False target identification method and device, computer equipment and storage medium
By adjusting the phase of the radar transmit signal and analyzing the changes in echo energy, the problem that the vehicle-mounted millimeter-wave radar is difficult to distinguish between real and false targets is solved, and the detection accuracy and vehicle safety are improved.
Patent Information
- Application Number
- CN202411498021.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-25
- Publication Date
- 2025-02-14
AI Technical Summary
When millimeter-wave radar detects targets in the on-board field, it is difficult to distinguish between real and false targets, resulting in the false triggering of the automatic emergency braking system, affecting the safety of the vehicle and driving experience.
By acquiring the position information of the target to be identified, adjusting the phase of the transmitted signal at the second time, and calculating the echo energy change information based on the echo signals at the first and second time, and determining whether the target to be identified is a false target.
It improves detection accuracy, reduces false alarms of false targets, and enhances the vehicle's driving safety and the driver's experience.
Smart Images
Figure CN119439076A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the field of radar detection technology, and in particular to a false target recognition method, device, computer equipment and storage medium. Background Art
[0002] In the automotive field, millimeter-wave radar helps vehicles accurately detect targets on the surrounding roads and sense and avoid obstacles on the driving path. However, in actual operation, the detection of millimeter-wave radar may be interfered with, and real targets and false targets may coexist in the detection results and be difficult to distinguish. The detection of false targets may cause the automatic emergency braking system to be falsely triggered, which will reduce the safety of vehicle driving and the driver's experience.
[0003] Therefore, the current radar detection field still has the problem of low detection accuracy. Summary of the invention
[0004] Based on this, it is necessary to provide a false target identification method, device, computer equipment and storage medium that can improve detection accuracy in response to the above technical problems.
[0005] In a first aspect, the present application provides a false target identification method, the false target identification method comprising:
[0006] Acquire the position information of the target to be identified; the target to be identified is a new target appearing at the first moment; the position information includes the target angle;
[0007] Based on the position information of the target to be identified, adjusting the phase of the transmitted signal at the second moment;
[0008] Calculating echo energy change information at the first moment and the second moment based on the echo signals at the first moment and the second moment;
[0009] Based on the echo energy change information, it is determined whether the target to be identified is a false target.
[0010] In some embodiments, the step of obtaining the location information of the target to be identified includes:
[0011] Obtain the echo signal at the first moment and the track information within a preset time range;
[0012] Determine at least one detection target based on the echo signal at the first moment;
[0013] Matching at least one detected target with the track information;
[0014] The detected target that fails to match is regarded as the new target appearing at the first moment.
[0015] In some embodiments, the position information further includes target distance and target speed; and adjusting the phase of the transmitted signal at the second moment based on the position information of the target to be identified includes:
[0016] Calculating an offset phase based on the position information of the target to be identified;
[0017] Based on the offset phase, the phase of the transmission signal at the second moment is adjusted.
[0018] In some embodiments, the echo energy change information includes a first normalized power distribution, a second normalized power distribution, and an energy change distribution; and the calculating the echo energy change information at the first moment and the second moment based on the echo signals at the first moment and the second moment includes:
[0019] Calculating a first normalized power distribution at the first moment based on the echo signal at the first moment;
[0020] Calculating a second normalized power distribution at the second moment based on the echo signal at the second moment;
[0021] Based on the first normalized power distribution and the second normalized power distribution, energy change distributions at the first moment and the second moment are determined.
[0022] In some embodiments, the first normalized power distribution and the second normalized power distribution respectively include normalized powers at multiple azimuth angles, and determining the energy change distribution at the first moment and the second moment based on the first normalized power distribution and the second normalized power distribution includes:
[0023] Determine a normalized power change value at each azimuth based on normalized power values of multiple azimuths in the first normalized power distribution and the second normalized power distribution;
[0024] Based on the normalized power change values at multiple azimuth angles, an energy change distribution is determined.
[0025] In some embodiments, judging whether the target to be identified is a false target based on the echo energy change information includes:
[0026] Determine a normalized power change value corresponding to the azimuth of the target to be identified based on the energy change distribution and the target angle of the target to be identified;
[0027] If the normalized power change value is greater than a preset change threshold, the target to be identified is a real target; if the normalized power change value is less than or equal to the preset change threshold, the target to be identified is a false target.
[0028] In some embodiments, if the normalized power change value is greater than a preset change threshold, the target to be identified is a real target before comprising:
[0029] Determine a main-to-sidelobe ratio threshold value based on the main-to-sidelobe ratio in the first normalized power distribution and / or the second normalized power distribution;
[0030] The main-to-sidelobe ratio threshold value is used as a preset change threshold value.
[0031] In a second aspect, the present application provides a false target identification device, the device comprising:
[0032] An acquisition module, used to acquire the position information of a target to be identified; the target to be identified is a new target that appears at the first moment;
[0033] An adjustment module, configured to adjust the phase of the transmission signal at a second moment based on the position information of the target to be identified;
[0034] A calculation module, used to calculate echo energy change information at the first moment and the second moment based on the echo signals at the first moment and the second moment;
[0035] A judgment module is used to judge whether the target to be identified is a false target based on the echo energy change information.
