A vehicle speed calculation method, device and vehicle

Abstract

The present application relates to a vehicle speed calculation method, apparatus and vehicle. The method includes: determining a first speed of each wheel, where the first speed is used to indicate the speed of the rotation speed of each wheel converted to the center of mass of the current vehicle and in the driving direction; when it is determined that the current vehicle is on a potholed road, determining the driving state of the current vehicle and assigning corresponding weights according to the driving state; calculating the current vehicle speed based on the weights and the first speeds of the respective wheels. Using this method can improve the accuracy of vehicle speed calculation.

Description

Technical Field

[0001] This application relates to the technical field of vehicle control, and particularly to a vehicle speed calculation method, device, and vehicle. Background Art

[0002] Vehicle speed is an essential parameter for controlling and analyzing the driving state of a vehicle. For example, an on-vehicle electronic control unit can control the engine speed, identify the gear position, and perform functions such as cruise control based on the vehicle speed. Therefore, the accuracy and stability of the vehicle speed also directly determine the operation effects of these functions.

[0003] However, the existing methods for calculating vehicle speed through motor speed or electronic stability control system can obtain a relatively accurate vehicle speed only when the vehicle is stationary or driving at a constant speed on a consistent road condition, and it is difficult to adapt to the vehicle speed calculation scenarios of different road conditions and vehicle conditions.

[0004] Therefore, the accuracy of vehicle speed calculation in the prior art still needs to be improved. Summary of the Invention

[0005] Based on this, a vehicle speed calculation method, device, and vehicle are provided to improve the accuracy of vehicle speed calculation.

[0006] In a first aspect, a vehicle speed calculation method is provided. The method includes:

[0007] Determine the first speed of each wheel, where the first speed is used to indicate the speed of each wheel's rotation converted to the center of mass of the current vehicle and in the driving direction;

[0008] When it is determined that the current vehicle is on a potholed road, determine the driving state of the current vehicle and assign a corresponding weight according to the driving state;

[0009] Calculate the current vehicle speed based on the weight and the first speed of each wheel.

[0010] In combination with the first aspect, in the first possible implementation manner of the first aspect, the step of determining the first speed of each vehicle includes:

[0011] Obtain the wheelbase of the current vehicle;

[0012] Collect the yaw angular velocity and the current rotation speed of each wheel, where each wheel includes a left front wheel, a right front wheel, a left rear wheel, and a right rear wheel with the driving direction as the reference direction;

[0013] Obtain the wheel radius, and based on the wheel radius and each current rotation speed, obtain the second speed of each wheel;

[0014] Determine the corresponding first speed based on the wheelbase, the yaw rate, and the second speeds of the respective wheels.

[0015] Combined with the first implementable manner of the first aspect, in the second implementable manner of the first aspect, the step of determining the corresponding first speed based on the wheelbase, the yaw rate, and the second speeds of the respective wheels includes:

[0016] Collect the first rotation angle of the steering wheel;

[0017] Convert the first rotation angle into the second rotation angles of the respective wheels;

[0018] Set the center of mass of the current vehicle and obtain the first distance from the center of mass to the front axle of the current vehicle;

[0019] Obtain the first speed of the left front wheel according to the second rotation angles, the yaw rate, the wheelbase, the first distance, and the second speed of the left front wheel;

[0020] Obtain the first speed of the right front wheel according to the second rotation angles, the yaw rate, the wheelbase, the first distance, and the second speed of the right front wheel;

[0021] Obtain the first speed of the left rear wheel according to the yaw rate, the wheelbase, and the second speed of the left rear wheel;

[0022] Obtain the first speed of the right rear wheel according to the yaw rate, the wheelbase, and the second speed of the right rear wheel.

[0023] Combined with the first aspect, in the third implementable manner of the first aspect, before the step of determining the driving state of the current vehicle, it includes:

[0024] Obtain a preset first threshold, a second threshold, and a first duration;

[0025] Collect the current first acceleration of the current vehicle in the vertical direction;

[0026] Obtain the maximum speed change rate and the minimum speed change rate according to the first speeds of the respective wheels;

[0027] Compare the difference between the maximum speed change rate and the minimum speed change rate with the first threshold, and compare the current first acceleration with the second threshold;

[0028] When the difference is greater than or equal to the first threshold, the current first acceleration is greater than or equal to the second threshold, and it lasts for the first duration, determine that the road condition where the current vehicle is located is a potholed road surface.

[0029] Combined with the first aspect, in the fourth possible implementation manner of the first aspect, the step of determining the driving state of the current vehicle and allocating corresponding weights according to the driving state includes:

[0030] Collect the current second acceleration of the current vehicle in the driving direction;

[0031] Judge whether the current second acceleration is positive;

[0032] If so, determine that the driving state of the current vehicle is the driving state and allocate the weight in the driving state;

[0033] If not, determine that the driving state of the current vehicle is the braking state and allocate the weight in the braking state.

