A millimeter wave radar self-calibration method and device

Abstract

The present application is applicable to the field of millimeter wave radar calibration technology, and provides a self-calibration method and device for a millimeter wave radar, wherein the millimeter wave radar is arranged in a vehicle, and the method comprises: during the driving process of the vehicle, obtaining multiple frames of data detected by the millimeter wave radar and a first driving speed of the vehicle, wherein each frame of the multiple frames of data comprises the Doppler speed of at least one object detected by the millimeter wave radar; determining a target object in a stationary state within the detection range of the millimeter wave radar according to the multiple frames of data; determining a target offset angle of the millimeter wave radar according to the Doppler speed of the target object in the multiple frames of data and the first driving speed of the vehicle. The self-calibration method for the millimeter wave radar provided by the present application can solve the problem of inaccurate calibration of the millimeter wave radar.

Description

Technical Field

[0001] The present application belongs to the technical field of millimeter wave radar calibration, and in particular, relates to a self-calibration method and device for a millimeter wave radar. Background Art

[0002] In autonomous driving systems, sensors are often used to perceive changes in the surrounding environment. Accurate calibration of sensors has become a relatively important part. It can provide more accurate basic data for other modules in the autonomous driving system and ensure the safe and stable operation of the autonomous driving system.

[0003] Since millimeter-wave radar has the characteristics of long coverage distance, not being affected by environmental factors such as weather, and being able to work all day and all weather, it has become a commonly used sensor in autonomous driving systems. In the prior art, there are usually two methods for calibrating millimeter-wave radar. One method is to calibrate the millimeter-wave radar in conjunction with other sensors, such as using a camera to calibrate the millimeter-wave radar. This method is easily affected by manual installation operations and the installation accuracy of the millimeter-wave radar on the vehicle, resulting in errors in the calibration of the millimeter-wave radar. The other method is to calibrate the millimeter-wave radar using multiple corner reflectors. This method requires manual measurement of the distance from multiple corner reflectors to the vehicle. If the manual measurement is inaccurate, it will reduce the accuracy of the millimeter-wave radar calibration. Summary of the invention

[0004] The embodiments of the present application provide a self-calibration method and device for a millimeter-wave radar, which can solve the problem of inaccurate calibration of the millimeter-wave radar.

[0005] In a first aspect, an embodiment of the present application provides a self-calibration method for a millimeter-wave radar, wherein the millimeter-wave radar is arranged on a vehicle, and the method comprises: during the driving process of the vehicle, obtaining a plurality of frames of data detected by the millimeter-wave radar and a first driving speed of the vehicle, wherein each frame of the plurality of frames of data comprises a Doppler velocity of at least one object detected by the millimeter-wave radar; determining a target object that is stationary within a detection range of the millimeter-wave radar according to the plurality of frames of data; and determining a target offset angle of the millimeter-wave radar according to the Doppler velocity of the target object in the plurality of frames of data and the first driving speed of the vehicle.

[0006] In a possible implementation manner of the first aspect, each frame of data further includes an angle of each object of at least one object in a coordinate system of the millimeter wave radar; and determining a stationary target object within a detection range of the millimeter wave radar according to the multiple frames of data includes:

[0007] Determine the target angle range according to the angle of an object in the detection range of the millimeter wave radar, in which the difference between the Doppler velocity detected by the millimeter wave radar and the first driving speed of the corresponding vehicle meets the preset threshold range;

[0008] The target object is determined within the target angle range, and the Doppler velocity of the target object is obtained.

[0009] In a possible implementation of the first aspect, the preset threshold range includes a first preset threshold range and a second preset threshold range; according to the angle of an object in the millimeter wave radar detection range where the difference between the Doppler velocity detected by the millimeter wave radar and the corresponding vehicle's driving speed satisfies the preset threshold range, the target angle range is determined, including: determining the first angle range according to the angle of each object in the coordinate system of the millimeter wave radar in at least one object; dividing the first angle range into multiple angle intervals; in each angle interval, determining the second angle range according to the angle of the object in the first preset threshold range where the difference between the Doppler velocity detected by the millimeter wave radar and the corresponding vehicle's first driving speed satisfies the first preset threshold range, and in multiple second angle ranges, determining the target angle range according to the angle of the object in the second preset threshold range where the difference between the Doppler velocity detected by the millimeter wave radar and the corresponding vehicle's driving speed satisfies the second preset threshold range.

[0010] In a possible implementation manner of the first aspect, determining the target object within the target angle range includes: acquiring first data of any frame in multiple frames of data, where the first data includes a Doppler velocity of at least one candidate object located in the target angle range, an angle of the at least one candidate object in a coordinate system of a millimeter wave radar, and a second driving speed of the vehicle;

[0011] Determine the predicted speed of the vehicle corresponding to each candidate object according to the Doppler speed of each candidate object and the angle in the coordinate system of the millimeter wave radar, as well as the size of the target angle range;

[0012] Determine, among at least one candidate object, a candidate object for which the difference between the second driving speed of the corresponding vehicle and the predicted driving speed of the vehicle is less than a preset threshold as the first object;

[0013] Acquire second data of two adjacent frames of the multi-frame data, the second data also including a travel distance of the vehicle from a first moment to a second moment, a first distance between the vehicle and a first object at the first moment, and a second distance between the vehicle and the first object at the second moment, the first moment being a time point corresponding to a previous frame of data in the two adjacent frames, and the second moment being a time point corresponding to a later frame of data in the two adjacent frames;

[0014] A target object is determined from the determined at least one first object according to the two frames of second data.

[0015] In a possible implementation of the first aspect, determining a target object within a target angle range includes: acquiring first data of any frame in multiple frames of data, the first data including a Doppler velocity of at least one candidate object located within the target angle range, an angle of at least one candidate object in a coordinate system of a millimeter-wave radar, and a second driving speed of a vehicle; determining a predicted driving speed of a vehicle corresponding to each candidate object according to the Doppler velocity and the angle of each candidate object in the coordinate system of the millimeter-wave radar, and the size of the target angle range; and determining, as a target object, a candidate object among at least one candidate object, for which the difference between the second driving speed of the corresponding vehicle and the predicted driving speed of the vehicle is less than a preset threshold.