[0036] In a third aspect, the present application provides a computer device, including a memory and a processor, wherein the memory stores a computer program, and the processor implements the above-mentioned method when executing the computer program.
[0037] In a fourth aspect, the present application provides a computer-readable storage medium having a computer program stored thereon, wherein the computer program implements the method described above when executed by a processor.
[0038] The above-mentioned false target identification method, device, computer equipment and storage medium adjust the phase of the transmitted signal at the second moment based on the position information of the target to be identified; calculate the echo energy change information at the first moment and the second moment based on the echo signals at the first moment and the second moment; based on the echo energy change information, determine whether the target to be identified is a false target, and adjust the phase of the transmitted signal at the second moment, and then detect it according to the difference between the echo signals of the previous and next frames with different phases, thereby avoiding interference from multipath effects or noise, etc., and can detect false targets without changing the hardware structure of the radar or increasing the hardware cost, so that the interference of false targets can be eliminated in a short time, and the effect of improving the detection accuracy can be achieved. Furthermore, by eliminating the interference of false targets, it is possible to avoid the influence of false targets on the driving process, thereby improving the driving safety and the driver's experience. BRIEF DESCRIPTION OF THE DRAWINGS
[0039] Figure 1 A diagram showing an application environment of a false target identification method in one embodiment;
[0040] Figure 2 1 is a flow chart of a false target identification method in one embodiment;
[0041] Figure 3 is an azimuthal equivalent aperture distribution diagram in one embodiment;
[0042] Figure 4 is a flow chart of a false target identification method in another embodiment;
[0043] Figure 5 The figure is a normalized power distribution diagram of the transmission and reception synthesis in one embodiment;
[0044] Figure 6 is an azimuthal equivalent aperture distribution diagram in another embodiment;
[0045] Figure 7 A normalized power distribution diagram of the transmission and reception synthesis in another embodiment;
[0046] Figure 8 Schematic diagram of waveforms of a current frame and a next frame in one embodiment;
[0047] Fig. 9 A normalized power distribution diagram of the transmission and reception synthesis in another embodiment;
[0048] Fig.10 is an energy change distribution diagram in one embodiment;
[0049] Fig.11 is a structural block diagram of a false target identification device in one embodiment;
[0050] Fig.12 FIG. 4 is a diagram showing the internal structure of a computer device in one embodiment. DETAILED DESCRIPTION
[0051] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.
[0052] The false target identification method provided in the embodiment of the present application can be applied to Figure 1 In the application environment shown. Among them, the terminal 102 communicates with the server 104 through the network. The data storage system can store the data that the server 104 needs to process. The data storage system can be integrated on the server 104, or it can be placed on the cloud or other network servers. The terminal 102 obtains the location information of the target to be identified; the target to be identified is a new target that appears at the first moment; the location information includes the target angle; based on the location information of the target to be identified, the phase of the transmitted signal at the second moment is adjusted; based on the echo signal at the first moment and the second moment, the echo energy change information at the first moment and the second moment is calculated; based on the echo energy change information, it is determined whether the target to be identified is a false target. Among them, the terminal 102 can be, but is not limited to, various personal computers, laptops, smart phones, tablet computers, Internet of Things devices and portable wearable devices, and the Internet of Things devices can be smart speakers, smart TVs, smart air conditioners, smart car-mounted devices, etc. Portable wearable devices can be smart watches, smart bracelets, head-mounted devices, etc. The server 104 can be implemented with an independent server or a server cluster consisting of multiple servers.
[0053] In one embodiment, Figure 2 As shown, a false target recognition method is provided, and the method is applied to Figure 1 The terminal 102 in the example is used as an example to illustrate, and the following steps are included:
[0054] Step S100, obtaining the location information of the target to be identified.
[0055] The target to be identified is a new target that appears at the first moment. The first moment may be the current frame or the moment when the new target is detected. Exemplarily, during the radar detection process, sampling may be performed frame by frame, and target identification may be performed based on radar data sampled in each frame to form target track information. When a new target appears in the target identification result, the current frame may be used as the first moment, and the false target identification process may be enabled.
[0056] It can be understood that the first moment and the second moment can be sampling moments, and the transmission signal and the echo signal within the sampling unit time defined by the sampling frequency can both be regarded as data obtained by sampling at one moment.
[0057] The position information is used to characterize the position of the target to be identified relative to the vehicle. For example, the position information may include the target angle, through which the position of the target to be identified relative to the vehicle can be determined. Furthermore, the position information may also include other information characterizing the target to be identified, for example, it may also include plane or spatial position information such as distance, altitude, longitude and latitude, and may also include motion position information such as speed, acceleration, and motion direction.
[0058] Step S200: adjusting the phase of the transmitted signal at the second moment based on the position information of the target to be identified.
[0059] The transmission signal at the second moment may be generated in advance, and then the phase of the transmission signal may be adjusted based on the position information of the target to be identified. Furthermore, the transmission signal at the second moment generated in advance may be the same as the transmission signal at the first moment, thereby eliminating the difference caused by the difference of the transmission signals at the two moments themselves.
