Radar target matching method

Abstract

This invention relates to a radar target matching method. The method includes: step S1, selecting the first target in a target list; step S2, selecting the first point in a point list; step S3, selecting an observation dimension based on the target's position; step S4, calculating the difference between the predicted value of the target and the observed value of the point based on the selected observation dimension; step S5, comparing the difference with a threshold of the selected observation dimension, and finding matches where the difference is simultaneously less than the threshold; step S6, summing the differences and comparing the sum with previously recorded matching data, recording the match with the smallest sum and the match with the second smallest sum. The solution provided by this invention facilitates multi-target matching.

Description

Technical Field

[0001] This invention relates to the field of radar signal processing technology, and more specifically to a target matching method for vehicle-mounted millimeter-wave radar. Background Technology

[0002] When performing multi-target tracking, vehicle-mounted millimeter-wave radar needs to correlate the positions of the same target at different times. This process is called multi-target matching. Existing matching methods mostly employ nearest neighbor or joint probabilistic data interconnection. The joint probabilistic data interconnection method, due to its massive computational complexity, is only suitable for scientific research and not for engineering implementation. The nearest neighbor method is simple in its matching approach, but because it uses the same threshold across all regions, a threshold that works at close range may fail at greater distances. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a radar target matching method that can achieve multi-target matching.

[0004] To address the aforementioned technical problems, this invention provides a radar target matching method applicable to vehicle radar, comprising:

[0005] Step S1: Select one target from the target list;

[0006] Step S2: Select a point from the point list;

[0007] Step S3: Select the observation dimension based on the location of the target;

[0008] Step S4: Calculate the difference between the predicted value of the target and the observed value of the point based on the selected observation dimension;

[0009] Step S5: Compare the difference with the threshold of the selected observation dimension respectively, and find the match where the difference is less than the threshold at the same time;

[0010] Step S6: Sum the differences and compare them with the recorded matching data of difference sums. Record the match with the smallest difference sum and the match with the second smallest difference sum.

[0011] Step S7: Traverse each point in the point list and repeat steps S3-S6.

[0012] Step S8: If the point corresponding to the match with the smallest difference sum is not used, then the smallest match is used as the match between the target and the point; if the point corresponding to the match with the smallest difference sum has been used, then the difference sum between the point and the current target and the matched target is compared. If the difference sum of the current target is smaller, then the match with the smallest difference sum is selected, otherwise the match with the second smallest difference sum is selected.

[0013] Step S9: Iterate through each target in the target list and repeat steps S2-S8.

[0014] According to an embodiment of the present invention, in step S3, when the target is at a distance greater than or equal to a first length, a Cartesian coordinate system is used as the observation dimension; when the target is at a distance less than or equal to a second length, a cylindrical coordinate system is used as the observation dimension; when the target is at a distance less than the first length and greater than the second length, the target is placed in a buffer, and a Cartesian coordinate system and a cylindrical coordinate system are used as the observation dimensions.

[0015] According to an embodiment of the present invention, in step S3, when the target is at a distance greater than or equal to a first length, the X-axis and Y-axis of the Cartesian coordinate system are used as the observation dimensions; when the target is at a distance less than or equal to a second length, the R-axis and Theta-axis of the cylindrical coordinate system are used as the observation dimensions; when the target is at a distance less than the first length but greater than the second length, the target is placed in a buffer, and the X-axis and Y-axis of the Cartesian coordinate system and the R-axis and Theta-axis of the cylindrical coordinate system are used as the observation dimensions.

[0016] According to one embodiment of the present invention, in step S3, the first length is 75 to 85 meters and the second length is 25 to 35 meters.

[0017] According to one embodiment of the present invention, in step S3, the first length is 80 meters and the second length is 30 meters.

[0018] According to one embodiment of the present invention, in step S5, the threshold is determined according to the radar model.

[0019] The present invention provides a radar target matching method that uses different observation dimensions and corresponding thresholds in different regions to effectively complete multi-target matching. Attached Figure Description

[0020] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings, wherein:

[0021] Figure 1 This is a flowchart of a radar target matching method according to an embodiment of the present invention;

[0022] Figure 2 This is a schematic diagram of a radar target matching method according to an embodiment of the present invention, showing the division of regions. Detailed Implementation

[0023] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0024] Numerous specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and therefore the invention is not limited to the specific embodiments disclosed below.

[0025] As indicated in this application and claims, unless the context clearly indicates otherwise, the words "a," "an," "an," and / or "the" are not specifically singular and may include plural forms. Generally speaking, the terms "comprising" and "including" only indicate the inclusion of explicitly identified steps and elements, which do not constitute an exclusive list, and the method or apparatus may also include other steps or elements.

