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: a signal emission step of controlling the first millimeter wave radar and the second millimeter wave radar to respectively emit a first radar signal and a second radar signal; a echo acquisition step of acquiring a first echo signal of a first target object and a second echo signal of a second target object; and a position identification step of identifying the positions of the first millimeter wave radar and the second millimeter wave radar based on the first echo signal and the second echo signal, wherein the first target object and the second target object are symmetrically arranged at the left and right rear of the vehicle relative to the center axis of the vehicle, and are not located in the antenna normal direction of the first millimeter wave radar and the second millimeter wave radar. 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 radar calibration method, a 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 radar in a low-cost and convenient manner.

[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, controlling the first millimeter-wave radar and the second millimeter-wave radar to transmit a first radar signal and a second radar signal respectively; an echo acquisition step, acquiring a first echo signal of a first target and a second echo signal of a second target; and a position identification step, performing position identification of the first millimeter-wave radar and the second millimeter-wave radar based on the first echo signal and the second echo signal, wherein the first target and the second target are symmetrically arranged at the left rear and right rear of the vehicle with respect to the central axis of the vehicle, and the first target and the second target are not located in the antenna normal of the first millimeter-wave radar and the second millimeter-wave radar.

[0005] Preferably, in the location identification step, the first coordinates (x1, y1) of the first target object in the first local coordinate system of the first millimeter-wave radar are obtained based on the first echo signal. The first local coordinate system has the intersection of the antenna normal of the first millimeter-wave radar and the radar mounting surface as the origin and the antenna normal of the first millimeter-wave radar as the x-axis. The second coordinates (x2, y2) of the second target object in the second local coordinate system of the second millimeter-wave radar are obtained based on the second echo signal. The second local coordinate system has the intersection of the antenna normal of the second millimeter-wave radar and the radar mounting surface as the origin and the antenna normal of the second millimeter-wave radar as the x-axis. The location identification of the first millimeter-wave radar and the second millimeter-wave radar is performed based on the first coordinates and the second coordinates.

[0006] Preferably, in the location identification step, the positive or negative values ​​of y1 and y2 are used to identify whether the first millimeter-wave radar and the second millimeter-wave radar are respectively located on the left or right side of the vehicle.

[0007] Preferably, the center of the first target object is located on the extension line of the left profile of the vehicle, and the center of the second target object is located on the extension line of the right profile of the vehicle.

[0008] Preferably, the straight-line distance between the first target and the vehicle is greater than or equal to 0.5 meters and less than or equal to 2.0 meters, and the straight-line distance between the second target and the vehicle is greater than or equal to 0.5 meters and less than or equal to 2.0 meters.

[0009] 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.

[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 first target object and a second target object, the first target object and the second target object being symmetrically arranged at the left rear and right rear of the vehicle with respect to the central axis of the vehicle, and the first target object and the second target object not being located in the antenna normal of the first millimeter-wave radar and the second millimeter-wave radar; a signal transmitting module for controlling the first millimeter-wave radar and the second millimeter-wave radar to transmit a first radar signal and a second radar signal respectively; an echo acquisition module for acquiring a first echo signal of the first target object and a second echo signal of the second target object; and a position identification module for performing position identification of the first millimeter-wave radar and the second millimeter-wave radar based on the first echo signal and the second echo signal.

[0011] Preferably, in the location identification module, the first coordinates (x1, y1) of the first target object in the first local coordinate system of the first millimeter-wave radar are obtained based on the first echo signal. The first local coordinate system has the intersection of the antenna normal of the first millimeter-wave radar and the radar mounting surface as the origin and the antenna normal of the first millimeter-wave radar as the x-axis. The second coordinates (x2, y2) of the second target object in the second local coordinate system of the second millimeter-wave radar are obtained based on the second echo signal. The second local coordinate system has the intersection of the antenna normal of the second millimeter-wave radar and the radar mounting surface as the origin and the antenna normal of the second millimeter-wave radar as the x-axis. The location identification of the first millimeter-wave radar and the second millimeter-wave radar is performed based on the first coordinates (x1, y1) and the second coordinates (x2, y2).