[0060] The phase adjustment is performed based on the position information of the target to be identified, and the phase can be adjusted according to the target angle of the target to be identified. Through the phase adjustment, the signal strength in the direction of the target to be identified can be enhanced, so as to better distinguish the real target from the false target in the future.
[0061] Step S300: Calculate echo energy change information at the first moment and the second moment based on the echo signals at the first moment and the second moment.
[0062] The echo signal is the signal reflected from the radar's transmitted signal. In the actual detection process, the echo signal includes not only the signal reflected from the real target and the target to be identified, but also the signal reflected after multiple reflections or scattering. In this embodiment, in order to solve the problem that the echo signal at the first moment detects a false target due to multipath effect or noise interference, the echo signal at the second moment is obtained by adjusting the phase of the transmitted signal at the second moment, and the echo energy change information at the first moment and the second moment is obtained, so that the possible multipath effect and noise interference under the transmitted signal at the first moment can be eliminated.
[0063] The echo energy change information is obtained by comparing the energy difference between the echo signals at the first moment and the second moment, thereby reflecting the change of the target characteristics. Further, the echo signals at the first moment and the second moment can be analyzed respectively to determine the echo energy magnitudes at different orientations, and then the echo energy magnitudes at multiple orientations at the first moment and the second moment can be analyzed to obtain the echo energy change information.
[0064] Step S400: judging whether the target to be identified is a false target based on the echo energy change information.
[0065] Among them, based on the echo energy change information, judging whether the target to be identified is a false target can be done by judging, based on the target angle of the target to be identified, whether the echo energy change in the area or orientation corresponding to the target to be identified in the echo energy change information conforms to the echo energy change law of the real target.
[0066] Exemplarily, when in the echo energy change information, the echo energy of the area or direction corresponding to the target to be identified at the second moment is significantly higher than the echo energy at the first moment, it can be considered that there is a real target in the area or direction corresponding to the target to be identified.
[0067] The false target identification method of this embodiment can be applied to existing millimeter-wave radar equipment, that is, without changing the existing millimeter-wave radar hardware and avoiding increasing the hardware cost, by adjusting the phase of the transmitted signal and analyzing the echo energy change, false target identification and judgment can be achieved, thereby improving the detection accuracy of the millimeter-wave radar.
[0068] The present embodiment provides a false target identification method, which adjusts the phase of the transmitted signal at a second moment based on the position information of the target to be identified; calculates the echo energy change information at the first moment and the second moment based on the echo signals at the first moment and the second moment; and determines whether the target to be identified is a false target based on the echo energy change information, and adjusts the phase of the transmitted signal at the second moment, and then can detect according to the difference between the echo signals of the previous and next frames with different phases, thereby avoiding interference from multipath effects or noise, and realizing detection of false targets, thereby eliminating interference from false targets in a short time, and achieving the effect of improving detection accuracy. Furthermore, by eliminating interference from false targets, it is possible to avoid the influence of false targets on the driving process, thereby improving driving safety and driver experience.
[0069] In some embodiments, the step of obtaining the location information of the target to be identified includes:
[0070] Obtain the echo signal at the first moment and the track information within a preset time range;
[0071] Determine at least one detection target based on the echo signal at the first moment;
[0072] Matching at least one detected target with the track information;
[0073] The detected target that fails to match is regarded as the new target appearing at the first moment.
[0074] The echo signal at the first moment may be an echo signal acquired at the first moment, and the echo signal may be obtained by reflecting or refracting the transmitted signal.
[0075] The track information within the preset time range may be the motion trajectory data of one or more targets recorded by the radar system within the preset time range. The track information may be obtained based on target detection and target matching at multiple moments.
[0076] Based on the echo signal at the first moment, at least one detection target is determined, and the echo signal may be analyzed to obtain one or more possible target objects, wherein the relevant information of the analyzed target objects may include relative angles, relative distances, and the like.
[0077] Matching at least one detected target with the track information may be performed by matching the motion trajectory of each known target in the track information based on information such as the relative angle and relative distance of the detected target. In a specific embodiment, matching the motion trajectory of each known target in the track information may be performed by predicting the position at the next moment based on the motion trajectory of each known target. If the detected target matches the predicted position of the known target, the detected target may be considered to be a known target. In a specific embodiment, matching the motion trajectory of each known target in the track information may be performed by sequentially determining the motion trajectory of the known target that best matches each detected target, and determining whether there is an anomaly in the motion trajectory combined with the detected target. If there is no anomaly, the detected target may be considered to be successfully matched with the known target.
[0078] After matching at least one detected target with the track information, if there is a detected target that fails to match, the detected target is regarded as a new target appearing at the first moment.
[0079] A false target identification method provided in this embodiment matches at least one detected target with the track information; and regards the detected target that fails to match as a new target that appears at the first moment. This method effectively identifies the new target that appears in the echo signal by comparing the historical track information file, thereby achieving the effect of improving the system response speed and safety.
[0080] In some embodiments, adjusting the phase of the transmitted signal at the second moment based on the position information of the target to be identified includes:
[0081] Calculating an offset phase based on the position information of the target to be identified;
[0082] Based on the offset phase, the phase of the transmission signal at the second moment is adjusted.
