Wheel diameter correction method, wheel speed coefficient correction method, vehicle and storage medium

Abstract

The invention discloses a wheel diameter correction method, a wheel speed coefficient correction method, a vehicle and a storage medium, and the wheel diameter correction method comprises the steps: obtaining the external parameter data of the vehicle in a driving path, and obtaining the positioning data of a plurality of positioning points based on the external parameter data; based on the positioning data and a first wheel diameter of the vehicle, obtaining first coordinate data of the detection target under the positioning time corresponding to the plurality of positioning points; acquiring second coordinate data belonging to the same detection target from the first coordinate data based on distance differences of all detection targets in all positioning time; and calculating a correction coefficient based on the second coordinate data, and correcting the wheel diameter based on the correction coefficient. According to the wheel diameter correction method, the wheel diameter of the vehicle is directly corrected according to the external parameter data, the wheel diameter correction does not need to be carried out through online signals such as a GPS, the problems of inaccurate wheel diameter correction and the like caused by weak GPS signals can be reduced or avoided, the dependence of wheel diameter correction on the environment is reduced, and the accuracy and reliability of wheel diameter correction are improved.

Description

Technical Field

[0001] The present application relates to the field of automotive electronic technology, and in particular to a wheel diameter correction method, a wheel speed coefficient correction method, a vehicle and a storage medium. Background Art

[0002] Generally speaking, as the vehicle works, the tire pressure will change to a certain extent. At the same time, in an autonomous vehicle, the vehicle's movement speed is calculated based on the pulse signal installed on the wheel to recursively deduce the vehicle's driving trajectory and achieve relative positioning of the vehicle.

[0003] However, changes in tire pressure will change the relative relationship between the pulse and the actual wheel speed. When the tire pressure decreases, the distance between the center point of the wheel and the ground contact point (i.e., the ground contact wheel diameter of the vehicle) will decrease, resulting in a decrease in the accuracy of relative positioning. Existing wheel diameter correction methods usually use GPS to identify the ground contact wheel diameter of the wheel in real time, and use the absolute position of GPS to correct the wheel speed coefficient.

[0004] However, the existing wheel diameter correction method needs to rely on GPS signals when applying GPS for wheel diameter correction, that is, it is necessary to ensure that a good GPS signal is obtained in a relatively open area so that the wheel speed coefficient can be corrected more accurately. However, in special scenarios such as tunnels, forests, and parking lots, the GPS signal is weak and unstable, which may cause the wheel diameter correction method based on GPS to fail or reduce its accuracy. Summary of the invention

[0005] In order to solve the above technical problems, the present application provides a wheel diameter correction method, a wheel speed coefficient correction method, a vehicle and a storage medium.

[0006] To solve the above problems, the present application provides a first technical solution: a method for correcting the wheel diameter of a vehicle is provided, comprising: obtaining external parameter data of the above-mentioned vehicle on a driving path, and obtaining positioning data of multiple positioning points based on the above-mentioned external parameter data; based on the above-mentioned positioning data and the first wheel diameter of the above-mentioned vehicle, obtaining first coordinate data of the detection target at the positioning time corresponding to the above-mentioned multiple positioning points; based on the distance difference of all the above-mentioned detection targets within all the above-mentioned positioning times, obtaining second coordinate data belonging to the same above-mentioned detection target from the above-mentioned first coordinate data; calculating a correction coefficient based on the above-mentioned second coordinate data, and correcting the above-mentioned first wheel diameter based on the above-mentioned correction coefficient.

[0007] Optionally, the above-mentioned external parameter data includes trajectory data of the above-mentioned multiple positioning points, and semantic data when each of the above-mentioned positioning points performs semantic detection; the above-mentioned positioning data of the multiple positioning points based on the above-mentioned external parameter data includes: interpolating the above-mentioned trajectory data of the above-mentioned positioning points based on the detection time of the above-mentioned semantic data to obtain the above-mentioned positioning data.

[0008] Optionally, after the step of interpolating the trajectory data of the positioning point based on the detection time of the semantic data to obtain the positioning data, the wheel diameter correction method further includes: converting the positioning data at all the positioning times to the initial detection time of the semantic data; or, after the step of acquiring the second coordinate data belonging to the same detection target from the first coordinate data based on the distance difference of all the detection targets at all the positioning times, the wheel diameter correction method further includes: converting the second coordinate data at all the positioning times to the initial detection time of the semantic data.

[0009] Optionally, the correction coefficient is calculated based on the second coordinate data to correct the first wheel diameter based on the correction coefficient, including: calculating the objective function between the fluctuation values ​​of all the detection targets at different positioning times and the ground contact wheel diameter of the vehicle based on the second coordinate data of all the detection targets; and solving the objective function to correct the first wheel diameter based on the solution of the objective function.

[0010] Optionally, based on the second coordinate data of all the detection targets, the objective function between all the detection targets and the ground contact wheel diameter of the vehicle at different positioning times is calculated, including: calculating the covariance data of the second coordinate data of the same detection target; and adding the covariance data of all the detection targets to obtain the objective function.

[0011] Optionally, the above-mentioned obtaining, based on the above-mentioned positioning data and the first wheel diameter of the above-mentioned vehicle, the first coordinate data of the detection target at the positioning time corresponding to the above-mentioned multiple positioning points includes: based on the above-mentioned positioning data, obtaining the third coordinate data of the above-mentioned detection target at each of the above-mentioned positioning points, the above-mentioned third coordinate data being the coordinate data in the second coordinate system; based on the above-mentioned first wheel diameter, converting the detection target of the above-mentioned third coordinate data from the above-mentioned second coordinate system to the above-mentioned first coordinate system to obtain the above-mentioned first coordinate data.

