Longitudinal vehicle speed estimation method, device, equipment and medium

Abstract

The invention relates to the technical field of vehicle driving control, in particular to a longitudinal vehicle speed estimation method, device and equipment and a medium. Inputting the yaw velocity and the vehicle acceleration collected in the current period, the estimated longitudinal resultant force and the estimated lateral resultant force into a vehicle speed observation model to obtain the real-time longitudinal estimated vehicle speed of the current period, and inputting the historical wheel speed and the real-time wheel speed collected in the previous period into a vehicle speed measurement model to obtain the real-time longitudinal estimated vehicle speed of the current period. And carrying out weighted fusion on the real-time longitudinal estimation vehicle speed and the real-time longitudinal measurement vehicle speed to obtain the actual longitudinal vehicle speed of the current period. According to the method, the real-time longitudinal estimated vehicle speed and the vehicle speed measurement value based on the wheel speed are fused, the accuracy of longitudinal vehicle speed estimation and the applicability to different working conditions are improved, accurate longitudinal vehicle speed input is provided for a vehicle control system, and the control effect is improved.

Description

Technical Field

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

[0002] The longitudinal speed estimation of a vehicle is the basis for the estimation and control of the vehicle's driving state. For example, the slip rate calculation, the estimation of the sideslip angle of the center of mass, the anti-lock control, the drive anti-skid control and the stability control all require the longitudinal speed information. The measurement of the longitudinal speed cannot be obtained through a simple sensor like the wheel speed or acceleration. If direct measurement is required, the required sensor is generally very expensive and cannot be widely used in automobiles. At the same time, as the basic vehicle state quantity, many vehicle characteristics are related to the longitudinal speed. Therefore, there are high requirements for the real-time and accuracy of the longitudinal speed estimation. Accurate longitudinal speed estimation results are conducive to further calculation of the driving state of other vehicles and to improving the control effect of the control system.

[0003] According to the sensors currently installed on automobiles, the 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. However, when the wheel slips or locks obviously, or the wheel speed fluctuates significantly due to the road surface or steering, it is difficult to obtain the 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 longitudinal speed estimation process.

[0006] A first aspect of an embodiment of the present application provides a method for estimating a longitudinal vehicle speed, comprising: The real-time wheel speed collected in the current cycle and the historical lateral estimated vehicle speed and the 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; Inputting 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 of the current cycle into the vehicle speed observation model to obtain the real-time longitudinal estimated vehicle speed of 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.

[0007] A second aspect of an embodiment of the present application provides a longitudinal vehicle speed estimation device, comprising: 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 the 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; A second obtaining module 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; The fusion module is used to input the historical wheel speed collected in the previous cycle and the real-time wheel speed into the 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.

[0008] 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.

[0009] 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 method for estimating the longitudinal vehicle speed described in any one of the first aspects is implemented.

[0010] Compared with the prior art, the present invention has the following beneficial effects: 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 the estimated lateral resultant force of the current cycle, the yaw rate and vehicle acceleration collected in the current cycle, the historical lateral estimated speed and the historical longitudinal estimated speed, and the estimated longitudinal resultant force and the 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 collected in the previous cycle and the real-time wheel speed are input into the speed measurement model to obtain the real-time longitudinal measured speed of the current cycle, and 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

[0011] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative labor.