[0083] The offset phase is calculated based on the position information of the target to be identified, and the offset phase can be obtained according to a preset mapping relationship based on the target angle of the target to be identified, or according to a preset algorithm.
[0084] Based on the offset phase, the phase of the transmission signal at the second moment is adjusted, and the offset phase may be superimposed on the phase of the transmission signal to obtain an adjusted transmission signal.
[0085] Furthermore, the position information also includes the target distance and the target speed. Exemplarily, the offset phase is calculated based on the position information of the target to be identified, and the position of the target to be identified at the next moment can be predicted based on one or more of the target angle, target distance and target speed, and the offset phase is calculated based on the predicted position, thereby adjusting the phase of the transmitted signal at the second moment. Furthermore, when calculating the offset phase, the calculation can also be combined with the signal propagation time, Doppler frequency shift, etc.
[0086] A false target identification method provided in this embodiment calculates an offset phase based on the position information of the target to be identified; based on the offset phase, the phase of the transmitted signal at the second moment is adjusted, so that more accurate adjustment of the transmitted signal phase can be achieved, thereby more accurately identifying and distinguishing targets, reducing false alarms of false targets, and achieving the effect of improving the safety and reliability of the autonomous driving or assisted driving system.
[0087] In some embodiments, the echo energy change information includes a first normalized power distribution, a second normalized power distribution, and an energy change distribution; and the calculating the echo energy change information at the first moment and the second moment based on the echo signals at the first moment and the second moment includes:
[0088] Calculating a first normalized power distribution at the first moment based on the echo signal at the first moment;
[0089] Calculating a second normalized power distribution at the second moment based on the echo signal at the second moment;
[0090] Based on the first normalized power distribution and the second normalized power distribution, energy change distributions at the first moment and the second moment are determined.
[0091] The calculation of the normalized power distribution may be to normalize the power value of the echo signal to obtain the normalized power distribution. The normalization process may eliminate the absolute value difference of the signal strength, making the signals at different time points more comparable, thereby more accurately analyzing the change trend of the signal.
[0092] The first normalized power distribution at the first moment and the second normalized power distribution at the second moment are calculated, so that the normalized power distributions of the echo signals at the two moments can be obtained.
[0093] Based on the first normalized power distribution and the second normalized power distribution, the energy change distribution at the first moment and the second moment is determined, and the energy change distribution at the two moments is obtained according to the power difference between the first normalized power distribution and the second normalized power distribution.
[0094] A false target identification method provided in this embodiment can more accurately determine the energy distribution of the echo signal in the target area to be identified through normalization processing and calculation of energy change distribution, thereby more accurately determining whether the target to be identified is a false target, thereby achieving the effect of improving detection accuracy.
[0095] In some embodiments, determining the energy change distribution at the first moment and the second moment based on the first normalized power distribution and the second normalized power distribution includes:
[0096] Determine a normalized power change value at each azimuth based on normalized power values of multiple azimuths in the first normalized power distribution and the second normalized power distribution;
[0097] Based on the normalized power change values at multiple azimuth angles, an energy change distribution is determined.
[0098] The first normalized power distribution and the second normalized power distribution respectively include normalized powers at multiple azimuth angles, that is, each azimuth angle corresponds to a normalized power value.
[0099] The normalized power change value is determined based on the normalized power values of the first normalized power distribution and the second normalized power distribution at multiple azimuths. The normalized power change value can be obtained by subtracting the normalized power values in the first normalized power distribution and the second normalized power distribution.
[0100] Thus, a normalized power change value at each azimuth angle can be obtained, and thus energy change distribution can be obtained based on the normalized power change values at multiple azimuth angles.
[0101] It can be understood that the energy change distribution reflects the signal change after the phase adjustment between the first moment and the second moment. At the second moment, due to the phase adjustment, if the target to be identified is a real target, the echo energy of the target to be identified at the second moment should theoretically be greatly improved compared to the first moment. Otherwise, it may be a false target.
[0102] A false target identification method provided in this embodiment obtains the normalized power change value at each azimuth angle through the normalized power distribution at two moments, and then determines the energy change distribution. It can realize the change analysis of the normalized power value at each azimuth angle, thereby improving the accuracy of target detection and more accurately determining whether the target to be identified is a false target, thereby achieving the effect of improving the detection accuracy.
[0103] In some embodiments, judging whether the target to be identified is a false target based on the echo energy change information includes:
[0104] Determine a normalized power change value corresponding to the azimuth of the target to be identified based on the energy change distribution and the target angle of the target to be identified;
[0105] If the normalized power change value is greater than a preset change threshold, the target to be identified is a real target; if the normalized power change value is less than or equal to the preset change threshold, the target to be identified is a false target.
[0106] Among them, based on the energy change distribution and the target angle of the target to be identified, the normalized power change value of the azimuth corresponding to the target to be identified is determined. The energy change distribution can be queried according to the target angle of the target to be identified to determine the azimuth that matches the target angle, so as to obtain the normalized power change value corresponding to the azimuth.