[0016] In a possible implementation manner of the first aspect, determining the target object within a target angle range includes:

[0017] Acquire second data of two adjacent frames in the multi-frame data, the second data further comprising a travel distance of the vehicle from a first moment to a second moment, a first distance between the vehicle and at least one candidate object in the target angle range at the first moment, and a second distance between the vehicle and at least one candidate object in the target angle range at the second moment, the first moment being a time point corresponding to a previous frame of data in the two adjacent frames, and the second moment being a time point corresponding to a later frame of data in the two adjacent frames;

[0018] A target object is determined from at least one candidate object located in the target angle range according to the two frames of second data.

[0019] In a possible implementation of the first aspect, a target offset angle of a millimeter-wave radar is determined according to a Doppler velocity of a target object in multiple frames of data and a first driving speed of a vehicle, including: obtaining a least squares fitting curve according to the Doppler velocity of the target object in the multiple frames of data and the first speed of the vehicle; and determining the target offset angle of the millimeter-wave radar according to the least squares fitting curve.

[0020] In a second aspect, an embodiment of the present application provides a self-calibration device for a millimeter wave radar, wherein the millimeter wave radar is disposed on a vehicle, and includes:

[0021] An acquisition unit, used to acquire multiple frames of data detected by the millimeter wave radar during the driving process of the vehicle, each frame of the multiple frames of data including a Doppler velocity of at least one object detected by the millimeter wave radar and a first driving speed of the vehicle;

[0022] A first determination unit is used to determine a target object in a stationary state within a detection range of the millimeter wave radar according to the multiple frames of data;

[0023] The second determination unit is used to determine the target offset angle of the millimeter wave radar according to the Doppler velocity of the target object in the multiple frames of data and the first driving speed of the vehicle.

[0024] In a third aspect, an embodiment of the present application provides a terminal device, comprising: a processor and a memory, the memory being used to store a computer program, the processor being used to call and run the computer program from the memory, so that the device executes the method described in the first aspect and any optional method of the first aspect.

[0025] In a fourth aspect, an embodiment of the present application provides a computer-readable storage medium, which stores a computer program. When the computer program is executed by a processor, it implements the method described in the first aspect or any optional method of the first aspect.

[0026] In a fifth aspect, an embodiment of the present application provides a computer program product, which, when executed on a terminal device, enables the terminal device to execute the method described in the first aspect or any optional method of the first aspect.

[0027] Compared with the prior art, the embodiments of the present invention have the following beneficial effects:

[0028] A self-calibration method for a millimeter-wave radar is provided in an embodiment of the present application. The method is based on the principle that the speed of an object at rest directly in front of a vehicle is close to the speed of the vehicle during driving. The data detected by the millimeter-wave radar is used to determine the target object at rest. Then, the millimeter-wave radar is calibrated according to the Doppler speed of the target object and the driving speed of the vehicle. The method is not affected by problems such as manual installation accuracy and collision and extrusion during actual use. The method can execute the self-calibration of the millimeter-wave radar according to actual needs during vehicle driving, correct the target offset angle of the millimeter-wave radar, and improve the accuracy of the self-calibration of the millimeter-wave radar. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0030] Figure 1 is a schematic diagram of calibrating a millimeter wave radar using a camera provided in an embodiment of the present application;

[0031] Figure 2 is a structural schematic diagram of a corner reflector provided in one embodiment of the present application;

[0032] Figure 3 It is a flowchart of a self-calibration method of a millimeter wave radar provided in one embodiment of the present application;

[0033] Figure 4 is a schematic diagram of an angle of an object provided by an embodiment of the present application;

[0034] Figure 5 is a schematic diagram of angle ranges corresponding to multiple objects provided in an embodiment of the present application;

[0035] Figure 6 is a schematic diagram of decomposing vehicle speed provided by an embodiment of the present application;

[0036] Figure 7 It is a schematic diagram of determining whether a target object is a stationary object provided by an embodiment of the present application;

[0037] Figure 8 It is a schematic diagram of determining whether a target object is a moving object provided by an embodiment of the present application;

[0038] Fig. 9 is a schematic diagram of a least squares fitting curve provided in an embodiment of the present application;

[0039] Fig.10 It is a structural schematic diagram of a self-calibration device for a millimeter-wave radar provided in an embodiment of the present application;

[0040] Fig.11 It is a schematic diagram of the structure of the terminal device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0041] In the following description, specific details such as specific system structures, technologies, etc. are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present application. However, it should be clear to those skilled in the art that the present application may also be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to prevent unnecessary details from obstructing the description of the present application.

[0042] In autonomous driving systems, sensors are often used to perceive changes in the surrounding environment. Accurate calibration of sensors has become a relatively important part. It can provide more accurate basic data for other modules in the autonomous driving system and ensure the safe and stable operation of the autonomous driving system.

[0043] The most widely used sensors include cameras, lidars, and millimeter-wave radars. Among them, cameras are easily affected by factors such as lighting or texture requirements in actual application scenarios, which reduces their ability to perceive the surrounding environment; lidars are easily affected by weather conditions such as haze and rain, which reduces the accuracy of perceiving surrounding environmental information; therefore, millimeter-wave radars, which have a long coverage distance, are not affected by weather factors, and can work around the clock, have become a commonly used sensor in autonomous driving systems. Accurate calibration of millimeter-wave radars has become the basis for the stable operation of autonomous driving systems.

[0044] In the prior art, there are usually two methods for calibrating the millimeter-wave radar. One method is to calibrate the millimeter-wave radar in combination with other sensors; the other method is to calibrate the millimeter-wave radar using multiple corner reflectors.