[0012] Figure 1 is a flow chart of a method for estimating longitudinal vehicle speed provided in Embodiment 1 of the present invention; Figure 2 This is a tire position structure diagram of a vehicle provided by Embodiment 2 of the present invention; Figure 3 It is a schematic diagram of the direction of vehicle speed when a tire of a wheel has a wheel turning angle provided by the third embodiment of the present invention; Figure 4 is a schematic diagram of a longitudinal vehicle speed calculated by a different method provided in a fourth embodiment of the present invention; Figure 5 This is a schematic diagram of a change based on wheel speed provided by Embodiment 5 of the present invention; Figure 6 is a 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; Figure 7 is a schematic diagram of a mapping relationship between fluctuation size and quality factor provided in Embodiment 7 of the present invention; Figure 8 It is a schematic diagram of calculating the longitudinal vehicle speed and the measured vehicle speed based on the longitudinal vehicle speed estimation method provided by the eighth embodiment of the present invention; Fig. 9is a schematic structural diagram of a longitudinal vehicle speed estimation device provided by Embodiment 9 of the present invention; Fig.10 It is a structural diagram of a computer device provided in Embodiment 10 of the present invention. DETAILED DESCRIPTION

[0013] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0014] 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 exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or combinations thereof.

[0015] It should also be understood that the term "and / or" used in the present description and the appended claims refers to and includes any and all possible combinations of one or more of the associated listed items.

[0016] 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.

[0017] 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.

[0018] References to "one embodiment" or "some embodiments" etc. described in the present specification mean that one or more embodiments of the present invention include specific features, structures or characteristics described in conjunction with the embodiment. Therefore, the statements "in one embodiment", "in some embodiments", "in some other embodiments", "in some other embodiments", etc. that appear in different places in this specification do not necessarily refer to the same embodiment, but mean "one or more but not all embodiments", unless otherwise specifically emphasized in other ways. The terms "including", "comprising", "having" and their variations all mean "including but not limited to", unless otherwise specifically emphasized in other ways.

[0019] It should be understood that the order of execution of the steps in the following embodiments does not imply a precedence of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0020] In order to illustrate the technical solution of the present invention, specific embodiments are provided below for illustration.

[0021] See also Figure 1 , is a flow chart of a method for estimating longitudinal vehicle speed provided by Embodiment 1 of the present invention, such as Figure 1 As shown, the longitudinal vehicle speed estimation method may include the following steps.

[0022] S101: The real-time wheel speed collected in the current cycle and the historical lateral estimated vehicle speed and the 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.

[0023] 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.

[0024] 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, wherein 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 through 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 through the vehicle speed observation model in the previous cycle, and the output of the tire lateral force estimation module is the estimated lateral resultant force.

[0025] It should be noted that when using the tire model to calculate the estimated longitudinal force and the estimated lateral force of the current cycle, it is necessary to calculate the estimated longitudinal force and the estimated lateral force of each tire, that is, to add the estimated longitudinal force of each tire to obtain the estimated longitudinal force, and to add the estimated lateral force of each tire to obtain the estimated lateral force. That is, the input of the tire longitudinal force estimation module is the real-time wheel speed collected in the current cycle of each tire and the historical longitudinal estimated vehicle speed of the corresponding tire, and the input of the tire lateral force estimation module is the real-time wheel speed collected in the current cycle of each tire and the historical lateral estimated vehicle speed of the corresponding tire.

[0026] When calculating the estimated longitudinal force of each tire, it is necessary to input the wheel speed of each tire and the historical longitudinal estimated vehicle speed of the corresponding tire into the tire longitudinal force estimation module, wherein the historical lateral estimated vehicle speed and the historical longitudinal estimated vehicle speed are the vehicle speeds at the center of mass of the vehicle. Therefore, it is necessary to convert the historical lateral estimated vehicle speed and the historical longitudinal estimated vehicle speed into the historical longitudinal estimated vehicle speed and the historical lateral estimated vehicle speed at each tire.

[0027] See also Figure 2 , is a tire position structure diagram of a vehicle provided in Embodiment 2 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, that is, the historical longitudinal estimated speed at the vehicle's center of mass, is the historical lateral estimated vehicle speed, i.e., the historical lateral estimated vehicle speed at the vehicle’s center of mass, The yaw rate collected in the current cycle.

