the first detection beam, and the detection range of the second detection beam at least partially covers the near-field blind zone of the first detection beam;

[0036] The data processing unit is used to fuse the detection data obtained from the first detection beam and the second detection beam respectively, and generate the target detection result after the blind zone of the radar is reduced.

[0037] Thirdly, embodiments of this application provide a storage medium storing a computer program that, when executed by a processor, implements the radar blind zone reduction method as described in the first aspect above.

[0038] Compared to related technologies, the radar blind zone reduction method, radar system, and storage medium provided in this application embodiment control the radar to operate alternately between a first operating frequency and a second operating frequency; the first operating frequency is used to form a first detection beam, and the second operating frequency is used to form a second detection beam; wherein, the beamwidth of the second detection beam is wider than the beamwidth of the first detection beam, and the detection range of the second detection beam at least partially covers the near-field blind zone of the first detection beam; the detection data obtained from the first detection beam and the second detection beam are fused to generate the target detection result after the radar blind zone reduction.

[0039] By controlling the radar to alternately emit a narrow and concentrated first detection beam and a wide and divergent second detection beam, the coverage area of ​​the second detection beam can be extended forward, at least partially covering the near-field blind zone that the first detection beam cannot reach due to geometric obstruction and beam pointing. This effectively expands the detection space, enhances the radar's ability to detect near-ground and ground-level targets in critical scenarios such as security and transportation, while maintaining the radar's original long-range detection performance. This achieves a low-cost, high-efficiency system performance optimization, ultimately solving the inherent near-field blind zone detection problem of high-altitude millimeter-wave radar deployment without increasing hardware costs or complexity, thus effectively addressing the issue of high radar deployment costs.

[0040] Details of one or more embodiments of this application are set forth in the following drawings and description to make other features, objects and advantages of this application more readily apparent. Attached Figure Description

[0041] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0042] Figure 1 This is a hardware structure block diagram of a terminal for a radar blind zone reduction method according to an embodiment of this application;

[0043] Figure 2 This is a schematic diagram of a radar detection blind zone based on relevant technologies;

[0044] Figure 3 This is a flowchart of a radar blind zone reduction method according to an embodiment of this application;

[0045] Figure 4 This is a schematic diagram of the waveform design of an interleaved frame according to an embodiment of this application;

[0046] Figure 5 This is a schematic diagram of a radar-mounted detection system according to an embodiment of this application;

[0047] Figure 6A This is a schematic diagram illustrating the detection range of a mismatched beam and a normal beam according to an embodiment of this application;

[0048] Figure 6B This is a schematic diagram illustrating the detection range of a mismatched beam and a normal beam according to an embodiment of this application;

[0049] Figure 6C This is a schematic diagram illustrating the detection range of a mismatched beam and a normal beam according to an embodiment of this application;

[0050] Figure 7 This is a schematic diagram of frame fusion at different frequency points according to an embodiment of this application;

[0051] Figure 8A This is a schematic diagram of the detection results before optimization according to an embodiment of this application;

[0052] Figure 8B This is a schematic diagram of an optimized detection result according to an embodiment of this application;

[0053] Figure 9 This is a flowchart of another radar blind zone reduction method according to an embodiment of this application;

[0054] Figure 10 This is an antenna pattern at different frequencies according to an embodiment of this application;

[0055] Figure 11 This is a pitch pattern at a different frequency point according to an embodiment of this application;

[0056] Figure 12 This is a schematic diagram of a detection area at different frequencies according to an embodiment of this application;

[0057] Figure 13 This is a structural block diagram of a radar system according to an embodiment of this application. Detailed Implementation

[0058] To make the objectives, technical solutions, and advantages of this application clearer, the application is described and illustrated below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the application. All other embodiments obtained by those skilled in the art based on the embodiments provided in this application without inventive effort are within the scope of protection of this application. Furthermore, it is understood that although the efforts made in such a development process may be complex and lengthy, for those skilled in the art related to the content disclosed in this application, modifications to design, manufacturing, or production based on the technical content disclosed in this application are merely conventional technical means and should not be construed as insufficient disclosure of the content of this application.

[0059] In this application, the reference to "embodiment" means that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment that is mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described in this application may be combined with other embodiments without conflict.

[0060] Unless otherwise defined, the technical or scientific terms used in this application shall have the ordinary meaning understood by one of ordinary skill in the art to which this application pertains. The terms “a,” “an,” “an,” “the,” and similar words used in this application do not indicate quantity limitation and may indicate singular or plural. The terms “comprising,” “including,” “having,” and any variations thereof used in this application are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or device that includes a series of steps or modules (units) is not limited to the listed steps or units, but may also include steps or units not listed, or may include other steps or units inherent to these processes, methods, products, or devices. The terms “connected,” “linked,” “coupled,” and similar words used in this application are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. “Multiple” used in this application means two or more. “And / or” describes the relationship between related objects, indicating that three relationships may exist; for example, “A and / or B” can represent: A alone, A and B simultaneously, and B alone. The terms “first,” “second,” “third,” etc., used in this application are merely to distinguish similar objects and do not represent a specific ordering of the objects.

[0061] The method embodiments provided in this example can be executed on a terminal, computer, or similar computing device. Taking running on a terminal as an example, Figure 1 This is a hardware structure block diagram of a terminal for a radar blind zone reduction method according to an embodiment of this application. Figure 1 As shown, a terminal may include one or more ( Figure 1 Only one is shown in the diagram. A processor 102 (which may include, but is not limited to, a microprocessor MCU or a programmable logic device FPGA, etc.) and a memory 104 for storing data are also shown. Optionally, the terminal may further include a transmission device 106 for communication functions and an input / output device 108. Those skilled in the art will understand that... Figure 1 The structure shown is for illustrative purposes only and does not limit the structure of the terminal described above. For example, the terminal may also include components that are larger than... Figure 1 The more or fewer components shown, or having the same Figure 1 The different configurations shown.

