Method and device for calibrating course deflection angle of GNSS antenna and storage medium

Abstract

The invention relates to the technical field of sensor calibration, in particular to a calibration method and device for a course deflection angle of a GNSS antenna and a storage medium. The method comprises the following steps: periodically executing preset steps in the driving process of a vehicle loaded with a GNSS (Global Navigation Satellite System); wherein the presetting step comprises the steps of determining the positioning precision, the course precision and the driving speed corresponding to the current period; judging whether the positioning precision meets the positioning precision condition, the course precision meets the preset course condition and the driving speed is in a preset speed interval or not; if the conditions are met at the same time, calculating the angle of the course deflection angle between the GNSS and the vehicle, and recording the angle of the course deflection angle in an external parameter data set; and when the number of the course deflection angles recorded in the external parameter data set is greater than or equal to a first preset number, determining a calibration result of the course deflection angles according to the first preset number of course deflection angles. The precision of the calibration result can be improved.

Description

Technical Field

[0001] The present disclosure relates to the technical field of sensor calibration, and in particular to a method, device, and storage medium for calibrating the heading angle of a GNSS antenna. Background Art

[0002] Currently, in the field of driver assistance, in order to achieve precise vehicle control, it is necessary to detect the vehicle's track direction. The vehicle's track direction can also be referred to as the vehicle's geometric axis direction or the vehicle's head direction.

[0003] In existing technology, a vehicle's track direction can be determined using Global Navigation Satellite System (GNSS) antennas. For example, GNSS antennas can be installed at the front and rear of the vehicle, and the track direction can be determined by calculating the baseline vector direction between the two GNSS antennas.

[0004] In practice, due to errors in GNSS antenna installation, there is a deviation between the baseline vector direction between the two GNSS antennas and the track direction. For ease of description, this disclosure refers to the baseline vector direction between the two GNSS antennas as the "heading direction," and the angle between the heading direction and the track direction as the "heading angle."

[0005] For example, Figure 1 As shown in the figure, it can be seen that there is a heading angle β between the heading direction and the track direction. Therefore, in order to accurately obtain the track direction of the vehicle, it is necessary to calibrate the heading angle.

[0006] Therefore, how to accurately and conveniently calibrate the heading angle is a problem that needs to be solved at present. Summary of the Invention

[0007] In order to solve the above technical problems, the present disclosure provides a method, device and storage medium for calibrating the heading angle of a GNSS antenna.

[0008] In a first aspect, the present disclosure provides a method for calibrating the heading angle of a GNSS antenna. The method includes: periodically executing preset steps while a vehicle carrying a GNSS is traveling; wherein the preset steps include: determining the positioning accuracy, heading accuracy, and driving speed corresponding to the current period; determining whether the following conditions are simultaneously met: the positioning accuracy meets the positioning accuracy condition, the heading accuracy meets the preset heading condition, and the driving speed is within a preset speed range; if all conditions are met, calculating the heading angle between the GNSS and the vehicle, and recording the heading angle in an external parameter data set; when the number of heading angles recorded in the external parameter data set is greater than or equal to a first preset number, determining a calibration result of the heading angle based on the heading angles recorded in the external parameter data set.

[0009] In some implementations, determining the positioning accuracy corresponding to the current period includes: determining a first distance between a focus of a GNSS positioning error ellipse and a center of the ellipse within the current period; determining whether the following conditions are simultaneously met: the positioning accuracy satisfies a positioning accuracy condition, the heading accuracy satisfies a preset heading condition, and the driving speed is within a preset speed range, including: determining a mobile base station baseline length; and determining a first threshold according to the following formula 1;

[0010] σ_p max =K0(δ a +δ b ×l t ) Formula 1

[0011] Among them, σ_p max represents the first threshold, l t Indicates the baseline length of the mobile base station, K0, δ a and δ b is the default value;

[0012] When the first distance is less than the first threshold, it is determined that the positioning accuracy meets the positioning accuracy condition; when the first distance is greater than or equal to the first threshold, it is determined that the positioning accuracy does not meet the positioning accuracy condition; wherein, the positioning accuracy condition is: the first distance is less than the first threshold.

[0013] In some implementations, determining the baseline length of the mobile base station includes: determining the radius of the circle where the vehicle is located; calculating the ECEF coordinates of the vehicle based on the radius; and determining the baseline length of the mobile base station based on the ECEF coordinates of the vehicle and the ECEF coordinates of the RTK base station.

[0014] In some implementations, determining the heading accuracy corresponding to the current period includes: determining a standard deviation of a second preset number of heading angles; wherein the second preset number of heading angles are: angles between a heading direction detected by GNSS and a preset direction within the second preset number of periods including the current period; and determining whether: the positioning accuracy satisfies a positioning accuracy condition, the heading accuracy satisfies a preset heading condition, and the driving speed is within a preset speed range simultaneously includes: determining a second threshold according to the following formula 2;

[0015]

[0016] Among them, σ_hmax represents the second threshold, K1 and δ c is a preset value, L represents the distance between the phase center points of the dual antennas in GNSS;

[0017] When the standard deviation is less than the second threshold, it is determined that the heading accuracy meets the preset heading condition; when the standard deviation is greater than or equal to the second threshold, it is determined that the heading accuracy does not meet the preset heading condition; wherein the preset heading condition is: the standard deviation of the second preset number of heading angles is less than the second threshold.

[0018] In some implementations, the calibration result of the heading deflection angle is determined based on the heading deflection angle recorded in the external parameter data set, including: dividing the heading deflection angle recorded in the external parameter data set into a third preset number of angle sets, wherein each angle set corresponds to an angle interval of a preset width; determining a fourth preset number of angle sets from the third preset number of angle sets, the number of angles of which is greater than or equal to a third threshold; and determining the calibration result of the heading deflection angle based on the fourth preset number of angle sets.

[0019] In some implementations, the calibration result of the heading deviation angle is determined based on a fourth preset number of angle sets, including: determining, based on the fourth preset number of angle sets, the proportion of the number of angles included in the fourth preset number of angle sets in the first preset number of angles, the median of the angles included in the fourth preset number of angle sets, and the average of the angles included in the fourth preset number of angle sets; when it is determined that the proportion is greater than the fourth threshold and the difference between the median and the average is less than the fifth threshold, the average is used as the calibration result of the heading deviation angle.