[0012] Preferably, in the location recognition module, the positive or negative values ​​of y1 and y2 are used to identify whether the first millimeter-wave radar and the second millimeter-wave radar are respectively located on the left or 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 location of the radar can be calibrated in a low-cost and simple manner. Attached Figure Description

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

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

[0017] Figure 3 This is a structural block diagram of a radar calibration device according to an embodiment of the present invention.

[0018] Figure 4 This is a structural block diagram of a vehicle according to an embodiment of the present invention. Detailed Implementation

[0019] 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.

[0020] 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.

[0021] 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.

[0022] Figure 1 This is a schematic flowchart of a radar calibration method according to an embodiment of the present invention. Figure 2 This is a schematic diagram of a radar calibration method according to an embodiment of the present invention. Combined with... Figure 1 and Figure 2 An embodiment of the radar calibration method according to the present invention will be described, which is applicable to situations where automobile manufacturers calibrate millimeter-wave radars before vehicles leave the factory.

[0023] like Figure 1 As shown, the radar calibration method involved in this embodiment specifically includes the following steps.

[0024] S101 controls the first millimeter-wave radar 10 and the second millimeter-wave radar 20 to transmit the first radar signal and the second radar signal, respectively.

[0025] 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.

[0026] 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.

[0027] When it is time to start the calibration of the first millimeter-wave radar 10 and the second millimeter-wave radar 20 for position identification, the first millimeter-wave radar 10 and the second millimeter-wave radar 20 are first controlled to transmit the first radar signal and the second radar signal respectively.

[0028] S102, acquire the first echo signal of the first target 30 and the second echo signal of the second target 40.

[0029] like Figure 2 As shown, the first target 30 and the second target 40 are symmetrically positioned to the left and right rear of the vehicle 1 relative to the central axis D of the vehicle 1. Therefore, the first target 30 and the second target 40 are respectively within the detection range of the first millimeter-wave radar 10 and the second millimeter-wave radar 20. Furthermore, in order to accurately identify the positions of the first millimeter-wave radar 10 and the second millimeter-wave radar 20, the first target 30 and the second target 40 are not located within the antenna normals of the first millimeter-wave radar 10 and the second millimeter-wave radar 20.

[0030] The first target 30 and the second target 40 can be electromagnetic wave reflectors made of metal plates. When the electromagnetic waves of the first millimeter-wave radar 10 and the second millimeter-wave radar 20 irradiate the first target 30 and the second target 40, they are reflected, generating strong first echo signals and second echo signals, which are received by the first millimeter-wave radar 10 and the second millimeter-wave radar 20.

[0031] S103. The positions of the first millimeter-wave radar 10 and the second millimeter-wave radar 20 are identified based on the first echo signal and the second echo signal.

[0032] As described above, millimeter-wave radar can obtain the X and Y values ​​of a target relative to the radar's coordinate system by transmitting and receiving electromagnetic wave parameters. That is, based on the first echo signal, the first coordinates (x1, y1) of the first target 30 in the first local coordinate system of the first millimeter-wave radar 10 can be obtained, and based on the second echo signal, the second coordinates (x2, y2) of the second target 40 in the second local coordinate system of the second millimeter-wave radar can be obtained.

[0033] Here, the coordinate system of the first millimeter-wave radar 10 is referred to as the first local coordinate system, and the coordinate system of the second millimeter-wave radar 20 is referred to as the second local coordinate system. In this embodiment, as... Figure 2As shown, the first local coordinate system takes the intersection of the antenna normal of the first millimeter-wave radar 10 and the radar mounting surface as its origin, and the antenna normal of the first millimeter-wave radar 10 as its x-axis. The first local coordinate system adopts the right-hand rule. Similarly, the second local coordinate system takes the intersection of the antenna normal of the second millimeter-wave radar 20 and the radar mounting surface as its origin, and the antenna normal of the second millimeter-wave radar 20 as its x-axis. The second local coordinate system also adopts the right-hand rule.

[0034] In this embodiment, the center of the first target 30 is located on the extension line of the left contour line of the vehicle 1, and the center of the second target 40 is located on the extension line of the right contour line of the vehicle 1. Furthermore, it is preferable that the straight-line distance between the first target 30 and the vehicle 1 is greater than or equal to 0.5 meters and less than or equal to 2.0 meters, and the straight-line distance between the second target 40 and the vehicle 1 is greater than or equal to 0.5 meters and less than or equal to 2.0 meters.