[0062] The memory 104 can be used to store computer programs, such as application software programs and modules, like the computer program corresponding to the radar blind zone reduction method in this embodiment. The processor 102 executes various functional applications and data processing by running the computer program stored in the memory 104, thereby implementing the above-described method. The memory 104 may include high-speed random access memory and may also include non-volatile memory, such as one or more magnetic storage devices, flash memory, or other non-volatile solid-state memory. In some instances, the memory 104 may further include memory remotely located relative to the processor 102, and these remote memories can be connected to the terminal via a network. Examples of such networks include, but are not limited to, the Internet, corporate intranets, local area networks, mobile communication networks, and combinations thereof.

[0063] The transmission device 106 is used to receive or send data via a network. Specific examples of the network described above may include a wireless network provided by the terminal's communication provider. In one example, the transmission device 106 includes a Network Interface Controller (NIC), which can connect to other network devices via a base station to communicate with the Internet. In another example, the transmission device 106 may be a Radio Frequency (RF) module used for wireless communication with the Internet.

[0064] As described in the background section, millimeter-wave radars generally suffer from a near-end blind zone due to their high-frequency physical characteristics and system design constraints. Specifically, this blind zone problem is essentially caused by the coupling of several factors: First, the short wavelength characteristics of the millimeter-wave band result in weak electromagnetic wave diffraction capabilities, adhering to strict line-of-sight propagation and unable to effectively bypass near-ground obstructions; Second, to optimize long-range target detection, the radar main lobe is usually set with a positive elevation angle (slightly tilted downwards), which, combined with a limited elevation beamwidth (typically 5°~20°), results in a low-elevation angle space that is not effectively covered between the vertical projection area and the ground starting illumination point of the main beam; Third, high-position installation (often higher than 2.5 meters) further exacerbates the geometric obstruction effect.

[0065] This results in two typical blind zones: 1. Vertical projection blind zone ("the area directly below the radar installation point"), where the main lobe energy can barely reach the radar; 2. Near-ground coverage blind zone, where the intersection of the beam axis and the ground lags behind the radar position in horizontal distance, forming a narrow, undetected near-ground band (typically extending 5-20 meters) before the main lobe illumination starting point. These blind zones pose a risk of missed detection for ground-level targets, objects near the installation structure, and extremely close-range moving objects, becoming an inherent limitation of millimeter-wave radar in high-altitude deployment scenarios such as security and transportation. Please refer to [link / reference]. Figure 2 The image illustrates the core detection characteristics of a millimeter-wave radar deployed at a high altitude: a blind zone starting directly below the radar and extending forward, and an effective detection area emanating from the radar and covering the ground area in front. The blind zone is a geometric dead angle formed by the radar beam's downward tilt, preventing it from reaching the ground directly below the radar. Its apex is the vertical projection area where the radar beam is "blacked out," while the main body is the narrow strip of ground between the initial beam illumination point and the radar that is not covered.

[0066] In related technologies, to address the aforementioned blind spot problem, a common approach is to deploy radars with full coverage, which involves increasing the number of radars to eliminate blind spots as much as possible, ensuring complete monitoring of vehicle trajectories. Alternatively, more sensors can be used in conjunction with radars, or system-level coverage optimization can be employed, such as placing a camera below the radar for point-to-point detection. However, both methods require additional hardware, resulting in high radar deployment costs. Therefore, how to reduce radar blind spots without using excessive sensors is a pressing issue that needs to be addressed.

[0067] Based on this, this embodiment provides a method for reducing radar blind spots. Figure 3 This is a flowchart of a radar blind zone reduction method according to an embodiment of this application, such as... Figure 3 As shown, the process includes the following steps:

[0068] Step S310: Control the radar to operate alternately between a first operating frequency and a second operating frequency; the first operating frequency is used to form a first detection beam, and the second operating frequency is used to form a second detection beam; wherein, the beamwidth of the second detection beam is wider than the beamwidth of the first detection beam, and the detection range of the second detection beam at least partially covers the near-field blind zone of the first detection beam.

[0069] Unlike traditional radar designs that typically fix the radar to a single, optimal operating frequency in pursuit of stable performance, this step involves the command radar's baseband processor and radio frequency front-end (mainly including frequency synthesizers, waveform generators, and power amplifiers) working together to construct an alternating multi-frequency sequence in the time dimension.

[0070] Taking the alternating operation of a radar at a first and a second operating frequency as an example, the first operating frequency, in essence, is the specific frequency at which the radar antenna array achieves optimal or near-optimal performance. For an antenna designed for a specific frequency band, its performance parameters (such as gain, efficiency, and radiation pattern) vary with frequency. There are one or more center frequencies where the antenna's input impedance and the RF front-end's output impedance achieve conjugate matching. At this point, energy transmission efficiency is highest, the sidelobe level of the antenna pattern is low, and the main beam shape is most regular and concentrated. Therefore, choosing this frequency as the first operating frequency directly aims to form the first detection beam—a radiation beam with maximized gain, narrowest beamwidth, and most concentrated energy. This beam acts like a precise optical lens, accurately projecting energy into the far-field region, thereby achieving long-range, high signal-to-noise ratio, and high angular resolution detection, ensuring excellent system performance within conventional long-range coverage areas.

