Vehicle center of mass identification method, vehicle-mounted electronic device, vehicle, and storage medium

Abstract

The application relates to a vehicle center of mass identification method, a vehicle-mounted electronic device, a vehicle and a storage medium. An acceleration value and a free radius of a target tire are obtained, and a first ground leaving angle of the target tire is calculated based on the acceleration value and the free radius; the first ground leaving angle is the maximum included angle between the ground area of the tire and the vertical direction when the tire is lifted from the ground; a performance parameter of the target tire is obtained, and the free radius, the first ground leaving angle and the performance parameter are substituted into a flexible ring model to calculate the load of the target tire; the flexible ring model contains contribution values of various performance parameters to the load distribution of the tire, and the performance parameters include tire internal air pressure and tire stiffness; the wheelbase and the width of the vehicle are obtained, and the center of mass position of the vehicle is calculated according to the load of the target tire, the wheelbase and the width of the vehicle; the vehicle center of mass is realized in real time and accurately fed back, and the problem that the vehicle center of mass identification is not accurate enough in the related art is solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of vehicle engineering, and in particular to a vehicle centroid identification method, a vehicle-mounted electronic device, a vehicle, and a storage medium. BACKGROUND

[0002] With the rapid development of intelligent driving and autonomous driving technologies, the stability and safety of vehicles have become increasingly important. The position of the vehicle centroid is one of the key factors that affect the control stability and safety of the vehicle during driving. If accurate and real-time vehicle execution positions cannot be provided during vehicle control, the tracking error of the vehicle will become larger.

[0003] Traditional vehicle centroid identification methods usually rely on static measurement or estimation methods based on engine and motor torque output. However, these methods often have large errors in actual application, which can lead to inaccurate vehicle control and potential safety hazards.

[0004] At present, there is no effective solution to the problem of inaccurate vehicle centroid identification in the related art. SUMMARY

[0005] Therefore, it is necessary to provide a high-precision vehicle centroid identification method, a vehicle-mounted electronic device, a vehicle, and a storage medium to solve the above technical problems.

[0006] In a first aspect, the present application provides a vehicle centroid identification method. The method comprises:

[0007] obtaining an acceleration value and a free radius of a target tire, and calculating a first ground departure angle of the target tire based on the acceleration value and the free radius; wherein the first ground departure angle is the maximum angle between the ground contact area of the tire and the vertical direction when the tire is lifted from the ground;

[0008] obtaining a performance parameter of the target tire, and substituting the free radius, the first ground departure angle, and the performance parameter into a flexible ring model to calculate the load of the target tire; wherein the flexible ring model includes the contribution value of each performance parameter to the tire load distribution, and the performance parameter includes the tire internal air pressure and the tire stiffness;

[0009] obtaining the wheelbase and the width of the vehicle, and calculating the centroid position of the vehicle according to the load of the target tire, the wheelbase, and the width of the vehicle.

[0010] In one embodiment, obtaining an acceleration value and a free radius of a target tire, and calculating a first ground departure angle of the target tire based on the acceleration value and the free radius comprises:

[0011] calculating an arc length of a contact patch of the target tire according to the acceleration value;

[0012] calculating a tire circumference according to the free radius;

[0013] calculating the first ground departure angle according to the arc length of the contact patch and the tire circumference.

[0014] In one embodiment, the free radius, the first ground departure angle and the performance parameter are substituted into a flexible ring model to calculate the load of the target tire, including:

[0015] determining a first contribution value of deformation of the target tire under the internal air pressure to the load according to the internal air pressure of the tire, the free radius and the first ground departure angle;

[0016] determining a second contribution value of deformation of the target tire under the stiffness to the load according to the tire stiffness, the free radius and the first ground departure angle;

[0017] adding the first contribution value and the second contribution value to obtain the load of the target tire.

[0018] In one embodiment, the first contribution value is directly proportional to the sine value of the internal air pressure of the tire, the free radius and the first ground departure angle respectively; the second contribution value includes a first term and a second term, wherein the first term is directly proportional to the tire stiffness, the square of the free radius and the first ground departure angle respectively; the second term is directly proportional to the sine value of the tire stiffness, the square of the free radius and the first ground departure angle respectively.

[0019] In one embodiment, before obtaining the acceleration value and the free radius of the target tire and calculating the first ground departure angle of the target tire based on the acceleration value and the free radius, the method further includes:

[0020] establishing a regression equation according to the flexible ring model; wherein the regression equation contains the mapping relationship between the free radius, the ground departure angle, the tire performance and the load of the tire in the vehicle, and also contains coefficients to be solved;

[0021] collecting a second ground departure angle of the vehicle under different load calibration values, calculating the contribution value of each tire performance to the load, and weighting each part of the contribution value with the coefficients as weights to obtain a load prediction value of the tire in the vehicle;

[0022] solving the coefficients to minimize the error between the load prediction value and the load calibration value.