[0020] In some implementations, after determining the calibration result of the heading angle according to the first preset number of heading angles, the method further includes: clearing the external parameter data set and periodically executing the preset steps again.

[0021] In a second aspect, a device for calibrating the heading deflection of a GNSS antenna is provided, comprising: an acquisition unit, configured to periodically execute preset steps while a vehicle carrying a GNSS is traveling; wherein the preset steps include: determining the positioning accuracy, heading accuracy, and driving speed corresponding to the current period; judging whether the following conditions are simultaneously satisfied: the positioning accuracy satisfies the positioning accuracy condition, the heading accuracy satisfies the preset heading condition, and the driving speed is within a preset speed range; if all of the conditions are satisfied, calculating the heading deflection angle between the GNSS and the vehicle, and recording the heading deflection angle in an external parameter data set; and a calibration unit, configured to determine a calibration result of the heading deflection angle based on the heading deflection angle recorded in the external parameter data set when the number of heading deflection angles recorded in the external parameter data set is greater than or equal to a first preset number.

[0022] In some implementations, determining the positioning accuracy corresponding to the current period includes: determining a first distance between a focus of a GNSS positioning error ellipse and a center of the ellipse within the current period; determining whether the following conditions are simultaneously met: the positioning accuracy satisfies a positioning accuracy condition, the heading accuracy satisfies a preset heading condition, and the driving speed is within a preset speed range, including: determining a mobile base station baseline length; and determining a first threshold according to the following formula 1;

[0023] σ_p max =K0(δ a +δ b ×l t ) Formula 1

[0024] Among them, σ_p max represents the first threshold, l t Indicates the baseline length of the mobile base station, K0, δ a and δ b is the default value;

[0025] When the first distance is less than the first threshold, it is determined that the positioning accuracy meets the positioning accuracy condition; when the first distance is greater than or equal to the first threshold, it is determined that the positioning accuracy does not meet the positioning accuracy condition; wherein, the positioning accuracy condition is: the first distance is less than the first threshold.

[0026] In some implementations, determining the baseline length of the mobile base station includes: determining the radius of the circle where the vehicle is located; calculating the ECEF coordinates of the vehicle based on the radius; and determining the baseline length of the mobile base station based on the ECEF coordinates of the vehicle and the ECEF coordinates of the RTK base station.

[0027] In some implementations, determining the heading accuracy corresponding to the current period includes: determining a standard deviation of a second preset number of heading angles; wherein the second preset number of heading angles are: angles between a heading direction detected by GNSS and a preset direction within the second preset number of periods including the current period; and determining whether: the positioning accuracy satisfies a positioning accuracy condition, the heading accuracy satisfies a preset heading condition, and the driving speed is within a preset speed range simultaneously includes: determining a second threshold according to the following formula 2;

[0028]

[0029] Among them, σ_hmax represents the second threshold, K1 and δ c is a preset value, L represents the distance between the phase center points of the dual antennas in GNSS;

[0030] When the standard deviation is less than the second threshold, it is determined that the heading accuracy meets the preset heading condition; when the standard deviation is greater than or equal to the second threshold, it is determined that the heading accuracy does not meet the preset heading condition; wherein the preset heading condition is: the standard deviation of the second preset number of heading angles is less than the second threshold.

[0031] In some implementations, a calibration result of the heading deflection angle is determined based on the heading deflection angle recorded in the external parameter data set, including: a calibration unit, specifically used to divide the heading deflection angle recorded in the external parameter data set into a third preset number of angle sets, wherein each angle set corresponds to an angle interval of a preset width; a calibration unit, specifically used to determine a fourth preset number of angle sets from the third preset number of angle sets, the number of angles of which is greater than or equal to a third threshold; and a calibration unit, specifically used to determine the calibration result of the heading deflection angle based on the fourth preset number of angle sets.

[0032] In some implementations, the calibration unit is specifically used to determine the calibration result of the heading deviation angle based on a fourth preset number of angle sets, including: a calibration unit is specifically used to determine, based on the fourth preset number of angle sets, the proportion of the number of angles contained in the fourth preset number of angle sets in the first preset number of angles, the median of the angles contained in the fourth preset number of angle sets, and the average of the angles contained in the fourth preset number of angle sets; the calibration unit is specifically used to use the average as the calibration result of the heading deviation angle when it is determined that the proportion is greater than a fourth threshold and the difference between the median and the average is less than a fifth threshold.

[0033] In some implementations, the calibration device further includes: a circulation unit configured to, after determining a calibration result of the heading angle according to a first preset number of heading angles, clear the external parameter data set and periodically execute the preset steps again.

[0034] In a third aspect, a device for calibrating the heading angle of a GNSS antenna is provided, comprising: a memory and a processor, the memory being used to store a computer program; the processor being used to control the device for calibrating the heading angle of a GNSS antenna to implement the method provided in the first aspect or any implementation of the first aspect when executing the computer program.

[0035] In a fourth aspect, a vehicle is provided, comprising a device for calibrating the heading angle of a GNSS antenna; the device for calibrating the heading angle of a GNSS antenna is used to implement the method provided in the first aspect or any implementation of the first aspect.

[0036] In a fifth aspect, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a computing device, the computing device implements the method provided by the above-mentioned first aspect or any implementation method of the first aspect.

[0037] In a sixth aspect, a computer program product is provided. When the computer program product is run on a computer, the computer implements the method provided by the first aspect or any implementation of the first aspect.

[0038] The technical solution provided by the embodiments of the present disclosure has the following advantages over the prior art:

[0039] The method provided by the present disclosure, on the one hand, takes into account that: during the driving process of a vehicle equipped with GNSS, multiple heading angles calculated in multiple periods can be collected by periodically collecting data, and then the heading angles can be calibrated using the multiple heading angles (for example, the average of the multiple heading angles can be used as the calibration result of the heading angle, etc.). In this way, the error of the heading angle calculated once can be avoided from causing significant interference to the calibration result. For example, when calculating the heading angle once, if the GNSS signal is not good at this time, it may cause a large error in the calculated heading angle. The method of the embodiment of the present disclosure can reduce or even avoid the error of the heading angle calculated once from causing interference to the calibration result.

