Millimeter wave radar calibration method and device, vehicle

Abstract

The application relates to a calibration method of a millimeter wave radar, which is used for position identification of a first millimeter wave radar and a second millimeter wave radar symmetrically installed at the tail of a vehicle, and comprises the following steps: in the process that the vehicle travels along a straight line, the first millimeter wave radar and the second millimeter wave radar are controlled to respectively emit a first radar signal and a second radar signal; a point set of a first target object collected by the first millimeter wave radar at at least two time points is acquired, and a point set of a second target object collected by the second millimeter wave radar at at least two time points is acquired, wherein the first target object and the second target object are static objects respectively located on the two sides of the vehicle; and the position of the first millimeter wave radar and the second millimeter wave radar is identified according to the point set of the first target object and the point set of the second target object. The application also relates to a calibration device of a millimeter wave radar and a vehicle. According to the application, the installation position of the radar can be calibrated at low cost and simply.

Description

Technical Field

[0001] This invention relates to the field of vehicle-mounted radar technology, and more specifically, to a millimeter-wave radar calibration method, a millimeter-wave radar calibration device, and a vehicle. Background Technology

[0002] With the rapid development of automotive millimeter-wave radar technology, it has become an indispensable sensor in the fields of driver assistance and autonomous driving. Currently, the main installation schemes for automotive millimeter-wave radar are the 1+2 and 1+4 schemes, where 2 and 4 refer to the number of corner radars. For example, with two corner radars, two rear-facing corner radars can be symmetrically installed at the rear of the vehicle, primarily used to observe the area behind the vehicle, enabling blind spot detection, lane change assistance, and rear collision warning. Furthermore, to save on vehicle wiring and system costs, these corner radars are often connected to the same CAN network. While the two corner radars have no fundamental design differences, they need to determine their installation positions and output the corresponding target to the central controller according to the agreed-upon CAN protocol. Summary of the Invention

[0003] This invention was made to solve the above-mentioned problems, and its purpose is to provide a radar calibration method and apparatus that can calibrate the installation position of the radar in a low-cost and simple manner after leaving the factory.

[0004] According to one aspect of the present invention, a calibration method for millimeter-wave radar is provided for position identification of a first millimeter-wave radar and a second millimeter-wave radar symmetrically mounted at the rear of a vehicle, comprising: a signal transmission step, wherein, while the vehicle is traveling in a straight line, the first millimeter-wave radar and the second millimeter-wave radar respectively transmit a first radar signal and a second radar signal; a data acquisition step, wherein the first millimeter-wave radar acquires a set of points of a first target object at at least two time moments, and acquires a set of points of a second target object at at least two time moments, wherein the first target object and the second target object are static objects located on opposite sides of the vehicle; and a position identification step, wherein the first millimeter-wave radar and the second millimeter-wave radar are positioned based on the set of points of the first target object and the set of points of the second target object.

[0005] Preferably, in the location identification step, a first motion trajectory of the first target object relative to the first millimeter-wave radar is obtained based on the point set of the first target object, a second motion trajectory of the second target object relative to the second millimeter-wave radar is obtained based on the point set of the second target object, and the location of the first millimeter-wave radar and the second millimeter-wave radar is identified based on the first motion trajectory and the second motion trajectory.

[0006] Preferably, in the location recognition step, if the first motion trajectory or the second motion trajectory represents a motion trajectory from left to right, then it is determined that the first millimeter-wave radar or the second millimeter-wave radar is installed on the left side of the vehicle; if the first motion trajectory or the second motion trajectory represents a motion trajectory from right to left, then it is determined that the first millimeter-wave radar or the second millimeter-wave radar is installed on the right side of the vehicle.

[0007] Preferably, the calibration method for the millimeter-wave radar further includes a cross-confirmation step, in which, if both the first millimeter-wave radar and the second millimeter-wave radar are identified as being located on the left or right side of the vehicle, information indicating a calibration error is output.

[0008] Preferably, the vehicle travels in a straight line at a speed of 30 kph or greater.

[0009] Preferably, for the first and second target objects at different locations, the signal transmission step, acquisition step, and location identification step are repeated n times. If the results of the n location identifications are consistent, they are taken as the final identification result. If the results of the n location identifications are inconsistent, information indicating that a calibration error has occurred is output.