[0034] Combined with the fourth possible implementation manner of the first aspect, in the fifth possible implementation manner of the first aspect, the step of allocating the weight in the driving state includes:

[0035] Obtain the minimum speed and the minimum speed change rate according to the first speed of each wheel;

[0036] Obtain the historical vehicle speed, the historical second acceleration, and the preset operation cycle;

[0037] According to the operation cycle, the minimum speed, the historical vehicle speed, and the historical second acceleration, obtain a first value, and allocate the first value as the weight in the driving state, where the mathematical expression for obtaining the first value includes:

[0038]

[0039] A is the first value, t is the operation cycle, V min is the minimum speed, V estz is the historical vehicle speed, a escz is the historical second acceleration;

[0040] According to the operation cycle, the minimum speed change rate, the historical vehicle speed, and the historical second acceleration, obtain a second value, and allocate the second value as the weight in the driving state, where the mathematical expression for obtaining the second value includes:

[0041]

[0042] B is the second value, V minder is the minimum speed change rate.

[0043] Combined with the fifth implementable manner of the first aspect, in the sixth implementable manner of the first aspect, the step of calculating the current vehicle speed based on the weight and the first speed of each wheel includes:

[0044] Obtain a first product of the minimum speed and the first value, and a second product of the minimum speed change rate and the second value;

[0045] Obtain the current vehicle speed according to the sum value of the first product and the second product.

[0046] Combined with the fourth implementable manner of the first aspect, in the seventh implementable manner of the first aspect, the step of allocating the weight in the braking state includes:

[0047] Obtain the maximum speed and the maximum speed change rate according to the first speed of each wheel;

[0048] Obtain the historical vehicle speed, the historical second acceleration, and a preset operation period;

[0049] Obtain a third value according to the operation period, the maximum speed, the historical vehicle speed, and the historical second acceleration, and allocate the third value as the weight in the braking state, where the mathematical expression for obtaining the third value includes:

[0050]

[0051] C is the third value, t is the operation period, V max is the maximum speed, V estz is the historical vehicle speed, a escz is the historical second acceleration;

[0052] Obtain a fourth value according to the operation period, the maximum speed change rate, the historical vehicle speed, and the historical second acceleration, and allocate the fourth value as the weight in the braking state, where the mathematical expression for obtaining the fourth value includes:

[0053]

[0054] D is the fourth value, V maxder is the maximum speed change rate.

[0055] Combined with the seventh implementable manner of the first aspect, in the eighth implementable manner of the first aspect, the step of calculating the current vehicle speed based on the weight and the first speed of each wheel includes:

[0056] Obtain a third product of the maximum speed and the third value, and a fourth product of the maximum speed change rate and the fourth value;

[0057] Obtain the current vehicle speed based on the sum value of the third product and the fourth product.

[0058] Combined with the third implementable manner of the first aspect, in the ninth implementable manner of the first aspect, after the step of determining the first speed of each wheel, it further includes:

[0059] Collect the current second acceleration of the current vehicle in the driving direction;

[0060] Obtain a corresponding third acceleration based on the first speed of each wheel, and obtain the absolute value of the difference between each third acceleration and the current second acceleration;

[0061] Obtain a preset second duration, a third threshold, and a fourth threshold, determine whether each absolute value is greater than or equal to the third threshold, and continue for the second duration;

[0062] If so, determine that the confidence level of the first speed of the wheel pointed to by the absolute value is 0;

[0063] If not, determine that the confidence level of the first speed of the wheel pointed to by the absolute value is 1;

[0064] When the number of confidence levels of 1 is greater than or equal to the fourth threshold, execute the step of determining the driving state of the current vehicle and assigning corresponding weights according to the driving state.

[0065] In a second aspect, there is provided a vehicle speed calculation device, the device includes a vehicle controller, wherein the vehicle controller is configured to:

[0066] Determine the first speed of each wheel, wherein the first speed is used to indicate the speed of the rotation of each wheel converted to the center of mass of the current vehicle and in the driving direction;

[0067] When it is determined that the current vehicle is on a potholed road, determine the driving state of the current vehicle and assign corresponding weights according to the driving state;

[0068] Calculate the current vehicle speed based on the weights and the first speed of each wheel.

[0069] In a third aspect, there is provided a vehicle, the vehicle includes the vehicle speed calculation device as described in the second aspect, wherein the vehicle speed calculation device is configured to execute the vehicle speed calculation method as described in the first aspect or any implementable manner combined with the first aspect.

[0070] The above vehicle speed calculation method, device, and vehicle determine the first speed of each wheel, where the first speed is used to indicate the speed of the rotation of each wheel converted to the center of mass of the current vehicle and in the driving direction; and when it is determined that the current vehicle is on a potholed road, the driving state of the current vehicle is determined, and then corresponding weights are assigned according to the driving state; then, based on the assigned weights and the first speeds of each wheel, a weighted calculation is performed to obtain the current vehicle speed. It can be seen that the present application can assign different weights according to different driving states of the current vehicle on a potholed road, so as to calculate the vehicle speed in different driving states on a potholed road, improving the accuracy of vehicle speed calculation. BRIEF DESCRIPTION OF THE DRAWINGS

[0071] Figure 1 It is a schematic flowchart of the vehicle speed calculation method in the first embodiment;

[0072] Figure 2 It is a structural block diagram of the vehicle speed calculation device in the second embodiment;

[0073] Figure 3 It is a structural block diagram of the vehicle speed calculation device in the second embodiment;

[0074] Figure 4 It is a structural block diagram of the vehicle speed calculation device in the second embodiment;

[0075] Figure 5 It is a structural block diagram of the vehicle speed calculation device in the second embodiment. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0076] In order to make the objectives, technical solutions, and advantages of the present application clearer, the present application will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0077] It should be noted that the diagrams provided in this embodiment only illustrate the basic concept of the present application schematically. Therefore, only the components related to the present application are shown in the diagrams, rather than being drawn according to the number, shape, and size of the components in actual implementation. The type, quantity, and ratio of each component in actual implementation can be arbitrarily changed, and the component layout type may also be more complex.