[0040] On the other hand, it is taken into account that during the driving process of the vehicle, the accuracy of the calculated heading angle varies with the different driving conditions of the vehicle. Specifically, in the embodiment of the present disclosure, it is taken into account that when the positioning accuracy and navigation accuracy are higher, the accuracy of the calculated heading angle is higher; and when the vehicle is traveling within a specific speed range, the accuracy of the calculated heading angle is better than the accuracy of the heading angle calculated when the vehicle is traveling at other speeds. Therefore, in the method provided by the present disclosure, in each acquisition cycle, it is possible to first determine whether the positioning accuracy, heading accuracy and driving speed corresponding to the current cycle simultaneously meet the following conditions: the positioning accuracy meets the positioning accuracy condition, the heading accuracy meets the preset heading condition and the driving speed is within the preset speed range. After determining that all conditions are met, the heading angle is calculated and used as the basis for subsequent calibration of the heading angle. In this way, the accuracy of the calibration result of the heading angle can be further improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present disclosure and, together with the description, serve to explain the principles of the present disclosure.

[0042] In order to more clearly illustrate the embodiments of the present disclosure or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0043] Figure 1 A schematic diagram of the formation of a heading angle;

[0044] Figure 2 A schematic structural diagram of a vehicle provided in an embodiment of the present disclosure;

[0045] Figure 3 This is a flow chart of a method for calibrating the heading angle of a GNSS antenna provided in an embodiment of the present disclosure;

[0046] Figure 4 A second flow chart of a method for calibrating the heading angle of a GNSS antenna provided in an embodiment of the present disclosure;

[0047] Figure 5 A third flow chart of a method for calibrating the heading angle of a GNSS antenna provided in an embodiment of the present disclosure;

[0048] Figure 6 A fourth flow chart of a method for calibrating the heading angle of a GNSS antenna provided in an embodiment of the present disclosure;

[0049] Figure 7 One of the schematic diagrams of a histogram provided in an embodiment of the present disclosure;

[0050] Figure 8 A schematic diagram of a process for determining a calibration result of a heading angle provided in an embodiment of the present disclosure;

[0051] Figure 9 A second schematic diagram of a histogram provided in an embodiment of the present disclosure;

[0052] Figure 10 This is a schematic diagram of a device for calibrating the heading angle of a GNSS antenna according to an embodiment of the present disclosure;

[0053] Figure 11 This is a second structural schematic diagram of a device for calibrating the heading angle of a GNSS antenna provided in an embodiment of the present disclosure. DETAILED DESCRIPTION

[0054] In order to more clearly understand the above-mentioned objectives, features and advantages of the present disclosure, the scheme of the present disclosure will be further described below. It should be noted that the embodiments of the present disclosure and the features therein can be combined with each other in the absence of conflict.

[0055] In the following description, many specific details are set forth to facilitate a full understanding of the present disclosure, but the present disclosure may also be implemented in other ways different from those described herein; it is obvious that the embodiments in the specification are only part of the embodiments of the present disclosure, rather than all of the embodiments.

[0056] First, the relevant technical terms involved in the embodiments of the present disclosure are introduced:

[0057] 1. Heading angle refers to the angle between the heading direction and the track direction. The heading direction can be understood as the baseline vector direction between the two antennas of the Global Navigation Satellite System (GNSS), and the track direction can be understood as the geometric axis direction of the vehicle or the direction of the vehicle's head.

[0058] 2. Mobile base station baseline length refers to the baseline length between the vehicle and the Real-Time Kinematic (RTK) base station.

[0059] 3. The positioning error ellipse refers to an ellipse used to illustrate the distribution range of positioning errors. Specifically, since the positioning system's error covariance matrix is ​​a symmetric matrix, its elements reflect the correlation and variance between errors in different directions. The parameters of the error ellipse can be obtained by performing mathematical operations such as eigenvalue decomposition on the covariance matrix. Specifically, the lengths of the error ellipse's semi-major and semi-minor axes can be determined based on the eigenvalues ​​of the covariance matrix, and the orientation of the ellipse can be determined based on the eigenvectors.

[0060] The following is an introduction to the technical solutions provided by the embodiments of the present disclosure:

[0061] Currently, in traditional calibration methods, the heading angle is usually calculated once in a specific scenario, and the calculated heading angle is used as the calibration result of the heading angle, and the calibration result is continuously used thereafter.

[0062] When using the above calibration method to calibrate the heading angle, on the one hand, the vehicle body may deform during driving, causing the heading angle to dynamically "creep." This can cause the initially calibrated heading angle to gradually become inaccurate. Furthermore, with traditional calibration methods, the accuracy of the calibration results depends on the quality of the GNSS signal during the calibration process. A poor GNSS signal during calibration can lead to inaccurate results.

[0063] In order to solve the above problems, in the embodiments of the present disclosure, on the one hand, it is taken into account that: during the driving process of a vehicle equipped with GNSS, multiple heading deflection angles calculated in multiple periods can be collected by periodically collecting data, and then the heading deflection angles can be calibrated using the multiple heading deflection angles (for example, the average of the multiple heading deflection angles can be used as the calibration result of the heading deflection angle, etc.). In this way, the error of the heading deflection angle calculated once can be avoided from causing significant interference to the calibration result. For example, when calculating the heading deflection angle once, if the GNSS signal is not good at this time, it may cause a large error in the calculated heading deflection angle. The method of the embodiments of the present disclosure can reduce or even avoid the error of the heading deflection angle calculated once from causing interference to the calibration result.