[0028] 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: in, is the estimated longitudinal speed at the left front tire after conversion, is the estimated longitudinal speed at the right front 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 tire after conversion, is the historical lateral estimated vehicle speed at the right front 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, that is, the historical longitudinal estimated speed at the vehicle's center of mass, is the historical lateral estimated vehicle speed, i.e., the historical lateral estimated vehicle 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 center of mass of the vehicle to the front tire, and b is the distance from the center of mass of the vehicle to the rear tire.

[0029] According to the conversion formula, the historical estimated longitudinal speed and the historical estimated lateral speed at each tire are calculated. According to the historical estimated longitudinal speed and the historical estimated lateral speed at each tire, and the real-time wheel speed collected in the current cycle, the estimated longitudinal force and the estimated lateral force of the corresponding tire are calculated.

[0030] Optionally, the longitudinal vehicle speed estimation method further includes: Obtaining the wheel steering angle collected in the current cycle, converting the historical lateral estimated vehicle speed and the historical longitudinal estimated vehicle speed according to the wheel steering angle, and obtaining the converted historical lateral estimated vehicle speed and the 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.

[0031] In this embodiment, when the estimated longitudinal force and the estimated lateral force of the current cycle are calculated using the tire model, the estimated longitudinal force and the estimated lateral force of each tire need to be calculated, that is, the estimated longitudinal force of each tire is added to obtain the estimated longitudinal force, and the estimated lateral force of each tire is added to obtain the estimated lateral force. That is, the input of the tire longitudinal force estimation module is the real-time wheel speed collected in the current cycle of each tire and the historical longitudinal estimated vehicle speed of the corresponding tire, and the input of the tire lateral force estimation module is the real-time wheel speed collected in the current cycle of each tire and the historical lateral estimated vehicle speed of the corresponding tire.

[0032] When calculating the estimated longitudinal force of each tire, it is necessary to input the wheel speed of each tire and the historical longitudinal estimated vehicle speed of the corresponding tire into the tire longitudinal force estimation module, wherein the historical lateral estimated vehicle speed and the historical longitudinal estimated vehicle speed are the vehicle speeds at the center of mass of the vehicle. Therefore, it is necessary to convert the historical lateral estimated vehicle speed and the historical longitudinal estimated vehicle speed into the historical longitudinal estimated vehicle speed and the historical lateral estimated vehicle speed at each tire.

[0033] It should be noted that, when the tire of each wheel has a wheel angle, the longitudinal estimated vehicle speed and the lateral estimated vehicle speed at each tire need to be converted into the vehicle speed in the coordinate system where the corresponding wheel angle is 0.

[0034] See also Figure 3 , is a schematic diagram of the direction of vehicle speed when a tire of a wheel has a wheel turning 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, is the estimated lateral vehicle speed when the wheel angle is 0.

[0035] 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: 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.

[0036] 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.

[0037] 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 of the current cycle into the vehicle speed observation model to obtain the real-time longitudinal estimated vehicle speed of the current cycle.

[0038] 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.

[0039] 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, and the vehicle acceleration, the estimated longitudinal resultant force and the estimated lateral resultant force are used as preset values ​​of the adjustment module, the longitudinal resultant force and the lateral resultant force calculated based on the vehicle acceleration are used as actual values, and 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 according to the output acceleration are closer to the estimated longitudinal resultant force and the estimated lateral resultant force.

[0040] The correction module is used to correct the vehicle acceleration output by the adjustment module according to the yaw angular velocity, avoid the influence of the yaw angular velocity on the acceleration, and improve 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.

[0041] In this embodiment, a tire model is introduced, and a vehicle speed observation model is constructed based on the tire model, so as to suppress the "drift" problem when integrating the acceleration signal.

[0042] 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 of the current cycle are input into the vehicle speed observation model to obtain the real-time longitudinal estimated vehicle speed of the current cycle, including: 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; 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; According to the yaw angular velocity, the adjusted vehicle acceleration is corrected by a correction module to obtain a corrected longitudinal vehicle acceleration; According to 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.