[0071] In contrast, the second operating frequency is a specific frequency selected within the radar's legal operating bandwidth but deviating from the aforementioned optimal matching center. When the radar operates at this frequency, the antenna array is in a vector-matched state. This vector-matching is not a passive manifestation of a design flaw, but rather a resource actively utilized by this invention. Due to the deviation from the optimal frequency, the impedance characteristics of the antenna elements change, causing the amplitude and phase distribution of the entire array to deviate from the ideal design. The direct physical effect of this deviation is that the main beam of the antenna pattern will be distorted, characterized by main lobe broadening, accompanied by a decrease in gain. The embodiments of this application utilize this beam broadening effect. Therefore, this frequency is selected as the second operating frequency to form a second detection beam, a radiation beam with a significantly wider beamwidth than the first detection beam but lower gain. This beam sacrifices far-field energy concentration and detection range in exchange for a wider spatial coverage on the elevation plane.

[0072] Thus, the radar controller generates a specific timing control signal based on the first and second operating frequencies, driving the frequency synthesizer to rapidly and periodically switch between the preset first and second operating frequencies. This switching is not arbitrary; it requires the RF link to stably transmit a specific waveform (such as an FMCWchirp signal) at each frequency and ensures that the receiver chain can switch to the corresponding frequency for echo reception. This process also involves precise timing synchronization to ensure that frequency switching and stabilization are completed between transmission and reception, avoiding signal distortion. The entire control loop constitutes a time-division multiplexed frame structure, where different time slices within a frame are allocated to detection tasks at different frequencies. This is a prerequisite for subsequent data fusion and a key to achieving functional enhancement without any hardware modifications.

[0073] In actual detection, the narrow beam (first detection beam) generated by the first operating frequency, due to its concentrated energy and strong directivity, has a detection range that begins at a distance from the radar installation point, thus forming a wedge-shaped region called the "near-field blind zone" between directly below the radar and this starting point. The near-field blind zone, as referred to in this application, refers to the area between the main beam's initial illumination point and the radar installation point that cannot be effectively detected due to the radar's high-position installation, beam downtilt, and limited beam width; this includes the vertical projection blind zone and the near-ground coverage blind zone.

[0074] On the other hand, the wide beam generated at the second operating frequency (the second detection beam), due to its more divergent energy on the elevation plane, can reach the ground earlier, significantly advancing the starting point of its detection range. The detection range of the second detection beam at least partially covers the near-field blind zone of the first detection beam. Spatially, this means that the effective detection area of ​​the second beam (especially its far-field boundary) extends forward, penetrating or at least partially covering the near-field blind zone that the first detection beam cannot reach. This coverage is not a simple overlap, but a functional complementarity: the narrow beam is responsible for precise surveillance at medium and long ranges, while the wide beam is specifically responsible for illuminating the dark corners left by the narrow beam. Through alternating operation, the radar system alternately plays the roles of "telescope" and "wide-angle lens" in time, providing complete target scene information for subsequent data fusion.

[0075] In related technologies, when designing millimeter-wave radar, engineers strive to avoid mismatched frequencies with poor antenna performance, operating only on the optimal normal frequency (i.e., the first operating frequency mentioned above) to ensure detection range and accuracy. This application, through the aforementioned steps, actively utilizes these mismatched frequencies (i.e., the second operating frequency mentioned above) that are rejected by traditional designs; by rapidly switching the radar between the normal and mismatched frequencies, two beams of different shapes are formed (one narrow and far-reaching, the other wide and near-reaching), thereby achieving coordinated coverage of near and far areas and effectively reducing the detection blind zone directly below the radar.

[0076] Step S320: The detection data obtained from the first detection beam and the second detection beam are fused together to generate the target detection result after the radar blind zone is reduced.

[0077] When the radar operates at its first operating frequency, the echo signal captured by its receiver undergoes a series of standard radar signal processing steps (which may include mixing, filtering, analog-to-digital conversion, etc.), and is ultimately transformed into initial detection data through algorithms such as two-dimensional fast Fourier transform (2D-FFT). This data is typically a point cloud set, where each point contains target information observed under a narrow beam angle, such as the target's radial range, radial velocity (Doppler), azimuth angle, elevation angle, and echo signal-to-noise ratio.

[0078] Similarly, when the radar operates at the second frequency, it executes another set of signal processing procedures in parallel to generate second detection data. It should be noted that since the second operating frequency may be in an antenna mismatch state, its signal quality (such as phase stability) may be inferior to that of the first frequency. Therefore, more robust algorithms (such as matched filtering) may be needed to ensure the reliability of ranging during processing.

[0079] For targets detected and successfully correlated under both beams, their information can be combined to generate a target detection result with a reduced blind zone. In the final output, reliable target information appears within the near-field blind zone originally defined by the first detection beam. This means that the effective detection boundary of the radar is pushed forward and downward at the system level, effectively expanding the radar's sensing range without adding any hardware sensors, solely through signal processing and data fusion algorithms.

[0080] Furthermore, it should be noted that although the above embodiments explicitly use "first operating frequency" and "second operating frequency" as specific implementation methods, those skilled in the art should understand that this application is not limited to specific scenarios involving only two frequencies. In essence, it covers a more general technical solution that controls the radar to operate alternately between multiple operating frequencies with different beam characteristics and fuses their detection data to reduce blind spots. The terms "first" and "second" used above are exemplary rather than exclusive descriptions of this principle.

