Radar ranging method, device and equipment and storage medium

Abstract

The invention provides a radar ranging method and device, equipment and a storage medium, and relates to the technical field of radar detection precision optimization. The method comprises the steps that two groups of frequency hopping chirp signals are controlled to be transmitted in a single frame in a staggered mode, starting frequencies of the signals are different, and the total bandwidth of single-group frequency hopping is larger than the bandwidth of a single chirp signal; receiving echo signals respectively corresponding to the two groups of frequency hopping linear frequency modulation signals, and performing frequency mixing processing on each group of frequency hopping linear frequency modulation signals and the corresponding echo signals to obtain two groups of intermediate frequency signals; determining initial first speed information and corrected second speed information corresponding to the detection target based on the two groups of intermediate frequency signals; and determining the distance of the detection target based on the first speed information, the second speed information and the signal parameters of the two groups of frequency hopping linear frequency modulation signals. According to the method, the two groups of frequency hopping linear frequency modulation signals are transmitted in the single frame in a staggered manner, so that the equivalent bandwidth is increased, the distance measurement resolution is remarkably improved, and the distance measurement precision is greatly improved.

Description

Technical Field

[0001] The present application relates to the technical field of radar detection accuracy optimization, and in particular to a radar ranging method, apparatus, device and storage medium. Background Art

[0002] In recent years, with the rapid development of autonomous driving and intelligent transportation systems, environmental perception technology has become the core foundation for safe vehicle decision-making. Radar, especially millimeter-wave radar, has become one of the core sensors in intelligent vehicle environmental perception systems due to its all-weather adaptability, strong anti-interference performance, and high cost-performance. As the level of autonomous driving increases, vehicles must achieve millimeter-level precision ranging to obstacles in complex scenarios such as highway lane changes, urban congestion, and ramp merging. This is to support real-time response to key functions such as adaptive cruise control, emergency braking, and automatic lane change. Therefore, the ranging accuracy of millimeter-wave radar directly affects the vehicle's ability to spatially locate surrounding obstacles, and thus the decision-making reliability and safety of the autonomous driving system.

[0003] In related technologies, a radar transmit antenna typically emits a continuous wave signal whose frequency varies linearly with time. When the transmitted signal encounters a target, it is reflected and received by the radar's receiving antenna. The received echo signal is mixed with the transmitted signal in a mixer to generate an intermediate frequency (IF) signal. The IF signal is then sampled and Fourier transformed to obtain its spectrum. The frequency corresponding to the peak in the spectrum is the IF signal's frequency. Furthermore, the distance between the radar and the target is determined based on the IF signal's frequency. However, this suffers from low ranging accuracy. Summary of the Invention

[0004] The present application provides a radar ranging method, apparatus, device and storage medium for improving the ranging accuracy of radar.

[0005] In a first aspect, the present application provides a radar ranging method, comprising:

[0006] Controlling the interleaving transmission of two sets of frequency hopping linear frequency modulation signals within a single frame, wherein the starting frequencies of the two sets of frequency hopping linear frequency modulation signals are different, and the total bandwidth of a single set of frequency hopping signals is greater than the bandwidth of a single linear frequency modulation signal;

[0007] receiving echo signals corresponding to two sets of frequency-hopping linear frequency modulation signals, and mixing each set of frequency-hopping linear frequency modulation signals with its corresponding echo signal to obtain two sets of intermediate frequency signals;

[0008] Determine the initial first speed information and the corrected second speed information corresponding to the detected target based on the two sets of intermediate frequency signals;

[0009] The distance of the detected target is determined based on the first speed information, the second speed information and the signal parameters of the two sets of frequency-hopping linear frequency modulation signals.

[0010] In one possible implementation, the signal parameters include a transmission period of a linear frequency modulation signal, a starting frequency of a frequency-hopping linear frequency modulation signal, and a frequency hopping interval. Based on the first speed information, the second speed information, and the signal parameters of the two sets of frequency-hopping linear frequency modulation signals, determining the distance to the detection target includes: determining a difference between the first speed information and the second speed information to obtain a speed difference; determining the product of the speed difference, the transmission period of the linear frequency modulation signal, and the starting frequency of the frequency-hopping linear frequency modulation signal to obtain a target value; and determining the ratio of the target value to the frequency hopping interval as the distance to the detection target.

[0011] In one possible implementation, determining initial first velocity information and corrected second velocity information corresponding to a detected target based on two sets of intermediate frequency signals includes: performing a two-dimensional fast Fourier transform (2D-FFT) on each of the two sets of intermediate frequency signals to obtain a first range-Doppler map and a second range-Doppler map corresponding to the two sets of intermediate frequency signals, respectively; determining the detected target in the first range-Doppler map and the second range-Doppler map, as well as the initial first velocity information corresponding to the detected target; obtaining first initial phase information of the detected target in the first range-Doppler map and second initial phase information of the detected target in the second range-Doppler map; and determining the corrected second velocity information based on the first initial phase information and the second initial phase information.

[0012] In one possible implementation, determining the corrected second velocity information based on the first initial phase information and the second initial phase information includes: determining the phase difference of the detection target at the corresponding position based on the first initial phase information and the second initial phase information; obtaining Doppler information of the detection target based on the phase difference; and determining the corrected second velocity information based on the Doppler information and signal parameters.

[0013] In one possible implementation, determining the detection target in the first range-Doppler map and the second range-Doppler map includes: using a Constant False-Alarm Rate (CFAR) algorithm to identify the detection target in the first range-Doppler map and the second range-Doppler map.

[0014] In one possible implementation, the radar ranging method further includes: monitoring the noise level and clutter characteristics of the radar's current operating environment; evaluating statistical characteristics of the noise and clutter based on the noise level and clutter characteristics; and adjusting a detection threshold, a number of protection units, and a number of reference units of a CFAR algorithm based on the statistical characteristics.

