Method and apparatus for determining vehicle speed

Abstract

Embodiments of the present application provide a vehicle speed determination method and device, including obtaining a first vehicle speed, a second vehicle speed, a third vehicle speed of a vehicle under a target load, and corresponding speed correction coefficients respectively, correcting the first vehicle speed, the second vehicle speed and the third vehicle speed based on the speed correction coefficients corresponding to the first vehicle speed, the second vehicle speed and the third vehicle speed respectively, calculating a first difference value between the corrected first vehicle speed and the corrected third vehicle speed, and a second difference value between the corrected second vehicle speed and the corrected third vehicle speed, calculating a first ratio of the first difference value to the corrected first vehicle speed, and a second ratio of the second difference value to the corrected second vehicle speed, and determining the corrected third vehicle speed as a target vehicle speed in a case where the first ratio is less than or equal to a preset threshold value, and the second ratio is less than or equal to the preset threshold value. According to the embodiments of the present application, the accuracy of the vehicle speed is improved, and the accuracy of the high-precision positioning system is further improved.

Description

Technical Field

[0001] This application belongs to the field of high-precision positioning for autonomous driving, and in particular relates to a method and apparatus for determining vehicle speed. Background Technology

[0002] High-precision positioning is an important technology in the field of autonomous driving. Typically, high-precision positioning systems need to perform relevant positioning calculations based on vehicle speed. Vehicle speed calculation is performed using relevant vehicle signals. For high-precision positioning of heavy-load vehicles, vehicle speed is calculated based on the vehicle's wheel speed signals.

[0003] However, the vehicle rolling radius is usually considered to be a constant value in the process of calculating the vehicle wheel speed signal. Since the vehicle load of a heavy-load vehicle changes greatly and frequently, the change in vehicle load affects the wheel rolling radius. Therefore, the change in vehicle load will lead to inaccurate vehicle speed calculated based on the vehicle wheel speed signal, resulting in low accuracy and reliability of high-precision positioning results. Summary of the Invention

[0004] This application provides a method, apparatus, device, and computer storage medium for determining vehicle speed, which can solve the problem in the prior art where changes in vehicle load lead to inaccurate vehicle speed calculations based on vehicle wheel speed signals, resulting in low accuracy and reliability of high-precision positioning results.

[0005] In a first aspect, embodiments of this application provide a method for determining vehicle speed, the method comprising:

[0006] Obtain the vehicle's first, second, and third speeds under the target load, along with the corresponding speed correction coefficients for these speeds. The first speed is the chassis speed, the second speed is calculated based on the vehicle's transmission output shaft speed, and the third speed is calculated based on the vehicle's wheel speeds.

[0007] The first, second, and third vehicle speeds are corrected based on the speed correction coefficients corresponding to the first, second, and third vehicle speeds, respectively.

[0008] Calculate the first difference between the corrected first vehicle speed and the corrected third vehicle speed, and the second difference between the corrected second vehicle speed and the corrected third vehicle speed.

[0009] Calculate the first ratio of the first difference to the corrected first vehicle speed, and the second ratio of the second difference to the corrected second vehicle speed.

[0010] If the first ratio is greater than a preset threshold, and / or the second ratio is greater than a preset threshold, the corrected second vehicle speed will be determined as the target vehicle speed.

[0011] If the first ratio is less than or equal to a preset threshold and the second ratio is less than or equal to a preset threshold, the corrected third vehicle speed is determined as the target vehicle speed.

[0012] In some implementations, the first difference, the corrected first vehicle speed, and the first ratio satisfy the following relationship:

[0013]

[0014] Where, p 1v Here, v′1 is the corrected first vehicle speed, (v′1-v′3) is the first difference, and the abs(v′1-v′3) function is used to calculate the absolute value of (v′1-v′3).

[0015] The second difference, the corrected second vehicle speed, and the second ratio satisfy the following relationship:

[0016]

[0017] Where, p 2v The second ratio is given by v′2, the corrected second vehicle speed is given by v′2, and (v′2-v′3) is the second difference. The abs(v′2-v′3) function is used to calculate the absolute value of (v′2-v′3).

[0018] In some embodiments, before obtaining the first, second, and third vehicle speeds under the target load, and the speed correction coefficients corresponding to the first, second, and third vehicle speeds under the target load, the method further includes:

[0019] The system acquires the vehicle's first speed, second speed, third speed, and actual speed under at least one load. The actual speed is obtained through a preset speed measurement system. The at least one load includes a target load.

[0020] For each load, the ratios of the first vehicle speed, the second vehicle speed, and the third vehicle speed to the actual vehicle speed are determined as the speed correction coefficients corresponding to the first vehicle speed, the second vehicle speed, and the third vehicle speed, respectively.

[0021] In some implementations, the speed correction factor includes the unloaded vehicle speed calibration factor corresponding to the first vehicle speed, the second vehicle speed, and the third vehicle speed when the load is zero.

[0022] In some implementations...

[0023] In some embodiments, the first vehicle speed, the second vehicle speed, and the third vehicle speed include the first vehicle speed, the second vehicle speed, and the third vehicle speed obtained according to a preset frequency, and the method further includes:

[0024] If the vehicle is detected to be traveling at a constant speed and in a straight line, calculate the average value v of the corrected first vehicle speed within the first sliding time window. 1T and the mean of the corrected third vehicle speed v 3T And the average value v of the second vehicle speed after correction within the second sliding time window. 2T and the mean of the corrected third vehicle speed v 3T ′, wherein the first sliding time window and the second sliding time window are respectively based on the ratio error between the third abnormal vehicle speed and the actual vehicle speed being within a preset range, and the first sliding time window is set to be larger than the second sliding time window.

[0025] Calculate the mean v 1T With mean v 3T The third difference, and the mean v 2T With mean v 3T The fourth difference of ′,

[0026] Calculate the mean v of the third difference and the corrected first vehicle speed. 1T The first ratio p 1v ′, and the fourth difference and the mean v of the corrected second vehicle speed. 2T The second ratio p 2v ′,

[0027] Among them, the third difference and the mean of the corrected first vehicle speed, v 1T and the first ratio p 1v ′ satisfies the following relationship:

[0028]

[0029] Among them, abs(v 1T -v 3T The function is used to calculate (v) 1T -v 3T The absolute value of )

[0030] The fourth difference, the mean of the corrected second vehicle speed, v 2T And the second ratio p 2v ′ satisfies the following relationship:

[0031]

[0032] Among them, abs(v 2T -v 3T The function is used to calculate (v) 2T -v 3T The absolute value of ).

[0033] In some implementations, if the first difference is greater than a preset threshold and / or the second difference is greater than a preset threshold, the corrected second vehicle speed is determined as the target vehicle speed, including:

[0034] If the first difference is greater than a preset threshold, and / or the second difference is greater than a preset threshold, the target value is detected as a first preset value, which indicates an abnormality in the corrected third vehicle speed.

[0035] The corrected second vehicle speed is determined as the target vehicle speed.

[0036] In some implementations, when the first ratio is less than or equal to a preset threshold and the second ratio is less than or equal to a preset threshold, the corrected third vehicle speed is determined as the target vehicle speed, including:

[0037] If the first ratio is less than or equal to a preset threshold, and the second ratio is less than or equal to a preset threshold, the detected target value is the second preset value. The second preset value indicates that the corrected third vehicle speed is normal.

[0038] The corrected third speed is determined as the target speed.

[0039] In some implementations, the method further includes:

[0040] When the vehicle's wheel speed is at the default value or in the target state, the corrected second vehicle speed is determined as the target vehicle speed. The target state is when the vehicle's speed is zero when it is moving at low speed.

[0041] In some embodiments, the preset vehicle speed measurement system includes a differential GPS positioning system, and the method further includes:

[0042] When the vehicle is detected to be traveling at a constant speed and in a straight line, the differential GPS distance D within the third sliding time window is obtained. GPS and the target vehicle speed v out The vehicle mileage D is obtained by integral calculation. v The third sliding time window is determined based on the minimum speed among the first, second, and third vehicle speeds.