[0023] In one of the embodiments, the regression equation is established according to the flexible ring model, comprising:

[0024] determining a first mapping relationship between a deformation amount of a contact area of the tire and the free radius, the ground departure angle, and the tire performance;

[0025] determining a second mapping relationship between a load distribution of the tire when the tire contacts the ground and the free radius, the ground departure angle, and the tire performance;

[0026] obtaining the regression equation by combining the first mapping relationship and the second mapping relationship.

[0027] In one of the embodiments, the wheelbase and the width of the vehicle are obtained, and the mass center position of the vehicle is calculated according to the load of the target tire, the wheelbase and the width of the vehicle, comprising:

[0028] calculating the total load of the first target tire and the second target tire in the vehicle; wherein the first target tire is located in front of the second target tire;

[0029] calculating a first ratio between the load of the first target tire and the total load, and multiplying the first ratio by the wheelbase to obtain a coordinate of the mass center in the wheelbase direction;

[0030] calculating a second ratio between the load of the second target tire and the total load, and multiplying the second ratio by the width to obtain a coordinate of the mass center in the width direction;

[0031] determining the position of the mass center in the XOY plane according to the coordinates of the mass center in the wheelbase direction and the width direction.

[0032] In a second aspect, the present application provides a vehicle-mounted electronic device, comprising a memory and a processor, the memory stores a computer program, and the processor implements the steps of the method of the first aspect when executing the computer program.

[0033] In a third aspect, the present application provides a vehicle, comprising a vehicle body and the vehicle-mounted electronic device of the second aspect, the vehicle body comprises a tire, a sensor is installed on the tire, and the sensor is in communication connection with the vehicle-mounted electronic device.

[0034] In a fourth aspect, the present application provides a computer readable storage medium, which stores a computer program, and the computer program implements the steps of the method of the first aspect when executed by a processor.

[0035] The vehicle centroid identification method, the vehicle-mounted electronic device, the vehicle and the storage medium, by collecting the acceleration value of the tire in the vehicle in real time, calculating the first ground leaving angle of the corresponding tire according to the acceleration value and the free radius, and based on the free radius and the first ground leaving angle, the contribution value of different performance parameters to the tire load distribution is summarized to obtain the load of the tire, and the position of the vehicle centroid in XOY plane is calculated according to the load of the tire. By real-time calculation of the load of the tire, the centroid position of the vehicle in the XOY plane is obtained, the real-time and accurate feedback of the vehicle centroid is realized, and the problem of inaccurate vehicle centroid identification in the related art is solved. BRIEF DESCRIPTION OF DRAWINGS

[0036] Figure 1 It is a hardware structure block diagram of the vehicle-mounted electronic device in one embodiment;

[0037] Figure 2 It is a flow chart of the vehicle centroid identification method in one embodiment;

[0038] Figure 3 It is a simplified model diagram of the tire after compression in one embodiment;

[0039] Figure 4 It is a tire circumferential acceleration curve change diagram in one embodiment;

[0040] Figure 5 It is a flexible ring model coefficient calibration flow chart in one embodiment;

[0041] Figure 6 It is a summary model residual percentage distribution diagram in one embodiment. DETAILED DESCRIPTION

[0042] In order to make the purpose, technical scheme and advantages of the present application clearer, the present application is further described in detail below in combination with the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and do not limit the present application.

[0043] Unless otherwise defined, technical terms or scientific terms used in the present application shall have the same meaning as those commonly understood by a person of ordinary skill in the art to which the present application belongs. The terms "one", "a", "an", "the", "these", and similar terms in the present application do not mean "only one" or "exactly one", but can mean "one or more". The terms "include", "contain", "have", and any variant thereof in the present application are intended to cover the non-exclusive inclusion; for example, a process, method, system, product or device containing a series of steps or modules (units) is not limited to the listed steps or modules (units), but can include steps or modules (units) not listed, or can include other steps or modules (units) inherent to the process, method, product or device. The terms "connect", "connected", "couple" and the like in the present application are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. The term "multiple" in the present application means two or more. The term "and / or" describes the association relationship between the associated objects, which means that there can be three relationships, for example, "A and / or B" can mean that A exists alone, A and B exist together, and B exists alone. Generally, the character " / " means that the objects associated before and after are in an "or" relationship. The terms "first", "second", "third" and the like in the present application are only used to distinguish similar objects, and do not represent a specific order of the objects.

