Longitudinal vehicle speed estimation method, device, equipment and medium

Abstract

The present invention relates to the field of vehicle driving control technology, and in particular to a longitudinal vehicle speed estimation method, device, equipment and medium. The yaw angular velocity and vehicle acceleration collected in the current cycle, as well as the estimated longitudinal resultant force and the estimated lateral resultant force are input into a vehicle speed observation model to obtain the real-time longitudinal estimated vehicle speed of the current cycle. The historical wheel speeds collected in the previous cycle and the real-time wheel speeds are input into a vehicle speed measurement model to obtain the real-time longitudinal measured vehicle speed of the current cycle. The real-time longitudinal estimated vehicle speed and the real-time longitudinal measured vehicle speed are weightedly fused to obtain the actual longitudinal vehicle speed of the current cycle. In this application, the real-time longitudinal estimated vehicle speed is fused with the vehicle speed measurement value based on the wheel speed to improve the accuracy of the longitudinal vehicle speed estimation and the applicability to different working conditions, provide accurate longitudinal vehicle speed input for the vehicle control system, and improve the control effect.

Description

Technical Field

[0001] The present invention relates to the technical field of vehicle driving control, and in particular to a method, device, equipment and medium for estimating longitudinal vehicle speed. Background Art

[0002] Estimating a vehicle's longitudinal speed is fundamental to its driving state estimation and control. Applications such as slip rate calculation, center of mass side slip angle estimation, anti-lock braking (ABS), anti-slip control, and stability control all require longitudinal speed information. Unlike wheel speed or acceleration, longitudinal speed cannot be measured with simple sensors. Direct measurement is typically very expensive, making it impractical for widespread use in vehicles. Furthermore, as a fundamental vehicle state variable, many vehicle characteristics are correlated with longitudinal speed, placing high demands on both real-time and accuracy. Accurate longitudinal speed estimation facilitates further calculations of other vehicle driving states and improves the effectiveness of control systems.

[0003] According to the sensors currently installed on vehicles, longitudinal vehicle speed estimation mainly uses wheel speed signals and longitudinal acceleration signals. When there is no obvious wheel slip or wheel speed fluctuation, the wheel speed signal can be used to calculate the longitudinal vehicle speed well. However, when the wheel is obviously slipping or locking, or the wheel speed fluctuates significantly due to the road surface or steering, it is difficult to obtain an accurate longitudinal vehicle speed using only the wheel speed signal.

[0004] Therefore, in the process of estimating the longitudinal velocity of the vehicle, how to improve the accuracy of estimating the longitudinal velocity of the vehicle becomes an urgent problem to be solved. Summary of the Invention

[0005] Based on this, it is necessary to provide a longitudinal vehicle speed estimation method, device, equipment and medium to address the above technical issues, so as to solve the problem of low accuracy in estimating the longitudinal speed of the vehicle during the process of estimating the longitudinal speed of the vehicle.

[0006] A first aspect of an embodiment of the present application provides a method for estimating longitudinal vehicle speed, comprising:

[0007] The real-time wheel speed collected in the current cycle and the historical lateral estimated vehicle speed and historical longitudinal estimated vehicle speed obtained by the vehicle speed observation model in the previous cycle are input into the tire model to obtain the estimated longitudinal force and estimated lateral force of the current cycle;

[0008] Inputting the yaw rate and vehicle acceleration collected in the current cycle, the historical lateral estimated vehicle speed and historical longitudinal estimated vehicle speed, and the estimated longitudinal resultant force and estimated lateral resultant force in the current cycle into the vehicle speed observation model to obtain the real-time longitudinal estimated vehicle speed in the current cycle;

[0009] The historical wheel speed collected in the previous cycle and the real-time wheel speed are input into the vehicle speed measurement model to obtain the real-time longitudinal measured vehicle speed of the current cycle, and the real-time longitudinal estimated vehicle speed and the real-time longitudinal measured vehicle speed are weightedly fused to obtain the actual longitudinal vehicle speed of the current cycle.

[0010] A second aspect of an embodiment of the present application provides a device for estimating longitudinal vehicle speed, comprising:

[0011] A first obtaining module is configured to input the real-time wheel speed collected in the current cycle and the historical lateral estimated vehicle speed and historical longitudinal estimated vehicle speed obtained by the vehicle speed observation model in the previous cycle into the tire model to obtain the estimated longitudinal resultant force and the estimated lateral resultant force of the current cycle;

[0012] a second obtaining module, configured to input the yaw angular velocity and vehicle acceleration collected in the current cycle, the historical lateral estimated vehicle speed and the historical longitudinal estimated vehicle speed, and the estimated longitudinal resultant force and the estimated lateral resultant force in the current cycle into the vehicle speed observation model to obtain the real-time longitudinal estimated vehicle speed in the current cycle;

[0013] A fusion module is used to input the historical wheel speed collected in the previous cycle and the real-time wheel speed into a vehicle speed measurement model to obtain the real-time longitudinal measured vehicle speed of the current cycle, and to perform weighted fusion on the real-time longitudinal estimated vehicle speed and the real-time longitudinal measured vehicle speed to obtain the actual longitudinal vehicle speed of the current cycle.

[0014] A third aspect of an embodiment of the present application provides a computer device, comprising a processor, a memory, and a computer program stored in the memory and executable on the processor, wherein the computer device is configured to implement the longitudinal vehicle speed estimation method described in any one of the first aspects when executed.

[0015] A fourth aspect of an embodiment of the present application provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the longitudinal vehicle speed estimation method described in any one of the first aspects is implemented.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] The real-time wheel speed collected in the current cycle and the historical lateral estimated speed and historical longitudinal estimated speed obtained by the speed observation model in the previous cycle are input into the tire model to obtain the estimated longitudinal resultant force and estimated lateral resultant force of the current cycle, the yaw angular velocity and vehicle acceleration collected in the current cycle, the historical lateral estimated speed and historical longitudinal estimated speed, and the estimated longitudinal resultant force and estimated lateral resultant force of the current cycle are input into the speed observation model to obtain the real-time longitudinal estimated speed of the current cycle, the historical wheel speed and real-time wheel speed collected in the previous cycle are input into the speed measurement model to obtain the real-time longitudinal measured speed of the current cycle, the real-time longitudinal estimated speed and the real-time longitudinal measured speed are weightedly fused to obtain the actual longitudinal speed of the current cycle. In this application, the real-time longitudinal estimated speed is fused with the speed measurement value based on the wheel speed to improve the accuracy of the longitudinal speed estimation and the applicability of different working conditions, provide accurate longitudinal speed input for the vehicle control system, and improve the control effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments of the present invention. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0019] Figure 1 1 is a flow chart of a method for estimating longitudinal vehicle speed provided in the first embodiment of the present invention;

[0020] Figure 2 This is a tire position structure diagram of a vehicle provided by the second embodiment of the present invention;

[0021] Figure 3 This is a schematic diagram of the direction of vehicle speed when a tire of a wheel has a wheel angle provided by the third embodiment of the present invention;