[0045] For example, Figure 1 FIG. 1 is a schematic diagram of calibrating a millimeter wave radar using a camera according to an embodiment of the present application. Figure 1 , x rw ,y rw 、z rw The coordinate system formed is the coordinate system of the millimeter wave radar, x c ,y c 、z c The coordinate system formed is the camera's coordinate system, x cw ,y cw 、z cw The coordinate system formed is the vehicle's coordinate system, x p ,y p The coordinate system formed is the coordinate system corresponding to the target object to be acquired by the camera. In this method, the installation position of the millimeter-wave radar on the vehicle is required to meet the following conditions: rw and x in the vehicle coordinate system cw The direction is consistent with that of the vehicle body, pointing to the right side; the y rw and y in the vehicle coordinate system cw The direction is consistent with that of the vehicle body; z in the millimeter-wave radar coordinate system rw and z in the vehicle coordinate system cw, pointing to the top of the vehicle body. In this way, the camera and millimeter-wave radar are used to obtain images corresponding to the same target object respectively, and the conversion matrix from the camera coordinate system to the vehicle body coordinate system is determined by combining the camera's internal parameters, external parameters, camera installation height, and camera pitch angle θ. Then, the straight-line distance between the millimeter-wave radar and the vehicle is obtained by manual measurement, and the conversion relationship between the millimeter-wave radar coordinate system and the vehicle coordinate system can be obtained. The conversion matrix from the millimeter-wave radar coordinate system to the camera coordinate system is further determined, thereby realizing the calibration of the millimeter-wave radar. This method requires the millimeter-wave radar to be manually installed on the vehicle, which is easily affected by the manual installation accuracy and cannot accurately obtain the calibration data of the millimeter-wave radar.

[0046] For example, see Figure 2 The structure diagram of a corner reflector provided by an embodiment of the present application is shown. In the process of calibrating the millimeter-wave radar using multiple corner reflectors, multiple corner reflectors need to be placed in front of the vehicle body. First, the distance and angle between the corner reflector and the millimeter-wave radar coordinate system are measured respectively using the millimeter-wave radar to obtain the corresponding point coordinates. Then, the real coordinates of the corner reflector in the vehicle coordinate system are manually measured. For multiple corner reflectors, the minimum reprojection error is obtained based on the measured real coordinates and multiple pairs of point coordinates obtained by the millimeter-wave radar, and the yaw angle yaw between the millimeter-wave radar and the vehicle is calculated, thereby completing the calibration of the millimeter-wave radar. This method requires the use of multiple corner reflectors to set up a specific measurement scene, and requires manual measurement of the real coordinates of multiple corner reflectors in the vehicle coordinate system. If the manual measurement is inaccurate, it will reduce the accuracy of the millimeter-wave radar calibration.

[0047] In addition, in actual use, the actual installation position of the millimeter-wave radar on the vehicle will change with the bumps, squeezing or collisions of the vehicle. If the above two methods are still used to calibrate the millimeter-wave radar, the calibration results will have errors. Therefore, the above two methods cannot update the calibration data of the millimeter-wave radar in time during actual application, which can easily reduce the accuracy of the millimeter-wave radar's perception of the surrounding environment data and affect the driving state of the vehicle under the unmanned driving system.

[0048] In order to solve the above problems, the embodiment of the present application provides a self-calibration method for millimeter-wave radar. During the driving process of the vehicle, the position information of the target object in a stationary state and the driving speed of the vehicle are determined by using the data detected by the millimeter-wave radar to calibrate the millimeter-wave radar. The process of calibrating the millimeter-wave radar in this method is not affected by the accuracy of manual installation and the collision and squeezing of the vehicle during actual use. The self-calibration method of the millimeter-wave radar can be executed according to actual needs during the driving process of the vehicle to correct the target offset angle of the millimeter-wave radar. In addition, since this method does not require manual measurement of data, it can further save labor costs.

[0049] like Figure 3 The flowchart of a self-calibration method of a millimeter-wave radar provided in an embodiment of the present application is shown. The method is applicable to an autonomous driving system, and performs self-calibration on a millimeter-wave radar deployed on a vehicle to obtain relevant data for sensing the surrounding environment; the method can also be applied to other systems where a single sensor is deployed. The method can be applied to the scenario of self-calibration of the millimeter-wave radar during vehicle production; it can also be applied to the scenario of the electronic control unit (Electronic Control Unit, ECU) in the vehicle performing self-calibration of the millimeter-wave radar regularly or irregularly. The present application does not impose any restrictions on the application system and application scenario of the method.

[0050] See also Figure 3 , the self-calibration method of the millimeter wave radar includes:

[0051] S101, during vehicle driving, obtaining multiple frames of data detected by a millimeter wave radar and a first driving speed of the vehicle, wherein each frame of the multiple frames of data includes a Doppler speed of at least one object detected by the millimeter wave radar.

[0052] It should be understood that the data obtained by the millimeter wave radar transmitting a beam detection is a frame of data. For example, the millimeter wave radar transmits a millimeter wave beam every 50 ms to complete a detection, and the data generated is a frame of data.

[0053] It should also be understood that during the driving process of the vehicle, as the position of the vehicle continues to change, the objects detected by the millimeter-wave radar may be diverse and repeated. For example, objects in the surrounding environment include but are not limited to pedestrians, guardrails, buildings or trees, etc. Therefore, the multiple frames of data detected by the millimeter-wave radar may include Doppler velocities corresponding to at least one object.

[0054] In the embodiment of the present application, each frame of data in the multiple frames of data includes the Doppler velocity of at least one object detected by the millimeter wave radar and the angle of each object in the coordinate system of the millimeter wave radar. If the object and the millimeter wave radar are regarded as a point, the angle is the angle between the straight line passing through the corresponding point of the object and the millimeter wave radar and the Y axis in the coordinate system of the millimeter wave radar.

[0055] like Figure 4 For a schematic diagram of the angle provided in the embodiment of the present application, see Figure 4 The Y axis in the middle represents the Y axis in the millimeter wave radar coordinate system, and its direction is parallel to the direction of the vehicle's driving speed; Figure 4 The θ in the figure represents the angle of the object in the coordinate system of the millimeter wave radar.

[0056] In the actual design process, the global positioning system (GPS) can be used to obtain the first driving speed of the vehicle. The first driving speed of the vehicle corresponding to the Doppler speed of the object in the multi-frame data detected by the millimeter-wave radar is obtained by interpolation according to the timestamp of the millimeter-wave radar. For example, assuming that the timestamp of the millimeter-wave radar is divided into 0s, 2s, 4s..., the first driving speed of the vehicle corresponding to the timestamp of the millimeter-wave radar is 0s is v0, and the first driving speed of the vehicle corresponding to the timestamp of the millimeter-wave radar is 2s is v1, then the first driving speed of the vehicle corresponding to the timestamp of the millimeter-wave radar is 1s can be calculated using the following formula (1).

[0057]

[0058] The above formula (1) is used to obtain the first driving speed of the vehicle corresponding to the time stamp of the millimeter wave radar being 1s.

[0059] S102, determining a stationary target object within a detection range of the millimeter-wave radar according to the multiple frames of data.