[0043] Vehicle mileage D v Differential GPS mobile mileage D GPS The ratio is determined as the vehicle speed error correction coefficient p. d ,

[0044] Based on vehicle speed error correction coefficient p d Correct target vehicle speed v out The corrected target vehicle speed v is obtained. final The corrected target vehicle speed v final Vehicle speed error correction coefficient p d and target vehicle speed v out The following relationship must be satisfied:

[0045] v final =v out / p d .

[0046] Secondly, embodiments of this application provide a vehicle speed determination device, which includes:

[0047] The acquisition module is used to acquire the vehicle's first, second, and third speeds under the target load, as well as the corresponding speed correction coefficients for the first, second, and third speeds under the target load. The first speed is the chassis speed, the second speed is calculated based on the vehicle's transmission output shaft speed, and the third speed is calculated based on the vehicle's wheel speeds.

[0048] The correction module is used to correct the first vehicle speed, the second vehicle speed, and the third vehicle speed based on the speed correction coefficients corresponding to the third vehicle speed, respectively.

[0049] The calculation module is used to calculate the first difference between the corrected first vehicle speed and the corrected third vehicle speed, and the second difference between the corrected second vehicle speed and the corrected third vehicle speed.

[0050] The calculation module is also used to calculate a first ratio of the first difference to the corrected first vehicle speed, and a second ratio of the second difference to the corrected second vehicle speed.

[0051] The determination module is used to determine the corrected second vehicle speed as the target vehicle speed when the first ratio is greater than a preset threshold and / or the second ratio is greater than a preset threshold.

[0052] The determining module is also used to determine the corrected third vehicle speed as the target vehicle speed when the first ratio is less than or equal to a preset threshold and the second ratio is less than or equal to a preset threshold.

[0053] In one implementation, the first difference, the corrected first vehicle speed, and the first ratio satisfy the following relationship:

[0054]

[0055] Where, p 1v Here, v′1 is the corrected first vehicle speed, (v′1-v′3) is the first difference, and the abs(v′1-v′3) function is used to calculate the absolute value of (v′1-v′3).

[0056] The second difference, the corrected second vehicle speed, and the second ratio satisfy the following relationship:

[0057]

[0058] Where, p2v The second ratio is given by v′2, the corrected second vehicle speed is given by v′2, and (v′2-v′3) is the second difference. The abs(v′2-v′3) function is used to calculate the absolute value of (v′2-v′3).

[0059] In one embodiment, the acquisition module is further configured to acquire, before acquiring the vehicle's first speed, second speed, and third speed under the target load, and the speed correction coefficients corresponding to the first speed, second speed, and third speed under the target load, the vehicle's first speed, second speed, third speed, and actual speed, wherein the actual speed is detected by a preset vehicle speed measurement system, and the at least one load includes the target load.

[0060] The determination module is also used to determine the ratios of the first vehicle speed, the second vehicle speed, and the third vehicle speed to the actual vehicle speed for each load, and to determine the speed correction coefficients corresponding to the first vehicle speed, the second vehicle speed, and the third vehicle speed.

[0061] In some implementations, the speed correction factor includes the unloaded vehicle speed calibration factor corresponding to the first vehicle speed, the second vehicle speed, and the third vehicle speed when the load is zero.

[0062] In one embodiment, the first vehicle speed, the second vehicle speed, and the third vehicle speed include the first vehicle speed, the second vehicle speed, and the third vehicle speed acquired at a preset frequency. The calculation module is further configured to calculate the average value v of the corrected first vehicle speed within a first sliding time window when the vehicle's operating state is detected as uniform speed and straight-line travel. 1T and the mean of the corrected third vehicle speed v 3T And the average value v of the second vehicle speed after correction within the second sliding time window. 2T and the mean of the corrected third vehicle speed v 3T ′, wherein the first sliding time window and the second sliding time window are respectively based on the ratio error between the third abnormal vehicle speed and the actual vehicle speed being within a preset range, and the first sliding time window is set to be larger than the second sliding time window.

[0063] Calculate the mean v 1T With mean v 3T The third difference, and the mean v 2T With mean v 3T The fourth difference of ′,

[0064] Calculate the mean v of the third difference and the corrected first vehicle speed. 1T The first ratio p 1v ′, and the fourth difference and the mean v of the corrected second vehicle speed. 2T The second ratio p 2v ′,

[0065] Among them, the third difference and the mean of the corrected first vehicle speed, v 1T and the first ratio p 1v ′ satisfies the following relationship:

[0066]

[0067] Among them, abs(v 1T -v 3T The function is used to calculate (v) 1T -v 3T The absolute value of )

[0068] The fourth difference, the mean of the corrected second vehicle speed, v 2T And the second ratio p 2v ′ satisfies the following relationship:

[0069]

[0070] Among them, abs(v 2T -v 3T The function ') is used to calculate (v 2T -v 3T The absolute value of ′).

[0071] In one embodiment, the vehicle speed determination device further includes a detection module.

[0072] The detection module is used to detect a target value as a first preset value when a first difference is greater than a preset threshold and / or a second difference is greater than a preset threshold. The first preset value represents an anomaly in the corrected third vehicle speed.

[0073] The determination module is also used to determine the corrected second vehicle speed as the target vehicle speed.

[0074] In one embodiment, the detection module is further configured to detect a target value as a second preset value when a first ratio is less than or equal to a preset threshold and a second ratio is less than or equal to a preset threshold. The second preset value indicates that the corrected third vehicle speed is normal.

[0075] The determination module is also used to determine the corrected third vehicle speed as the target vehicle speed.

[0076] In one implementation, the determining module is further configured to determine the corrected second vehicle speed as the target vehicle speed when the vehicle's wheel speed is a default value or when it is in a target state, wherein the target state is the state where the vehicle speed is zero when the vehicle is moving at low speed.

[0077] In one embodiment, the acquisition module is further configured to acquire the differential GPS distance D of the differential GPS positioning system within a third sliding time window when the vehicle's operating state is detected as constant speed and straight-line travel. GPSand the target vehicle speed v out The vehicle mileage D is obtained by integral calculation. v The third sliding time window is determined based on the minimum speed among the first, second, and third vehicle speeds.

[0078] The determination module is also used to determine the vehicle's mileage D. v Differential GPS mobile mileage D GPS The ratio is determined as the vehicle speed error correction coefficient p. d ,

[0079] The correction module is also used to correct vehicle speed error based on the vehicle speed error correction coefficient p. d Correct target vehicle speed v out The corrected target vehicle speed v is obtained. final The corrected target vehicle speed v final Vehicle speed error correction coefficient p d and target vehicle speed v out The following relationship must be satisfied:

[0080] v final =v out / p d .

[0081] Thirdly, embodiments of this application provide an electronic device, which includes: a processor and a memory storing computer program instructions;

[0082] When the processor executes computer program instructions, it implements the method for determining vehicle speed as described in any embodiment of the first aspect.

[0083] Fourthly, embodiments of this application provide a computer storage medium storing computer program instructions, which, when executed by a processor, implement the method for determining vehicle speed as described in any embodiment of the first aspect.

[0084] Fifthly, embodiments of this application provide a computer program product in which instructions, when executed by a processor of an electronic device, cause the electronic device to perform the vehicle speed determination method as described in any embodiment of the first aspect.