[0044] The method embodiments provided in the present application can be executed in a terminal, a computer or a similar computing device. For example, the method embodiments can be executed on a vehicle-mounted electronic device, Figure 1 is a hardware structure diagram of a vehicle-mounted electronic device according to an embodiment of the present application. As shown in Figure 1 , the vehicle-mounted electronic device can include one or more (only one is shown in Figure 1 ) processors 101 and a memory 102 for storing data, wherein the processor 101 can include but is not limited to a processing device such as a microprocessor MCU or a programmable logic device FPGA. The above vehicle-mounted electronic device can also include a transmission device 103 for communication function and an input / output device 104. Those skilled in the art can understand that Figure 1 The structure shown is only schematic, which does not limit the structure of the above vehicle-mounted electronic device. For example, the vehicle-mounted electronic device can also include more or fewer components than those shown in Figure 1 , or have a different configuration from that shown in Figure 1 .

[0045] The memory 102 can be used to store computer programs, such as software programs of application software and modules, such as the computer program corresponding to the vehicle centroid identification method in the embodiment. The processor 101 executes various functional applications and data processing, i.e., implements the above method, by running the computer program stored in the memory 102. The memory 102 can include a high-speed random access memory, and can also include a non-volatile memory, such as one or more magnetic storage devices, flash memories, or other non-volatile solid-state memories. In some examples, the memory 102 can further include a memory remotely arranged with respect to the processor 101, which can be connected to the vehicle electronic device through a network. Examples of the above network include but are not limited to the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0046] The transmission device 103 is used to receive or send data via a network. The above network includes a wireless network provided by a communication provider of the vehicle electronic device. In one example, the transmission device 103 includes a network adapter (NIC), which can be connected to other network devices through a base station to communicate with the Internet. In one example, the transmission device 103 can be a radio frequency (RF) module, which is used to communicate with the Internet in a wireless manner.

[0047] The traditional vehicle centroid identification method has the following problems:

[0048] Static measurement limitation: Current vehicle centroid identification methods mostly rely on static measurement, which cannot adapt to real-time changes of the centroid under dynamic driving conditions. This leads to the fact that the centroid data obtained in complex driving environments is often not accurate enough to reflect the true situation of the vehicle in different states.

[0049] Lack of real-time performance: The traditional method does not fully consider the application of real-time data when calculating the vehicle centroid, and lacks the response ability to instantaneous state changes. This makes it difficult for the system to provide timely and effective feedback in rapidly changing driving environments, and cannot meet the needs of modern intelligent driving.

[0050] Poor data integration capability: The traditional method fails to effectively integrate various data from different tire sensors, resulting in an inability to comprehensively evaluate the dynamic behavior of the vehicle and its centroid changes. This information island phenomenon makes it difficult for the vehicle control system to obtain comprehensive data support, thereby limiting its decision-making ability.

[0051] Poor environmental adaptability: traditional methods lack adaptability to different road conditions and driving habits, and cannot provide a unified solution. This limitation affects the universal applicability of the system in various driving scenarios, making it difficult to be widely applied in actual driving situations.

[0052] Complex algorithm dependence: traditional methods rely on complex algorithm models, which have a cumbersome calculation process and poor real-time performance. This complexity not only increases the difficulty of implementation, but also limits the popularization and dissemination of these technologies in practical applications.

[0053] Based on the analysis of the above situation, in one embodiment, Figure 2 a flowchart of a vehicle centroid identification method is provided, which is applied to Figure 1 the vehicle-mounted electronic device in , including the following steps:

[0054] Step S101, obtaining the acceleration value and free radius of the target tire, and calculating the first ground leaving angle of the target tire based on the acceleration value and free radius; wherein the first ground leaving angle is the maximum angle between the ground contact area of the tire and the vertical direction when the tire is lifted from the ground.

[0055] Figure 3 The simplified model diagram of the tire after compression in this embodiment is shown in Figure 3 , where O represents the center of the tire (i.e. the center of the circle), R represents the free radius of the tire, A and B represent the contact points formed with the ground due to deformation during tire rolling. OC is perpendicular to AB, the arc length AB represents the contact area, θ is the angle between the position of the sensor in the tire and the vertical direction, θ will change in real time, θf is the entering angle of the tire contact area, and θr is the leaving angle of the tire contact area. Assuming that the deformation of the tire in the contact area is symmetrical, i.e. θf = θr.

[0056] When calculating the first ground leaving angle of the corresponding tire based on the acceleration value and free radius, the arc length AB of the corresponding tire contact area can be calculated based on the acceleration value; the tire circumference 2πR can be calculated based on the free radius; and the first ground leaving angle θr can be calculated based on the arc length AB of the contact area and the tire circumference 2πR.

