Vehicle tire radius calculation method and device and readable storage medium

Abstract

The invention provides a vehicle tire radius calculation method and device and a readable storage medium, the method is applied to the technical field of vehicles, and the method comprises the steps that driving parameters of a vehicle at the current moment are acquired; when the running parameters indicate that the vehicle runs in a steady state, determining a plurality of first preset durations by taking the current moment as the starting moment, and obtaining the running distance and the wheel rotating speed of the vehicle in each first preset duration; based on the first preset duration, integral operation is conducted on the wheel rotation speed, and the total wheel rotation number of the vehicle in each first preset duration is obtained; the tire radius of the vehicle in each first preset duration is estimated according to the driving distance and the total number of revolutions of the wheels, the multiple tire radiuses are obtained, the method can improve the accuracy of the calculated tire radiuses, and therefore the stability of vehicle driving is improved.

Description

Technical Field

[0001] The present application relates to the field of vehicle technology, and more specifically, to a method, device and readable storage medium for calculating a vehicle tire radius in the field of vehicle technology. Background Art

[0002] With the rapid development of the automobile industry, the number of cars is increasing, and traffic accidents caused by car instability are also increasing. Among them, accurate calculation of the tire radius of the vehicle plays an important role in maintaining stable driving of the vehicle. However, the accuracy of the tire radius calculation is currently low, that is, the deviation between the calculated tire radius and the actual tire radius is large, so that the vehicle control system adjusts the vehicle's operating parameters (for example, the vehicle's transmission ratio, braking force strength, etc.) according to the calculated tire radius. The accuracy is low, which reduces the stability of the vehicle's driving. Summary of the invention

[0003] The present application provides a method, device and readable storage medium for calculating the radius of a vehicle tire. The method can improve the accuracy of the calculated tire radius, thereby improving the driving stability of the vehicle.

[0004] In a first aspect, a method for calculating a tire radius of a vehicle is provided, the method comprising: obtaining driving parameters of the vehicle at a current moment; when the driving parameters indicate that the vehicle is in steady-state driving, taking the current moment as a starting moment, determining a plurality of first preset time periods, and obtaining a driving distance and a wheel speed of the vehicle in each first preset time period; based on the first preset time period, integrating the wheel speed to obtain a total number of wheel revolutions of the vehicle in each first preset time period; estimating the tire radius of the vehicle in each first preset time period based on the driving distance and the total number of wheel revolutions to obtain a plurality of tire radii; averaging the plurality of tire radii to calculate a steady-state tire radius of the vehicle.

[0005] In the above technical solution, the driving parameters of the vehicle at the current moment can be obtained, so that when the driving parameters indicate that the vehicle is in steady-state driving, the calculation of the steady-state tire radius of the vehicle is activated, that is, when the driving parameters indicate that the vehicle is in steady-state driving, the current moment is used as the starting moment, multiple first preset time lengths are determined, and the driving distance and wheel speed of the vehicle in each first preset time length are obtained. Since the tire radius of the vehicle in each first preset time length can be obtained by the driving distance of the vehicle in each first preset time length and the total number of wheel revolutions of the vehicle in each first preset time length, after obtaining the wheel speed of the vehicle in each first preset time length, the obtained wheel speed can be integrated based on the first preset time length to obtain the total number of wheel revolutions of the vehicle in each first preset time length, and then the tire radius of the vehicle in each first preset time length is estimated based on the calculated total number of wheel revolutions and driving distance to obtain multiple tire radii. After obtaining multiple tire radii, the multiple tire radii can be averaged to reduce the measurement error of the vehicle and the random error of the data, so that the steady-state tire radius of the vehicle with high accuracy and reliability can be finally obtained, thereby improving the stability of vehicle driving.

[0006] In combination with the first aspect and the above-mentioned implementation methods, in some possible implementation methods, an average of multiple tire radii is taken to calculate the steady-state tire radius of the vehicle, including: performing a sliding average of multiple tire radii according to a preset sliding window and a preset sliding step size to obtain the steady-state tire radius of the vehicle; or performing an arithmetic average of multiple tire radii to obtain the steady-state tire radius of the vehicle.

[0007] In the above technical solution, a sliding average or arithmetic average method can be used to calculate the average value of multiple tire radii to reduce the measurement error of the vehicle and the random error of the data, so that the final steady-state tire radius of the vehicle is more accurate and reliable. Among them, using a sliding average to calculate the average value of multiple tire radii can effectively reduce the abnormal tire radii existing in the multiple tire radii, thereby further improving the reliability of the calculated steady-state tire radius.

[0008] In combination with the first aspect and the above-mentioned implementation methods, in some possible implementation methods, the method also includes: obtaining the current position of the vehicle, taking the current position as the starting point, and storing a label every time the vehicle travels a preset distance; obtaining the number of labels accumulated by the vehicle in each first preset time period; and obtaining the travel distance of the vehicle in each first preset time period based on the number of labels and the preset distance.

[0009] In combination with the first aspect and the above-mentioned implementation methods, in some possible implementation methods, the current location of the vehicle is obtained by acquiring high-precision map information through an application development interface.

[0010] In the above technical solution, the current location of the vehicle can be obtained by obtaining high-precision map information through the application development interface, thereby ensuring the accurate current location of the vehicle, thereby improving the accuracy of the subsequent travel distance of the vehicle in each first preset time period based on the current location of the vehicle.

[0011] In combination with the first aspect and the above-mentioned implementations, in some possible implementations, the method further includes: when the driving parameters indicate that the vehicle is driving in a non-steady state, calculating the non-steady-state tire radius of the vehicle based on the steady-state tire radius of the vehicle.

[0012] Since the tire radius of the vehicle will change with the change of the driving state of the vehicle, that is, the tire radius of the vehicle is not fixed during the driving process of the vehicle. For example, when the driving state of the vehicle changes from steady-state driving to unsteady-state driving (for example, sudden acceleration, sudden deceleration, and sharp turns, etc.), the mass of the vehicle will be redistributed between the front, back, left, and right due to the effect of inertia, which will cause the pressure of the tire in contact with the ground to change, and then cause the tire to deform, that is, the tire radius changes. Therefore, in the above technical solution, when the driving parameters indicate that the vehicle is driving in an unsteady state, it is necessary to recalculate the tire radius of the vehicle based on the steady-state tire radius of the vehicle to obtain the tire radius of the vehicle in the case of unsteady-state driving, that is, the unsteady-state tire radius of the vehicle, thereby reducing the deviation between the calculated tire radius of the vehicle and the actual tire radius of the vehicle, and improving the accuracy of the calculated tire radius.

[0013] In combination with the first aspect and the above-mentioned implementation methods, in some possible implementation methods, the non-steady-state tire radius of the vehicle is calculated based on the steady-state tire radius of the vehicle, including: obtaining the angular velocity of the wheel and the wheel-end load of the wheel; obtaining the expansion of the wheel based on the angular velocity of the wheel, a first preset parameter and the steady-state tire radius of the vehicle, the first preset parameter being an adjustment coefficient of the tire radius; obtaining the compression of the wheel based on the wheel-end load of the wheel and the vertical stiffness of the wheel; and calculating the non-steady-state tire radius of the vehicle based on the steady-state tire radius of the vehicle, the expansion of the wheel and the compression of the wheel.