[0078] The structures, ratios, sizes, etc. shown in the drawings of this specification are only used to cooperate with the content disclosed in the specification for those skilled in the art to understand and read, and are not used to limit the limiting conditions under which the present application can be implemented. Therefore, they do not have a technical essence. Any modification of the structure, change in the proportional relationship, or adjustment of the size, without affecting the effects that the present application can produce and the objectives that can be achieved, should still fall within the scope that can be covered by the technical content disclosed in the present application.

[0079] The orientation or positional relationship indicated by terms such as "upper", "lower", "left", "right", "middle", "longitudinal", "lateral", "horizontal", "inner", "outer", "radial", "circumferential", etc. cited in this specification is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of simplified description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be construed as a limitation to this application. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0080] Currently, vehicle speed is an essential parameter for controlling and analyzing the driving state of a vehicle, and the accuracy and stability of the vehicle speed also determine to a certain extent the operation effect of various functions on the vehicle. However, in the prior art, the method of calculating the vehicle speed through the motor speed or the electronic stability control system can only obtain a relatively accurate vehicle speed when the vehicle is stationary or driving at a constant speed on a flat road condition, and it is difficult to adapt to the vehicle speed calculation scenarios of other road conditions or vehicle conditions, such as potholed roads. Therefore, the accuracy of vehicle speed calculation in the prior art still needs to be improved.

[0081] For this reason, this application proposes a vehicle speed calculation method, by determining the first speed of each wheel, where the first speed is used to indicate the speed of the rotation speed of each wheel converted to the centroid of the current vehicle and in the driving direction; and different weights are assigned according to the different driving states of the current vehicle on a potholed road, so as to calculate the vehicle speed in different driving states of the vehicle on a potholed road and improve the accuracy of vehicle speed calculation.

[0082] In one embodiment, as Figure 1 shown, a vehicle speed calculation method is provided. Taking the execution subject of this method as the vehicle controller as an example for illustration, it includes the following steps:

[0083] S1: Determine the first speed of each wheel, where the first speed is used to indicate the speed of the rotation speed of each wheel converted to the centroid of the current vehicle and in the driving direction.

[0084] In an implementable manner, specifically, the step of determining the first speed of each wheel includes: obtaining the wheelbase of the current vehicle; collecting the yaw angular velocity and the current rotation speed of each wheel, where, taking the driving direction as the reference direction, each wheel includes the left front wheel, the right front wheel, the left rear wheel, and the right rear wheel; obtaining the wheel radius, and obtaining the second speed of each wheel according to the wheel radius and each current rotation speed; and determining the corresponding first speed based on the wheelbase, the yaw angular velocity, and the second speed of each wheel.

[0085] It should be noted that the yaw rate and the current rotational speed can be collected by a speed sensor. Among them, the positive or negative value of the yaw rate is related to the steering direction of the current vehicle. Taking the driving direction of the current vehicle as the reference direction, if the steering direction is to the left, the yaw rate is negative, and if the steering direction is to the right, the yaw rate is positive. In this embodiment, the second speed of each wheel is calculated based on the wheel radius and the corresponding current rotational speed. Among them, the mathematical expression for calculating the second speed includes: v wl_xx = 2πN xx R / 60, v wl_xx is used to indicate the second speed of a specific wheel. By way of example, v wl_fl is used to indicate the second speed of the left front wheel, v wl_fr is used to indicate the second speed of the right front wheel, v wl_rl is used to indicate the second speed of the left rear wheel, v wl_rr is used to indicate the second speed of the right rear wheel. In other embodiments, other symbols can also be used; N xx is used to indicate the current rotational speed of a specific wheel. For example, taking the symbols of the aforementioned wheels as an example, N fl is used to indicate the current rotational speed of the left front wheel, N fr is used to indicate the current rotational speed of the right front wheel, N rl is used to indicate the current rotational speed of the left rear wheel, N rr is used to indicate the current rotational speed of the right rear wheel; π is the pi, and R is the wheel radius. In other embodiments, the second speed of each wheel, that is, the wheel speed of each wheel, can also be directly collected by a speed sensor or an Electronic Stability Controller (ESC).