[0057] In practical applications, a sensor (such as an accelerometer or a smart tire sensor) can be attached inside the tire to collect the tire circumferential (X-direction) acceleration value in real time. Figure 4 The tire circumferential acceleration curve change diagram in this embodiment is shown in Figure 4 , where the horizontal axis represents time (in ms) and the vertical axis represents the circumferential acceleration amplitude (in m / S 2 ). From Figure 4It can be seen that the circumferential acceleration amplitude fluctuates around zero. Due to the deformation caused by the contact between the tire and the road, there is a maximum value (P1, P2, P3, P4) and a minimum value (V1, V2, V3, V4) before and after the tire contacts the ground. When the intelligent tire sensor rolls to the front end of the contact, the tread rubber is suddenly compressed, causing the circumferential acceleration amplitude to increase; when the intelligent tire sensor rolls to the rear end of the contact, the compressed rubber suddenly releases and recovers, causing the circumferential acceleration amplitude to increase again; the directions of the two mutations are opposite, corresponding to a positive and a negative circumferential acceleration extreme value.

[0058] Take the circumferential acceleration data within 1s as a frame, as the analysis duration. It can be seen that within 1s, the tire rotates 4 times, V1~V2 corresponds to the peak value when the tire starts to contact the ground, P1~P4 corresponds to the peak value when the tire starts to leave the ground. In addition, adjacent P or adjacent V corresponds to one rotation of the tire, for example, the acceleration amplitude experiences P1, V2, P2 in turn, or the acceleration amplitude experiences V1, P1 in turn. Adjacent PV corresponds to the duration of the tire contacting the ground, for example, the acceleration amplitude experiences V1, P1 in turn, or the acceleration amplitude experiences V2, P2 in turn.

[0059] According to the duration t of the tire contacting the ground and the acceleration value a, the travel distance l of the tire, i.e. the arc length of the contact area, is calculated as l = at 2 , and the circumference of the tire is calculated according to the free radius 2πR. The first contact and departure angle is:

[0060] θr = length of V1~P1 ÷ length of P1~P2 × 2π

[0061] Substituting the relevant parameters, we get:

[0062] θr = at 2 ÷ 2πR × 2π = at 2 / R

[0063] In step S102, the performance parameters of the target tire are obtained, and the free radius, the first contact and departure angle, and the performance parameters are substituted into the flexible ring model to calculate the load of the target tire; wherein the flexible ring model contains the contribution value of each performance parameter to the tire load distribution, and the performance parameters include the internal air pressure of the tire and the tire stiffness.

[0064] In this step, the performance parameter contribution value to the tire load distribution can be calculated according to the free radius and the first ground departure angle, and the partial contribution values are added to obtain the load of the target tire. Specifically, the first contribution value of the deformation of the target tire under the action of the internal air pressure to the load is determined according to the internal air pressure of the tire, the free radius and the first ground departure angle; the second contribution value of the deformation of the target tire under the action of the stiffness to the load is determined according to the tire stiffness, the free radius and the first ground departure angle; the first contribution value and the second contribution value are added to obtain the load of the target tire.

[0065] In step S103, the wheelbase and the width of the vehicle are obtained, and the mass center position of the vehicle is calculated according to the load of the target tire, the wheelbase and the width of the vehicle.

[0066] In this step, the total load of the first target tire and the second target tire in the vehicle can be calculated; the first target tire is located in front of the second target tire; the first ratio between the load of the first target tire and the total load is calculated, and the first ratio is multiplied by the wheelbase to obtain the coordinate of the mass center in the wheelbase direction; the second ratio between the load of the second target tire and the total load is calculated, and the second ratio is multiplied by the width to obtain the coordinate of the mass center in the width direction; the position of the mass center in the XOY plane is determined according to the coordinates of the mass center in the wheelbase direction and the width direction. The first target tire and the second target tire can be all the tires in the vehicle, or part of the tires in the vehicle.

[0067] In some embodiments, for a four-wheel vehicle, there are a left front wheel, a right front wheel, a left rear wheel and a right rear wheel, the left front wheel and the right front wheel are divided into the first target tire, and the load cumulative value of the left front wheel and the right front wheel is defined as the first load value; the left rear wheel and the right rear wheel are divided into the second target tire, and the load cumulative value of the left rear wheel and the right rear wheel is defined as the second load value. The total load of the first target tire and the second target tire is calculated, that is, the total load of the left front wheel, the right front wheel, the left rear wheel and the right rear wheel in the vehicle is calculated; the first ratio between the first load value and the total load is calculated, and the first ratio is multiplied by the wheelbase to obtain the coordinate of the mass center in the wheelbase direction; the second ratio between the second load value and the total load is calculated, and the second ratio is multiplied by the width to obtain the coordinate of the mass center in the width direction; the position of the mass center in the XOY plane is determined according to the coordinates of the mass center in the wheelbase direction and the width direction.

[0068] Assuming that the wheelbase of the vehicle is L, the width of the vehicle is B, and the real-time loads of the left front wheel, the right front wheel, the left rear wheel and the right rear wheel are W FL , W FR , W RL and W RR , respectively.

