A control method and device for vehicle hill start

Abstract

This application relates to a method and device for controlling a vehicle hill start. The method includes: upon recognizing that the vehicle is currently on a slope and receiving a start command, obtaining the current slope and the current adhesion coefficient under current weather conditions; deriving the minimum driving torque required for the vehicle based on the current slope and the current adhesion coefficient; determining a current slope compensation coefficient when the current driving torque indicated by the start command is less than the minimum driving torque; deriving a final driving torque based on the current slope compensation coefficient and the current driving torque, and controlling the vehicle's start based on the final driving torque. This method can improve the user's driving experience compared to existing technologies.

Description

Technical Field

[0001] The present application relates to the field of new energy vehicle control technology, and in particular to a control method and device for vehicle hill start. Background Art

[0002] Currently, some new energy vehicles lack the Electronic Stability Program (ESP), or those that do lack the hill-start assist function. When starting on a slope, the torque provided by the accelerator pedal is insufficient to generate sufficient starting force, causing the vehicle to stall or even roll.

[0003] The existing hill start assist function is highly dependent on the vehicle chassis. It has a single function and great limitations. It is difficult to be compatible with various driving scenarios, making it difficult for users to experience a more comfortable and practical assisted driving function.

[0004] Therefore, the driving experience of users in the existing technology needs to be improved. Summary of the Invention

[0005] Based on this, a control method and device for vehicle hill start are provided to improve the user's driving experience in the prior art.

[0006] In a first aspect, a method for controlling a vehicle starting on a hill is provided, the method comprising:

[0007] When the vehicle is identified as being on a slope and a start command is received, the current slope and the current adhesion coefficient under the current weather conditions are obtained;

[0008] obtaining a minimum driving torque currently required by the vehicle according to the current slope and the current adhesion coefficient;

[0009] determining a current slope compensation coefficient when the current driving torque indicated by the starting instruction is less than the minimum driving torque;

[0010] A final driving torque is obtained according to the current slope compensation coefficient and the current driving torque, and the current vehicle starting is controlled according to the final driving torque.

[0011] In conjunction with the first aspect, in a first possible implementation of the first aspect, the step of obtaining the current slope includes:

[0012] Collecting the longitudinal acceleration of the current vehicle in the direction of travel and the lateral acceleration horizontally perpendicular to the direction of travel;

[0013] The current slope is calculated according to the longitudinal acceleration and the lateral acceleration, wherein the mathematical expression for calculating the current slope includes:

[0014] θ=arctan[(a x -a y ) / g]

[0015] θ is the current slope, a x is the lateral acceleration, a y is the longitudinal acceleration, and g is the acceleration due to gravity.

[0016] In combination with the first aspect, in a second possible implementation of the first aspect, the step of obtaining the current adhesion coefficient under the current weather conditions includes:

[0017] Collect the current temperature under the current weather conditions;

[0018] Acquire a first mapping relationship between temperature and adhesion coefficient, and obtain the current adhesion coefficient according to the current temperature and the first mapping relationship; or,

[0019] Collect the current temperature and rainfall under the current weather conditions;

[0020] A second mapping relationship among temperature, rainfall, and adhesion coefficient is acquired, and the current adhesion coefficient is obtained according to the current temperature, the current rainfall, and the second mapping relationship.

[0021] In combination with the second possible implementation manner of the first aspect, in a third possible implementation manner of the first aspect, the step of obtaining a first mapping relationship between temperature and adhesion coefficient includes:

[0022] Acquire a first test data set, wherein the first test data set includes a plurality of first data groups, each of the first data groups includes a first test temperature and a first test adhesion coefficient;

[0023] The first test data set is fitted to obtain a first mapping relationship between the temperature and the adhesion coefficient.

[0024] In combination with the second possible implementation manner of the first aspect, in a fourth possible implementation manner of the first aspect, the step of obtaining a second mapping relationship between temperature, rainfall, and adhesion coefficient includes:

[0025] Acquire a second test data set, wherein the second test data set includes a plurality of second data groups, each of the second data groups includes a second test temperature, a test rainfall, and a second test adhesion coefficient;

[0026] The second test data set is fitted to obtain a second mapping relationship among the temperature, the rainfall, and the adhesion coefficient.

[0027] In combination with the first aspect, in a fifth possible implementation manner of the first aspect, the step of obtaining the minimum driving torque currently required by the vehicle based on the current slope and the current adhesion coefficient includes:

[0028] Obtaining the total weight of the current vehicle, wherein the total weight includes the weight of the current vehicle itself and the weight of the user in the current vehicle;

[0029] Calculate friction force according to the total weight, the current slope, and the current adhesion coefficient, wherein the mathematical expression for calculating the friction force includes:

[0030] f=K t *G*g*cosθ

[0031] f is the friction force, K t is the current adhesion coefficient, G is the total weight, g is the acceleration due to gravity, and θ is the current slope;

[0032] The minimum driving torque is calculated according to the friction force, the total weight, and the current slope, wherein the mathematical expression for calculating the minimum driving torque includes:

[0033] F1=f+G*g*sinθ

[0034] F1 is the minimum driving torque.