[0010] According to another aspect of the present invention, a calibration device for millimeter-wave radar is provided for position identification of a first millimeter-wave radar and a second millimeter-wave radar installed at the rear of a vehicle, comprising: a signal transmitting module, which controls the first millimeter-wave radar and the second millimeter-wave radar to transmit a first radar signal and a second radar signal respectively while the vehicle is traveling in a straight line; a data acquisition module, which acquires a set of points of a first target object collected by the first millimeter-wave radar at at least two times, and acquires a set of points of a second target object collected by the second millimeter-wave radar at at least two times, wherein the first target object and the second target object are static objects located on opposite sides of the vehicle; and a position identification module, which identifies the positions of the first millimeter-wave radar and the second millimeter-wave radar based on the set of points of the first target object and the set of points of the second target object.

[0011] Preferably, in the location identification module, a first motion trajectory of the first target object relative to the first millimeter-wave radar is obtained based on the point set of the first target object, a second motion trajectory of the second target object relative to the first millimeter-wave radar is obtained based on the point set of the second target object, and the location of the first millimeter-wave radar and the second millimeter-wave radar is identified based on the first motion trajectory and the second motion trajectory.

[0012] Preferably, in the location recognition module, if the first motion trajectory or the second motion trajectory represents a motion trajectory from left to right, then it is determined that the first millimeter-wave radar or the second millimeter-wave radar is installed on the left side of the vehicle; if the first motion trajectory or the second motion trajectory represents a motion trajectory from right to left, then it is determined that the first millimeter-wave radar or the second millimeter-wave radar is installed on the right side of the vehicle.

[0013] According to another aspect of the present invention, a vehicle is provided, comprising: a first millimeter-wave radar and a second millimeter-wave radar, the first millimeter-wave radar and the second millimeter-wave radar being symmetrically mounted at the rear of the vehicle; and a controller, the controller being communicatively connected to the first millimeter-wave radar and the second millimeter-wave radar respectively, for executing the calibration method of the millimeter-wave radar according to any one of the above embodiments.

[0014] According to the present invention, the installation position of the radar can be calibrated at low cost and easily after leaving the factory. Attached Figure Description

[0015] Figure 1 This is a schematic flowchart of a millimeter-wave radar calibration method according to an embodiment of the present invention.

[0016] Figure 2 This is a schematic diagram of a millimeter-wave radar calibration method according to an embodiment of the present invention.

[0017] Figure 3 This is a schematic diagram of the first motion trajectory in one embodiment of the present invention.

[0018] Figure 4 This is a schematic diagram of the second motion trajectory in one embodiment of the present invention.

[0019] Figure 5 This is a structural block diagram of a millimeter-wave radar calibration device according to an embodiment of the present invention.

[0020] Figure 6 This is a structural block diagram of a vehicle according to an embodiment of the present invention. Detailed Implementation

[0021] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, only the parts relevant to the invention are shown in the accompanying drawings.

[0022] The embodiments described herein can be described with reference to plan views and / or cross-sectional views using the ideal schematic diagrams of this disclosure. Therefore, the example illustrations can be modified according to manufacturing techniques and / or tolerances. Therefore, the embodiments are not limited to those shown in the drawings, but include modifications to configurations formed based on manufacturing processes. Therefore, the areas illustrated in the drawings are schematic in nature, and the shapes of the areas shown in the figures illustrate specific shapes of areas of an element, but are not intended to be limiting.

[0023] Unless otherwise specified, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art. It will also be understood that terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant art and this disclosure, and will not be interpreted as having an idealized or overly formal meaning, unless expressly so defined herein.

[0024] Figure 1 This is a schematic flowchart of a millimeter-wave radar calibration method according to an embodiment of the present invention. Figure 2 This is a schematic diagram of a millimeter-wave radar calibration method according to an embodiment of the present invention. Combined with... Figure 1 and Figure 2 The present invention describes a millimeter-wave radar calibration method according to an embodiment of the invention. This embodiment is applicable to the calibration of millimeter-wave radar after a vehicle leaves the factory, when the vehicle's equipment malfunctions, and during equipment maintenance.

[0025] like Figure 1 As shown, the millimeter-wave radar calibration method involved in this embodiment specifically includes the following steps.

[0026] S101. While the vehicle is traveling in a straight line, the first millimeter-wave radar 10 and the second millimeter-wave radar 20 are controlled to transmit the first radar signal and the second radar signal, respectively.

[0027] Millimeter-wave radar is a device installed on a vehicle that can transmit electromagnetic waves and receive electromagnetic waves reflected from a target through an antenna. It calculates various parameters of the target, such as distance, angle, and relative speed, by transmitting and receiving electromagnetic wave parameters.