[0015] In one possible implementation, a single linear frequency modulation signal satisfies the formula:

[0016]

[0017]

[0018] in, is the i-th linear frequency modulation signal in a single set of frequency hopping linear frequency modulation signals, t is the time variable; j is the imaginary unit; Δf is the frequency hopping step; μ is the frequency modulation slope of the linear frequency modulation signal; f0 is the starting frequency of the first linear frequency modulation signal transmitted; f h is the frequency difference between the starting frequency of the second linear frequency modulation signal and the starting frequency of the first linear frequency modulation signal; n = 0, 1, 2, …, N-1, where N is a positive integer greater than 1.

[0019] In a second aspect, the present application provides a radar ranging device, comprising:

[0020] A transmitting module, configured to control the interleaved transmission of two sets of frequency-hopping linear frequency modulation signals within a single frame, wherein the starting frequencies of the two sets of frequency-hopping linear frequency modulation signals are different, and the total bandwidth of a single set of frequency-hopping linear frequency modulation signals is greater than the bandwidth of a single linear frequency modulation signal;

[0021] The receiving module is used to receive the echo signals corresponding to the two sets of frequency-hopping linear frequency modulation signals, and mix each set of frequency-hopping linear frequency modulation signals with its corresponding echo signal to obtain two sets of intermediate frequency signals;

[0022] A first processing module is configured to determine initial first velocity information and corrected second velocity information corresponding to the detected target based on the two sets of intermediate frequency signals;

[0023] The second processing module is configured to determine a distance to a detected target based on the first speed information, the second speed information, and signal parameters of two sets of frequency-hopping linear frequency modulation signals.

[0024] In a third aspect, the present application provides an electronic device, comprising: a processor, and a memory communicatively connected to the processor;

[0025] Memory for storing computer-executable instructions;

[0026] A processor is used to execute computer-executable instructions stored in the memory to implement the radar ranging method described in any one of the first aspects.

[0027] In a fourth aspect, the present application provides a computer-readable storage medium, which stores computer-executable instructions. When the computer-executable instructions are executed, they are used to implement the radar ranging method described in any one of the first aspects.

[0028] In a fifth aspect, the present application provides a computer program product, comprising a computer program, which, when executed, implements the radar communication method described in any one of the first aspects.

[0029] The radar ranging method, apparatus, device, and storage medium provided in the present application control the interleaved transmission of two sets of frequency-hopping linear frequency modulation signals within a single frame, wherein the starting frequencies of the two sets of frequency-hopping linear frequency modulation signals are different, and the total bandwidth of a single set of frequency-hopping linear frequency modulation signals is greater than the bandwidth of a single linear frequency modulation signal; receive echo signals corresponding to the two sets of frequency-hopping linear frequency modulation signals, and mix each set of frequency-hopping linear frequency modulation signals with its corresponding echo signal to obtain two sets of intermediate frequency signals; determine initial first speed information and corrected second speed information corresponding to the detected target based on the two sets of intermediate frequency signals; and determine the distance of the detected target based on the first speed information, the second speed information, and signal parameters of the two sets of frequency-hopping linear frequency modulation signals. In this process, by interleaving the transmission of two groups of frequency-hopping linear frequency modulation signals with different starting frequencies and a total frequency-hopping bandwidth greater than the bandwidth of a single linear frequency modulation signal within a single frame, the equivalent bandwidth is increased, the ranging resolution is significantly improved, and thus the ranging accuracy is greatly improved, and the risk of misjudgment or missed detection is significantly reduced, thereby providing a more accurate perception basis for intelligent driving technology; in addition, compared with conventional large-bandwidth linear frequency modulation signals, frequency-hopping linear frequency modulation signals have stronger anti-interference capabilities, can work stably in complex electromagnetic environments, and can also reduce the amount of sampling data and data processing time, which helps to improve data processing efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0031] Figure 1 A schematic flow chart of a radar ranging method provided by an exemplary embodiment of the present application;

[0032] Figure 2 A schematic diagram of two sets of frequency-hopping linear frequency modulation signals provided by an exemplary embodiment of the present application;

[0033] Figure 3 Another schematic flow chart of a radar ranging method provided by an exemplary embodiment of the present application;

[0034] Figure 4 Schematic diagram of ranging results corresponding to conventional linear frequency modulation radar in related technology;

[0035] Figure 5 A schematic diagram of ranging results corresponding to a frequency-hopping linear frequency modulation radar provided in an exemplary embodiment of the present application;

[0036] Figure 6A schematic structural diagram of a radar ranging device provided by an exemplary embodiment of the present application;

[0037] Figure 7 A schematic structural diagram of an electronic device provided as an exemplary embodiment of the present application.

[0038] The above drawings illustrate specific embodiments of the present application, which will be described in more detail below. These drawings and the textual description are not intended to limit the scope of the present application in any way, but rather to illustrate the concepts of the present application to those skilled in the art by reference to specific embodiments. DETAILED DESCRIPTION

[0039] Exemplary embodiments will be described in detail herein, with examples illustrated in the accompanying drawings. In the following description, when referring to the drawings, identical numerals in different figures represent identical or similar elements, unless otherwise indicated. The embodiments described in the following exemplary embodiments are not intended to represent all embodiments consistent with the present application. Rather, they are merely examples of apparatus and methods consistent with certain aspects of the present application, as detailed in the appended claims.

[0040] The terms "first", "second" etc. in the specification and claims of the present application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequential order. It should be understood that the data used in this way can be interchangeable in appropriate circumstances, so that the embodiments of the present application described herein can, for example, be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, the process, system, product or equipment comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or that are inherent to these processes, products or equipment.

