Method and apparatus for calculating vehicle speed

Abstract

This application discloses a method and apparatus for calculating vehicle speed. The method includes: obtaining a steering transmission ratio function between the steering wheel and the steering wheel angle, and the wheel speed of each wheel; converting the wheel speed of each wheel into an equivalent speed at a preset position of the vehicle based on the steering transmission ratio function and the wheel speed of each wheel; calculating data quality attributes of the equivalent speed of each wheel, wherein the data quality attributes include at least one of the following: consistency of equivalent speeds of two pairs of paired wheels in the front-rear direction; consistency of equivalent speeds of two pairs of paired wheels in the left-right direction; consistency of equivalent speeds of each wheel at both front and rear moments; and performing a weighted fusion calculation on the equivalent speeds of each wheel based on the data quality attributes to obtain a reference speed for the vehicle. Using this application embodiment can improve the accuracy of vehicle speed calculation.

Description

Technical Field

[0001] This application relates to the field of intelligent vehicle technology, and in particular to a method and apparatus for calculating vehicle speed. Background Technology

[0002] In existing automotive systems, vehicles are equipped with wheel speed sensors to measure wheel speed information. In the field of autonomous driving, wheel speed sensors are also used for online integrated real-time localization, mileage estimation, and offline trajectory generation for SLAM (Simultaneous Localization and Mapping). The vehicle's speed can be calculated from the wheel speed information by the inertial measurement unit (IMU). Therefore, the accuracy of the wheel speed measured by the wheel speed sensor is crucial for ensuring the accuracy of integrated localization. However, under certain conditions such as slippage, speed bumps, and cornering, the wheel speed sensor readings can be inaccurate, leading to inaccurate localization results. Therefore, how to address these specific conditions and obtain more accurate wheel speed information is a problem that urgently needs to be solved.

[0003] The driven wheel speed method is a commonly used method for calculating wheel speed. Since the driven wheel relies solely on ground friction for its driving force, it experiences free rolling. For the driven wheel, this wheel speed does not experience significant slippage due to strong acceleration or deceleration. However, while this method can accommodate slippage caused by acceleration and deceleration, it can introduce significant errors when encountering sudden changes in road conditions such as speed bumps or puddles due to the free rolling characteristics of the driven wheel. Furthermore, in real-world vehicles, the differential, which allows the left and right (or front and rear) drive wheels to rotate at different speeds during cornering, ensures that the drive wheels on both sides undergo pure rolling motion when the car is turning or driving on uneven surfaces. This redistributes wheel speeds, meaning the wheels and vehicle body cannot be simply considered rigid bodies. Therefore, the wheel speed of a single wheel as the vehicle's speed will inevitably deviate from the actual vehicle speed. Summary of the Invention

[0004] The technical problem to be solved by the embodiments of this application is to provide a method and apparatus for calculating vehicle speed, so as to solve the problem of inaccurate vehicle speed calculation under some driving conditions.

[0005] In a first aspect, embodiments of this application provide a method for calculating vehicle speed, which may include:

[0006] Obtain the steering gear ratio function between the steering wheel and the steering wheel angle, as well as the wheel speed of each wheel;

[0007] Based on the steering ratio function and the wheel speed of each wheel, the wheel speed of each wheel is converted into the equivalent speed of the vehicle at a preset position.

[0008] The data quality attributes for calculating the equivalent speed of each wheel include at least one of the following:

[0009] Consistency of equivalent speeds between the two sets of paired wheels in the front-rear direction;

[0010] The consistency of the equivalent speeds of the two sets of paired wheels in the left-right direction;

[0011] The consistency of the equivalent speed of each wheel at both the front and rear moments;

[0012] The equivalent speed of each wheel is weighted and fused based on the data quality attributes to obtain the reference speed of the car.

[0013] By introducing the concept of data quality attributes, the accuracy of the equivalent speed of each wheel can be clearly determined. This lays the foundation for the fusion of equivalent speeds of multiple wheels. Wheels with higher equivalent speed accuracy can be assigned higher weights, while wheels with lower equivalent speed accuracy can be assigned lower weights, thereby obtaining a more accurate vehicle reference speed and fully meeting the needs of vehicle speed measurement under different working conditions.

[0014] In one possible implementation, obtaining the steering gear ratio function between the drive wheel and the steering wheel angle includes:

[0015] Read the pre-stored steering ratio function from the vehicle's memory.

[0016] In one possible implementation, obtaining the steering gear ratio function between the steering wheel and the steering wheel angle includes:

[0017] The true vehicle speed is obtained by measuring the accuracy of a positioning device that is higher than that of a wheel speed meter;

[0018] The steering wheel angle is determined by the steering wheel angle and the true vehicle speed;

[0019] The steering ratio function is obtained by fitting the mapping data of the steering wheel angle and the steering wheel angle within a preset time period.

[0020] By obtaining the unknown steering ratio function through data fitting, the method for calculating vehicle speed in this application can be applied to various vehicles, thus improving its applicability and flexibility.

[0021] In one possible implementation, the data quality attribute is calculated using the following formula:

[0022]

[0023] Where t represents time, μ x α represents the consistency of the equivalent speeds of the two sets of paired wheels in the front-rear direction. y λ represents the consistency of the equivalent speeds of the two pairs of wheels in the left-right direction. xy This indicates the consistency of the equivalent speed of each wheel at the front and rear moments. fun represents a preset function. x = f(front) and r(rear) indicate that x takes the value of the front wheel or the rear wheel. y = l(left) and r(right) indicate that y takes the value of the left wheel or the right wheel.

[0024] By introducing data quality attributes, the wheel speed of each wheel can be evaluated from different dimensions, improving the flexibility of wheel speed data usage and ensuring the accuracy of multi-wheel speed fusion.

[0025] In one possible implementation, the preset function includes:

[0026] Find the reciprocal of the difference between the two parameters;

[0027] Alternatively, take the reciprocal of the difference of squares between the two parameters;

[0028] Alternatively, find the difference in exponents of the opposites of the two parameters.

[0029] By calculating data quality attributes using various functional relationships, the overall flexibility and applicability of the solution can be further improved.

[0030] In one possible implementation, when using the consistency μ of the equivalent speeds of the two sets of paired wheels in the front-rear direction... x When performing weighted fusion calculation, the step of weighted fusion calculation of the equivalent speed of each wheel based on the data quality attributes to obtain the reference speed of the vehicle includes:

[0031] Based on μ x The calculation method calculates the evaluation index μ for the front and rear wheel groups. f and μ r ;

[0032] According to the following formula, μ f and μ r Normalization process is performed to obtain and

[0033]

[0034] Compare and The magnitude of the value determines the confidence level of the front wheel group and the rear wheel group at the current moment, and the confidence level is positively correlated with the weights in the weighted fusion calculation;

[0035] The reference speed of a car can be calculated using the following formula:

[0036]

[0037] Among them, v output v represents the reference speed of the car. x This represents the equivalent speed of the wheel at its x-wheel speed when converted to the vehicle's preset position.