[0043] In this embodiment, the vehicle speed observation model includes an adjustment module, a correction module and a calculation module, and the adjustment module includes a PI regulator for adjusting the output vehicle acceleration. It should be noted that the adjustment module includes a first adjustment module and a second adjustment module, the first adjustment module includes a first PI regulator, and the second adjustment module includes a second PI regulator. The first adjustment module is used to adjust the output longitudinal vehicle acceleration, and the second adjustment module is used to adjust the output lateral vehicle acceleration.

[0044] It should be noted that the vehicle acceleration collected in the current cycle includes the longitudinal vehicle acceleration and the lateral vehicle acceleration, wherein the direction of the longitudinal vehicle acceleration is the same as the direction of the longitudinal estimated vehicle speed, and the direction of the lateral vehicle acceleration is the same as the direction of the lateral estimated vehicle speed. The input of the first adjustment module is the estimated longitudinal resultant force, the longitudinal vehicle acceleration and the vehicle mass, wherein the longitudinal vehicle acceleration and the vehicle mass are used to calculate the actual longitudinal resultant force of the vehicle, that is, the longitudinal vehicle acceleration is multiplied by the vehicle mass to obtain the actual longitudinal resultant force, and the first regulator is used to adjust so that the actual longitudinal resultant force obtained by multiplying the output adjusted longitudinal vehicle acceleration and the vehicle mass is close to the estimated longitudinal resultant force.

[0045] The input of the second adjustment module is the estimated lateral resultant force, the lateral vehicle acceleration and the vehicle mass, wherein the lateral vehicle acceleration and the vehicle mass are used to calculate the actual lateral resultant force of the vehicle, that is, the lateral vehicle acceleration is multiplied by the vehicle mass to obtain the actual lateral resultant force, which is adjusted by the second regulator so that the actual lateral resultant force obtained by multiplying the output adjusted lateral vehicle acceleration by the vehicle mass is close to the estimated lateral resultant force. The correction module is used to correct the adjusted longitudinal vehicle acceleration, wherein the correction formula is as follows: 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.

[0046] In another embodiment, the correction module further includes a first correction module and a second correction module, 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: in, is the corrected longitudinal vehicle acceleration, is the adjusted longitudinal vehicle acceleration, is the yaw angular velocity, is the estimated lateral vehicle speed in the current cycle, is the historical lateral estimated vehicle speed in 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.

[0047] It should be noted that the first correction module is used to correct the adjusted longitudinal vehicle acceleration to obtain the corrected longitudinal vehicle acceleration, and the second correction module is used to correct the adjusted lateral vehicle acceleration to obtain the corrected lateral vehicle acceleration. When the first correction module corrects the adjusted longitudinal vehicle acceleration, it corrects based on the lateral vehicle speed, that is, based on the lateral estimated vehicle speed of the current cycle. Therefore, it is necessary to calculate the lateral estimated vehicle speed of the current cycle, and the lateral estimated vehicle speed of the current cycle is calculated according to the corrected lateral vehicle acceleration.

[0048] In this embodiment, when the acceleration is corrected, 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 considered, thereby improving the accuracy of the acceleration correction.

[0049] 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 of a single-track vehicle model, which is not limited in this embodiment.

[0050] According to 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. When calculating the real-time longitudinal estimated vehicle speed of 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, and then the real-time longitudinal estimated vehicle speed of the current cycle is obtained according to the historical longitudinal estimated vehicle speed and the change in the historical longitudinal estimated vehicle speed. The calculation formula is as follows: in, is the real-time longitudinal estimated vehicle speed of the current cycle, is the historical longitudinal estimation vehicle of the previous cycle, is the corrected longitudinal vehicle acceleration, and t is the time of the current cycle.