[0107] The preset change threshold is used to determine whether the normalized power change value of the target to be identified exceeds the change value that the real target should have. The preset change threshold can be set based on prior knowledge or a threshold value determined based on other parameters.
[0108] A false target identification method provided in this embodiment can effectively identify and distinguish real targets from false targets by determining the normalized power change value of the target to be identified according to the target angle of the target to be identified, and determining whether it is a real target by comparison, thereby achieving the effect of improving the detection accuracy.
[0109] In some embodiments, if the normalized power change value is greater than a preset change threshold, the target to be identified is a real target before comprising:
[0110] Determine a main-to-sidelobe ratio threshold value based on the main-to-sidelobe ratio in the first normalized power distribution and / or the second normalized power distribution;
[0111] The main-to-sidelobe ratio threshold value is used as a preset change threshold value.
[0112] The main-sidelobe ratio may be the power wallpaper of the main lobe and the side lobe of the radar antenna, the main lobe may be the beam with the highest power in the power distribution, and the side lobe may be the beam with the second highest power in the power distribution or the beam next to the main lobe. The main-sidelobe ratio may be the ratio of the main lobe power value to the side lobe power value.
[0113] Based on the main-to-sidelobe ratio in the first normalized power distribution and / or the second normalized power distribution, a main-to-sidelobe ratio threshold value is determined. The main-to-sidelobe ratio threshold value can be determined according to the main-to-sidelobe ratio of the first normalized power distribution or the second normalized power distribution, or the main-to-sidelobe ratio can be determined according to the highest and second highest power beams in the first normalized power distribution and the second normalized power distribution, and then the main-to-sidelobe ratio threshold value is determined.
[0114] The main-sidelobe ratio threshold value is determined according to the main-sidelobe ratio. The value of the main-sidelobe ratio can be used as the threshold value and then as the preset change threshold value, or a preset algorithm is mapped according to the value of the main-sidelobe ratio to obtain the main-sidelobe ratio threshold value corresponding to the main-sidelobe ratio as the preset change threshold value.
[0115] A false target identification method provided in this embodiment can more accurately reflect the intensity distribution of echo signals in different directions by using the main-sidelobe ratio threshold value as the preset change threshold, thereby more effectively distinguishing real targets from false targets, significantly reducing false alarms, and thus achieving the effect of improving the accuracy of target identification.
[0116] In order to more clearly illustrate the technical solution of the present application, the present application also provides a detailed embodiment.
[0117] In one embodiment, take four-way transmission and four-way reception, the most conventional uniform array as an example. Figure 3 The equivalent aperture distribution diagram in the azimuth direction is shown as follows: Figure 4 As shown, a false target identification method is provided, which is applied to a time division multiple access radar, and the method comprises:
[0118] When a new target appears in the field of view of the time division multiple access radar and the new target cannot be associated with the original track target, the frame where the new target appears is recorded as the current frame, that is, the first moment, and the new target is used as the target to be identified to determine whether it is a false target.
[0119] Get the distance, speed and angle of the target to be identified in the current frame.
[0120] In the radar array design, each transmitting or receiving equivalent aperture is one array element, and the input signal is X n (t), the spacing between different array elements is d n-1 , the total number of array elements is N. When the incoming direction of the electromagnetic wave is θ, the output signal Y of the nth array element is n (t) can be expressed as:
[0121]
[0122] Therefore, the output and weighting coefficient w(θ) of each array element can be represented by a vector:
[0123] X n (t)=[x1(t) x2(t)...x n (r)] T
[0124] w(θ)=[w1(θ) w2(θ)...w n (θ)] T
[0125] Y n (t) = w H (θ)X n (t)
[0126] Based on the output of each array element and the weighting coefficient w(θ), the output power P of the beamforming, that is, the power distribution of the echo signal, can be calculated:
[0127]
[0128] Furthermore, the output power P is normalized to obtain the normalized power P1, which can be expressed as:
[0129] P1=10log(P / P max )
[0130] Among them, P max is the maximum output power of beamforming. The normalized power is linearly related to the target echo energy intensity.
[0131] Based on the above processing, a normalized power distribution diagram of the transmission and reception synthesis of the current frame can be obtained.
[0132] In this embodiment, based on the time division multiple access waveform, when a new target that cannot be associated with the track information of the previous frames appears in the targets detected in the current frame, the distance R, speed V, and angle θ information of the target in the current frame can be used as a priori conditions to change the time division multiple access transmission waveform of the next frame, that is, adjust the phase of the transmission signal, and add an offset phase θ to the transmission signal of the next frame according to the direction of the target wave. Then, the normalized power distribution of the transmission and reception synthesis of the next frame changes, thereby changing the energy distribution of the synthesis directional pattern in space. Obtain the distance, speed, and angle of the next frame, and get Figure 5 The normalized power distribution diagram of the current frame and the next frame is shown, so as to judge whether the target echo energy conforms to the law. If it conforms, the target is a real target, if not, the target is a false target.
[0133] The normalized power distribution characterizes the echo energy at each azimuth angle in the frame. The combined normalized power distribution of transmission and reception includes the normalized power distribution of the current frame and the next frame, and thus characterizes the echo energy change at each azimuth angle in the previous and next frames.