[0069] The coordinate of the mass center in the X direction (the wheelbase direction of the vehicle) is:

[0070] (W FL +W FR ) / (W FL +W FR +W RL +W RR )×L;

[0071] The coordinate of the center of mass in the Y direction (the vehicle width direction) is:

[0072] (W FL +W RL ) / (W FL +W FR +W RL +W RR )×B.

[0073] In some embodiments, for the center of mass calculation of a four-wheel vehicle, when the first target tire and the second target tire participating in the calculation are selected, the first target tire can be the left front wheel and / or the right front wheel, and the second target tire can be the left rear wheel and / or the right rear wheel. In some embodiments, for the center of mass calculation of an N-wheel vehicle, when the first target tire and the second target tire participating in the calculation are selected, the first target tire can be any one or more of the front wheels, and the second target tire can be any one or more of the rear wheels.

[0074] In the above manner, the real-time center of mass position of the vehicle in the XOY plane can be obtained. The center of mass position can be used as effective information input for automatic driving, ensuring high-precision tracking of vehicle driving.

[0075] In the above steps S101 to S103, by collecting the acceleration values of the tires in the vehicle in real time, the first ground departure angle of the corresponding tire is calculated according to the acceleration values and the free radius, and based on the free radius and the first ground departure angle, the contribution values of different performance parameters to the tire load distribution are summarized to obtain the tire load, and the position of the center of mass of the vehicle in the XOY plane is calculated according to the tire load. By calculating the tire load in real time, the position of the center of mass of the vehicle in the XOY plane is obtained, the center of mass of the vehicle is fed back in real time and accurately, and the problem of inaccurate vehicle center of mass recognition in the related art is solved.

[0076] In one embodiment, the first contribution value is proportional to the tire internal pressure, the free radius, and the sine value of the first ground departure angle, respectively; the second contribution value includes a first term and a second term, wherein the first term is proportional to the tire stiffness, the square of the free radius, and the first ground departure angle, respectively; and the second term is proportional to the tire stiffness, the square of the free radius, and the sine value of the first ground departure angle, respectively.

[0077] Specifically, the calculation formula of the flexible ring model is as follows:

[0078] Qw = 2 x R x p0 x b x sin θr + R 2 x K x (sin θr - θr x b)

[0079] Wherein, Qw is the tire load, p0 is the tire internal pressure, θr is the tire contact area departure angle, K is the tire stiffness (specifically the total stiffness in xy direction), R is the tire free radius. 2 x R x p0 x b x sin θr is the first contribution value, R 2 x K x (sin θr - θr x b) is the second contribution value.

[0080] Simplify the above flexible ring model, a regression equation can be established:

[0081] Qw = x1 x p0 x R x sin θr + x2 x R 2 x K x θr + R 2 x K x sin θr

[0082] Wherein, (x1 x p0 x R x sin θr) is the first contribution value, (x2 x R 2 x K x θr + R 2 x K x sin θr) is the second contribution value. Wherein, (x2 x R 2 x K x θr) is the first term of the second contribution value, (R 2 x K x sin θr) is the second term of the second contribution value. x1 and x2 are model coefficients, related to tire specifications, brands, and can be calculated by calibration.

[0083] In one embodiment, Figure 5 A flexible ring model coefficient calibration flowchart is provided, as Figure 5 shown, before obtaining the acceleration value and the free radius of the target tire and calculating the first ground departure angle of the target tire based on the acceleration value and the free radius, the method further comprises the following steps:

[0084] Step S201, a regression equation is established according to the flexible ring model; wherein the regression equation contains the mapping relationship between the free radius, the ground departure angle, the tire performance and the load of the tire in the vehicle, and also contains the coefficients to be solved.

[0085] Determine the first mapping relationship between the deformation of the tire contact area and the free radius, the ground departure angle; determine the second mapping relationship between the load distribution when the tire contacts the ground and the free radius, the ground departure angle, the tire performance; combine the first mapping relationship and the second mapping relationship to obtain the regression equation.

[0086] Specifically, assuming that the deformation of the tire contact area is δ, and the maximum deformation of the tire in the contact area is a, wherein a = CD, then:

[0087]

[0088] Assuming that the deformation of the tire at the contact patch is symmetrical, i.e. θf = θr, and because θ and θr are close in value, it can be assumed that a = R - R x cos θr, and thus the above equation can be simplified as:

[0089]

[0090] Therefore, the load of the tire can be simplified as:

[0091]

[0092] where qw is the load distribution of the tire.