[0035] In combination with the first aspect, in a sixth possible implementation of the first aspect, the step of determining the current slope compensation coefficient includes:

[0036] Obtaining a third mapping relationship between the slope and the slope compensation coefficient;

[0037] Obtaining an initial compensation coefficient according to the current slope and the third mapping relationship;

[0038] Obtaining a fourth mapping relationship between the torque difference and the slope compensation coefficient;

[0039] obtaining a current torque difference according to the current driving torque and the minimum driving torque, and obtaining a dynamic compensation coefficient according to the current torque difference and the fourth mapping relationship;

[0040] Determining whether the initial compensation coefficient is greater than the dynamic compensation coefficient;

[0041] If so, using the initial compensation coefficient as the current slope compensation coefficient;

[0042] If not, the dynamic compensation coefficient is used as the current slope compensation coefficient.

[0043] In combination with the sixth possible implementation manner of the first aspect, in a seventh possible implementation manner of the first aspect, the step of obtaining a third mapping relationship between the slope and the slope compensation coefficient includes:

[0044] Acquire a third test data set, wherein the third test data set includes a plurality of third data groups, each of the third data groups includes a test slope and a first test slope compensation coefficient;

[0045] The third test data set is fitted to obtain a third mapping relationship between the slope and the slope compensation coefficient.

[0046] In combination with the sixth possible implementation manner of the first aspect, in an eighth possible implementation manner of the first aspect, the step of obtaining a fourth mapping relationship between the torque difference and the slope compensation coefficient includes:

[0047] Acquire a fourth test data set, wherein the fourth test data set includes a plurality of fourth data groups, each of the fourth data groups includes a test torque difference value and a second test slope compensation coefficient;

[0048] The fourth test data set is fitted to obtain a fourth mapping relationship between the torque difference and the slope compensation coefficient.

[0049] In a second aspect, a control device for a vehicle hill start is provided, characterized in that the device comprises:

[0050] A parameter acquisition module, upon recognizing that the vehicle is currently on a slope and receiving a start command, acquires the current slope and the current adhesion coefficient under the current weather conditions;

[0051] a parameter processing module, which obtains the minimum driving torque required by the current vehicle according to the current slope and the current adhesion coefficient;

[0052] a compensation coefficient determining module, configured to determine a current slope compensation coefficient when the current driving torque indicated by the starting instruction is less than the minimum driving torque;

[0053] The control module obtains a final driving torque according to the current slope compensation coefficient and the current driving torque, and controls the current vehicle to start according to the final driving torque.

[0054] The above-described vehicle hill start control method and device, upon recognizing that the vehicle is currently on a slope and receiving a start command, obtains the current slope and the current adhesion coefficient under the current weather conditions; based on the current slope and the current adhesion coefficient, obtains the minimum driving torque required by the vehicle; when the current driving torque indicated by the start command is less than the minimum driving torque, determines the current slope compensation coefficient; based on the current slope compensation coefficient and the current driving torque, obtains the final driving torque, and controls the vehicle's start based on the final driving torque. Thus, in a hill start scenario, the present application can calculate the slope compensation coefficient based on the real-time slope and the adhesion coefficient under the real-time weather conditions. The final driving torque obtained based on the slope compensation coefficient can drive the vehicle to start, which not only prevents the vehicle from rolling to a certain extent, but also accommodates driving scenarios in various weather conditions, thereby improving the user's driving experience compared to existing technologies. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] Figure 1 1 is a flow chart of a method for controlling a vehicle starting on a hill in one embodiment;

[0056] Figure 2 Schematic diagram of the relationship between the accelerator pedal opening, the vehicle speed corresponding to the accelerator pedal opening, and the current driving torque in one embodiment;

[0057] Figure 3 A schematic diagram of force decomposition of a vehicle on a slope in one embodiment;

[0058] Figure 4 A structural block diagram of a control device for starting a vehicle on a hill in one embodiment;

[0059] Figure 5 FIG. 1 is a structural block diagram of a control device for starting a vehicle on a hill in one embodiment. DETAILED DESCRIPTION

[0060] In order to make the purpose, technical solutions and advantages of this application more clear, the following further describes this application in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0061] It should be noted that the illustrations provided in this embodiment only illustrate the basic concept of the present application in a schematic manner. Therefore, the illustrations only show components related to the present application and are not drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component can be changed at will, and the component layout type may also be more complicated.

[0062] The structures, proportions, sizes, etc. illustrated in the drawings in this specification are only used to match the contents disclosed in the specification so as to facilitate understanding and reading by persons familiar with this technology. They are not intended to limit the conditions under which this application can be implemented, and therefore have no substantive technical significance. Any structural modifications, changes in proportional relationships, or adjustments in size, without affecting the efficacy and objectives that can be achieved by this application, should still fall within the scope of the technical contents disclosed in this application.

[0063] The directions or positional relationships indicated in this specification, such as "upper," "lower," "left," "right," "center," "longitudinal," "transverse," "horizontal," "inner," "outer," "radial," and "circumferential," are based on the directions or positional relationships shown in the accompanying drawings and are intended solely for the purpose of simplifying the description. They do not indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation, and therefore should not be construed as limitations on this application. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0064] Currently, some new energy vehicles lack electronic stability control systems (ESSs), or those that do have them lack hill-start assist. Consequently, these vehicles are prone to stalling or even rolling when starting on a slope. However, existing hill-start assist features rely heavily on the vehicle chassis, offer limited functionality, and are difficult to adapt to various driving scenarios in varying weather conditions, resulting in a poor driving experience.