[0081] Through steps S310 to S320, by utilizing the inherent physical characteristics of radar at different frequencies—specifically, within the operating bandwidth, a certain frequency (the second operating frequency) will exhibit beam broadening due to impedance mismatch—the radar is instructed to alternately transmit a traditional, narrow, and concentrated first detection beam (to ensure superior far-field detection capabilities) and an innovative, wide, and divergent second detection beam. This design allows the coverage of the second detection beam to extend forward, at least partially covering the near-field blind zone that the first detection beam cannot reach due to geometric obstruction and beam pointing. This effectively expands the detection space, enhancing the radar's ability to detect near-ground and ground-level targets in critical scenarios such as security and transportation, while maintaining the radar's original long-range detection performance. This achieves a low-cost, high-efficiency system performance optimization, ultimately solving the inherent near-field blind zone detection problem of high-altitude millimeter-wave radar deployment without increasing hardware costs or complexity, thus effectively addressing the issue of high radar deployment costs.

[0082] In some embodiments, before the control radar alternates between a first operating frequency and a second operating frequency, the radar blind zone reduction method may further include the following steps:

[0083] Based on the test pattern of the radar within its operating bandwidth, a first operating frequency and a second operating frequency are determined. The first operating frequency is the frequency at which the radar's antenna impedance is optimally matched, and the second operating frequency is the frequency at which the elevation beamwidth of the second detection beam reaches its maximum within the operating bandwidth.

[0084] In this step, by analyzing the radiation pattern data measured by the radar within its operating bandwidth, the frequency point with optimal antenna impedance matching is identified as the first operating frequency point. At this point, the antenna input impedance and the transmission line characteristic impedance reach their best matching state (e.g., a 50-ohm system), resulting in the minimum reflection coefficient and the highest energy transmission efficiency. Furthermore, within the same operating bandwidth, by scanning the elevation beamwidth parameters of the second detection beam corresponding to each frequency point, the frequency point that maximizes the beamwidth is determined as the second operating frequency point. A maximum elevation beamwidth typically means that at this frequency point, the antenna's radiated energy distribution in the vertical direction is more dispersed (increased half-power beamwidth). The radiation pattern test data provides direct quantitative evidence of radiation characteristics for this frequency point selection, ensuring that the frequency point selection simultaneously meets the requirements of impedance matching optimization and beam characteristics.

[0085] Through the above embodiments, the optimal frequency point for antenna impedance matching is determined as the first operating frequency point, ensuring the long-range detection performance of the normal beam. At the same time, the frequency point with the maximum elevation beamwidth is determined as the second operating frequency point, actively utilizing the antenna mismatch characteristics to form a wide beam. Thus, by actively selecting the two frequency points with the largest beamwidth difference, it is ensured that the far-field detection capability of the first detection beam and the near-field coverage potential of the second detection beam both reach their physical limits, thereby maximizing the complementary effect between the two in space and achieving the best blind zone reduction effect.

[0086] In some embodiments, determining the first and second operating frequencies based on a test pattern of the radar within its operating bandwidth may further include the following steps:

[0087] Within the operating bandwidth, test patterns are measured for multiple frequency points, and the main beamwidth for each frequency point is calculated based on the test patterns. From each main beamwidth, the first beamwidth with the narrowest beamwidth and the second beamwidth with the widest beamwidth are calculated. The frequency point corresponding to the first beamwidth is determined as the first operating frequency point, and the frequency point corresponding to the second beamwidth is determined as the second operating frequency point.

[0088] Generally, when designing and using millimeter-wave radar antennas with large frequency bands such as 59G to 64G and 76G to 81G, the radiation pattern of the radar antenna is first tested passively or actively at different frequency points. The optimal frequency point with the maximum gain and 6dB width of the radiation pattern that meets the detection requirements is selected as the frequency point for subsequent work.

[0089] Specifically, let the radar operating frequency be... Available bandwidth .by Horizontal and elevation patterns of the step measurement radar ,here Take 0.2GHz.

[0090] In each In the middle, let the maximum value of the directional pattern be... -6dB power Defined as Then find All of the above The angles, where the minimum and maximum angles are defined as... and Calculate the frequency point 6dB beamwidth in both horizontal and vertical directions .

[0091] The frequency point whose beamwidth best meets the design requirements is selected as follows. (Generally, you can choose) , , and The most frequent mismatch was (Generally, you can choose) And for and Calculate the 6dB beamwidth. and .

[0092] Define frequency point The maximum detection range and half-beam angle of the antenna are respectively and ,choose The highest frequency point is selected as the first operating frequency point. The highest frequency is used as the second operating frequency. The lower beam is responsible for long-range detection. The lower beam is responsible for near-field blind spot coverage.

[0093] Through the above embodiments, by systematically measuring the antenna pattern and selecting dual operating frequencies based on the extreme value of the main beamwidth, the beam mismatch broadening characteristic, which is considered a defect in traditional design, is transformed into a controllable detection resource. This enables a single radar hardware to automatically possess the dual capabilities of narrow-beam long-range detection and wide-beam near-field coverage, thereby solving the inherent blind zone problem of high-position radar and achieving effective expansion of the detection range with zero hardware modification cost.

[0094] In some embodiments, the radar blind zone reduction method described above may further include the following steps:

[0095] Based on the test pattern, at least one third beamwidth is determined between the first and second beamwidths; based on the third beamwidth, at least one corresponding third operating frequency is determined; wherein, the radar operates alternately between the first, second, and third operating frequencies.