[0086] Further, the step of determining the corresponding first speed based on the wheelbase, the yaw rate, and the second speed of each wheel includes: collecting the first rotation angle of the steering wheel; converting the first rotation angle into the second rotation angle of each wheel; setting the center of mass of the current vehicle and obtaining the first distance from the center of mass to the front axle of the current vehicle; obtaining the first speed of the left front wheel according to the second rotation angle, the yaw rate, the wheelbase, the first distance, and the second speed of the left front wheel; obtaining the first speed of the right front wheel according to the second rotation angle, the yaw rate, the wheelbase, the first distance, and the second speed of the right front wheel; obtaining the first speed of the left rear wheel according to the yaw rate, the wheelbase, and the second speed of the left rear wheel; obtaining the first speed of the right rear wheel according to the yaw rate, the wheelbase, and the second speed of the right rear wheel.

[0087] It should be noted that, taking the driving direction of the current vehicle as the reference direction, the first rotation angle of the steering wheel refers to the angle of the steering wheel turning to the left or right relative to the straight driving direction; the second rotation angle refers to the angle of each wheel turning to the left or right relative to the straight driving direction when the steering wheel turns according to the first rotation angle; the step of converting the first rotation angle into the second rotation angle of each wheel refers to: obtaining a preset first mapping table, searching in the first mapping table based on the first rotation angle, and obtaining the corresponding second rotation angle. Among them, the first mapping table is used to indicate the relationship between the first rotation angle and the second rotation angle, and if the steering wheel turns to the left, the second rotation angle is a positive value, and if the steering wheel turns to the right, the second rotation angle is a negative value.

[0088] Among them, the mathematical expression for obtaining the first speed of the left front wheel includes: v xfl is the first speed of the left front wheel, v wl_fl is the second speed of the left front wheel, δ is the second rotation angle, γ is the yaw angular velocity, L w is the track width, L a is the first distance; the mathematical expression for obtaining the first speed of the right front wheel includes: v xfr is the first speed of the right front wheel, v wl_fr is the second speed of the right front wheel, δ is the second rotation angle, γ is the yaw angular velocity, L w is the track width, L a is the first distance; the mathematical expression for obtaining the first speed of the left rear wheel includes: v xrl is the first speed of the left rear wheel, v wl_rl is the second speed of the left rear wheel, γ is the yaw angular velocity, L w is the track width; the mathematical expression for obtaining the first speed of the right rear wheel includes: v xrr is the first speed of the right rear wheel, v wl_rr is the second speed of the right rear wheel, γ is the yaw angular velocity, L w is the track width.

[0089] S2: When it is determined that the current vehicle is on a potholed road, determine the driving state of the current vehicle and allocate corresponding weights according to the driving state.

[0090] In an implementable manner, before determining the driving state of the current vehicle, it is also necessary to determine whether the road condition where the current vehicle is located is a potholed road surface. If so, the vehicle speed calculation method described in this application is applied on the potholed road, improving the phenomenon in the prior art that it is difficult to be compatible with other road conditions, resulting in low accuracy of vehicle speed calculation. Specifically, the steps of determining whether the road where the current vehicle is located is a potholed road surface include: obtaining a preset first threshold, a second threshold, and a first duration; collecting the current first acceleration of the current vehicle in the vertical direction; obtaining the maximum speed change rate and the minimum speed change rate based on the first speeds of the respective wheels; comparing the difference between the maximum speed change rate and the minimum speed change rate with the first threshold, and comparing the current first acceleration with the second threshold; when the difference is greater than or equal to the first threshold, the current first acceleration is greater than or equal to the second threshold, and this state lasts for the first duration, it is determined that the road condition where the current vehicle is located is a potholed road surface. Among them, the maximum speed change rate refers to: taking the derivative of the maximum speed among the respective first speeds to obtain the change rate of this maximum speed; the minimum speed change rate refers to: taking the derivative of the minimum speed among the respective first speeds to obtain the change rate of this minimum speed; the first threshold and the second threshold can be obtained through skid tests of the actual vehicle on a potholed road surface. By way of example, the first threshold can be set to 2.

[0091] In an implementable manner, by identifying whether the driving state of the current vehicle is a driving state or a braking state, and different weights are assigned in the driving state and the braking state. Specifically, it includes: collecting the current second acceleration of the current vehicle in the driving direction; determining whether the current second acceleration is positive; if so, determining that the driving state of the current vehicle is the driving state and assigning the weight in the driving state; if not, determining that the driving state of the current vehicle is the braking state and assigning the weight in the braking state.

[0092] Further, the steps of assigning the weight in the driving state include: obtaining the minimum speed and the minimum speed change rate based on the first speeds of the respective wheels; obtaining the historical vehicle speed, the historical second acceleration, and a preset operation period; obtaining a first value based on the operation period, the minimum speed, the historical vehicle speed, and the historical second acceleration, and assigning the first value as the weight in the driving state. Among them, the mathematical expression for obtaining the first value includes:

[0093]

[0094] A is the first value, t is the operation period, V min is the minimum speed, V estz is the historical vehicle speed, aescz is the historical second acceleration; obtaining a second value according to the operation period, the minimum speed change rate, the historical vehicle speed, and the historical second acceleration, and assigning the second value as the weight in the driving state, where the mathematical expression for obtaining the second value includes:

[0095]

[0096] B is the second value, V minder is the minimum speed change rate.