[0093] Substituting the above equations into the flexible ring model of the tire, we can obtain:

[0094] Qw = 2 x R x p0 x b x sin θr + R 2 x K x (sin θr - θr x b)

[0095] Based on the above equation, a regression equation can be established:

[0096] Qw = x1 x p0 x R x sin θr + x2 x R 2 x K x θr + R 2 x K x sin θr

[0097] Step S202, collect the second contact patch departure angle of the vehicle under different load calibration values, calculate the contribution value of each tire performance to the load, and weight each part of the contribution value with the coefficient as the weight to obtain the load prediction value of the tire in the vehicle.

[0098] The acceleration value and internal pressure of the tire can be collected by the intelligent tire sensor, the second contact patch departure angle can be calculated, and then the free radius of the tire, the second contact patch departure angle, the internal pressure, and the stiffness are substituted into the above regression equation to calculate the load prediction value.

[0099] Step S203, solve the coefficients by minimizing the error between the load prediction value and the load calibration value. In actual application, a tire drum tester or a six-component tester can be used to set different load test conditions, run for 1 minute under each test condition, and output the corresponding θr through the sensor. Summarize θr under different loads, corresponding to different load data, complete the model calibration. The following table is the input parameters and calibration parameters of the model. Substituting these data into the regression equation, the model coefficients x1 and x2 can be solved.

[0100]

[0101] Optionally, in the actual calibration process, 70% of the data is used for model calibration, and 30% of the data is used for model verification. To judge the pros and cons of the model, the summary model residual percentage distribution chart is used, and the correlation coefficient of the model is viewed at the same time. Figure 6 For the summary model residual percentage distribution chart of the present embodiment, as shown in Figure 6 the horizontal coordinate represents the test load (unit: kg), and the vertical coordinate represents the residual ratio. According to the test results, the correlation coefficient = 0.9920 can be obtained. From the figure, it can be concluded that the model error is controlled within ±5, the accuracy is higher than that based on the traditional torque input, the correlation coefficient is more than 99%, and the effect is good.

[0102] In one embodiment, an intelligent tire sensor is installed on the tire to collect the acceleration value and internal air pressure of the tire in real time. The calibrated model coefficient, tire free radius, tire lateral and longitudinal total stiffness, vehicle wheelbase and width are stored in the ECU (Electronic Control Unit) of the vehicle. The vehicle centroid recognition method of any one of the above embodiments is executed based on the ECU to realize the recognition of the vehicle centroid. In this way, the load of each wheel position, rather than each axle position, can be obtained in real time, because the single wheel position load estimation accuracy is higher than that of the traditional torque output based estimation method. The centroid positions of the front and rear axes and the left and right ends in the XOY plane can be obtained at the same time. The traditional torque output based method can only obtain the load of the front and rear axes. The calibration is simple and can be completed before the tire is shipped. The key parameters related to the wheel load are obtained through the flexible ring model, and the correlation between the model and the tire load is more than 99%.

[0103] In one embodiment, a vehicle is provided, which includes a vehicle body and the above vehicle-mounted electronic device. The vehicle body includes a tire, and a sensor is installed on the tire and is in communication connection with the vehicle-mounted electronic device. The sensor can be an accelerometer or an intelligent tire sensor, wherein the accelerometer is used to collect the acceleration value of the tire, and the intelligent tire sensor is used to collect the acceleration value and internal air pressure of the tire. The vehicle-mounted electronic device calculates the vehicle centroid position based on the data collected by the sensor and the pre-stored parameters (calibrated model coefficient, tire free radius, tire lateral and longitudinal total stiffness, vehicle wheelbase and width).

[0104] It should be noted that the specific examples in the present embodiment can refer to the examples described in the above embodiments and optional implementation manners, which will not be described herein again.

[0105] In addition, in combination with the vehicle centroid recognition method provided in the above embodiments, a storage medium can also be provided to realize the vehicle centroid recognition method in the present embodiment. The storage medium has a computer program stored thereon; and the computer program is executed by a processor to realize any one of the vehicle centroid recognition methods in the above embodiments.

[0106] In one embodiment, the computer program, when executed by the processor, implements the following steps:

[0107] obtaining an acceleration value and a free radius of the target tire, and calculating a first ground departure angle of the target tire based on the acceleration value and the free radius; wherein the first ground departure angle is a maximum angle between a ground contact area of the tire and a vertical direction when the tire is lifted from the ground;

[0108] obtaining a performance parameter of the target tire, and substituting the free radius, the first ground departure angle and the performance parameter into a flexible ring model to calculate a load of the target tire; wherein the flexible ring model contains a contribution value of each performance parameter to the load distribution of the tire, and the performance parameter includes an internal air pressure of the tire and a tire stiffness;

[0109] obtaining a wheelbase and a width of the vehicle, and calculating a center of mass position of the vehicle according to the load of the target tire, the wheelbase and the width of the vehicle.