[0038] Calculating reference speed by using data quality attributes in the left and right directions can effectively improve the accuracy of reference speed calculation during turning.

[0039] In one possible implementation, when using the consistency μ of the equivalent speeds of the two sets of paired wheels in the front-rear direction... x ; and the consistency α of the equivalent speeds of the two sets of paired wheels in the left-right direction. y When performing weighted fusion calculation, the step of weighted fusion calculation of the equivalent speed of each wheel based on the data quality attributes to obtain the reference speed of the vehicle includes:

[0040] Based on μ x The calculation method calculates the evaluation index μ for the front and rear wheel groups. f and μ r ;

[0041] According to the following formula, μ f and μ r Normalization process is performed to obtain and

[0042]

[0043] Based on α y The calculation method calculates the evaluation index α for the left and right wheel groups. l and α r ;

[0044] According to the following formula, α1 and α r Normalization process is performed to obtain and

[0045]

[0046] According to the following formula Normalization is performed:

[0047]

[0048] Compare x and y under different values The magnitude of the value determines the confidence level of each wheel at the current moment, and the confidence level of each wheel is positively correlated with the weight in the weighted fusion calculation.

[0049] The reference speed of a car can be calculated using the following formula:

[0050]

[0051] Among them, v output v represents the reference speed of the car. xy This represents the equivalent speed of the wheel at its xy position when converted to the vehicle's preset position.

[0052] Calculating reference speed using two-dimensional data quality attributes can further improve the accuracy of reference speed calculation.

[0053] In one possible implementation, when using the consistency μ of the equivalent speeds of the two sets of paired wheels in the front-rear direction... x The consistency α of the equivalent speeds of the two sets of paired wheels in the left-right direction. y ; and the consistency λ of the equivalent velocity of each wheel at both the front and rear moments. xy When performing weighted fusion calculation, the step of weighted fusion calculation of the equivalent speed of each wheel based on the data quality attributes to obtain the reference speed of the vehicle includes:

[0054] Based on μ x The calculation method calculates the evaluation index μ for the front and rear wheel groups. f and μ r ;

[0055] According to the following formula, μ f and μ r Normalization process is performed to obtain and

[0056]

[0057] Based on α y The calculation method calculates the evaluation index α for the left and right wheel groups. l and α r ;

[0058] According to the following formula, α l and α r Normalization process is performed to obtain and

[0059]

[0060] Based on λ xy The calculation method calculates the evaluation index λ for each wheel at the current moment.xy, ;

[0061] λ is calculated according to the following formula. xy, Normalization process is performed to obtain

[0062]

[0063] According to the following formula Normalization is performed:

[0064]

[0065] Compare x, y, and i under different values The magnitude of the value determines the confidence level of each wheel at the current moment, and the confidence level of each wheel is positively correlated with the weight in the weighted fusion calculation.

[0066] The reference speed of a car can be calculated using the following formula:

[0067]

[0068] Among them, v output v represents the reference speed of the car. xy,i This represents the wheel speed xy at time i converted to the equivalent speed at the vehicle's preset position.

[0069] Calculating reference velocity using three-dimensional data quality attributes can further improve the accuracy of reference velocity calculation.

[0070] Secondly, embodiments of this application provide an apparatus for calculating vehicle speed, which may include:

[0071] The acquisition unit is used to acquire the steering transmission ratio function between the steering wheel and the steering wheel angle, as well as the wheel speed of each wheel;

[0072] The conversion unit is used to convert the wheel speed of each wheel into the equivalent speed of the vehicle at a preset position according to the steering transmission ratio function and the wheel speed of each wheel.

[0073] A calculation unit is used to calculate the data quality attributes of the equivalent speed of each wheel, wherein the data quality attributes include at least one of the following:

[0074] Consistency of equivalent speeds between the two sets of paired wheels in the front-rear direction;

[0075] The consistency of the equivalent speeds of the two sets of paired wheels in the left-right direction;

[0076] The consistency of the equivalent speed of each wheel at both the front and rear moments;

[0077] The equivalent speed of each wheel is weighted and fused based on the data quality attributes to obtain the reference speed of the car.

[0078] In one possible implementation, the acquisition unit specifically includes:

[0079] Read the pre-stored steering ratio function from the vehicle's memory.

[0080] In one possible implementation, the acquisition unit is specifically used for:

[0081] The true vehicle speed is obtained by measuring the accuracy of a positioning device that is higher than that of a wheel speed meter;

[0082] The steering wheel angle is determined by the steering wheel angle and the true vehicle speed;

[0083] The steering ratio function is obtained by fitting the mapping data of the steering wheel angle and the steering wheel angle within a preset time period.

[0084] In one possible implementation, the data quality attribute is calculated using the following formula:

[0085]

[0086] Where t represents time, μ x α represents the consistency of the equivalent speeds of the two sets of paired wheels in the front-rear direction. y λ represents the consistency of the equivalent speeds of the two pairs of wheels in the left-right direction. xy This indicates the consistency of the equivalent speed of each wheel at the front and rear moments. fun represents a preset function. x = f(front) and r(rear) indicate that x takes the value of the front wheel or the rear wheel. y = l(left) and r(right) indicate that y takes the value of the left wheel or the right wheel.

[0087] In one possible implementation, the preset function includes:

[0088] Find the reciprocal of the difference between the two parameters;

[0089] Alternatively, take the reciprocal of the difference of squares between the two parameters;

[0090] Alternatively, find the difference in exponents of the opposites of the two parameters.

[0091] In one possible implementation, when using the consistency μ of the equivalent speeds of the two sets of paired wheels in the front-rear direction... x When performing weighted fusion calculations, the calculation unit is specifically used for:

[0092] Based on μ x The calculation method calculates the evaluation index μ for the front and rear wheel groups. fand μ r ;

[0093] According to the following formula, μ f and μ r Normalization process is performed to obtain and

[0094]

[0095] Compare and The magnitude of the value determines the confidence level of the front wheel group and the rear wheel group at the current moment, and the confidence level is positively correlated with the weights in the weighted fusion calculation;

[0096] The reference speed of a car can be calculated using the following formula:

[0097]

[0098] Among them, v output v represents the reference speed of the car. x This represents the equivalent speed of the wheel at its x-wheel speed when converted to the vehicle's preset position.

[0099] In one possible implementation, when using the consistency μ of the equivalent speeds of the two sets of paired wheels in the front-rear direction... x ; and the consistency α of the equivalent speeds of the two sets of paired wheels in the left-right direction. y When performing weighted fusion calculations, the calculation unit is specifically used for:

[0100] Based on μ x The calculation method calculates the evaluation index μ for the front and rear wheel groups. f and μ r ;

[0101] According to the following formula, μ f and μ r Normalization process is performed to obtain and

[0102]

[0103] Based on α y The calculation method calculates the evaluation index α for the left and right wheel groups. l and α r ;

[0104] According to the following formula, α l and α r Normalization process is performed to obtain and

[0105]

[0106] According to the following formula Normalization is performed:

[0107]

[0108] Compare x and y under different values The magnitude of the value determines the confidence level of each wheel at the current moment, and the confidence level of each wheel is positively correlated with the weight in the weighted fusion calculation.