[0097] The steps of assigning the weight in the braking state include: obtaining the maximum speed and the maximum speed change rate according to the first speed of each wheel; obtaining the historical vehicle speed, the historical second acceleration, and a preset operation period; obtaining a third value according to the operation period, the maximum speed, the historical vehicle speed, and the historical second acceleration, and assigning the third value as the weight in the braking state, where the mathematical expression for obtaining the third value includes:

[0098]

[0099] C is the third value, t is the operation period, V max is the maximum speed, V estz is the historical vehicle speed, a escz is the historical second acceleration; obtaining a fourth value according to the operation period, the maximum speed change rate, the historical vehicle speed, and the historical second acceleration, and assigning the fourth value as the weight in the braking state, where the mathematical expression for obtaining the fourth value includes:

[0100]

[0101] D is the fourth value, V maxder is the maximum speed change rate.

[0102] Among them, the minimum speed refers to: the minimum speed among each first speed; the minimum speed change rate refers to: the change rate of the minimum speed obtained by taking the derivative of the minimum speed; the historical vehicle speed refers to: the vehicle speed calculated at the previous moment one operation period away from the current moment; the historical second acceleration refers to: the second acceleration of the current vehicle in the driving direction collected at the previous moment one operation period away from the current moment; the operation period can be set to 10 ms; the maximum speed refers to: the maximum speed among each first speed; the maximum speed change rate refers to: the change rate of the maximum speed obtained by taking the derivative of the maximum speed.

[0103] S3: Calculate the current vehicle speed based on the weights and the first speeds of the respective wheels.

[0104] In an applicable scenario, if the current driving state of the vehicle is the driving state, calculate the current vehicle speed based on the first value, the second value, and the first speeds of the respective wheels in this scenario. The specific steps include: obtaining the first product of the minimum speed and the first value, and the second product of the minimum speed change rate and the second value; obtaining the current vehicle speed according to the sum value of the first product and the second product. Here, the minimum speed is used to indicate the minimum speed among the first speeds of the respective wheels.

[0105] In another applicable scenario, if the current driving state of the vehicle is the braking state, calculate the current vehicle speed by weighted calculation based on the third value, the fourth value, and the first speeds of the respective wheels in this scenario. The specific steps include: obtaining the third product of the maximum speed and the third value, and the fourth product of the maximum speed change rate and the fourth value; obtaining the current vehicle speed according to the sum value of the third product and the fourth product. Here, the maximum speed is used to indicate the maximum speed among the first speeds of the respective wheels.

[0106] In a preferred implementation manner, the confidence level of the first speed can also be combined to determine whether it is necessary to use the weighted calculation method to obtain the current vehicle speed. Specifically, after the step of determining the first speeds of the respective wheels, it further includes: collecting the current second acceleration of the current vehicle in the driving direction; obtaining the corresponding third acceleration according to the first speeds of the respective wheels, and obtaining the absolute value of the difference between each third acceleration and the current second acceleration; obtaining a preset second duration, a third threshold, and a fourth threshold, and determining whether each absolute value is greater than or equal to the third threshold and lasting for the second duration; if so, determining that the confidence level of the first speed of the wheel pointed to by the absolute value is 0; if not, determining that the confidence level of the first speed of the wheel pointed to by the absolute value is 1; when the number of confidence levels of 1 is greater than or equal to the fourth threshold, execute the step of determining the driving state of the current vehicle and allocating corresponding weights according to the driving state.

[0107] It should be noted that the step of obtaining the corresponding third acceleration according to the first speed of each wheel refers to: taking the derivative of the first speed to obtain the change rate of the first speed, that is, the third acceleration; the third threshold and the second duration can be determined by performing a skid test on the whole vehicle, and the third threshold can be set to 2; the fourth threshold can be set to 1. If the number of confidences of 1 is less than the fourth threshold, that is, less than 1, the execution of the step ends. When the confidence is 0, it is considered that the first speed of the wheel it points to is not credible. When the confidence is 1, it is considered that the first speed of the wheel it points to is credible. For example, if the absolute value of the difference between the third acceleration of the left front wheel and the current second acceleration is greater than or equal to the third threshold and lasts for the second duration, it is determined that the confidence of the first speed of the left front wheel is 0, and it is considered that the first speed of the left front wheel is not credible; if the absolute value of the difference between the third acceleration of the left front wheel and the current second acceleration is less than the third threshold, it is determined that the confidence of the first speed of the left front wheel is 1, and it is considered that the first speed of the left front wheel is credible.

[0108] In summary, the present application determines the first speed of each wheel; and assigns different weights according to different driving states of the current vehicle on a potholed road, so as to calculate the vehicle speed under different driving states of the vehicle on a potholed road, improving the accuracy of vehicle speed calculation.

[0109] It should be understood that although Figure 1 the steps in the flowchart of Figure 1 are shown in sequence according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless otherwise clearly stated in this article, the execution of these steps has no strict order limit, and these steps can be executed in other orders. Moreover,

[0110] In the second embodiment, a vehicle speed calculation device is provided, including: a vehicle controller, wherein the vehicle controller is configured to:

[0111] Determine the first speed of each wheel, where the first speed is used to indicate the speed of the rotation speed of each wheel converted to the center of mass of the current vehicle and in the driving direction;

[0112] When it is determined that the current vehicle is on a potholed road, determine the driving state of the current vehicle, and assign corresponding weights according to the driving state;

[0113] Calculate the current vehicle speed based on the weights and the first speeds of the respective wheels.