[0041] 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 laws, regulations and standards, and corresponding operation entrances must be provided for users to choose to authorize or refuse.

[0042] Signal bandwidth is one of the core factors determining radar ranging resolution. According to radar ranging principles, ranging resolution is inversely proportional to signal bandwidth. However, due to limitations in bandwidth resources, signal processing algorithms, and hardware performance, conventional millimeter-wave radars have low ranging resolution. Their ranging errors are typically on the order of 0.5 to 1 meter, making them difficult to meet the sub-decimeter (<0.1 meter) ranging accuracy requirements for high-level autonomous driving. Excessive ranging errors not only lead to inaccurate target recognition but also significantly increase the risk of misjudgment or missed detection.

[0043] To address the above-mentioned issues, an embodiment of the present application provides a radar ranging solution. By interleaving the transmission of two groups of frequency-hopping linear frequency modulation signals with different starting frequencies within a single frame and a total frequency-hopping bandwidth of a single group greater than the bandwidth of a single linear frequency modulation signal, the frequency-hopping characteristic is utilized to increase the equivalent bandwidth without increasing the actual hardware bandwidth, thereby significantly improving the ranging resolution, thereby greatly improving the ranging accuracy, significantly reducing the risk of misjudgment or missed detection, and providing a more accurate perception basis for intelligent driving technology.

[0044] The following specific embodiments describe in detail the technical solution of the present application and how the technical solution of the present application solves the above-mentioned technical problems. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments. The embodiments of the present application will be described below in conjunction with the accompanying drawings.

[0045] Figure 1 A flow chart of a radar ranging method provided by an exemplary embodiment of the present application. Figure 1 As shown, the radar ranging method includes the following steps:

[0046] S101 , controlling interleaved transmission of two sets of frequency hopping linear frequency modulation signals within a single frame, wherein the two sets of frequency hopping linear frequency modulation signals have different starting frequencies, and a total bandwidth of a single set of frequency hopping linear frequency modulation signals is greater than a bandwidth of a single linear frequency modulation signal.

[0047] The radar may be a millimeter-wave radar or a radar with other high-resolution characteristics, and is not limited here. For example, within a single-frame operating cycle of the radar, two sets of 2N frequency-hopping linear frequency modulation signals are interleaved and transmitted. The two sets of frequency-hopping linear frequency modulation signals have the same bandwidth, frequency modulation slope, and frequency hopping interval, but different starting frequencies.

[0048] In some embodiments, a single linear frequency modulation signal satisfies the formula:

[0049]

[0050]

[0051] in, is the i-th linear frequency modulation signal in a single set of frequency hopping linear frequency modulation signals, t is the time variable; j is the imaginary unit; Δf is the frequency hopping step; μ is the frequency modulation slope of the linear frequency modulation signal; f0 is the starting frequency of the first linear frequency modulation signal transmitted; f h is the frequency difference between the starting frequency of the second linear frequency modulation signal and the starting frequency of the first linear frequency modulation signal; n = 0, 1, 2, …, N-1, where N is a positive integer greater than 1.

[0052] For example, Figure 2 Schematic diagram of two sets of frequency hopping linear frequency modulation signals provided by an exemplary embodiment of the present application. Figure 2 As shown, the total bandwidth of a single frequency hopping group, namely Δf×N, is greater than the bandwidth B of a single linear frequency modulation signal, and the corresponding equivalent bandwidth increases to Δf×N.

[0053] S102 : Receive echo signals corresponding to two groups of frequency-hopping linear frequency modulation signals, and mix each group of frequency-hopping linear frequency modulation signals with its corresponding echo signal to obtain two groups of intermediate frequency signals.

[0054] Among them, the echo signal refers to the signal reflected back after the radar-transmitted signal encounters the target object. The echo signal contains information such as the distance, speed, and angle of the target object; mixing processing refers to mixing two signals of different frequencies and generating new frequency components through nonlinear elements. It is often used in radar to convert high-frequency transmission signals and echo signals into intermediate-frequency signals to facilitate subsequent signal processing and analysis; intermediate-frequency signal refers to the signal with a frequency between high and low frequencies obtained after mixing processing. Intermediate-frequency signals usually have more stable characteristics and a frequency range that is easier to process.

[0055] For example, after the radar transmits two sets of frequency-hopping linear frequency modulation signals, the signals encounter the detection target in front (that is, obstacles, such as other vehicles or pedestrians) during the propagation process, and are reflected to form echo signals; the radar's receiving antenna is responsible for receiving the echo signals corresponding to the two sets of frequency-hopping linear frequency modulation signals respectively; and sending the received echo signals and the two sets of originally transmitted frequency-hopping linear frequency modulation signals to the mixer; in the mixer, each set of frequency-hopping linear frequency modulation signals is mixed with its corresponding echo signal through nonlinear effects to obtain two sets of intermediate frequency signals, which retain the relevant information of the detection target.

[0056] S103 : Determine initial first speed information and corrected second speed information corresponding to the detected target based on the two sets of intermediate frequency signals.

[0057] For example, based on any one of the two sets of intermediate frequency signals, initial first speed information corresponding to the detected target is determined; further, the first speed information is corrected in combination with the two sets of intermediate frequency signals to obtain corrected second speed information.

[0058] S104 : Determine a distance to the detected target based on the first speed information, the second speed information, and signal parameters of the two sets of frequency-hopping linear frequency modulation signals.

[0059] In some embodiments, the signal parameters include a transmission period of a linear frequency modulation signal, a starting frequency of a frequency-hopping linear frequency modulation signal, and a frequency hopping interval. Based on the first speed information, the second speed information, and the signal parameters of the two sets of frequency-hopping linear frequency modulation signals, determining the distance to the detection target includes: determining the difference between the first speed information and the second speed information to obtain a speed difference; determining the product of the speed difference, the transmission period of the linear frequency modulation signal, and the starting frequency of the frequency-hopping linear frequency modulation signal to obtain a target value; and determining the ratio of the target value to the frequency hopping interval as the distance to the detection target.