[0109] The reference speed of a car can be calculated using the following formula:

[0110]

[0111] Among them, v output v represents the reference speed of the car. xy This represents the equivalent speed of the wheel at its xy position when converted to the vehicle's preset position.

[0112] In one possible implementation, when using the consistency μ of the equivalent speeds of the two sets of paired wheels in the front-rear direction... x The consistency α of the equivalent speeds of the two sets of paired wheels in the left-right direction. y ; and the consistency λ of the equivalent velocity of each wheel at both the front and rear moments. xy When performing weighted fusion calculations, the calculation unit is specifically used for:

[0113] Based on μ x The calculation method calculates the evaluation index μ for the front and rear wheel groups. f and μ r ;

[0114] According to the following formula, μ f and μ r Normalization process is performed to obtain and

[0115]

[0116] Based on α y The calculation method calculates the evaluation index α for the left and right wheel groups. l and α r ;

[0117] According to the following formula, α l and α r Normalization process is performed to obtain and

[0118]

[0119] Based on λ xy The calculation method calculates the evaluation index λ for each wheel at the current moment. xy,i ;

[0120] λ is calculated according to the following formula. xy,i Normalization process is performed to obtain

[0121]

[0122] According to the following formula Normalization is performed:

[0123]

[0124] Compare x, y, and i under different values The magnitude of the value determines the confidence level of each wheel at the current moment, and the confidence level of each wheel is positively correlated with the weight in the weighted fusion calculation.

[0125] The reference speed of a car can be calculated using the following formula:

[0126]

[0127] Among them, v output v represents the reference speed of the car. xy,i This represents the wheel speed xy at time i converted to the equivalent speed at the vehicle's preset position.

[0128] In one possible implementation, the device is an inertial measurement unit installed on the vehicle.

[0129] Thirdly, an apparatus is provided. The apparatus provided in this application functions to perform the actions of the device for calculating vehicle speed as described in the above-described method aspects, and includes means for performing steps or functions corresponding to those described in the above-described method aspects. These steps or functions can be implemented by software, hardware (such as circuitry), or a combination of both.

[0130] In one possible design, the aforementioned device includes one or more processors and a communication unit. The one or more processors are configured to support the device in performing the corresponding functions of the device for calculating vehicle speed in the above method. For example, acquiring the steering gear ratio function between the steering wheel and the steering wheel angle, and the wheel speeds of each wheel. Based on the steering gear ratio function and the wheel speeds of each wheel, converting the wheel speeds of each wheel into equivalent speeds at a preset position of the vehicle; calculating the data quality attributes of the equivalent speeds of each wheel; and performing a weighted fusion calculation on the equivalent speeds of each wheel based on the data quality attributes to obtain a reference speed for the vehicle. The communication unit is used to support the device in communicating with other devices, realizing receiving and / or transmitting functions. For example, sending the calculated reference speed to an onboard terminal, and receiving raw data collected by various sensors, etc.

[0131] Optionally, the device may further include one or more memories coupled to the processor, which store program instructions and / or data necessary for the device. The one or more memories may be integrated with the processor or disposed separately from the processor. This application is not limiting.

[0132] The device can be an inertial measurement unit, a vehicle-mounted terminal, etc., and the communication unit can be a transceiver or a transceiver circuit. Optionally, the transceiver can also be an input / output circuit or an interface.

[0133] The device can also be a chip. The communication unit can be the chip's input / output circuitry or interface.

[0134] In another possible design, the aforementioned device includes a processor and a memory for storing a computer program, and the processor for running the computer program in the memory, causing the device to perform the method of calculating vehicle speed as described in the first aspect or any possible implementation of the first aspect.

[0135] Fourthly, a system is provided that includes the aforementioned device and at least two wheel speed meters for measuring wheel speeds.

[0136] Fifthly, a computer-readable storage medium is provided for storing a computer program including instructions for performing the methods of the first aspect or any possible implementation thereof.

[0137] In a sixth aspect, a computer program product is provided, the computer program product comprising: computer program code, which, when executed on a processor, implements the method in the first aspect or any possible implementation of the first aspect.

[0138] In a seventh aspect, a chip is provided, comprising one or more processing circuits, wherein the one or more processing circuits are configured to implement the method of the first aspect or any possible implementation thereof. Attached Figure Description

[0139] Figure 1 A schematic diagram of an architecture for calculating vehicle speed provided in an embodiment of this application;

[0140] Figure 2 A flowchart illustrating a method for calculating vehicle speed provided in an embodiment of this application;

[0141] Figure 3 A flowchart illustrating another method for calculating vehicle speed provided in an embodiment of this application;

[0142] Figure 4 A flowchart illustrating another method for calculating vehicle speed provided in an embodiment of this application;

[0143] Figure 5 A flowchart illustrating another method for calculating vehicle speed provided in an embodiment of this application;

[0144] Figure 6 A schematic diagram comparing the effect of the vehicle speed calculation method provided in this application embodiment with other calculation methods under continuous speed bump conditions;

[0145] Figure 7 A schematic diagram comparing the effect of the vehicle speed calculation method provided in this application embodiment with other calculation methods under continuous steering conditions;

[0146] Figure 8 A schematic diagram illustrating the composition of a device for calculating vehicle speed, provided in an embodiment of this application;

[0147] Figure 9 A schematic diagram of another device for calculating vehicle speed provided in an embodiment of this application. Detailed Implementation

[0148] The embodiments of this application will now be described with reference to the accompanying drawings.

[0149] The terms "comprising" and "having," and any variations thereof, in the specification, claims, and accompanying drawings of this application are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the steps or units listed, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to such process, method, product, or apparatus.

[0150] The method and apparatus for calculating vehicle speed according to embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0151] Please refer to Figure 1 This is a schematic diagram of a vehicle speed calculation architecture according to an embodiment of the present invention. It may include:

[0152] Wheels 10, wheel speedometer 20, steering wheel 30, inertial measurement unit 40.

[0153] The vehicle has four wheels 10: a left front wheel and a right rear wheel closer to the steering wheel 30, and a left rear wheel and a right rear wheel further away from the steering wheel. Since the vehicle's drive type can include front-wheel drive, rear-wheel drive, and four-wheel drive, the drive wheels can be either the front wheels or the rear wheels. This embodiment uses the front wheels as an example for description; the process is similar when the drive wheels are the rear wheels.

[0154] Wheel speed meter 20 is used to collect the raw wheel speed data of wheel 10. Generally, one corresponding wheel speed meter 20 is configured in the axle of each wheel.

[0155] The steering wheel 30 is used to control the vehicle's direction, and it has a certain steering ratio function with the drive wheels, i.e., the steering wheels. For different vehicles, the steering ratio function can be a linear function or a higher-order function.