[0114] Preferably, referring to Figure 2 , the device may further include a first speed sensor, wherein the first speed sensor is electrically connected to the vehicle controller. On this basis, the steps for the vehicle controller to determine the first speed of each wheel include: obtaining the wheelbase of the current vehicle; collecting the yaw angular velocity and the current rotational speeds of the respective wheels through the first speed sensor, wherein, with the driving direction as the reference direction, the respective wheels include the left front wheel, the right front wheel, the left rear wheel, and the right rear wheel; obtaining the wheel radius, and obtaining the second speed of each wheel according to the wheel radius and the respective current rotational speeds; and determining the corresponding first speed based on the wheelbase, the yaw angular velocity, and the second speed of each wheel. Among them, there may be 5 first speed sensors, and the 5 first speed sensors are respectively used to collect the yaw angular velocity, the current rotational speeds of the left front wheel, the right front wheel, the left rear wheel, and the right rear wheel.

[0115] Preferably, referring to Figure 3 , the device may further include an angular displacement sensor, wherein the angular displacement sensor is electrically connected to the vehicle controller. On this basis, the steps for the vehicle controller to determine the corresponding first speed based on the wheelbase, the yaw angular velocity, and the second speed of each wheel include: collecting the first rotation angle of the steering wheel through the angular displacement sensor; converting the first rotation angle into the second rotation angles of the respective wheels; setting the center of mass of the current vehicle, and obtaining the first distance from the center of mass to the front axle of the current vehicle; obtaining the first speed of the left front wheel according to the second rotation angle, the yaw angular velocity, the wheelbase, the first distance, and the second speed of the left front wheel; obtaining the first speed of the right front wheel according to the second rotation angle, the yaw angular velocity, the wheelbase, the first distance, and the second speed of the right front wheel; obtaining the first speed of the left rear wheel according to the yaw angular velocity, the wheelbase, and the second speed of the left rear wheel; and obtaining the first speed of the right rear wheel according to the yaw angular velocity, the wheelbase, and the second speed of the right rear wheel.

[0116] Preferably, referring to Figure 4, the device may further include a second speed sensor, wherein the second speed sensor is electrically connected to the vehicle controller. On this basis, before the step of determining the driving state of the current vehicle, the vehicle controller is further configured to: obtain a preset first threshold, a second threshold, and a first duration; collect the current first acceleration of the current vehicle in the vertical direction through the second speed sensor; obtain the maximum speed change rate and the minimum speed change rate according to the first speeds of the respective wheels; compare the difference between the maximum speed change rate and the minimum speed change rate with the first threshold, and compare the current first acceleration with the second threshold; when the difference is greater than or equal to the first threshold, the current first acceleration is greater than or equal to the second threshold, and the first duration is continuously maintained, determine that the road condition where the current vehicle is located is a potholed road surface.

[0117] Preferably, referring to Figure 5 , the device may further include a third speed sensor, wherein the third speed sensor is electrically connected to the vehicle controller. On this basis, the step in which the vehicle controller determines the driving state of the current vehicle and allocates corresponding weights according to the driving state includes: collecting the current second acceleration of the current vehicle in the driving direction through the third speed sensor; determining whether the current second acceleration is positive; if so, determining that the driving state of the current vehicle is the driving state and allocating the weight in the driving state; if not, determining that the driving state of the current vehicle is the braking state and allocating the weight in the braking state.

[0118] Specifically, in an applicable scenario, the step in which the vehicle controller allocates the weight in the driving state includes: obtaining the minimum speed and the minimum speed change rate according to the first speeds of the respective wheels; obtaining the historical vehicle speed, the historical second acceleration, and a preset operation period; obtaining a first value according to the operation period, the minimum speed, the historical vehicle speed, and the historical second acceleration, and allocating the first value as the weight in the driving state, wherein the mathematical expression for obtaining the first value includes:

[0119]

[0120] A is the first value, t is the operation period, V min is the minimum speed, V estz is the historical vehicle speed, a esczis the historical second acceleration; obtaining a second value according to the operation period, the minimum speed change rate, the historical vehicle speed, and the historical second acceleration, and allocating the second value as the weight in the driving state, where the mathematical expression for obtaining the second value includes:

[0121]

[0122] B is the second value, V minder is the minimum speed change rate.

[0123] Further, the step of the vehicle controller calculating the current vehicle speed based on the weight and the first speed of each wheel includes: obtaining a first product of the minimum speed and the first value, and a second product of the minimum speed change rate and the second value; obtaining the current vehicle speed according to the sum value of the first product and the second product.