[0065] To this end, the present application proposes a control method and device for starting a vehicle on a hill. In the scenario of starting on a hill, a slope compensation coefficient is calculated based on the real-time slope and the adhesion coefficient under the real-time weather conditions, and a final driving torque is calculated based on the slope compensation coefficient. The control method for driving the vehicle to start according to the final driving torque can not only avoid stagnation or even slipping to a certain extent, but also adapt to driving scenarios under various weather conditions, thereby improving the driving experience of users in the existing technology.

[0066] In one embodiment, Figure 1 As shown, a control method for starting a vehicle on a hill is provided. The method is described by taking the vehicle controller as an example, and includes the following steps:

[0067] S1: When it is recognized that the vehicle is currently on a slope and a start command is received, the current slope and the current adhesion coefficient under the current weather conditions are obtained.

[0068] It should be noted that the image information of the current road condition can be collected by an image acquisition device, and then based on the image processing technology, it can be determined whether the current vehicle is on a slope; it can also be determined by calculating the quotient of the elevation difference and the horizontal distance of a certain section of road, and then judging whether the current vehicle is on a slope based on the quotient. The starting instruction refers to an instruction to drive the current vehicle to start with the current driving torque, wherein the current driving torque is calculated based on the collected accelerator pedal opening depressed by the driver and the vehicle speed corresponding to the accelerator pedal opening. Through actual vehicle testing, the accelerator pedal opening is taken as 0, 5, 10, 20, 40, 70, 80 and 100 in sequence, and the following can be obtained: Figure 2 The relationship diagram of the accelerator pedal opening, the vehicle speed corresponding to the accelerator pedal opening and the current driving torque shown in FIG; Figure 2 It can be seen that at the same vehicle speed, the greater the accelerator pedal opening, the greater the corresponding current driving torque; when the accelerator pedal opening remains unchanged, the smaller the vehicle speed, the greater the corresponding current driving torque.

[0069] In a specific embodiment, the step of obtaining the current slope includes: collecting the longitudinal acceleration of the current vehicle in the direction of travel and the lateral acceleration horizontally perpendicular to the direction of travel; and obtaining the current slope based on the longitudinal acceleration and the lateral acceleration. The mathematical expression used to obtain the current slope based on the longitudinal acceleration and the lateral acceleration includes: θ = arctan [(a x -a y ) / g], in this mathematical expression, θ is the current slope, a x is the lateral acceleration, a y is the longitudinal acceleration, g is the acceleration due to gravity, and its value can be 9.8m / s 2 .

[0070] In another embodiment, the slope value and the confidence level corresponding to the slope value can also be obtained from the high-precision map. When the confidence level is 1, it means that the slope value corresponding to the confidence level is credible, and the slope value is used as the current slope. When the confidence level is 0, it means that the slope value corresponding to the confidence level is uncredible, and the current slope is determined by the above-mentioned calculation method based on the longitudinal acceleration and lateral acceleration.

[0071] Weather conditions can affect the adhesion coefficient between the vehicle and the road. For example, rainy or snowy weather can make the road slippery or even icy, which reduces the adhesion coefficient. Consequently, the friction during vehicle start-up decreases, requiring more driving force. Therefore, this application obtains the current adhesion coefficient under current weather conditions and re-determines the final driving torque based on the current adhesion coefficient and the current slope, thereby improving the problem of the vehicle stalling or even rolling when starting on a slope.

[0072] In a specific application scenario, if the current weather indication is sunny, cloudy or snowy, the step of obtaining the current adhesion coefficient under the current weather includes: collecting the current temperature under the current weather; obtaining a first mapping relationship between temperature and adhesion coefficient, and obtaining the current adhesion coefficient based on the current temperature and the first mapping relationship.

[0073] The step of obtaining a first mapping relationship between temperature and adhesion coefficient includes: obtaining a first test data set, wherein the first test data set includes multiple first data groups, each of the first data groups includes a first test temperature and a first test adhesion coefficient; and fitting the first test data set to obtain a first mapping relationship between the temperature and the adhesion coefficient.

[0074] It should be noted that on sunny, cloudy or snowy days, the adhesion coefficient between the vehicle and the road is mainly affected by temperature. Actual vehicle tests can be carried out on sunny, cloudy or snowy days at different temperatures to collect the current first test temperature and the first test adhesion coefficient between the test vehicle and the road. Through multiple actual vehicle tests, multiple groups of first data groups including the first test temperature and the first test adhesion coefficient are obtained. Then, data fitting is performed on the first test data set including all the first data groups to obtain a first mapping relationship.