[0156] An inertial measurement unit 40 is a device used to measure the three-axis attitude angles (or angular rates) and acceleration of an object. To improve reliability, more sensors can be equipped for each axis. Typically, the inertial measurement unit 40 can be mounted at the center of gravity of the object being measured. The inertial measurement unit 40 is commonly used in devices requiring motion control, such as automobiles and robots. It can also be used in applications requiring precise displacement calculations based on attitude, such as inertial navigation equipment for submarines, aircraft, missiles, and spacecraft. In this embodiment, the inertial measurement unit 40 can collect the wheel speeds of each wheel through the wheel speed meter 20 and convert these wheel speeds into equivalent speeds at the position of the inertial measurement unit 40. Then, the data quality attributes of the equivalent speeds of each wheel are calculated. These data quality attributes are mainly related to the consistency of the equivalent speeds of a particular wheel with those of other wheels, and / or the consistency of the equivalent speeds of a particular wheel at different times. Finally, the equivalent speeds of each vehicle are weighted and fused according to the data quality attributes to obtain the vehicle's reference speed.

[0157] For detailed procedures, please refer to [link / document / etc.]. Figures 2-4 A detailed introduction.

[0158] Please see Figure 2 , Figure 2 A flowchart illustrating a method for calculating vehicle speed provided in this application embodiment; specifically including the following steps:

[0159] S201. Obtain the steering transmission ratio function between the steering wheel and the steering wheel angle, as well as the wheel speed of each wheel.

[0160] Optionally, for some vehicles with known steering ratio functions, the steering ratio functions can be read from and used in memory.

[0161] For some vehicles with a steering gear ratio function, the steering gear ratio function can be estimated and calculated.

[0162] Positioning devices with higher accuracy than wheel speed meters, such as those using Global Navigation Satellite System (GNSS), Real-time Kinematic (RTK), or Inertial Navigation System (INS), can be used to measure positioning and speed information that can be used as reference values ​​for true positioning and true vehicle speed.

[0163] The steering wheel angle is determined by the steering wheel angle and the true vehicle speed;

[0164] For example, the true vehicle speed can be back-derived to the steering wheel through existing vehicle dynamics transformations, and the steering wheel angle under the current operating conditions can be solved.

[0165] Then, the steering ratio function is obtained by fitting the mapping data of the steering wheel angle and the steering wheel angle within a preset time period.

[0166] That is, by fitting multiple data over a period of time, a fitting curve and a steering ratio function can be obtained.

[0167] S202. Based on the steering transmission ratio function and the wheel speed of each wheel, convert the wheel speed of each wheel into the equivalent speed of the vehicle at a preset position.

[0168] The preset position here can be the center position of the car, where the inertial measurement unit 40 can be configured.

[0169] S203. Calculate the data quality attributes of the equivalent speed of each wheel.

[0170] Because the wheel speeds of different vehicles may vary under different operating conditions—for example, when encountering a speed bump, the front wheels may have already decelerated, while the rear wheels may have a higher wheel speed—or, during a turn, the wheel speeds of the left and right wheels may differ, as may the wheel speeds of the front and rear wheels. Therefore, conventional methods for calculating vehicle speed based on individual wheels have low accuracy. In this embodiment, a feature characterizing the accuracy of the wheel's equivalent speed can be assigned to the equivalent speed of each wheel.

[0171] Specifically, this may include, but is not limited to:

[0172] Consistency of equivalent speeds between the two sets of paired wheels in the front-rear direction;

[0173] The consistency of the equivalent speeds of the two sets of paired wheels in the left-right direction;

[0174] The consistency of the equivalent speed of each wheel at the front and rear moments.

[0175] Of course, it could also be the consistency of the equivalent speeds of the left front wheel and the right rear wheel, or the consistency of the equivalent speeds of the right front wheel and the left rear wheel.

[0176] Optionally, the data quality attribute is calculated using the following formula:

[0177]

[0178] Where t represents time, μ x α represents the consistency of the equivalent speeds of the two sets of paired wheels in the front-rear direction. y λ represents the consistency of the equivalent speeds of the two pairs of wheels in the left-right direction. xy This indicates the consistency of the equivalent speed of each wheel at the front and rear moments. fun represents a preset function. x = f(front) and r(rear) indicate that x takes the value of the front wheel or the rear wheel. y = l(left) and r(right) indicate that y takes the value of the left wheel or the right wheel.

[0179] The preset function may include, but is not limited to:

[0180] Find the reciprocal of the difference between the two parameters; that is, fun(a, b) = 1 / (ab).

[0181] Alternatively, take the reciprocal of the difference of squares between the two parameters; that is, fun(a, b) = 1 / (a...). 2 -b 2 ).

[0182] Alternatively, we can find the exponential difference between the opposites of the two parameters; that is, fun(a, b) = (-a) x -(-b) x .

[0183] S204. The equivalent speed of each wheel is weighted and fused according to the data quality attributes to obtain the reference speed of the car.

[0184] In this embodiment, by introducing the concept of data quality attributes, the accuracy of the equivalent speed of each wheel can be clearly determined. This lays the foundation for the fusion of equivalent speeds of multiple wheels. Wheels with higher equivalent speed accuracy can be assigned higher weights, while wheels with lower equivalent speed accuracy can be assigned lower weights, thereby obtaining a more accurate vehicle reference speed.

[0185] Please see Figure 3 , Figure 3 A flowchart illustrating another method for calculating vehicle speed provided in this application embodiment; in this embodiment, a one-dimensional data quality attribute is used to calculate the vehicle reference speed, such as the consistency μ of the equivalent speeds of two sets of paired wheels in the front-rear direction. x A weighted fusion calculation is performed to obtain a reference speed. This includes the following steps:

[0186] S301. Based on μ x The calculation method calculates the evaluation index μ for the front and rear wheel groups. f and μ r .

[0187] S302. Put μ f and μ r Normalization process is performed to obtain and

[0188] Specifically, it can be done according to the following formula:

[0189]

[0190] S303. Comparison and The magnitude of the value determines the confidence level of the front wheel group and the rear wheel group at the current moment, and the confidence level is positively correlated with the weights in the weighted fusion calculation.

[0191] S304. Calculate the reference speed of a vehicle based on one-dimensional data quality attributes.

[0192] The reference speed of a car can be calculated using the following formula:

[0193]

[0194] Among them, v output v represents the reference speed of the car. x This represents the equivalent speed of the wheel at its x-wheel speed when converted to the vehicle's preset position.

[0195] In this embodiment, the consistency μ of the equivalent speed of the two sets of paired wheels in the forward and backward direction is considered in a single dimension. x The weighted fusion calculation is used for explanation; alternatively, the consistency α of the equivalent speed of the two pairs of paired wheels can be considered in a single dimension, the left-right direction. y Weighted fusion calculations can also be performed using the consistency λ of the equivalent speed at each wheel's front and rear moments in a single dimension. xy The weighted fusion calculation is performed, and the specific calculation process is similar, so it will not be repeated here.