[0012] Optionally, the first coordinate data of the positioning point at each positioning time includes the coordinates of a corner point of at least one of the detection targets; the second coordinate data belonging to the same detection target is obtained from the first coordinate data based on the distance difference of all the detection targets in all the positioning times, including: obtaining the first coordinate data of the two positioning times of the first adjacent time; calculating the difference between the corner point coordinates corresponding to the detection targets in the two first coordinate data of the first adjacent time; when the difference indicates that the distance of the corresponding corner point coordinates is less than a preset threshold, and the difference directions of the corresponding corner point coordinates are in the same direction, determining that the two detection targets corresponding to the first adjacent time belong to the same detection target, so as to obtain the associated coordinate data of the first adjacent time; continuing to perform the difference calculation on the first coordinate data of the two positioning times of the second adjacent time and obtain the associated coordinate data of the second adjacent time, until the calculation of the first coordinate data of all adjacent positioning times is completed, so as to obtain the second coordinate data belonging to the same detection target.

[0013] To solve the above-mentioned problem, the present application provides a second technical solution: providing a method for correcting a wheel speed coefficient, comprising: obtaining a corrected first wheel diameter of the vehicle according to the above wheel diameter correction method; correcting the wheel speed coefficient of the above-mentioned vehicle based on the corrected first wheel diameter; and controlling the driving trajectory of the above-mentioned vehicle based on the corrected wheel speed coefficient.

[0014] To solve the above problems, the present application provides a third technical solution: a vehicle is provided, comprising a processor and a memory, the processor being connected to the memory, wherein the memory stores program instructions; the processor is used to execute the program instructions stored in the memory to implement the above method.

[0015] To solve the above problem, the present application provides a fourth technical solution: providing a computer-readable storage medium, the computer-readable storage medium storing program instructions, and the program instructions can be executed by a processor to implement the above method.

[0016] The present application provides a wheel diameter correction method, a wheel speed coefficient correction method, a vehicle and a storage medium, the wheel diameter correction method comprising: obtaining external parameter data of a vehicle under a section of driving path, so as to obtain positioning data of multiple positioning points based on the external parameter data; obtaining first coordinate data of a detection target at the positioning time corresponding to multiple positioning points based on the positioning data and the first wheel diameter of the vehicle; obtaining second coordinate data belonging to the same detection target from the first coordinate data based on the distance difference of all detection targets in all positioning times; calculating a correction coefficient based on the second coordinate data, so as to correct the first wheel diameter based on the correction coefficient. Through the above manner, the method of the present application can directly locate the first coordinate data of the detection target in multiple positioning points according to the external parameter data, so as to obtain second coordinate data belonging to the same detection target based on the first coordinate data, and calculate the correction coefficient of the first wheel diameter, so as to correct the wheel diameter of the vehicle, without the need to correct the wheel diameter through online signals such as GPS, which can reduce or avoid problems such as inaccurate wheel diameter correction due to weak GPS signals, reduce the dependence of wheel diameter correction on the environment, and thus improve the accuracy and reliability of wheel speed calculation. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. 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 creative work. Among them:

[0018] Figure 1 It is a flowchart of a first embodiment of the wheel diameter correction method provided by the present application;

[0019] Figure 2 is a flow chart of a second embodiment of the wheel diameter correction method provided by the present application;

[0020] Figure 3 is a flow chart of a third embodiment of the wheel diameter correction method provided by the present application;

[0021] Figure 4 is a flow chart of a fourth embodiment of the wheel diameter correction method provided by the present application;

[0022] Figure 5 It is a flow chart of an embodiment of the wheel speed correction method provided by the present application;

[0023] Figure 6 It is a structural schematic diagram of an embodiment of a vehicle provided by the present application;

[0024] Figure 7 It is a structural schematic diagram of an embodiment of a computer-readable storage medium provided by the present application. DETAILED DESCRIPTION

[0025] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0026] It should be noted that if the embodiments of the present application involve directional indications (such as up, down, left, right, front, back...), the directional indications are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0027] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present application, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or suggesting their 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. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by this application.

[0028] The embodiment of the present application first provides a vehicle wheel diameter correction method, which is used to correct the ground contact wheel diameter of the wheel so that the corrected ground contact wheel diameter can be close to the actual wheel diameter, thereby facilitating the subsequent calculation of the vehicle's wheel speed based on the corrected wheel diameter, thereby achieving relative positioning of the vehicle and improving the accuracy of vehicle positioning.

[0029] See also Figure 1 , Figure 1 1 is a flow chart of the first embodiment of the wheel diameter correction method provided by the present application. Figure 1 As shown, in this embodiment, the wheel diameter correction method includes the following steps:

[0030] Step S11: Obtaining external parameter data of the vehicle along a driving path, so as to obtain positioning data of a plurality of positioning points based on the external parameter data.

[0031] Specifically, the external parameter data of a vehicle on a section of a driving path may be, but is not limited to, external position parameters and other related data obtained by external devices such as sensors, lidars, cameras, etc. when the vehicle is traveling on a certain driving path. The external parameter data may be a parameter used to describe the position of the vehicle on the driving path relative to the world coordinate system. After obtaining the external parameter data, the positioning data of multiple positioning points can be obtained based on the external parameter data. Among them, the positioning points can be understood as multiple position trajectory points selected by the vehicle in the section of the driving path. The vehicle has corresponding positioning data in each position trajectory point, and the positioning data is used to describe the relative position relationship between the ground object and the vehicle at a certain positioning point on the driving path.

[0032] Step S12: Based on the positioning data and the first wheel diameter of the vehicle, first coordinate data of the detection target at the positioning time corresponding to the plurality of positioning points is obtained.