[0060] In practice, the speed of the object directly in front of the vehicle is close enough to the vehicle's driving speed at the corresponding moment, so the difference between the Doppler speed detected by the millimeter wave radar and the corresponding first driving speed of the vehicle can be used to indicate the confidence that the object is the object directly in front of the vehicle. Therefore, the target angle range can be determined based on the angle corresponding to the object whose confidence meets the preset range.

[0061] In a possible implementation, the above-mentioned determination of a stationary target object within the detection range of the millimeter-wave radar based on multiple frames of data includes: determining a target angle range based on an angle of an object in the detection range of the millimeter-wave radar where the difference between the Doppler velocity detected by the millimeter-wave radar and the first driving speed of the corresponding vehicle satisfies a preset threshold range; determining the target object within the target angle range to obtain the Doppler velocity of the target object.

[0062] The preset threshold range includes a first preset threshold range and a second preset threshold range. According to the angle of an object in the detection range of the millimeter wave radar, the difference between the Doppler velocity detected by the millimeter wave radar and the first driving speed of the corresponding vehicle satisfies the preset threshold range, and the target angle range is determined, including: determining the first angle range according to the angle of each object in the coordinate system of the millimeter wave radar in at least one object; dividing the first angle range into multiple angle intervals; in each angle interval, determining the second angle range according to the angle of an object in the first preset threshold range according to the difference between the Doppler velocity detected by the millimeter wave radar and the first driving speed of the corresponding vehicle, and determining the target angle range in multiple second angle ranges according to the angle of an object in the second preset threshold range according to the difference between the Doppler velocity detected by the millimeter wave radar and the driving speed of the corresponding vehicle.

[0063] It should be understood that since each frame of data includes the angle of each object among the multiple objects detected by the millimeter-wave radar in the millimeter-wave radar coordinate system, the angle of the object can be obtained to determine the first angle range, avoiding direct processing of all data within the detection range of the millimeter-wave radar, which can reduce the amount of data to be processed and greatly shorten the time for self-calibration of the millimeter-wave radar.

[0064] For example, a millimeter-wave radar is installed on a vehicle windshield. The detection direction of the millimeter-wave radar is the same as the driving direction of the vehicle. The detection range of the millimeter-wave radar is a 180° range corresponding to the driving direction of the vehicle. Assuming that within the 180-degree range, the angle range of multiple objects detected is 90° to 135°, then it can be determined that the first angle range is 90° to 135°.

[0065] According to actual application requirements, in order to speed up data processing, the first angle range may be relatively large, and it is divided into multiple angle intervals. For each angle range, the angle of the object that satisfies the first preset threshold range according to the difference between the Doppler speed detected by the millimeter-wave radar and the first driving speed of the corresponding vehicle is determined as the corresponding second angle range. For each of the multiple angle ranges, the first preset threshold range corresponding to the respective angle range is set to obtain multiple second angle ranges; then, based on the multiple second angle ranges, the angle of the object that satisfies the second preset threshold range according to the difference between the Doppler speed detected by the millimeter-wave radar and the driving speed of the corresponding vehicle is determined as the target angle range.

[0066] The specific number of multiple angle intervals can be determined according to actual applications. For example, assuming that the resolution of the millimeter wave radar is 5°, its detection range is 180°, and the first angle range is 180°, then the first angle range of 180° can be divided into 36 angle intervals, wherein the angle intervals are -5° to 0°, 0° to 5°, etc.

[0067] It should be noted that the values ​​of the first preset threshold range and the second preset threshold range may be different or the same. The specific value range can be designed according to actual application requirements, and this application does not impose any limitation on this.

[0068] In actual application design, since there may be multiple objects in multiple second angle ranges whose difference between the Doppler velocity detected by the millimeter-wave radar and the corresponding vehicle's driving speed satisfies the second preset threshold range, and there are multiple angles corresponding to the multiple objects, the midpoint of the angles corresponding to the multiple objects can be selected as the target angle range. For example, Figure 5 The diagram is a schematic diagram of angles corresponding to multiple objects provided in the embodiment of the present application, see Figure 5 , assuming that the three angle ranges corresponding to the three objects that meet the second preset threshold range are 10°, 20° and 30° respectively, then the angle range of 20° is selected as the target angle range.

[0069] After determining the target angle range, the target object within the target angle range is identified to obtain the Doppler velocity of the target object and the first driving speed of the vehicle to determine the target offset angle of the millimeter wave radar. In an embodiment of the present application, the method of determining the target object in a stationary state within the target angle range includes: determining based on any frame of data in the multiple frames of data detected by the millimeter wave radar, and / or determining based on two adjacent frames of data in the multiple frames of data detected by the millimeter wave radar.

[0070] In one possible implementation, determining a target object within a target angle range includes: acquiring first data of any frame in a plurality of frames of data, the first data including a Doppler velocity of at least one candidate object located within the target angle range, an angle of at least one candidate object in a coordinate system of a millimeter-wave radar, and a second driving speed of a vehicle; determining a predicted driving speed of a vehicle corresponding to each candidate object according to the Doppler velocity and the angle of each candidate object in a coordinate system of a millimeter-wave radar, and the size of the target angle range; determining, among at least one candidate object, a candidate object for which the difference between the second driving speed of the corresponding vehicle and the predicted driving speed of the vehicle is less than a preset threshold as a target object.

[0071] Specifically, the following formula (2) can be used to calculate the estimated driving speed estimated_ve of the vehicle corresponding to each candidate object, assuming that each candidate object within the target angle range is a stationary object:

[0072]

[0073] In the above formula (2), vi[i] represents the Doppler velocity of the candidate object, angle[i] is the angle corresponding to each candidate object in the millimeter wave radar coordinate system, and yaw is the target angle range.

[0074] The Doppler velocity of the candidate object is the radial velocity relative to the millimeter wave radar. It is not difficult to understand that in practical applications, the millimeter wave radar is deployed in the vehicle. Assume that the speed of the vehicle is v vehicle , then see Figure 6 , by the vehicle speed v vehicle By decomposing it, we can get the radial velocity of the candidate object relative to the radar, that is, the Doppler velocity v of the candidate object. i .

[0075] Based on the above formula (2), the difference between the estimated driving speed estimated_ve of the vehicle corresponding to each candidate object and the second driving speed of the vehicle within the target angle range is calculated. If the difference is less than a preset threshold, the object is determined to be a stationary object, that is, a target object.