[0060] For example, the distance R of the detected target satisfies the following formula:

[0061] R = 2 × Δv × T r ×f0 / Δf

[0062] Wherein, Δv is the speed difference, that is, the difference between the first speed information and the second speed information; T r is the transmission period of the linear frequency modulation signal, f0 is the starting frequency of the frequency hopping linear frequency modulation signal; Δf is the frequency hopping interval.

[0063] The radar ranging method provided in the embodiments of the present application achieves an increase in equivalent bandwidth and significantly improves ranging resolution by interleaving the transmission of two sets of frequency-hopping linear frequency modulation signals with different starting frequencies and a total frequency-hopping bandwidth greater than the bandwidth of a single linear frequency modulation signal within a single frame. This significantly improves ranging resolution, thereby greatly improving ranging accuracy and significantly reducing the risk of misjudgment or missed detection, thereby providing a more accurate perception basis for intelligent driving technology. Compared with conventional large-bandwidth linear frequency modulation signals, frequency-hopping linear frequency modulation signals have stronger anti-interference capabilities and can operate stably in complex electromagnetic environments. They can also reduce the amount of sampled data and data processing time, helping to improve data processing efficiency. In addition, by alternately transmitting two sets of frequency-hopping linear frequency modulation signals within a single frame, data processing delay is effectively reduced and speed measurement accuracy is improved. Furthermore, speed information and signal parameters are combined to accurately determine the distance to the detected target, thereby achieving dual optimization of ranging and speed measurement accuracy.

[0064] In some embodiments, based on two groups of intermediate frequency signals, determining the initial first velocity information and the corrected second velocity information corresponding to the detection target includes: performing 2D-FFT on the two groups of intermediate frequency signals respectively to obtain the first range-Doppler map and the second range-Doppler map corresponding to the two groups of intermediate frequency signals respectively; determining the detection target in the first range-Doppler map and the second range-Doppler map, and the initial first velocity information corresponding to the detection target; obtaining the first initial phase information of the detection target in the first range-Doppler map and the second initial phase information of the detection target in the second range-Doppler map; and determining the corrected second velocity information based on the first initial phase information and the second initial phase information.

[0065] For example, a 2D-FFT is performed on a first group of intermediate frequency signals to output a first range-Doppler map corresponding to the first group of intermediate frequency signals; a 2D-FFT is performed on a second group of intermediate frequency signals to output a second range-Doppler map corresponding to the second group of intermediate frequency signals; a detection target in the first range-Doppler map and the second range-Doppler map is determined using a peak detection algorithm, and initial first velocity information corresponding to the detection target is extracted from the first range-Doppler map or the second range-Doppler map; and first initial phase information of the detection target is extracted from the first range-Doppler map, and second initial phase information of the detection target is extracted from the second range-Doppler map; further, based on the first initial phase information and the second initial phase information, information reflecting a change in the motion state of the detection target reflected by the detection target at corresponding positions of the two groups of signals is analyzed; the Doppler correlation characteristics of the detection target are derived using the information reflecting the change in the motion state of the detection target; and the initial first velocity information is corrected in combination with the parameters of the radar signal to determine the corrected second velocity information.

[0066] In the embodiment of the present application, by performing 2D-FFT on the two sets of intermediate frequency signals respectively to obtain the range-Doppler diagram, the position change of the detection target within the signal acquisition interval is fully considered, and the relevant information of the detection target can be more comprehensively analyzed, effectively reducing the error caused by single signal processing, thereby more accurately determining the initial first velocity information and the corrected second velocity information of the detection target, further reducing the speed measurement deviation, and making the corrected second velocity information closer to the true value. This not only improves the accuracy of speed measurement, but also enhances the reliability of target detection and tracking.

[0067] In some embodiments, based on the first initial phase information and the second initial phase information, the corrected second velocity information is determined, including: determining the phase difference of the detection target at the corresponding position based on the first initial phase information and the second initial phase information; obtaining the Doppler information of the detection target based on the phase difference; and determining the corrected second velocity information based on the Doppler information and signal parameters.

[0068] For example, the first initial phase information and the second initial phase information are subtracted to determine the phase difference of the detection target at the corresponding position.

[0069] Furthermore, according to the Doppler effect principle, based on the velocity and Doppler frequency shift f d The relationship between determines the speed, which satisfies the following formula:

[0070]

[0071] in, is the speed of light; is the speed, that is, the corrected second speed information.

[0072] In some embodiments, determining the detection target in the first range-Doppler map and the second range-Doppler map includes: using a CFAR algorithm to identify the detection target in the first range-Doppler map and the second range-Doppler map.

[0073] The CFAR algorithm is a technology used for target detection in radar signal processing. During radar detection, background noise and clutter can affect target detection. The CFAR algorithm dynamically adjusts the detection threshold to maintain a constant false alarm probability (i.e., the probability of incorrectly identifying noise or clutter as a target) in various noise and clutter environments. Common CFAR algorithms include Cell-Averaging Constant False Alarm Rate (CA-CFAR) and Order Statistics Constant False Alarm Rate (OS-CFAR).

[0074] For example, a CA-CFAR algorithm is used for a first range-Doppler map and a second range-Doppler map to determine a detection threshold based on a set false alarm probability. The amplitude of a cell under test (CUT) is compared with the detection threshold. If the amplitude of the cell under test is greater than the detection threshold, it is determined that a detection target exists in the cell under test, and the position of the detection target in the corresponding range-Doppler map is recorded. If the amplitude of the cell under test is less than or equal to the detection threshold, it is determined that no detection target exists in the cell under test. All cells under test in the first range-Doppler map and the second range-Doppler map are traversed and detected to determine the detection target in the first range-Doppler map and the second range-Doppler map.