[0085] The method and apparatus for determining vehicle speed according to embodiments of this application acquire a first vehicle speed, a second vehicle speed, and a third vehicle speed under a target load, along with corresponding speed correction coefficients. The first vehicle speed is the chassis speed, and the second and third vehicle speeds are calculated based on the vehicle's transmission output shaft speed and wheel speed, respectively. Then, the first, second, and third vehicle speeds are corrected based on the speed correction coefficients. This allows for speed correction under different loads, reducing the impact of load on speed. Next, a first difference between the corrected first and third vehicle speeds, and a second difference between the corrected second and third vehicle speeds are calculated. A first ratio of the first difference to the corrected first vehicle speed, and a second ratio of the second difference to the corrected second vehicle speed, are also calculated. This allows for anomaly detection of the third vehicle speed calculated from the wheel speed. If the first ratio is greater than a preset threshold, and / or the second ratio is greater than a preset threshold, the corrected second vehicle speed is determined as the target vehicle speed; that is, when the third vehicle speed is abnormal, the second vehicle speed is output as the target vehicle speed. When the first ratio is less than or equal to a preset threshold and the second ratio is less than or equal to a preset threshold, that is, when the third vehicle speed is normal, the third vehicle speed is output as the target vehicle speed, which improves the accuracy of vehicle speed and thus improves the accuracy and reliability of the high-precision positioning system. Attached Figure Description

[0086] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments of this application will be briefly introduced below. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0087] Figure 1 This is one of the flowcharts illustrating a method for determining vehicle speed according to an embodiment of this application;

[0088] Figure 2 This is a schematic diagram of a process for detecting abnormal vehicle speed provided in one embodiment of this application;

[0089] Figure 3 This is a schematic diagram of state maintenance when the vehicle speed is abnormal, provided in one embodiment of this application;

[0090] Figure 4 This is a second schematic flowchart of a method for determining vehicle speed provided in one embodiment of this application;

[0091] Figure 5 This is a schematic diagram of the structure of a vehicle speed determination device provided in one embodiment of this application;

[0092] Figure 6 This is a schematic diagram of the structure of an electronic device provided in one embodiment of this application. Detailed Implementation

[0093] The features and exemplary embodiments of various aspects of this application will be described in detail below. To make the objectives, technical solutions, and advantages of this application clearer, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are intended only to explain this application and not to limit it. For those skilled in the art, this application can be implemented without some of these specific details. The following description of the embodiments is merely to provide a better understanding of this application by illustrating examples.

[0094] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising..." does not exclude the presence of additional identical elements in the process, method, article, or apparatus that includes said element.

[0095] As described in the background section, in the prior art, changes in vehicle load can lead to inaccurate vehicle speed calculations based on vehicle wheel speed signals, and the accuracy is lower than that of passenger cars and commercial vehicles, resulting in lower precision and reliability of high-precision positioning results.

[0096] To address the aforementioned problems, this application provides a method and apparatus for determining vehicle speed. The method involves acquiring a first vehicle speed, a second vehicle speed, and a third vehicle speed under a target load, along with corresponding speed correction coefficients. The first vehicle speed is the chassis speed, while the second and third speeds are calculated based on the vehicle's transmission output shaft speed and wheel speed, respectively. Next, the first, second, and third vehicle speeds are corrected based on the speed correction coefficients. This allows for speed correction under different loads, reducing the impact of load on speed. Then, a first difference between the corrected first and third vehicle speeds, and a second difference between the corrected second and third vehicle speeds are calculated. A first ratio of the first difference to the corrected first vehicle speed, and a second ratio of the second difference to the corrected second vehicle speed, are calculated. This allows for anomaly detection of the third vehicle speed calculated from the wheel speeds. If the first ratio is greater than a preset threshold, and / or the second ratio is greater than a preset threshold, the corrected second vehicle speed is determined as the target vehicle speed; that is, when the third vehicle speed is abnormal, the second vehicle speed is output as the target vehicle speed. When the first ratio is less than or equal to a preset threshold and the second ratio is less than or equal to a preset threshold, that is, when the third vehicle speed is normal, the third vehicle speed is output as the target vehicle speed, which improves the accuracy of vehicle speed and thus improves the accuracy and reliability of the high-precision positioning system. The method for determining vehicle speed provided in the embodiments of this application will be introduced below.

[0097] Figure 1 A flowchart illustrating a method for determining vehicle speed according to an embodiment of this application is shown.

[0098] like Figure 1 As shown, the method for determining vehicle speed may specifically include the following steps:

[0099] S110, obtain the first vehicle speed, second vehicle speed, and third vehicle speed under the target load, as well as the speed correction coefficients corresponding to the first vehicle speed, second vehicle speed, and third vehicle speed under the target load.

[0100] Here, the target load can be any vehicle load. The first vehicle speed is the chassis speed, which can be, for example, the reference speed calculated by the vehicle's anti-lock braking system (ABS). The reference speed is relatively stable during vehicle operation and can be used to verify other speeds.

[0101] The second vehicle speed can be calculated based on the output shaft speed of the vehicle's transmission, which can be output from the transmission. The second vehicle speed v2 is calculated based on the shaft speed, for example, as shown below:

[0102]

[0103] Among them, v s This indicates the shaft speed, measured in revolutions per minute (RPM); f ratio This indicates the gear ratio from the gearbox output shaft to the wheel; r represents the wheel rolling radius, in meters (m).

[0104] The third speed can be calculated based on the vehicle's wheel speeds, which directly reflect the vehicle's motion. The third speed v3 is calculated based on wheel speeds, for example, as shown below:

[0105] v3=(v l +v r ) / 2

[0106] Among them, v l This indicates the speed of the left wheel, measured in meters per second (m / s); v r This indicates the speed of the right wheel, in m / s.

[0107] Because the rolling radius of the wheels varies under different loads, the aforementioned first, second, and third vehicle speeds usually deviate from the actual vehicle speeds. Since the different rolling radii of the wheels under different loads affect these speeds, the speed correction coefficients corresponding to the first, second, and third vehicle speeds under the target load are obtained by mapping the first, second, and third vehicle speeds under different loads to speed correction coefficients. These speed correction coefficients can be used to correct the first, second, and third vehicle speeds.

[0108] S120 corrects the first vehicle speed, the second vehicle speed, and the third vehicle speed based on the speed correction coefficients corresponding to the first vehicle speed, the second vehicle speed, and the third vehicle speed, respectively.

[0109] The first vehicle speed is corrected based on the speed correction factor corresponding to the first vehicle speed, the second vehicle speed is corrected based on the speed correction factor corresponding to the second vehicle speed, and the third vehicle speed is corrected based on the speed correction factor corresponding to the third vehicle speed.

[0110] For example, the first vehicle speed, the second vehicle speed, and the third vehicle speed are v1, v2, and v3, respectively, and the load-speed correction coefficients f corresponding to v1, v2, and v3 are... load The values ​​are k1, k2, and k3, respectively. Based on k1, k2, and k3, v1, v2, and v3 are modified respectively, that is, the modified first vehicle speed v′1 = k1v1, the modified second vehicle speed v′2 = k2v2, and the modified third vehicle speed v′3 = k3v3.

[0111] S130, calculate the first difference between the corrected first vehicle speed and the corrected third vehicle speed, and the second difference between the corrected second vehicle speed and the corrected third vehicle speed.

[0112] The first difference can be the difference between the corrected first speed and the corrected third speed, or it can be the absolute value of that difference. The second difference can be the difference between the corrected second speed and the corrected third speed, or it can be the absolute value of that difference.

[0113] S140, calculate the first ratio of the first difference to the corrected first vehicle speed, and the second ratio of the second difference to the corrected second vehicle speed.

[0114] In some embodiments, the first difference, the corrected first vehicle speed, and the first ratio satisfy the following relationship:

[0115]

[0116] Where, p 1v Here, v′1 is the corrected first vehicle speed, (v′1-v′3) is the first difference, and the abs(v′1-v′3) function is used to calculate the absolute value of (v′1-v′3).

[0117] The second difference, the corrected second vehicle speed, and the second ratio satisfy the following relationship:

[0118]

[0119] Where, p 2v The second ratio is given by v′2, the corrected second vehicle speed is given by v′2, and (v′2-v′3) is the second difference. The abs(v′2-v′3) function is used to calculate the absolute value of (v′2-v′3).

[0120] S150, if the first ratio is greater than a preset threshold and / or the second ratio is greater than a preset threshold, the corrected second vehicle speed is determined as the target vehicle speed.

[0121] Anomaly checks are performed on the corrected third vehicle speed based on the corrected first and second vehicle speeds, respectively. If the first ratio is greater than a preset threshold, the corrected second vehicle speed is determined as the target speed; if the second ratio is greater than a preset threshold, the corrected second vehicle speed is determined as the target speed; if both the first and second ratios are greater than the preset thresholds, the corrected second vehicle speed is determined as the target speed.