[0022] Figure 4 is a schematic diagram of a longitudinal vehicle speed calculated using a different method provided in the fourth embodiment of the present invention;

[0023] Figure 5 This is a schematic diagram of a change based on wheel speed provided by the fifth embodiment of the present invention;

[0024] Figure 6 Schematic diagram of a longitudinal measured vehicle speed calculated based on wheel speed and an actual measured vehicle speed provided by a sixth embodiment of the present invention;

[0025] Figure 7 This is a schematic diagram of a mapping relationship between fluctuation magnitude and quality factor provided by the seventh embodiment of the present invention;

[0026] Figure 8 Schematic diagram of a longitudinal vehicle speed and a measured vehicle speed calculated based on a longitudinal vehicle speed estimation method provided by an eighth embodiment of the present invention;

[0027] Figure 9 1 is a schematic structural diagram of a longitudinal vehicle speed estimation device provided by a ninth embodiment of the present invention;

[0028] Figure 10 It is a structural diagram of a computer device provided in the tenth embodiment of the present invention. DETAILED DESCRIPTION

[0029] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0030] It should be understood that when used in the present specification and the appended claims, the term "comprising" indicates the presence of described features, integers, steps, operations, elements and / or components, but does not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or groups thereof.

[0031] It will also be understood that the term "and / or" used in the present description and appended claims refers to and includes any and all possible combinations of one or more of the associated listed items.

[0032] As used in the present specification and the appended claims, the term "if" may be interpreted as "when" or "upon" or "in response to determining" or "in response to detecting," depending on the context. Similarly, the phrase "if it is determined" or "if [described condition or event] is detected" may be interpreted as meaning "upon determination" or "in response to determining" or "upon detection of [described condition or event]" or "in response to detecting [described condition or event]," depending on the context.

[0033] In addition, in the description of the present specification and the appended claims, the terms "first", "second", "third", etc. are only used to distinguish the descriptions and cannot be understood as indicating or implying relative importance.

[0034] References to "one embodiment" or "some embodiments" in the present specification mean that a particular feature, structure, or characteristic described in conjunction with that embodiment is included in one or more embodiments of the present invention. Thus, phrases such as "in one embodiment," "in some embodiments," "in other embodiments," and "in yet other embodiments" appearing in various places in this specification do not necessarily refer to the same embodiment, but rather mean "one or more, but not all, embodiments," unless otherwise specifically emphasized. The terms "including," "comprising," "having," and variations thereof mean "including but not limited to," unless otherwise specifically emphasized.

[0035] It should be understood that the order of execution of the steps in the following embodiments does not necessarily mean the order in which they are executed. The order in which each process is executed should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0036] In order to illustrate the technical solution of the present invention, specific embodiments are provided below.

[0037] See also Figure 1 , is a flow chart of a longitudinal vehicle speed estimation method provided by the first embodiment of the present invention, such as Figure 1 As shown, the longitudinal vehicle speed estimation method may include the following steps.

[0038] S101: The real-time wheel speed collected in the current cycle and the historical lateral estimated vehicle speed and historical longitudinal estimated vehicle speed obtained by the vehicle speed observation model in the previous cycle are input into the tire model to obtain the estimated longitudinal resultant force and the estimated lateral resultant force of the current cycle.

[0039] In step S101, the tire model is used to estimate the estimated longitudinal force and the estimated lateral force of the current cycle, wherein the input of the tire model includes the real-time wheel speed collected in the current cycle and the historical lateral estimated vehicle speed and historical longitudinal estimated vehicle speed obtained by the vehicle speed observation model in the previous cycle.

[0040] In this embodiment, a tire model is obtained, wherein the tire model includes a tire longitudinal force estimation module and a tire lateral force estimation module. The tire longitudinal force estimation module is used to estimate the longitudinal resultant force, and the tire lateral force estimation module is used to estimate the lateral resultant force. The input of the tire longitudinal force estimation module is the real-time wheel speed collected in the current cycle and the historical longitudinal estimated vehicle speed obtained from the vehicle speed observation model in the previous cycle. The output of the tire longitudinal force estimation module is the estimated longitudinal resultant force. The input of the tire lateral force estimation module is the real-time wheel speed collected in the current cycle and the historical lateral estimated vehicle speed obtained from the vehicle speed observation model in the previous cycle. The output of the tire lateral force estimation module is the estimated lateral resultant force.

[0041] It should be noted that when using the tire model to calculate the estimated longitudinal and lateral forces for the current cycle, it is necessary to calculate the estimated longitudinal and lateral forces for each tire. Specifically, the estimated longitudinal forces for each tire are summed to obtain the estimated longitudinal force, and the estimated lateral forces for each tire are summed to obtain the estimated lateral force. In other words, the input to the tire longitudinal force estimation module is the real-time wheel speed collected for each tire in the current cycle and the historical estimated longitudinal vehicle speed for the corresponding tire. The input to the tire lateral force estimation module is the real-time wheel speed collected for each tire in the current cycle and the historical estimated lateral vehicle speed for the corresponding tire.

[0042] When calculating the estimated longitudinal force of each tire, the wheel speed of each tire and the historical longitudinal estimated vehicle speed of the corresponding tire need to be input into the tire longitudinal force estimation module. Among them, the historical lateral estimated vehicle speed and the historical longitudinal estimated vehicle speed are the speeds at the center of mass of the vehicle. Therefore, the historical lateral estimated vehicle speed and the historical longitudinal estimated vehicle speed need to be converted into the historical longitudinal estimated vehicle speed and the historical lateral estimated vehicle speed at each tire.

[0043] See also Figure 2 , is a tire position structure diagram of a vehicle provided by the second embodiment of the present invention, such as Figure 2 As shown in the figure, a is the distance from the center of mass of the vehicle to the front tire, b is the distance from the center of mass of the vehicle to the rear tire, T is the horizontal distance between the left and right tires, is the historical longitudinal estimated speed, i.e. the historical longitudinal estimated speed at the vehicle’s center of mass, is the historical lateral estimated speed, i.e. the historical lateral estimated speed at the vehicle’s center of mass, The yaw angular velocity collected in the current cycle.

[0044] The conversion formula for converting the estimated vehicle speed at the vehicle's center of mass to the estimated vehicle speed at each tire is as follows:

[0045]

[0046]

[0047]

[0048]

[0049]

[0050]

[0051]

[0052]

[0053] in, is the estimated longitudinal speed at the left front tire after conversion, is the estimated longitudinal speed at the right front wheel tire after conversion, is the estimated longitudinal speed at the left rear tire after conversion, is the estimated longitudinal speed at the right rear tire after conversion, is the historical lateral estimated vehicle speed at the left front wheel tire after conversion, is the historical lateral estimated vehicle speed at the right front wheel tire after conversion, is the historical lateral estimated vehicle speed at the left rear tire after conversion, is the historical lateral estimated vehicle speed at the right rear tire after conversion, is the historical longitudinal estimated speed, i.e. the historical longitudinal estimated speed at the vehicle’s center of mass, is the historical lateral estimated speed, i.e. the historical lateral estimated speed at the vehicle’s center of mass, is the yaw rate collected in the current cycle, T is the horizontal distance between the left and right tires, a is the distance from the vehicle's center of mass to the front tire, and b is the distance from the vehicle's center of mass to the rear tire.