[0124] In another applicable scenario, the step of the vehicle controller allocating the weight in the braking state includes: obtaining the maximum speed and the maximum speed change rate according to the first speed of each wheel; obtaining the historical vehicle speed, the historical second acceleration, and a preset operation period; obtaining a third value according to the operation period, the maximum speed, the historical vehicle speed, and the historical second acceleration, and allocating the third value as the weight in the braking state, where the mathematical expression for obtaining the third value includes:

[0125]

[0126] C is the third value, t is the operation period, V max is the maximum speed, V estz is the historical vehicle speed, a escz is the historical second acceleration; obtaining a fourth value according to the operation period, the maximum speed change rate, the historical vehicle speed, and the historical second acceleration, and allocating the fourth value as the weight in the braking state, where the mathematical expression for obtaining the fourth value includes:

[0127]

[0128] D is the fourth value, V maxder is the maximum speed change rate.

[0129] Further, the step of the vehicle controller calculating the current vehicle speed based on the weight and the first speed of each wheel includes: obtaining a third product of the maximum speed and the third value, and a fourth product of the maximum speed change rate and the fourth value; obtaining the current vehicle speed according to the sum value of the third product and the fourth product.

[0130] Preferably, after the step of determining the first speed of each wheel, the vehicle controller is further configured to: collect the current second acceleration of the current vehicle in the driving direction through the third speed sensor; obtain the corresponding third acceleration according to the first speed of each wheel, and obtain the absolute value of the difference between each third acceleration and the current second acceleration; obtain a preset second duration, and determine whether each absolute value is greater than or equal to the third threshold and continue for the second duration; if so, determine that the confidence level of the first speed of the wheel pointed to by the absolute value is 0; if not, determine that the confidence level of the first speed of the wheel pointed to by the absolute value is 1; when the number of confidence levels of 1 is greater than or equal to a preset fourth threshold, execute the step of determining the driving state of the current vehicle and allocating corresponding weights according to the driving state.

[0131] For the specific limitations of the vehicle speed calculation device, reference may be made to the limitations of the vehicle speed calculation method in the foregoing text, which will not be elaborated here.

[0132] In the third embodiment, a vehicle is provided, where the vehicle includes the vehicle speed calculation device as described in the second embodiment, and the vehicle speed calculation device is configured to execute the vehicle speed calculation method as described in the first embodiment.

[0133] Those of ordinary skill in the art can understand that all or part of the processes in the methods of the above embodiments can be completed by instructing relevant hardware through a computer program. The computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above methods. Among them, any reference to a memory, storage, database, or other medium used in the embodiments provided in the present application can include non-volatile and / or volatile memories. Non-volatile memories can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), or flash memory. Volatile memories can include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in many forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDR SDRAM), enhanced SDRAM (ESDRAM), synchronous link DRAM (SLDRAM), Rambus direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and Rambus dynamic RAM (RDRAM), etc.

[0134] The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope described in this specification.

[0135] The above-described embodiments merely represent several implementation manners of the present application. The description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several modifications and improvements can still be made, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the appended claims.

Claims

1. A vehicle speed calculation method, characterized in that, Including: Determine the first speed of each wheel, where the first speed is used to indicate the speed of the rotation speed of each wheel converted to the center of mass of the current vehicle and in the driving direction; When it is determined that the current vehicle is on a potholed road, determine the driving state of the current vehicle and assign corresponding weights according to the driving state; Based on the weights and the first speeds of the respective wheels, calculate the current vehicle speed; The step of determining that the current vehicle is on a potholed road includes: Obtain a preset first threshold, second threshold, and first duration; Collect the current first acceleration of the current vehicle in the vertical direction; Based on the first speeds of the respective wheels, obtain the maximum speed change rate and the minimum speed change rate; Compare the difference between the maximum speed change rate and the minimum speed change rate with the first threshold, and compare the current first acceleration with the second threshold; When the difference is greater than or equal to the first threshold, the current first acceleration is greater than or equal to the second threshold, and this continues for the first duration, determine that the road condition where the current vehicle is located is a potholed road surface.

2. The vehicle speed calculation method according to claim 1, characterized in that The step of determining the first speed of each vehicle includes: Obtain the wheelbase of the current vehicle; Collect the yaw angular velocity and the current rotation speeds of the respective wheels, where, with the driving direction as the reference direction, the respective wheels include the left front wheel, right front wheel, left rear wheel, and right rear wheel; Obtain the wheel radius, and based on the wheel radius and the respective current rotation speeds, obtain the second speed of each wheel; Based on the wheelbase, the yaw angular velocity, and the second speeds of the respective wheels, determine the corresponding first speed.

3. The vehicle speed calculation method according to claim 2, characterized in that, The step of determining the corresponding first speed based on the wheelbase, the yaw angular velocity, and the second speeds of the respective wheels includes: Collect the first rotation angle of the steering wheel; Convert the first rotation angle to the second rotation angles of the respective wheels; Set the center of mass of the current vehicle and obtain the first distance from the center of mass to the front axle of the current vehicle; Based on the second rotation angle, the yaw angular velocity, the wheelbase, the first distance, and the second speed of the left front wheel, obtain the first speed of the left front wheel; Based on the second rotation angle, the yaw angular velocity, the wheelbase, the first distance, and the second speed of the right front wheel, obtain the first speed of the right front wheel; Based on the yaw angular velocity, the wheelbase, and the second speed of the left rear wheel, obtain the first speed of the left rear wheel; Based on the yaw angular velocity, the wheelbase, and the second speed of the right rear wheel, obtain the first speed of the right rear wheel.