[0075] Based on the above embodiments, in some embodiments, the radar ranging method further includes: monitoring the noise level and clutter characteristics of the current working environment of the radar; evaluating the statistical characteristics of the noise and clutter based on the noise level and clutter characteristics; and adjusting the detection threshold, number of protection units, and number of reference units of the CFAR algorithm based on the statistical characteristics.

[0076] For example, based on the echo signal, the noise level and clutter intensity are extracted. Frequency domain characteristics are analyzed using FFT to distinguish moving targets from static clutter (such as guardrails and adjacent vehicles). The mean and standard deviation of the noise are calculated, and the spatial density (such as the number of strong reflection points per unit distance) and amplitude distribution of the clutter are calculated, assuming that the current ambient noise follows a Rayleigh distribution. If the clutter peak value is found to be approximately 15 dB higher than that on open roads, a noise PDF (probability density function) and the false alarm probability parameter required for clutter CFAR detection are generated. Based on the noise standard deviation, the threshold coefficient is adjusted from the initial value (such as 3.0 for open roads) to a value adapted to high-clutter sections, such as 4.5, to maintain the false alarm probability parameter. Furthermore, the detection threshold of the CFAR algorithm is determined based on the adjusted threshold coefficient and noise standard deviation. For example, when the threshold coefficient is adjusted to 4.5 and the noise standard deviation is 3 dB, the detection threshold T = 4.5 × 3 = 13.5 dB. Accordingly, for dense target scenarios, such as densely packed vehicles on congested roads, the number of protection units needs to be increased to reduce the interference of adjacent vehicle echoes on the target to be detected, for example, increasing the number of protection units from 8 to 12. In the clutter edge area, the accuracy of background estimation will be affected due to the uneven distribution of clutter. At this time, the number of reference units can be increased, for example, from an initial value such as 24 to a value adapted to the clutter edge area such as 32. By increasing the reference unit window, more background information can be included, which can help improve the accuracy of background estimation and thus more accurately calculate the detection threshold.

[0077] In the embodiments of the present application, by real-time monitoring of the noise level and clutter characteristics of the current working environment, evaluating the statistical characteristics of the noise and clutter based on the monitoring results, and dynamically adjusting the detection threshold, number of protection units, and number of reference units of the CFAR algorithm based on the evaluation results, the interference of complex environments on detection of detection targets can be effectively reduced, and the accuracy of detection target recognition can be significantly improved.

[0078] Figure 3 Another flow chart of the radar ranging method provided by the exemplary embodiment of the present application. Figure 3 As shown, the radar ranging method includes the following steps:

[0079] S301 , controlling the interleaved transmission of two groups of frequency hopping linear frequency modulation signals within a single frame, wherein the two groups of frequency hopping linear frequency modulation signals have different starting frequencies, and the total bandwidth of a single group of frequency hopping linear frequency modulation signals is greater than the bandwidth of a single linear frequency modulation signal.

[0080] For example, a single linear frequency modulation signal satisfies the formula:

[0081]

[0082]

[0083] in, is the i-th linear frequency modulation signal in a single set of frequency hopping linear frequency modulation signals, t is the time variable; j is the imaginary unit; Δf is the frequency hopping step; μ is the frequency modulation slope of the linear frequency modulation signal; f0 is the starting frequency of the first linear frequency modulation signal transmitted; f h is the frequency difference between the starting frequency of the second linear frequency modulation signal and the starting frequency of the first linear frequency modulation signal; n = 0, 1, 2, …, N-1, where N is a positive integer greater than 1.

[0084] Accordingly, refer to Figure 2 , the total bandwidth of a single frequency hopping group is Δf×N. The total bandwidth of a single frequency hopping group is greater than the bandwidth B of a single linear frequency modulation signal, and the corresponding equivalent bandwidth increases to Δf×N.

[0085] S302: Receive echo signals corresponding to two groups of frequency-hopping linear frequency modulation signals, and mix each group of frequency-hopping linear frequency modulation signals with its corresponding echo signal to obtain two groups of intermediate frequency signals.

[0086] S303 , performing 2D-FFT on the two groups of intermediate frequency signals respectively to obtain a first range-Doppler map and a second range-Doppler map corresponding to the two groups of intermediate frequency signals respectively.

[0087] S304: Determine the detection targets in the first range-Doppler map and the second range-Doppler map, and initial first velocity information corresponding to the detection targets.

[0088] For example, a CFAR algorithm is used to identify a detection target in a first range-Doppler map and a second range-Doppler map; further, initial first velocity information corresponding to the detection target is extracted from the first range-Doppler map or the second range-Doppler map.

[0089] S305 : Acquire first initial phase information of the detection target in the first range-Doppler image and second initial phase information of the detection target in the second range-Doppler image.

[0090] That is, the first initial phase information of the detected target is extracted from the first range-Doppler map, and the second initial phase information of the detected target is extracted from the second range-Doppler map.

[0091] S306 : Determine the phase difference of the detection target at the corresponding position based on the first initial phase information and the second initial phase information.

[0092] S307: Obtain Doppler information of the detected target based on the phase difference.

[0093] S308: Determine corrected second velocity information based on the Doppler information and the signal parameters.

[0094] For example, according to the Doppler effect principle, based on the velocity and Doppler frequency shift f d The relationship between determines the speed, which satisfies the following formula:

[0095]

[0096] in, is the speed of light; is the speed, that is, the corrected second speed information.

[0097] S309 : Determine a distance to the detected target based on the first speed information, the second speed information, and signal parameters of the two sets of frequency-hopping linear frequency modulation signals.