[0196] When using data quality attributes in the left-right direction for calculation, the problem of inaccurate vehicle speed calculation under turning conditions can be effectively avoided, thus improving the accuracy of vehicle speed calculation. When using data quality attributes in the front-back direction for calculation, the problem of inaccurate vehicle speed calculation under speed bump conditions can be effectively avoided, thus improving the accuracy of vehicle speed calculation. Furthermore, when using data quality attributes for each vehicle at each front-back moment for calculation, the problem of inaccurate vehicle speed calculation under special ground conditions such as water accumulation or potholes can be effectively avoided, thus improving the accuracy of vehicle speed calculation.

[0197] Please refer to Figure 4 , Figure 4 This is a flowchart illustrating another method for calculating vehicle speed provided in an embodiment of this application; in this embodiment, a two-dimensional data quality attribute is used to calculate the vehicle reference speed, and the consistency μ of the equivalent speeds of two sets of paired wheels in the front-rear direction is used. x ; and the consistency α of the equivalent speeds of the two sets of paired wheels in the left-right direction. y A weighted fusion calculation is performed to obtain the reference speed. S401-S402 and... Figure 3 Similar to S301-S302, they will not be repeated here. After S402, the following steps are also included:

[0198] S403. Based on α y The calculation method calculates the evaluation index α for the left and right wheel groups. l and α r .

[0199] S404. α l and α r Normalization process is performed to obtain and

[0200] The specific calculation can be performed using the following formula:

[0201]

[0202] S405. Will Normalization is performed.

[0203] The specific calculation can be performed using the following formula:

[0204]

[0205] S406. Compare x and y under different values. The magnitude of the value determines the confidence level of each wheel at the current moment, and the confidence level of each wheel is positively correlated with the weight in the weighted fusion calculation.

[0206] S407. Calculate the reference speed of a vehicle based on two-dimensional data quality attributes.

[0207] The reference speed of a car can be calculated using the following formula:

[0208]

[0209] Among them, v output v represents the reference speed of the car. xy This represents the equivalent speed of the wheel at its xy position when converted to the vehicle's preset position.

[0210] This embodiment uses data quality attributes in the left-right direction and the front-back direction to calculate the reference speed as an example. Of course, it is also possible to use the data quality attributes in the left-right direction and the data quality attributes at each wheel's front-back moment for a two-dimensional combined calculation, or to use the data quality attributes in the front-back direction and the data quality attributes at each vehicle's front-back moment for a two-dimensional combined calculation. The specific calculation methods are similar and will not be elaborated here. When using two-dimensional data quality attributes to calculate the reference speed, the accuracy of the reference speed calculation can be further improved.

[0211] Please see Figure 5 , Figure 5 A flowchart illustrating another method for calculating vehicle speed provided in this application embodiment; in this embodiment, a three-dimensional data quality attribute is used to calculate the vehicle reference speed, that is, the consistency μ of the equivalent speeds of two sets of paired wheels in the front-rear direction is used. x The consistency α of the equivalent speeds of the two sets of paired wheels in the left-right direction. y ; and the consistency λ of the equivalent velocity of each wheel at both the front and rear moments. xy A weighted fusion calculation is performed to obtain the reference speed. S501-S504 and... Figure 4 Similar to S401-S404, they will not be repeated here. After S504, the following steps are also included:

[0212] S505. Based on λ xy The calculation method calculates the evaluation index λ for each wheel at the current moment. xy,i .

[0213] S506. λ xy,i Normalization process is performed to obtain

[0214] Specifically, it can be done according to the following formula:

[0215]

[0216] S507. Normalization is performed.

[0217] Specifically, it can be done according to the following formula:

[0218]

[0219] S508. Compare x, y, and i under different values. The magnitude of the value determines the confidence level of each wheel at the current moment, and the confidence level of each wheel is positively correlated with the weight in the weighted fusion calculation.

[0220] S509. Calculate the reference speed of a vehicle based on three-dimensional data quality attributes.

[0221] The reference speed of a car can be calculated using the following formula:

[0222]

[0223] Among them, v output v represents the reference speed of the car. xy,i This represents the wheel speed xy at time i converted to the equivalent speed at the vehicle's preset position.

[0224] It should be noted that, in Figures 3-5 In the illustrated embodiments, data quality attributes of different dimensions are used to calculate the reference speed. Generally, the more dimensions of data quality attributes used, the more accurate the calculated reference speed, but the greater the computational load. Therefore, the dimensions of the data quality attributes can be flexibly selected based on factors such as the output efficiency of the reference speed and the processing power of the inertial measurement unit. For example, if a car's reference speed needs to be obtained quickly for positioning, a one-dimensional data quality attribute can be used to calculate the reference speed; if a higher precision car speed is required, a three-dimensional data quality attribute can be used to calculate the reference speed. This application does not impose any limitations on these embodiments.

[0225] Please refer to Figure 6 This is a schematic diagram comparing the effect of the vehicle speed calculation method provided in this application embodiment with other calculation methods under continuous speed bump conditions.

[0226] Wherein, the horizontal axis represents time, and the vertical axis represents speed. The solid line vel_ref represents the first reference speed projected into the current coordinate system (inertial measurement unit coordinate system) by the true vehicle speed obtained from other high-precision positioning devices. The equally spaced dashed lines vel_fusion represent the second reference speed projected into the current coordinate system by the reference speed obtained by multi-wheel speed fusion calculation in this embodiment. The non-equally spaced dashed lines vel_rr represent the third reference speed projected into the current coordinate system by the reference speed obtained by calculating the wheel speed using only the right rear wheel.

[0227] It is evident that the curve of the second reference speed vel_fusion obtained using this application is smoother than the curve of the third reference speed, and is closer to the curve of the first reference speed obtained by projecting the true vehicle speed from other high-precision positioning devices. Therefore, the vehicle speed information obtained by this application is more accurate under this condition, and can complement the speed information from other high-precision positioning devices for combined positioning and navigation.

[0228] Please refer to Figure 7 This is a schematic diagram comparing the effect of the vehicle speed calculation method provided in this application embodiment with other calculation methods under continuous steering conditions.

[0229] In this coordinate system, the horizontal axis represents time, and the vertical axis represents velocity. The solid line vel_ref represents the first reference velocity projected into the current coordinate system (inertial measurement unit coordinate system) by the true vehicle speed obtained from other high-precision positioning devices. The equally spaced dashed lines vel_fusion represent the second reference velocity projected into the current coordinate system by the reference velocity obtained by multi-wheel speed fusion calculation in this embodiment. The non-equally spaced dashed lines vel_rr represent the third reference velocity projected into the current coordinate system by the reference velocity obtained by calculating only the right rear wheel speed.

[0230] It is evident that the curve of the second reference speed vel_fusion obtained using this application is smoother than the curve of the third reference speed, and is closer to the curve of the first reference speed obtained by projecting the true vehicle speed from other high-precision positioning devices. Therefore, the vehicle speed information obtained by this application is more accurate under this condition, and can complement the speed information from other high-precision positioning devices for combined positioning and navigation.