[0075] For example, the first mapping relationship may include: when the current weather indication is sunny, if the current temperature is greater than 0°C, the current adhesion coefficient is 0.7; if the current temperature is less than -10°C, the current adhesion coefficient is 0.4; if the current temperature is less than or equal to 0°C and greater than or equal to -10°C, the current adhesion coefficient is between [0.4, 0.7]. In this case, the first mapping relationship can be expressed as K t =0.7+0.03t,K t is the current adhesion coefficient, and t is the current temperature. When the current weather indication is cloudy, if the current temperature is greater than -2°C, the current adhesion coefficient is 0.5; if the current temperature is less than -15°C, the current adhesion coefficient is 0.35; if the current temperature is less than or equal to -2°C and greater than or equal to -15°C, the current adhesion coefficient is between [0.35, 0.5]. In this case, the first mapping relationship can be expressed as K t =0.35+t*3 / 260+9 / 52, K t is the current adhesion coefficient, and t is the current temperature. If the current weather indication is snow, and the current temperature is greater than or equal to 0°C, the current adhesion coefficient is 0.45; if the current temperature is less than 0°C, the current adhesion coefficient is 0.4.

[0076] In another applicable scenario, if the current weather indication is rainy, the step of obtaining the current adhesion coefficient under the current weather includes: collecting the current temperature and current rainfall under the current weather; obtaining a second mapping relationship between temperature, rainfall and adhesion coefficient, and obtaining the current adhesion coefficient based on the current temperature, the current rainfall and the second mapping relationship.

[0077] The step of obtaining a second mapping relationship between temperature, rainfall, and adhesion coefficient includes: obtaining a second test data set, wherein the second test data set includes multiple second data groups, each second data group includes a second test temperature, a test rainfall, and a second test adhesion coefficient; fitting the second test data set to obtain a second mapping relationship between the temperature, the rainfall, and the adhesion coefficient.

[0078] It should be noted that on rainy days, the adhesion coefficient between the vehicle and the road is mainly affected by temperature and rainfall. Therefore, actual vehicle tests can be carried out on rainy days with different rainfall amounts to collect the current second test temperature, test rainfall, and the second test adhesion coefficient between the test vehicle and the road; through multiple actual vehicle tests, multiple groups of second data groups including the second test temperature, test rainfall and second test adhesion coefficient are obtained; then, data fitting is performed on the second test data set including all the second data groups to obtain a second mapping relationship.

[0079] For example, the second mapping relationship may include: when the current weather indicates rain and the current temperature is greater than -2°C, if the current rainfall indicates light rain, then the current adhesion coefficient is 0.5; if the current rainfall indicates moderate rain or heavy rain, then the current adhesion coefficient is 0.4; when the current temperature is less than or equal to -2°C, if the current rainfall indicates freezing rain, then the current adhesion coefficient is 0.35. The current weather can be identified as light rain, moderate rain, or heavy rain by setting a rainfall threshold and performing a threshold determination.

[0080] S2: Obtaining the minimum driving torque currently required by the vehicle according to the current slope and the current adhesion coefficient.

[0081] In a specific embodiment, the step of obtaining the minimum driving torque required for the current vehicle based on the current slope and the current adhesion coefficient includes: obtaining the total weight of the current vehicle, wherein the total weight includes the current vehicle's own weight and the weight of the user in the current vehicle; and obtaining the minimum driving torque based on the total weight, the current slope and the current adhesion coefficient.

[0082] The weight of the user in the current vehicle can be collected by a seat sensor. The step of obtaining the minimum driving torque according to the total weight, the current slope and the current adhesion coefficient comprises: calculating the friction force of the current vehicle according to the total weight, the current slope and the current adhesion coefficient, wherein according to Figure 3 The force decomposition diagram of the current vehicle on the slope is shown. The mathematical expression used to calculate the friction force includes: f = K t *G*g*cosθ, in this mathematical expression, f is the friction force, K t is the current adhesion coefficient, G is the total weight, and g is the acceleration due to gravity, which can be 9.8m / s 2 , θ is the current slope; based on the friction, total weight and current slope, the minimum driving torque of the current vehicle is calculated, wherein the mathematical expression used to calculate the minimum driving torque includes: F1=f+G*g*sinθ, in which F1 is the minimum driving torque, f is the friction, G is the total weight, and g is the acceleration due to gravity, which can be 9.8m / s 2 , θ is the current slope.

[0083] S3: When the current driving torque indicated by the starting instruction is less than the minimum driving torque, determine a current slope compensation coefficient.

[0084] In a specific embodiment, the step of determining the current slope compensation coefficient includes: obtaining a third mapping relationship between slope and slope compensation coefficient; obtaining an initial compensation coefficient based on the current slope and the third mapping relationship; obtaining a fourth mapping relationship between torque difference and slope compensation coefficient; obtaining a current torque difference based on the current driving torque and the minimum driving torque, and obtaining a dynamic compensation coefficient based on the current torque difference and the fourth mapping relationship; determining whether the initial compensation coefficient is greater than the dynamic compensation coefficient; if so, using the initial compensation coefficient as the current slope compensation coefficient; if not, using the dynamic compensation coefficient as the current slope compensation coefficient. Preferably, the slope compensation coefficient can also be determined based on vehicle speed. If the current vehicle speed exceeds a vehicle speed threshold, the slope compensation coefficient is determined to be 1, i.e., no torque compensation is performed. The vehicle speed threshold may be 6 km / h.

[0085] Furthermore, the step of obtaining a third mapping relationship between the slope and the slope compensation coefficient includes: obtaining a third test data set, wherein the third test data set includes multiple third data groups, each of the third data groups includes a test slope and a first test slope compensation coefficient; fitting the third test data set to obtain a third mapping relationship between the slope and the slope compensation coefficient.