[0098] For example, the distance R of the detected target satisfies the following formula:

[0099] R = 2 × Δv × T r ×f0 / Δf

[0100] Wherein, Δv is the speed difference, that is, the difference between the first speed information and the second speed information; T r is the transmission period of the linear frequency modulation signal, f0 is the starting frequency of the frequency hopping linear frequency modulation signal; Δf is the frequency hopping interval.

[0101] For example, Figure 4 This is a schematic diagram of the ranging results corresponding to the conventional linear frequency modulation radar in the related art. Figure 5 This is a schematic diagram of the ranging results corresponding to the frequency hopping linear frequency modulation radar provided by the exemplary embodiment of this application. Figure 4 and Figure 5 As shown in the figure, when the speed error is 0.1m / s, the ranging error of the frequency-hopping linear frequency modulation radar is 0.2m, while the ranging error of the conventional linear frequency modulation radar is 0.4m. In comparison, the ranging accuracy of the frequency-hopping linear frequency modulation radar is higher.

[0102] In summary, this application has at least the following advantages:

[0103] First, by interleaving the transmission of two sets of frequency-hopping linear frequency modulation signals within a single frame, each with different starting frequencies and a total frequency-hopping bandwidth greater than that of a single linear frequency modulation signal, the equivalent bandwidth is increased, significantly improving ranging resolution and thereby significantly enhancing ranging accuracy. This significantly reduces the risk of misjudgment or missed detection, thereby providing a more accurate perception basis for intelligent driving technology. Compared with conventional large-bandwidth linear frequency modulation signals, frequency-hopping linear frequency modulation signals have stronger anti-interference capabilities and can operate stably in complex electromagnetic environments. They can also reduce the amount of sampled data and data processing time, helping to improve data processing efficiency. In addition, by alternating the transmission of two sets of frequency-hopping linear frequency modulation signals within a single frame, data processing delay is effectively reduced and speed measurement accuracy is improved. Furthermore, speed information and signal parameters are combined to accurately determine the distance to the detected target, thereby achieving dual optimization of ranging and speed measurement accuracy.

[0104] Second, by performing 2D-FFT on the two sets of intermediate frequency signals to obtain range-Doppler maps, the position changes of the detected target within the signal acquisition interval are fully considered, which can more comprehensively analyze the relevant information of the detected target and effectively reduce the errors caused by single signal processing. Therefore, the initial first velocity information and the corrected second velocity information of the detected target can be more accurately determined, further reducing the speed measurement deviation and making the corrected second velocity information closer to the true value. This not only improves the accuracy of speed measurement, but also enhances the reliability of target detection and tracking.

[0105] Figure 6 A schematic diagram of a radar ranging device provided by an exemplary embodiment of the present application. Figure 6 As shown, the radar ranging device 60 includes a transmitting module 61, a receiving module 62, a first processing module 63 and a second processing module 64, wherein:

[0106] a transmitting module 61 configured to control the interleaved transmission of two sets of frequency-hopping linear frequency modulation signals within a single frame, wherein the two sets of frequency-hopping linear frequency modulation signals have different starting frequencies and the total bandwidth of a single set of frequency-hopping linear frequency modulation signals is greater than the bandwidth of a single linear frequency modulation signal;

[0107] The receiving module 62 is configured to receive the echo signals corresponding to the two sets of frequency-hopping linear frequency modulation signals, and mix each set of frequency-hopping linear frequency modulation signals with the echo signal corresponding thereto to obtain two sets of intermediate frequency signals;

[0108] A first processing module 63 is configured to determine initial first velocity information and corrected second velocity information corresponding to the detected target based on the two sets of intermediate frequency signals;

[0109] The second processing module 64 is configured to determine a distance to a detected target based on the first speed information, the second speed information, and signal parameters of the two sets of frequency-hopping linear frequency modulation signals.

[0110] In one possible implementation, the signal parameters include a transmission period of the linear frequency modulation signal, a starting frequency of the frequency-hopping linear frequency modulation signal, and a frequency-hopping interval. The second processing module 64 can be specifically used to: determine the difference between the first speed information and the second speed information to obtain a speed difference; determine the product of the speed difference, the transmission period of the linear frequency modulation signal, and the starting frequency of the frequency-hopping linear frequency modulation signal to obtain a target value; and determine the ratio of the target value to the frequency-hopping interval as the distance to the detected target.

[0111] In one possible implementation, the first processing module 63 can be specifically used to: perform 2D-FFT on the two groups of intermediate frequency signals respectively to obtain the first range-Doppler map and the second range-Doppler map corresponding to the two groups of intermediate frequency signals, respectively; determine the detection target in the first range-Doppler map and the second range-Doppler map, and the initial first velocity information corresponding to the detection target; obtain the first initial phase information of the detection target in the first range-Doppler map and the second initial phase information of the detection target in the second range-Doppler map; and determine the corrected second velocity information based on the first initial phase information and the second initial phase information.

[0112] In one possible implementation, the first processing module 63 can also be used to: determine the phase difference of the detection target at the corresponding position based on the first initial phase information and the second initial phase information; obtain the Doppler information of the detection target based on the phase difference; and determine the corrected second velocity information based on the Doppler information and signal parameters.

[0113] In a possible implementation, the first processing module 63 may also be configured to: use a CFAR algorithm to identify detection targets in the first range-Doppler map and the second range-Doppler map.

[0114] In one possible implementation, the first processing module 63 may also be used to: monitor the noise level and clutter characteristics of the current operating environment of the radar; evaluate the statistical characteristics of the noise and clutter based on the noise level and clutter characteristics; and adjust the detection threshold, number of protection units, and number of reference units of the CFAR algorithm based on the statistical characteristics.