[0028] Millimeter-wave radar's detection range can be a fan-shaped cone. Therefore, the first millimeter-wave radar 10 and the second millimeter-wave radar 20 are typically symmetrically mounted at the rear of the vehicle to comprehensively detect the area behind the vehicle, providing better environmental perception for assisted or autonomous driving systems. Figure 2 As shown, in this embodiment, the first millimeter-wave radar 10 is installed on the left side of the rear of the vehicle 1, and the second millimeter-wave radar 20 is installed on the right side of the rear of the vehicle 1.

[0029] When calibrating the first millimeter-wave radar 10 and the second millimeter-wave radar 20 for position identification, the vehicle is first driven in a straight line. During this process, the first millimeter-wave radar 10 and the second millimeter-wave radar 20 are controlled to transmit first radar signals and second radar signals, respectively. Here, driving in a straight line means that the yaw angle and steering angle of vehicle 1 are both 0. Furthermore, vehicle 1 preferably drives in a straight line at a speed of 30 kph or greater, which allows for more accurate target identification and tracking.

[0030] S102. Obtain the point sets of the first target object collected by the first millimeter-wave radar 10 at at least two time points, and obtain the point sets of the second target object collected by the second millimeter-wave radar 20 at at least two time points. The first target object 30 and the second target object 40 are static objects located on either side of the vehicle 1, such as roadside piers, signs, trees, utility poles, fences, etc. The collected point sets of the first target object 30 and the second target object 40 include the polar coordinates of the first target object 30 in the coordinate system of the first millimeter-wave radar 10 and the polar coordinates of the second target object 40 in the coordinate system of the second millimeter-wave radar 20. The point set of the first target object collected by the first millimeter-wave radar 10 at any time ti during the straight-line travel of the vehicle 1 can be denoted as S1i (i = 1, 2, ..., m), and the point set of the second target object collected by the second millimeter-wave radar 20 at any time ti during the straight-line travel of the vehicle 1 can be denoted as S2i (i = 1, 2, ..., m).

[0031] like Figure 2 As shown, the first target 30 and the second target 40 are located on both sides of the vehicle 1, and as the vehicle 1 moves, the first target 30 and the second target 40 will gradually enter the detection range of the first millimeter-wave radar 10 and the second millimeter-wave radar 20. When the first target 30 is within the detection range of the first millimeter-wave radar 10, the point sets of the first target 30 collected by the first millimeter-wave radar 10 at at least two moments are acquired; when the second target 40 is within the detection range of the second millimeter-wave radar 20, the point sets of the second target 40 collected by the second millimeter-wave radar 20 at at least two moments are acquired. In this embodiment, the point sets of the first target 30 collected by the first millimeter-wave radar 10 at four moments are acquired, i.e. Figure 2 As shown in S11, S12, S13, and S14, the point sets of the second target object 40 collected by the second millimeter-wave radar 20 at four different times are obtained, i.e. Figure 2 S21, S22, S23, and S24 are shown.

[0032] Figure 2In the illustration, the first and second targets are positioned symmetrically on either side of vehicle 1, and the point sets of the first and second targets are acquired almost synchronously. However, in actual calibration, this is not necessary. The first and second targets only need to be located on either side of vehicle 1. They do not need to be in a symmetrical position relative to vehicle 1, and the point sets of the first and second targets do not need to be acquired synchronously.

[0033] S103. The positions of the first millimeter-wave radar 10 and the second millimeter-wave radar 20 are identified based on the point set of the first target 30 and the point set of the second target 40.

[0034] Specifically, based on the point set S11, S12, S13, and S14 of the first target object 30 obtained in step S102, the first motion trajectory MT1 of the first target object 30 relative to the first millimeter-wave radar 10 is obtained, and based on the point set of the second target object 40, the second motion trajectory MT2 of the second target object 40 relative to the second millimeter-wave radar is obtained.

[0035] Figure 3 This is a schematic diagram showing the first motion trajectory MT1 of the first target object 30 relative to the first millimeter-wave radar 10 in this embodiment. Figure 4 This is a schematic diagram showing the second motion trajectory MT2 of the second target 40 relative to the second millimeter-wave radar 20 in this embodiment.

[0036] according to Figure 3 and Figure 4 As can be seen, for the first millimeter-wave radar 10 located on the left side of vehicle 1, the first motion trajectory MT1 shows a motion trajectory from left to right, while for the second millimeter-wave radar 20 located on the right side of vehicle 1, the second motion trajectory MT2 shows a motion trajectory from right to left. Therefore, the positions of the first and second millimeter-wave radars installed on the left and right sides of the rear of the vehicle can be identified based on the motion trajectories of the target object (first motion trajectory MT1 and second motion trajectory MT2).