[0054] The historical estimated longitudinal and lateral speeds at each tire are calculated using the conversion formula. The estimated longitudinal and lateral forces for each tire are calculated based on the historical estimated longitudinal and lateral speeds at each tire and the real-time wheel speeds collected during the current cycle.

[0055] Optionally, the longitudinal vehicle speed estimation method further includes:

[0056] Obtaining the wheel angle collected in the current cycle, converting the historical lateral estimated vehicle speed and the historical longitudinal estimated vehicle speed according to the wheel angle to obtain the converted historical lateral estimated vehicle speed and the converted historical longitudinal estimated vehicle speed;

[0057] The real-time wheel speed, the historical lateral estimated vehicle speed, and the converted historical longitudinal estimated vehicle speed are input into the tire model to obtain the estimated longitudinal resultant force and the estimated lateral resultant force of the current cycle.

[0058] In this embodiment, when using the tire model to calculate the estimated longitudinal and lateral forces for the current cycle, it is necessary to calculate the estimated longitudinal and lateral forces for each tire. Specifically, the estimated longitudinal forces for each tire are summed to obtain the estimated longitudinal force, and the estimated lateral forces for each tire are summed to obtain the estimated lateral force. Specifically, the inputs to the tire longitudinal force estimation module are the real-time wheel speed collected for each tire in the current cycle and the historical estimated longitudinal vehicle speed for the corresponding tire. The inputs to the tire lateral force estimation module are the real-time wheel speed collected for each tire in the current cycle and the historical estimated lateral vehicle speed for the corresponding tire.

[0059] When calculating the estimated longitudinal force of each tire, the wheel speed of each tire and the historical longitudinal estimated vehicle speed of the corresponding tire need to be input into the tire longitudinal force estimation module. Among them, the historical lateral estimated vehicle speed and the historical longitudinal estimated vehicle speed are the speeds at the center of mass of the vehicle. Therefore, the historical lateral estimated vehicle speed and the historical longitudinal estimated vehicle speed need to be converted into the historical longitudinal estimated vehicle speed and the historical lateral estimated vehicle speed at each tire.

[0060] It should be noted that, when each wheel has a wheel angle, the estimated longitudinal vehicle speed and the estimated lateral vehicle speed at each tire need to be converted to the vehicle speed in a coordinate system where the corresponding wheel angle is 0.

[0061] See also Figure 3 , is a schematic diagram of the direction of vehicle speed when a tire of a wheel has a wheel angle provided by the third embodiment of the present invention, wherein, is the estimated longitudinal speed, is the estimated lateral speed, is the wheel angle, is the estimated longitudinal speed when the wheel angle is 0, The estimated lateral speed when the wheel angle is 0.

[0062] In this embodiment, when each wheel has a wheel angle, the longitudinal estimated vehicle speed and the lateral estimated vehicle speed at each tire are converted to the vehicle speed in the coordinate system where the corresponding wheel angle is 0. The conversion formula is as follows:

[0063]

[0064]

[0065] in, is the estimated longitudinal speed of the i-th tire after conversion, is the lateral estimated vehicle speed at the i-th tire after conversion, is the wheel angle corresponding to the i-th tire.

[0066] The converted longitudinal estimated vehicle speed at the tire and the converted lateral estimated vehicle speed at the tire are used to replace the above-mentioned longitudinal estimated vehicle speed and lateral estimated vehicle speed at the corresponding tire, and are input into the tire longitudinal force estimation module and the tire lateral force estimation module.

[0067] S102: Input the yaw rate and vehicle acceleration collected in the current cycle, the historical lateral estimated vehicle speed and the historical longitudinal estimated vehicle speed, and the estimated longitudinal resultant force and the estimated lateral resultant force in the current cycle into a vehicle speed observation model to obtain the real-time longitudinal estimated vehicle speed in the current cycle.

[0068] In step S102, the vehicle speed observation model is used to estimate the real-time longitudinal estimated vehicle speed of the current cycle, wherein the input of the vehicle speed observation model includes the yaw angular velocity and vehicle acceleration collected in the current cycle, the historical lateral estimated vehicle speed and the historical longitudinal estimated vehicle speed, and the estimated longitudinal resultant force and the estimated lateral resultant force of the current cycle, and the real-time longitudinal estimated vehicle speed of the current cycle is output.

[0069] In this embodiment, a vehicle speed observation model is constructed, wherein the vehicle speed observation model includes a corresponding adjustment module, a correction module and a calculation module. The input of the adjustment module includes the estimated longitudinal resultant force and the estimated lateral resultant force of the current cycle, as well as the vehicle acceleration. The estimated longitudinal resultant force and the estimated lateral resultant force are used as preset values ​​of the adjustment module, and the longitudinal resultant force and the lateral resultant force calculated based on the vehicle acceleration are used as actual values. The output acceleration is adjusted according to the preset value and the actual value, so that the longitudinal resultant force and the lateral resultant force calculated based on the output acceleration are closer to the estimated longitudinal resultant force and the estimated lateral resultant force.

[0070] The correction module is used to correct the vehicle acceleration output by the adjustment module according to the yaw angular velocity, thereby avoiding the influence of the yaw angular velocity on the acceleration and improving the accuracy of the output vehicle acceleration. The calculation module is used to calculate the real-time longitudinal estimated vehicle speed of the current cycle according to the corrected longitudinal vehicle acceleration.

[0071] In this embodiment, a tire model is introduced, and a vehicle speed observation model is constructed based on it, so as to suppress the "drift" problem when integrating the acceleration signal.

[0072] Optionally, the yaw rate and vehicle acceleration collected in the current cycle, the historical lateral estimated vehicle speed and the historical longitudinal estimated vehicle speed, and the estimated longitudinal resultant force and the estimated lateral resultant force in the current cycle are input into the vehicle speed observation model to obtain the real-time longitudinal estimated vehicle speed in the current cycle, including:

[0073] Obtain the vehicle mass and calculate the actual longitudinal force and actual lateral force of the vehicle based on the vehicle mass and the vehicle acceleration collected in the current cycle;

[0074] According to the actual longitudinal resultant force and the actual lateral resultant force, as well as the estimated longitudinal resultant force and the estimated lateral resultant force, the vehicle acceleration is adjusted by the adjustment module to obtain an adjusted vehicle acceleration;

[0075] According to the yaw angular velocity, the adjusted vehicle acceleration is corrected by a correction module to obtain a corrected longitudinal vehicle acceleration;

[0076] Based on the historical longitudinal estimated vehicle speed and the corrected longitudinal vehicle acceleration, the real-time longitudinal estimated vehicle speed of the current cycle is calculated through the calculation module.