[0115] In one possible implementation, a single linear frequency modulation signal satisfies the formula:

[0116]

[0117]

[0118] in, is the i-th linear frequency modulation signal in a single set of frequency hopping linear frequency modulation signals, t is the time variable; j is the imaginary unit; Δf is the frequency hopping step; μ is the frequency modulation slope of the linear frequency modulation signal; f0 is the starting frequency of the first linear frequency modulation signal transmitted; fh is the frequency difference between the starting frequency of the second linear frequency modulation signal and the starting frequency of the first linear frequency modulation signal; n = 0, 1, 2, …, N-1, where N is a positive integer greater than 1.

[0119] The radar ranging device provided in the embodiment of the present application can execute the technical solution shown in the above-mentioned radar ranging method embodiment. Its implementation principle and beneficial effects are similar and will not be repeated here.

[0120] It should be noted that it should be understood that the division of the various modules of the above device is merely a division of logical functions. In actual implementation, they can be fully or partially integrated into a physical entity, or they can be physically separated. Moreover, these modules can all be implemented in the form of software called by a processing element; or they can all be implemented in the form of hardware; or some modules can be implemented in the form of software called by a processing element, and some modules can be implemented in the form of hardware. For example, the second processing module can be a separately established processing element, or it can be integrated into a chip of the above device. In addition, it can also be stored in the memory of the above device in the form of program code, and called by a processing element of the above device to perform the functions of the above second processing module. The implementation of other modules is similar. In addition, these modules can all or partly be integrated together, or they can be implemented independently. The processing element here can be an integrated circuit with signal processing capabilities. During implementation, each step of the above method or each of the above modules can be completed by an integrated logic circuit of hardware in the processor element or by instructions in the form of software.

[0121] For example, the above modules may be one or more integrated circuits configured to implement the above methods, such as one or more application-specific integrated circuits (ASICs), one or more digital signal processors (DSPs), or one or more field programmable gate arrays (FPGAs). For another example, when a module is implemented by scheduling program code through a processing element, the processing element may be a general-purpose processor, such as a central processing unit (CPU) or other processor capable of calling program code. For another example, these modules may be integrated together and implemented in the form of a system-on-a-chip (SOC).

[0122] In the above embodiments, all or part of the embodiments can be implemented using software, hardware, firmware, or any combination thereof. When implemented using software, all or part of the embodiments can be implemented in the form of a computer program product. A computer program product includes one or more computer instructions. When the computer instructions are loaded and executed on a computer, all or part of the processes or functions according to the embodiments of the present application are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., coaxial cable, optical fiber, Digital Subscriber Line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium that can be accessed by a computer or a data storage device such as a server or data center that integrates one or more available media. Available media may be magnetic media (eg, floppy disks, hard disks, magnetic tapes), optical media (eg, Digital Video Discs (DVDs)), or semiconductor media (eg, solid state disks (SSDs)).

[0123] Figure 7 This is a schematic diagram of the structure of an electronic device provided by an exemplary embodiment of the present application. Figure 7 As shown, the electronic device 70 of this embodiment includes:

[0124] At least one processor 71; and a memory 72 communicatively connected to the at least one processor;

[0125] The memory 72 stores instructions that can be executed by the at least one processor 71 , and the instructions are executed by the at least one processor 71 to enable the electronic device to execute the method as described in any of the above embodiments.

[0126] Optionally, the memory 72 can be independent or integrated with the processor 71.

[0127] The memory 72 may include a high-speed random access memory (RAM), and may also include a non-volatile memory (non-volatile memory), such as at least one disk memory.

[0128] Processor 71 may be a central processing unit (CPU), an application-specific integrated circuit (ASIC), or one or more integrated circuits configured to implement the embodiments of the present application. Specifically, when implementing the radar ranging method described in the aforementioned method embodiment, the electronic device may be, for example, an electronic device with processing capabilities, such as a server.

[0129] Optionally, the electronic device may further include a communication interface 73. In a specific implementation, if the communication interface 73, memory 72, and processor 71 are implemented independently, the communication interface 73, memory 72, and processor 71 may be interconnected via a bus and communicate with each other. The bus may be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus, or an Extended Industry Standard Architecture (EISA) bus. Buses can be categorized as address buses, data buses, control buses, and so on, but this does not necessarily mean that there is only one bus or only one type of bus.

[0130] Optionally, in a specific implementation, if the communication interface 73, the memory 72 and the processor 71 are integrated on a chip, the communication interface 73, the memory 72 and the processor 71 can complete communication through an internal interface.

[0131] The implementation principle and technical effects of the electronic device provided in this embodiment can be found in the aforementioned embodiments and will not be described in detail here.

[0132] An embodiment of the present application also provides a computer-readable storage medium, which stores computer execution instructions. When the computer execution instructions are executed, they are used to implement the method steps in the above method embodiment. The specific implementation method and technical effects are similar and will not be repeated here.

[0133] The computer-readable storage medium described above can be implemented by any type of volatile or non-volatile storage device, or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic storage, flash memory, magnetic disk, or optical disk. The computer-readable storage medium can be any available medium that can be accessed by a general-purpose or special-purpose computer.

[0134] An exemplary readable storage medium is coupled to the processor, enabling the processor to read information from and write information to the readable storage medium. Alternatively, the readable storage medium may be an integral part of the processor. The processor and readable storage medium may be located in an application-specific integrated circuit. Alternatively, the processor and readable storage medium may be present as discrete components in the radar ranging device.

[0135] An embodiment of the present application also provides a computer program product, including a computer program. When the computer program is executed, the method steps in the above method embodiment are implemented. The specific implementation method and technical effects are similar and will not be repeated here.