[0122] When the first ratio of the first difference to the corrected first speed is greater than a preset threshold, and / or the second ratio of the second difference to the corrected second speed is greater than a preset threshold, it indicates that the difference between the corrected third speed and the corrected first speed is large, and / or the difference between the corrected third speed and the corrected second speed is large, that is, the corrected third speed is abnormal. The preset threshold here can be a speed threshold that the user can arbitrarily set according to actual needs and experience.

[0123] S160, if the first ratio is less than or equal to a preset threshold and the second ratio is less than or equal to a preset threshold, the corrected third vehicle speed is determined as the target vehicle speed.

[0124] When the first ratio is less than or equal to a preset threshold and the second ratio is less than or equal to a preset threshold, it indicates that the difference between the corrected third vehicle speed and the corrected first vehicle speed is small, and the difference between the corrected third vehicle speed and the corrected second vehicle speed is also small, that is, the corrected third vehicle speed is normal.

[0125] In this embodiment, the vehicle's first, second, and third speeds under the target load, along with their corresponding speed correction coefficients, are obtained. The first speed is the chassis speed, while the second and third speeds are calculated based on the vehicle's transmission output shaft speed and wheel speed, respectively. Then, the first, second, and third speeds are corrected based on the speed correction coefficients. This allows for speed correction under different loads, reducing the impact of load on speed. Next, a first difference between the corrected first and third speeds, and a second difference between the corrected second and third speeds are calculated. A first ratio of the first difference to the corrected first speed, and a second ratio of the second difference to the corrected second speed, are also calculated. This allows for anomaly detection of the third speed calculated from the wheel speed. If the first ratio is greater than a preset threshold, and / or the second ratio is greater than a preset threshold, the corrected second speed is determined as the target speed; that is, when the third speed is abnormal, the second speed is output as the target speed. When the first ratio is less than or equal to a preset threshold and the second ratio is less than or equal to a preset threshold, that is, when the third vehicle speed is normal, the third vehicle speed is output as the target vehicle speed, which improves the accuracy of vehicle speed and thus improves the accuracy and reliability of the high-precision positioning system.

[0126] In some embodiments, prior to S110, the method for determining the vehicle speed may further include:

[0127] Obtain the vehicle's first speed, second speed, third speed, and actual speed under at least one load.

[0128] For each load, the ratios of the first vehicle speed, the second vehicle speed, and the third vehicle speed to the actual vehicle speed are determined as the speed correction coefficients corresponding to the first vehicle speed, the second vehicle speed, and the third vehicle speed, respectively.

[0129] The actual vehicle speed can be obtained by detecting a preset vehicle speed measurement system, which can be a differential GPS positioning system or other external speed or distance measurement system.

[0130] For each load of the vehicle under at least one load, the ratio of the first vehicle speed to the actual vehicle speed is determined as the speed correction coefficient corresponding to the first vehicle speed, the ratio of the second vehicle speed to the actual vehicle speed is determined as the speed correction coefficient corresponding to the second vehicle speed, and the ratio of the third vehicle speed to the actual vehicle speed is determined as the speed correction coefficient corresponding to the third vehicle speed. In this way, the correspondence between the first vehicle speed, the second vehicle speed, and the third vehicle speed and the speed correction coefficient under each load can be obtained. At least one load may include the target load.

[0131] In some embodiments, the speed correction factor may include the unloaded vehicle speed calibration factor corresponding to the first vehicle speed, the second vehicle speed, and the third vehicle speed when the load is zero.

[0132] As an example, the load-speed correction factor f for commercial vehicles of the same model and tire type load Since they are similar, the vehicle speed correction can be divided into two parts: unloaded and loaded. When vehicles of the same model are put into operation, only the unloaded speed calibration coefficient needs to be calibrated. Specifically, when the vehicle is unloaded, the Differential Global Positioning System (GPS) is used as the actual vehicle speed measurement system to calibrate the unloaded speed calibration coefficients n1, n2, and n3, corresponding to vehicle speeds v1, v2, and v3, respectively. The second part, when the vehicle is loaded, uses the Differential GPS positioning system as the actual vehicle speed measurement system to calibrate the load-speed correction coefficient f under different loads. load When other vehicles of the same model are subsequently added to the operation, only the no-load speed calibration coefficient needs to be calibrated. The speed correction coefficient for the vehicle under different loads should be the same as the aforementioned load-speed correction coefficient f. load The patterns of change are consistent.

[0133] Therefore, by calibrating the unloaded vehicle speed calibration coefficients corresponding to the first, second, and third vehicle speeds when the target load is zero, and then calibrating the speed correction coefficients corresponding to the first, second, and third vehicle speeds under different loads, the number of calibrations can be reduced and efficiency improved.

[0134] In this embodiment, the vehicle's first speed, second speed, third speed, and actual speed under at least one load are obtained. For each load, the ratios of the first speed, second speed, and third speed to the actual speed are determined as speed correction coefficients corresponding to the first speed, second speed, and third speed, respectively. This allows for the determination of the correspondence between the first speed, second speed, and third speed under each load and the speed correction coefficients, facilitating subsequent speed correction based on the target load.

[0135] In some embodiments, the first vehicle speed, the second vehicle speed, and the third vehicle speed may include the first vehicle speed, the second vehicle speed, and the third vehicle speed obtained at a preset frequency, and the method further includes:

[0136] If the vehicle is detected to be traveling at a constant speed and in a straight line, calculate the average value v of the corrected first vehicle speed within the first sliding time window. 1T and the mean of the corrected third vehicle speed v 3T And the average value v of the second vehicle speed after correction within the second sliding time window. 2T and the mean of the corrected third vehicle speed v 3T ′, wherein the first sliding time window and the second sliding time window are respectively based on the ratio error between the third abnormal vehicle speed and the actual vehicle speed being within a preset range, and the first sliding time window is set to be larger than the second sliding time window.

[0137] Calculate the mean v 1T With mean v 3T The third difference, and the mean v 2T With mean v 3T The fourth difference of ′,

[0138] Calculate the mean v of the third difference and the corrected first vehicle speed. 1T The first ratio p 1v ′, and the fourth difference and the mean v of the corrected second vehicle speed. 2T The second ratio p 2v ′,

[0139] Among them, the third difference and the mean of the corrected first vehicle speed, v 1T and the first ratio p 1v ′ satisfies the following relationship:

[0140]

[0141] Among them, abs(v 1T -v 3T The function is used to calculate (v) 1T -v 3T The absolute value of )

[0142] The fourth difference, the mean of the corrected second vehicle speed, v 2T And the second ratio p 2v ′ satisfies the following relationship:

[0143]

[0144] Among them, abs(v 2T -v 3T The function ') is used to calculate (v 2T -v 3T The absolute value of ′).

[0145] The preset frequency can be any frequency set by the user. If the vehicle is traveling at a constant speed and in a straight line, the average value v of the corrected first vehicle speed within the first sliding time window is calculated. 1T and the mean of the corrected third vehicle speed v 3T And the average value v of the second vehicle speed after correction within the second sliding time window. 2T and the mean of the corrected third vehicle speed v 3T The first and second sliding time windows can be set within a preset range based on the proportional error between the third abnormal vehicle speed and the actual vehicle speed. Since the specific calculation process for the first vehicle speed (chassis speed) is unclear, the first sliding time window is set to be relatively long, for example, 2 minutes. Because the second vehicle speed (vehicle speed calculated based on axle rotation speed) fluctuates, the second sliding time window is set to be relatively short, for example, 40 seconds. The first sliding time window is longer than the second sliding time window.