[0051] See also Figure 4 , is a schematic diagram of a longitudinal vehicle speed calculated by a different method provided in the fourth embodiment of the present invention, Figure 4In the figure, the longitudinal vehicle speed obtained by actual measurement, the longitudinal vehicle speed calculated by direct integration of the longitudinal vehicle acceleration, and the longitudinal vehicle speed calculated based on the vehicle speed observation model are included. The horizontal axis is time, the vertical axis is the longitudinal vehicle speed, the green curve is the longitudinal vehicle speed obtained by actual measurement, the blue curve is the longitudinal vehicle speed calculated by direct integration of the longitudinal vehicle acceleration, and the red curve is the longitudinal vehicle speed calculated based on the vehicle speed observation model. It can be seen from the figure that the longitudinal vehicle speed calculated based on the vehicle speed observation model is similar to the longitudinal vehicle speed obtained by actual measurement, and the longitudinal vehicle speed calculated based on the vehicle speed observation model has higher accuracy.

[0052] In this embodiment, a tire model is referenced and a vehicle speed observation model is constructed based on it. A vehicle speed observer is constructed using the mechanical equilibrium equation and the relationship between speed and acceleration. Compared with the direct integration of the longitudinal acceleration, the integral "drift" problem caused by the "zero drift" error can be effectively suppressed.

[0053] S103: 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 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.

[0054] 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, 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, that is, the longitudinal vehicle speeds calculated by different methods are fused to obtain the actual longitudinal vehicle speed of the current cycle.

[0055] 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 according to 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 according to the wheel speed quality factor and the real-time wheel speed.

[0056] It should be noted that see Figure 5 , is a schematic diagram of a change based on wheel speed provided by Embodiment 5 of the present invention, in which 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 provided in Embodiment 6 of the present invention, according to Figure 5and 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 in the corresponding time will also fluctuate significantly, thus affecting the accuracy.

[0057] Therefore, 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. When the real-time longitudinal estimated speed and the real-time longitudinal measured speed are weightedly fused, different weight values ​​are set for the real-time longitudinal estimated speed and the real-time longitudinal measured speed, and the addition and fusion are performed according to different weight values.

[0058] Optionally, the historical wheel speed and the real-time wheel speed collected in the previous cycle are input into the vehicle speed measurement model to obtain the real-time longitudinal measured vehicle speed of the current cycle, including: Calculate the 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.

[0059] 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 size of the wheel speed in adjacent cycles, and the wheel speed quality factor is determined based on the fluctuation size of the wheel speed in adjacent cycles.

[0060] It should be noted that, since the fluctuation magnitude of the wheel speed of each wheel may be different, the wheel speed quality factor of the corresponding wheel is calculated according to the wheel speed of each wheel in adjacent cycles.

[0061] It should be noted that when calculating the fluctuation magnitude of wheel speeds in adjacent cycles, the calculation can be performed based on the acceleration of the wheel speeds, wherein when calculating the acceleration of the wheel speeds, the time derivative of the wheel speeds in adjacent cycles is performed to obtain the acceleration of the wheel speeds. The acceleration of the wheel speeds is used as the fluctuation magnitude of the wheel speeds, and the wheel speed quality factor is determined based on the fluctuation magnitude of the wheel speeds in adjacent cycles, wherein there is a mapping relationship between the fluctuation magnitude of the wheel speeds and the wheel speed quality factor, therefore, based on the corresponding mapping relationship and the acceleration of the wheel speeds, the wheel speed quality factor of the current cycle can be determined.

[0062] See also Figure 7, is a schematic diagram of a mapping relationship between a fluctuation size and a quality factor provided in Embodiment 7 of the present invention, wherein the horizontal axis is the fluctuation size, and the vertical axis is the quality factor. As the fluctuation size increases, the quality factor initially remains unchanged, and then, as the fluctuation size increases, the quality factor becomes smaller and smaller. 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 changes slightly, 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.