[0231] Please refer to Figure 8 This is a schematic diagram illustrating the composition of a device for calculating vehicle speed according to an embodiment of this application. It may include:

[0232] The acquisition unit 100 is used to acquire the steering transmission ratio function between the steering wheel and the steering wheel angle, as well as the wheel speed of each wheel;

[0233] The conversion unit 200 is used to convert the wheel speed of each wheel into the equivalent speed of the vehicle at a preset position according to the steering transmission ratio function and the wheel speed of each wheel.

[0234] The calculation unit 300 is used to calculate the data quality attributes of the equivalent speed of each wheel, wherein the data quality attributes include at least one of the following:

[0235] Consistency of equivalent speeds between the two sets of paired wheels in the front-rear direction;

[0236] The consistency of the equivalent speeds of the two sets of paired wheels in the left-right direction;

[0237] The consistency of the equivalent speed of each wheel at both the front and rear moments;

[0238] The equivalent speed of each wheel is weighted and fused based on the data quality attributes to obtain the reference speed of the car.

[0239] Optionally, the acquisition unit 100 specifically includes:

[0240] Read the pre-stored steering ratio function from the vehicle's memory.

[0241] Optionally, the acquisition unit 100 is specifically used for:

[0242] The true vehicle speed is obtained by measuring the accuracy of a positioning device that is higher than that of a wheel speed meter;

[0243] The steering wheel angle is determined by the steering wheel angle and the true vehicle speed;

[0244] The steering ratio function is obtained by fitting the mapping data of the steering wheel angle and the steering wheel angle within a preset time period.

[0245] Optionally, the data quality attribute is calculated using the following formula:

[0246]

[0247] Where t represents time, μ x α represents the consistency of the equivalent speeds of the two sets of paired wheels in the front-rear direction. y λ represents the consistency of the equivalent speeds of the two pairs of wheels in the left-right direction. xyThis indicates the consistency of the equivalent speed of each wheel at the front and rear moments. fun represents a preset function. x = f(front) and r(rear) indicate that x takes the value of the front wheel or the rear wheel. y = l(left) and r(right) indicate that y takes the value of the left wheel or the right wheel.

[0248] Optionally, the preset function includes:

[0249] Find the reciprocal of the difference between the two parameters;

[0250] Alternatively, take the reciprocal of the difference of squares between the two parameters;

[0251] Alternatively, find the difference in exponents of the opposites of the two parameters.

[0252] Optionally, when using the longitudinal direction, the consistency μ of the equivalent speed of the two sets of paired wheels. x When performing weighted fusion calculations, the calculation unit 300 is specifically used for:

[0253] Based on μ x The calculation method calculates the evaluation index μ for the front and rear wheel groups. f and μ r ;

[0254] According to the following formula, μ f and μ r Normalization process is performed to obtain and

[0255]

[0256] Compare and The magnitude of the value determines the confidence level of the front wheel group and the rear wheel group at the current moment, and the confidence level is positively correlated with the weights in the weighted fusion calculation;

[0257] The reference speed of a car can be calculated using the following formula:

[0258]

[0259] Among them, v output v represents the reference speed of the car. x This represents the equivalent speed of the wheel at its x-wheel speed when converted to the vehicle's preset position.

[0260] Optionally, when using the longitudinal direction, the consistency μ of the equivalent speed of the two sets of paired wheels. x ; and the consistency α of the equivalent speeds of the two sets of paired wheels in the left-right direction. y When performing weighted fusion calculations, the calculation unit 300 is specifically used for:

[0261] Based on μ xThe calculation method calculates the evaluation index μ for the front and rear wheel groups. f and μ r ;

[0262] According to the following formula, μ f and μ r Normalization process is performed to obtain and

[0263]

[0264] Based on α y The calculation method calculates the evaluation index α for the left and right wheel groups. l and α r ;

[0265] According to the following formula, α l and α r Normalization process is performed to obtain and

[0266]

[0267] According to the following formula Normalization is performed:

[0268]

[0269] Compare x and y under different values The magnitude of the value determines the confidence level of each wheel at the current moment, and the confidence level of each wheel is positively correlated with the weight in the weighted fusion calculation.

[0270] The reference speed of a car can be calculated using the following formula:

[0271]

[0272] Among them, v output v represents the reference speed of the car. xy This represents the equivalent speed of the wheel at its xy position when converted to the vehicle's preset position.

[0273] Optionally, when using the longitudinal direction, the consistency μ of the equivalent speed of the two sets of paired wheels. x The consistency α of the equivalent speeds of the two sets of paired wheels in the left-right direction. y ; and the consistency λ of the equivalent velocity of each wheel at both the front and rear moments. xy When performing weighted fusion calculations, the calculation unit 300 is specifically used for:

[0274] Based on μ x The calculation method calculates the evaluation index μ for the front and rear wheel groups.f and μ r ;

[0275] According to the following formula, μ f and μ r Normalization process is performed to obtain and

[0276]

[0277] Based on α y The calculation method calculates the evaluation index α for the left and right wheel groups. l and α r ;

[0278] According to the following formula, α l and α r Normalization process is performed to obtain and

[0279]

[0280] Based on λ xy The calculation method calculates the evaluation index λ for each wheel at the current moment. xy,i ;

[0281] λ is calculated according to the following formula. xy，i Normalization process is performed to obtain

[0282]

[0283] According to the following formula Normalization is performed:

[0284]

[0285] Compare x, y, and i under different values The magnitude of the value determines the confidence level of each wheel at the current moment, and the confidence level of each wheel is positively correlated with the weight in the weighted fusion calculation.

[0286] The reference speed of a car can be calculated using the following formula:

[0287]

[0288] Among them, v output v represents the reference speed of the car. xy,i This represents the wheel speed xy at time i converted to the equivalent speed at the vehicle's preset position.

[0289] In one possible implementation, the device is an inertial measurement unit installed on the vehicle.

[0290] For the concepts, explanations, detailed descriptions, and other steps related to the technical solutions provided in the embodiments of this application, please refer to the descriptions of these contents in the foregoing methods or other embodiments, which will not be repeated here.

[0291] Please refer to Figure 9 This is a schematic diagram illustrating the composition of another device for calculating vehicle speed provided in an embodiment of this application; as shown below. Figure 9 As shown, the device may include a processor 110, a memory 120, and a bus 130. The processor 110 and the memory 120 are connected via the bus 130. The memory 120 is used to store instructions, and the processor 110 is used to execute the instructions stored in the memory 120 to achieve the above. Figures 2-5 The steps in the corresponding method.

[0292] Furthermore, the device may also include an input port 140 and an output port 150. The processor 110, memory 120, input port 140, and output port 150 can be connected via a bus 130.

[0293] The processor 110 executes the instructions stored in the memory 120 to control the input port 140 to receive signals and the output port 150 to send signals, thus completing the steps performed by the device in the above method. The input port 140 and the output port 150 can be the same or different physical entities. When they are the same physical entity, they can be collectively referred to as input / output ports. The memory 120 can be integrated into the processor 110 or can be disposed separately from the processor 110.