[0064] On the other hand, it is taken into account that during the driving process of the vehicle, the accuracy of the calculated heading angle varies with the different driving conditions of the vehicle. Specifically, in the embodiment of the present disclosure, it is taken into account that when the positioning accuracy and navigation accuracy are higher, the accuracy of the calculated heading angle is higher; and when the vehicle is traveling within a specific speed range, the accuracy of the calculated heading angle is better than the accuracy of the heading angle calculated when the vehicle is traveling at other speeds. Therefore, in the method provided by the present disclosure, in each acquisition cycle, it is possible to first determine whether the positioning accuracy, heading accuracy and driving speed corresponding to the current cycle simultaneously meet the following conditions: the positioning accuracy meets the positioning accuracy condition, the heading accuracy meets the preset heading condition and the driving speed is within the preset speed range. After determining that all conditions are met, the heading angle is calculated and used as the basis for subsequent calibration of the heading angle. In this way, the accuracy of the calibration result of the heading angle can be further improved.

[0065] Based on the above considerations, the present disclosure provides a method, device, and storage medium for calibrating the heading angle of a GNSS antenna. The following describes the specific implementation process of the method for calibrating the heading angle of a GNSS antenna provided by the present disclosure in conjunction with examples.

[0066] First, the application scenarios of the calibration method of the heading angle of the GNSS antenna provided by the embodiment of the present disclosure are introduced:

[0067] The calibration method of the heading angle of the GNSS antenna provided by the embodiment of the present disclosure can be applied to various types of vehicles. Figure 2 FIG2 is a schematic diagram of a vehicle structure provided by the present disclosure. The vehicle 10 may include: an intelligent driving system 11 for implementing functions such as driving navigation and assisted driving; a steering system 12 for controlling vehicle steering; a power braking system 13 for controlling vehicle power output and braking; and a GNSS system 14.

[0068] The intelligent driving system 11 may include: a vehicle controller 111, a vehicle-mounted sensor 112, and a communication module 113, etc.

[0069] The vehicle-mounted sensor 112 is used to detect the driving environment around the vehicle. In actual application, the vehicle-mounted sensor 112 may include a camera, an ultrasonic radar, a millimeter-wave radar, a laser radar, and other components.

[0070] The communication module 113 is used to enable the vehicle 10 to communicate with other vehicles or communication base stations and other devices.

[0071] The vehicle controller 111 is used to control the steering system 12 and the power brake system 13 according to information received from the vehicle-mounted sensor 112, the communication module 113 and the GNSS 14, so as to control the vehicle to travel.

[0072] In actual application, the method for calibrating the heading angle of a GNSS antenna provided in the embodiments of the present disclosure can be applied to a device for calibrating the heading angle of a GNSS antenna (hereinafter referred to as the "calibration device"). In some implementations, the functions of the calibration device can be implemented by a software / hardware module in the vehicle controller 111. In other implementations, the functions of the calibration device can also be implemented by a software / hardware module independent of the vehicle controller 111. The embodiments of the present disclosure do not impose any special restrictions on the specific form of the device for calibrating the heading angle of a GNSS antenna.

[0073] The following describes the calibration method of the heading angle of the GNSS antenna provided by the embodiment of the present disclosure, taking the operation process of the calibration device as an example. Figure 3 As shown, the method may include the following S21-S22:

[0074] S21. While the vehicle equipped with the GNSS is traveling, periodically execute the preset steps.

[0075] The preset steps include the following S211-S213:

[0076] S211. Determine the positioning accuracy, heading accuracy, and driving speed corresponding to the current cycle.

[0077] The positioning accuracy may specifically be the measurement accuracy of positioning information detected using GNSS.

[0078] In addition, the heading accuracy may specifically be the measurement accuracy of the heading direction detected by using GNSS.

[0079] S212: Determine whether the following conditions are met simultaneously: the positioning accuracy meets the positioning accuracy condition, the heading accuracy meets the preset heading condition, and the driving speed is within the preset speed range.

[0080] The maximum and minimum values ​​of the preset speed range can be set according to actual needs.

[0081] S213: If both conditions are met, calculate the heading deflection angle between the GNSS and the vehicle, and record the heading deflection angle in the external parameter data set.

[0082] In some implementations, on the one hand, in the GNSS module, the vehicle positioning result (lat t ,lon t,h t ). Among them, lat t Indicates the latitude of the current period t, lon t Indicates the longitude of the current cycle t, h t represents the height of the current period t. Therefore, the vehicle's track angle T can be calculated using the following formula (1): t :

[0083]

[0084] Among them, lat t-1 Indicates the latitude of the previous period t-1, lon t-1 represents the longitude of the previous cycle t-1. t It can be understood as the angle between the track direction and the preset direction.

[0085] On the other hand, in the GNSS module, the heading angle (i.e. the angle between the heading direction and the preset direction) θ of the current cycle t detected by the GNSS can be obtained through the NMEA-0183HDT statement. t .

[0086] Therefore, by calculating the track angle T t and heading angle θ t The difference between the heading angle Δ between the GNSS and the vehicle corresponding to the current cycle can be obtained. t Specifically, the angle Δ can be calculated according to the following formula (2): t :

[0087] Δ t =T t -θ t Formula (2)

[0088] The following is an implementation method divided into two parts, which respectively introduces in detail the specific implementation process of determining whether the positioning accuracy meets the positioning accuracy condition and determining whether the heading accuracy meets the preset heading condition in S212.

[0089] In the implementation of the first part, on the one hand, it is considered that: in the current cycle, the length of the major semi-axis σ_maj of the GNSS positioning error ellipse can be obtained according to the NMEA-0183GST sentence t and the length of the minor axis σ_min t , so the length of the major axis of the GNSS positioning error ellipse σ_maj can be used t and the length of the minor axis σ_min t , calculate the distance between the focus of the GNSS positioning error ellipse and the center of the ellipse (hereinafter referred to as the first distance), and then use the first distance to reflect the positioning accuracy.

[0090] Therefore, if Figure 4 As shown, in S211, determining the positioning accuracy corresponding to the current cycle may include S211a:

[0091] S211a: Determine a first distance between the focus and the center of the GNSS positioning error ellipse in the current period.

[0092] Specifically, the first distance σ_p can be calculated according to the following formula (3): t :

[0093]

[0094] Among them, σ_maj t and σ_min t The lengths of the major and minor axes of the GNSS positioning error ellipse are respectively, and t represents the current cycle.