[0063] In another embodiment, when calculating the fluctuation magnitude of wheel speeds in adjacent cycles, the calculation can also be performed based on the jerk of the wheel speed, wherein when calculating the jerk of the wheel speed, the acceleration of the wheel speeds in adjacent cycles is time-derived to obtain the jerk of the wheel speed. The jerk of the wheel speed is used as the fluctuation magnitude of the wheel speed, and the wheel speed quality factor is determined based on the fluctuation magnitude of the wheel speeds in adjacent cycles, wherein there is a mapping relationship between the fluctuation magnitude of the wheel speed and the wheel speed quality factor, therefore, based on the corresponding mapping relationship and the jerk of the wheel speed, the wheel speed quality factor of the current cycle can be determined.

[0064] In another embodiment, when calculating the fluctuation size of the wheel speed in adjacent cycles, the calculation can also be performed based on the acceleration of the wheel speed and the wheel speed jerk, and the minimum value of the wheel speed acceleration and the wheel speed jerk is taken as the fluctuation size, and the corresponding wheel speed quality factor is determined based on the corresponding fluctuation size.

[0065] According to the wheel speed quality factor and the real-time wheel speed, the real-time longitudinal measured vehicle speed of the current cycle is calculated. The formula for calculating the real-time longitudinal measured vehicle speed is as follows: in, is the real-time longitudinal measured vehicle speed for the current cycle, is the wheel speed of the ith wheel converted to the longitudinal speed at the vehicle's center of mass, is the weighting coefficient of the corresponding wheel.

[0066] The formula for calculating the wheel speed of each wheel converted to the longitudinal speed at the center of mass of the vehicle is as follows: 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.

[0067] in, is the weighting coefficient of the ith 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.

[0068] Optionally, after inputting the historical wheel speed and the real-time wheel speed collected in the previous cycle into the vehicle speed measurement model to obtain the real-time longitudinal measured vehicle speed of the current cycle, the method further includes: Based on the quality factor, the credibility that characterizes the reliability of the real-time longitudinal speed measurement is calculated.

[0069] In this embodiment, the credibility of the reliability of the real-time longitudinal speed measurement is calculated according to the wheel speed quality factor corresponding to each wheel, wherein the credibility calculation formula is as follows: in, For credibility, is the wheel speed quality factor corresponding to the i-th wheel.

[0070] In this embodiment, the wheel speed quality factor of each wheel is added 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.

[0071] Optionally, weighted fusion is performed 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, including: 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; 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.

[0072] 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 according to the credibility, wherein the first weight value and the second weight value are weight values ​​calculated according to the Carr filter.

[0073] It should be noted that in Kalman filtering, the state quantity is set to , and set the observation to ,in, is the first-order derivative of the longitudinal vehicle speed in the current cycle, is the longitudinal speed of the current cycle, then in Kalman filtering, the state equation and observation equation can be written as: 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.

[0074] After discretization, the state equation is obtained: The observation equation is: in, , , is the state quantity of the Kth period, is the state quantity of the K-1th period, is the observed value of the Kth period.

[0075] Based on the state equation and observation equation, a Kalman filter is constructed, in which the prediction link of the kth cycle is: The update links are: 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 equal to the wheel speed reliability. Related, is the state uncertainty, and and Related. is the Kalman gain of the Kth period. is the state quantity 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.

[0076] According to 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. According to the first weight value and the second weight value, the real-time longitudinal estimated vehicle speed and the real-time longitudinal measured vehicle speed are weightedly fused. The weighted fusion formula is as follows.

[0077] in, is the actual longitudinal speed of the previous cycle after fusion, is the real-time longitudinal estimated vehicle speed of the current cycle, is the real-time longitudinal measured vehicle speed for 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 to avoid the jump of the longitudinal vehicle speed estimation result.