[0294] As one implementation method, the functions of input port 140 and output port 150 can be implemented using transceiver circuits or dedicated transceiver chips. Processor 110 can be implemented using dedicated processing chips, processing circuits, processors, or general-purpose chips.

[0295] As another implementation method, the apparatus provided in the embodiments of this application can be implemented using a general-purpose computer. The program code that implements the functions of processor 110, input port 140, and output port 150 is stored in memory, and the general-purpose processor implements the functions of processor 110, input port 140, and output port 150 by executing the code in memory.

[0296] For the concepts, explanations, detailed descriptions, and other steps related to the technical solutions provided in the embodiments of this application, please refer to the descriptions of these contents in the foregoing methods or other embodiments, which will not be repeated here.

[0297] Those skilled in the art will understand that, for ease of explanation, Figure 9Only one memory and processor are shown in the illustration. In a real controller, multiple processors and memories may exist. Memory can also be referred to as storage medium or storage device, etc., and this application does not limit this terminology.

[0298] It should be understood that in the embodiments of this application, the processor may be a central processing unit (CPU), or it may be other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc.

[0299] The memory may include read-only memory and random access memory, and provides instructions and data to the processor. A portion of the memory may also include non-volatile random access memory.

[0300] In addition to the data bus, this bus may also include a power bus, a control bus, and a status signal bus. However, for clarity, all buses are labeled "bus" in the diagram.

[0301] In implementation, each step of the above method can be completed by integrated logic circuits in the processor's hardware or by instructions in software. The steps of the method disclosed in the embodiments of this application can be directly implemented by a hardware processor, or by a combination of hardware and software modules in the processor. The software modules can reside in random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, registers, or other mature storage media in the art. This storage medium is located in memory, and the processor reads information from the memory and, in conjunction with its hardware, completes the steps of the above method. To avoid repetition, detailed descriptions are omitted here.

[0302] According to the method provided in the embodiments of this application, the embodiments of this application also provide a system, which includes the aforementioned device and at least two wheel speed gauges, etc.

[0303] In the various embodiments of this application, the order of the above-mentioned processes does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0304] Those skilled in the art will recognize that the various illustrative logical blocks (ILBs) and steps described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of this application.

[0305] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.

[0306] In the above embodiments, implementation can be achieved entirely or partially through software, hardware, firmware, or any combination thereof. When implemented using software, it can be implemented entirely or partially in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments of this application are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., coaxial cable, fiber optic, digital subscriber line) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or data center that integrates one or more available media. The available medium can be a magnetic medium (e.g., floppy disk, hard disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium (e.g., solid-state drive), etc.

[0307] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A method for calculating vehicle speed, characterized in that, include: Obtain the steering gear ratio function between the steering wheel and the steering wheel angle, as well as the wheel speed of each wheel; Based on the steering ratio function and the wheel speed of each wheel, the wheel speed of each wheel is converted into the equivalent speed of the vehicle at a preset position. The data quality attributes for calculating the equivalent speed of each wheel include at least one of the following: The consistency of the equivalent speeds of the two sets of paired wheels in the front-rear direction; The consistency of the equivalent speeds of the two sets of paired wheels in the left-right direction; The consistency of the equivalent speed of each wheel at both the front and rear moments; The equivalent speed of each wheel is weighted and fused based on the data quality attributes to obtain the reference speed of the car.

2. The method according to claim 1, characterized in that, The process of obtaining the steering gear ratio function between the steering wheel and the steering wheel angle includes: Read the pre-stored steering ratio function from the vehicle's memory.

3. The method according to claim 1, characterized in that, The process of obtaining the steering gear ratio function between the steering wheel and the steering wheel angle includes: The true vehicle speed is obtained by measuring the accuracy of a positioning device that is higher than that of a wheel speed meter; The steering wheel angle is determined by the steering wheel angle and the true vehicle speed; The steering ratio function is obtained by fitting the mapping data of the steering wheel angle and the steering wheel angle within a preset time period.

4. The method according to claim 1, characterized in that, The data quality attribute is calculated using the following formula: Where t represents time, μ x α represents the consistency of the equivalent speeds of two pairs of wheels in the front-rear direction. y λ represents the consistency of the equivalent speeds of the two pairs of wheels in the left-right direction. xy This represents the consistency of the equivalent speed of each wheel at the front and rear moments. fun represents a preset function. x = f(front), r(rear) indicates that x takes the value of the front wheel or the rear wheel. y = l(left), r(right) indicates that y takes the value of the left wheel or the right wheel.

5. The method according to claim 4, characterized in that, The preset functions include: Find the reciprocal of the difference between the two parameters; Alternatively, take the reciprocal of the difference of squares between the two parameters; Alternatively, find the difference in exponents of the opposites of the two parameters.

6. The method according to claim 5, characterized in that, When using the front-to-back direction, the consistency μ of the equivalent speed of the two sets of paired wheels x When performing weighted fusion calculation, the step of weighted fusion calculation of the equivalent speed of each wheel based on the data quality attributes to obtain the reference speed of the vehicle includes: Based on μ x The calculation method calculates the evaluation index μ for the front and rear wheel groups. f and μ r ; According to the following formula, μ f and μ r Normalization process is performed to obtain and Compare and The magnitude of the value determines the confidence level of the front wheel group and the rear wheel group at the current moment, and the confidence level is positively correlated with the weights in the weighted fusion calculation; The reference speed of a car can be calculated using the following formula: Among them, v output v represents the reference speed of the car. x This represents the equivalent speed of the wheel at its x-wheel speed when converted to the vehicle's preset position.

7. The method according to claim 5, characterized in that, When using the front-to-back direction, the consistency μ of the equivalent speed of the two sets of paired wheels x ; and the consistency α of the equivalent speeds of the two sets of paired wheels in the left-right direction. y When performing weighted fusion calculation, the step of weighted fusion calculation of the equivalent speed of each wheel based on the data quality attributes to obtain the reference speed of the vehicle includes: Based on μ x The calculation method calculates the evaluation index μ for the front and rear wheel groups. f and μ r ; According to the following formula, μ f and μ r Normalization process is performed to obtain and Based on α y The calculation method calculates the evaluation index α for the left and right wheel groups. l and α r ; According to the following formula, α l and α r Normalization process is performed to obtain and According to the following formula Normalization is performed: Compare x and y under different values The magnitude of the value determines the confidence level of each wheel at the current moment, and the confidence level of each wheel is positively correlated with the weight in the weighted fusion calculation. The reference speed of a car can be calculated using the following formula: Among them, v output v represents the reference speed of the car. xy This represents the equivalent speed of the wheel at its xy position when converted to the vehicle's preset position.