[0110] In one embodiment, the computer program, when executed by the processor, further implements the following steps:

[0111] calculating an arc length of the ground contact area of the target tire according to the acceleration value;

[0112] calculating a tire circumference according to the free radius;

[0113] calculating the first ground departure angle according to the arc length of the ground contact area and the tire circumference.

[0114] In one embodiment, the computer program, when executed by the processor, further implements the following steps:

[0115] determining a first contribution value of a deformation of the target tire under the action of the internal air pressure to the load according to the internal air pressure, the free radius and the first ground departure angle;

[0116] determining a second contribution value of a deformation of the target tire under the action of the stiffness to the load according to the tire stiffness, the free radius and the first ground departure angle;

[0117] adding the first contribution value and the second contribution value to obtain the load of the target tire.

[0118] In one embodiment, the computer program, when executed by the processor, further implements the following steps:

[0119] The first contribution value is directly proportional to the sine values of the internal air pressure, the free radius and the first ground departure angle of the tire respectively; the second contribution value includes a first term and a second term, wherein the first term is directly proportional to the tire stiffness, the square of the free radius and the first ground departure angle respectively; and the second term is directly proportional to the sine values of the tire stiffness, the square of the free radius and the first ground departure angle respectively.

[0120] In one embodiment, the computer program, when executed by the processor, further implements the following steps:

[0121] establishing a regression equation according to the flexible ring model; wherein the regression equation contains a mapping relationship between the free radius, the ground departure angle of the tire in the vehicle, the tire performance and the load, and also contains a coefficient to be solved;

[0122] collecting the second ground departure angle of the vehicle under different load calibration values, calculating the contribution value of each tire performance to the load, and weighting each part of the contribution value with the coefficient as the weight to obtain the load prediction value of the tire in the vehicle;

[0123] solving the coefficient by minimizing the error between the load prediction value and the load calibration value.

[0124] In one embodiment, the computer program, when executed by the processor, further implements the following steps:

[0125] determining a first mapping relationship between the deformation of the contact area of the tire and the free radius and the ground departure angle;

[0126] determining a second mapping relationship between the load distribution when the tire contacts the ground and the free radius, the ground departure angle and the tire performance;

[0127] obtaining a regression equation by combining the first mapping relationship and the second mapping relationship.

[0128] In one embodiment, the computer program, when executed by the processor, further implements the following steps:

[0129] calculating the total load of the first target tire and the second target tire in the vehicle; wherein the first target tire is located in front of the second target tire;

[0130] calculating a first ratio between the load of the first target tire and the total load, and multiplying the first ratio by the wheelbase to obtain the coordinates of the center of mass in the direction of the wheelbase;

[0131] calculating a second ratio between the load of the second target tire and the total load, and multiplying the second ratio by the width to obtain the coordinates of the center of mass in the direction of the width;

[0132] determining the position of the center of mass in the XOY plane according to the coordinates of the center of mass in the direction of the wheelbase and the direction of the width.

[0133] It should be noted that the user information (including but not limited to user equipment information, user personal information, etc.) and data (including but not limited to data for analysis, stored data, displayed data, etc.) involved in the present application are all information and data authorized by the user or authorized by all parties.

[0134] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a non-volatile computer readable storage medium, and when the computer program is executed, the processes of the above-mentioned embodiments of the methods can be included. Any reference to memory, database or other medium used in the embodiments provided in the present application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (Read-Only Memory, ROM), magnetic tape, floppy disk, flash memory, optical storage, high-density embedded non-volatile memory, resistive memory (ReRAM), magnetoresistive random access memory (Magnetoresistive Random Access Memory, MRAM), ferroelectric memory (Ferroelectric Random Access Memory, FRAM), phase change memory (Phase Change Memory, PCM), graphene memory, etc. Volatile memory can include random access memory (Random Access Memory, RAM) or external cache memory, etc. As an illustration but not limitation, RAM can be in various forms, such as static random access memory (Static Random Access Memory, SRAM) or dynamic random access memory (Dynamic Random Access Memory, DRAM), etc. The database involved in the embodiments provided in the present application can include at least one of a relational database and a non-relational database. The non-relational database can include a distributed database based on a block chain, etc., without being limited thereto. The processor involved in the embodiments provided in the present application can be a general-purpose processor, a central processing unit, a graphics processing unit, a digital signal processor, a programmable logic device, a data processing logic device based on quantum computing, etc., without being limited thereto.

[0135] Any combination of the technical features of the above embodiments can be made. In order to make the description simple, all possible combinations of the technical features in the above embodiments are not described, however, as long as the combination of the technical features does not exist contradictory, it should be considered as the scope of the present application.

[0136] The above embodiments only express several implementation manners of the present application, and the description is more specific and detailed, but it should not be understood as a limitation on the scope of the patent of the present application. It should be pointed out that for ordinary skilled in the art, without departing from the concept of the present application, some modifications and improvements can be made, which are within the scope of protection of the present application. Therefore, the protection scope of the present application should be subject to the appended claims.