[0077] In this embodiment, the vehicle speed observation model includes a regulation module, a correction module, and a calculation module. The regulation module includes a PI regulator for adjusting the output vehicle acceleration. It should be noted that the regulation module includes a first regulation module and a second regulation module. The first regulation module includes a first PI regulator, and the second regulation module includes a second PI regulator. The first regulation module is used to adjust the output longitudinal vehicle acceleration, while the second regulation module is used to adjust the output lateral vehicle acceleration.

[0078] It should be noted that the vehicle acceleration collected during the current cycle includes longitudinal and lateral accelerations. The direction of the longitudinal acceleration is the same as the direction of the estimated longitudinal vehicle speed, and the direction of the lateral acceleration is the same as the direction of the estimated lateral vehicle speed. The first adjustment module receives as input the estimated longitudinal resultant force, the longitudinal acceleration, and the vehicle mass. The longitudinal acceleration and the vehicle mass are used to calculate the actual longitudinal resultant force of the vehicle. This is calculated by multiplying the longitudinal acceleration by the vehicle mass to obtain the actual longitudinal resultant force. The first regulator adjusts the resultant force so that the actual longitudinal resultant force, obtained by multiplying the longitudinal acceleration by the vehicle mass, approximates the estimated longitudinal resultant force.

[0079] The inputs of the second adjustment module are the estimated lateral resultant force, the lateral vehicle acceleration and the vehicle mass. The lateral vehicle acceleration and the vehicle mass are used to calculate the actual lateral resultant force of the vehicle, that is, the actual lateral resultant force is obtained by multiplying the lateral vehicle acceleration and the vehicle mass. The second regulator is used to adjust the actual lateral resultant force obtained by multiplying the output adjusted lateral vehicle acceleration and the vehicle mass so that the actual lateral resultant force is close to the estimated lateral resultant force.

[0080] The correction module is used to correct the adjusted longitudinal vehicle acceleration, wherein the correction formula is as follows:

[0081]

[0082] in, is the corrected longitudinal vehicle acceleration, is the adjusted longitudinal vehicle acceleration, is the yaw angular velocity, is the historical lateral estimated vehicle speed. Used to correct the longitudinal vehicle acceleration when the vehicle is in yaw motion.

[0083] In another embodiment, the correction module further includes a first correction module and a second correction module, wherein the first correction module is used to correct the adjusted longitudinal vehicle acceleration, and the second correction module is used to correct the adjusted lateral vehicle acceleration, wherein the correction formula is as follows:

[0084]

[0085]

[0086]

[0087] in, is the corrected longitudinal vehicle acceleration, is the adjusted longitudinal vehicle acceleration, is the yaw angular velocity, is the estimated lateral vehicle speed of the current cycle, is the historical lateral estimated vehicle speed of the previous cycle, is the corrected lateral vehicle acceleration, t is the time of the current cycle, is the adjusted lateral vehicle acceleration, The historical longitudinal estimated vehicle speed for the previous cycle.

[0088] It should be noted that the first correction module is used to correct the adjusted longitudinal vehicle acceleration to obtain a corrected longitudinal vehicle acceleration, and the second correction module is used to correct the adjusted lateral vehicle acceleration to obtain a corrected lateral vehicle acceleration. When the first correction module corrects the adjusted longitudinal vehicle acceleration, it does so based on the lateral vehicle speed, that is, based on the estimated lateral vehicle speed for the current cycle. Therefore, the estimated lateral vehicle speed for the current cycle needs to be calculated, and the estimated lateral vehicle speed for the current cycle is calculated based on the corrected lateral vehicle acceleration.

[0089] In this embodiment, when correcting the acceleration, it is not necessary to rely on the longitudinal vehicle speed measurement value based on the wheel speed, and the influence of the yaw motion on the relationship between the velocity change rate and the acceleration is taken into account, thereby improving the accuracy of the acceleration correction.

[0090] It should be noted that the lateral estimated vehicle speed of the current cycle may also be calculated using other methods, such as a calculation method using a single-track vehicle model, which is not limited in this embodiment.

[0091] Based on the historical longitudinal estimated vehicle speed and the corrected longitudinal vehicle acceleration, the calculation module calculates the real-time longitudinal estimated vehicle speed for the current cycle. When calculating the real-time longitudinal estimated vehicle speed for the current cycle, the corrected longitudinal vehicle acceleration can be integrated according to the time of the current cycle to obtain the change in the historical longitudinal estimated vehicle speed. Then, based on the historical longitudinal estimated vehicle speed and the change in the historical longitudinal estimated vehicle speed, the real-time longitudinal estimated vehicle speed for the current cycle is obtained. The calculation formula is as follows:

[0092]

[0093] in, is the real-time longitudinal estimated vehicle speed for the current cycle, is the historical longitudinal estimation car of the previous cycle, is the corrected longitudinal vehicle acceleration, and t is the time of the current cycle.

[0094] See also Figure 4 , is a schematic diagram of a longitudinal vehicle speed calculated using a different method provided in the fourth embodiment of the present invention, Figure 4 The figure includes the longitudinal speed obtained through actual measurement, the longitudinal speed calculated by direct integration of the longitudinal acceleration, and the longitudinal speed calculated based on the speed observation model. The horizontal axis represents time, and the vertical axis represents the longitudinal speed. The green curve represents the longitudinal speed obtained through actual measurement, the blue curve represents the longitudinal speed calculated by direct integration of the longitudinal acceleration, and the red curve represents the longitudinal speed calculated based on the speed observation model. The figure shows that the longitudinal speed calculated based on the speed observation model is similar to the measured longitudinal speed, but the longitudinal speed calculated based on the speed observation model is more accurate.

[0095] In this embodiment, a tire model is referenced and used as a basis to construct a vehicle speed observation model. The mechanical equilibrium equation and the relationship between speed and acceleration are used to construct a vehicle speed observer. Compared with the direct integration of the longitudinal acceleration, this can effectively suppress the integral "drift" problem caused by the "zero drift" error.

[0096] S103: Inputting the historical wheel speeds and the real-time wheel speeds collected in the previous cycle into a vehicle speed measurement model to obtain the real-time longitudinal measured vehicle speed of the current cycle, performing weighted fusion on the real-time longitudinal estimated vehicle speed and the real-time longitudinal measured vehicle speed to obtain the actual longitudinal vehicle speed of the current cycle.

[0097] In step S103, the real-time longitudinal measured vehicle speed of the current cycle is calculated based on the wheel speed. The wheel speed includes the historical wheel speed and the real-time wheel speed collected in the current cycle. The real-time longitudinal estimated vehicle speed and the real-time longitudinal measured vehicle speed are weightedly fused to obtain the actual longitudinal vehicle speed of the current cycle. That is, the longitudinal vehicle speeds calculated by different methods are fused to obtain the actual longitudinal vehicle speed of the current cycle.