[0014] In the above technical scheme, since the deformation of the tire when the vehicle speed changes, that is, the expansion of the wheel, and the deformation of the tire when the wheel end load changes, that is, the compression of the wheel, are taken into account in the process of calculating the non-steady-state tire radius of the vehicle, the accuracy of the calculated non-steady-state tire radius of the vehicle can be improved.

[0015] In combination with the first aspect and the above-mentioned implementations, in some possible implementations, the method further includes: activating calculation of the steady-state tire radius of the vehicle when the driving parameters continue to indicate that the vehicle is driving in a steady state within a second preset time period.

[0016] In the above technical solution, when the driving parameters continue to indicate that the vehicle is in steady-state driving within the second preset time period, the calculation of the steady-state tire radius of the vehicle is reactivated. This can avoid frequent reactivation of the calculation of the steady-state tire radius due to frequent jumps in the indication results of the driving parameters (the indication results of the driving parameters change back and forth between steady-state driving and non-steady-state driving), thereby reducing the control power consumption of the vehicle.

[0017] In combination with the first aspect and the above-mentioned implementation methods, in some possible implementation methods, the driving parameters include at least one of the vehicle speed, the vehicle longitudinal acceleration, the vehicle chassis longitudinal impact force, the vehicle steering wheel steering angle, the vehicle slip rate, the vehicle lateral tilt angle and the vehicle longitudinal tilt angle, and the method also includes: when each parameter in the driving parameters is within the corresponding preset range, determining that the driving parameters indicate that the vehicle is driving in a steady state; when one parameter in the driving parameters is not within the corresponding preset range, determining that the driving parameters indicate that the vehicle is driving in a non-steady state.

[0018] In a second aspect, a device for calculating a vehicle tire radius is provided, the device comprising:

[0019] An acquisition module is used to obtain the current driving parameters of the vehicle;

[0020] A judgment module, used to judge the driving state of the vehicle according to the current driving parameters of the vehicle;

[0021] The acquisition module is further used to determine a plurality of first preset time lengths with the current time as the starting time when the driving parameters indicate that the vehicle is in steady-state driving, and to acquire the driving distance and wheel speed of the vehicle in each first preset time length;

[0022] a calculation module, configured to perform an integral operation on the wheel speed based on the first preset time length to obtain a total number of wheel revolutions of the vehicle in each first preset time length;

[0023] estimating the tire radius of the vehicle in each first preset time period according to the travel distance and the total number of wheel revolutions to obtain a plurality of tire radii;

[0024] The steady-state tire radius of the vehicle is calculated by averaging multiple tire radii.

[0025] In combination with the second aspect and the above-mentioned implementation methods, in some possible implementation methods, the calculation module is specifically used to perform a sliding average of multiple tire radii according to a preset sliding window and a preset sliding step size to obtain a steady-state tire radius of the vehicle; or, perform an arithmetic average of multiple tire radii to obtain a steady-state tire radius of the vehicle.

[0026] In combination with the second aspect and the above-mentioned implementation methods, in some possible implementation methods, the acquisition module is specifically used to obtain the current position of the vehicle, take the current position as the starting point, and store a label every time the vehicle travels a preset distance; obtain the number of labels accumulated by the vehicle in each first preset time length; and obtain the travel distance of the vehicle in each first preset time length based on the number of labels and the preset distance.

[0027] In combination with the second aspect and the above-mentioned implementation methods, in some possible implementation methods, the acquisition module obtains high-precision map information through an application development interface to obtain the current location of the vehicle.

[0028] In combination with the second aspect and the above-mentioned implementation methods, in some possible implementation methods, the calculation module is specifically used to calculate the non-steady-state tire radius of the vehicle based on the steady-state tire radius of the vehicle when the driving parameters indicate that the vehicle is driving in a non-steady state.

[0029] In combination with the second aspect and the above-mentioned implementation methods, in some possible implementation methods, the acquisition module is specifically used to obtain the angular velocity of the wheel and the wheel-end load of the wheel; the expansion of the wheel is obtained according to the angular velocity of the wheel, the first preset parameter and the steady-state tire radius of the vehicle, and the first preset parameter is the adjustment coefficient of the tire radius; the compression of the wheel is obtained according to the wheel-end load of the wheel and the vertical stiffness of the wheel; the calculation module is specifically used to calculate the non-steady-state tire radius of the vehicle based on the steady-state tire radius of the vehicle, the expansion of the wheel and the compression of the wheel.

[0030] In combination with the second aspect and the above-mentioned implementation methods, in some possible implementation methods, the device also includes an activation module for activating the calculation of the steady-state tire radius of the vehicle when the driving parameters continue to indicate that the vehicle is in steady-state driving within a second preset time period.

[0031] In combination with the second aspect and the above-mentioned implementation methods, in some possible implementation methods, the driving parameters include at least one of the vehicle speed, the vehicle longitudinal acceleration, the vehicle chassis longitudinal impact force, the vehicle steering wheel steering angle, the vehicle slip rate, the vehicle lateral tilt angle and the vehicle longitudinal tilt angle. The device also includes a determination module for determining that the driving parameters indicate that the vehicle is driving in a steady state when each parameter in the driving parameters is within a corresponding preset range; and determining that the driving parameters indicate that the vehicle is driving in a non-steady state when one parameter in the driving parameters is not within the corresponding preset range.

[0032] In a third aspect, a computer program product is provided, which includes: a computer program code, which, when executed on a computer, enables the computer to execute the method for calculating the vehicle tire radius in the first aspect or any possible implementation of the first aspect.

[0033] In a fourth aspect, a computer-readable storage medium is provided, which stores a computer program code. When the computer program code runs on a computer, the computer executes the method for calculating the vehicle tire radius in the above-mentioned first aspect or any possible implementation of the first aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a structural schematic diagram of an ECU provided in an embodiment of the present application;

[0035] Figure 2 is a schematic flow chart of a method for calculating a vehicle tire radius provided in an embodiment of the present application;

[0036] Figure 3 is a schematic flow chart of another method for calculating the radius of a vehicle tire provided in an embodiment of the present application;

[0037] Figure 4 is a schematic structural diagram of a device for calculating a vehicle tire radius provided in an embodiment of the present application;

[0038] Figure 5 It is a structural schematic diagram of a vehicle provided in an embodiment of the present application. DETAILED DESCRIPTION

[0039] The technical solution in the present application will be described clearly and in detail below in conjunction with the accompanying drawings. In the description of the embodiments of the present application, unless otherwise specified, " / " means or, for example, A / B can mean A or B: "and / or" in the text is only a description of the association relationship of associated objects, indicating that there can be three relationships, for example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, in the description of the embodiments of the present application, "multiple" means two or more than two.

[0040] In the following, the terms "first" and "second" are used for descriptive purposes only and are not to be understood as suggesting or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features.

[0041] With the rapid development of the automobile industry, the number of cars is increasing, and traffic accidents caused by car instability are also increasing. Among them, accurate calculation of the tire radius of the vehicle plays an important role in maintaining stable driving of the vehicle. However, the accuracy of the tire radius calculation is currently low, that is, the deviation between the calculated tire radius and the actual tire radius is large, so that the vehicle control system adjusts the vehicle's operating parameters (for example, the vehicle's transmission ratio, braking force strength, etc.) according to the calculated tire radius. The accuracy is low, which reduces the stability of the vehicle's driving.