[0076] In the actual application design of the present application, the preset threshold value is 0.0151. After more than 300 iterations, the preset threshold value is changed to 0.0038 to obtain a stationary target object under a more accurate threshold.

[0077] In another possible implementation, determining a target object within a target angle range includes: acquiring second data of two adjacent frames in a plurality of frames of data, the second data also including a driving distance of a vehicle from a first moment to a second moment, a first distance between the vehicle and at least one candidate object within the target angle range at the first moment, and a second distance between the vehicle and at least one candidate object within the target angle range at the second moment, the first moment being a time point corresponding to a previous frame of data in two adjacent frames, and the second moment being a time point corresponding to a subsequent frame of data in two adjacent frames; determining the target object from at least one candidate object within the target angle range based on the two frames of second data.

[0078] It is worth noting that in the method of determining based on two adjacent frames of data in the multi-frame data detected by the millimeter-wave radar, the multi-frame data can be any two consecutive frames of data in the multi-frame data detected by the millimeter-wave radar, and the multi-frame data can also be a frame of data in the method of determining based on any frame of data in the multi-frame data detected by the millimeter-wave radar, and the next frame of data adjacent to the frame of data. The embodiment of the present application does not impose any limitation on each frame of data in the multi-frame data.

[0079] like Figure 7 FIG. 1 is a schematic diagram of determining whether a target object is a stationary object provided by an embodiment of the present application, see Figure 7 , the direction indicated by the arrow is the driving direction of the vehicle, B1 and B2 represent two position points along the driving direction of the vehicle, and C represents an object in a stationary state. Based on the second data of two adjacent frames in the multi-frame data, the following can be established: Figure 7 For the various angles shown, if the object is in a stationary state, the relationship between the angle values ​​corresponding to the various angles should satisfy the equation shown in the following formula (3):

[0080] α-phi1+β+phi2=180° (3)

[0081] In actual application, the GPS installed on the vehicle can be used to obtain the vehicle's travel distance B1B2, and the millimeter-wave radar can be used to obtain the first distance B1C, the second distance B2C, the angle phi1 and the angle phi2, respectively. The angle phi1 is the angle of the stationary object detected by the millimeter-wave radar at the first moment, and the angle phi2 is the angle of the stationary object detected by the millimeter-wave radar at the second moment, which is angle[i] in formula (2).

[0082] Using the obtained vehicle travel distance B1B2, the first distance B1C and the second distance B2C, the following formula (4) is used to determine: Figure 7 The angles α and β in .

[0083]

[0084] In the above formula (4), a is the second distance B2C, b is the first distance B1C, and c is the vehicle's travel distance B1B2.

[0085] It should be noted that if Figure 8 FIG. 1 is a schematic diagram of determining whether a target object is a moving object provided by an embodiment of the present application, see Figure 8, the direction indicated by the arrow is the driving direction of the vehicle, B1 and B2 represent two position points of the vehicle moving along the driving direction, C1 and C2 represent two position points of the moving object in the process of moving along the direction indicated by the dotted arrow, and the following can be established based on the moving process of the moving object and the vehicle: Figure 8 For the various angles shown, if the object is in motion, the angle values ​​corresponding to the various angles will not satisfy the equation in the above formula (3).

[0086] In the embodiment of the present application, in order to accurately determine the target object in a stationary state, determining the target object within the target angle range includes: acquiring first data of any frame in multiple frames of data, the first data including the Doppler velocity of at least one candidate object located in the target angle range, the angle of at least one candidate object in the coordinate system of the millimeter wave radar, and the second driving speed of the vehicle;

[0087] Determine the predicted speed of the vehicle corresponding to each candidate object according to the Doppler speed of each candidate object and the angle in the coordinate system of the millimeter wave radar, as well as the size of the target angle range;

[0088] Determine, among at least one candidate object, a candidate object for which the difference between the second driving speed of the corresponding vehicle and the predicted driving speed of the vehicle is less than a preset threshold as the first object;

[0089] Acquire second data of two adjacent frames of the multi-frame data, the second data also including a travel distance of the vehicle from a first moment to a second moment, a first distance between the vehicle and a first object at the first moment, and a second distance between the vehicle and the first object at the second moment, the first moment being a time point corresponding to a previous frame of data in the two adjacent frames, and the second moment being a time point corresponding to a later frame of data in the two adjacent frames;

[0090] A target object is determined from the determined at least one first object according to the two frames of second data.

[0091] For details, please refer to the description of the embodiments of determining a target object in a stationary state in the above two optional examples, which will not be repeated here.

[0092] S103, determining a target offset angle of the millimeter wave radar according to the Doppler velocity of the target object in the multiple frames of data and the first driving speed of the vehicle.

[0093] After the target object is determined, the target offset angle of the millimeter-wave radar is further obtained based on the Doppler velocity of the target object in the multi-frame data and the first driving speed of the vehicle, wherein the first driving speed of the vehicle is the driving speed of the vehicle when the Doppler velocity of the target object is detected by the millimeter-wave radar.

[0094] In a possible implementation, a target offset angle of a millimeter-wave radar is determined according to a Doppler velocity of a target object and a first driving speed of a vehicle, including: obtaining a least squares fitting curve according to the Doppler velocity of the target object and the first driving speed of the vehicle in multiple frames of data; and determining the target offset angle according to the least squares fitting curve.

[0095] Specifically, the relationship between the Doppler velocity of the target object in the multi-frame data and the first driving speed of the vehicle can be expressed as the following formula (5):

[0096]

[0097] The least squares fitting curve is determined by the least squares method, such as Fig. 9 FIG. 1 is a schematic diagram of a least squares fitting curve provided in an embodiment of the present application, see Fig. 9 , the horizontal axis represents the angle value of angle[i]+yaw, and the vertical axis represents the ratio between the Doppler velocity of the target object in the multi-frame data and the first driving speed of the vehicle, so that Fig. 9 The sum of the distances between all objects and the least squares fitting curve is the smallest.

[0098] According to the above formula (5), the initial curve function shown in the following formula (6) is set:

[0099] y=ksinx+bcosx (6)

[0100] In formula (6), k and b are coefficients, x represents yaw in the above formula (2), and y represents the ratio between the Doppler velocity of the target object and the first driving velocity of the vehicle.