[0134] Based on the offset phase θ of the transmission signal of the next frame, the normalized power distribution diagram of the transmit and receive synthesis of the next frame is translated by θ in space compared to the current frame, changing the energy distribution of the synthetic beam in space. The energy change distribution of the previous and next frames can be obtained by subtracting them.
[0135] Furthermore, to determine whether the target is a false target, the target information of the current frame and the next frame can be compared, and the echo energy change of the two frames before and after the target can be compared to see whether it conforms to the expected energy change law of the synthetic directional pattern of the previous and next frames. In this embodiment, the main-sidelobe ratio can be used as a threshold value to define whether the target to be identified conforms to the change law of the real target, or an additional threshold value can be set to define the standard of the change law. The main-sidelobe ratio of this embodiment can be the energy difference between the main lobe and the first sidelobe of the synthetic directional pattern.
[0136] First, the target information can be aligned from the target output lists of the previous and next frames. If there is a new target that is difficult to associate with the track information and needs to be judged whether it is a false target, the latter frame of the previous and next frames is used as the current frame, and the target is found in the target list of the next frame according to the distance and speed. If the increase in its echo energy in the next frame is greater than the threshold, it means that the change in the target echo energy is associated with the energy change of the current angle transmit and receive composite directional pattern, then it is a real target; conversely, if it is lower than the threshold, it may be a false target caused by multipath interference, interference from other sensors or noise interference.
[0137] It can be understood that the false target identification method of this embodiment can realize false target identification without changing the existing radar software and hardware architecture. Therefore, the false target identification method of this application does not limit the number of transmitting and receiving channels, nor does it limit their array layout.
[0138] For example, in a radar with three-way transmission and four-way reception and non-uniform sparse array, the equivalent aperture distribution in the azimuth direction is as follows: Figure 6 As shown, the normalized power distribution can also be synthesized based on the transmission and reception of the current frame and the next frame, as shown in Figure 7 As shown, it is possible to determine whether the target's echo energy change conforms to a regular pattern, thereby determining whether the target is a false target.
[0139] For millimeter-wave radar, the false target identification method based on time-division multiple access waveform proposed in this embodiment can judge whether the target is a real target or a false target by changing the phase between time-division multiple access waveform frames and changing the energy distribution of the synthetic beam in space without changing the existing millimeter-wave radar software and hardware architecture, thereby improving the effectiveness and authenticity of millimeter-wave radar detection and reducing misjudgments and false alarms of millimeter-wave radar.
[0140] In a specific embodiment, taking the target angle θ=30° of the new target as an example, when a new target that cannot be associated with the track information appears at the first moment, the first moment is taken as the current frame, and the next frame is taken as the second moment. According to the distance R, speed V and angle θ information of the new target in the current frame, an offset phase θ is added to the time division multiple access waveform at the second moment. The waveform diagram of the current frame and the next frame based on the time division multiple access waveform is shown as follows: Figure 8 shown.
[0141] The normalized power distribution of the transmission and reception of the current frame and the next frame is as follows: Fig. 9 As shown. By adding a phase θ to the next frame of TDMA transmission waveform, the distribution of the synthetic beam in space is changed. Subtraction can obtain the energy change distribution as shown in Fig.10 shown.
[0142] In this case, assuming that two targets are detected in the current frame within the radar field of view, including a real target at an angle of 10° and a new target at an angle of 30° that cannot be associated with the track, the echo energy change of the target between the current frame and the next frame should satisfy the following table.
[0143]
[0144] Among them, the main sidelobe ratio of the synthetic pattern is 10dB, so 10dB can be used as the threshold value, or the threshold value can be appropriately lowered. If the echo energy change of the new target between the current frame and the next frame conforms to the law of significant increase, that is, the amplitude increase value exceeds the threshold value, then it can be considered that the target is a real target in the 30° direction; if it does not meet this rule and is not related to the synthetic beam energy distribution in this direction, then the new target may be a false target caused by multipath interference, interference from other sensors or noise interference.
[0145] It is understandable that the false target identification method based on the time division multiple access waveform provided in this embodiment does not affect the detection of the real target originally located at 10°, but the echo energy in the next frame is slightly different. When it is determined that the new target that cannot be associated with the track is a false target, it is deleted from the target output list, thereby avoiding the false detection and false alarm phenomenon of the millimeter wave radar.
[0146] This embodiment provides a false target identification method. When a target that cannot be associated with the track targets of the previous frames appears within the radar field of view, the phase of the transmission signal based on the time division multiple access waveform is adjusted to change the energy distribution of the synthetic directional pattern in space. Through the difference in the energy of the target echoes of the previous and next two frames, the false target and the real target can be distinguished. Without increasing the hardware cost of the existing millimeter wave radar, the accuracy of millimeter wave radar target detection can be improved by adjusting the time division multiple access waveform, thereby achieving the effect of improving the safety and accuracy of the vehicle during driving.