[0098] In this embodiment, the historical wheel speeds collected in the previous cycle and the real-time wheel speeds collected in the current cycle are input into the vehicle speed measurement model to obtain the real-time longitudinal measured vehicle speed of the current cycle. After the historical wheel speeds collected in the previous cycle and the real-time wheel speeds collected in the current cycle are input into the vehicle speed measurement model, the wheel speed quality factor of each wheel is calculated based on the historical wheel speeds and the real-time wheel speeds collected in the current cycle, and the real-time longitudinal measured vehicle speed of the current cycle is calculated based on the wheel speed quality factors and the real-time wheel speeds.

[0099] It should be noted that, see Figure 5, is a schematic diagram of a change based on wheel speed provided by the fifth embodiment of the present invention. In the figure, the horizontal axis is time and the vertical axis is wheel speed. The figure includes the left front wheel speed of the left front wheel and the right front wheel speed of the right front wheel, the left rear wheel speed of the left rear wheel, and the right rear wheel speed of the right rear wheel. See Figure 6 , is a schematic diagram of a longitudinal measured vehicle speed and an actual measured vehicle speed calculated based on wheel speed according to the sixth embodiment of the present invention. Figure 5 and Figure 6 It can be seen that when the wheel speed fluctuates significantly, such as the wheel speed within 80s-100s, the real-time longitudinal measured vehicle speed within the corresponding time will also fluctuate significantly, thus affecting the accuracy.

[0100] Therefore, a weighted fusion is performed on the real-time longitudinal estimated speed and the real-time longitudinal measured speed to obtain the actual longitudinal speed of the current cycle. When weighted fusion is performed on the real-time longitudinal estimated speed and the real-time longitudinal measured speed, different weights are assigned to the real-time longitudinal estimated speed and the real-time longitudinal measured speed, and the fusion is performed based on the different weights.

[0101] Optionally, the historical wheel speeds and real-time wheel speeds collected in the previous cycle are input into the vehicle speed measurement model to obtain the real-time longitudinal vehicle speed of the current cycle, including:

[0102] Calculate the wheel speed quality factor based on the historical wheel speed and the real-time wheel speed;

[0103] The real-time longitudinal measured vehicle speed of the current cycle is calculated based on the wheel speed quality factor and the real-time wheel speed.

[0104] In this embodiment, the wheel speed quality factor is calculated based on the historical wheel speed and the real-time wheel speed, wherein the wheel speed quality factor is used to characterize the fluctuation of the wheel speed in adjacent cycles, and the wheel speed quality factor is determined based on the fluctuation of the wheel speed in adjacent cycles.

[0105] It should be noted that, since the fluctuation of the wheel speed of each wheel may be different, the wheel speed quality factor of the corresponding wheel is calculated based on the wheel speed of each wheel in adjacent cycles.

[0106] It should be noted that the calculation of wheel speed fluctuations between adjacent cycles can be performed based on the wheel speed acceleration. When calculating the wheel speed acceleration, the time derivative of the wheel speeds between adjacent cycles is taken to obtain the wheel speed acceleration. The wheel speed acceleration is used as the wheel speed fluctuation magnitude, and the wheel speed quality factor is determined based on the wheel speed fluctuation magnitudes between adjacent cycles. A mapping relationship exists between the wheel speed fluctuation magnitude and the wheel speed quality factor. Therefore, based on this mapping relationship and the wheel speed acceleration, the wheel speed quality factor for the current cycle can be determined.

[0107] See also Figure 7, is a schematic diagram of a mapping relationship between fluctuation size and quality factor provided by Example 7 of the present invention, wherein the horizontal axis is the fluctuation size and the vertical axis is the quality factor. The quality factor initially remains unchanged as the fluctuation size increases, then, as the fluctuation size increases, the quality factor becomes smaller and smaller, and finally, as the fluctuation size increases, the quality factor remains unchanged. That is, when the fluctuation size is small, that is, when the acceleration of the wheel speed is small, that is, when the wheel speed change is small, it is considered that the wheel speed maintains a relatively stable state. The greater the reliability of the longitudinal vehicle speed calculated based on the wheel speed, the greater the corresponding wheel speed quality factor. As the fluctuation size increases, that is, the more unstable the wheel speed is, the lower the reliability of the longitudinal vehicle speed calculated based on the wheel speed, and the lower the corresponding quality factor. When the fluctuation size reaches a certain value, it is considered that the reliability of the longitudinal vehicle speed calculated based on the wheel speed is 0, and the corresponding quality factor is 0.

[0108] In another embodiment, when calculating the fluctuation magnitude of wheel speed between adjacent cycles, the calculation can also be performed based on the wheel speed jerk. When calculating the wheel speed jerk, the time derivative of the wheel speed acceleration between adjacent cycles is taken to obtain the wheel speed jerk. The wheel speed jerk is used as the fluctuation magnitude of the wheel speed, and a wheel speed quality factor is determined based on the fluctuation magnitude of the wheel speed between adjacent cycles. A mapping relationship exists between the wheel speed fluctuation magnitude and the wheel speed quality factor. Therefore, based on this mapping relationship and the wheel speed jerk, the wheel speed quality factor for the current cycle can be determined.

[0109] In another embodiment, when calculating the fluctuation size of the wheel speed in adjacent cycles, the calculation can also be performed based on the wheel speed acceleration and the wheel speed jerk, and the minimum value of the wheel speed acceleration and the wheel speed jerk is used as the fluctuation size. According to the corresponding fluctuation size, the corresponding wheel speed quality factor is determined.

[0110] The real-time longitudinal speed of the vehicle in the current cycle is calculated based on the wheel speed quality factor and the real-time wheel speed. The formula for calculating the real-time longitudinal speed is as follows:

[0111]

[0112] in, is the real-time longitudinal speed measurement of the current cycle, is the wheel speed of the i-th wheel converted to the longitudinal speed at the vehicle's center of mass, is the weighting coefficient of the corresponding wheel.

[0113] The formula for converting the wheel speed of each wheel to the longitudinal speed at the vehicle's center of mass is as follows:

[0114]

[0115]

[0116]

[0117]

[0118] in, The real-time wheel speed based on the left front wheel in the current cycle Converted to the longitudinal speed at the vehicle's center of mass, The real-time wheel speed based on the right front wheel in the current cycle Converted to the longitudinal speed at the vehicle's center of mass, The real-time wheel speed based on the left rear wheel in the current cycle Converted to the longitudinal speed at the vehicle's center of mass, The real-time wheel speed based on the right rear wheel in the current cycle Converted to the longitudinal speed at the vehicle's center of mass, is the wheel radius, is the yaw rate collected in the current cycle, and T is the horizontal distance between the left and right tires.

[0119] in, is the weighting coefficient of the i-th wheel. When determining the weighting coefficient, it is determined according to the wheel speed quality factor of the corresponding wheel. There is a mapping relationship between the wheel speed quality factor and the weighting coefficient. The larger the wheel speed quality factor, the larger the corresponding weighting coefficient.