[0146] Calculate the mean v 1T With mean v 3T The third difference, and the mean v 2T With mean v 3T The fourth difference is given by ', where the third and fourth differences can be absolute values. Then, the mean value v of the third difference and the corrected first vehicle speed is calculated. 1T The first ratio p 1v ′, and the fourth difference and the mean v of the corrected second vehicle speed. 2T The second ratio p 2v As an example, such as Figure 2 As shown, S201 is the reference vehicle speed, where the corrected first vehicle speed v′1 is used as the reference speed. S202 is the vehicle speed to be tested, where the corrected third vehicle speed v′3 is used as the vehicle speed to be tested, and anomaly detection is performed on v′3 based on v′1. A normal state for v′3 is defined as Flag = 0, and an abnormal state as Flag = 1. S203 and S204 are the data filtering for vehicles traveling at constant speed in a straight line, obtaining vehicle speed data under the condition of constant speed travel in a straight line. S205 is the average reference vehicle speed for a sliding time window, calculating a 2-minute sliding time window T. v1The mean v of inner v′1 1T S206, the average speed of the vehicle to be tested within a sliding time window; calculate the 2-minute sliding time window T. v1 The mean v of inner v′3 3T S207, calculate the percentage difference between the average speeds of the two vehicles, i.e., calculate the average speed v. 1T and mean v 3T The percentage difference between them is shown below:

[0147]

[0148] S208, Determine if the percentage difference is greater than the threshold. If yes, proceed to S209; otherwise, proceed to S210. S209, If the outlier is 1, when p... 1v When v'' is greater than the threshold of 4%, v'3 is considered abnormal, and Flag = 1. S210, the abnormal value is equal to 0, when p 1v When v′ is less than or equal to the threshold of 4%, v′3 is considered normal, and Flag = 0.

[0149] Anomaly detection is performed on v′3 based on v′2 in the same manner. The corrected second vehicle speed v′2 is used as the base vehicle speed (reference vehicle speed), and the corrected third vehicle speed v′3 is used as the speed to be tested. Under the condition of the vehicle traveling straight at a constant speed, a sliding time window T of 40 seconds is calculated. v2 The mean v of v′2 and v′3 within 2T and v 3T Calculate the percentage difference between the two, as shown below:

[0150]

[0151] When p 2v When v′ is greater than the threshold of 4%, v′3 is considered abnormal, and Flag = 1. When p 2v ′ less than or equal to the threshold 4%, and p 2v When v′ is less than or equal to the threshold of 4%, v′3 is considered normal, and Flag = 0.

[0152] In this embodiment, when the vehicle is detected to be traveling at a constant speed and in a straight line, the average value v of the corrected first vehicle speed within the first sliding time window is calculated. 1T and the mean of the corrected third vehicle speed v 3T And the average value v of the second vehicle speed after correction within the second sliding time window. 2T and the mean of the corrected third vehicle speed v 3T ′, and calculate the mean v 1T With mean v 3T The third difference, and the mean v 2T With mean v 3TThe fourth difference is then used to calculate the mean value v of the third difference and the corrected first vehicle speed. 1T The first ratio p 1v ′, and the fourth difference and the mean v of the corrected second vehicle speed. 2T The second ratio p 2v In this way, the average value of the third vehicle speed can be checked for anomalies based on the average values ​​of the first and second vehicle speeds within different sliding time windows. The sliding time windows can be set by utilizing the different characteristics of the first and second vehicle speeds, which improves the convenience of checking for anomalies in the third vehicle speed.

[0153] In some embodiments, S150 may specifically include:

[0154] If the first ratio is greater than a preset threshold, and / or the second ratio is greater than a preset threshold, the target value is detected as a first preset value, which indicates an abnormal third vehicle speed after correction.

[0155] The corrected second vehicle speed is determined as the target vehicle speed.

[0156] If the first ratio is greater than a preset threshold and / or the second ratio is greater than a preset threshold, the target value Flag is detected as the first preset value. The first preset value can be any pre-set value, such as 1, which is used to characterize the abnormal state of the corrected third vehicle speed. At this time, the corrected second vehicle speed is determined to be the target vehicle speed.

[0157] In addition, when the target value Flag is detected to be the first preset value, the corrected second speed is maintained as the target speed for a preset time period. The preset time period can be a time period set by the user according to actual needs, such as 5 minutes.

[0158] For example, such as Figure 3 As shown, the normal state of v′3 is defined as Flag = 0, and the abnormal state is Flag = 1. When Flag = 1 is detected, v′3 usually will not return to normal in a short time. In addition, this is also to prevent the output of the target vehicle speed from being affected by the result v. out Frequent switching between v′2 and v′3 will maintain the abnormal state Flag=1 of v′3 for a period of time, such as about 5 minutes. During this 5-minute period, v′3 is maintained as the output target vehicle speed. In this embodiment, when the first ratio is greater than a preset threshold and / or the second ratio is greater than a preset threshold, the target value is detected as a first preset value. The first preset value indicates that the corrected third vehicle speed is abnormal, and the corrected second vehicle speed is determined to be the target vehicle speed. In this way, the abnormal situation of the corrected third vehicle speed can be determined by detecting the target value, which improves the efficiency of determining the target vehicle speed.

[0159] In some embodiments, S160 may specifically include:

[0160] If the first ratio is less than or equal to a preset threshold, and the second ratio is less than or equal to a preset threshold, the detected target value is the second preset value. The second preset value indicates that the corrected third vehicle speed is normal.

[0161] The corrected third speed is determined as the target speed.

[0162] If the first ratio is less than or equal to a preset threshold, and / or the second ratio is less than or equal to a preset threshold, the target value Flag is detected as the second preset value. The second preset value can be any pre-set value, such as 0, which is used to indicate that the corrected third vehicle speed is normal. At this time, the corrected third vehicle speed is determined to be the target vehicle speed.

[0163] In this embodiment of the application, when the first ratio is less than or equal to a preset threshold and / or the second ratio is less than or equal to a preset threshold, the target value is detected as a second preset value. The second preset value indicates that the corrected third vehicle speed is normal, and the corrected third vehicle speed is determined to be the target vehicle speed. In this way, the abnormal situation of the corrected third vehicle speed can be determined by detecting the target value, which improves the efficiency of determining the target vehicle speed.

[0164] In some embodiments, the method for determining vehicle speed may further include:

[0165] When the vehicle's wheel speed is at the default value or in the target state, the corrected second vehicle speed is determined as the target vehicle speed. The target state is when the vehicle's speed is zero when it is moving at low speed.

[0166] Default values ​​can be, for example, values ​​defined by the bus. When the vehicle's wheel speed is at the default value, it indicates an anomaly in data transmission. The target state can be a state where the vehicle's speed is zero when moving at low speed, such as being in a dead zone, where the vehicle speed does not match the actual speed. When the vehicle's wheel speed is at the default value or in the target state, the corrected third speed is determined to be an abnormal state. For example, if the normal state of the corrected third speed v′3 is defined as Flag = 0, and the abnormal state as Flag = 1, then when the vehicle's wheel speed is at the default value or in the target state, Flag = 1.

[0167] In this embodiment of the application, by determining the corrected second vehicle speed as the target vehicle speed when the vehicle's wheel speed is at the default value or in the target state, the accuracy of the target vehicle speed can be improved.

[0168] In some embodiments, the preset vehicle speed measurement system includes a differential GPS positioning system, and the method for determining the vehicle speed may further include:

[0169] When the vehicle is detected to be traveling at a constant speed and in a straight line, the differential GPS distance D within the third sliding time window is obtained. GPS and the target vehicle speed v out The vehicle mileage D is obtained by integral calculation. v The third sliding time window is determined based on the minimum speed among the first, second, and third vehicle speeds.

[0170] Vehicle mileage D v Differential GPS mobile mileage D GPS The ratio is determined as the vehicle speed error correction coefficient p. d ,

[0171] Based on vehicle speed error correction coefficient p d Correct target vehicle speed v out The corrected target vehicle speed v is obtained. final The corrected target vehicle speed v final Vehicle speed error correction coefficient p d and target vehicle speed v out The following relationship must be satisfied:

[0172] v final =v out / p d .

[0173] Differential GPS positioning systems can be external speed and distance measurement systems, independent of the vehicle's internal conditions. The differential GPS positioning system's distance traveled (D) within the third sliding time window is statistically analyzed under the condition of the vehicle traveling at a constant speed in a straight line. GPS The third sliding time window can be determined based on the minimum speed among the first, second, and third vehicle speeds. If the minimum speed is faster, a shorter third sliding time window can be set; if the minimum speed is slower, a longer third sliding time window can be set.