[0042] Based on the above problems, the present application provides a method for calculating the radius of a vehicle tire, which can improve the accuracy of the calculated tire radius, thereby improving the driving stability of the vehicle.

[0043] It should be understood that the method of the embodiment of the present application can be applied to any electronic control unit (Electronic Control Unit, ECU) in a vehicle, and the ECU can also be any other control unit with computing function in the vehicle. For example, the ECU can be a microcontroller unit (Microcontroller Unit, MCU). The ECU can specifically include different modules, each module is used to perform different functions.

[0044] Figure 1 It is a structural diagram of an ECU provided in an embodiment of the present application.

[0045] For example, Figure 1 As shown, according to the different functions of each module, the ECU 100 may include a collection module 101, a judgment module 102 and a tire radius calculation module 103. The functions of each module are as follows:

[0046] The acquisition module 101 is responsible for acquiring the vehicle's driving parameters and rated parameters (for example, the vehicle's wheel vertical stiffness) collected by one or more sensors through a communication bus in the vehicle (for example, a Controller Area Network (CAN) bus). In addition, the acquisition module 101 can also communicate with other ECUs to achieve information sharing and coordination between various systems within the vehicle.

[0047] The driving parameter of the vehicle refers to the driving state information of the vehicle collected by the sensor. For example, when the vehicle-mounted sensor is a vehicle speed sensor, the driving parameter of the vehicle may be the vehicle speed, or when the vehicle-mounted sensor is a steering angle sensor, the driving parameter of the vehicle may be the steering angle of the vehicle's steering wheel.

[0048] Optionally, in an embodiment of the present application, the vehicle's driving parameters include one or more of the vehicle's wheel speed, wheel angular velocity, vehicle speed, steering wheel steering angle, longitudinal acceleration, lateral tilt angle, longitudinal tilt angle and chassis longitudinal impact force.

[0049] After the acquisition module 101 acquires the driving parameters of the vehicle, the driving parameters can be sent to the judgment module 102, so that the judgment module 102 judges the driving state (steady-state driving / unsteady-state driving) of the vehicle based on the driving parameters. The judgment module 102 then sends the judgment result, i.e. the driving state of the vehicle, to the tire radius calculation module 103.

[0050] After receiving the judgment result, the tire radius calculation module 103 determines whether to calculate the steady-state radius of the vehicle's tire or the unsteady-state radius of the tire according to the judgment result, that is, when the vehicle is in a steady-state driving, the steady-state radius of the vehicle's tire is calculated; when the vehicle is in an unsteady-state driving, the unsteady-state radius of the vehicle's tire is calculated.

[0051] Below through Figure 2 A method for calculating the radius of a vehicle tire provided in an embodiment of the present application is described in detail.

[0052] Figure 2 It is a schematic flow chart of a method for calculating the radius of a vehicle tire provided in an embodiment of the present application.

[0053] For example, Figure 2 As shown, taking the execution subject as ECU as an example, the method 200 includes:

[0054] Step 201, obtaining the current driving parameters of the vehicle.

[0055] In the embodiment of the present application, the driving parameters may include one or more of the vehicle's wheel speed, wheel angular velocity, vehicle speed, steering wheel steering angle, longitudinal acceleration, lateral tilt angle, longitudinal tilt angle, and chassis longitudinal impact force. For example, the driving parameters include the vehicle's speed, the vehicle's longitudinal acceleration, the vehicle's chassis longitudinal impact force, the vehicle's steering wheel steering angle, the vehicle's slip rate, the vehicle's lateral tilt angle, and the vehicle's longitudinal tilt angle, or include the vehicle's speed, the vehicle's longitudinal acceleration, the vehicle's chassis longitudinal impact force, and the vehicle's steering wheel steering angle. The embodiment of the present application does not specifically limit the number of parameters.

[0056] Among them, the vehicle speed can be obtained through devices such as a vehicle speed sensor or a wheel speed sensor, the angular velocity of the wheel can be obtained through devices such as a wheel speed sensor, the longitudinal acceleration of the vehicle can be obtained through devices such as an inertial measurement unit or an accelerometer (Accelerometer), the longitudinal impact force of the vehicle's chassis can be obtained through devices such as an inertial measurement unit, a strain gauge sensor or a piezoelectric sensor, the steering wheel steering angle of the vehicle can be obtained through devices such as a steering angle sensor or a photoelectric encoder, the lateral tilt angle of the vehicle and the longitudinal tilt angle of the vehicle can be obtained through devices such as an inertial measurement unit gyroscope or an accelerometer, and the embodiments of the present application make specific restrictions on this.

[0057] After obtaining the vehicle speed and the angular velocity of the wheels, the vehicle slip rate can be obtained based on the vehicle speed and the angular velocity of the wheels. It should be understood that the vehicle slip rate is an important parameter when the vehicle tire is in contact with the ground. It is used to describe the difference between the actual speed and the theoretical speed of the vehicle tire relative to the ground during rolling. The slip rate has a significant impact on the vehicle's traction, braking performance and handling stability. The vehicle slip rate is generally divided into two cases: (1) Driving wheel slip rate: When the driving wheel provides driving force, if the linear speed of the tire is less than the speed of the vehicle, slip will occur. In this case, the slip rate is positive. (2) Driven wheel slip rate: When the vehicle brakes, if the linear speed of the tire is greater than the speed of the vehicle, slip will occur. In this case, the slip rate is negative.

[0058] Specifically, the slip rate of the vehicle can be obtained by the following formula (1):

[0059]

[0060] Wherein, S is the slip rate of the vehicle, v is the speed of the vehicle, ω is the angular velocity of the wheel, and r is the tire radius stored in the vehicle's internal memory.

[0061] Step 202, judging the driving state of the vehicle according to the current driving parameters of the vehicle.

[0062] In the embodiment of the present application, the driving state of the vehicle can be divided into steady-state driving and unstable driving. Among them, steady-state driving can be understood as the situation that the vehicle does not have sharp turns, sharp acceleration, sharp deceleration, wheel slippage, steep slopes, and steep slopes during driving, which will cause the tire radius to change significantly; correspondingly, unstable driving can be understood as the situation that the vehicle does not have sharp turns, sharp acceleration, sharp deceleration, wheel slippage, steep slopes, and steep slopes during driving, which will cause the tire radius to change significantly.

[0063] It should be noted that in order to enable the judgment module of the ECU to accurately and quickly determine the driving state of the vehicle based on the current driving parameters of the vehicle, the developers can set a variation range, i.e., a preset range, for each parameter in the driving parameters in advance based on experimental data and experience, so that the judgment module of the ECU can directly determine the driving state of the vehicle according to the preset range corresponding to each parameter after obtaining the driving parameters of the vehicle.

[0064] Specifically, when each of the driving parameters is within the corresponding preset range, it is determined that the driving parameters indicate that the vehicle is driving in a steady state; when one of the driving parameters is not within the corresponding preset range, it is determined that the driving parameters indicate that the vehicle is driving in an unsteady state.

