A method for identifying image targets of vehicle-mounted millimeter-wave radar on straight roads

Abstract

The present invention relates to the field of traffic safety, and more specifically, to a method for identifying mirrored targets in a vehicle-mounted millimeter-wave radar on a straight road. This method identifies mirrored targets that appear in the millimeter-wave radar image on a straight road, eliminating potential safety hazards caused by mirrored targets, preventing them from affecting advanced driver assistance systems, and ensuring vehicle safety.

Description

Technical Field

[0001] The present invention relates to the field of traffic safety, and in particular to a method for identifying a mirror image target of a vehicle-mounted millimeter-wave radar on a straight road. Background Art

[0002] Automotive millimeter-wave radar is often used to track and measure vehicles ahead. Due to its excellent tracking performance, it is widely used. However, in actual use, millimeter-wave radar often encounters problems when tracking targets. A common problem is the identification of false targets. This is especially true when there is a guardrail or other metal anti-glare plate on the left side of the road. Radar waves are emitted from this surface and return when they hit the vehicle ahead, resulting in the appearance of a mirrored target located in front of the left vehicle during the identification process. Especially on straight roads, when there is a guardrail or metal anti-glare plate on the left side, the mirrored target will remain. This has a serious impact on the operation of the Advanced Driving Assistance System (ADAS) and poses a significant safety hazard. Therefore, the problem of mirrored targets during radar use needs to be urgently addressed. Summary of the Invention

[0003] In view of the problems existing in the prior art, the object of the present invention is to provide a method for identifying image targets of vehicle-mounted millimeter-wave radar on a straight road.

[0004] In order to achieve the above objectives, the present invention adopts the following technical solutions to achieve them.

[0005] A method for identifying a vehicle-mounted millimeter-wave radar mirror target on a straight road comprises the following steps:

[0006] Step 1: When the vehicle-mounted millimeter-wave radar identifies multiple vehicles on a straight road, the actual relative angle, actual relative linear distance, and actual relative lateral distance between each vehicle and the millimeter-wave radar are obtained respectively;

[0007] Step 2, calculating the relative straight-line distance correlation or relative lateral distance correlation between two vehicles;

[0008] Step 3: When the relative straight-line distance correlation or relative lateral distance correlation of any two vehicles is greater than a correlation threshold, there is a mirror image target between the two target vehicles;

[0009] Step 4: Of the two target vehicles, the target vehicle with the smaller relative straight-line distance to the millimeter-wave radar is the mirror image target of the other target vehicle.

[0010] Compared with the existing technology, the beneficial effects of the present invention are: identifying the mirror targets that appear in the millimeter-wave radar on a straight road, eliminating the safety hazards of the vehicle caused by the mirror targets, avoiding the impact of the mirror targets on the advanced driver assistance system, and ensuring the driving safety of the vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0012] Figure 1 is a flow chart of the method of the present invention;

[0013] Figure 2 Schematic diagram of the geometric relationship between the vehicle and surrounding vehicles. DETAILED DESCRIPTION

[0014] The embodiments of the present invention will be described in detail below with reference to examples. However, those skilled in the art will understand that the following examples are only used to illustrate the present invention and should not be construed as limiting the scope of the present invention.

[0015] refer to Figure 1 A method for identifying a vehicle-mounted millimeter-wave radar mirror target on a straight road comprises the following steps:

[0016] Step 1: When the vehicle-mounted millimeter-wave radar identifies multiple vehicles on a straight road, the actual relative angle, actual relative linear distance, and actual relative lateral distance between each vehicle and the millimeter-wave radar are obtained respectively; the vehicle-mounted millimeter-wave radar is installed on the vehicle.

[0017] Step 2: Calculate the relative straight-line distance correlation or relative lateral distance correlation between two vehicles;

[0018] Calculate the correlation between the relative straight-line distances between each vehicle. Specifically, when the change in the distance between the vehicle and the left lane line is less than 5 cm, and the actual relative straight-line distance change between one or more vehicles and the millimeter-wave radar is greater than or equal to 5 meters, mark the vehicles whose actual relative straight-line distance change is greater than or equal to 5 meters. Calculate the correlation between the relative straight-line distances of any marked vehicle and all other vehicles during the change in relative straight-line distance, until the correlations between the relative straight-line distances of all marked vehicles and all other vehicles during the change in relative straight-line distance are calculated.