[0078] See also Figure 8 , is a schematic diagram of a longitudinal vehicle speed and a measured vehicle speed calculated based on a longitudinal vehicle speed estimation method provided by Embodiment 8 of the present invention. In the figure, the horizontal axis represents time, and the vertical axis represents the longitudinal vehicle speed. From the figure, it can be concluded that the longitudinal vehicle speed calculated based on the longitudinal vehicle speed estimation method is close to the measured vehicle speed, that is, the longitudinal vehicle speed calculated based on the longitudinal vehicle speed estimation method has a higher accuracy. 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: According to the credibility, the observation error of the real-time longitudinal speed measurement is determined; 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.

[0079] In this embodiment, the observation error of the real-time longitudinal measurement of the vehicle speed is determined according to the credibility, wherein the observation error corresponding to the credibility can be determined by looking up a table, the smaller the credibility, the larger the observation error, and the larger the credibility, the smaller the observation error. According to the observation error, the first weight value of the real-time longitudinal estimation of the vehicle speed and the second weight value of the real-time longitudinal measurement of the vehicle speed are calculated, that is, the Kalman gain is calculated according to the observation error, and the first weight value of the real-time longitudinal estimation of the vehicle speed and the second weight value of the real-time longitudinal measurement of the vehicle speed are determined according to the Kalman gain.

[0080] 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 the estimated lateral resultant force of the current cycle, the yaw rate and vehicle acceleration collected in the current cycle, the historical lateral estimated speed and the historical longitudinal estimated speed, and the estimated longitudinal resultant force and the 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 collected in the previous cycle and the real-time wheel speed are input into the speed measurement model to obtain the real-time longitudinal measured speed of the current cycle, and 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.

[0081] See also Fig. 9 , is a schematic diagram of the structure of a longitudinal vehicle speed estimation device provided by Embodiment 9 of the present invention. For the sake of convenience, only the parts related to the embodiment of the present invention are shown. Fig. 9 The longitudinal vehicle speed estimation device 90 includes: a first obtaining module 91 , a second obtaining module 92 , and a fusion module 93 .

[0082] 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 force and estimated lateral force of the current cycle.

[0083] 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.

[0084] The 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 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.

[0085] Optionally, the longitudinal vehicle speed estimation device 90 further includes: 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.

[0086] 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 resultant force and the estimated lateral resultant force of the current cycle.

[0087] Optionally, the second obtaining module 92 includes: The first calculation unit is used to obtain the vehicle mass, and calculate the actual longitudinal force and the actual lateral force according to the vehicle mass and the vehicle acceleration collected in the current cycle.

[0088] 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, so as to obtain the regulated vehicle acceleration.

[0089] 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.

[0090] 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.

[0091] Optionally, the fusion module 93 includes: 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.

[0092] 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.

[0093] Optionally, the fusion module 93 further includes: The fifth calculation unit is used to calculate the credibility of the reliability of the real-time longitudinal measurement of the vehicle speed according to the quality factor.

[0094] Optionally, the fusion module 93 further includes: A determination 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; 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.

[0095] Optionally, the determining unit includes: The determination subunit is used to determine the observation error of the real-time longitudinal measurement of the vehicle speed according to the credibility.

[0096] 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.

[0097] 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.

[0098] Fig.10 Schematic diagram of the structure of a computer device provided by Embodiment 8 of the present invention. Fig.10 As shown, the computer device of this embodiment includes: at least one processor ( Fig.10 Only one is shown in the figure), 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 in any of the above-mentioned embodiments of the method for estimating longitudinal vehicle speed are implemented. The computer device may include, but is not limited to, a processor and a memory. Those skilled in the art will appreciate that Fig.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 those shown in the figure, or a combination of certain components, or different components, for example, it may also include a network interface, etc.

[0099] The processor may be a CPU, or other general-purpose processors, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA) or 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, etc.