[0147] It should be understood that, although the various steps in the flowcharts involved in the above-mentioned embodiments are displayed in sequence according to the indication of the arrows, these steps are not necessarily executed in sequence according to the order indicated by the arrows. Unless there is a clear explanation in this article, the execution of these steps does not have a strict order restriction, and these steps can be executed in other orders. Moreover, at least a part of the steps in the flowcharts involved in the above-mentioned embodiments can include multiple steps or multiple stages, and these steps or stages are not necessarily executed at the same time, but can be executed at different times, and the execution order of these steps or stages is not necessarily to be carried out in sequence, but can be executed in turn or alternately with other steps or at least a part of the steps or stages in other steps.
[0148] Based on the same inventive concept, the embodiment of the present application also provides a false target identification device for implementing the false target identification method involved above. The implementation scheme for solving the problem provided by the device is similar to the implementation scheme recorded in the above method, so the specific limitations in one or more false target identification device embodiments provided below can refer to the limitations of the false target identification method above, and will not be repeated here.
[0149] In one embodiment, Fig.11 As shown, a false target identification device is provided, comprising: an acquisition module 100, an adjustment module 200, a calculation module 300 and a judgment module 400, wherein:
[0150] The acquisition module 100 is used to acquire the position information of the target to be identified; the target to be identified is a new target that appears at the first moment; the position information includes the target angle;
[0151] An adjustment module 200, configured to adjust the phase of the transmission signal at a second moment based on the position information of the target to be identified;
[0152] A calculation module 300, configured to calculate echo energy change information at the first moment and the second moment based on the echo signals at the first moment and the second moment;
[0153] The judgment module 400 is used to judge whether the target to be identified is a false target based on the echo energy change information.
[0154] In some embodiments, the acquisition module 100 is further used for:
[0155] Obtain the echo signal at the first moment and the track information within a preset time range;
[0156] Determine at least one detection target based on the echo signal at the first moment;
[0157] Matching at least one detected target with the track information;
[0158] The detected target that fails to match is regarded as the new target appearing at the first moment.
[0159] In some embodiments, the position information further includes target distance and target speed; the adjustment module 200 is further used to:
[0160] Calculating an offset phase based on the position information of the target to be identified;
[0161] Based on the offset phase, the phase of the transmission signal at the second moment is adjusted.
[0162] In some embodiments, the echo energy variation information includes a first normalized power distribution, a second normalized power distribution and an energy variation distribution; the calculation module 300 is further used for:
[0163] Calculating a first normalized power distribution at the first moment based on the echo signal at the first moment;
[0164] Calculating a second normalized power distribution at the second moment based on the echo signal at the second moment;
[0165] Based on the first normalized power distribution and the second normalized power distribution, energy change distributions at the first moment and the second moment are determined.
[0166] In some embodiments, the first normalized power distribution and the second normalized power distribution respectively include normalized powers at multiple azimuth angles, and the calculation module 300 is further configured to:
[0167] Determine a normalized power change value at each azimuth based on normalized power values of multiple azimuths in the first normalized power distribution and the second normalized power distribution;
[0168] Based on the normalized power change values at multiple azimuth angles, an energy change distribution is determined.
[0169] In some embodiments, the determination module 400 is further configured to:
[0170] Determine a normalized power change value corresponding to the azimuth of the target to be identified based on the energy change distribution and the target angle of the target to be identified;
[0171] If the normalized power change value is greater than a preset change threshold, the target to be identified is a real target; if the normalized power change value is less than or equal to the preset change threshold, the target to be identified is a false target.
[0172] In some embodiments, the determination module 400 is further configured to:
[0173] Determine a main-to-sidelobe ratio threshold value based on the main-to-sidelobe ratio in the first normalized power distribution and / or the second normalized power distribution;
[0174] The main-to-sidelobe ratio threshold value is used as a preset change threshold value.
[0175] Each module in the above-mentioned false target identification device can be implemented in whole or in part by software, hardware or a combination thereof. Each module can be embedded in or independent of a processor in a computer device in the form of hardware, or can be stored in a memory in a computer device in the form of software, so that the processor can call and execute operations corresponding to each module.
[0176] In one embodiment, a computer device is provided. The computer device may be a terminal, and its internal structure diagram may be as follows: Fig.12As shown. The computer device includes a processor, a memory, a communication interface, a display screen and an input device connected through a system bus. Among them, the processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The communication interface of the computer device is used to communicate with an external terminal in a wired or wireless manner, and the wireless manner can be achieved through WIFI, a mobile cellular network, NFC (near field communication) or other technologies. When the computer program is executed by the processor, a false target identification method is implemented. The display screen of the computer device can be a liquid crystal display screen or an electronic ink display screen, and the input device of the computer device can be a touch layer covered on the display screen, or a key, trackball or touchpad set on the computer device shell, or an external keyboard, touchpad or mouse, etc.
[0177] Those skilled in the art will understand that Fig.12 The structure shown in the figure is only a block diagram of a part of the structure related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. The specific computer device may include more or fewer components than those shown in the figure, or combine certain components, or have a different arrangement of components.