[0095] On the other hand, considering that: whether the first distance is less than a threshold (hereinafter referred to as the first threshold) can be used to determine whether the positioning accuracy meets the positioning accuracy condition. Furthermore, considering that the positioning accuracy is affected by the baseline length of the mobile base station, the baseline length of the mobile base station can be used to determine the value of the first threshold.

[0096] Therefore, if Figure 4 As shown, in S212, the process of determining whether the positioning accuracy meets the positioning accuracy condition may include the following S212a1-S212a4:

[0097] S212a1. Determine the baseline length of the mobile base station.

[0098] In some designs, S212a1 may specifically include the following contents of S1-S3:

[0099] S1. Determine the radius of the circle where the vehicle is located.

[0100] Specifically, the radius N of the circle where the vehicle is located can be calculated according to the following formula (4): t :

[0101]

[0102] Among them, a is the semi-major axis constant of the coordinate system reference ellipsoid, e is the first eccentricity of the coordinate system reference ellipsoid, lat t The latitude of the vehicle detected by GNSS in the current period, and t represents the current period.

[0103] Specifically, in the GNSS module, the vehicle positioning result (lat t ,lont ,h t ). Among them, lat t Indicates latitude, lon t Indicates longitude, h t Indicates altitude.

[0104] S2. Calculate the Earth-Centered, Earth-Fixed Coordinate System (ECEF) coordinates of the vehicle based on the radius of the orbital circle where the vehicle is located.

[0105] The ECEF coordinates of the vehicle can be calculated according to the following formula (5):

[0106]

[0107] S3. Determine the baseline length of the mobile base station based on the ECEF coordinates of the vehicle and the ECEF coordinates of the RTK base station.

[0108] The baseline length of the mobile base station can be calculated according to the following formula (6):

[0109]

[0110] in, Indicates the ECEF coordinates of the RTK base station. Specifically, the ECEF coordinates of the RTK base station can be obtained through RTCM-3.x1006 information.

[0111] S212a2. Determine a first threshold according to the following formula (7).

[0112] σ_p max =K0(δ a +δ b ×l t )Formula (7)

[0113] Among them, σ_p max represents the first threshold, l t Indicates the baseline length of the mobile base station, K0, δ a and δ b is the default value.

[0114] In some designs, δ a and δ b The value can be taken as the fixed error and proportional error of the GNSS equipment currently used in the vehicle as specified in the "GB / T39399-2020 General Specification for Beidou Satellite Navigation System Measurement Receivers".

[0115] S212a3, when the first distance σ_p t Less than the first threshold σ_pmax , determine that the positioning accuracy meets the positioning accuracy conditions.

[0116] S212a4, when the first distance σ_p t Greater than or equal to the first threshold σ_p max , determine that the positioning accuracy does not meet the positioning accuracy conditions.

[0117] In other words, the above positioning accuracy conditions are specifically: the first distance σ_p t Less than the first threshold σ_p max .

[0118] In the implementation of the second part, on the one hand, it is considered that the standard deviation of the angle between the heading direction detected by GNSS and the preset direction in multiple cycles can be used to reflect the heading accuracy.

[0119] Therefore, if Figure 5 As shown, in S211, determining the heading accuracy corresponding to the current cycle may include S211b:

[0120] S211b: Determine the standard deviation of a second preset number of heading angles.

[0121] The second preset number of heading angles are: angles between the heading direction detected by GNSS and the preset direction within a second preset number of periods including the current period.

[0122] Specifically, in one design, the standard deviation σ_h of the second preset number of heading angles can be calculated according to the following formula group (8): t :

[0123]

[0124] Wherein, n represents the second preset number, i represents the number of the cycle, for example, i=t represents the current cycle t, and i=tn represents the nth cycle before the current cycle. i represents the heading angle detected by GNSS in period i (i.e., the angle between the heading direction and the preset direction).

[0125] In another design, the standard deviation σ_h of the second preset number of heading angles can be calculated according to the following formula (9): t :

[0126]

[0127] The initial values ​​and can be calculated by the following formula (10):

[0128]

[0129] On the other hand, considering that: whether the above standard deviation is less than a threshold (hereinafter referred to as the second threshold) can be used to determine whether the heading accuracy meets the heading accuracy condition. Furthermore, considering that the heading accuracy is affected by the distance between the phase center points of the two antennas in the GNSS, the distance between the phase center points of the two antennas in the GNSS can be used to determine the value of the first threshold.

[0130] Therefore, if Figure 5 As shown, in S212, the process of determining whether the positioning accuracy meets the positioning accuracy condition may include the following S212b1-S212b3:

[0131] S212b1. Determine the second threshold according to the following formula (11).

[0132]

[0133] Among them, σ_hmax represents the second threshold, K1 and δ c is a preset value, and L represents the distance between the phase center points of the two antennas in GNSS.

[0134] In some designs, δ c It is the dynamic orientation accuracy of the GNSS equipment currently used in vehicles as specified in "BD 420073-2022 Performance Requirements and Test Methods for Global Satellite Navigation System (GNSS) Orientation Equipment".

[0135] S212b2: When the standard deviation of the second preset number of heading angles is less than a second threshold, determine that the heading accuracy meets the preset heading condition.

[0136] S212b3: When the standard deviation of the second preset number of heading angles is greater than or equal to a second threshold, determine that the heading accuracy does not meet the preset heading condition.

[0137] In other words, the above-mentioned preset heading condition includes: the standard deviation of the second preset number of heading angles is less than the second threshold.

[0138] In the case where the heading deflection angle is recorded in the external parameter data set through the above S21, the method further includes:

[0139] S22. When the number of heading deflections recorded in the external parameter data set is greater than or equal to a first preset number, determine a calibration result of the heading deflection according to the angles of the heading deflections recorded in the external parameter data set.

[0140] For example, when the number of heading deflections recorded in the external parameter data set is greater than or equal to a first preset number, the angles of the heading deflections recorded in the external parameter data set can be weighted and averaged, and the obtained average value is used as the calibration result of the heading deflection.