[0086] It should be noted that actual vehicle tests can be carried out on slopes with different test slopes, with the purpose of preventing the vehicle from stagnating or slipping when starting, to obtain a corresponding first test slope compensation coefficient; through multiple actual vehicle tests, multiple sets of third data groups including test slopes and first test slope compensation coefficients are obtained; then, data fitting is performed on a third test data set including multiple sets of third data groups to obtain a third mapping relationship.

[0087] For example, the third mapping relationship may include: if the current slope is greater than 20%, the current slope compensation coefficient is 1.3; if the current slope is less than or equal to 20% and greater than or equal to 10%, the current slope compensation coefficient is 1.2; if the current slope is less than 10%, the current slope compensation coefficient is 1.0.

[0088] Furthermore, the step of obtaining a fourth mapping relationship between the torque difference and the slope compensation coefficient includes: obtaining a fourth test data set, wherein the fourth test data set includes multiple fourth data groups, each of the fourth data groups includes a test torque difference and a second test slope compensation coefficient; fitting the fourth test data set to obtain a fourth mapping relationship between the torque difference and the slope compensation coefficient.

[0089] It should be noted that in actual vehicle tests, the corresponding test driving torque can be calculated according to different accelerator pedal openings, and the test minimum driving torque can be calculated according to the steps of calculating the minimum driving torque mentioned above, and then the test torque difference can be obtained based on the test driving torque and the test minimum driving torque; the corresponding second test slope compensation coefficient is obtained based on the judgment condition that the driving torque can drive the vehicle to start normally; through multiple actual vehicle tests, multiple groups of fourth data groups including the test torque difference and the second test slope compensation coefficient are obtained; then the fourth test data set including multiple groups of fourth data groups is data fitted to obtain a fourth mapping relationship.

[0090] By way of example, the fourth mapping relationship may include: if the current torque difference is less than -500, the dynamic compensation coefficient is 1.7; if the current torque difference is [-500, 0], the dynamic compensation coefficient is [1.3, 1.6], and the fourth mapping relationship may be expressed as h2=Δh*3 / 500=1.6, where h2 is the dynamic compensation coefficient and Δh is the current torque difference; if the current torque difference is 0, the dynamic compensation coefficient is 1.3; if the current torque difference is [0, 200], the dynamic compensation coefficient is [1.3, 1.1], and the fourth mapping relationship may be expressed as h2=-0.001*Δh+1.3, where h2 is the dynamic compensation coefficient and Δh is the current torque difference; if the current torque difference is greater than 200, the dynamic compensation coefficient is 1.1.

[0091] S4: Determine a final driving torque based on the current slope compensation coefficient and the current driving torque, and control the vehicle to start based on the final driving torque. Determine the final driving torque based on the product of the current slope compensation coefficient and the current driving torque, and control the vehicle to start based on the final driving torque.

[0092] To sum up, in the scenario of starting on a slope, the present application can calculate the slope compensation coefficient based on the real-time slope and the adhesion coefficient under the real-time weather conditions, so that the final driving torque obtained according to the slope compensation coefficient can drive the vehicle to start. It can not only avoid the slipping phenomenon to a certain extent, but also be compatible with driving scenarios under various weather conditions, thereby improving the driving experience of users in the existing technology.

[0093] It should be understood that although Figure 1 The steps in the flowchart are shown in sequence as indicated by the arrows, but these steps are not necessarily executed in the order indicated by the arrows. Unless otherwise specified in this document, there is no strict order restriction for the execution of these steps, and these steps can be executed in other orders. In addition, Figure 1 At least part of the steps may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily executed at the same time, but can be executed at different times. The execution order of these sub-steps or stages is not necessarily sequential, but can be executed in turn or alternately with other steps or at least part of the sub-steps or stages of other steps.

[0094] In one embodiment, Figure 4 As shown, a control device for a vehicle starting on a hill is provided, comprising: a parameter acquisition module, a parameter processing module, a compensation coefficient determination module and a control module, wherein:

[0095] A parameter acquisition module, upon recognizing that the vehicle is currently on a slope and receiving a start command, acquires the current slope and the current adhesion coefficient under the current weather conditions;

[0096] a parameter processing module, which obtains the minimum driving torque required by the current vehicle according to the current slope and the current adhesion coefficient;

[0097] a compensation coefficient determining module, configured to determine a current slope compensation coefficient when the current driving torque indicated by the starting instruction is less than the minimum driving torque;

[0098] The control module obtains a final driving torque according to the current slope compensation coefficient and the current driving torque, and controls the current vehicle to start according to the final driving torque.

[0099] Specifically, such as Figure 5As shown, the parameter acquisition module includes a collection unit and a calculation unit, wherein the collection unit is electrically connected to the calculation unit, and the collection unit is used to collect the longitudinal acceleration of the current vehicle in the driving direction and the lateral acceleration horizontally perpendicular to the driving direction; the calculation unit is used to calculate the current slope based on the longitudinal acceleration and the lateral acceleration, wherein the mathematical expression for calculating the current slope includes: θ = arctan [(a x -a y ) / g], θ is the current slope, a x is the lateral acceleration, a y is the longitudinal acceleration, g is the acceleration due to gravity. For example, the acquisition unit may include a speed sensor.