[0096] Specifically, based on the established boundary characteristic frequencies of "narrowest" (first beamwidth) and "widest" (second beamwidth), and using a test pattern dataset, one or more intermediate values ​​(i.e., third beamwidths) between these two extreme values ​​are searched for. These intermediate beamwidths precisely fill the transition region between the narrow beam far field and the wide beam near field in terms of spatial coverage. Subsequently, through reverse mapping, each selected third beamwidth is associated with the specific frequency at which it was generated, thereby determining at least one third operating frequency. Finally, the radar system's waveform controller is configured to alternate between the frequency set consisting of the first, second, and third operating frequencies in a predetermined sequence. This allows the radar to dynamically generate a set of detection beams with a stepped beamwidth distribution, thereby achieving more continuous, refined, and blind-zone-free coordinated detection of the target space from the near field to the far field.

[0097] It should also be understood that there can be one or more of the aforementioned third operating frequencies; theoretically, the more frequencies there are, the wider the beam coverage and the larger the radar detection range.

[0098] In some embodiments, the control radar operates alternately between a first operating frequency and a second operating frequency, and may further include the following steps:

[0099] The radar acquires a first pulse count and a second pulse count; the first pulse count is greater than the second pulse count; a first subframe is constructed based on the first pulse count and a first operating frequency; and a second subframe is constructed based on the second pulse count and the second operating frequency; an interleaved frame waveform is constructed based on the first subframe and the second subframe; the radar alternates between the first operating frequency and the second operating frequency by transmitting the interleaved frame waveform.

[0100] This step primarily involves constructing the transmission waveform and enabling wave transmission. Specifically, two different chirp pulse quantity parameters are first configured, with the first pulse quantity (N) being significantly larger than the second pulse quantity (usually set to 1). This determines the basic resource allocation for the two detection modes. Based on the first pulse quantity and the first operating frequency, a first subframe (Frame A) for conventional detection is constructed. The multiple chirp pulses contained within provide the data foundation for subsequent Doppler FFT processing, thereby achieving high-precision velocity measurement and long-range target detection. Simultaneously, based on a minimal second pulse quantity and the second operating frequency, a second subframe (Frame B) dedicated to blind zone detection is constructed. A single chirp pulse in Frame B only needs to perform coarse ranging, minimizing time overhead. By splicing the first and second subframes in a predetermined order along the time axis, a periodic interleaved frame waveform is constructed.

[0101] The waveform of the interleaved frame is as follows Figure 4As shown in the figure, the time-frequency structure arrangement of signal frames in a beam-enhanced blind zone reduction method is illustrated. The system alternates between Frame A and Frame B on the time axis. Each frame contains a first subframe Frame A with N linear frequency modulated pulses (chirps) and a second subframe Frame B with a single chirp. By allocating different frequencies or available bandwidth resources in different time periods, the enhanced coverage and detection range of the blind zone signal are achieved, thereby improving the sensing capability of radar or communication systems in traditional blind zones.

[0102] In this way, when the radar radio frequency front end operates according to this interleaved frame waveform, it automatically alternates between the first operating frequency (transmit Frame A) and the second operating frequency (transmit Frame B), which not only ensures that the performance of the main detection mission is not affected, but also completes near-field blind zone coverage at the lowest resource cost.

[0103] In some embodiments, calculating the detection range of the second detection beam may further include the following steps:

[0104] Based on the radar's installation height and downtilt angle, the near-field blind zone boundary of the first detection beam is calculated; based on the near-field blind zone boundary, the horizontal detection maximum distance of the second detection beam is calculated, and the detection range of the second detection beam is determined according to the horizontal detection maximum distance; wherein, the horizontal detection maximum distance is the maximum distance of the intersection point formed by the second detection beam on the ground.

[0105] In this embodiment, to avoid affecting the radar's original normal detection capabilities and results, the mismatch waveform needs to be specially designed to avoid detection results from the normal waveform. Therefore, a method for calculating the detection range of the mismatch beam, i.e., the aforementioned second detection beam, is provided. Specifically, to simplify the calculation, for each frequency... 6dB beamwidth half beamwidth The calculation process is shown in the following formula:

[0106] ;

[0107] For a better understanding of this application, please refer to Figure 5 The radar deployed in a high-mounted mounting configuration has an installation height of H above the ground. This installation height H, the maximum detection range MAX_RANGE, and the maximum horizontal detection range L form a right triangle. The angle between the maximum detection range MAX_RANGE as the centerline and the beamwidth boundary line is the 6dB beamwidth θ; the angle between this centerline and the horizontal line where the radar is installed is the radar downtilt angle α.

[0108] If the installation standard is based on the radar beam center pointing towards the ground, then according to Figure 5 The relationship between the radar downtilt angle α and the installation height H can be calculated, as shown in the following formula:

[0109] ;

[0110] ;

[0111] In the above formula, h represents the height of the target being detected. Figure 5 For example, h=0 at this time.

[0112] When the radar detection area is in the far field of the antenna, the blind zone can be simply considered to be outside the radar's 6dB beamwidth. Therefore, the formula for calculating the distance l between the beam and the nearest ground focus point and the vertical projection of the radar installation location onto the ground (blind zone) is:

[0113] ;

[0114] It is evident that the horizontal blind zone distance *l* is closely related to the installation height *H*, the downtilt angle *α*, and the half-beam angle *θ*. When the installation height *H* and the downtilt angle *α* are fixed, the change in the horizontal blind zone distance *l* is only related to the half-beam angle *θ*.