[0019] The sub-steps for calculating the correlation between the relative straight-line distances between any marked vehicle and all other vehicles during the relative straight-line distance change process are as follows:

[0020] First, during the process of the actual relative straight-line distance between the marked vehicle and the millimeter-wave radar changing from 0 to 5m, the millimeter-wave radar collects the actual relative angles and actual relative straight-line distances of all vehicles and the millimeter-wave radar N times. Therefore, there are N actual relative straight-line distances D0 between the marked vehicle and the millimeter-wave radar, N actual relative angles A0 between the marked vehicle and the millimeter-wave radar, and N actual relative angles A0 between the surrounding i-th vehicle and the millimeter-wave radar. i , and the actual relative straight-line distance D between the N surrounding i-th vehicle and the millimeter-wave radar i ;

[0021] Secondly, reference Figure 2 Calculate the relative straight-line distance D′ between the surrounding i-th vehicle and the millimeter-wave radar when it is the mirror target of the marked vehicle i , the calculation formula is as follows, and N D′ is obtained i ;

[0022]

[0023] Where D′ i is the relative straight-line distance between the surrounding i-th vehicle and the millimeter-wave radar when it is the mirror target of the marked vehicle, D0 is the actual relative straight-line distance between the marked vehicle and the millimeter-wave radar, and A i is the actual relative angle between the surrounding i-th vehicle and the millimeter-wave radar, and A0 is the actual relative angle between the marked vehicle and the millimeter-wave radar;

[0024] Finally, calculate the relative straight-line distance D′ between the surrounding i-th vehicle and the millimeter-wave radar when it is the mirror image target of the marked target i The actual relative straight-line distance D between the surrounding i-th vehicle and the millimeter-wave radar i The correlation coefficient r1 is calculated as follows:

[0025]

[0026] Calculate the relative lateral distance correlation between each vehicle. Specifically, when the distance between the vehicle and the left lane line changes by greater than or equal to 45 cm, calculate the relative lateral distance correlation between any vehicle and other vehicles during the relative lateral distance change, until all relative lateral distance correlations between each vehicle and other vehicles during the relative lateral distance change are calculated.

[0027] The sub-steps for calculating the correlation between the relative lateral distances between any vehicle and other vehicles during the relative lateral distance change process are as follows:

[0028] First, as the distance between the vehicle and the left lane changes from 0 to 45 cm, the millimeter-wave radar collects N actual relative angles and actual relative lateral distances between all vehicles and the millimeter-wave radar. Therefore, there are N actual relative lateral distances L0 between the vehicle and the millimeter-wave radar, N actual relative angles A0 between the vehicle and the millimeter-wave radar, and N actual relative angles A0 between the surrounding i-th vehicle and the millimeter-wave radar. i , and the actual relative lateral distance L between the N surrounding i-th vehicle and the millimeter-wave radar i ;

[0029] Secondly, reference Figure 2 Calculate the relative lateral distance L′ between the surrounding vehicle i and the millimeter-wave radar when the vehicle is the mirror target of the vehicle i , the calculation formula is as follows, and N L' is obtained i ;

[0030]

[0031] Where L′ i is the relative lateral distance between the surrounding vehicle i and the millimeter-wave radar when it is the mirror target of the vehicle, L0 is the actual relative lateral distance between the vehicle and the millimeter-wave radar, and A i is the actual relative angle between the i-th vehicle and the millimeter-wave radar, and A0 is the actual relative angle between the vehicle and the millimeter-wave radar;

[0032] Finally, calculate the relative lateral distance L′ between the surrounding i-th vehicle and the millimeter-wave radar when it is the mirror target of the vehicle i The actual relative lateral distance L between the surrounding i-th vehicle and the millimeter-wave radar i The correlation coefficient r2 is calculated as follows:

[0033]

[0034] The distance between the vehicle and the left lane line can be obtained using a lane line distance sensor.

[0035] Step 3: When the relative straight-line distance correlation or relative lateral distance correlation of any two vehicles is greater than a correlation threshold, there is a mirror image target between the two target vehicles;

[0036] Specifically, the correlation threshold is 0.95.

[0037] Step 4: Of the two target vehicles, the target vehicle with the smaller relative straight-line distance to the millimeter-wave radar is the mirror image target of the other target vehicle.

[0038] After the mirrored targets are identified, they are removed and the remaining targets are input into the advanced driver assistance system to prevent the mirrored targets from affecting the advanced driver assistance system and ensure the driving safety of the vehicle.

[0039] Although this specification has provided a detailed description of the present invention using general descriptions and specific embodiments, it will be apparent to those skilled in the art that modifications and improvements may be made based on the present invention. Therefore, such modifications and improvements, which do not depart from the spirit of the present invention, are intended to be within the scope of protection claimed herein.