[0100] Specifically, the acquisition unit is further configured to acquire the current temperature under the current weather conditions; the calculation unit is further configured to obtain a first mapping relationship between temperature and adhesion coefficient, and to obtain the current adhesion coefficient based on the current temperature and the first mapping relationship. By way of example, the acquisition unit may further include a temperature sensor. Alternatively, the acquisition unit may further include the current temperature and rainfall under the current weather conditions; the calculation unit may further obtain a second mapping relationship between temperature, rainfall, and adhesion coefficient, and to obtain the current adhesion coefficient based on the current temperature, the current rainfall, and the second mapping relationship. By way of example, the acquisition unit may further include a temperature sensor and a rainfall sensor.

[0101] Specifically, the calculation unit executes the step of obtaining a first mapping relationship between temperature and adhesion coefficient, including: obtaining a first test data set, wherein the first test data set includes multiple first data groups, each first data group includes a first test temperature and a first test adhesion coefficient; and fitting the first test data set to obtain the first mapping relationship between the temperature and the adhesion coefficient.

[0102] Specifically, the calculation unit executes the step of obtaining a second mapping relationship between temperature, rainfall, and adhesion coefficient, including: obtaining a second test data set, wherein the second test data set includes multiple second data groups, each second data group includes a second test temperature, a test rainfall, and a second test adhesion coefficient; fitting the second test data set to obtain a second mapping relationship between the temperature, the rainfall, and the adhesion coefficient.

[0103] Specifically, the parameter processing module performs the step of obtaining the minimum driving torque required by the current vehicle according to the current slope and the current adhesion coefficient, including: obtaining the total weight of the current vehicle, wherein the total weight includes the weight of the current vehicle itself and the weight of the user in the current vehicle; calculating the friction force according to the total weight, the current slope and the current adhesion coefficient, wherein the mathematical expression for calculating the friction force includes: f = K t *G*g*cosθ, f is the friction force, K t is the current adhesion coefficient, G is the total weight, g is the acceleration of gravity, and θ is the current slope; the minimum driving torque is calculated based on the friction force, the total weight, and the current slope, wherein the mathematical expression for calculating the minimum driving torque includes: F1=f+G*g*sinθ, where F1 is the minimum driving torque.

[0104] Specifically, the compensation coefficient determination module executes the steps of determining the current slope compensation coefficient, including: obtaining a third mapping relationship between the slope and the slope compensation coefficient; obtaining an initial compensation coefficient based on the current slope and the third mapping relationship; obtaining a fourth mapping relationship between the torque difference and the slope compensation coefficient; obtaining a current torque difference based on the current driving torque and the minimum driving torque, and obtaining a dynamic compensation coefficient based on the current torque difference and the fourth mapping relationship; judging whether the initial compensation coefficient is greater than the dynamic compensation coefficient; if so, using the initial compensation coefficient as the current slope compensation coefficient; if not, using the dynamic compensation coefficient as the current slope compensation coefficient.

[0105] Specifically, the compensation coefficient determination module executes the step of obtaining a third mapping relationship between the slope and the slope compensation coefficient, including: obtaining a third test data set, wherein the third test data set includes multiple third data groups, each of the third data groups includes a test slope and a first test slope compensation coefficient; fitting the third test data set to obtain a third mapping relationship between the slope and the slope compensation coefficient.

[0106] Specifically, the compensation coefficient determination module executes the step of obtaining a fourth mapping relationship between the torque difference and the slope compensation coefficient, including: obtaining a fourth test data set, wherein the fourth test data set includes multiple fourth data groups, each of the fourth data groups includes a test torque difference and a second test slope compensation coefficient; fitting the fourth test data set to obtain a fourth mapping relationship between the torque difference and the slope compensation coefficient.

[0107] The specific definitions of the vehicle hill start control device can be found in the definitions of the vehicle hill start control method described above and will not be repeated here. Each module in the aforementioned vehicle hill start control device can be implemented in whole or in part via software, hardware, or a combination thereof. Each of these modules can be embedded in or independent of a processor within a computer device in hardware form, or stored in a computer device memory in software form, allowing the processor to call and execute the corresponding operations of each module.

[0108] In another embodiment, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the following steps are implemented:

[0109] When the vehicle is identified as being on a slope and a start command is received, the current slope and the current adhesion coefficient under the current weather conditions are obtained;

[0110] obtaining a minimum driving torque currently required by the vehicle according to the current slope and the current adhesion coefficient;

[0111] determining a current slope compensation coefficient when the current driving torque indicated by the starting instruction is less than the minimum driving torque;

[0112] A final driving torque is obtained according to the current slope compensation coefficient and the current driving torque, and the current vehicle starting is controlled according to the final driving torque.

[0113] In one embodiment, when the computer program is executed by a processor, the following steps are further implemented:

[0114] Collecting the longitudinal acceleration of the current vehicle in the direction of travel and the lateral acceleration horizontally perpendicular to the direction of travel;

[0115] The current slope is calculated according to the longitudinal acceleration and the lateral acceleration, wherein the mathematical expression for calculating the current slope includes:

[0116] θ=arctan[(a x -a y ) / g]

[0117] θ is the current slope, a x is the lateral acceleration, a y is the longitudinal acceleration, and g is the acceleration due to gravity.