[0065] For example, the driving parameters include the vehicle speed and the vehicle steering wheel steering angle. The preset range corresponding to the vehicle speed is (3km / h~50km / h), and the preset range corresponding to the vehicle steering wheel steering angle is (-45°~+45°). When the acquired vehicle speed is 45km / h and the vehicle steering wheel steering angle is 10°, the ECU judgment module can determine that the vehicle speed (45km / h) is within the corresponding preset range (3km / h~50km / h), and the vehicle steering wheel steering angle is also within the corresponding preset range (-45°~+45°), that is, the ECU judgment module can determine that the vehicle is driving in a steady state.

[0066] For another example, the driving parameters include the vehicle speed and the vehicle steering wheel steering angle. The preset range corresponding to the vehicle speed is (3km / h to 50km / h), and the preset range corresponding to the vehicle steering wheel steering angle is (-45° to +45°). When the acquired vehicle speed is 60km / h and the vehicle steering wheel steering angle is 10°, the ECU judgment module can determine that the vehicle speed (45km / h) is not within the corresponding preset range (3km / h to 50km / h), and the vehicle steering wheel steering angle is within the corresponding preset range (-45° to +45°), that is, the ECU judgment module can determine that the vehicle is driving in an unsteady state.

[0067] The following specifically describes methods for calculating the tire radius of a vehicle for steady-state driving and non-steady-state driving. When the vehicle is in steady-state driving, the steady-state tire radius of the vehicle can be calculated according to the process of steps 203A to 206A or steps 204B to 206B.

[0068] Step 203A, when the driving parameters indicate that the vehicle is in steady-state driving, taking the current moment as the starting moment, determining a plurality of first preset time lengths, and obtaining the driving distance and wheel speed of the vehicle in each first preset time length.

[0069] It should be noted that in order to avoid frequent reactivation of the calculation of the steady-state tire radius due to frequent jumps in the indication results of the driving parameters (that is, the indication results of the driving parameters change back and forth between the vehicle being steady-state driving and the vehicle being non-steady-state driving), in a possible implementation manner, the calculation of the steady-state tire radius of the vehicle can be reactivated when the driving parameters continue to indicate that the vehicle is steady-state driving within a second preset time period, that is, the subsequent implementation steps with the current moment as the starting moment and multiple first preset time periods are determined to be started again, thereby effectively avoiding frequent reactivation of the calculation of the steady-state tire radius due to frequent jumps in the indication results of the driving parameters, and reducing unnecessary control power consumption of the vehicle.

[0070] The first preset time length and the number of the first preset time lengths may be set in advance by the developer based on experimental data and experience. For example, the developer sets the first preset time length to 10 seconds and the number of the first preset time lengths to 3.

[0071] In a possible implementation, when the tire radius calculation module of the ECU receives a signal from the judgment module that the vehicle is driving in a steady state, the tire radius calculation module of the ECU will take the current moment as the starting moment, determine multiple first preset time lengths, and obtain the driving distance and wheel speed of the vehicle in each first preset time length.

[0072] For example, when the first preset time is 10 seconds, the number of the first preset time is 3, and the time when the vehicle is in steady-state driving is determined to be 12:00:00, the tire radius calculation module of the ECU will use 12:00:0 as the starting time, and sequentially determine three 10 seconds, that is, the three 10 seconds correspond to 12:00:10, 12:00:20 and 12:00:30, and obtain the driving distance and wheel speed of the vehicle in each 10 seconds. The wheel speed can be obtained by a wheel speed sensor (e.g., a magnetoelectric sensor, a photoelectric sensor, a Hall effect sensor).

[0073] Next, a detailed description is given in three steps, in which the tire radius calculation module of the ECU obtains a specific implementation method for the vehicle's driving distance in each first preset time period.

[0074] Step (1), obtaining the current location of the vehicle, taking the current location as the starting point, and storing a tag every time the vehicle travels a preset distance.

[0075] In a possible implementation, the current location of the vehicle may be obtained by acquiring Enhanced High Precision Map (EHP) information through an Application Programming Interface (API).

[0076] Among them, the API interface is an interface that allows interaction and communication between different software systems (for example, the vehicle system and the server system).

[0077] EHP is a detailed map designed specifically for autonomous driving and advanced driver assistance systems (ADAS). It can provide more accurate vehicle location information and rich road environment information than traditional navigation maps.

[0078] From the above, it can be seen that since EHP can provide accurate vehicle position information, this method can enable the tire radius calculation module of the ECU to obtain the accurate current position of the vehicle, thereby improving the accuracy of the subsequent travel distance of the vehicle in each first preset time period based on the current position of the vehicle.

[0079] It should be noted that in the relevant communication protocols of high-precision maps (for example, HERE HD Live Map protocol, TomTom HD Map protocol, etc.), it is believed that 128m can meet most application requirements of vehicles. Therefore, in order to reduce data transmission between vehicles, 128m is usually defined as the unit distance traveled by the vehicle. In the embodiment of the present application, in order to keep synchronized with the communication protocol of the high-precision map, the preset distance is 128m defined for the communication protocol of the high-precision map.

[0080] In an embodiment of the present application, the stored label can be represented by Offset, that is, every time the vehicle travels a preset distance, a label is stored, and the current position of the vehicle is recorded as Offset0. Every time the vehicle travels a preset distance, the tire radius calculation module of the ECU will update the Offset once, thereby obtaining Offset1, Offset2, Offset3... in sequence, and each updated Offset is stored.

[0081] In one possible implementation, after the tire radius calculation module of the ECU obtains the current position of the vehicle through the API interface, it can use the current position as a starting point to obtain high-precision map information through the API interface to determine whether the vehicle has traveled a preset distance, so as to store a label every time the vehicle travels a preset distance.

[0082] For example, when the current position of the vehicle is (X, Y) and the preset distance is 128m, the tire radius calculation module of the ECU will take (X, Y) as the starting point and obtain high-precision map information through the API interface to determine whether the vehicle has traveled 128m. Therefore, every time the vehicle travels 128m, a label is stored, that is, the Offset is updated once, and each updated Offset is stored.

[0083] Step (2), obtaining the number of tags accumulated and stored by the vehicle in each first preset time period.

[0084] It can be seen from the above embodiment that the tire radius calculation module of the ECU will store a label every time the vehicle travels a preset distance. Therefore, in order to obtain the vehicle's travel distance in each first preset time period in the future, in this embodiment, the tire radius calculation module of the ECU needs to obtain the number of labels accumulated and stored by the vehicle in each first preset time period, that is, the number of updated Offsets, so as to directly determine the vehicle's travel distance in each first preset time period based on the number of labels and the fixed preset distance in the future.

[0085] Exemplarily, when the first preset time length is 10 seconds and the number of first preset time lengths is 3, the vehicle updates the Offset once in the first 10 seconds to obtain Offset1; updates the Offset twice in the second 10 seconds to obtain Offset2 and Offset3; and updates the Offset once in the third 10 seconds to obtain Offset4, the tire radius calculation module of the ECU will determine that the cumulative number of tags stored in the first 10 seconds is 1, the cumulative number of tags stored in the second 10 seconds is 2, and the cumulative number of tags stored in the third 10 seconds is 1.

[0086] Step (3), according to the number of tags and the preset distance, obtain the driving distance of the vehicle in each first preset time period.