[0141] In one implementation, Figure 6 As shown, S22 may specifically include the following contents of S221-S223.

[0142] S221. Divide the heading deflection angles recorded in the extrinsic parameter data set into a third preset number of angle sets, where each angle set corresponds to an angle interval of a preset width.

[0143] For example, if 0.05 degrees is used as the preset width, the heading deflection angle recorded in the extrinsic parameter data set can be divided into 7200 (i.e., 360*0.05) angle sets from 0 degrees to 360 degrees, where 7200 corresponds to the third preset number.

[0144] S222: Determine, from the third preset number of angle sets, a fourth preset number of angle sets containing angles greater than or equal to a third threshold.

[0145] Continuing with the above example, assume that the third threshold value is 0.2*max_freq, where max_freq represents the number of angles in the angle set with the largest number of angles in the third preset number of angle sets. Furthermore, after dividing the heading deflection angles recorded in the extrinsic parameter data set into 7200 angle sets, a fourth preset number of angle sets containing angles greater than or equal to 0.2*max_freq can be determined from the 7200 angle sets.

[0146] Specifically, in actual application, a histogram Hist_1 can be constructed using the angle of the heading deflection recorded in the external parameter data set. The width of each bar (bin) in the histogram Hist_1 is a preset width (0.05deg is used as an example below), and the total width range of the histogram Hist_1 is 0deg-360deg, so that the histogram Hist_1 can include a total of 7200 (i.e., the third preset number) bins. Furthermore, by traversing all bins, the maximum frequency max_freq in each bin can be obtained. Furthermore, by traversing all bins and removing bins with a frequency less than 0.2*max_freq, a fourth preset number of bins is obtained, and the fourth preset number of bins can be formed into a new histogram Hist_2.

[0147] For example, Figure 7 As shown in FIG, it is a schematic diagram of some bins of the histogram Hist_1. Considering that there are too many bins (7200) included in the histogram Hist_1 in the above example, it is difficult to show all of them, and most of the data in the histogram Hist_1 are concentrated in Figure 7As shown, the range is between 88.85deg and 91.00deg. Figure 7 Only the bins between 88.85 degrees and 91.00 degrees are shown in FIG. It can be seen that by traversing all bins and removing bins with frequencies less than 0.2*max_freq, the 27 bins between 89.25 degrees and 90.55 degrees (ie, the fourth preset number of bins) can be used to form a new histogram Hist_2.

[0148] S223: Determine a calibration result of the heading angle according to a fourth preset number of angle sets.

[0149] For example, the heading deflection angles recorded in the fourth preset number of angle sets may be averaged, and the obtained average value may be used as the calibration result of the heading deflection angle.

[0150] In one design, Figure 8 As shown, the above S223 may specifically include the following contents of S2231-S2232:

[0151] S2231. Based on the fourth preset number of angle sets, determine the proportion of the number of angles contained in the fourth preset number of angle sets in the first preset number of angles, the median of the angles contained in the fourth preset number of angle sets, and the average number of angles contained in the fourth preset number of angle sets.

[0152] Specifically, the peak of the number of angles included in the fourth preset number of angle sets in the first preset number of angles can be determined according to the following formula (12):

[0153]

[0154] Among them, S Hist_2 is the number of angles included in the fourth preset number of angle sets, for example, in the above example S Hist_2 It may be the total frequency in the histogram Hist_2, and N is a first preset number. For example, in the above example, N may be the total frequency in the histogram Hist_1.

[0155] In addition, for example, taking the above histogram Hist_2 as an example, Figure 9 As shown in FIG, the median M of the angles included in the fourth preset number of angle sets is Hist_2 , and the average number A of angles included in the fourth preset number of angle sets Hist_2 .

[0156] S2232. When it is determined that the proportion of the number of angles included in the fourth preset number of angle sets in the first preset number of angles is greater than the fourth threshold, and the difference between the median of the angles included in the fourth preset number of angle sets and the average of the angles included in the fourth preset number of angle sets is less than the fifth threshold, the average is used as the calibration result of the heading deviation angle.

[0157] Specifically, the shift between the median of the angles included in the fourth preset number of angle sets and the average of the angles included in the fourth preset number of angle sets can be determined according to the following formula (13):

[0158] shift=|A Hist_2 -M Hist_2 Formula (13)

[0159] Among them, A Hist_2 represents the average number of angles contained in the fourth preset number of angle sets, M Hist_2 Represents the median of the angles included in the fourth preset number of angle sets.

[0160] Furthermore, when it is determined that peak>K1 and shift<K2, where K1 represents the fourth threshold and K2 represents the fifth threshold, the average value A Hist_2 As the calibration result of heading deflection angle.

[0161] In addition, in some implementations, after determining a calibration result of the heading angle according to the first preset number of heading angles, the method may further include:

[0162] S23. Clear the external reference data set and periodically execute the preset steps again.

[0163] Specifically, after determining the calibration result of the heading angle, the external parameter data set can be cleared and the preset steps can be periodically executed again to accumulate and record the heading angle in the external parameter data set. When the number of heading angles recorded in the external parameter data set is greater than or equal to a first preset number, the calibration result of the heading angle is determined again. In this way, the calibration result of the heading angle can be dynamically updated.

[0164] Based on the above method embodiment, the device provided by the embodiment of the present disclosure is described below. Figure 10 FIG. 3 is a schematic diagram of a device for calibrating the heading angle of a GNSS antenna provided by an embodiment of the present disclosure. Specifically, the calibration device 30 may be a chip or a system on a chip. For example, the calibration device 30 may be Figure 2The vehicle controller 111. The calibration device 30 can be used to implement the function of the calibration device of the heading angle of the GNSS antenna in the method provided in the embodiment of the present disclosure. Specifically, the calibration device 30 may include:

[0165] The collection unit 301 is configured to periodically execute preset steps while the vehicle carrying the GNSS is traveling;

[0166] The preset steps include:

[0167] Determine the positioning accuracy, heading accuracy, and driving speed corresponding to the current cycle;

[0168] Determine whether the following conditions are met simultaneously: the positioning accuracy meets the positioning accuracy condition, the heading accuracy meets the preset heading condition, and the driving speed is within the preset speed range;

[0169] If both conditions are met, the heading deflection angle between the GNSS and the vehicle is calculated and recorded in the external parameter data set.