[0120] Optionally, after inputting the historical wheel speeds and the real-time wheel speeds collected in the previous cycle into the vehicle speed measurement model to obtain the real-time longitudinal vehicle speed of the current cycle, the following steps are further included:

[0121] Based on the quality factor, the credibility of the reliability of the real-time longitudinal speed measurement is calculated.

[0122] In this embodiment, the reliability of the real-time longitudinal speed measurement is calculated based on the wheel speed quality factor corresponding to each wheel. The calculation formula of the reliability is as follows:

[0123]

[0124] in, For credibility, is the wheel speed quality factor corresponding to the i-th wheel.

[0125] In this embodiment, the wheel speed quality factor of each wheel is added together to obtain the corresponding credibility, that is, the stability of the wheel speed of each wheel is taken into consideration, thereby improving the calculation accuracy of the credibility.

[0126] Optionally, performing weighted fusion on the real-time longitudinal estimated vehicle speed and the real-time longitudinal measured vehicle speed to obtain the actual longitudinal vehicle speed of the current cycle includes:

[0127] Determining a first weight value of the real-time longitudinal estimated vehicle speed and a second weight value of the real-time longitudinal measurement according to the credibility;

[0128] The real-time longitudinal estimated vehicle speed and the real-time longitudinal measured vehicle speed are weightedly fused according to the first weight value and the second weight value to obtain the actual longitudinal vehicle speed of the current cycle.

[0129] In this embodiment, a first weight value of the real-time longitudinal estimated vehicle speed and a second weight value of the real-time longitudinal measurement are determined based on the credibility, wherein the first weight value and the second weight value are weight values ​​calculated based on the Carr filter.

[0130] It should be noted that in Kalman filtering, the state quantity is set to , set the observation quantity to ,in, is the first-order derivative of the longitudinal vehicle speed in the current cycle, is the longitudinal speed of the vehicle in the current cycle, then in the Kalman filter, the state equation and observation equation can be written as:

[0131]

[0132]

[0133] in, is the second-order derivative of the longitudinal vehicle speed in the current cycle, is the first-order derivative of the longitudinal vehicle speed in the current cycle, is the longitudinal vehicle speed in the current cycle.

[0134] After discretization, the state equation is obtained:

[0135]

[0136] The observation equation is:

[0137]

[0138] in, , , is the state quantity of the Kth period, is the state quantity of the K-1th period, is the observation value of the Kth period.

[0139] Based on the state equation and observation equation, a Kalman filter is constructed, where the prediction link of the kth cycle is:

[0140]

[0141]

[0142] The update steps are:

[0143]

[0144]

[0145]

[0146] in, is the real-time longitudinal estimated vehicle speed in the Kth cycle, The real-time longitudinal estimated vehicle speed in the K-1th cycle, is the observation noise covariance, Determined by the credibility, the smaller the credibility, the larger the observation noise covariance, and the larger the credibility, the smaller the observation noise covariance. It is the external uncertainty, which is determined by the tire model and can be a fixed value or the same as the wheel speed reliability. Related, is the state uncertainty, and and Related. is the Kalman gain of the Kth period. is the state variable of the Kth cycle, which is related to the real-time longitudinal estimated vehicle speed calculated based on the tire model. is the observed value of the Kth period, which is related to the real-time longitudinal measured vehicle speed calculated based on the wheel speed.

[0147] Based on the Kalman gain obtained in the Kth period, the first weight value of the real-time longitudinal estimated vehicle speed and the second weight value of the real-time longitudinal measurement in the Kth period are determined. Based on the first weight value and the second weight value, the real-time longitudinal estimated vehicle speed and the real-time longitudinal measurement vehicle speed are weightedly fused. The weighted fusion formula is as follows.

[0148]

[0149] in, is the actual longitudinal speed of the previous cycle after fusion, is the real-time longitudinal estimated vehicle speed for the current cycle, is the real-time longitudinal speed measurement of the current cycle, is the Kalman gain of the current cycle. is the first weight value, The weight calculation is automatically completed by the Kalman filter, which has a filtering effect and avoids the jump of the longitudinal vehicle speed estimation result.

[0150] See also Figure 8 , a schematic diagram illustrating the longitudinal vehicle speed calculated based on a longitudinal vehicle speed estimation method and the measured vehicle speed, provided in Example 8 of the present invention. The horizontal axis in the figure represents time, and the vertical axis represents the longitudinal vehicle speed. The figure shows that the longitudinal vehicle speed calculated based on the longitudinal vehicle speed estimation method is close to the measured vehicle speed, indicating that the longitudinal vehicle speed calculated based on the longitudinal vehicle speed estimation method has a high degree of accuracy.

[0151] Optionally, calculating a first weight value of the real-time longitudinal estimated vehicle speed and a second weight value of the real-time longitudinal measurement according to the credibility includes:

[0152] Determine the observation error of the real-time longitudinal speed measurement based on the credibility;

[0153] A first weighted value of the real-time longitudinal estimated vehicle speed and a second weighted value of the real-time longitudinal measured vehicle speed are calculated based on the observation error.

[0154] In this embodiment, an observation error of the real-time longitudinal speed measurement is determined based on the reliability. The observation error corresponding to the reliability can be determined by looking up a table. Lower reliability indicates greater observation error, and higher reliability indicates lower observation error. Based on the observation error, a first weight value for the real-time longitudinal estimated speed and a second weight value for the real-time longitudinal measured speed are calculated. Specifically, a Kalman gain is calculated based on the observation error, and the first weight value for the real-time longitudinal estimated speed and the second weight value for the real-time longitudinal measured speed are determined based on the Kalman gain.

[0155] The real-time wheel speed collected in the current cycle and the historical lateral estimated speed and historical longitudinal estimated speed obtained by the speed observation model in the previous cycle are input into the tire model to obtain the estimated longitudinal resultant force and estimated lateral resultant force of the current cycle, the yaw angular velocity and vehicle acceleration collected in the current cycle, the historical lateral estimated speed and historical longitudinal estimated speed, and the estimated longitudinal resultant force and estimated lateral resultant force of the current cycle are input into the speed observation model to obtain the real-time longitudinal estimated speed of the current cycle, the historical wheel speed and real-time wheel speed collected in the previous cycle are input into the speed measurement model to obtain the real-time longitudinal measured speed of the current cycle, the real-time longitudinal estimated speed and the real-time longitudinal measured speed are weightedly fused to obtain the actual longitudinal speed of the current cycle. In this application, the real-time longitudinal estimated speed is fused with the speed measurement value based on the wheel speed to improve the accuracy of the longitudinal speed estimation and the applicability of different working conditions, provide accurate longitudinal speed input for the vehicle control system, and improve the control effect.

[0156] See also Figure 9 , is a schematic diagram of the structure of a longitudinal vehicle speed estimation device provided by the ninth embodiment of the present invention. For the sake of convenience, only the parts related to the embodiment of the present invention are shown. Figure 9The longitudinal vehicle speed estimation device 90 includes: a first obtaining module 91 , a second obtaining module 92 , and a fusion module 93 .