[0101] Corresponding to the above formula (5) and the above formula (6), we can get formula (7):

[0102]

[0103] It is not difficult to understand that according to the least squares fitting curve, the ratio between the Doppler velocity of the target object and the first driving speed of the vehicle is known, and the angle value of angle[i]+yaw can be obtained. After solving the least squares method, the k and b values ​​can be obtained. The angle value of angle[i] can be obtained by using the following formula (8), and the angle value corresponding to yaw can be further obtained.

[0104]

[0105] Based on the above formula, the target offset angle can be determined according to the Doppler velocity of the target object and the first driving speed of the vehicle, thereby realizing self-calibration of the millimeter wave radar.

[0106] It should be understood that the actual self-calibration process of the millimeter-wave radar is to obtain the calibration parameters of the millimeter-wave radar. The calibration parameters are the six degrees of freedom parameters of the radar in the vehicle coordinate system, where the six degrees of freedom parameters include roll angle roll, pitch angle yaw, yaw angle pitch and xyz. The roll angle, pitch angle and yaw angle are the angle values ​​of rotation around the X-axis, Y-axis and Z-axis respectively in the vehicle coordinate system. The angle of rotation around the X-axis is called the roll angle roll, the angle of rotation around the Y-axis is called the pitch angle yaw, and the angle of rotation around the Z-axis is called the yaw angle pitch.

[0107] Since the millimeter-wave radar is installed in the vehicle, the roll angle roll, yaw angle pitch and xyz in the 6-degree-of-freedom parameters in the vehicle coordinate system are usually taken as 0. Therefore, the self-calibration process of the millimeter-wave radar mainly obtains its pitch angle yaw rotating around the Y axis, that is, the target offset angle.

[0108] Through practical application, the above method is used to perform self-calibration on the millimeter-wave radar, and the calibration accuracy of the millimeter-wave radar can be reduced to within 0.2°.

[0109] A self-calibration method for a millimeter-wave radar is provided in an embodiment of the present application. The method is based on the principle that the speed of an object at rest directly in front of a vehicle is close to the speed of the vehicle during driving. The data detected by the millimeter-wave radar is used to determine the target object at rest. Then, the millimeter-wave radar is calibrated according to the Doppler speed of the target object and the driving speed of the vehicle. The method is not affected by problems such as manual installation accuracy and collision and extrusion during actual use. The method can execute the self-calibration of the millimeter-wave radar according to actual needs during vehicle driving, correct the target offset angle of the millimeter-wave radar, and improve the accuracy of the self-calibration of the millimeter-wave radar.

[0110] In addition, the target offset angle is obtained based on the least squares fitting curve, and the least squares fitting curve minimizes the error between the Doppler velocity of the target object and the estimated driving speed of the vehicle estimated_ve, and further obtains a more accurate target offset angle of the millimeter wave radar. Therefore, the millimeter wave radar self-calibration method provided in the embodiment of the present application can further improve the accuracy of the millimeter wave radar self-calibration.

[0111] It should be understood that the size of the serial numbers of the steps in the above embodiments does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0112] Corresponding to the self-calibration method of a millimeter wave radar described in the above embodiment, Fig.10A structural block diagram of a self-calibration device for a millimeter-wave radar provided in an embodiment of the present application is shown. For ease of explanation, only the parts related to the embodiment of the present application are shown.

[0113] See also Fig.10 The millimeter wave radar self-calibration device 200 includes: an acquisition unit 201, which is used to acquire multiple frames of data detected by the millimeter wave radar and a first driving speed of the vehicle during the driving process of the vehicle, each frame of the multiple frames of data including a Doppler speed of at least one object detected by the millimeter wave radar;

[0114] A first determining unit 202 is used to determine the Doppler velocity of a target object in a stationary state within a detection range of the millimeter wave radar according to the multiple frames of data;

[0115] The second determining unit 203 is used to determine the target offset angle of the millimeter wave radar according to the Doppler velocity of the target object in the multiple frames of data and the first driving speed of the vehicle.

[0116] Optionally, each frame of data also includes the angle of each object in the coordinate system of the millimeter wave radar in at least one object; the first determination unit 202 is also used to: determine the target angle range according to the angle of the object whose difference between the Doppler velocity detected by the millimeter wave radar and the first driving speed of the corresponding vehicle in the millimeter wave radar detection range satisfies the preset threshold range; determine the target object within the target angle range to obtain the Doppler velocity of the target object.

[0117] Optionally, the preset threshold range includes a first preset threshold range and a second preset threshold range; the target angle range is determined according to the angle of an object within the millimeter-wave radar detection range whose difference between the Doppler velocity detected by the millimeter-wave radar and the corresponding vehicle's driving speed satisfies the preset threshold range, including: determining the first angle range according to the angle of each object in the coordinate system of the millimeter-wave radar in at least one object; dividing the first angle range into multiple angle intervals; in each angle interval, determining the second angle range according to the angle of an object within the first preset threshold range whose difference between the Doppler velocity detected by the millimeter-wave radar and the corresponding vehicle's first driving speed satisfies the first preset threshold range, and in multiple second angle ranges, determining the target angle range according to the angle of an object within the second preset threshold range whose difference between the Doppler velocity detected by the millimeter-wave radar and the corresponding vehicle's driving speed satisfies the second preset threshold range.

[0118] Optionally, determining the target object within the target angle range includes: acquiring first data of any frame in the multiple frames of data, the first data including a Doppler velocity of at least one candidate object located within the target angle range, an angle of at least one candidate object in a coordinate system of the millimeter wave radar, and a second driving speed of the vehicle;

[0119] Determine the predicted speed of the vehicle corresponding to each candidate object according to the Doppler speed of each candidate object and the angle in the coordinate system of the millimeter wave radar, as well as the size of the target angle range;

[0120] Determine, among at least one candidate object, a candidate object for which the difference between the second driving speed of the corresponding vehicle and the predicted driving speed of the vehicle is less than a preset threshold as the first object;

[0121] Acquire second data of two adjacent frames in the multi-frame data, the second data also including the travel distance of the vehicle from the first moment to the second moment, the first distance between the vehicle and the first object at the first moment, and the second distance between the vehicle and the first object at the second moment, the first moment being the time point corresponding to the previous frame data of the two adjacent frames, and the second moment being the time point corresponding to the next frame data of the two adjacent frames; determine the target object from at least one determined first object according to the two frames of second data.