[0033] Each positioning point has a corresponding positioning time, and the positioning time is used to describe the time relationship of the positioning point in the driving path. For example, when the driving path includes multiple positioning points, each positioning point has a corresponding positioning time, and the multiple positioning points are arranged in sequence according to the time sequence of the positioning time. The first wheel diameter of the vehicle can be understood as the current wheel diameter determined by the control system of the vehicle. The first wheel diameter can be the wheel diameter under ideal tire pressure, the current wheel diameter defined by the control system, or the wheel diameter after wheel diameter correction in the previous stage, which is not specifically limited here.

[0034] Specifically, after obtaining the positioning data and the first wheel diameter of the vehicle, the positional relationship of a ground object relative to the vehicle at each positioning point can be calculated based on the positioning data of all positioning points and the first wheel diameter of the vehicle. In order to enhance the accuracy of the wheel diameter correction method of this embodiment in a certain application scenario, this embodiment can set a detection target, and the detection target can be a common object in different application scenarios. For example, when a vehicle enters a parking lot or other location, a parking space corner point, a vehicle blocking column, a positioning rod for entering and exiting a gate, etc. can be set as a detection target, so as to obtain the coordinate data of a detection target at the corresponding positioning time based on the positioning data of all positioning points, that is, the first coordinate data. It can be understood that the positioning data corresponding to each positioning point may include one or more detection targets, or may not have a corresponding detection target.

[0035] Step S13: based on the distance difference of all detection targets within all positioning times, second coordinate data belonging to the same detection target is obtained from the first coordinate data.

[0036] After obtaining the first coordinate data of a detection target at the positioning time corresponding to each positioning point, the distance between each detection target can be calculated for the first coordinate data of all detection targets in all positioning times to obtain the distance difference of all detection targets. Based on the distance difference of all detection targets, the second coordinate data belonging to the same detection target at different positioning times can be determined.

[0037] Exemplarily, the external parameter data under a driving path may include a first positioning point, a second positioning point, and a third positioning point. The first positioning point corresponds to the first positioning time, and the positioning data of the first positioning point includes the first coordinate data of the detection target 1 and the detection target 2; the second positioning point corresponds to the second positioning time, and the positioning data of the second positioning point includes the first coordinate data of the detection target 2 and the detection target 3; the third positioning point corresponds to the third positioning time, and the positioning data of the third positioning point includes the first coordinate data of the detection target 3 and the detection target 1. At this time, by respectively calculating the distance difference between the detection targets at the first positioning time and the second positioning time, the distance difference between the detection targets at the second positioning time and the third positioning time, and the distance difference between the detection targets at the first positioning time and the third positioning time, it can be determined from the above scheme that the first coordinate data of the detection target 1 at the first positioning point corresponds to the first coordinate data of the detection target 1 at the third positioning point, the first coordinate data of the detection target 2 at the first positioning point corresponds to the first coordinate data of the detection target 2 at the second positioning point, and the first coordinate data of the detection target 3 at the second positioning point corresponds to the first coordinate data of the detection target 3 at the third positioning point. Therefore, the coordinate data belonging to the same detection target can be determined from the above content to obtain the second coordinate data.

[0038] Step S14: Calculate a correction coefficient based on the second coordinate data to correct the first wheel diameter based on the correction coefficient.

[0039] After obtaining the second coordinate data belonging to the same detection target in all positioning points, the position change relationship of the same three-dimensional object (i.e., detection target) in the above driving path at different positioning times can be determined based on the second coordinate data, so as to calculate the correction coefficient based on the position change relationship and correct the first wheel diameter based on the correction coefficient. The correction coefficient can be used to ensure that the corrected first wheel diameter can maintain a stable value at different positioning times, so as to reduce the wheel diameter fluctuation caused by factors such as tire pressure, and improve the reliability and stability of wheel diameter correction.

[0040] In an embodiment of the present application, the wheel diameter correction method includes: obtaining external parameter data of the vehicle under a section of driving path, so as to obtain positioning data of multiple positioning points based on the external parameter data; obtaining first coordinate data of the detection target at the positioning time corresponding to the multiple positioning points based on the positioning data and the first wheel diameter of the vehicle; obtaining second coordinate data belonging to the same detection target from the first coordinate data based on the distance difference of all detection targets in all positioning times; calculating a correction coefficient based on the second coordinate data, so as to correct the first wheel diameter based on the correction coefficient. In the above manner, the method of this embodiment can directly locate the first coordinate data of the detection target in multiple positioning points according to the external parameter data, so as to obtain the second coordinate data belonging to the same detection target based on the first coordinate data, and calculate the correction coefficient of the first wheel diameter, so as to correct the wheel diameter of the vehicle, without the need to correct the wheel diameter through the GPS signal, which can reduce or avoid the problems such as inaccurate wheel diameter correction caused by weak GPS signal, reduce the dependence of wheel diameter correction on the environment, and thus improve the accuracy and reliability of wheel speed calculation.

[0041] In one embodiment, the external parameter data includes trajectory data of multiple positioning points and semantic data when each positioning point is subjected to semantic detection. Figure 2 , Figure 2 2 is a flow chart of the second embodiment of the wheel diameter correction method provided by the present application. Figure 2 As shown, in this embodiment, the wheel diameter correction method includes the following steps:

[0042] Step S21: Obtaining external parameter data of the vehicle along a driving path, the external parameter data including trajectory data of multiple positioning points and semantic data of each positioning point when performing semantic detection.