[0026] In detailing the embodiments of this application, for ease of explanation, the cross-sectional views illustrating the device structure will be partially enlarged and not to scale. Furthermore, the schematic diagrams are merely examples and should not limit the scope of protection of this application. In actual fabrication, the three-dimensional spatial dimensions of length, width, and depth should be included.

[0027] For ease of description, spatial relation terms such as “below,” “below,” “lower than,” “below,” “above,” “upper,” etc., may be used herein to describe the relationship of an element or feature shown in the accompanying drawings to other elements or features. It will be understood that these spatial relation terms are intended to include orientations of the device in use or operation other than those depicted in the accompanying drawings. For example, if the device in the accompanying drawings is flipped, the orientation of an element described as “below,” “below,” or “below” to other elements or features will change to “above” said other elements or features. Thus, the exemplary terms “below” and “below” can encompass both upward and downward directions. The device may also have other orientations (rotated 90 degrees or in other orientations), and therefore the spatial relation descriptors used herein should be interpreted accordingly. Furthermore, it will be understood that when a layer is referred to as being “between” two layers, it can be the only layer between the two layers, or there may be one or more layers in between.

[0028] In the context of this application, the structure described above the second feature may include embodiments in which the first and second features are formed in direct contact, or embodiments in which additional features are formed between the first and second features, such that the first and second features may not be in direct contact.

[0029] Figure 1 This is a flowchart of a radar target matching method according to an embodiment of the present invention. Figure 2 This is a schematic diagram of a radar target matching method according to an embodiment of the present invention, showing the division of regions.

[0030] As shown in the figure, a radar target matching method includes:

[0031] Step S1: Select one target from the target list. The target list contains multiple targets, which are selected sequentially.

[0032] Step S2: Select a point from the point list. The point list contains multiple points, each corresponding to a target's location. Target matching here means matching a target in the target list with a point in the point list; that is, associating a target with a point.

[0033] Step S3: Select the observation dimension based on the target's location.

[0034] Step S4: Calculate the difference between the predicted value of the target and the observed value of the point, based on the selected observation dimension. It should be noted that the target has multiple attributes such as position and velocity. The predicted value here is used to estimate the target's position from the current moment to the next moment based on these attributes. The observed value of the point refers to its observed location.

[0035] Step S5 involves comparing the differences with thresholds, finding matches where the differences are simultaneously less than the thresholds. Specifically, different observation dimensions have their own thresholds. For example, a Cartesian coordinate system has at least two dimensions, each with its own threshold. The differences between the predicted value of the target and the observed value of the point are calculated in each of these two dimensions. If both differences are less than the thresholds of the two Cartesian coordinate dimensions, the currently selected target and point are considered a match. It should be noted that different observation dimensions can be selected for different regions, and different thresholds can be set for different observation dimensions.

[0036] Step S6: Sum the differences and compare the sum with the recorded matching data. Record the match with the smallest sum of differences and the match with the second smallest sum of differences. The recorded matching data refers to the matches with the already acquired sums of differences. Through iterative calculation, the match with the smallest sum of differences and the match with the second smallest sum of differences are obtained. Ultimately, only two sets of matches are retained. For example, the first set includes target A1 and point B1, which is the smallest match; the second set includes target A1 and point B2, which is the second smallest match.

[0037] Step S7: Iterate through each point in the point list, repeating steps S3-S6. This will ultimately yield two sets of matches; for example, the first set includes target A1 and point B. m The first group is the minimum matching; the second group includes target A1 and point B. n This is the second smallest match.

[0038] Step S8: If the point corresponding to the match with the smallest difference sum is not used, then use that smallest match as the target-point match. "Not used" means the current point has not been matched by any other target; therefore, target A1 and point B...m As the matching result. If the point corresponding to the match with the smallest difference sum has already been used, then compare the sum of differences between the current target A1 and the already matched targets. If the sum of differences of the current target is smaller, then select the match with the smallest difference sum, that is, target A1 and point B. m This is used as the matching result. Conversely, the difference and the second smallest match are selected, i.e., target A1 and point B. n As a matching result.

[0039] Step S9: Traverse each target in the target list and repeat steps S2-S8 to obtain the matching result between each target and its corresponding point.