[0170] The calibration unit 302 is configured to determine a calibration result of the heading deflection angle according to the heading deflection angle recorded in the extrinsic parameter data set when the number of the heading deflection angles recorded in the extrinsic parameter data set is greater than or equal to a first preset number.

[0171] In some implementations, determining the positioning accuracy corresponding to the current period includes:

[0172] Determine a first distance between a focus and a center of a GNSS positioning error ellipse within a current period;

[0173] Determine whether the following conditions are met simultaneously: the positioning accuracy meets the positioning accuracy condition, the heading accuracy meets the preset heading condition, and the driving speed is within the preset speed range, including:

[0174] Determine the baseline length of the mobile base station;

[0175] According to the following formula 1, the first threshold is determined;

[0176] σ_p max =K0(δ a +δ b ×l t ) Formula 1

[0177] Among them, σ_p max represents the first threshold, l t Indicates the baseline length of the mobile base station, K0, δ a and δ b is the default value;

[0178] When the first distance is less than a first threshold, determining that the positioning accuracy meets the positioning accuracy condition;

[0179] When the first distance is greater than or equal to a first threshold, determining that the positioning accuracy does not meet the positioning accuracy condition;

[0180] The positioning accuracy condition is as follows: the first distance is less than a first threshold.

[0181] In some implementations, determining the rover base station baseline length includes:

[0182] Determine the radius of the circle where the vehicle is located;

[0183] Calculate the ECEF coordinates of the vehicle based on the radius;

[0184] Determine the baseline length of the mobile base station based on the ECEF coordinates of the vehicle and the ECEF coordinates of the RTK base station.

[0185] In some implementations, determining a heading accuracy corresponding to a current period includes:

[0186] determining a standard deviation of a second predetermined number of heading angles;

[0187] The second preset number of heading angles is: the angle between the heading direction detected by GNSS and the preset direction within the second preset number of cycles including the current cycle;

[0188] Determine whether the following conditions are met simultaneously: the positioning accuracy meets the positioning accuracy condition, the heading accuracy meets the preset heading condition, and the driving speed is within the preset speed range, including:

[0189] According to the following formula 2, the second threshold is determined;

[0190]

[0191] Among them, σ_hmax represents the second threshold, K1 and δ c is a preset value, L represents the distance between the phase center points of the dual antennas in GNSS;

[0192] When the standard deviation is less than a second threshold, determining that the heading accuracy meets a preset heading condition;

[0193] When the standard deviation is greater than or equal to a second threshold, determining that the heading accuracy does not meet the preset heading condition;

[0194] The preset heading condition is: a standard deviation of a second preset number of heading angles is less than a second threshold.

[0195] In some implementations, determining a calibration result of the heading angle according to the heading angle recorded in the extrinsic parameter data set includes:

[0196] The calibration unit 302 is specifically configured to divide the heading deflection angle recorded in the extrinsic parameter data set into a third preset number of angle sets, wherein each angle set corresponds to an angle interval of a preset width;

[0197] The calibration unit 302 is specifically configured to determine, from the third preset number of angle sets, a fourth preset number of angle sets containing angles greater than or equal to a third threshold;

[0198] The calibration unit 302 is specifically configured to determine a calibration result of the heading angle according to a fourth preset number of angle sets.

[0199] In some implementations, the calibration unit 302 is specifically configured to determine a calibration result of the heading angle according to a fourth preset number of angle sets, including:

[0200] The calibration unit 302 is specifically configured to determine, based on the fourth preset number of angle sets, a proportion of the number of angles included in the fourth preset number of angle sets to the first preset number of angles, a median of the angles included in the fourth preset number of angle sets, and an average of the angles included in the fourth preset number of angle sets;

[0201] The calibration unit 302 is specifically configured to use the average as the calibration result of the heading angle when it is determined that the proportion is greater than the fourth threshold and the difference between the median and the average is less than the fifth threshold.

[0202] In some implementations, the calibration device 30 further includes: a loop unit 303, configured to clear the extrinsic parameter data set and periodically execute the preset steps again after determining the calibration result of the heading angle according to the first preset number of heading angles.

[0203] The calibration device 30 provided in the embodiment of the present disclosure can execute some or all of the steps in the above method. Its implementation principle and technical effect are similar and will not be repeated here.

[0204] Based on the same inventive concept, an embodiment of the present disclosure also provides another device for calibrating the heading angle of a GNSS antenna. Figure 11 A schematic diagram of the structure of a device for calibrating the heading angle of a GNSS antenna provided in an embodiment of the present disclosure is shown in FIG. Figure 11 As shown, the device for calibrating the heading angle of a GNSS antenna provided in this embodiment includes: a memory 401 and a processor 402, the memory 401 is used to store a computer program, and the processor 402 is used to execute any one of the methods provided in the above embodiments when executing the computer program.

[0205] Based on the same inventive concept, an embodiment of the present disclosure also provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a device for calibrating the heading angle of a GNSS antenna, the device for calibrating the heading angle of a GNSS antenna implements the method provided in the above embodiment.

[0206] Based on the same inventive concept, an embodiment of the present disclosure further provides a computer program product. When the computer program product is run on a computer, the computing device implements the method provided in the above embodiment.

[0207] Those skilled in the art will appreciate that embodiments of the present disclosure may be provided as methods, systems, or computer program products. Thus, the present disclosure may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware. Furthermore, the present disclosure may take the form of a computer program product implemented on one or more computer-usable storage media containing computer-usable program code.

[0208] The processor may be a central processing unit (CPU), other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA), other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or any conventional processor, etc.

[0209] The memory may include non-permanent memory in a computer-readable medium, random access memory (RAM) and / or non-volatile memory in the form of read-only memory (ROM) or flash RAM. The memory is an example of a computer-readable medium.