[0043] Specifically, the external parameter data of a vehicle on a driving path includes, but is not limited to, trajectory data obtained by collecting parameters through external devices such as sensors, lidars, and image acquisition devices. The external parameter data may also include image data obtained through image acquisition devices set around the vehicle body. For example, the image acquisition devices may be fisheye cameras, industrial cameras, etc. set on both sides of the vehicle body. After obtaining the image data, the semantic information of the image data is instance segmented to obtain voice data. The semantic data may include the detection time when the semantic data is semantically segmented, and the pixel coordinates of the segmentation in the image data. Exemplarily, the trajectory data may include path={pose 1 ,pose 2 ,…pose n}; At the detection time ts i At time , the pixel coordinates can be expressed as

[0044] Step S22: performing interpolation calculation on the trajectory data of the positioning point based on the detection time of the semantic data to obtain positioning data.

[0045] The trajectory data of the positioning point is interpolated based on the detection time of the semantic data. Each detection time has a corresponding positioning point. After the trajectory data of the positioning point is interpolated based on the detection time of the semantic data, the trajectory data at each detection time can be obtained, that is, the positioning data of each positioning time mentioned above. Among them, the detection time of the semantic data can be defined as ts i , the detection time of the semantic data corresponds to the positioning time of the positioning point. Based on the detection time of the semantic data, the positioning data can be obtained as follows

[0046] Step S23: Based on the positioning data and the first wheel diameter of the vehicle, first coordinate data of the detection target at the positioning time corresponding to the plurality of positioning points is obtained.

[0047] Step S24: based on the distance difference of all detection targets within all positioning times, second coordinate data belonging to the same detection target is obtained from the first coordinate data.

[0048] Step S25: Calculate a correction coefficient based on the second coordinate data to correct the first wheel diameter based on the correction coefficient.

[0049] Steps S23-S25 are similar to the above steps S12-S14 and will not be described in detail here.

[0050] In an embodiment of the present application, the wheel diameter correction method obtains external parameter data of the vehicle under a section of driving path, the external parameter data includes trajectory data of multiple positioning points and semantic data when each positioning point performs semantic detection, interpolates the trajectory data of the positioning points based on the detection time of the semantic data to obtain positioning data, obtains the first coordinate data of the detection target at the positioning time corresponding to the multiple positioning points based on the positioning data and the first wheel diameter of the vehicle; obtains the second coordinate data belonging to the same detection target from the first coordinate data based on the distance difference of all detection targets in all positioning times; calculates the correction coefficient based on the second coordinate data, and corrects the first wheel diameter based on the correction coefficient. Therefore, the method of this embodiment can realize wheel diameter correction by using semantic data with good stability, without the need to perform wheel diameter correction through GPS signals, can reduce or avoid problems such as inaccurate wheel diameter correction due to weak GPS signals, reduce the dependence of wheel diameter correction on the environment, and thus improve the accuracy and reliability of wheel speed calculation.

[0051] In an optional implementation, after step S22, the wheel diameter correction method further includes: converting positioning data at all positioning times to initial detection time of semantic data.

[0052] Specifically, the trajectory data of all positioning points have corresponding semantic data, and the semantic data has corresponding detection time. After interpolation calculation is performed on the trajectory data of the positioning points and the positioning data is obtained, the positioning data at each corresponding positioning time is obtained, and the positioning data at each positioning time is converted to the initial detection time of the semantic data, that is, the positioning data of all positioning points are expanded at the initial detection time to obtain the positioning data of the positioning points at different times at the initial detection time.

[0053] In another optional implementation, after step S24, the wheel diameter correction method further includes: converting the second coordinate data at all positioning times to the initial detection time of the semantic data.

[0054] Specifically, after obtaining the second coordinate data belonging to the same detection target in all positioning times, the second coordinate data can be converted to the initial detection time of the semantic data, so that the second coordinate data of all positioning points are expanded at the initial detection time, that is, the second coordinate data of the positioning points belonging to the same detection target at different times at the initial detection time are obtained.

[0055] Furthermore, the above step of converting the second coordinate data to the initial detection time of the semantic data can be converted by the following formula:

[0056]

[0057] Among them, ts 1 is the initial detection time, ts i is one of the above positioning times, i=1,2,3,…; for ts i The translation vector when the image acquisition component at time is converted to the initial detection time, For image acquisition in ts 1 The actual translation vector at the initial detection time, For image acquisition in ts i The actual translation vector at time, For image acquisition in ts 1 The actual rotation matrix at the initial detection time, For image acquisition in ts i The actual matrix at time, for ts i The image acquisition piece at time is converted to the rotation matrix at the time of initial detection.

[0058] Through the above method, the wheel diameter correction method of this embodiment can convert the positioning data or the second coordinate data to the initial detection time of the semantic data, so that the data of all positioning points are expanded at the initial detection time, which is convenient for the subsequent fusion of the data of all positioning points to highlight the position change relationship of the same detection target at different positioning times, and then obtain the correction coefficient.

[0059] In one embodiment, see Figure 3 , Figure 3 FIG. 1 is a flow chart of the third embodiment of the wheel diameter correction method provided by the present application. Figure 3 As shown, step S14 or step S25 may further include the following steps:

[0060] Step S31: Based on the second coordinate data of all the detection targets, the objective function between the fluctuation values ​​of all the detection targets at different positioning times and the ground contact wheel diameter of the vehicle is calculated.

[0061] Specifically, after obtaining the second coordinate data belonging to the same detection target, the objective function between the detection targets of all positioning points and the ground contact wheel diameter of the vehicle is calculated based on all the second coordinate data. It can be understood that after obtaining the second coordinate data of all detection targets, the mapping relationship between the pixel position of the detection target in the image data at different positioning times and the actual position of the detection target relative to the vehicle can be obtained based on the second coordinate data, so as to determine the position fluctuation value of the detection target at different positioning times under the current first wheel diameter based on the mapping relationship, so as to obtain the objective function. Among them, the position fluctuation value of the detection target at different positioning times is the fluctuation difference of the coordinate position of the same detection target at multiple positioning times in the driving path.