[0122] Optionally, determining the target object within the target angle range includes: acquiring first data of any frame in the multiple frames of data, the first data including a Doppler velocity of at least one candidate object located within the target angle range, an angle of at least one candidate object in a coordinate system of the millimeter wave radar, and a second driving speed of the vehicle;

[0123] Determine the predicted speed of the vehicle corresponding to each candidate object according to the Doppler speed of each candidate object and the angle in the coordinate system of the millimeter wave radar, as well as the size of the target angle range;

[0124] Determine that at least one candidate object, for which the difference between the second driving speed of the corresponding vehicle and the predicted driving speed of the vehicle is less than a preset threshold, is a target object.

[0125] Optionally, determining the target object within the target angle range includes: acquiring second data of two adjacent frames in the multi-frame data, the second data also including the driving distance of the vehicle from the first moment to the second moment, the first distance between the vehicle and at least one candidate object in the target angle range at the first moment, and the second distance between the vehicle and at least one candidate object in the target angle range at the second moment, the first moment being the time point corresponding to the previous frame data of the two adjacent frames, and the second moment being the time point corresponding to the next frame data of the two adjacent frames; determining the target object from at least one candidate object located in the target angle range according to the two frames of second data.

[0126] Optionally, the target offset angle of the millimeter wave radar is determined according to the Doppler velocity of the target object in the multi-frame data and the first driving speed of the vehicle, including: obtaining a least squares fitting curve according to the Doppler velocity of the target object in the multi-frame data and the first driving speed of the vehicle; and determining the target offset angle of the millimeter wave radar according to the least squares fitting curve.

[0127] It should be noted that the information interaction, execution process, etc. between the above-mentioned devices / units are based on the same concept as the method embodiment of the present application. Their specific functions and technical effects can be found in the method embodiment part and will not be repeated here.

[0128] Based on the same inventive concept, the embodiment of the present application further provides a terminal device, the terminal device 300 is as follows Fig.11 shown.

[0129] like Fig.11 As shown, the terminal device 300 of this embodiment includes: a processor 301, a memory 302, and a computer program 303 stored in the memory 302 and executable on the processor 301. The computer program 303 can be executed by the processor 301 to generate instructions, and the processor 301 can implement the steps in the above-mentioned various rights authentication method embodiments according to the instructions. Alternatively, when the processor 301 executes the computer program 303, the functions of each module / unit in the above-mentioned device embodiments are implemented.

[0130] Exemplarily, the computer program 303 may be divided into one or more modules / units, one or more modules / units are stored in the memory 302, and are executed by the processor 301 to complete the present application. One or more modules / units may be a series of computer program instruction segments capable of completing specific functions, and the instruction segments are used to describe the execution process of the computer program 303 in the terminal device 300.

[0131] Those skilled in the art will understand that Fig.11 It is only an example of the terminal device 300 and does not constitute a limitation of the terminal device 300. It may include more or fewer components than shown in the figure, or a combination of certain components, or different components. For example, the terminal device 300 may also include input and output devices, network access devices, buses, etc.

[0132] The processor 301 may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor, etc.

[0133] The memory 302 may be an internal storage unit of the terminal device 300, such as a hard disk or memory of the terminal device 300. The memory 302 may also be an external storage device of the terminal device 300, such as a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card (FlashCard), etc. equipped on the terminal device 300. Further, the memory 302 may also include both an internal storage unit of the terminal device 300 and an external storage device. The memory 302 is used to store computer programs and other programs and data required by the terminal device 300. The memory 302 may also be used to temporarily store data that has been output or is to be output.

[0134] The terminal device provided in this embodiment can execute the above method embodiment, and its implementation principle and technical effect are similar, which will not be repeated here.

[0135] An embodiment of the present application also provides a computer-readable storage medium having a computer program stored thereon, and when the computer program is executed by a processor, the method of the above method embodiment is implemented.

[0136] The embodiment of the present application also provides a computer program product, which, when executed on a terminal device, enables the terminal device to implement the method of the above method embodiment.

[0137] If the above-mentioned integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the present application implements all or part of the processes in the above-mentioned embodiment method, which can be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium. When the computer program is executed by the processor, the steps of the above-mentioned method embodiments can be implemented. Among them, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form. The computer-readable storage medium may at least include: any entity or device that can carry the computer program code to the camera / terminal device, a recording medium, a computer memory, a read-only memory (ROM), a random access memory (RAM), an electrical carrier signal, a telecommunication signal, and a software distribution medium. For example, a USB flash drive, a mobile hard disk, a disk or an optical disk.

[0138] References to "one embodiment" or "some embodiments" etc. described in this application mean that a particular feature, structure or characteristic described in conjunction with the embodiment is included in one or more embodiments of the present application. Thus, the phrases "in one embodiment", "in some embodiments", "in some other embodiments", "in some other embodiments", etc. that appear at different places in this specification do not necessarily all refer to the same embodiment, but mean "one or more but not all embodiments", unless otherwise specifically emphasized in other ways. The terms "including", "comprising", "having" and their variations all mean "including but not limited to", unless otherwise specifically emphasized in other ways.

[0139] In the description of this application, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features.

[0140] In addition, in the present application, unless otherwise clearly stipulated and limited, the terms "connection", "connected", etc. should be understood in a broad sense. For example, it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be the internal connection of two elements or the interaction relationship between two elements. Unless otherwise clearly defined, ordinary technicians in this field can understand the specific meanings of the above terms in this application according to the specific circumstances.