[0115] Specifically, when the installation height H and downtilt angle α are fixed, different frequency points affect the antenna beamwidth, indirectly affecting the size of the dead zone. When selecting a frequency point... and At that time, the corresponding blind zones (the points where the beam intersects with the ground) are as follows:

[0116] ;

[0117] ;

[0118] Based on this, in order to use the second detection beam to compensate for the radar blind zone caused above, it is necessary to derive the farthest intersection point between the second detection beam and the ground during its extension based on the obtained blind zone boundary position. The horizontal distance of this point is the farthest horizontal detection distance of the second detection beam. Finally, by determining the interval from the near-field blind zone boundary to this farthest horizontal detection distance, the effective detection range of the second detection beam is precisely defined in the horizontal dimension, achieving continuous coverage from the outer edge of the blind zone to the far-field region.

[0119] In some embodiments, the maximum horizontal detection distance of the second detection beam is equal to the near-field blind zone boundary of the first detection beam.

[0120] Among these considerations, given that the normal beam, i.e., the first detection beam mentioned above, meets the detection requirements, the crucial step is to compensate for the normal beam's shortcomings by utilizing the detection range of the mismatched beam. Please refer to [link / reference needed]. Figures 6A to 6C The detection range of three different mismatched beams (i.e., the second detection beam mentioned above) and normal beams (i.e., the first detection beam mentioned above) is shown respectively. Figure 6A The maximum horizontal detection distance of the mismatched beam shown is a certain distance from the boundary between the normal beam and the ground (i.e., the near-field blind zone boundary), resulting in a blind zone between the coverage areas of the two beams, which is not convenient for post-processing. Figure 6B The two beams meet precisely on the ground, effectively reducing the original beam's blind spot. Figure 6C In addition to reducing the ground blind zone, the extra beam velocity detection range of the mismatched beam can introduce more interference, thereby increasing the complexity of subsequent processing.

[0121] therefore, Figure 6B The scenario shown represents a relatively ideal detection condition, where the distant detection edge of the mismatched beam precisely covers the blind zone of the normal beam. Based on the derived formula above, the maximum detection range of the mismatched beam can be calculated as follows:

[0122] ;

[0123] This determines the detection range of the second detection beam.

[0124] Through the above embodiments, by precisely controlling the maximum horizontal detection distance of the second detection beam (mismatched beam) to completely overlap with the near-field blind zone boundary of the first detection beam (normal beam), a seamless connection of the detection ranges of the two beams on the ground is achieved. Thus, without leaving any coverage blind zone or introducing any extra detection range, the near-field blind zone of the first beam is reduced in an optimized way, significantly improving the overall detection continuity of the system. At the same time, it avoids the problem of increased post-processing complexity caused by additional interference introduced due to excessive beam overlap.

[0125] In some embodiments, the above-mentioned method of fusing the detection data obtained from the first and second detection beams to generate a target detection result with reduced radar blind zone may further include the following steps:

[0126] For the echo signal received at the second operating frequency, a matched filtering algorithm is used for target distance detection. The target point cloud data obtained based on the matched filtering algorithm is then merged with the target point cloud data obtained by fast Fourier transform at the first operating frequency to obtain the target detection result.

[0127] First, it should be noted that conventional millimeter-wave radars use the Fast Fourier Transform (FFT) method to perform target ranging, velocity measurement, and angle measurement. However, due to problems such as unmatched waveform phase instability and excessive ground clutter, the FFT calculation results are not ideal. Therefore, the matched filtering method is chosen to perform target ranging.

[0128] If the transmitted signal is defined as Then construct a matched filter. Matched filtering results for:

[0129] ;

[0130] In the formula, This is a convolution operation. The result... The target distance can be obtained by finding the maximum value. The calculation methods for the remaining target information are consistent with the conventional millimeter-wave calculation methods.

[0131] In this way, millimeter-wave radar measures the target area, and the radial distance of each measurement point can be obtained in each frame. Doppler velocity Horizontal angle Pitch angle and signal-to-noise ratio , that is:

[0132] ;

[0133] Because the radar has a high repetition frequency for each frame and a long time interval between adjacent frames... Shorter. The radar alternates between operating frequencies across different frames and fuses the detection results:

[0134] ;

[0135] In the formula, Frequency point and The measurement set. For example, Figure 7 The image shows the frame fusion process of the detection results of the first detection beam at different frequency points and the detection results of the second detection beam; the points in each detection beam are used to represent the detected measurement points.

[0136] After optimization using interleaving of normal beams and mismatched beams, the detection results are as follows: Figure 8A and Figure 8B .in, Figure 8A The diagram shows the radar measuring the target point using the first detection beam (i.e., the normal beam) before optimization, where the maximum horizontal distance of the blind zone is l. Figure 8BThis shows a schematic diagram of the optimized radar using the first and second detection beams (i.e., the mismatched beams) to alternately measure the target point. At this time, the maximum horizontal distance of the blind zone is reduced to l'.

[0137] Through the above embodiments, by using a matched filtering algorithm to perform high-precision target distance detection on the echo signal at the second operating frequency, the detection capability and ranging accuracy of targets in weak signals or complex environments can be effectively improved. Furthermore, the fine target point cloud data obtained in this way is fused with the point cloud data obtained by fast Fourier transform at the first operating frequency, realizing the complementarity of the advantages of different frequencies and different processing algorithms. Finally, a more comprehensive, more accurate target detection result with less redundant information is generated, which significantly enhances the overall perception performance and reliability of the system in complex scenarios.

[0138] The present application will now be described and illustrated with reference to specific embodiments. Figure 9 This is a flowchart of another radar blind zone reduction method according to an embodiment of this application, such as... Figure 9 As shown, the process includes the following steps:

[0139] Step S901: Perform horizontal and pitch pattern tests at different frequencies.

[0140] Step S902: Calculate the 6dB beamwidth for the horizontal and pitch patterns.

[0141] In step S903, the chip performs optimal detection at a first operating frequency for distant locations and at a second operating frequency for mismatched detection blind zones.