[0118] In one embodiment, when the computer program is executed by a processor, the following steps are further implemented:

[0119] Collect the current temperature under the current weather conditions;

[0120] Acquire a first mapping relationship between temperature and adhesion coefficient, and obtain the current adhesion coefficient according to the current temperature and the first mapping relationship; or,

[0121] Collect the current temperature and rainfall under the current weather conditions;

[0122] A second mapping relationship among temperature, rainfall, and adhesion coefficient is acquired, and the current adhesion coefficient is obtained according to the current temperature, the current rainfall, and the second mapping relationship.

[0123] In one embodiment, when the computer program is executed by a processor, the following steps are further implemented:

[0124] Acquire a first test data set, wherein the first test data set includes a plurality of first data groups, each of the first data groups includes a first test temperature and a first test adhesion coefficient;

[0125] The first test data set is fitted to obtain a first mapping relationship between the temperature and the adhesion coefficient.

[0126] In one embodiment, when the computer program is executed by a processor, the following steps are further implemented:

[0127] Acquire a second test data set, wherein the second test data set includes a plurality of second data groups, each of the second data groups includes a second test temperature, a test rainfall, and a second test adhesion coefficient;

[0128] The second test data set is fitted to obtain a second mapping relationship among the temperature, the rainfall, and the adhesion coefficient.

[0129] In one embodiment, when the computer program is executed by a processor, the following steps are further implemented:

[0130] Obtaining the total weight of the current vehicle, wherein the total weight includes the weight of the current vehicle itself and the weight of the user in the current vehicle;

[0131] Calculate friction force according to the total weight, the current slope, and the current adhesion coefficient, wherein the mathematical expression for calculating the friction force includes:

[0132] f=K t *G*g*cosθ

[0133] f is the friction force, K t is the current adhesion coefficient, G is the total weight, g is the acceleration due to gravity, and θ is the current slope;

[0134] The minimum driving torque is calculated according to the friction force, the total weight, and the current slope, wherein the mathematical expression for calculating the minimum driving torque includes:

[0135] F1=f+G*g*sinθ

[0136] F1 is the minimum driving torque.

[0137] In one embodiment, when the computer program is executed by a processor, the following steps are further implemented:

[0138] Obtaining a third mapping relationship between the slope and the slope compensation coefficient;

[0139] Obtaining an initial compensation coefficient according to the current slope and the third mapping relationship;

[0140] Obtaining a fourth mapping relationship between the torque difference and the slope compensation coefficient;

[0141] obtaining a current torque difference according to the current driving torque and the minimum driving torque, and obtaining a dynamic compensation coefficient according to the current torque difference and the fourth mapping relationship;

[0142] Determining whether the initial compensation coefficient is greater than the dynamic compensation coefficient;

[0143] If so, using the initial compensation coefficient as the current slope compensation coefficient;

[0144] If not, the dynamic compensation coefficient is used as the current slope compensation coefficient.

[0145] In one embodiment, when the computer program is executed by a processor, the following steps are further implemented:

[0146] Acquire a third test data set, wherein the third test data set includes a plurality of third data groups, each of the third data groups includes a test slope and a first test slope compensation coefficient;

[0147] The third test data set is fitted to obtain a third mapping relationship between the slope and the slope compensation coefficient.

[0148] In one embodiment, when the computer program is executed by a processor, the following steps are further implemented:

[0149] Acquire a fourth test data set, wherein the fourth test data set includes a plurality of fourth data groups, each of the fourth data groups includes a test torque difference value and a second test slope compensation coefficient;

[0150] Fitting the fourth test data set to obtain a fourth mapping relationship between the torque difference and the hill compensation coefficient. In one embodiment, a vehicle is provided, comprising the vehicle hill start control device as described in any one of the preceding embodiments, the vehicle hill start control device being configured to execute the steps of the vehicle hill start control method as described in any one of the preceding embodiments.

[0151] Those skilled in the art will appreciate that all or part of the processes in the above-mentioned embodiments can be implemented by instructing the relevant hardware through a computer program. The computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to memory, storage, database or other media used in the embodiments provided in this application can include non-volatile and / or volatile memory. Non-volatile memory can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM) or flash memory. Volatile memory can include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in various forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link (Synchlink) DRAM (SLDRAM), memory bus (Rambus) direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM).

[0152] The technical features of the above embodiments can be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0153] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art could make various modifications and improvements without departing from the spirit of the present application, all of which fall within the scope of protection of the present application. Therefore, the scope of protection of the present patent application shall be determined by the appended claims.

Claims

1. A method for controlling a vehicle starting on a hill, characterized in that: include: When the vehicle is identified as being on a slope and a start command is received, the current slope and the current adhesion coefficient under the current weather conditions are obtained; obtaining a minimum driving torque currently required by the vehicle according to the current slope and the current adhesion coefficient; When the current driving torque indicated by the starting instruction is less than the minimum driving torque, obtaining a third mapping relationship between the slope and the slope compensation coefficient; Obtaining an initial compensation coefficient according to the current slope and the third mapping relationship; Obtaining a fourth mapping relationship between the torque difference and the slope compensation coefficient; obtaining a current torque difference according to the current driving torque and the minimum driving torque, and obtaining a dynamic compensation coefficient according to the current torque difference and the fourth mapping relationship; Determining whether the initial compensation coefficient is greater than the dynamic compensation coefficient; If so, use the initial compensation coefficient as the current slope compensation coefficient; If not, using the dynamic compensation coefficient as the current slope compensation coefficient; A final driving torque is obtained according to the current slope compensation coefficient and the current driving torque, and the current vehicle starting is controlled according to the final driving torque.