[0087] Exemplarily, when the first preset time length is 10 seconds and the number of first preset time lengths is 3, the tire radius calculation module of the ECU determines that the cumulative number of tags stored in the first 10 seconds is 1, the cumulative number of tags stored in the second 10 seconds is 2, and the cumulative number of tags stored in the third 10 seconds is 1, the tire radius calculation module of the ECU will obtain that the vehicle's driving distance in the first 10 seconds is 128m×1=128m, the tire radius calculation module of the ECU will obtain that the vehicle's driving distance in the second 10 seconds is 128m×2=256m, and the tire radius calculation module of the ECU will obtain that the vehicle's driving distance in the third 10 seconds is 128m×1=128m.

[0088] It should be noted that, in this embodiment, since the tire radius calculation module of the ECU will only store a label each time the vehicle travels 128m (preset distance), it is possible that the vehicle actually travels 158m in the first preset time period, but the tire radius calculation module of the ECU obtains the situation that the vehicle's travel distance in the first preset time period is 128m based on the accumulated number of labels and the preset distance. That is, there is an error between the calculated travel distance of the vehicle in the first preset time period and the actual travel distance of the vehicle. In order to avoid this error, the embodiment of the present application also provides another specific method of calculating the tire radius of the vehicle, which can be specifically referred to steps 204B to 206B in the following embodiment.

[0089] Step 204A: Based on the first preset time length, perform an integral operation on the wheel speed to obtain the total number of wheel revolutions of the vehicle in each first preset time length.

[0090] It should be noted that since the tire radius of the vehicle in each first preset time length can be obtained by the driving distance of the vehicle in each first preset time length and the total number of wheel revolutions of the vehicle in each first preset time length, after obtaining the wheel speed of the vehicle in each first preset time length, the tire radius calculation module of the ECU can integrate the obtained wheel speed based on the first preset time length, so as to obtain the total number of wheel revolutions of the vehicle in each first preset time length, so that the tire radius of the vehicle in each first preset time length can be estimated according to the calculated total number of wheel revolutions and driving distance, so as to obtain multiple tire radii.

[0091] It should be understood that the wheel speed sensor usually updates the wheel speed of the vehicle once every certain time interval (for example, 1 second). In this embodiment, the wheel speed is integrated to obtain the total number of wheel revolutions of the vehicle in each first preset time length. It can be understood that the wheel speed is discretely integrated to obtain the total number of wheel revolutions of the vehicle in each first preset time length, that is, all the wheel speeds updated by the wheel speed sensor in the first preset time length are accumulated.

[0092] Specifically, the tire radius calculation module of the ECU can calculate the total number of wheel revolutions of the vehicle in each first preset time length by the following formula (2):

[0093]

[0094] Wherein, N is the total number of wheel revolutions of the vehicle in the first preset time period, n is the wheel speed of the vehicle updated every 1 second by the wheel speed sensor, and x is the number of times the wheel speed sensor updates the wheel speed in the first preset time period.

[0095] It should be noted that the wheel speed sensor usually updates the wheel speed in units of rpm, i.e., revolutions per minute. Therefore, when all the wheel speeds updated by the wheel speed sensor in the first preset time period are added up, the wheel speed needs to be converted from revolutions per minute (rpm) to radians per second (rps), which corresponds to n / 60 in Formula 2.

[0096] Step 205A, estimating the tire radius of the vehicle in each first preset time period according to the driving distance and the total number of wheel revolutions, to obtain multiple tire radii.

[0097] Specifically, the tire radius calculation module of the ECU can estimate the tire radius of the vehicle in each first preset time period by the following formula (3):

[0098]

[0099] Wherein, R is the tire radius of the vehicle in the first preset time, S is the driving distance of the vehicle in the first preset time, and N is the total number of wheel revolutions.

[0100] Step 206A, averaging multiple tire radii to calculate the steady-state tire radius of the vehicle.

[0101] It should be noted that in order to reduce the measurement error of the vehicle and the random error of the data, in the embodiment of the present application, after the tire radius calculation module of the ECU obtains multiple tire radii, it is necessary to find the average of the multiple tire radii to obtain a steady-state tire radius of the vehicle with higher accuracy and reliability.

[0102] In a possible implementation, the tire radius calculation module of the ECU may use a sliding average or an arithmetic average to average multiple tire radii, which is not limited in this embodiment of the present application.

[0103] The following describes the specific implementation methods of the tire radius calculation module of the ECU using sliding average and arithmetic average to average multiple tire radii:

[0104] First, when the tire radius calculation module of the ECU adopts sliding average to calculate the average value of multiple tire radii, the multiple tire radii can be sliding averaged according to a preset sliding window and a preset sliding step to obtain the steady-state tire radius of the vehicle.

[0105] The sliding window refers to the number of data points considered when calculating the average value, that is, the number of tire radii. For example, when the sliding window size is 2, the first two data points will be taken to calculate the average value when calculating the first average value. When calculating the second average value, it will move according to the sliding step size. After moving, the two nearest data points will be taken in turn to calculate the average value. The calculation of the third average value, the fourth average value, etc. is the same as the calculation of the second average value, which will not be repeated here.

[0106] Sliding step size: refers to the step size of each moving window. For example, when the sliding step size is 1, the window will move back one data point after each average calculation. When the sliding step size is 2, the window will move back two data points after each average calculation.

[0107] For example, when the sliding window is 2, the sliding step is 1, and the multiple tire radii obtained by the tire radius calculation module of the ECU are 250mm, 240mm, 245mm and 251mm respectively, the tire radius calculation module takes the first two tire radii of 250mm and 240mm according to the sliding window (2), calculates the average value for the first time, and obtains (250mm+240mm) / 2=245; the sliding step is 1, and after calculating the average value for the first time, slides to the next window, that is, moves back one tire radius, and takes the nearest tire radius in turn. 240mm and 245mm, the average value is calculated for the second time, and (240mm+245mm) / 2=242.5 is obtained; after the second average value is calculated, a window is slid again to take the tire radius 245mm and 251mm, and the average value is calculated for the third time to obtain (245mm+254mm) / 2=248, and finally the average value of 245, 242.5 and 248 is calculated to obtain the final steady-state tire radius of the vehicle, that is, the final steady-state tire radius of the vehicle is (245mm+242.5mm+248mm) / 3≈245.2.

[0108] The second method is to perform arithmetic averaging on multiple tire radii to obtain the steady-state tire radius of the vehicle.

[0109] Exemplarily, when the tire radius calculation module of the ECU obtains multiple tire radii of 250mm, 240mm, 245mm and 251mm respectively, the arithmetic mean of 250mm, 240mm, 245mm and 251mm is calculated to obtain the steady-state tire radius of the vehicle, that is, the steady-state tire radius of the vehicle is (250mm+240mm+245mm+251mm) / 4=246.5.

[0110] In this embodiment, after obtaining multiple tire radii, the multiple tire radii are averaged, thereby reducing the measurement error of the vehicle and the random error of the data, so that the final steady-state tire radius of the vehicle has higher accuracy and reliability.

[0111] After introducing the specific implementation method of calculating the steady-state tire radius of the vehicle when the first type of vehicle is in steady-state driving, the following will introduce the implementation method of calculating the steady-state tire radius of the vehicle when the second type of vehicle is in steady-state driving. For details, please refer to the following steps 203B to 206B.