Claims

1. A vehicle center of mass identification method, characterized by, The method comprises: obtaining the acceleration value and the free radius of the target tire, and calculating the first ground departure angle of the target tire based on the acceleration value and the free radius; wherein the first ground departure angle is the maximum angle between the ground contact area of the tire and the vertical direction when the tire is lifted from the ground; obtaining the performance parameters of the target tire, and substituting the free radius, the first ground departure angle and the performance parameters into the flexible ring model to calculate the load of the target tire; wherein the flexible ring model contains the contribution value of each performance parameter to the tire load distribution, and the performance parameters include the tire internal pressure and the tire stiffness; obtaining the wheelbase and width of the vehicle, and calculating the center of mass position of the vehicle according to the load of the target tire, the wheelbase and the width of the vehicle.

2. The vehicle center-of-gravity identification method according to claim 1, characterized by, obtaining the acceleration value and the free radius of the target tire, and calculating the first ground departure angle of the target tire based on the acceleration value and the free radius, comprising: calculating the arc length of the ground contact area of the target tire according to the acceleration value; calculating the tire circumference according to the free radius; calculating the first ground departure angle according to the arc length of the ground contact area and the tire circumference.

3. The vehicle center of mass identification method of claim 1, wherein Substituting the free radius, the first ground departure angle and the performance parameters into the flexible ring model to calculate the load of the target tire, comprising: determining the first contribution value of the deformation of the target tire under the action of the internal pressure to the load according to the tire internal pressure, the free radius and the first ground departure angle; determining the second contribution value of the deformation of the target tire under the action of the stiffness to the load according to the tire stiffness, the free radius and the first ground departure angle; adding the first contribution value and the second contribution value to obtain the load of the target tire.

4. The vehicle center-of-gravity identification method according to claim 3, characterized by, The first contribution value is proportional to the sine value of the tire internal pressure, the free radius and the first ground departure angle respectively; the second contribution value includes a first term and a second term, wherein the first term is proportional to the tire stiffness, the square of the free radius and the first ground departure angle respectively; and the second term is proportional to the sine value of the tire stiffness, the square of the free radius and the first ground departure angle respectively.

5. The vehicle center of mass identification method of claim 1, wherein Before obtaining the acceleration value and the free radius of the target tire, and calculating the first ground departure angle of the target tire based on the acceleration value and the free radius, the method further comprises: establishing a regression equation according to the flexible ring model; wherein the regression equation contains the mapping relationship between the free radius, the ground departure angle, the tire performance and the load of the tire in the vehicle, and also contains the coefficients to be solved; collecting the second ground departure angle of the vehicle under different load calibration values, calculating the contribution value of each tire performance to the load, and weighting each part of the contribution value with the coefficients to obtain the load prediction value of the tire in the vehicle; solving the coefficients by minimizing the error between the load prediction value and the load calibration value.

6. The vehicle center of mass identification method according to claim 5, characterized by, establishing a regression equation according to the flexible ring model, comprising: determine a first mapping relationship between a deformation amount of a contact area of the tire and the free radius, the ground departure angle, and the tire performance; determine a second mapping relationship between a load distribution of the tire when the tire contacts the ground and the free radius, the ground departure angle, and the tire performance; obtain the regression equation by combining the first mapping relationship and the second mapping relationship.

7. The vehicle center of mass identification method of claim 1, wherein obtain a wheelbase and a width of the vehicle, and calculate a mass center position of the vehicle according to a load of the target tire, the wheelbase and the width of the vehicle, including: calculating a total load of a first target tire and a second target tire in the vehicle, wherein the first target tire is located in front of the second target tire; calculating a first ratio between the load of the first target tire and the total load, and multiplying the first ratio by the wheelbase to obtain a coordinate of the mass center in a wheelbase direction; calculating a second ratio between the load of the second target tire and the total load, and multiplying the second ratio by the width to obtain a coordinate of the mass center in a width direction; determining a position of the mass center in an XOY plane according to the coordinates of the mass center in the wheelbase direction and the width direction.

8. An in-vehicle electronic device comprising a memory and a processor, the memory storing a computer program, characterized by, The processor implements the steps of the method of any one of claims 1 to 7 when executing the computer program.

9. A vehicle characterized by comprising: including: a vehicle body and the vehicle-mounted electronic device of claim 8, the vehicle body including a tire, a sensor being installed on the tire, and the sensor being in communication connection with the vehicle-mounted electronic device.

10. A computer-readable storage medium having stored thereon a computer program, characterized in that, The computer program is executed by the processor to implement the steps of the method of any one of claims 1 to 7.

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