[0100] The memory includes a readable storage medium, an internal memory, etc., wherein the internal memory may be the memory of a computer device, and the internal memory provides an environment for the operation of the operating system and computer-readable instructions in the readable storage medium. The readable storage medium may be a hard disk of a computer device, and in other embodiments, it may also be an external storage device of the computer device, for example, a plug-in hard disk, a smart memory card (Smart Media Card, SMC), a secure digital (Secure Digital, SD) card, a flash card (Flash Card), etc. equipped on the computer device. Further, the memory may also include both an internal storage unit of the computer device and an external storage device. The memory is used to store an operating system, an application program, a boot loader (BootLoader), data, and other programs, such as the program code of a computer program, etc. The memory may also be used to temporarily store data that has been output or is to be output.

[0101] The technicians in the relevant field 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. In practical applications, the above-mentioned function allocation can be completed by different functional units and modules as needed, that is, the internal structure of the device is 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 separately, 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 software functional units. 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 above-mentioned 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 such understanding, the present invention implements all or part of the processes in the above-mentioned embodiment method, which can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a computer-readable storage medium. When the computer program is executed by the processor, the steps of the above-mentioned method embodiment can be implemented. Among them, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form. The computer-readable medium may at least include: any entity or device capable of carrying computer program code, recording medium, computer memory, read-only memory (ROM), random access memory (RAM), electric carrier signal, telecommunication signal and software distribution medium. For example, a USB flash drive, a mobile hard disk, a magnetic disk or an optical disk. In some jurisdictions, according to legislation and patent practice, computer-readable media cannot be electric carrier signals and telecommunication signals.

[0102] The present invention implements all or part of the processes in the above-mentioned embodiment method, and can also be completed by 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 embodiment when executing.

[0103] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0104] 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. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.

[0105] In the embodiments provided by the present invention, it should be understood that the disclosed devices / computer equipment and methods can be implemented in other ways. For example, the device / computer equipment embodiments described above are only schematic, for example, the division of modules or units is only a logical function division, and there may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another 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.

[0106] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0107] 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 the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention, and should be included in the protection scope 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 estimated vehicle speed and the 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; Inputting 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 of the current cycle into the vehicle speed observation model to obtain the real-time longitudinal estimated vehicle speed of 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, characterized in that: The longitudinal vehicle speed estimation method further includes: Acquire the wheel angle collected in the current period, and convert 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, characterized in that: 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 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 includes: Obtaining the vehicle mass, and calculating the actual longitudinal force and the actual lateral force according to 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; According to the yaw angular velocity, the adjusted vehicle acceleration is corrected by a correction module to obtain a corrected longitudinal vehicle acceleration; The real-time longitudinal estimated vehicle speed of the current cycle is calculated by a calculation module according to the historical longitudinal estimated vehicle speed and the corrected longitudinal vehicle acceleration.

4. The longitudinal vehicle speed estimation method according to claim 1, characterized in that: The step of inputting the historical wheel speed collected in the previous cycle and the real-time wheel speed into the vehicle speed measurement model to obtain the real-time longitudinal measured vehicle speed in 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 speed collected in the previous cycle and the real-time wheel speed into the vehicle speed measurement model to obtain the real-time longitudinal measured vehicle speed of the current cycle, the method further includes: The credibility characterizing the reliability of the real-time longitudinal measurement of the vehicle speed is calculated based on the quality factor.

6. The method for estimating longitudinal vehicle speed according to claim 5, characterized in that: The step of 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: 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 according to 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 method for estimating longitudinal vehicle speed according to claim 6, characterized in that: The step of calculating the first weight value of the real-time longitudinal estimated vehicle speed and the second weight value of the real-time longitudinal measured vehicle speed according to the credibility comprises: Determining an observation error of the real-time longitudinally measured vehicle speed based on the credibility; 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 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 the 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; A second obtaining module 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; The fusion module is used to input the historical wheel speed collected in the previous cycle and the real-time wheel speed into the 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 comprises a processor, a memory, and a computer program stored in the memory and executable on the processor, and the computer device is used 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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