[0037] If the first motion trajectory MT1 represents a left-to-right motion trajectory relative to the first millimeter-wave radar 10, then the first millimeter-wave radar 10 is determined to be installed on the left side of the vehicle; if the first motion trajectory MT1 represents a right-to-left motion trajectory relative to the first millimeter-wave radar 10, then the first millimeter-wave radar 10 is determined to be installed on the right side of the vehicle. Similarly, if the second motion trajectory MT2 represents a left-to-right motion trajectory relative to the second millimeter-wave radar 20, then the second millimeter-wave radar 20 is determined to be installed on the left side of the vehicle; if the second motion trajectory MT2 represents a right-to-left motion trajectory relative to the second millimeter-wave radar 20, then the second millimeter-wave radar 20 is determined to be installed on the right side of the vehicle.

[0038] In this embodiment, step S104 is preferred, in which, if both the first millimeter-wave radar 10 and the second millimeter-wave radar 20 are identified as being located on the left or right side of the vehicle, information indicating a calibration error is output.

[0039] Preferably, the calibration method of the millimeter-wave radar of the present invention does not perform the above steps S101 to S104 only once, but repeats steps S101 to S104 n times for the first target and the second target at different locations. If the results of the n location identifications are consistent, they are taken as the final identification result; if the results of the n location identifications are inconsistent, information indicating that a calibration error has occurred is output.

[0040] Figure 5 This is a structural block diagram of a millimeter-wave radar calibration device according to an embodiment of the present invention.

[0041] like Figure 5 As shown, the millimeter-wave radar calibration device 100 involved in this embodiment includes: a signal transmitting module 50, which controls the first millimeter-wave radar 10 and the second millimeter-wave radar 20 to transmit first radar signals and second radar signals respectively during the process of the vehicle 1 traveling in a straight line; an acquisition module 60, which acquires the point sets of the first target object 30 collected by the first millimeter-wave radar 10 at at least two moments, and acquires the point sets of the second target object 40 collected by the second millimeter-wave radar 20 at at least two moments, wherein the first target object 30 and the second target object 40 are static objects located on both sides of the vehicle 1 respectively; and a position recognition module 70, which performs position recognition on the first millimeter-wave radar 10 and the second millimeter-wave radar 20 based on the point sets of the first target object 30 and the second target object 40.

[0042] In the location recognition module 70, a first motion trajectory MT1 of the first target object 30 relative to the first millimeter-wave radar 10 is obtained based on the point set S11, S12, S13, and S14 acquired by the acquisition module 60. A second motion trajectory MT2 of the second target object 40 relative to the second millimeter-wave radar is obtained based on the point set of the second target object 40. If the first motion trajectory MT1 represents a left-to-right motion trajectory relative to the first millimeter-wave radar 10, it is determined that the first millimeter-wave radar 10 is installed on the left side of the vehicle. If the first motion trajectory MT1 represents a right-to-left motion trajectory relative to the first millimeter-wave radar 10, it is determined that the first millimeter-wave radar 10 is installed on the right side of the vehicle. Similarly, if the second motion trajectory MT2 represents a left-to-right motion trajectory relative to the second millimeter-wave radar 20, it is determined that the second millimeter-wave radar 20 is installed on the left side of the vehicle. If the second motion trajectory MT2 represents a right-to-left motion trajectory relative to the second millimeter-wave radar 20, it is determined that the second millimeter-wave radar 20 is installed on the right side of the vehicle.

[0043] Figure 6 This is a structural block diagram of a vehicle 1 according to an embodiment of the present invention. The vehicle 1 includes: a first millimeter-wave radar 10 and a second millimeter-wave radar 20, which are symmetrically mounted at the rear of the vehicle 1; and a controller 80, which is communicatively connected to the first millimeter-wave radar 10 and the second millimeter-wave radar 20, respectively, for executing the millimeter-wave radar calibration method described in the above embodiment.

[0044] Those skilled in the art will recognize that the modules, units, and method steps of the various examples described in conjunction with the disclosed embodiments herein can be implemented in electronic hardware, computer software, or a combination of both. To clearly illustrate the interchangeability of electronic hardware and software, the components and steps of the examples have been generally described in terms of functionality in the foregoing description. Whether these functions are implemented in electronic hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can implement the described functions using different methods for each specific application, but such implementations should not be considered beyond the scope of the invention.

[0045] Although the present invention has been described with reference to specific embodiments, those skilled in the art should recognize that the scope of the invention is not limited to the specific combinations of the above-described technical features, but also includes other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the inventive concept. For example, technical solutions formed by substituting the above-described features with (but not limited to) technical features with similar functions disclosed in the present invention.