[0178] In one embodiment, a computer device is provided, including a memory and a processor, wherein a computer program is stored in the memory, and when the processor executes the computer program, the false target identification method of any of the above embodiments is implemented:
[0179] Acquire the position information of the target to be identified; the target to be identified is a new target appearing at the first moment; the position information includes the target angle;
[0180] Based on the position information of the target to be identified, adjusting the phase of the transmitted signal at the second moment;
[0181] Calculating echo energy change information at the first moment and the second moment based on the echo signals at the first moment and the second moment;
[0182] Based on the echo energy change information, it is determined whether the target to be identified is a false target.
[0183] In one embodiment, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the false target identification method of any of the above embodiments is implemented:
[0184] Acquire the position information of the target to be identified; the target to be identified is a new target appearing at the first moment; the position information includes the target angle;
[0185] Based on the position information of the target to be identified, adjusting the phase of the transmitted signal at the second moment;
[0186] Calculating echo energy change information at the first moment and the second moment based on the echo signals at the first moment and the second moment;
[0187] Based on the echo energy change information, it is determined whether the target to be identified is a false target.
[0188] 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.
[0189] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to the memory, database or other medium used in the embodiments provided in the present application can include at least one of non-volatile 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), magnetoresistive random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. As an illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM). The database involved in each embodiment provided in this application may include at least one of a relational database and a non-relational database. Non-relational databases may include distributed databases based on blockchains, etc., but are not limited to this. The processor involved in each embodiment provided in this application may be a general-purpose processor, a central processing unit, a graphics processor, a digital signal processor, a programmable logic device, a data processing logic device based on quantum computing, etc., but are not limited to this.
[0190] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.
[0191] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be construed as limiting the scope of the present application. It should be noted that, for a person of ordinary skill in the art, several modifications and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.
Claims
1. A false target identification method, characterized in that: The false target identification method comprises: Acquire the position information of the target to be identified; the target to be identified is a new target appearing at the first moment; the position information includes the target angle; Based on the position information of the target to be identified, adjusting the phase of the transmitted signal at the second moment; Calculating echo energy change information at the first moment and the second moment based on the echo signals at the first moment and the second moment; Based on the echo energy change information, it is determined whether the target to be identified is a false target.
2. The false target identification method according to claim 1, characterized in that: The step of obtaining the location information of the target to be identified includes: Obtain the echo signal at the first moment and the track information within a preset time range; Determine at least one detection target based on the echo signal at the first moment; Matching at least one detected target with the track information; The detected target that fails to match is regarded as the new target appearing at the first moment.
3. The false target identification method according to claim 1, characterized in that: The position information also includes a target distance and a target speed; and adjusting the phase of the transmission signal at the second moment based on the position information of the target to be identified includes: Calculating an offset phase based on the position information of the target to be identified; Based on the offset phase, the phase of the transmission signal at the second moment is adjusted.
4. The false target identification method according to claim 1, characterized in that: The echo energy change information includes a first normalized power distribution, a second normalized power distribution, and an energy change distribution; and the calculating the echo energy change information at the first moment and the second moment based on the echo signals at the first moment and the second moment includes: Calculating a first normalized power distribution at the first moment based on the echo signal at the first moment; Calculating a second normalized power distribution at the second moment based on the echo signal at the second moment; Based on the first normalized power distribution and the second normalized power distribution, energy change distributions at the first moment and the second moment are determined.
5. The false target identification method according to claim 4, characterized in that: The first normalized power distribution and the second normalized power distribution respectively include normalized powers at multiple azimuths, and determining the energy change distribution at the first moment and the second moment based on the first normalized power distribution and the second normalized power distribution includes: Determine a normalized power change value at each azimuth based on normalized power values of multiple azimuths in the first normalized power distribution and the second normalized power distribution; Based on the normalized power change values at multiple azimuth angles, an energy change distribution is determined.
6. The false target identification method according to claim 5, characterized in that: The determining whether the target to be identified is a false target based on the echo energy change information includes: Determine a normalized power change value corresponding to the azimuth of the target to be identified based on the energy change distribution and the target angle of the target to be identified; If the normalized power change value is greater than a preset change threshold, the target to be identified is a real target; if the normalized power change value is less than or equal to the preset change threshold, the target to be identified is a false target.
7. The false target identification method according to claim 6, characterized in that: If the normalized power change value is greater than a preset change threshold, the target to be identified is a real target before comprising: Determine a main-to-sidelobe ratio threshold value based on the main-to-sidelobe ratio in the first normalized power distribution and / or the second normalized power distribution; The main-to-sidelobe ratio threshold value is used as a preset change threshold value.
8. A false target identification device, characterized in that: The device comprises: An acquisition module, used to acquire the position information of a target to be identified; the target to be identified is a new target that appears at the first moment; An adjustment module, configured to adjust the phase of the transmission signal at a second moment based on the position information of the target to be identified; A calculation module, used to calculate the echo energy change information at the first moment and the second moment based on the echo signals at the first moment and the second moment; A judgment module is used to judge whether the target to be identified is a false target based on the echo energy change information.
9. A computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the method according to any one of claims 1 to 7 is implemented.
10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the method according to any one of claims 1 to 7 is implemented.