[0035] according to Figure 2 As can be seen, under the definition of this embodiment, the first coordinates (x1, y1) of the first target object 30 are located in the first quadrant of the first local coordinate system, that is, x1 > 0, y1 > 0. The second coordinates (x2, y2) of the second target object 40 are located in the second quadrant of the second local coordinate system, that is, x2 > 0, y2 < 0.

[0036] Therefore, the positions of the first millimeter-wave radar 10 and the second millimeter-wave radar 20 can be identified based on the first and second coordinates. Specifically, the sign of the values ​​of y1 and y2 determines whether the first millimeter-wave radar 10 and the second millimeter-wave radar 20 are located on the left or right side of the vehicle 1. For example, in this embodiment, y1 is greater than 0, indicating that the first millimeter-wave radar 10 is located on the left side of the vehicle 1; y2 is less than 0, indicating that the second millimeter-wave radar 20 is located on the right side of the vehicle 1. At this time, different identification codes can be assigned to the first millimeter-wave radar 10 and the second millimeter-wave radar 20, which can then be used to distinguish between the left and right millimeter-wave radars.

[0037] 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.

[0038] Furthermore, in this embodiment, the local coordinate system of the millimeter-wave radar adopts the right-hand rule, but the present invention is not limited to this; the left-hand rule can also be used. In this case, the first coordinate (x1, y1) of the first target 30 is located in the second quadrant of the first local coordinate system, i.e., x1 > 0, y1 < 0. The second coordinate (x2, y2) of the second target 40 is located in the first quadrant of the second local coordinate system, i.e., x2 > 0, y2 > 0. Therefore, if the Y value of the millimeter-wave radar coordinate system of the target is negative, the millimeter-wave radar is located on the left side of the vehicle; if the Y value of the millimeter-wave radar coordinate system of the target is positive, the millimeter-wave radar is located on the right side of the vehicle.

[0039] Furthermore, in this embodiment, the center of the first target 30 is located on the extension line of the left contour line of the vehicle 1, and the center of the second target 40 is located on the extension line of the right contour line of the vehicle 1. However, the present invention is not limited to this, and the first target 30 and the second target 40 can also be located in other positions. Depending on the location of the first target 30 and the second target 40, the positive or negative Y value of the identification first millimeter-wave radar and the second millimeter-wave radar may also be different depending on whether they are located on the left or right side of the vehicle.

[0040] Figure 3 This is a structural block diagram of a radar calibration device according to an embodiment of the present invention.

[0041] like Figure 3 As shown, the millimeter-wave radar calibration device 100 involved in this embodiment includes: a first target 30 and a second target 40, which are symmetrically arranged at the left rear and right rear of the vehicle 1 with respect to the central axis of the vehicle 1, and the first target 30 and the second target 40 are not located in the antenna normal of the first millimeter-wave radar 10 and the second millimeter-wave radar 20; a signal transmission module 50, which controls the first millimeter-wave radar 10 and the second millimeter-wave radar 20 to transmit a first radar signal and a second radar signal, respectively; an echo acquisition module 60, which acquires the first echo signal of the first target 30 and the second echo signal of the second target 40; and a position identification module 70, which performs position identification of the first millimeter-wave radar 10 and the second millimeter-wave radar 20 based on the first echo signal and the second echo signal.

[0042] In the position recognition module 70, the first coordinates (x1, y1) of the first target object 30 in the first local coordinate system of the first millimeter-wave radar 10 are obtained based on the first echo signal. The first local coordinate system has the intersection of the antenna normal of the first millimeter-wave radar 10 and the radar mounting surface as the origin and the antenna normal of the first millimeter-wave radar 10 as the x-axis. The second coordinates (x2, y2) of the second target object 40 in the second local coordinate system of the second millimeter-wave radar 20 are obtained based on the second echo signal. The second local coordinate system has the intersection of the antenna normal of the second millimeter-wave radar 20 and the radar mounting surface as the origin and the antenna normal of the second millimeter-wave radar 20 as the x-axis. The position recognition of the first millimeter-wave radar 10 and the second millimeter-wave radar 20 is performed based on the positive and negative Y values ​​of the first coordinates (x1, y1) and the second coordinates (x2, y2), i.e., y1 and y2. That is, the position recognition of the first millimeter-wave radar 10 and the second millimeter-wave radar 20 is determined, i.e., whether the first millimeter-wave radar and the second millimeter-wave radar are respectively located on the left or right side of the vehicle.