8. The method according to claim 5, characterized in that, When using the front-to-back direction, the consistency μ of the equivalent speed of the two sets of paired wheels x The consistency α of the equivalent speeds of the two sets of paired wheels in the left-right direction. y ; And the consistency λ of the equivalent velocity of each wheel at the front and rear moments. xy When performing weighted fusion calculation, the step of weighted fusion calculation of the equivalent speed of each wheel based on the data quality attributes to obtain the reference speed of the vehicle includes: Based on μ x The calculation method calculates the evaluation index μ for the front and rear wheel groups. f and μ r ; According to the following formula, μ f and μ r Normalization process is performed to obtain and Based on α y The calculation method calculates the evaluation index α for the left and right wheel groups. l and α r ; According to the following formula, α l and α r Normalization process is performed to obtain and Based on λ xy The calculation method calculates the evaluation index λ for each wheel at the current moment. xy,i ; λ is calculated according to the following formula. xy,i Normalization process is performed to obtain According to the following formula Normalization is performed: Compare x, y, and i under different values The magnitude of the value determines the confidence level of each wheel at the current moment, and the confidence level of each wheel is positively correlated with the weight in the weighted fusion calculation. The reference speed of a car can be calculated using the following formula: Among them, v output v represents the reference speed of the car. xy,i This represents the wheel speed xy at time i converted to the equivalent speed at the vehicle's preset position.

9. A device for calculating vehicle speed, characterized in that, include: The acquisition unit is used to acquire the steering transmission ratio function between the steering wheel and the steering wheel angle, as well as the wheel speed of each wheel; The conversion unit is used to convert the wheel speed of each wheel into the equivalent speed of the vehicle at a preset position according to the steering transmission ratio function and the wheel speed of each wheel. A calculation unit is used to calculate the data quality attributes of the equivalent speed of each wheel, wherein the data quality attributes include at least one of the following: The consistency of the equivalent speeds of the two sets of paired wheels in the front-rear direction; The consistency of the equivalent speeds of the two sets of paired wheels in the left-right direction; The consistency of the equivalent speed of each wheel at both the front and rear moments; The equivalent speed of each wheel is weighted and fused based on the data quality attributes to obtain the reference speed of the car.

10. The apparatus according to claim 9, characterized in that, The acquisition unit specifically includes: Read the pre-stored steering ratio function from the vehicle's memory.

11. The apparatus according to claim 9, characterized in that, The acquisition unit is specifically used for: The true vehicle speed is obtained by measuring the accuracy of a positioning device that is higher than that of a wheel speed meter; The steering wheel angle is determined by the steering wheel angle and the true vehicle speed; The steering ratio function is obtained by fitting the mapping data of the steering wheel angle and the steering wheel angle within a preset time period.

12. The apparatus according to claim 9, characterized in that, The data quality attribute is calculated using the following formula: Where t represents time, μ x α represents the consistency of the equivalent speeds of two pairs of wheels in the front-rear direction. y λ represents the consistency of the equivalent speeds of the two pairs of wheels in the left-right direction. xy This represents the consistency of the equivalent speed of each wheel at the front and rear moments. fun represents a preset function. x = f(front), r(rear) indicates that x takes the value of the front wheel or the rear wheel. y = l(left), r(right) indicates that y takes the value of the left wheel or the right wheel.

13. The apparatus according to claim 12, characterized in that, The preset functions include: Find the reciprocal of the difference between the two parameters; Alternatively, take the reciprocal of the difference of squares between the two parameters; Alternatively, find the difference in exponents of the opposites of the two parameters.

14. The apparatus according to claim 13, characterized in that, When using the front-to-back direction, the consistency μ of the equivalent speed of the two sets of paired wheels x When performing weighted fusion calculations, the calculation unit is specifically used for: Based on μ x The calculation method calculates the evaluation index μ for the front and rear wheel groups. f and μ r ; According to the following formula, μ f and μ r Normalization process is performed to obtain and Compare and The magnitude of the value determines the confidence level of the front wheel group and the rear wheel group at the current moment, and the confidence level is positively correlated with the weights in the weighted fusion calculation; The reference speed of a car can be calculated using the following formula: Among them, v output v represents the reference speed of the car. x This represents the equivalent speed of the wheel at its x-wheel speed when converted to the vehicle's preset position.

15. The apparatus according to claim 13, characterized in that, When using the front-to-back direction, the consistency μ of the equivalent speed of the two sets of paired wheels x ; and the consistency α of the equivalent speeds of the two sets of paired wheels in the left-right direction. y When performing weighted fusion calculations, the calculation unit is specifically used for: Based on μ x The calculation method calculates the evaluation index μ for the front and rear wheel groups. f and μ r ; According to the following formula, μ f and μ r Normalization process is performed to obtain and Based on α y The calculation method calculates the evaluation index α for the left and right wheel groups. l and α r ; According to the following formula, α l and α r Normalization process is performed to obtain and According to the following formula Normalization is performed: Compare x and y under different values The magnitude of the value determines the confidence level of each wheel at the current moment, and the confidence level of each wheel is positively correlated with the weight in the weighted fusion calculation. The reference speed of a car can be calculated using the following formula: Among them, v output v represents the reference speed of the car. xy This represents the equivalent speed of the wheel at its xy position when converted to the vehicle's preset position.

16. The apparatus according to claim 13, characterized in that, When using the front-to-back direction, the consistency μ of the equivalent speed of the two sets of paired wheels x The consistency α of the equivalent speeds of the two sets of paired wheels in the left-right direction. y ; and the consistency λ of the equivalent velocity of each wheel at both the front and rear moments. xy When performing weighted fusion calculations, the calculation unit is specifically used for: Based on μ x The calculation method calculates the evaluation index μ for the front and rear wheel groups. f and μ r ; According to the following formula, μ f and μ r Normalization process is performed to obtain and Based on α y The calculation method calculates the evaluation index α for the left and right wheel groups. l and α r ; According to the following formula, α l and α r Normalization process is performed to obtain and Based on λ xy The calculation method calculates the evaluation index λ for each wheel at the current moment. xy,i ; λ is calculated according to the following formula. xy,i Normalization process is performed to obtain According to the following formula Normalization is performed: Compare x, y, and i under different values The magnitude of the value determines the confidence level of each wheel at the current moment, and the confidence level of each wheel is positively correlated with the weight in the weighted fusion calculation. The reference speed of a car can be calculated using the following formula: Among them, v output v represents the reference speed of the car. xy,i This represents the wheel speed xy at time i converted to the equivalent speed at the vehicle's preset position.

17. The apparatus according to claim 15, characterized in that, The device is an inertial measurement unit installed on the vehicle.

18. A device for calculating vehicle speed, characterized in that, include: A processor coupled to a memory for storing programs or instructions that, when executed by the processor, cause the apparatus to perform the method as described in any one of claims 1 to 8.

19. A computer-readable storage medium, characterized in that, include: The computer-readable storage medium stores instructions that, when executed on a processor, implement the method as described in any one of claims 1-8.

20. A computer program product, the computer program product comprising instructions, characterized in that, When the instructions are executed on the processor, they implement the method as described in any one of claims 1 to 8.

21. A chip comprising one or more processing circuits, wherein, The one or more processing circuits are used to implement the method as described in any one of claims 1-8.

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