[0112] Step 203B: When the driving parameters indicate that the vehicle is driving in a steady state, obtain the current position of the vehicle, determine multiple preset distances with the current position as the starting point, and obtain the driving time and wheel speed of the vehicle in each preset distance.

[0113] The preset distance is 128m. For the description of the preset distance, please refer to the above embodiment, which will not be repeated here. The number of the preset distances can be set by the developer in advance based on experimental data and experience. For example, the developer sets the number of preset distances to 3.

[0114] In a possible implementation, when the tire radius calculation module of the ECU receives the information sent by the judgment module that the vehicle is in steady-state driving, the tire radius calculation module of the ECU will obtain the current position of the vehicle, determine multiple preset distances with the current position as the starting point, and obtain the driving time and wheel speed of the vehicle in each preset distance. The wheel speed can be obtained by a wheel speed sensor (e.g., a magnetoelectric sensor, a photoelectric sensor, a Hall effect sensor).

[0115] It should be understood that the tire radius calculation module of the ECU obtains the current position of the vehicle in the same manner as in the above embodiment, that is, the current position of the vehicle is obtained through the API interface.

[0116] In one possible implementation, after the tire radius calculation module of the ECU obtains the current position of the vehicle through the API interface, it can take the current position as the starting point and obtain high-precision map information through the API interface to determine whether the vehicle has traveled a preset distance. Then, every time the vehicle travels a preset distance, the current time is obtained once through the on-board network to obtain the driving time of the vehicle in each preset distance.

[0117] For example, when the time when the vehicle is in steady-state driving is 12:00:00, the number of distances is 3, and the current position of the vehicle in steady-state driving is (X, Y), the tire radius calculation module of the ECU will use (X, Y) as the starting point to determine three preset distances in sequence, that is, three 128 meters. When it is determined that the vehicle has traveled the first 128 meters, the current time is obtained through the vehicle network, for example, the current time obtained is 12:00:10; when it is determined that the vehicle has traveled the second 128 meters, the tire radius calculation module of the ECU will calculate the distances again. The current time is obtained through the vehicle network, for example, the current time obtained is 12:00:18; when it is determined that the vehicle has traveled the third 128 meters, the current time will continue to be obtained through the vehicle network, for example, the current time obtained is 12:00:28, and then, the driving time of the vehicle in the first 128 meters is 10 seconds, the driving time of the vehicle in the second 128 meters is 8 seconds, and the driving time of the vehicle in the third 128 meters is 10 seconds, thereby obtaining the driving time of the vehicle in each 128 meters.

[0118] Step 204B: Based on the driving time, perform an integral operation on the wheel speed to obtain the total number of wheel revolutions of the vehicle in each preset distance.

[0119] Step 205B: Estimate the tire radius of the vehicle at each preset distance according to the driving distance and the total number of wheel revolutions to obtain multiple tire radii.

[0120] Step 206B: average multiple tire radii to calculate the steady-state tire radius of the vehicle.

[0121] The implementation of the above steps 204B to 206B can be found in the above embodiments and will not be described in detail here.

[0122] It should be noted that in this embodiment, since the multiple tire radii are obtained based on multiple fixed preset distances, the situation in the above embodiment where there is an error between the calculated driving distance of the vehicle in the first preset time period and the actual driving distance of the vehicle can be avoided.

[0123] After introducing two methods for calculating the steady-state tire radius of a vehicle in the case of steady-state driving, the following introduces a method for calculating the unsteady-state tire radius of a vehicle in the case of unsteady-state driving. In the case of unsteady-state driving, the unsteady-state tire radius of the vehicle can be calculated according to the process of steps 301 to 303.

[0124] Figure 3 It is a schematic flow chart of another method for calculating the radius of a vehicle tire provided in an embodiment of the present application.

[0125] For example, Figure 3 As shown, taking the execution subject as ECU as an example, the method 300 includes:

[0126] Step 301: Obtain the current driving parameters of the vehicle.

[0127] Step 302: Determine the driving state of the vehicle according to the current driving parameters of the vehicle.

[0128] The specific implementation of step 301 can be found in the above embodiment and will not be described again here.

[0129] Step 303: When the driving parameters indicate that the vehicle is driving in an unsteady state, the unsteady tire radius of the vehicle is calculated according to the steady tire radius of the vehicle.

[0130] It should be noted that the tire radius of the vehicle will change as the vehicle's driving state changes, that is, the tire radius of the vehicle is not fixed during the driving process of the vehicle. For example, when the vehicle's driving state changes from steady-state driving to non-steady-state driving, the mass of the vehicle will be redistributed between the front, back, left and right due to the effect of inertia, which will cause the pressure of the tire contacting the ground to change, and then cause the tire to deform, that is, the tire radius will change. Therefore, in the embodiment of the present application, when the driving parameters indicate that the vehicle is in non-steady-state driving, it is necessary to recalculate the non-steady-state tire radius of the vehicle.

[0131] Among them, for the relevant description of determining that the vehicle is in non-steady-state driving, please refer to the above embodiment, which will not be repeated here.

[0132] In one possible implementation, when the tire radius calculation module of the ECU receives a signal from the judgment module that the vehicle is traveling in a non-steady state, the tire radius calculation module of the ECU will recalculate the tire radius of the vehicle based on the steady-state tire radius of the vehicle to obtain the tire radius of the vehicle when it is traveling in a non-steady state, that is, the non-steady-state tire radius of the vehicle, thereby reducing the deviation between the calculated tire radius of the vehicle and the actual tire radius of the vehicle and improving the accuracy of the calculated tire radius.

[0133] The following is a detailed introduction in four steps, which shows the specific implementation method of the tire radius calculation module of EUC for calculating the non-steady-state tire radius of the vehicle based on the steady-state tire radius of the vehicle.

[0134] Step (1), obtaining the angular velocity of the wheel and the wheel end load of the wheel.

[0135] Among them, the angular velocity of the wheel can be obtained by devices such as a wheel speed sensor or an angular velocity sensor, and the wheel end load of the wheel can be obtained by devices such as a strain gauge sensor or a piezoelectric sensor, which are specifically limited in the embodiments of the present application.

[0136] It should be understood that wheel end load refers to the vertical force that the vehicle tire is subjected to when it touches the ground, that is, the load on the contact point between the tire and the ground. The wheel end load will affect the radius, wear and driving status of the tire.

[0137] Step (2), obtaining the expansion amount of the wheel according to the angular velocity of the wheel, a first preset parameter and the steady-state tire radius of the vehicle, wherein the first preset parameter is an adjustment coefficient of the tire radius.

[0138] It should be noted that when a vehicle accelerates sharply, the friction between the tire and the ground will increase, which will cause the tire temperature to rise. However, as the tire temperature rises, the air pressure in the tire will also increase, because the gas will expand when heated, and the tire material itself will also expand slightly due to the temperature rise. Therefore, under the combined effect of these two factors, the radius of the vehicle's tire will increase slightly.