[0043] Figure 4 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: The signal transmission step involves controlling the first millimeter-wave radar and the second millimeter-wave radar to transmit the first radar signal and the second radar signal, respectively. The echo acquisition step involves acquiring the first echo signal of the first target and the second echo signal of the second target. as well as The location identification step involves identifying the locations of the first millimeter-wave radar and the second millimeter-wave radar based on the first echo signal and the second echo signal. The first target and the second target are symmetrically positioned relative to the vehicle's central axis at the vehicle's left and right rear sides, respectively, and neither the first target nor the second target is located within the antenna normal of the first millimeter-wave radar or the second millimeter-wave radar. In the location identification step, the first coordinates (x1, y1) of the first target object in the first local coordinate system of the first millimeter-wave radar are obtained based on the first echo signal. This first local coordinate system has its origin at the intersection of the antenna normal of the first millimeter-wave radar and the radar mounting surface, and its x-axis is the antenna normal of the first millimeter-wave radar. Based on the second echo signal, the second coordinates (x2, y2) of the second target object in the second local coordinate system of the second millimeter-wave radar are obtained. This second local coordinate system has its origin at the intersection of the antenna normal of the second millimeter-wave radar and the radar mounting surface, and its x-axis is the antenna normal of the second millimeter-wave radar. The positions of the first millimeter-wave radar and the second millimeter-wave radar are identified based on the first coordinate and the second coordinate. In the location identification step, the positive or negative values ​​of y1 and y2 are used to identify whether the first millimeter-wave radar and the second millimeter-wave radar are located on the left or right side of the vehicle, respectively.

2. The calibration method for millimeter-wave radar as described in claim 1, characterized in that, The center of the first target object is located on the extension line of the left profile of the vehicle, and the center of the second target object is located on the extension line of the right profile of the vehicle.

3. The calibration method for millimeter-wave radar as described in claim 1, characterized in that, The straight-line distance between the first target and the vehicle is greater than or equal to 0.5 meters and less than or equal to 2.0 meters. The straight-line distance between the second target and the vehicle is greater than or equal to 0.5 meters and less than or equal to 2.0 meters.

4. The calibration method for millimeter-wave radar as described in claim 1, 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.

5. 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 first target and the second target are symmetrically arranged at the left rear and right rear of the vehicle with respect to the central axis of the vehicle, and the first target and the second target are not located in the antenna normal of the first millimeter-wave radar and the second millimeter-wave radar. 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. The echo acquisition module acquires the first echo signal of the first target and the second echo signal of the second target. as well as The location identification module identifies the locations of the first millimeter-wave radar and the second millimeter-wave radar based on the first echo signal and the second echo signal. In the location identification module, the first coordinates (x1, y1) of the first target object in the first local coordinate system of the first millimeter-wave radar are obtained based on the first echo signal. This first local coordinate system has its origin at the intersection of the antenna normal of the first millimeter-wave radar and the radar mounting surface, and its x-axis is the antenna normal of the first millimeter-wave radar. Based on the second echo signal, the second coordinates (x2, y2) of the second target object in the second local coordinate system of the second millimeter-wave radar are obtained. This second local coordinate system has its origin at the intersection of the antenna normal of the second millimeter-wave radar and the radar mounting surface, and its x-axis is the antenna normal of the second millimeter-wave radar. The positions of the first millimeter-wave radar and the second millimeter-wave radar are identified based on the first coordinates (x1, y1) and the second coordinates (x2, y2). In the location recognition module, the positive or negative values ​​of y1 and y2 are used to identify whether the first millimeter-wave radar and the second millimeter-wave radar are located on the left or right side of the vehicle, respectively.

6. 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 4.

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