4. The vehicle speed calculation method according to claim 1, characterized in that The step of determining the driving state of the current vehicle and assigning corresponding weights according to the driving state includes: Collect the current second acceleration of the current vehicle in the driving direction; Judge whether the current second acceleration is positive; If so, determine that the driving state of the current vehicle is the driving state and assign the weight in the driving state; If not, determine that the driving state of the current vehicle is the braking state and assign the weight in the braking state.

5. The vehicle speed calculation method according to claim 4, wherein The step of allocating the weight in the driving state includes: Obtaining the minimum speed and the minimum speed change rate according to the first speeds of the respective wheels; Obtaining the historical vehicle speed, the historical second acceleration, and a preset operation period; Obtaining a first value according to the operation period, the minimum speed, the historical vehicle speed, and the historical second acceleration, and allocating the first value as the weight in the driving state, wherein the mathematical expression for obtaining the first value includes: A is the first numerical value, t is the operating cycle, V min is the minimum speed, V estz is the historical vehicle speed, a escz is the historical second acceleration; Obtaining a second value according to the operation period, the minimum speed change rate, the historical vehicle speed, and the historical second acceleration, and allocating the second value as the weight in the driving state, wherein the mathematical expression for obtaining the second value includes: B is the second value, V minder is the minimum rate of change of speed.

6. The vehicle speed calculation method according to claim 5, characterized in that, The step of calculating the current vehicle speed based on the weight and the first speeds of the respective wheels includes: Obtaining a first product of the minimum speed and the first value, and a second product of the minimum speed change rate and the second value; Obtaining the current vehicle speed according to the sum value of the first product and the second product.

7. The vehicle speed calculation method according to claim 4, wherein The step of allocating the weight in the braking state includes: Obtaining the maximum speed and the maximum speed change rate according to the first speeds of the respective wheels; Obtaining the historical vehicle speed, the historical second acceleration, and a preset operation period; Obtaining a third value according to the operation period, the maximum speed, the historical vehicle speed, and the historical second acceleration, and allocating the third value as the weight in the braking state, wherein the mathematical expression for obtaining the third value includes: C is the third value, t is the operating cycle, V max is the maximum speed, V estz is the historical vehicle speed, a escz is the historical second acceleration; Obtaining a fourth value according to the operation period, the maximum speed change rate, the historical vehicle speed, and the historical second acceleration, and allocating the fourth value as the weight in the braking state, wherein the mathematical expression for obtaining the fourth value includes: D is the fourth value, and V maxder is the maximum rate of speed change.

8. The vehicle speed calculation method according to claim 7, wherein The step of calculating the current vehicle speed based on the weight and the first speeds of the respective wheels includes: Obtaining a third product of the maximum speed and the third value, and a fourth product of the maximum speed change rate and the fourth value; Obtaining the current vehicle speed according to the sum value of the third product and the fourth product.

9. The vehicle speed calculation method according to claim 1, characterized in that After the step of determining the first speeds of the respective wheels, it further includes: Collecting the current second acceleration of the current vehicle in the driving direction; Obtaining the corresponding third acceleration according to the first speeds of the respective wheels, and obtaining the absolute value of the difference between each third acceleration and the current second acceleration; Obtaining a preset second duration, a third threshold, and a fourth threshold, and determining whether each absolute value is greater than or equal to the third threshold and lasting for the second duration; If so, determining that the confidence level of the first speed of the wheel pointed to by the absolute value is 0; If not, determining that the confidence level of the first speed of the wheel pointed to by the absolute value is 1; When the number of confidence levels of 1 is greater than or equal to the fourth threshold, performing the step of determining the driving state of the current vehicle and allocating the corresponding weight according to the driving state.

10. A vehicle speed calculation device, characterized in that, The device includes a vehicle controller, wherein the vehicle controller is configured to: Determine a first speed of each wheel, where the first speed is used to indicate the speed of the rotation of each wheel converted to the center of mass of the current vehicle and in the driving direction; When it is determined that the current vehicle is on a potholed road, determine the driving state of the current vehicle and assign corresponding weights according to the driving state; Calculate the current vehicle speed based on the weights and the first speeds of the respective wheels; The step of determining that the current vehicle is on a potholed road includes: Obtain a preset first threshold, second threshold, and first duration; Collect a current first acceleration of the current vehicle in the vertical direction; Obtain a maximum speed change rate and a minimum speed change rate based on the first speeds of the respective wheels; Compare the difference between the maximum speed change rate and the minimum speed change rate with the first threshold, and compare the current first acceleration with the second threshold; When the difference is greater than or equal to the first threshold, the current first acceleration is greater than or equal to the second threshold, and this continues for the first duration, determine that the road condition where the current vehicle is located is a potholed road surface.

11. A vehicle, characterized in that, The vehicle includes a vehicle speed calculation device as claimed in claim 10, wherein the vehicle speed calculation device is configured to perform the vehicle speed calculation method as claimed in any one of claims 1-9.

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