Claims

1. A calibration method for millimeter-wave radar, used for position identification of a first millimeter-wave radar and a second millimeter-wave radar symmetrically mounted at the rear of a vehicle, characterized in that, include: In the signal transmission step, while the vehicle is traveling in a straight line, the first millimeter-wave radar and the second millimeter-wave radar are controlled to transmit the first radar signal and the second radar signal, respectively. The acquisition step involves obtaining the point sets of the first target object collected by the first millimeter-wave radar at at least two time points, and obtaining the point sets of the second target object collected by the second millimeter-wave radar at at least two time points. The first target object and the second target object are static objects located on opposite sides of the vehicle. The point set of the first target object includes the polar coordinates of the first target object in the coordinate system of the first millimeter-wave radar, and the point set of the second target object includes the polar coordinates of the second target object in the coordinate system of the second millimeter-wave radar. as well as The location identification step involves obtaining a first motion trajectory of the first target object relative to the first millimeter-wave radar based on the point set of the first target object, obtaining a second motion trajectory of the second target object relative to the second millimeter-wave radar based on the point set of the second target object, and identifying whether the first millimeter-wave radar and the second millimeter-wave radar are installed on the left or right side of the vehicle based on the first motion trajectory and the second motion trajectory.

2. The calibration method for millimeter-wave radar as described in claim 1, characterized in that, In the location recognition step, if the first motion trajectory or the second motion trajectory represents a motion trajectory from left to right, then it is determined that the first millimeter-wave radar or the second millimeter-wave radar is installed on the left side of the vehicle; if the first motion trajectory or the second motion trajectory represents a motion trajectory from right to left, then it is determined that the first millimeter-wave radar or the second millimeter-wave radar is installed on the right side of the vehicle.

3. The calibration method for millimeter-wave radar as described in claim 2, characterized in that, Also includes: In the cross-confirmation step, if both the first millimeter-wave radar and the second millimeter-wave radar are identified as being located on the left or right side of the vehicle, information indicating a calibration error is output.

4. The calibration method for millimeter-wave radar as described in any one of claims 1 to 3, characterized in that, The vehicle travels in a straight line at a speed of 30 kph or greater.

5. The calibration method for millimeter-wave radar as described in any one of claims 1 to 3, characterized in that, For the first and second target objects at different locations, the signal transmission step, acquisition step, and position identification step are repeated n times. If the results of the n position identifications are consistent, they are taken as the final identification result. If the results of the n position identifications are inconsistent, a message indicating that a calibration error has occurred is output.

6. A calibration device for millimeter-wave radar, used for position identification of a first millimeter-wave radar and a second millimeter-wave radar installed at the rear of a vehicle, characterized in that, include: The signal transmission module controls the first millimeter-wave radar and the second millimeter-wave radar to transmit the first radar signal and the second radar signal respectively while the vehicle is traveling in a straight line; The acquisition module acquires the point sets of the first target object collected by the first millimeter-wave radar at at least two time points, and acquires the point sets of the second target object collected by the second millimeter-wave radar at at least two time points. The first target object and the second target object are static objects located on both sides of the vehicle. The point set of the first target object includes the polar coordinates of the first target object in the coordinate system of the first millimeter-wave radar, and the point set of the second target object includes the polar coordinates of the second target object in the coordinate system of the second millimeter-wave radar. as well as The location recognition module acquires a first motion trajectory of the first target object relative to the first millimeter-wave radar based on the point set of the first target object, acquires a second motion trajectory of the second target object relative to the second millimeter-wave radar based on the point set of the second target object, and identifies whether the first millimeter-wave radar and the second millimeter-wave radar are installed on the left or right side of the vehicle based on the first motion trajectory and the second motion trajectory.

7. The calibration device for millimeter-wave radar as described in claim 6, characterized in that, In the location recognition module, if the first motion trajectory or the second motion trajectory represents a motion trajectory from left to right, then it is determined that the first millimeter-wave radar or the second millimeter-wave radar is installed on the left side of the vehicle; if the first motion trajectory or the second motion trajectory represents a motion trajectory from right to left, then it is determined that the first millimeter-wave radar or the second millimeter-wave radar is installed on the right side of the vehicle.

8. A vehicle, characterized in that, include: A first millimeter-wave radar and a second millimeter-wave radar are symmetrically mounted at the rear of the vehicle. as well as A controller, which is communicatively connected to the first millimeter-wave radar and the second millimeter-wave radar respectively, is used to execute the calibration method of the millimeter-wave radar according to any one of claims 1 to 5.

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