[0174] For the target vehicle speed v out The vehicle's mileage D is obtained by integral calculation. v The vehicle's mileage D v Differential GPS mobile mileage D GPS The ratio of the two values ​​is used as the vehicle speed error correction coefficient p. d To be used to correct the target vehicle speed v out The corrected target vehicle speed v is obtained. final .

[0175] As an example, the calibrated load-velocity correction factor f load After correcting the vehicle speed and performing anomaly checks, the output target vehicle speed v is... outThere may still be a certain proportional error between the actual speed and the actual vehicle speed. Differential GPS positioning systems can obtain vehicle positions with centimeter-level accuracy in real time. Therefore, using the positioning results of the differential GPS positioning system as a benchmark, the output v... out Error correction is performed. In a statistical differential GPS positioning system operating at a constant speed in a straight line, the sliding time window T... d Differential GPS mobile mileage D within GPS and v out The vehicle mileage D is obtained by integral calculation. v Then, the vehicle speed correction factor is calculated, as shown below:

[0176]

[0177] With the vehicle speed correction factor p d For v out The vehicle speed is adjusted iteratively based on the speed correction coefficient, and the final vehicle speed v is obtained. final =v out / p d .

[0178] In this embodiment, by detecting that the vehicle is traveling at a constant speed and in a straight line, the differential GPS distance D within the third sliding time window is obtained by the differential GPS positioning system. GPS and the target vehicle speed v out The vehicle mileage D is obtained by integral calculation. v And the vehicle mileage D v Differential GPS mobile mileage D GPS The ratio is determined as the vehicle speed error correction coefficient p. d Therefore, based on the vehicle speed error correction coefficient p d Correct target vehicle speed v out The corrected target vehicle speed v is obtained. final In this way, by using the differential GPS positioning results to correct the output vehicle speed, a high-precision vehicle speed signal can be obtained for high-precision positioning, which improves the accuracy and reliability of the high-precision positioning system and thus enhances the driving safety of autonomous vehicles.

[0179] Therefore, to better describe the vehicle speed determination method in the embodiments of this application, a specific example is given, such as... Figure 4 As shown, the chassis speed v1, axle speed and wheel speed are obtained, and the vehicle speed v2 is calculated based on the axle speed and the vehicle speed v3 is calculated based on the wheel speed. Among them, the chassis speed v1 is relatively stable and can be used as a reference speed to verify other speeds.

[0180] First, the three vehicle speeds are corrected based on the vehicle speed calibration coefficient of GPS location. However, there is usually still a certain deviation between the corrected speed and the actual speed. Since the load of the vehicle will affect the speed, the load speed correction coefficient under different vehicle loads is used to correct the three vehicle speeds.

[0181] Next, based on vehicle speeds v1 and v2, anomaly detection is performed on vehicle speed v3, checking the abnormal speed flag, the default speed flag, and the dead zone speed flag. When a speed anomaly occurs, the abnormal speed flag is maintained for a period of time. When the above three flags are 0, v3 is considered normal; when they are 1, v3 is considered abnormal. If any one of the three flags is detected as 1, vehicle speed v3 is considered abnormal, and vehicle speed v2 is output as the target vehicle speed v. out If all three flags are detected to be Flag=1, it indicates that the vehicle speed v3 is normal, and the output vehicle speed v3 is the target vehicle speed v. out .

[0182] Then, due to the target vehicle speed v output out There may still be a certain proportional error between the differential GPS position and the actual vehicle speed. Therefore, it is necessary to correct for the vehicle speed error based on the differential GPS position. When the differential GPS meets preset conditions, i.e., the differential GPS state is under constant speed straight-line conditions, the differential GPS travel distance D is calculated. GPS and the target vehicle speed v out The vehicle's mileage D is obtained by integral calculation. v The vehicle speed correction factor is calculated as follows:

[0183]

[0184] With vehicle speed correction factor p d For v out After iterative correction, the corrected vehicle speed is the final high-precision output speed v4 = v out / p d .

[0185] Figure 5 This is a schematic diagram of the structure of a vehicle speed determination device 500 according to an exemplary embodiment.

[0186] like Figure 5 As shown, the vehicle speed determining device 500 may include:

[0187] The acquisition module 501 is used to acquire the first vehicle speed, the second vehicle speed, and the third vehicle speed under the target load, as well as the speed correction coefficients corresponding to the first vehicle speed, the second vehicle speed, and the third vehicle speed under the target load. The first vehicle speed is the chassis speed, the second vehicle speed is calculated based on the vehicle's transmission output shaft speed, and the third vehicle speed is calculated based on the vehicle's wheel speed.

[0188] Correction module 502 is used to correct the first vehicle speed, the second vehicle speed, and the third vehicle speed based on the speed correction coefficients corresponding to the first vehicle speed, the second vehicle speed, and the third vehicle speed, respectively.

[0189] The calculation module 503 is used to calculate the first difference between the corrected first vehicle speed and the corrected third vehicle speed, and the second difference between the corrected second vehicle speed and the corrected third vehicle speed.

[0190] The calculation module is also used to calculate a first ratio of the first difference to the corrected first vehicle speed, and a second ratio of the second difference to the corrected second vehicle speed.

[0191] The determining module 504 is used to determine the corrected second vehicle speed as the target vehicle speed when the first ratio is greater than a preset threshold and / or the second ratio is greater than a preset threshold.

[0192] The determining module is also used to determine the corrected third vehicle speed as the target vehicle speed when the first ratio is less than or equal to a preset threshold and the second ratio is less than or equal to a preset threshold.

[0193] In one implementation, the first difference, the corrected first vehicle speed, and the first ratio satisfy the following relationship:

[0194]

[0195] Where, p 1v Here, v′1 is the corrected first vehicle speed, (v′1-v′3) is the first difference, and the abs(v′1-v′3) function is used to calculate the absolute value of (v′1-v′3).

[0196] The second difference, the corrected second vehicle speed, and the second ratio satisfy the following relationship:

[0197]

[0198] Where, p 2v The second ratio is given by v′2, the corrected second vehicle speed is given by v′2, and (v′2-v′3) is the second difference. The abs(v′2-v′3) function is used to calculate the absolute value of (v′2-v′3).

[0199] In one embodiment, the acquisition module 501 is further configured to acquire, before acquiring the first vehicle speed, second vehicle speed, and third vehicle speed under the target load, and the speed correction coefficients corresponding to the first vehicle speed, second vehicle speed, and third vehicle speed under the target load, the first vehicle speed, second vehicle speed, and third vehicle speed, and the actual vehicle speed, wherein the actual vehicle speed is detected by a preset vehicle speed measurement system, and the at least one load includes the target load.

[0200] The determination module 504 is also used to determine the ratios of the first vehicle speed, the second vehicle speed, and the third vehicle speed to the actual vehicle speed for each load, and to determine the speed correction coefficients corresponding to the first vehicle speed, the second vehicle speed, and the third vehicle speed respectively.

[0201] In some implementations, the speed correction factor includes the unloaded vehicle speed calibration factor corresponding to the first vehicle speed, the second vehicle speed, and the third vehicle speed when the load is zero.

[0202] In one embodiment, the first vehicle speed, the second vehicle speed, and the third vehicle speed include the first vehicle speed, the second vehicle speed, and the third vehicle speed acquired at a preset frequency. The calculation module 503 is further configured to calculate the average value v of the corrected first vehicle speed within a first sliding time window when the vehicle is detected to be traveling at a constant speed and in a straight line. 1T and the mean of the corrected third vehicle speed v 3T And the average value v of the second vehicle speed after correction within the second sliding time window. 2T and the mean of the corrected third vehicle speed v 3T ′, wherein the first sliding time window and the second sliding time window are respectively based on the ratio error between the third abnormal vehicle speed and the actual vehicle speed being within a preset range, and the first sliding time window is set to be larger than the second sliding time window.