[0040] Preferably, in step S3, when the target is at a distance greater than or equal to the first length L1, a Cartesian coordinate system is used as the observation dimension; when the target is at a distance less than or equal to the second length L2, a cylindrical coordinate system is used as the observation dimension; when the target is at a distance less than the first length L1 but greater than the second length L2, the target is placed in a buffer, and both Cartesian and cylindrical coordinate systems are used as observation dimensions. The first length L1 is greater than the second length L2. Step S3 selects different regions based on the target's position and chooses different observation dimensions for each region. Simultaneously, a buffer is established; when the target is at a distance less than the first length L1 but greater than the second length L2, the target is placed in the buffer, and both Cartesian and cylindrical coordinate systems are used as observation dimensions. Both observation dimensions are incorporated into subsequent calculations. (Reference) Figure 2 The sector-shaped area originating from point O is divided into three regions: the far-distance region 201, the intermediate region 202, and the near-distance region 203. When the target is at a distance greater than or equal to the first length L1, the target is located in the far-distance region 201, and the Cartesian coordinate system is used as the observation dimension. When the target is at a distance less than or equal to the second length L2, the target is located in the near-distance region 203, and the cylindrical coordinate system is used as the observation dimension. When the target is at a distance less than the first length L1 but greater than the second length L2, the target is located in the intermediate region 202, and the target is placed in a buffer zone, using both Cartesian and cylindrical coordinate systems as the observation dimensions.

[0041] Preferably, in step S3, when the target is at a distance greater than or equal to the first length L1, the X-axis and Y-axis of the Cartesian coordinate system are used as the observation dimensions; when the target is at a distance less than or equal to the second length L2, the R-axis and Theta-axis of the cylindrical coordinate system are used as the observation dimensions; when the target is at a distance less than the first length L1 and greater than the second length L2, the target is placed in a buffer, and the X-axis and Y-axis of the Cartesian coordinate system and the R-axis and Theta-axis of the cylindrical coordinate system are used as the observation dimensions.

[0042] Preferably, in step S3, the first length L1 is 75-85 meters and the second length L2 is 25-35 meters. More preferably, in step S3, the first length L1 is 80 meters and the second length L2 is 30 meters.

[0043] Preferably, in step S5, the threshold is determined according to the radar model.

[0044] The present invention provides a radar target matching method that uses different matching elements and thresholds in different regions, which solves the problem that the near-range threshold fails at long range; at the same time, a buffer zone is established to solve the problem that different elements cannot be compared when crossing regions.

[0045] Although the present invention has been described with reference to specific embodiments, those skilled in the art should recognize that the above embodiments are merely illustrative of the invention, and various equivalent changes or substitutions can be made without departing from the spirit of the invention. Therefore, any changes or modifications to the above embodiments within the essential spirit of the invention will fall within the scope of the claims of this application.

Claims

1. A radar target matching method, comprising: Step S1: Select one target from the target list; Step S2: Select a point from the point list; Step S3: Select the observation dimension based on the position of the target; when the target is at a distance greater than or equal to the first length, use the Cartesian coordinate system as the observation dimension. When the target is at a distance less than or equal to the second length, cylindrical coordinates are used as the observation dimension. When the target is at a distance less than the first length and greater than the second length, the target is placed in the buffer, and the Cartesian coordinate system and cylindrical coordinate system are used as the observation dimensions. Step S4: Calculate the difference between the predicted value of the target and the observed value of the point based on the selected observation dimension; Step S5: Compare the difference with the threshold of the selected observation dimension respectively, and find the match where the difference is less than the threshold at the same time; Step S6: Sum the differences and compare them with the recorded matching data of difference sums. Record the match with the smallest difference sum and the match with the second smallest difference sum. Step S7: Traverse each point in the point list and repeat steps S3-S6. Step S8: If the point corresponding to the match with the smallest difference sum is not used, then the smallest match is used as the match between the target and the point; if the point corresponding to the match with the smallest difference sum has been used, then the difference sum between the point and the current target and the matched target is compared. If the difference sum of the current target is smaller, then the match with the smallest difference sum is selected, otherwise the match with the second smallest difference sum is selected. Step S9: Iterate through each target in the target list and repeat steps S2-S8.

2. The radar target matching method of claim 1, wherein, In step S3, when the target is at a distance greater than or equal to the first length, the X and Y axes of the Cartesian coordinate system are used as the observation dimensions; when the target is at a distance less than or equal to the second length, the R and Theta axes of the cylindrical coordinate system are used as the observation dimensions. When the target is at a distance less than the first length and greater than the second length, the target is placed in a buffer, and the X and Y axes of the Cartesian coordinate system and the R and Theta axes of the cylindrical coordinate system are used as the observation dimensions.

3. The radar target matching method of claim 1, wherein, In step S3, the first length is 75-85 meters and the second length is 25-35 meters.

4. The radar target matching method of claim 3, wherein, In step S3, the first length is 80 meters and the second length is 30 meters.

5. The radar target matching method of claim 1, wherein, In step S5, the threshold is determined according to the radar model.

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