[0210] Computer-readable media includes both permanent and non-permanent, removable and non-removable storage media. Storage media can implement any method or technology for storing information, which can be computer-readable instructions, data structures, program modules, or other data. Examples of computer storage media include, but are not limited to, phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, compact disc read-only memory (CD-ROM), digital versatile disc (DVD) or other optical storage, magnetic cassettes, magnetic disk storage or other magnetic storage devices, or any other non-transmission media that can be used to store information that can be accessed by a computing device. As defined herein, computer-readable media does not include transitory computer-readable media, such as modulated data signals and carrier waves.

[0211] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present disclosure, rather than to limit the same. Although the present disclosure has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein, and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present disclosure.

Claims

1. A method for calibrating the heading angle of a GNSS antenna, characterized in that: The method comprises: During the driving process of the vehicle equipped with GNSS, the preset steps are executed periodically; The preset steps include: Determine the positioning accuracy, heading accuracy, and driving speed corresponding to the current cycle; Determine whether the following conditions are met simultaneously: the positioning accuracy satisfies a positioning accuracy condition, the heading accuracy satisfies a preset heading condition, and the driving speed is within a preset speed range; If both conditions are met, calculating the heading deflection angle between the GNSS and the vehicle, and recording the heading deflection angle in the extrinsic parameter data set; When the number of the heading deflections recorded in the extrinsic parameter data set is greater than or equal to a first preset number, a calibration result of the heading deflection is determined according to the angles of the heading deflections recorded in the extrinsic parameter data set.

2. The method according to claim 1, characterized in that Determining the positioning accuracy corresponding to the current period includes: Determine a first distance between a focus and a center of a positioning error ellipse of the GNSS in a current period; The determining whether the following conditions are met simultaneously: the positioning accuracy satisfies a positioning accuracy condition, the heading accuracy satisfies a preset heading condition, and the driving speed is within a preset speed range includes: Determine the baseline length of the mobile base station; According to the following formula 1, the first threshold is determined; σ_p max = K0(δ a + δ b × l t ) Equation 1 Among them, σ_p max represents the first threshold, l t Indicates the baseline length of the mobile base station, K0, δ a and δ b is the default value; When the first distance is less than the first threshold, determining that the positioning accuracy meets the positioning accuracy condition; When the first distance is greater than or equal to the first threshold, determining that the positioning accuracy does not meet the positioning accuracy condition; The positioning accuracy condition is: the first distance is less than the first threshold.

3. The method according to claim 2, characterized in that The determining of the baseline length of the mobile base station includes: Determine the radius of the circle in which the vehicle is located; Calculating the ECEF coordinates of the vehicle based on the radius; The baseline length of the rover base station is determined according to the ECEF coordinates of the vehicle and the ECEF coordinates of the RTK base station.

4. The method according to claim 1, wherein Determining the heading accuracy corresponding to the current period includes: determining a standard deviation of a second predetermined number of heading angles; The second preset number of heading angles is: the angle between the heading direction detected by the GNSS and the preset direction within the second preset number of cycles including the current cycle; The determining whether the following conditions are met simultaneously: the positioning accuracy satisfies a positioning accuracy condition, the heading accuracy satisfies a preset heading condition, and the driving speed is within a preset speed range includes: According to the following formula 2, the second threshold is determined; Wherein, σ_hmax represents the second threshold, K1 and δ c is a preset value, and L represents the distance between the phase center points of the dual antennas in the GNSS; When the standard deviation is less than the second threshold, determining that the heading accuracy meets the preset heading condition; When the standard deviation is greater than or equal to the second threshold, determining that the heading accuracy does not meet the preset heading condition; The preset heading condition is: the standard deviation of the second preset number of heading angles is less than a second threshold.

5. The method according to claim 1, wherein Determining a calibration result of the heading angle according to the heading angle recorded in the external parameter data set includes: Dividing the heading deflection angle recorded in the extrinsic parameter data set into a third preset number of angle sets, wherein each angle set corresponds to an angle interval of a preset width; Determining, from the third preset number of angle sets, a fourth preset number of angle sets containing angles greater than or equal to a third threshold; Determine the calibration result of the heading angle according to the fourth preset number of angle sets.

6. The method according to claim 5, characterized in that Determining the calibration result of the heading angle according to the fourth preset number of angle sets includes: Determining, based on the fourth preset number of angle sets, a proportion of the number of angles included in the fourth preset number of angle sets to the first preset number of angles, a median of the angles included in the fourth preset number of angle sets, and an average of the angles included in the fourth preset number of angle sets; When it is determined that the proportion is greater than a fourth threshold and the difference between the median and the average is less than a fifth threshold, the average is used as the calibration result of the heading angle.

7. The method according to any one of claims 1 to 6, characterized in that After determining the calibration result of the heading angle according to the first preset number of heading angles, the method further includes: Clear the external parameter data set and periodically execute the preset steps again.

8. A device for calibrating the heading angle of a GNSS antenna, characterized in that: include: The acquisition unit is used to periodically execute preset steps while the vehicle carrying the GNSS is traveling; The preset steps include: Determine the positioning accuracy, heading accuracy, and driving speed corresponding to the current cycle; Determine whether the following conditions are met simultaneously: the positioning accuracy satisfies a positioning accuracy condition, the heading accuracy satisfies a preset heading condition, and the driving speed is within a preset speed range; If both conditions are met, calculating the heading deflection angle between the GNSS and the vehicle, and recording the heading deflection angle in the extrinsic parameter data set; A calibration unit is used to determine a calibration result of the heading deflection angle according to the heading deflection angle recorded in the external parameter data set when the number of the heading deflection angles recorded in the external parameter data set is greater than or equal to a first preset number.

9. A device for calibrating the heading angle of a GNSS antenna, characterized in that: include: A memory and a processor, wherein the memory is used to store a computer program; and the processor is used to enable the device for calibrating the heading angle of the GNSS antenna to implement the method provided in any one of claims 1 to 7 when executing the computer program.

10. A computer-readable storage medium, characterized in that The computer-readable storage medium stores a computer program. When the computer program is executed by the device for calibrating the heading angle of a GNSS antenna, the device for calibrating the heading angle of a GNSS antenna implements the method according to any one of claims 1 to 7.

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