[0139] Therefore, in order to reduce the deviation between the calculated non-steady-state tire radius of the vehicle and the actual tire radius of the vehicle, in this embodiment, when the tire radius calculation module of the ECU determines that the vehicle is driving in a non-steady-state, it will first calculate the expansion of the wheel based on the angular velocity of the wheel, the adjustment coefficient of the tire radius (first preset parameter) and the steady-state tire radius of the vehicle, so that the expansion of the wheel can be taken into account when calculating the non-steady-state tire radius of the vehicle, thereby improving the accuracy of the calculated non-steady-state tire radius of the vehicle.

[0140] It should be understood that the tire radius adjustment coefficient is a parameter used to correct or adjust the tire radius estimation value. Especially when the vehicle is in a non-steady-state driving state, this coefficient can help improve the accuracy of the tire radius estimation, thereby improving the stability of the vehicle.

[0141] Specifically, the tire radius calculation module of the ECU can calculate the expansion of the wheel using the following formula (4):

[0142] A=C×R1×u 2 (Formula 4)

[0143] Among them, A is the expansion of the wheel, C is the adjustment coefficient of the tire radius, R1 is the steady-state tire radius of the vehicle, and u is the angular velocity of the wheel.

[0144] Step (3), obtaining the compression of the wheel according to the wheel end load and the vertical stiffness of the wheel.

[0145] It should be noted that when the vehicle accelerates, decelerates or turns sharply, the driving force will cause the tire to generate a large longitudinal force, which will increase the pressure in the contact area between the tire and the ground, and then cause the tire to deform, that is, the tire radius will be slightly reduced.

[0146] Similarly, in order to reduce the deviation between the calculated non-steady-state tire radius of the vehicle and the actual tire radius of the vehicle, in this embodiment, when the tire radius calculation module of the ECU determines that the vehicle is traveling in an unsteady state, the compression of the wheel will be calculated based on the wheel end load and the vertical stiffness of the wheel, so that the compression of the wheel can be taken into account when calculating the non-steady-state tire radius of the vehicle, so as to further improve the accuracy of the calculated non-steady-state tire radius of the vehicle.

[0147] It should be understood that the vertical stiffness of a wheel refers to the ability of the tire to resist deformation in the vertical direction. It describes the relationship between the amount of deformation of the tire and the vertical load when it is subjected to a vertical load (such as the weight of the vehicle). Vertical stiffness is an important parameter of tire performance and has a significant impact on the comfort, handling and stability of the vehicle.

[0148] Specifically, the tire radius calculation module of the ECU can calculate the compression of the wheel using the following formula (5):

[0149]

[0150] Among them, B is the compression of the wheel, F is the wheel end load, and K is the vertical stiffness of the wheel.

[0151] Step (4), based on the steady-state tire radius of the vehicle, the expansion amount of the wheel and the compression amount of the wheel, calculate the non-steady-state tire radius of the vehicle.

[0152] Specifically, the tire radius calculation module of the ECU can calculate the non-steady-state tire radius of the vehicle by the following formula (6):

[0153] R2=R1+AB (Formula 6)

[0154] Among them, R2 is the compression of the wheel, A is the expansion of the wheel, and B is the compression of the wheel.

[0155] In this embodiment, the deformation of the tire when the vehicle speed changes, that is, the expansion of the wheel, and the deformation of the tire when the wheel end load changes, that is, the compression of the wheel are taken into account in the process of calculating the non-steady-state tire radius of the vehicle. Therefore, the accuracy of the calculated non-steady-state tire radius of the vehicle can be improved.

[0156] Figure 4 It is a structural schematic diagram of a vehicle tire radius calculation device provided in an embodiment of the present application.

[0157] For example, Figure 4 As shown, the device 400 includes:

[0158] The acquisition module 401 is used to acquire the current driving parameters of the vehicle;

[0159] The judgment module 402 is used to judge the driving state of the vehicle according to the driving parameters of the vehicle at the current moment;

[0160] The acquisition module 401 is further configured to determine a plurality of first preset time periods with the current time being the starting time when the driving parameters indicate that the vehicle is in steady-state driving, and to acquire the driving distance and wheel speed of the vehicle in each first preset time period;

[0161] A calculation module 403 is used to perform an integral operation on the wheel speed based on the first preset time length to obtain a total number of wheel revolutions of the vehicle in each first preset time length;

[0162] estimating the tire radius of the vehicle in each first preset time period according to the travel distance and the total number of wheel revolutions to obtain a plurality of tire radii;

[0163] The steady-state tire radius of the vehicle is calculated by averaging multiple tire radii.

[0164] It should be noted that the acquisition module 401 corresponds to Figure 1 The acquisition module 101 in the determination module 402 corresponds to Figure 1 The judgment module 102 in the calculation module 403 corresponds to Figure 1 The tire radius calculation module 103 in FIG.

[0165] In one possible implementation, the calculation module 403 is specifically used to perform a sliding average on multiple tire radii according to a preset sliding window and a preset sliding step size to obtain a steady-state tire radius of the vehicle; or, perform an arithmetic average on multiple tire radii to obtain a steady-state tire radius of the vehicle.

[0166] In one possible implementation, the acquisition module 402 is specifically used to obtain the current position of the vehicle, taking the current position as the starting point, and storing a label every time the vehicle travels a preset distance; obtaining the number of labels accumulated by the vehicle in each first preset time period; and obtaining the travel distance of the vehicle in each first preset time period based on the number of labels and the preset distance.

[0167] In a possible implementation, the acquisition module 402 obtains high-precision map information through an application development interface to obtain the current location of the vehicle.

[0168] In a possible implementation, the device further includes a calculation module 403, which is specifically used to calculate the non-steady-state tire radius of the vehicle based on the steady-state tire radius of the vehicle when the driving parameters indicate that the vehicle is driving in a non-steady state.

[0169] In a possible implementation, the acquisition module 402 is specifically used to obtain the angular velocity of the wheel and the wheel-end load of the wheel; the expansion of the wheel is obtained according to the angular velocity of the wheel, a first preset parameter and the steady-state tire radius of the vehicle, and the first preset parameter is the adjustment coefficient of the tire radius; the compression of the wheel is obtained according to the wheel-end load of the wheel and the vertical stiffness of the wheel; the calculation module 403 is specifically used to calculate the non-steady-state tire radius of the vehicle based on the steady-state tire radius of the vehicle, the expansion of the wheel and the compression of the wheel.

[0170] In a possible implementation, the device further includes an activation module, which is used to activate the calculation of the steady-state tire radius of the vehicle when the driving parameters continue to indicate that the vehicle is driving in a steady state within a second preset time period.

[0171] In a possible implementation, the driving parameters include at least one of the vehicle speed, the vehicle longitudinal acceleration, the vehicle chassis longitudinal impact force, the vehicle steering wheel steering angle, the vehicle slip rate, the vehicle lateral tilt angle and the vehicle longitudinal tilt angle. The device also includes a determination module for determining that the driving parameters indicate that the vehicle is driving in a steady state when each parameter in the driving parameters is within a corresponding preset range; and determining that the driving parameters indicate that the vehicle is driving in a non-steady state when one parameter in the driving parameters is not within the corresponding preset range.

[0172] Figure 5 It is a structural schematic diagram of a vehicle provided in an embodiment of the present application.