[0062] Step S32: solving the objective function to modify the first wheel diameter based on the solution value of the objective function.

[0063] Specifically, after obtaining the objective function, the objective function is solved to find the minimum value of the objective function as the solution value. In an ideal state, the wheel diameter of the vehicle remains unchanged, that is, the coordinate position of the same detection target at different positioning times should remain unchanged. However, due to the influence of factors such as tire pressure and road conditions, the coordinate position of the same detection target at different positioning times will fluctuate in actual application scenarios.

[0064] Therefore, this embodiment can calculate the objective function, which is the fluctuation difference of the coordinate position at multiple positioning times in the current first wheel diameter. By solving the objective function, the actual wheel diameter parameters in the driving path can be obtained to obtain the corrected first wheel diameter. In the above manner, the wheel diameter correction method of this embodiment can use external parameter data to identify the actual wheel diameter during driving to achieve wheel diameter correction, which can reduce or avoid problems such as inaccurate wheel diameter correction due to weak GPS signals, reduce the dependence of wheel diameter correction on the environment, and thus improve the accuracy and reliability of wheel speed calculation.

[0065] Optionally, step S31 includes: calculating covariance data of second coordinate data of the same detection target; and adding up the covariance data of all detection targets to obtain a target function.

[0066] Among them, each detection target may include a number of corner points constituting the detection target, that is, the second coordinate data may include the coordinates of the corner points belonging to the same detection target. After obtaining the second coordinate data belonging to the same detection target, the coordinates of the corner points corresponding to each detection target may be aggregated and calculated. Exemplarily, the detection target includes a first corner point and a second corner point. At this time, the first covariance data of the first corner point of the detection target at different positioning times and the second covariance data of the coordinate data of the second corner point may be calculated to obtain the covariance data corresponding to the detection target.

[0067] After calculating the covariance data of the second coordinate data of the same detection target, the covariance data of all detection targets are summed to obtain the objective function. It can be understood that since there are corresponding covariance data for the corner point coordinates corresponding to the detection target, when summing, the covariance data of different corner points belonging to the same detection target can be summed first, and then the covariance data belonging to different detection targets can be summed to obtain the objective function.

[0068] For example, the objective function can be expressed as follows:

[0069]

[0070] Where N is the number of detected targets, std ij is the covariance data of the jth corner point of the i-th detected target.

[0071] In an embodiment of the present application, the wheel diameter correction method calculates the covariance data of the second coordinate data of the same detection target, adds the covariance data of all detection targets to obtain the objective function, and realizes wheel diameter correction. It can reduce or avoid problems such as inaccurate wheel diameter correction caused by weak GPS signals, reduce the dependence of wheel diameter correction on the environment, and thereby improve the accuracy and reliability of wheel speed calculation.

[0072] In one embodiment, step S12 or step S23 may further include: based on the positioning data, obtaining third coordinate data of the detection target at each positioning point, the third coordinate data being coordinate data in the second coordinate system; based on the first wheel diameter, converting the detection target of the third coordinate data from the second coordinate system to the first coordinate system to obtain the first coordinate data.

[0073] After obtaining the positioning data at the corresponding positioning time, obtain the third coordinate data of the detection target at each positioning point. The third coordinate data can be understood as the coordinate data of the detection target in the second coordinate system, and the second coordinate system can be understood as a body coordinate system set based on a certain position origin on the vehicle. Exemplarily, the second coordinate system can be a coordinate origin set at the back row or trunk position in the car, with the forward direction of the vehicle body as the Y axis, the right direction facing the forward direction of the vehicle body as the X axis, and the vertical upward direction as the Z axis. The first coordinate system can be understood as a relative positioning coordinate system established with the collection site of the external reference data as the origin. After the detection target of the third coordinate data is converted from the second coordinate system to the first coordinate system and the first coordinate data is obtained, it can be convenient to subsequently fuse the data of different positioning points to obtain the second coordinate data belonging to the same detection target.

[0074] Optionally, step S12 or step S23 further includes: based on the positioning data and the first wheel diameter of the vehicle, converting the pixel coordinates of the detection target of each positioning point into the second coordinate system to obtain third coordinate data in the second coordinate system.

[0075] Specifically, the positioning data includes the pixel coordinates corresponding to the detection target in the image data, and the pixel coordinates are the coordinate point data in the camera coordinate system. When the image acquisition component is set on the body of the vehicle, the installation external parameters of the image acquisition component can be defined as and is a translation vector used to describe the positional relationship of the second coordinate system of the image acquisition component relative to the first coordinate system; is a rotation matrix used to describe the rotation relationship between the second coordinate system of the image acquisition component and the first coordinate system. c Convert to the coordinate p in the second coordinate system b , the conversion formula is as follows:

[0076]

[0077] When the origin of the second coordinate system is set at the projection of the rear axle of the vehicle on the ground, the external parameter from the image acquisition component to the ground coordinate system needs to add the distance from the center of the rear axle of the actual vehicle to the ground to the translation amount, that is, the ground contact radius of the vehicle. The formula is as follows:

[0078]

[0079] Where r is the actual contact radius of the vehicle tire, is the translation vector of the image acquisition component. Therefore, combining the above formulas (3) and (4), when the coordinate point in the camera coordinate system is converted to the ground of the vehicle coordinate system, the transformation formula is as follows:

[0080]

[0081] Since in most application scenarios, the detection target is usually on the ground, the semantic data in the above external reference data are all expressed on the ground. For example, when the detection target is a parking space line, it is necessary to detect the parking space line and parking space corner points on the ground. When the pixel coordinates of the semantic detection result on the original image data in the external reference data are (u i ,v i ), the position of the point on the normalized plane of the image corresponding to the pixel coordinate can be calculated based on the intrinsic and extrinsic parameters of the camera. The formula is as follows:

[0082]

[0083] in, is the pixel coordinate (u i ,v i ) is a point on the normalized plane corresponding to , and d is the depth of the point.