[0203] Calculate the mean v 1T With mean v 3T The third difference, and the mean v 2T With mean v 3T The fourth difference of ′,

[0204] Calculate the mean v of the third difference and the corrected first vehicle speed. 1T The first ratio p 1v ′, and the fourth difference and the mean v of the corrected second vehicle speed. 2T The second ratio p 2v ′,

[0205] Among them, the third difference and the mean of the corrected first vehicle speed, v 1T and the first ratio p 1v ′ satisfies the following relationship:

[0206]

[0207] Among them, abs(v 1T -v 3T The function is used to calculate (v) 1T -v 3T The absolute value of )

[0208] The fourth difference, the mean of the corrected second vehicle speed, v 2T And the second ratio p 2v ′ satisfies the following relationship:

[0209]

[0210] Among them, abs(v 2T -v 3T The function ') is used to calculate (v 2T -v 3T The absolute value of ′).

[0211] In one embodiment, the vehicle speed determination device 500 further includes a detection module.

[0212] The detection module is used to detect a target value as a first preset value when a first difference is greater than a preset threshold and / or a second difference is greater than a preset threshold. The first preset value represents an anomaly in the corrected third vehicle speed.

[0213] The determination module 504 is also used to determine the corrected second vehicle speed as the target vehicle speed.

[0214] In one embodiment, the detection module is further configured to detect a target value as a second preset value when a first ratio is less than or equal to a preset threshold and a second ratio is less than or equal to a preset threshold. The second preset value indicates that the corrected third vehicle speed is normal.

[0215] The determination module 504 is also used to determine the corrected third vehicle speed as the target vehicle speed.

[0216] In one embodiment, the determining module 504 is further configured to determine the corrected second vehicle speed as the target vehicle speed when the vehicle's wheel speed is a default value or when it is in a target state, wherein the target state is the state where the vehicle speed is zero when the vehicle is moving at low speed.

[0217] In one embodiment, the acquisition module 504 is further configured to acquire the differential GPS distance D of the differential GPS positioning system within a third sliding time window when the vehicle's operating state is detected as constant speed and straight-line travel. GPS and the target vehicle speed v out The vehicle mileage D is obtained by integral calculation. vThe third sliding time window is determined based on the minimum speed among the first, second, and third vehicle speeds.

[0218] The determination module 504 is also used to determine the vehicle's mileage D. v Differential GPS mobile mileage D GPS The ratio is determined as the vehicle speed error correction coefficient p. d ,

[0219] The correction module 502 is also used to correct the vehicle speed error based on the vehicle speed error correction coefficient p. d Correct target vehicle speed v out The corrected target vehicle speed v is obtained. final The corrected target vehicle speed v final Vehicle speed error correction coefficient p d and target vehicle speed v out The following relationship must be satisfied:

[0220] v final =v out / p d .

[0221] Therefore, by acquiring the vehicle's first, second, and third speeds under the target load, along with their corresponding speed correction coefficients, where the first speed is the chassis speed, and the second and third speeds are calculated based on the vehicle's transmission output shaft speed and wheel speed, respectively, the system corrects the first, second, and third speeds based on the speed correction coefficients. This allows for speed correction under different loads, reducing the impact of load on speed. Next, the system calculates the first difference between the corrected first and third speeds, and the second difference between the corrected second and third speeds. It also calculates the first ratio of the first difference to the corrected first speed, and the second ratio of the second difference to the corrected second speed. This allows for anomaly detection of the third speed calculated from the wheel speeds. If the first ratio is greater than a preset threshold, and / or the second ratio is greater than a preset threshold, the corrected second speed is determined as the target speed; that is, when the third speed is abnormal, the second speed is output as the target speed. When the first ratio is less than or equal to a preset threshold and the second ratio is less than or equal to a preset threshold, that is, when the third vehicle speed is normal, the third vehicle speed is output as the target vehicle speed, which improves the accuracy of vehicle speed and thus improves the accuracy and reliability of the high-precision positioning system.

[0222] Figure 6 A schematic diagram of the hardware structure of the electronic device provided in an embodiment of this application is shown.

[0223] An electronic device may include a processor 601 and a memory 602 storing computer program instructions.

[0224] Specifically, the processor 601 may include a central processing unit (CPU), an application-specific integrated circuit (ASIC), or one or more integrated circuits that can be configured to implement the embodiments of this application.

[0225] Memory 602 may include mass storage for data or instructions. For example, and not limitingly, memory 602 may include a hard disk drive (HDD), floppy disk drive, flash memory, optical disk, magneto-optical disk, magnetic tape, or Universal Serial Bus (USB) drive, or a combination of two or more of these. Where appropriate, memory 602 may include removable or non-removable (or fixed) media. Where appropriate, memory 602 may be internal or external to the integrated gateway disaster recovery device. In a particular embodiment, memory 602 is non-volatile solid-state memory.

[0226] Memory may include read-only memory (ROM), random access memory (RAM), disk storage media devices, optical storage media devices, flash memory devices, and electrical, optical, or other physical / tangible memory storage devices. Therefore, typically, memory includes one or more tangible (non-transitory) computer-readable storage media (e.g., memory devices) encoded with software including computer-executable instructions, and when the software is executed (e.g., by one or more processors), it is operable to perform the operations described with reference to the methods according to one aspect of this disclosure.

[0227] The processor 601 implements any of the vehicle speed determination methods in the above embodiments by reading and executing computer program instructions stored in the memory 602.

[0228] In one example, the electronic device may also include a communication interface 603 and a bus 610. For example, Figure 6 As shown, the processor 601, memory 602, and communication interface 603 are connected through bus 610 and complete communication with each other.

[0229] The communication interface 603 is mainly used to realize communication between various modules, devices, units and / or equipment in the embodiments of this application.

[0230] Bus 610 includes hardware, software, or both, that couples components of a device at a given speed together. For example, and not as a limitation, the bus may include an Accelerated Graphics Port (AGP) or other graphics bus, an Enhanced Industry Standard Architecture (EISA) bus, a Front Side Bus (FSB), HyperTransport (HT) interconnect, an Industry Standard Architecture (ISA) bus, an Infinite Bandwidth Interconnect, a Low Pin Count (LPC) bus, a memory bus, a Microchannel Architecture (MCA) bus, a Peripheral Component Interconnect (PCI) bus, a PCI-Express (PCI-X) bus, a Serial Advanced Technology Attachment (SATA) bus, a Video Electronics Standards Association Local (VLB) bus, or other suitable buses, or combinations of two or more of these. Where appropriate, bus 610 may include one or more buses. Although specific buses are described and illustrated in embodiments of this application, this application contemplates any suitable bus or interconnect.

[0231] This electronic device can execute the vehicle speed determination method in this application embodiment based on the first, second, and third vehicle speeds under the target load, and the corresponding speed correction coefficients, thereby achieving a combination of... Figure 1 The method described is for determining vehicle speed.

[0232] Furthermore, in conjunction with the vehicle speed determination method in the above embodiments, this application embodiment can provide a computer storage medium for implementation. The computer storage medium stores computer program instructions; when these computer program instructions are executed by a processor, they implement any of the vehicle speed determination methods in the above embodiments.

[0233] It should be clarified that this application is not limited to the specific configurations and processes described above and shown in the figures. For the sake of brevity, detailed descriptions of known methods are omitted here. In the above embodiments, several specific steps are described and shown as examples. However, the method process of this application is not limited to the specific steps described and shown. Those skilled in the art can make various changes, modifications, and additions, or change the order of steps, after understanding the spirit of this application.

[0234] The functional blocks shown in the above-described structural diagram can be implemented as hardware, software, firmware, or a combination thereof. When implemented in hardware, they can be, for example, electronic circuits, application-specific integrated circuits (ASICs), appropriate firmware, plug-ins, function cards, etc. When implemented in software, the elements of this application are programs or code segments used to perform the required tasks. Programs or code segments can be stored on a machine-readable medium or transmitted over a transmission medium or communication link via data signals carried on a carrier wave. "Machine-readable medium" can include any medium capable of storing or transmitting information. Examples of machine-readable media include electronic circuits, semiconductor memory devices, ROM, flash memory, erasable ROM (EROM), floppy disks, CD-ROMs, optical disks, hard disks, fiber optic media, radio frequency (RF) links, etc. Code segments can be downloaded via computer networks such as the Internet, intranets, etc.