[0141] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, a person skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some or all of the technical features thereof may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A self-calibration method for a millimeter wave radar, wherein the millimeter wave radar is arranged in a vehicle, characterized in that: The method comprises: During the driving of the vehicle, a plurality of frames of data detected by the millimeter-wave radar and a first driving speed of the vehicle are acquired, wherein each frame of the plurality of frames of data includes a Doppler velocity of at least one object detected by the millimeter-wave radar and an angle of each of the at least one object in a coordinate system of the millimeter-wave radar; Determine a target object that is stationary within the detection range of the millimeter-wave radar according to the multiple frames of data; Determining a target offset angle of the millimeter-wave radar according to the Doppler velocity of the target object in the multiple frames of data and the first driving speed of the vehicle; The step of determining a stationary target object within the detection range of the millimeter-wave radar according to the multiple frames of data includes: determining a target angle range according to an angle of an object within the detection range of the millimeter-wave radar whose difference between the Doppler velocity detected by the millimeter-wave radar and the corresponding first driving speed of the vehicle satisfies a preset threshold range; determining a target object within the target angle range to obtain a Doppler velocity of the target object; Determining the target object within the target angle range includes: Acquire first data of any frame in the multiple frames of data, wherein the first data includes a Doppler velocity of at least one candidate object located in the target angle range, an angle of the at least one candidate object in the coordinate system of the millimeter wave radar, and a second driving speed of the vehicle; Determine the preset driving speed of the vehicle corresponding to each candidate object according to the Doppler speed of each candidate object and the angle in the coordinate system of the millimeter wave radar, and the size of the target angle range; Determine, among the at least one candidate object, that the candidate object for which the difference between the second driving speed of the vehicle and the predicted driving speed of the vehicle is less than a preset threshold is the first object; Acquire second data of two adjacent frames of the multiple frames of data, wherein the second data further includes a travel distance of the vehicle from a first moment to a second moment, a first distance between the vehicle and the first object at the first moment, and a second distance between the vehicle and the first object at the second moment, wherein the first moment is a time point corresponding to a previous frame of data of the two adjacent frames, and the second moment is a time point corresponding to a later frame of data of the two adjacent frames; determining the target object from at least one of the determined first objects according to the two frames of second data; Alternatively, determining the target object within the target angle range includes: Acquire second data of two adjacent frames in the multiple frames of data, wherein the second data further includes a travel distance of the vehicle from a first moment to a second moment, a first distance between the vehicle and at least one candidate object in the target angle range at the first moment, and a second distance between the vehicle and at least one candidate object in the target angle range at the second moment, wherein the first moment is a time point corresponding to a previous frame of data in the two adjacent frames, and the second moment is a time point corresponding to a later frame of data in the two adjacent frames; The target object is determined from the at least one candidate object located in the target angle range according to the two frames of second data.

2. The method according to claim 1, characterized in that The preset threshold range includes a first preset threshold range and a second preset threshold range; the target angle range is determined according to the angle of an object in the detection range of the millimeter-wave radar, in which the difference between the Doppler velocity detected by the millimeter-wave radar and the corresponding driving speed of the vehicle satisfies the preset threshold range, including: Determine a first angle range according to an angle of each of the at least one object in the coordinate system of the millimeter wave radar; Dividing the first angle range into a plurality of angle intervals; In each of the angle intervals, a second angle range is determined according to the angle of an object whose difference between the Doppler velocity detected by the millimeter wave radar and the corresponding first driving speed of the vehicle satisfies a first preset threshold range, In the plurality of the second angle ranges, the target angle range is determined according to the angle of the object whose difference between the Doppler velocity detected by the millimeter wave radar and the corresponding driving speed of the vehicle satisfies the second preset threshold range.

3. The method according to claim 1, characterized in that Determining the target offset angle of the millimeter wave radar according to the Doppler velocity of the target object in the multiple frames of data and the first driving speed of the vehicle includes: Obtaining a least squares fitting curve according to the Doppler velocity of the target object in the multiple frames of data and the first velocity of the vehicle; The target offset angle of the millimeter wave radar is determined according to the least squares fitting curve.

4. A self-calibration device for a millimeter wave radar, wherein the millimeter wave radar is arranged in a vehicle, characterized in that: include: an acquisition unit, configured to acquire, during the driving process of the vehicle, a plurality of frames of data detected by the millimeter-wave radar, each frame of the plurality of frames of data including a Doppler velocity of at least one object detected by the millimeter-wave radar, a first driving velocity of the vehicle, and an angle of each of the at least one object in a coordinate system of the millimeter-wave radar; A first determining unit, configured to determine a target object in a stationary state within a detection range of the millimeter-wave radar according to the multiple frames of data; a second determining unit, configured to determine a target offset angle of the millimeter wave radar according to the Doppler velocity of the target object in the multiple frames of data and the first driving speed of the vehicle; The step of determining a stationary target object within the detection range of the millimeter-wave radar according to the multiple frames of data includes: determining a target angle range according to an angle of an object within the detection range of the millimeter-wave radar whose difference between the Doppler velocity detected by the millimeter-wave radar and the corresponding first driving speed of the vehicle satisfies a preset threshold range; determining a target object within the target angle range to obtain a Doppler velocity of the target object; Determining the target object within the target angle range includes: Acquire first data of any frame in the multiple frames of data, wherein the first data includes a Doppler velocity of at least one candidate object located in the target angle range, an angle of the at least one candidate object in the coordinate system of the millimeter wave radar, and a second driving speed of the vehicle; Determine the preset driving speed of the vehicle corresponding to each candidate object according to the Doppler speed of each candidate object and the angle in the coordinate system of the millimeter wave radar, and the size of the target angle range; Determine, among the at least one candidate object, that the candidate object for which the difference between the second driving speed of the vehicle and the predicted driving speed of the vehicle is less than a preset threshold is the first object; Acquire second data of two adjacent frames of the multiple frames of data, wherein the second data further includes a travel distance of the vehicle from a first moment to a second moment, a first distance between the vehicle and the first object at the first moment, and a second distance between the vehicle and the first object at the second moment, wherein the first moment is a time point corresponding to a previous frame of data of the two adjacent frames, and the second moment is a time point corresponding to a later frame of data of the two adjacent frames; determining the target object from at least one of the determined first objects according to the two frames of second data; Alternatively, determining the target object within the target angle range includes: Acquire second data of two adjacent frames in the multiple frames of data, wherein the second data further includes a travel distance of the vehicle from a first moment to a second moment, a first distance between the vehicle and at least one candidate object in the target angle range at the first moment, and a second distance between the vehicle and at least one candidate object in the target angle range at the second moment, wherein the first moment is a time point corresponding to a previous frame of data in the two adjacent frames, and the second moment is a time point corresponding to a later frame of data in the two adjacent frames; The target object is determined from the at least one candidate object located in the target angle range according to the two frames of second data.

5. A terminal device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the method according to any one of claims 1 to 3 is implemented.

6. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the method according to any one of claims 1 to 3 is implemented.

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