Claims

1. A method for identifying image targets of vehicle-mounted millimeter-wave radar on a straight road, characterized in that: The following steps are involved: Step 1: When the vehicle-mounted millimeter-wave radar identifies multiple vehicles on a straight road, the actual relative angle, actual relative linear distance, and actual relative lateral distance between each vehicle and the millimeter-wave radar are obtained respectively; Step 2: Calculate the relative straight-line distance correlation between two vehicles; Step 3: When the correlation of the relative straight-line distances between any two vehicles is greater than the correlation threshold, there is a mirror target between the two target vehicles; Step 4: The target vehicle with the smaller relative straight-line distance to the millimeter-wave radar among the two target vehicles is the mirror image target of the other target vehicle; In step 2, the relative straight-line distance correlation between each pair of vehicles is calculated. Specifically, when the distance change between the vehicle and the left lane line is less than 5 cm, and the actual relative straight-line distance change between one or more vehicles and the millimeter-wave radar is greater than or equal to 5 meters, the vehicles whose actual relative straight-line distance change between the vehicle and the millimeter-wave radar is greater than or equal to 5 meters are marked. The relative straight-line distance correlation between any marked vehicle and all other vehicles during the relative straight-line distance change is calculated until the relative straight-line distance correlation between all marked vehicles and all other vehicles during the relative straight-line distance change is calculated. The sub-steps for calculating the correlation between the relative straight-line distances between any marked vehicle and all other vehicles during the relative straight-line distance change process are as follows: First, during the process of the actual relative straight-line distance between the marked vehicle and the millimeter-wave radar changing from 0 to 5m, the millimeter-wave radar collects the actual relative angles and actual relative straight-line distances of all vehicles and the millimeter-wave radar N times. Therefore, there are N actual relative straight-line distances D0 between the marked vehicle and the millimeter-wave radar, N actual relative angles A0 between the marked vehicle and the millimeter-wave radar, and N actual relative angles A0 between the surrounding i-th vehicle and the millimeter-wave radar. i , and the actual relative straight-line distance D between the N surrounding i-th vehicle and the millimeter-wave radar i ; Secondly, calculate the relative straight-line distance D′ between the surrounding i-th vehicle and the millimeter-wave radar when it is the mirror target of the marked vehicle i , the calculation formula is as follows, and N D′ is obtained i ; Where D′ i is the relative straight-line distance between the surrounding i-th vehicle and the millimeter-wave radar when it is the mirror target of the marked vehicle, D0 is the actual relative straight-line distance between the marked vehicle and the millimeter-wave radar, and A i is the actual relative angle between the surrounding i-th vehicle and the millimeter-wave radar, and A0 is the actual relative angle between the marked vehicle and the millimeter-wave radar; Finally, calculate the relative straight-line distance D′ between the surrounding i-th vehicle and the millimeter-wave radar when it is the mirror target of the marked vehicle i The actual relative straight-line distance D between the surrounding i-th vehicle and the millimeter-wave radar i The correlation coefficient r1 is calculated as follows:

2. A method for identifying image targets of vehicle-mounted millimeter-wave radar on a straight road, characterized in that: The following steps are involved: Step 1: When the vehicle-mounted millimeter-wave radar identifies multiple vehicles on a straight road, the actual relative angle, actual relative linear distance, and actual relative lateral distance between each vehicle and the millimeter-wave radar are obtained respectively; Step 2: Calculate the relative lateral distance correlation between two vehicles; Step 3: When the correlation between the relative lateral distances of any two vehicles is greater than a correlation threshold, there is a mirror image target between the two target vehicles; Step 4: The target vehicle with the smaller relative straight-line distance to the millimeter-wave radar among the two target vehicles is the mirror image target of the other target vehicle; In step 2, the relative lateral distance correlation between each vehicle is calculated. Specifically, when the distance change between the vehicle and the left lane line is greater than or equal to 45 cm, the relative lateral distance correlation between any vehicle and other vehicles during the relative lateral distance change is calculated until the relative lateral distance correlation between each vehicle and other vehicles during the relative lateral distance change is calculated. The sub-steps for calculating the correlation between the relative lateral distances between any vehicle and other vehicles during the relative lateral distance change process are as follows: First, as the distance between the vehicle and the left lane changes from 0 to 45 cm, the millimeter-wave radar collects N actual relative angles and actual relative lateral distances between all vehicles and the millimeter-wave radar. Therefore, there are N actual relative lateral distances L0 between the vehicle and the millimeter-wave radar, N actual relative angles A0 between the vehicle and the millimeter-wave radar, and N actual relative angles A0 between the surrounding i-th vehicle and the millimeter-wave radar. i , and the actual relative lateral distance L between the N surrounding i-th vehicle and the millimeter-wave radar i ; Secondly, calculate the relative lateral distance L′ between the surrounding vehicle i and the millimeter-wave radar when it is the mirror target of the vehicle i , the calculation formula is as follows, and N L' is obtained i ; Where L′ i is the relative lateral distance between the surrounding vehicle i and the millimeter-wave radar when it is the mirror target of the vehicle, L0 is the actual relative lateral distance between the vehicle and the millimeter-wave radar, and A i is the actual relative angle between the i-th vehicle and the millimeter-wave radar, and A0 is the actual relative angle between the vehicle and the millimeter-wave radar; Finally, calculate the relative lateral distance L′ between the surrounding i-th vehicle and the millimeter-wave radar when it is the mirror target of the vehicle i The actual relative lateral distance L between the surrounding i-th vehicle and the millimeter-wave radar i The correlation coefficient r2 is calculated as follows:

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