[0173] For example, Figure 5As shown, the vehicle 500 includes: a memory 501 and a processor 502, wherein the memory 501 stores an executable program code 503, and the processor 502 is used to call and execute the executable program code 503 to perform a method for calculating the radius of a vehicle tire.

[0174] In addition, an embodiment of the present application also protects a device, which may include a memory and a processor, wherein the memory stores an executable program code, and the processor is used to call and execute the executable program code to execute a method for calculating the radius of a vehicle tire provided in an embodiment of the present application.

[0175] In this embodiment, the functional modules of the device can be divided according to the above method example. For example, each functional module can be corresponded, or two or more functions can be integrated into one processing module. The above integrated module can be implemented in the form of hardware. It should be noted that the division of modules in this embodiment is schematic and is only a logical function division. There may be other division methods in actual implementation.

[0176] In the case of dividing each functional module according to each function, the device may further include an activation module and a determination module, etc. It should be noted that all relevant contents of each step involved in the above method embodiment can be referred to the functional description of the corresponding functional module, which will not be repeated here.

[0177] It should be understood that the device provided in this embodiment is used to execute the above-mentioned method for calculating the radius of a vehicle tire, and thus can achieve the same effect as the above-mentioned implementation method.

[0178] In the case of an integrated unit, the device may include a processing module and a storage module. When the device is applied to a vehicle, the processing module may be used to control and manage the actions of the vehicle. The storage module may be used to support the vehicle in executing related program codes, etc.

[0179] The processing module may be a processor or a controller, which may implement or execute various exemplary logic blocks, modules and circuits shown in conjunction with the disclosure of the present application. The processor may also be a combination that implements computing functions, such as a combination of one or more microprocessors, a combination of digital signal processing (DSP) and a microprocessor, etc. The storage module may be a memory.

[0180] In addition, the device provided in the embodiments of the present application may specifically be a chip, a component or a module, and the chip may include a connected processor and a memory; wherein the memory is used to store instructions, and when the processor calls and executes the instructions, the chip can execute a method for calculating the radius of a vehicle tire provided in the above embodiments.

[0181] This embodiment also provides a computer-readable storage medium, in which a computer program code is stored. When the computer program code is executed on a computer, the computer executes the above-mentioned related method steps to implement a method for calculating the radius of a vehicle tire provided in the above embodiment.

[0182] This embodiment also provides a computer program product. When the computer program product is run on a computer, the computer is caused to execute the above-mentioned related steps to implement a method for calculating the radius of a vehicle tire provided in the above embodiment.

[0183] Among them, the device, computer-readable storage medium, computer program product or chip provided in this embodiment is used to execute the corresponding method provided above. Therefore, the beneficial effects that can be achieved can refer to the beneficial effects in the corresponding method provided above, and will not be repeated here.

[0184] Through the description of the above implementation methods, technical personnel in the relevant field can understand that for the convenience and simplicity of description, only the division of the above-mentioned functional modules is used as an example. In actual applications, the above-mentioned functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above.

[0185] In the embodiments provided in the present application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic, for example, the division of modules or units is only a logical function division, and there may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another device, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0186] The above contents are only specific implementation methods of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A method for calculating the radius of a vehicle tire, characterized in that: The method comprises: Get the vehicle's current driving parameters; When the driving parameter indicates that the vehicle is in steady-state driving, taking the current moment as the starting moment, determining a plurality of first preset time periods, and obtaining the driving distance and wheel speed of the vehicle in each first preset time period; Based on the first preset time length, performing an integral operation on the wheel speed to obtain a total number of wheel revolutions of the vehicle in each first preset time length; estimating the tire radius of the vehicle in each first preset time period according to the driving distance and the total number of wheel revolutions to obtain a plurality of tire radii; The plurality of tire radii are averaged to calculate a steady-state tire radius of the vehicle.

2. The method according to claim 1, characterized in that The averaging of the plurality of tire radii to calculate the steady-state tire radius of the vehicle includes: According to a preset sliding window and a preset sliding step length, performing sliding averaging on the multiple tire radii to obtain a steady-state tire radius of the vehicle; Alternatively, the plurality of tire radii are arithmetic averaged to obtain the steady-state tire radius of the vehicle.

3. The method according to claim 1 or 2, characterized in that: The method further comprises: Obtaining the current location of the vehicle, taking the current location as a starting point, storing a label each time the vehicle travels a preset distance; Obtaining the number of tags accumulated and stored by the vehicle in each first preset time period; The driving distance of the vehicle in each first preset time period is obtained according to the number of tags and the preset distance.

4. The method according to claim 3, characterized in that The current location of the vehicle is obtained by acquiring high-precision map information through an application development interface.

5. The method according to claim 1 or 2, characterized in that: The method further comprises: When the driving parameter indicates that the vehicle is driving in a non-steady state, the non-steady state tire radius of the vehicle is calculated according to the steady state tire radius of the vehicle.

6. The method according to claim 5, characterized in that The calculating the non-steady-state tire radius of the vehicle according to the steady-state tire radius of the vehicle comprises: Obtaining the angular velocity of the wheel and the wheel end load of the wheel; Obtaining an expansion amount of the wheel according to an angular velocity of the wheel, a first preset parameter and a steady-state tire radius of the vehicle, wherein the first preset parameter is an adjustment coefficient of the tire radius; Obtaining a compression amount of the wheel according to a wheel end load of the wheel and a vertical stiffness of the wheel; The non-steady-state tire radius of the vehicle is calculated based on the steady-state tire radius of the vehicle, the expansion amount of the wheel, and the compression amount of the wheel.

7. The method according to claim 1 or 2, characterized in that: The method further comprises: When the driving parameter continuously indicates that the vehicle is in the steady-state driving within a second preset time period, the calculation of the steady-state tire radius of the vehicle is activated.

8. The method according to claim 1 or 2, characterized in that: The driving parameter includes at least one of the vehicle speed, the longitudinal acceleration of the vehicle, the longitudinal impact force of the chassis of the vehicle, the steering angle of the steering wheel of the vehicle, the slip rate of the vehicle, the lateral tilt angle of the vehicle and the longitudinal tilt angle of the vehicle, and the method further includes: When each of the driving parameters is within a corresponding preset range, determining that the driving parameters indicate that the vehicle is driving in the steady state; When one of the driving parameters is not within the corresponding preset range, it is determined that the driving parameter indicates that the vehicle is driving in a non-steady state.

9. A device for calculating the radius of a vehicle tire, characterized in that: The device comprises: An acquisition module is used to obtain the current driving parameters of the vehicle; A judgment module, used for judging the driving state of the vehicle according to the driving parameters of the vehicle at the current moment; The acquisition module is further used for determining a plurality of first preset time periods with the current time as the starting time when the driving parameter indicates that the vehicle is in steady-state driving, and acquiring the driving distance and wheel speed of the vehicle in each first preset time period; a calculation module, configured to perform an integral operation on the wheel speed based on the first preset time length to obtain a total number of wheel revolutions of the vehicle in each first preset time length; estimating the tire radius of the vehicle in each first preset time period according to the travel distance and the total number of wheel revolutions to obtain a plurality of tire radii; The plurality of tire radii are averaged to calculate a steady-state tire radius of the vehicle.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and when the computer program is executed, the method according to any one of claims 1 to 8 is implemented.

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