[0142] Step S904, waveform design and construction; wherein, based on the first operating frequency and the second operating frequency, an interleaved wave waveform is constructed and the wave is enabled to be generated.

[0143] Step S905 involves target ranging and velocity measurement, as well as mismatch waveform detection. Specifically, the radar emits interleaved waves, and the resulting first detection beam is used for target ranging and velocity measurement, while the second detection beam, i.e., the mismatch waveform, is used to supplement the detection blind zone.

[0144] Step S906: The detection results of different frequency frames are fused, and the final detection result is output.

[0145] The following explanation will focus on specific application scenarios. Taking a comb antenna in the 59-64GHz band as an example, the horizontal and elevation radiation patterns measured in an anechoic chamber at 60GHz (the frequency of the mismatched beam) and 62.5GHz (the frequency of the normal beam) are shown below. Figure 10 As shown, the orange radiation pattern at 62.5 GHz meets the design requirements, while the blue radiation pattern at 60 GHz represents a mismatch. Therefore, in this example, GHz, GHz. It can be observed that both frequency points are within the permitted range according to regulations, and there are significant differences in the radar's horizontal and elevation patterns at these two frequency points.

[0146] Studying only the pitch pattern, such as Figure 11 As shown, the orange-lit 62.5GHz beamwidth at 6dB elevation is 12.0°, while the blue-lit mismatched 60GHz beamwidth at 6dB elevation is 24.1°. Please refer to [link to relevant documentation] next. Figure 12 In the figure, the horizontal axis represents the horizontal distance (m), the vertical axis represents the height (m), and the area enclosed by the green line is the mismatch detection area, while the area within the blue line is the normal detection area. Therefore, when the radar is installed at a height of 4m and the downward tilt angle is 1°, the blind zone is calculated to be 17.3m and 8.6m respectively.

[0147] Make the radar in and By alternately transmitting probe waveforms on the same frequency and receiving them at the receiver, the elevation pattern can be equivalent to... Figure 11 The composite radiation pattern is shown in the image, and the detection blind zone has been reduced from 17.3m to 8.6m.

[0148] As can be seen, after frame fusion detection of F1 and F2, the pitch blind zone was reduced from 17.3m to 8.6m, a reduction of 50%, and the effective detection area was increased by 8.67%. This means that without any changes or additions to the hardware solution, the area that originally required 12 devices to effectively cover can now be covered by only 11 devices.

[0149] In conventional radar detection, the mismatch waveform is a frequency that the radar needs to avoid when selecting the operating frequency. Its waveform and detection capability are inherent design flaws that need to be avoided in conventional radar design. However, this application cleverly utilizes this radar flaw to supplement the blind zone.

[0150] This application utilizes frequency switching to enable the radio frequency link to transmit signals at different frequencies. Since millimeter-wave radar antennas typically exhibit some degree of mismatch or distortion at non-optimal frequencies—an inherent physical characteristic of antenna radio frequency—this method can achieve physical-level beam distortion of the radar through software to improve detection performance. This improvement is independent of and does not conflict with the enhancements provided by other algorithms.

[0151] By utilizing the impedance mismatch characteristic of antenna design at edge frequencies within the regulated bandwidth, and combining waveform design and tracking algorithms, near-field blind zone detection can be achieved. Without changing the hardware, only software upgrades are needed to reduce the blind zone.

[0152] This solution does not require much additional development resources. It uses the time interval in normal beam alternation to send mismatched waveforms. The time and space consumption of the algorithm are less than the resources required for normal waveform detection, and no additional FLASH and memory resources are needed.

[0153] It should be noted that the steps shown in the above process or in the flowchart of the accompanying figures can be executed in a computer system such as a set of computer-executable instructions, and although a logical order is shown in the flowchart, in some cases the steps shown or described may be executed in a different order than that shown here.

[0154] This embodiment also provides a radar system for implementing the above embodiments and preferred embodiments, which will not be repeated hereafter. As used below, the terms "module," "unit," "subunit," etc., can refer to a combination of software and / or hardware that performs a predetermined function. Although the apparatus described in the following embodiments is preferably implemented in software, hardware implementation, or a combination of software and hardware, is also possible and contemplated.

[0155] Figure 13 This is a structural block diagram of a radar system according to an embodiment of this application, such as... Figure 13 As shown, the device includes:

[0156] The beam control unit 10 is used to control the radar to work alternately between a first operating frequency and a second operating frequency; the first operating frequency is used to form a first detection beam, and the second operating frequency is used to form a second detection beam; wherein the beamwidth of the second detection beam is wider than the beamwidth of the first detection beam, and the detection range of the second detection beam at least partially covers the near-field blind zone of the first detection beam.

[0157] The data processing unit 20 is used to fuse the detection data obtained from the first detection beam and the second detection beam respectively, and generate the target detection result after the radar blind zone is reduced.

[0158] It should be noted that the above modules can be functional modules or program modules, and can be implemented by software or hardware. For modules implemented by hardware, the above modules can reside in the same processor; or the above modules can be located in different processors in any combination. Specific examples in this embodiment can be found in the examples described in the above embodiments and optional implementations, and will not be repeated in this embodiment.

[0159] This embodiment also provides an electronic device, including a memory and a processor, wherein the memory stores a computer program and the processor is configured to run the computer program to perform the steps in any of the above method embodiments.

[0160] Optionally, the electronic device may further include a transmission device and an input / output device, wherein the transmission device is connected to the processor and the input / output device is connected to the processor.