[0084] Therefore, the wheel diameter correction method of this embodiment can calculate the above formula (5) and formula (6) according to the current first wheel diameter and positioning data after obtaining the positioning data, so as to map the pixel position obtained in the external reference data to the three-dimensional point on the actual ground. It can be understood that, since the detection target is usually located by identifying the corner point coordinates of each detection target when performing semantic detection on the image data, the coordinate expression of the detection target can be represented by the pixel position of the corner point coordinates. This embodiment can obtain the third coordinate data of the detection target at different positioning times under the current first wheel diameter in the above manner, so as to facilitate the subsequent conversion of the third coordinate data from the second coordinate system to the first coordinate system and obtain the first coordinate data.

[0085] Optionally, see Figure 4 , Figure 4FIG. 4 is a flow chart of the fourth embodiment of the wheel diameter correction method provided by the present application. Figure 4 As shown, the first coordinate data of the positioning point at each positioning time includes the coordinates of the corner point of at least one detection target. Specifically, step S13 or step S24 may include:

[0086] Step S41: Acquire the first coordinate data of two positioning times of the first adjacent time.

[0087] Specifically, the first coordinate data of the above-mentioned multiple positioning points actually have corresponding positioning times, and are arranged in time sequence, so that the first coordinate data of two adjacent positioning times in the time sequence can be obtained. The above-mentioned first adjacent time specifically refers to the first coordinate data of two adjacent positioning times in the first sequence in time sequence. For example, including the first coordinate data of positioning point 1, positioning point 2, positioning point 3 and positioning point 4 arranged in time sequence, the two first coordinate data of the first adjacent time can refer to the first coordinate data of positioning point 1 and positioning point 2, the two first coordinate data of the second adjacent time are the first coordinate data of positioning point 2 and positioning point 3, and the two first coordinate data of the third adjacent time are the first coordinate data of positioning point 3 and positioning point 4.

[0088] Step S42: Calculate the difference between the coordinates of the corner points corresponding to the detection targets in the two first coordinate data within the first adjacent time.

[0089] After obtaining the two first coordinate data of the first adjacent time, the corner point coordinates corresponding to the detection target in the two first coordinate data are calculated by difference, and the specific process of difference calculation is to subtract the corner point coordinates of a detection target in the first coordinate data of positioning point 1 from the corner point coordinates of a detection target in the first coordinate data of positioning point 2. Among them, the above-mentioned detection target can be understood as the relevant markers used to identify scenes, regions and locations during the operation of the vehicle, and the corner point coordinates can be understood as the coordinates of the corner points constituting the detection target in the first coordinate system.

[0090] When the detection target is a parking space, the parking space can usually be composed of four corner point coordinates, and each corner point coordinate of the parking space has its corresponding direction, for example, it can include the upper left, lower left, upper right and lower right corner point coordinates. At this time, the first coordinate data at each positioning time can include one or more detection targets, and the first coordinate data of the first detection target in the first coordinate system can be expressed as The first coordinate data of n detection targets can be expressed as Among them, p 1 is the coordinate of the lower left corner, p 2 is the coordinate of the lower right corner, p 3 is the coordinate of the upper right corner, p 4The coordinates of the upper left corner.

[0091] When calculating the difference in the coordinates of the corner points corresponding to the two detection targets of the two first coordinate data of the first adjacent time, if the first coordinate data includes multiple detection targets, the difference in the coordinates of the corner points can be calculated by selecting a detection target from the first coordinate data of positioning point 1 and selecting a detection target from the first coordinate data of positioning point 2 to combine them, so as to calculate the difference in the coordinates of the corresponding corner points of the two detection targets according to the result of the combination, for example, selecting a detection target from positioning point 1 Select the detection target in positioning point 2 The difference between the corresponding corner points of detection target A and detection target B is calculated, that is, And / or, after determining that a detection target of positioning point 1 and a detection target of positioning point 2 are the same detection target, the detection targets of positioning points 1 and 2 corresponding thereto may be removed from the above combination to reduce repeated calculations and improve the speed of association calculations.

[0092] Step S43: When the distance between the corner point coordinates corresponding to the difference indication is less than a preset threshold and the difference directions of the corresponding corner point coordinates are in the same direction, it is determined that the two detection targets corresponding to the first adjacent time belong to the same detection target to obtain the associated coordinate data of the first adjacent time.

[0093] After obtaining the difference between the corner point coordinates corresponding to the two detection targets, since the difference is the difference between the coordinates, the difference may include a vector distance and a vector direction. If the vector distance of the difference indicates that the distance between the corresponding corner point coordinates is less than a preset threshold, and the vector directions of the four corner point coordinates corresponding to the two detection targets are all in the same direction, it means that the two calculated detection targets correspond to the same detection target on the actual ground, so the corresponding detection targets of two adjacent positioning times can be associated to obtain the associated coordinate data of the first adjacent time.

[0094] Step S44: Continue to perform difference calculation on the first coordinate data of the two positioning times of the second adjacent time and obtain the associated coordinate data of the second adjacent time, until the calculation of the first coordinate data of all adjacent positioning times is completed, so as to obtain the second coordinate data belonging to the same detection target.