[0235] It should also be noted that the exemplary embodiments mentioned in this application describe methods or systems based on a series of steps or apparatus. However, this application is not limited to the order of the above steps; that is, the steps can be performed in the order mentioned in the embodiments, or in a different order, or several steps can be performed simultaneously.

[0236] The aspects of this disclosure have been described above with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this disclosure. It should be understood that each block in the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing apparatus to produce a machine such that these instructions, executable via the processor of the computer or other programmable data processing apparatus, enable the implementation of the functions / actions specified in one or more blocks of the flowchart illustrations and / or block diagrams. Such a processor can be, but is not limited to, a general-purpose processor, a special-purpose processor, a special application processor, or a field-programmable logic circuit. It is also understood that each block in the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, can also be implemented by special-purpose hardware performing the specified functions or actions, or can be implemented by a combination of special-purpose hardware and computer instructions.

[0237] The above description is merely a specific implementation of this application. Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, modules, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here. It should be understood that the protection scope of this application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this application, and these modifications or substitutions should all be covered within the protection scope of this application.

Claims

1. A method of vehicle speed determination, characterized by, The method comprises: obtaining a first vehicle speed, a second vehicle speed, and a third vehicle speed of the vehicle under a target load, and speed correction coefficients corresponding to the first vehicle speed, the second vehicle speed, and the third vehicle speed under the target load, wherein the first vehicle speed is a chassis speed, the second vehicle speed is calculated according to a transmission output shaft speed of the vehicle, and the third vehicle speed is calculated according to a wheel speed of the vehicle, correcting the first vehicle speed, the second vehicle speed, and the third vehicle speed based on the speed correction coefficients corresponding to the first vehicle speed, the second vehicle speed, and the third vehicle speed respectively, calculating a first difference between the corrected first vehicle speed and the corrected third vehicle speed, and a second difference between the corrected second vehicle speed and the corrected third vehicle speed, calculating a first ratio of the first difference to the corrected first vehicle speed, and a second ratio of the second difference to the corrected second vehicle speed, in a case where the first ratio is greater than a preset threshold value and / or the second ratio is greater than the preset threshold value, determining the corrected second vehicle speed as a target vehicle speed, in a case where the first ratio is less than or equal to the preset threshold value and the second ratio is less than or equal to the preset threshold value, determining the corrected third vehicle speed as the target vehicle speed; before the obtaining, the method further comprises: obtaining a first vehicle speed, a second vehicle speed, a third vehicle speed, and a real vehicle speed of the vehicle under at least one load, wherein the at least one load comprises the target load, and the real vehicle speed is detected by a preset vehicle speed measurement system, for each load, determining a ratio of the first vehicle speed, the second vehicle speed, and the third vehicle speed to the real vehicle speed as a speed correction coefficient corresponding to the first vehicle speed, the second vehicle speed, and the third vehicle speed.

2. The method of claim 1, wherein, The first difference, the corrected first vehicle speed, and the first ratio satisfy the following relationship: wherein, is the modified first vehicle speed, the first difference, absolute value, The second difference, the corrected second vehicle speed, and the second ratio satisfy the following relationship: wherein, is the modified second vehicle speed, the second difference, absolute value.

3. The method of claim 1, wherein, The speed correction coefficient comprises an empty load vehicle speed calibration coefficient corresponding to the first vehicle speed, the second vehicle speed, and the third vehicle speed when the load is zero.

4. The method of claim 1, wherein, The first vehicle speed, the second vehicle speed, and the third vehicle speed comprise first vehicle speeds, second vehicle speeds, and third vehicle speeds obtained at a preset frequency, and the method further comprises: In a case where it is detected that the running state of the vehicle is uniform speed and straight driving, the average of the first vehicle speed in the first sliding time window is calculated and the average of the third vehicle speed after correction , and the average of the second vehicle speed in the second sliding time window after correction and the average of the third vehicle speed after correction , wherein the first sliding time window and the second sliding time window are respectively set according to the proportion error between the third vehicle speed anomaly and the true vehicle speed being within a preset range, and the first sliding time window is greater than the second sliding time window. Computing the mean With the mean And the mean With the mean , Calculate the average of the third difference and the corrected first vehicle speed. First ratio And the average of the fourth difference and the corrected second speed. Second ratio , wherein the third difference, the mean value of the corrected first vehicle speed and the first ratio satisfy the following relationship: wherein The function is used to calculate the absolute value of (x) ) the fourth difference value, the average of the corrected second vehicle speeds and the second ratio satisfies the following relationship: wherein The function is used to calculate the absolute value of (x). The function is used to calculate the absolute value of (x).

5. The method of claim 1, wherein, The determining the corrected second vehicle speed as the target vehicle speed in the case where the first difference is greater than a preset threshold value and / or the second difference is greater than the preset threshold value comprises: In the case where the first difference is greater than a preset threshold value and / or the second difference is greater than the preset threshold value, detecting that a target value is a first preset value, and the first preset value represents that the corrected third vehicle speed is abnormal, determining the corrected second vehicle speed as the target vehicle speed.

6. The method of claim 1, wherein, The determining the corrected third vehicle speed as the target vehicle speed in the case where the first ratio is less than or equal to a preset threshold value and the second ratio is less than or equal to the preset threshold value comprises: In a case where the first ratio is less than or equal to a preset threshold value and the second ratio is less than or equal to the preset threshold value, it is detected that the target value is a second preset value, and the second preset value represents a normal third speed after correction. It is determined that the corrected third speed is a target speed.

7. The method of claim 1, wherein, The method further comprises: In a case where the wheel speed of the vehicle is a default value or in a target state, the corrected second speed is determined as the target speed, and the target state is a state in which the vehicle speed is zero when the vehicle moves at a low speed.

8. The method according to any one of claims 1 to 7, characterized in that, The preset speed measurement system comprises a differential GPS positioning system, and the method further comprises: In a case where it is detected that the running state of the vehicle is uniform speed and straight driving, a differential GPS moving distance of the differential GPS positioning system in a third sliding time window is acquired , and a vehicle driving distance obtained by integrating the target vehicle speed is acquired , wherein the third sliding time window is determined according to the minimum speed among the first vehicle speed, the second vehicle speed and the third vehicle speed. determining a ratio of the vehicle mileage to the differential GPS travel mileage as a vehicle speed error correction coefficient , based on the vehicle speed error correction coefficient correcting the target vehicle speed , to obtain a corrected target vehicle speed , the corrected target vehicle speed , the vehicle speed error correction coefficient and the target vehicle speed satisfy the following relationship: 。 9. A device for determining a vehicle speed, characterized in that The device comprises: an acquisition module, configured to acquire a first speed, a second speed and a third speed of a vehicle under a target load, and speed correction coefficients corresponding to the first speed, the second speed and the third speed under the target load, wherein the first speed is a chassis speed, the second speed is calculated according to a transmission output shaft speed of the vehicle, and the third speed is calculated according to a wheel speed of the vehicle, a correction module, configured to correct the first speed, the second speed and the third speed based on the speed correction coefficients corresponding to the first speed, the second speed and the third speed, respectively, a calculation module, configured to calculate a first difference between the corrected first speed and the corrected third speed, and a second difference between the corrected second speed and the corrected third speed, the calculation module is further configured to calculate a first ratio of the first difference to the corrected first speed, and a second ratio of the second difference to the corrected second speed, a determination module, configured to determine the corrected second speed as a target speed in a case where the first ratio is greater than a preset threshold value and / or the second ratio is greater than the preset threshold value, the determination module is further configured to determine the corrected third speed as the target speed in a case where the first ratio is less than or equal to the preset threshold value and the second ratio is less than or equal to the preset threshold value; the acquisition module is further configured to acquire a first speed, a second speed, a third speed and a real speed of a vehicle under at least one load before acquiring the first speed, the second speed and the third speed of the vehicle under the target load, and the speed correction coefficients corresponding to the first speed, the second speed and the third speed under the target load, the real speed is detected by a preset speed measurement system, and the at least one load comprises the target load, the determination module is further configured to determine, for each load, a ratio of the first speed, the second speed and the third speed to the real speed as the speed correction coefficients corresponding to the first speed, the second speed and the third speed, respectively.

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