[0157] The first obtaining module 91 is used to input the real-time wheel speed collected in the current cycle and the historical lateral estimated vehicle speed and historical longitudinal estimated vehicle speed obtained by the vehicle speed observation model in the previous cycle into the tire model to obtain the estimated longitudinal resultant force and estimated lateral resultant force of the current cycle.

[0158] The second obtaining module 92 is used to input the yaw angular velocity and vehicle acceleration collected in the current cycle, the historical lateral estimated vehicle speed and the historical longitudinal estimated vehicle speed, and the estimated longitudinal resultant force and the estimated lateral resultant force of the current cycle into the vehicle speed observation model to obtain the real-time longitudinal estimated vehicle speed of the current cycle.

[0159] Fusion module 93 is used to input the historical wheel speed collected in the previous cycle and the real-time wheel speed collected in the current cycle into the vehicle speed measurement model to obtain the real-time longitudinal measured vehicle speed of the current cycle, and perform weighted fusion on the real-time longitudinal estimated vehicle speed and the real-time longitudinal measured vehicle speed to obtain the actual longitudinal vehicle speed of the current cycle.

[0160] Optionally, the longitudinal vehicle speed estimation device 90 further includes:

[0161] The conversion module is used to obtain the wheel angle collected in the current cycle, and convert the historical lateral estimated vehicle speed and the historical longitudinal estimated vehicle speed according to the wheel angle to obtain the converted historical lateral estimated vehicle speed and the converted historical longitudinal estimated vehicle speed.

[0162] The module is used to input the real-time wheel speed, the historical lateral estimated vehicle speed and the converted historical longitudinal estimated vehicle speed into the tire model to obtain the estimated longitudinal force and the estimated lateral force of the current cycle.

[0163] Optionally, the second obtaining module 92 includes:

[0164] The first calculation unit is used to obtain the vehicle mass and calculate the actual longitudinal force and the actual lateral force based on the vehicle mass and the vehicle acceleration collected in the current cycle.

[0165] The regulating unit is used to regulate the vehicle acceleration through the regulating module according to the actual longitudinal resultant force and the actual lateral resultant force, as well as the estimated longitudinal resultant force and the estimated lateral resultant force, to obtain the regulated vehicle acceleration.

[0166] The correction unit is used to correct the adjusted vehicle acceleration through the correction module according to the yaw angular velocity to obtain a corrected longitudinal vehicle acceleration.

[0167] The second calculation unit is used to calculate the real-time longitudinal estimated vehicle speed of the current cycle through the calculation module according to the historical longitudinal estimated vehicle speed and the corrected longitudinal vehicle acceleration.

[0168] Optionally, the fusion module 93 includes:

[0169] The third calculation unit is used to calculate the wheel speed quality factor according to the historical wheel speed and the real-time wheel speed.

[0170] The fourth calculation unit is used to calculate the real-time longitudinal measured vehicle speed of the current cycle according to the wheel speed quality factor and the real-time wheel speed.

[0171] Optionally, the fusion module 93 further includes:

[0172] The fifth calculation unit is configured to calculate, based on the quality factor, a credibility factor representing the reliability of the real-time longitudinal vehicle speed measurement.

[0173] Optionally, the fusion module 93 further includes:

[0174] a determining unit, configured to determine a first weight value of the real-time longitudinal estimated vehicle speed and a second weight value of the real-time longitudinal measured vehicle speed according to the credibility;

[0175] The fusion unit is used to perform weighted fusion on the real-time longitudinal estimated vehicle speed and the real-time longitudinal measured vehicle speed according to the first weight value and the second weight value to obtain the actual longitudinal vehicle speed of the current cycle.

[0176] Optionally, the determining unit includes:

[0177] The determination subunit is used to determine the observation error of the real-time longitudinal measurement of the vehicle speed according to the credibility.

[0178] The calculation subunit is used to calculate a first weight value of the real-time longitudinal estimated vehicle speed and a second weight value of the real-time longitudinal measured vehicle speed according to the observation error.

[0179] It should be noted that the information interaction, execution process and other contents between the above modules are based on the same concept as the embodiment of the method of the present invention. Their specific functions and technical effects can be found in the method embodiment part and will not be repeated here.

[0180] Figure 10 This is a schematic diagram of the structure of a computer device provided by the eighth embodiment of the present invention. Figure 10 As shown, the computer device of this embodiment includes: at least one processor ( Figure 10 Only one is shown), a memory, and a computer program stored in the memory and executable on at least one processor, wherein when the processor executes the computer program, the steps of any of the above-mentioned embodiments of the method for estimating longitudinal vehicle speed are implemented.

[0181] The computer device may include, but is not limited to, a processor and a memory. It will be understood by those skilled in the art that Figure 10 This is merely an example of a computer device and does not constitute a limitation on the computer device. The computer device may include more or fewer components than shown in the figure, or a combination of certain components, or different components, for example, it may also include a network interface, etc.

[0182] The processor may be a CPU, other general-purpose processors, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor.

[0183] Memory includes readable storage media, internal memory, and the like. Internal memory can be the internal memory of a computer device, providing an environment for the operation of the operating system and computer-readable instructions stored in the readable storage medium. The readable storage medium can be the computer device's hard drive. In other embodiments, it can also be an external storage device, such as a plug-in hard drive, a Smart Media Card (SMC), a Secure Digital (SD) card, or a flash memory card. Furthermore, memory can include both the computer device's internal storage unit and external storage devices. Memory is used to store the operating system, application programs, boot loaders, data, and other programs, such as the program code of computer programs. Memory can also be used to temporarily store data that has been output or is about to be output.

[0184] Those skilled in the art can clearly understand that, for the convenience and simplicity of description, only the division of the above-mentioned functional units and modules is used as an example for illustration. In actual applications, the above-mentioned functions can be distributed and completed by different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiment can be integrated into a processing unit, or each unit can exist physically alone, or two or more units can be integrated into one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of a software functional unit. In addition, the specific names of the functional units and modules are only for the convenience of distinguishing each other and are not used to limit the scope of protection of the present invention. The specific working process of the units and modules in the above-mentioned device can refer to the corresponding process in the aforementioned method embodiment, which will not be repeated here. If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the present invention can implement all or part of the process steps in the above-mentioned method embodiments by instructing the relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium. When executed by a processor, the computer program can implement the steps of the above-mentioned method embodiments. The computer program includes computer program code, which can be in source code form, object code form, executable file, or some intermediate form. Computer-readable media can include at least: any entity or device capable of carrying computer program code, recording media, computer memory, read-only memory (ROM), random access memory (RAM), electric carrier signals, telecommunications signals, and software distribution media. Examples include USB flash drives, removable hard drives, magnetic disks, or optical disks. In some jurisdictions, based on legislation and patent practice, computer-readable media cannot be electric carrier signals or telecommunications signals.