[0095] Continue to obtain the first coordinate data of the two positioning times of the second adjacent time, and repeat the above steps S41-S43 to perform difference calculation to obtain the associated coordinate data of the second adjacent time. After calculating the associated coordinate data of the second adjacent time, continue to calculate the associated coordinate data of the third associated time, the fourth associated time, etc., until the first coordinate data of all adjacent positioning times are calculated. After the first coordinate data of all adjacent positioning times are calculated, the associated coordinate data of all adjacent times are information fused to determine which image frames corresponding to which positioning times a certain detection target is observed, and obtain the second coordinate data belonging to the same detection target in all positioning times under the driving path. Among them, the above-mentioned second adjacent time specifically refers to the first coordinate data of the two adjacent positioning times that are located after the sequence of the first adjacent time in time sequence, and the third adjacent time is the first coordinate data of the two adjacent positioning times that are located after the sequence of the second adjacent time, etc., which will not be repeated here.

[0096] In the above manner, the wheel diameter correction method of this embodiment obtains the first coordinate data of the two positioning times of the first adjacent time, calculates the difference of the corner point coordinates corresponding to the detection target in the two first coordinate data in the first adjacent time, and when the difference indicates that the distance of the corresponding corner point coordinates is less than the preset threshold, and the difference direction of the corresponding corner point coordinates is in the same direction, it is determined that the two detection targets corresponding to the first adjacent time belong to the same detection target, so as to obtain the associated coordinate data of the first adjacent time, and continue to perform the difference calculation on the first coordinate data of the two positioning times of the second adjacent time and obtain the associated coordinate data of the second adjacent time, until the calculation of the first coordinate data of all adjacent positioning times is completed, so as to obtain the second coordinate data belonging to the same detection target. Therefore, the position change of a certain three-dimensional object on the actual ground can be obtained from the external parameter data under a section of the driving path, so that the target function between the fluctuation value of all detection targets at different positioning times and the ground contact wheel diameter of the vehicle can be calculated based on the second coordinate data later, and while realizing the wheel diameter correction, it is not necessary to use online signals such as GPS for identification, which can reduce the dependence of the wheel diameter correction on the environment, thereby improving the accuracy and reliability of the wheel speed calculation.

[0097] See also Figure 5 , Figure 5 FIG. 1 is a flow chart of an embodiment of the wheel speed correction method provided by the present application. Figure 5 As shown, the embodiment of the present application also proposes a method for correcting the wheel speed coefficient, and the correction method includes the following steps:

[0098] Step S51: Obtaining a corrected first wheel diameter of the vehicle according to the wheel diameter correction method of any of the above embodiments.

[0099] According to the wheel diameter correction method of the above embodiment, a corrected first wheel diameter can be obtained. Specifically, the correction can be performed through the external parameter data of the vehicle without using online signals such as GPS. This can reduce the dependence of the wheel diameter correction on the environment, thereby improving the accuracy and reliability of the wheel speed calculation.

[0100] Step S52: Based on the corrected first wheel diameter, correct the wheel speed coefficient of the vehicle.

[0101] After obtaining the corrected first wheel diameter, the wheel speed coefficient of the vehicle is corrected based on the corrected first wheel diameter. Specifically, the corrected first wheel diameter can be used as the rolling radius to calculate the wheel circumference, so as to calculate the corresponding wheel speed coefficient according to the actual speed of the vehicle and the wheel circumference of the tire, so as to obtain the corrected wheel speed coefficient.

[0102] Step S53: Control the vehicle's driving trajectory based on the corrected wheel speed coefficient.

[0103] After obtaining the corrected wheel speed coefficient, based on the corrected wheel speed coefficient and external parameter data, the vehicle's driving trajectory can be recursively deduced (Dead Reckoning) using the wheel speed (RPM), the vehicle's inertial measurement unit (IMU), etc., that is, the vehicle's actual ground position can be projected using IPM to achieve relative positioning, which is convenient for subsequent control of the vehicle's driving trajectory and automatic driving.

[0104] Therefore, the wheel speed correction method of this embodiment corrects the wheel speed coefficient of the vehicle based on the corrected first wheel diameter, and controls the driving trajectory of the vehicle based on the corrected wheel speed coefficient, so that the wheel diameter can be identified and corrected using external parameter data under a driving path, and the wheel speed coefficient can be identified by fully utilizing stable internal and external parameter data, thereby eliminating the dependence on GPS, and there is no need to use online signals such as GPS for identification, which reduces the dependence of wheel speed correction on the environment, and ensures the accuracy and reliability of wheel speed calculation in various scenarios.

[0105] See also Figure 6 , Figure 6 Schematic diagram of the structure of an embodiment of the vehicle provided by the present application. Figure 6 As shown, the vehicle 50 of this embodiment includes a memory 52 and a processor 51, and the processor 51 is connected to the memory 52. ​​The memory 52 is used to store program instructions. The processor 51 is used to execute the program instructions stored in the memory 52 to implement the method described in any of the above embodiments.

[0106] The processor 51 may also be referred to as a CPU (Central Processing Unit). The processor 51 may be an integrated circuit chip having the ability to process signals. The processor 51 may also be a general-purpose processor, a digital signaling processor (DSP), an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components. The general-purpose processor may be a microprocessor or the processor may also be any conventional processor, etc.

[0107] The memory 52 can be a memory stick, a TF card, etc., which can store all the information in the vehicle 50, including the input raw data, computer programs, intermediate operation results and final operation results are all stored in the memory. It stores and retrieves information according to the location specified by the controller. With the memory, the string matching prediction device has a memory function and can ensure normal operation. The memory of the string matching prediction device can be divided into main memory (internal memory) and auxiliary memory (external memory) according to its purpose. There is also a classification method of dividing it into external memory and internal memory. External memory is usually a magnetic medium or an optical disk, etc., which can store information for a long time. Memory refers to the storage component on the motherboard, which is used to store the data and programs currently being executed, but is only used to temporarily store programs and data. If the power is turned off or the power is cut off, the data will be lost.