2. The vehicle hill start control method according to claim 1, characterized in that: The steps to obtain the current slope include: Collecting the longitudinal acceleration of the current vehicle in the direction of travel and the lateral acceleration horizontally perpendicular to the direction of travel; The current slope is calculated according to the longitudinal acceleration and the lateral acceleration, wherein the mathematical expression for calculating the current slope includes: θ=arctan[(a x -a y ) / g] θ is the current slope, a x is the lateral acceleration, a y is the longitudinal acceleration, and g is the acceleration due to gravity.

3. The method for controlling a vehicle hill start according to claim 1, wherein: The steps for obtaining the current adhesion coefficient under the current weather conditions include: Collect the current temperature under the current weather conditions; Acquire a first mapping relationship between temperature and adhesion coefficient, and obtain the current adhesion coefficient according to the current temperature and the first mapping relationship; or, Collect the current temperature and rainfall under the current weather conditions; A second mapping relationship among temperature, rainfall, and adhesion coefficient is acquired, and the current adhesion coefficient is obtained according to the current temperature, the current rainfall, and the second mapping relationship.

4. The method for controlling a vehicle hill start according to claim 3, wherein: The step of obtaining a first mapping relationship between temperature and adhesion coefficient includes: Acquire a first test data set, wherein the first test data set includes a plurality of first data groups, each of the first data groups includes a first test temperature and a first test adhesion coefficient; The first test data set is fitted to obtain a first mapping relationship between the temperature and the adhesion coefficient.

5. The method for controlling a vehicle hill start according to claim 3, wherein: The step of obtaining a second mapping relationship between temperature, rainfall, and adhesion coefficient includes: Acquire a second test data set, wherein the second test data set includes a plurality of second data groups, each of the second data groups includes a second test temperature, a test rainfall, and a second test adhesion coefficient; The second test data set is fitted to obtain a second mapping relationship among the temperature, the rainfall, and the adhesion coefficient.

6. The method for controlling a vehicle hill start according to claim 1, wherein: The step of obtaining the minimum driving torque currently required by the vehicle according to the current slope and the current adhesion coefficient includes: Obtaining the total weight of the current vehicle, wherein the total weight includes the weight of the current vehicle itself and the weight of the user in the current vehicle; Calculate friction force according to the total weight, the current slope, and the current adhesion coefficient, wherein the mathematical expression for calculating the friction force includes: f=K t *G*g*cosθ f is the friction force, K t is the current adhesion coefficient, G is the total weight, g is the acceleration due to gravity, and θ is the current slope; The minimum driving torque is calculated according to the friction force, the total weight, and the current slope, wherein the mathematical expression for calculating the minimum driving torque includes: F1=f+G*g*sinθ F1 is the minimum driving torque.

7. The method for controlling a vehicle hill start according to claim 1, wherein: The step of obtaining a third mapping relationship between the slope and the slope compensation coefficient includes: Acquire a third test data set, wherein the third test data set includes a plurality of third data groups, each of the third data groups includes a test slope and a first test slope compensation coefficient; The third test data set is fitted to obtain a third mapping relationship between the slope and the slope compensation coefficient.

8. The method for controlling a vehicle hill start according to claim 1, wherein: The step of obtaining a fourth mapping relationship between the torque difference and the slope compensation coefficient includes: Acquire a fourth test data set, wherein the fourth test data set includes a plurality of fourth data groups, each of the fourth data groups includes a test torque difference value and a second test slope compensation coefficient; The fourth test data set is fitted to obtain a fourth mapping relationship between the torque difference and the slope compensation coefficient.

9. A control device for starting a vehicle on a hill, characterized in that: The device comprises: A parameter acquisition module, upon recognizing that the vehicle is currently on a slope and receiving a start command, acquires the current slope and the current adhesion coefficient under the current weather conditions; a parameter processing module, which obtains the minimum driving torque required by the current vehicle according to the current slope and the current adhesion coefficient; a compensation coefficient determination module, when the current driving torque indicated by the starting instruction is less than the minimum driving torque, obtaining a third mapping relationship between a slope and a slope compensation coefficient; obtaining an initial compensation coefficient based on the current slope and the third mapping relationship; obtaining a fourth mapping relationship between a torque difference and a slope compensation coefficient; obtaining a current torque difference based on the current driving torque and the minimum driving torque, and obtaining a dynamic compensation coefficient based on the current torque difference and the fourth mapping relationship; determining whether the initial compensation coefficient is greater than the dynamic compensation coefficient; if so, using the initial compensation coefficient as the current slope compensation coefficient; if not, using the dynamic compensation coefficient as the current slope compensation coefficient; The control module obtains a final driving torque according to the current slope compensation coefficient and the current driving torque, and controls the current vehicle to start according to the final driving torque.

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