[0161] Optionally, in this embodiment, the processor can be configured to perform the following steps via a computer program:

[0162] S1, the control radar alternates between a first operating frequency and a second operating frequency; the first operating frequency is used to form a first detection beam, and the second operating frequency is used to form a second detection beam; wherein, the beamwidth of the second detection beam is wider than the beamwidth of the first detection beam, and the detection range of the second detection beam at least partially covers the near-field blind zone of the first detection beam.

[0163] S2, fuses the detection data obtained from the first and second detection beams respectively, and generates the target detection result after the radar blind zone is reduced.

[0164] It should be noted that the specific examples in this embodiment can refer to the examples described in the above embodiments and optional implementations, and will not be repeated here.

[0165] Furthermore, in conjunction with the radar blind zone reduction methods in the above embodiments, this application embodiment can provide a storage medium for implementation. This storage medium stores a computer program; when executed by a processor, the computer program implements any of the radar blind zone reduction methods in the above embodiments.

[0166] 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, data stored, data displayed, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties.

[0167] Those skilled in the art will understand that all or part of the processes in the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium. When executed, the computer program can include the processes of the embodiments described above. Any references to memory, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile 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. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM). The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the embodiments provided in this application may be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, etc., and are not limited to these.

[0168] Those skilled in the art should understand that the technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments have been 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 specification.

[0169] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A method for reducing radar blind zone, characterized in that, The method includes: The control radar operates alternately between a first operating frequency and a second operating frequency; the first operating frequency is used to form a first detection beam, and the second operating frequency is used to form a second detection beam. Wherein, the beamwidth of the second detection beam is wider than the beamwidth of the first detection beam, and the detection range of the second detection beam at least partially covers the near-field blind zone of the first detection beam; The detection data obtained from the first detection beam and the second detection beam are fused together to generate the target detection result after the blind zone of the radar is reduced.

2. The radar blind zone reduction method according to claim 1, characterized in that, Before the control radar alternates between a first operating frequency and a second operating frequency, the method further includes: Based on the test radiation pattern of the radar within its operating bandwidth, the first operating frequency and the second operating frequency are determined; the first operating frequency is the frequency at which the antenna impedance of the radar is optimally matched, and the second operating frequency is the frequency at which the elevation beamwidth of the second detection beam reaches its maximum within the operating bandwidth.

3. The radar blind zone reduction method according to claim 2, characterized in that, The step of determining the first operating frequency and the second operating frequency based on the test pattern of the radar within its operating bandwidth includes: Within the operating bandwidth, test patterns corresponding to multiple frequency points are measured, and the main beamwidth of each frequency point is calculated based on the test patterns; Calculate the first beamwidth with the narrowest beamwidth and the second beamwidth with the widest beamwidth from each of the main beamwidths. The frequency point corresponding to the first beamwidth is determined as the first operating frequency point; The frequency point corresponding to the second beamwidth is determined as the second operating frequency point.

4. The radar blind zone reduction method according to claim 3, characterized in that, The method further includes: Based on the test pattern, at least one third beamwidth is determined where the main beamwidth is between the first beamwidth and the second beamwidth; Based on the third beamwidth, at least one corresponding third operating frequency point is determined; The radar operates alternately between a first operating frequency, a second operating frequency, and a third operating frequency.

5. The radar blind zone reduction method according to claim 1, characterized in that, The control radar operates alternately between a first operating frequency and a second operating frequency, including: Obtain the first pulse count and the second pulse count; the first pulse count is greater than the second pulse count. Based on the first pulse count and the first operating frequency, a first subframe is constructed; and, Based on the second pulse number and the second operating frequency, a second subframe is constructed; Based on the first subframe and the second subframe, an interleaved frame waveform is constructed; the radar operates alternately between the first operating frequency and the second operating frequency by transmitting the interleaved frame waveform.

6. The radar blind zone reduction method according to claim 1, characterized in that, Calculating the detection range of the second detection beam includes: The near-field blind zone boundary of the first detection beam is calculated based on the installation height and downtilt angle of the radar. Based on the near-field blind zone boundary, the horizontal detection maximum distance of the second detection beam is calculated, and the detection range of the second detection beam is determined according to the horizontal detection maximum distance; wherein, the horizontal detection maximum distance is the maximum distance of the intersection point formed by the second detection beam on the ground.

7. The radar blind zone reduction method according to claim 6, characterized in that, The maximum horizontal detection distance of the second detection beam is equal to the near-field blind zone boundary of the first detection beam.

8. The radar blind zone reduction method according to any one of claims 1 to 7, characterized in that, The process of fusing the detection data obtained from the first detection beam and the second detection beam, and generating the target detection result with reduced blind zone of the radar, includes: For the echo signal received at the second operating frequency, a matched filtering algorithm is used for target distance detection; The target point cloud data obtained based on the matched filtering algorithm is merged with the target point cloud data obtained by fast Fourier transform at the first operating frequency to obtain the target detection result.

9. A radar system, characterized in that, include: A beam control unit is used to control the radar to operate alternately between a first operating frequency and a second operating frequency; the first operating frequency is used to form a first detection beam, and the second operating frequency is used to form a second detection beam. Wherein, the beamwidth of the second detection beam is wider than the beamwidth of the first detection beam, and the detection range of the second detection beam at least partially covers the near-field blind zone of the first detection beam; The data processing unit is used to fuse the detection data obtained from the first detection beam and the second detection beam respectively, and generate the target detection result after the blind zone of the radar is reduced.

10. A storage medium, characterized in that, The storage medium stores a computer program, wherein the computer program is configured to execute the radar blind zone reduction method according to any one of claims 1 to 8 when it is run.

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