[0108] In the several embodiments provided in the present application, it should be understood that the disclosed methods and devices can be implemented in other ways. For example, the inverter control method described above is only schematic. For example, the division of modules or units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be an indirect coupling or communication connection through some interfaces, devices or units, which can be electrical, mechanical or other forms.

[0109] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the present embodiment.

[0110] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0111] If the 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 technical solution of the present application, or the part that contributes to the prior art, or all or part of the technical solution can be embodied in the form of a software product, which is stored in a storage medium and includes several instructions for a computer device (which can be a personal computer, a system server, or a network device, etc.) or a processor to execute all or part of the steps of the various implementation methods of the present application.

[0112] See also Figure 7 , Figure 7 Schematic diagram of the structure of an embodiment of the computer-readable storage medium provided by the present application. Figure 7 As shown, the computer-readable storage medium of the present application stores program instructions 61 that can implement all the above methods, wherein the program instructions 61 can be stored in the above storage medium in the form of a software product, including several instructions for enabling a computer device (which can be a personal computer, server, or network device, etc.) or a processor to execute all or part of the steps of each implementation method of the present application. The aforementioned storage device includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk and other media that can store program codes, or electronic devices such as computers, servers, mobile phones, tablets, etc.

[0113] The above description is only an implementation method of the present application, and does not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly used in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A method for correcting the wheel diameter of a vehicle, characterized in that: include: Obtaining external parameter data of the vehicle on a driving path, so as to obtain positioning data of a plurality of positioning points based on the external parameter data; Based on the positioning data and the first wheel diameter of the vehicle, obtaining first coordinate data of the detection target at the positioning time corresponding to the plurality of positioning points; Based on the distance difference of all the detection targets within all the positioning times, acquiring second coordinate data belonging to the same detection target from the first coordinate data; A correction coefficient is calculated based on the second coordinate data, so as to correct the first wheel diameter based on the correction coefficient.

2. The wheel diameter correction method according to claim 1, characterized in that: The external parameter data includes trajectory data of the plurality of positioning points and semantic data when each positioning point is subjected to semantic detection; The obtaining positioning data of multiple positioning points based on the external reference data includes: The trajectory data of the positioning point is interpolated based on the detection time of the semantic data to obtain the positioning data.

3. The wheel diameter correction method according to claim 2, characterized in that: After the step of performing interpolation calculation on the trajectory data of the positioning point based on the detection time of the semantic data to obtain the positioning data, the wheel diameter correction method further includes: converting the positioning data at all the positioning times to the initial detection time of the semantic data; or, After the step of acquiring second coordinate data belonging to the same detection target from the first coordinate data based on the distance difference of all the detection targets within all the positioning times, the wheel diameter correction method further includes: All the second coordinate data at the positioning time are converted to the initial detection time of the semantic data.

4. The wheel diameter correction method according to claim 1, characterized in that: The calculating a correction coefficient based on the second coordinate data to correct the first wheel diameter based on the correction coefficient includes: Based on the second coordinate data of all the detection targets, calculating the objective function between the fluctuation values ​​of all the detection targets at different positioning times and the ground contact wheel diameter of the vehicle; The objective function is solved to correct the first wheel diameter based on the solution value of the objective function.

5. The wheel diameter correction method according to claim 4, characterized in that: The step of calculating the objective function between all the detection targets and the ground contact wheel diameter of the vehicle at different positioning times based on the second coordinate data of all the detection targets includes: Calculating covariance data of the second coordinate data of the same detection target; The covariance data of all the detection targets are summed up to obtain the objective function.

6. The wheel diameter correction method according to claim 1, characterized in that: The obtaining, based on the positioning data and the first wheel diameter of the vehicle, first coordinate data of the detected target at the positioning time corresponding to the plurality of positioning points comprises: Based on the positioning data, obtaining third coordinate data of the detection target at each positioning point, wherein the third coordinate data is coordinate data in the second coordinate system; Based on the first wheel diameter, a detection target of the third coordinate data is converted from the second coordinate system to the first coordinate system to obtain the first coordinate data.

7. The wheel diameter correction method according to claim 6, characterized in that: The first coordinate data of the positioning point at each positioning time includes the coordinates of at least one corner point of the detection target; The acquiring second coordinate data belonging to the same detection target from the first coordinate data based on the distance difference of all the detection targets within all the positioning times comprises: Acquire first coordinate data of two positioning times of first adjacent time; Calculate the difference between the corner point coordinates corresponding to the detection target in two of the first coordinate data within the first adjacent time; When the distance between the corner point coordinates corresponding to the difference indication is less than a preset threshold value, and the difference directions of the corresponding corner point coordinates are in the same direction, it is determined that the two detection targets corresponding to the first adjacent time belong to the same detection target, so as to obtain the associated coordinate data of the first adjacent time; Continue to perform difference calculation on the first coordinate data of the two positioning times of the second adjacent time and obtain the associated coordinate data of the second adjacent time until the calculation of the first coordinate data of all adjacent positioning times is completed to obtain the second coordinate data belonging to the same detection target.

8. A method for correcting a wheel speed coefficient, characterized in that: include: Obtaining a corrected first wheel diameter of the vehicle according to the wheel diameter correction method according to any one of claims 1 to 7; Based on the corrected first wheel diameter, correcting the wheel speed coefficient of the vehicle; The driving trajectory of the vehicle is controlled based on the corrected wheel speed coefficient.

9. A vehicle, characterized in that: The method comprises a processor and a memory, wherein the processor is connected to the memory, wherein: The memory stores program instructions; The processor is configured to execute program instructions stored in the memory to implement the method according to any one of claims 1 to 8.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores program instructions, and the program instructions can be executed by a processor to implement the method according to any one of claims 1 to 8.

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