[0136] Those skilled in the art will appreciate that all or part of the steps in the above-described method embodiments can be implemented using hardware associated with program instructions. The aforementioned program can be stored in a computer-readable storage medium. When executed, the program performs the steps of the above-described method embodiments. The aforementioned storage medium includes various media capable of storing program code, such as ROM, RAM, magnetic disks, or optical disks.

[0137] Finally, it should be noted that those skilled in the art will readily identify other embodiments of the present invention after considering the specification and practicing the invention disclosed herein. The present invention is intended to cover any variations, uses, or adaptations of the present invention that follow the general principles of the present invention and include common knowledge or customary techniques in the art not disclosed herein. The present invention is not limited to the precise structure described above and illustrated in the accompanying drawings, and various modifications and variations may be made without departing from the scope thereof. The scope of the present invention is limited solely by the appended claims.

Claims

1. A radar ranging method, characterized in that: include: Controlling the interleaved transmission of two sets of frequency hopping linear frequency modulation signals within a single frame, wherein the two sets of frequency hopping linear frequency modulation signals have different starting frequencies, and the total bandwidth of a single set of frequency hopping signals is greater than the bandwidth of a single linear frequency modulation signal; receiving echo signals corresponding to the two groups of frequency-hopping linear frequency modulation signals, and mixing each group of frequency-hopping linear frequency modulation signals with its corresponding echo signal to obtain two groups of intermediate frequency signals; Determining initial first speed information and corrected second speed information corresponding to the detected target based on the two sets of intermediate frequency signals; The distance of the detected target is determined based on the first speed information, the second speed information, and signal parameters of the two groups of frequency-hopping linear frequency modulation signals.

2. The radar ranging method according to claim 1, wherein: The signal parameters include a transmission period of a linear frequency modulation signal, a starting frequency of a frequency-hopping linear frequency modulation signal, and a frequency-hopping interval. The determining the distance of the detected target based on the first speed information, the second speed information, and the signal parameters of the two sets of frequency-hopping linear frequency modulation signals includes: determining a difference between the first speed information and the second speed information to obtain a speed difference; determining a product of the speed difference, a transmission period of the linear frequency modulation signal, and a starting frequency of the frequency-hopping linear frequency modulation signal to obtain a target value; The ratio of the target value to the frequency hopping interval is determined as the distance of the detected target.

3. The radar ranging method according to claim 1 or 2, characterized in that: The determining, based on the two sets of intermediate frequency signals, initial first speed information and corrected second speed information corresponding to the detected target includes: Performing a two-dimensional fast Fourier transform on the two groups of intermediate frequency signals to obtain a first range-Doppler map and a second range-Doppler map corresponding to the two groups of intermediate frequency signals respectively; Determining a detection target in the first range-Doppler map and the second range-Doppler map, and initial first velocity information corresponding to the detection target; Acquire first initial phase information of the detected target in the first range-Doppler image and second initial phase information of the detected target in the second range-Doppler image; Based on the first initial phase information and the second initial phase information, corrected second speed information is determined.

4. The radar ranging method according to claim 3, characterized in that: The determining, based on the first initial phase information and the second initial phase information, corrected second speed information includes: determining a phase difference of the detection target at a corresponding position based on the first initial phase information and the second initial phase information; Obtaining Doppler information of the detected target based on the phase difference; Based on the Doppler information and the signal parameter, corrected second velocity information is determined.

5. The radar ranging method according to claim 4, characterized in that: Determining the detection target in the first range-Doppler map and the second range-Doppler map includes: A constant false alarm rate algorithm is used to identify detection targets in the first range-Doppler map and the second range-Doppler map.

6. The radar ranging method according to claim 5, characterized in that: Also includes: monitoring noise levels and clutter characteristics of the radar's current operating environment; evaluating statistical characteristics of noise and clutter based on the noise level and clutter characteristics; Based on the statistical characteristics, the detection threshold, the number of protection units, and the number of reference units of the constant false alarm rate algorithm are adjusted.

7. The radar ranging method according to claim 1 or 2, characterized in that: The single linear frequency modulation signal satisfies the formula: in, is the i-th linear frequency modulation signal in a single set of frequency hopping linear frequency modulation signals, t is the time variable; j is the imaginary unit; Δf is the frequency hopping step; μ is the frequency modulation slope of the linear frequency modulation signal; f0 is the starting frequency of the first linear frequency modulation signal transmitted; f h is the frequency difference between the starting frequency of the second linear frequency modulation signal and the starting frequency of the first linear frequency modulation signal; n = 0, 1, 2, …, N-1, where N is a positive integer greater than 1.

8. A radar ranging device, characterized in that: include: A transmitting module, configured to control the interleaved transmission of two sets of frequency-hopping linear frequency modulation signals within a single frame, wherein the two sets of frequency-hopping linear frequency modulation signals have different starting frequencies and the total bandwidth of a single set of frequency-hopping linear frequency modulation signals is greater than the bandwidth of a single linear frequency modulation signal; a receiving module, configured to receive the echo signals corresponding to the two groups of frequency-hopping linear frequency modulation signals, and perform mixing processing on each group of frequency-hopping linear frequency modulation signals and its corresponding echo signal to obtain two groups of intermediate frequency signals; A first processing module is configured to determine initial first speed information and corrected second speed information corresponding to the detected target based on the two sets of intermediate frequency signals; The second processing module is configured to determine the distance of the detected target based on the first speed information, the second speed information, and signal parameters of the two groups of frequency-hopping linear frequency modulation signals.

9. An electronic device, characterized in that: include: a processor, and a memory communicatively connected to the processor; The memory is used to store computer-executable instructions; The processor is configured to execute the computer-executable instruction to implement the radar ranging method according to any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that The computer-readable storage medium stores computer-executable instructions, which are used to implement the radar ranging method according to any one of claims 1 to 7 when executed by a processor.

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