[0185] The present invention may implement all or part of the processes in the above-mentioned method embodiments, and may also be completed through a computer program product. When the computer program product runs on a computer device, the computer device can implement the steps in the above-mentioned method embodiments when executing the computer program product.

[0186] In the above embodiments, the description of each embodiment has its own focus. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant description of other embodiments.

[0187] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professionals and technicians can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of the present invention.

[0188] In the embodiments provided by the present invention, it should be understood that the disclosed apparatus / computer equipment and methods can be implemented in other ways. For example, the apparatus / computer equipment embodiments described above are merely illustrative. For example, the division of modules or units is merely a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, 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.

[0189] Units described as separate components may or may not be physically separate, and components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected to achieve the purpose of this embodiment according to actual needs.

[0190] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention, and should all be included in the scope of protection of the present invention.

Claims

1. A method for estimating longitudinal vehicle speed, characterized in that: include: The real-time wheel speed collected in the current cycle and the historical lateral and longitudinal estimated speeds obtained by the speed observation model in the previous cycle are input into the tire model to obtain the estimated longitudinal and lateral force of the current cycle; Inputting the yaw rate and vehicle acceleration collected in the current cycle, the historical lateral estimated vehicle speed and historical longitudinal estimated vehicle speed, and the estimated longitudinal resultant force and estimated lateral resultant force in the current cycle into the vehicle speed observation model to obtain the real-time longitudinal estimated vehicle speed in the current cycle; The historical wheel speed collected in the previous cycle and the real-time wheel speed are input into the vehicle speed measurement model to obtain the real-time longitudinal measured vehicle speed of the current cycle, and the real-time longitudinal estimated vehicle speed and the real-time longitudinal measured vehicle speed are weightedly fused to obtain the actual longitudinal vehicle speed of the current cycle.

2. The longitudinal vehicle speed estimation method according to claim 1, wherein: The longitudinal vehicle speed estimation method further includes: Obtaining the wheel angle collected in the current cycle, and converting the historical lateral estimated vehicle speed and the historical longitudinal estimated vehicle speed according to the wheel angle to obtain a converted historical lateral estimated vehicle speed and a converted historical longitudinal estimated vehicle speed; The real-time wheel speed, the historical lateral estimated vehicle speed, and the converted historical longitudinal estimated vehicle speed are input into the tire model to obtain the estimated longitudinal resultant force and the estimated lateral resultant force of the current cycle.

3. The longitudinal vehicle speed estimation method according to claim 1, wherein: The vehicle speed observation model includes an adjustment module, a correction module and a calculation module; The step of inputting the yaw rate and vehicle acceleration collected during the current period, the historical estimated lateral vehicle speed and the historical estimated longitudinal vehicle speed, and the estimated longitudinal resultant force and the estimated lateral resultant force during the current period into the vehicle speed observation model to obtain the real-time estimated longitudinal vehicle speed during the current period includes: Obtaining the vehicle mass, and calculating the actual longitudinal resultant force and the actual lateral resultant force based on the vehicle mass and the vehicle acceleration collected in the current cycle; According to the actual longitudinal resultant force and the actual lateral resultant force, and the estimated longitudinal resultant force and the estimated lateral resultant force, the vehicle acceleration is adjusted by an adjustment module to obtain an adjusted vehicle acceleration; Correcting the adjusted vehicle acceleration by a correction module according to the yaw angular velocity to obtain a corrected longitudinal vehicle acceleration; The real-time longitudinal estimated vehicle speed of the current cycle is calculated by a calculation module based on the historical longitudinal estimated vehicle speed and the corrected longitudinal vehicle acceleration.

4. The longitudinal vehicle speed estimation method according to claim 1, wherein: The step of inputting the historical wheel speeds collected in the previous cycle and the real-time wheel speeds into the vehicle speed measurement model to obtain the real-time longitudinal vehicle speed of the current cycle includes: Calculating a wheel speed quality factor according to the historical wheel speed and the real-time wheel speed; The real-time longitudinal measured vehicle speed of the current cycle is calculated based on the wheel speed quality factor and the real-time wheel speed.

5. The longitudinal vehicle speed estimation method according to claim 4, characterized in that: After inputting the historical wheel speeds collected in the previous cycle and the real-time wheel speeds into the vehicle speed measurement model to obtain the real-time longitudinal vehicle speed of the current cycle, the method further includes: A credibility factor representing the reliability of the real-time longitudinal vehicle speed measurement is calculated based on the wheel speed quality factor.

6. The longitudinal vehicle speed estimation method according to claim 5, characterized in that: The weighted fusion of the real-time longitudinal estimated vehicle speed and the real-time longitudinal measured vehicle speed to obtain the actual longitudinal vehicle speed of the current cycle includes: determining a first weight value for the real-time longitudinal estimated vehicle speed and a second weight value for the real-time longitudinal measured vehicle speed based on the credibility; The real-time longitudinal estimated vehicle speed and the real-time longitudinal measured vehicle speed are weightedly fused according to the first weight value and the second weight value to obtain the actual longitudinal vehicle speed of the current cycle.

7. The longitudinal vehicle speed estimation method according to claim 6, wherein: Determining a first weight value of the real-time longitudinal estimated vehicle speed and a second weight value of the real-time longitudinal measured vehicle speed based on the credibility includes: determining an observation error of the real-time longitudinally measured vehicle speed based on the reliability; A first weighted value of the real-time longitudinal estimated vehicle speed and a second weighted value of the real-time longitudinal measured vehicle speed are calculated based on the observation error.

8. A longitudinal vehicle speed estimation device, characterized in that: include: The first obtaining module is used to input the real-time wheel speed collected in the current cycle and the historical lateral estimated vehicle speed and historical longitudinal estimated vehicle speed obtained by the vehicle speed observation model in the previous cycle into the tire model to obtain the estimated longitudinal force and estimated lateral force of the current cycle; a second obtaining module, configured to input the yaw angular velocity and vehicle acceleration collected in the current cycle, the historical lateral estimated vehicle speed and the historical longitudinal estimated vehicle speed, and the estimated longitudinal resultant force and the estimated lateral resultant force in the current cycle into the vehicle speed observation model to obtain the real-time longitudinal estimated vehicle speed in the current cycle; A fusion module is used to input the historical wheel speed collected in the previous cycle and the real-time wheel speed into a vehicle speed measurement model to obtain the real-time longitudinal measured vehicle speed of the current cycle, and to perform weighted fusion on the real-time longitudinal estimated vehicle speed and the real-time longitudinal measured vehicle speed to obtain the actual longitudinal vehicle speed of the current cycle.

9. A computer device, characterized in that: The computer device includes a processor, a memory, and a computer program stored in the memory and executable on the processor. The computer device is configured to execute the longitudinal vehicle speed estimation method according to any one of claims 1 to 7.

10. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the method for estimating the longitudinal vehicle speed according to any one of claims 1 to 7 is implemented.

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