CN117944654A

CN117944654A - Vehicle control method, controller, vehicle and readable storage medium

Info

Publication number: CN117944654A
Application number: CN202311763079.9A
Authority: CN
Inventors: 刘波; 李军
Original assignee: Chongqing Ruilan Automobile Research Institute Co ltd; Chongqing Ruilan Automotive Technology Co ltd; Zhejiang Geely Holding Group Co Ltd
Current assignee: Chongqing Ruilan Automobile Research Institute Co ltd; Chongqing Ruilan Automotive Technology Co ltd; Zhejiang Geely Holding Group Co Ltd
Priority date: 2023-12-20
Filing date: 2023-12-20
Publication date: 2024-04-30

Abstract

The application belongs to the technical field of vehicles, and relates to a vehicle control method, a controller, a vehicle and a readable storage medium. A vehicle control method comprising: s1: and acquiring the current slip rate and the current required torque. S2: when the traction control system is not activated, an engine target torque corresponding to an attachment coefficient of a current road is obtained in response to the current slip ratio being greater than or equal to a first slip ratio threshold. S3: in response to the current demand torque being greater than the engine target torque, a torque adjustment operation is performed based on the engine target torque. Therefore, the application can adjust the engine torque in advance by monitoring the increasing trend of the slip rate before the traction control system is activated, so as to avoid the situation that the slip rate of the tire exceeds the optimal slip rate range due to response delay after the subsequent traction control system is activated, thereby improving the driving experience of the vehicle.

Description

Vehicle control method, controller, vehicle and readable storage medium

Technical Field

The application relates to the technical field of vehicles, in particular to a vehicle control method, a controller, a vehicle and a readable storage medium.

Background

Along with the development of automobile industry, the acceleration performance of the automobile is more and more concerned, the output torque of the power assembly is also more and more large, so that the phenomenon of skidding of the tire occurs in the acceleration process, the acceleration performance is reduced, the service life of the tire is shortened, the use cost is increased, meanwhile, friction noise is generated, and the driving experience is reduced. Traction control systems are currently employed by the industry to address tire acceleration slip. The function is passive triggering, the slip rate of the driving wheel is monitored through a wheel speed signal, when the slip rate reaches a set threshold value, the function is activated, a torque reducing request is sent to an engine, and the slip rate of the tire is controlled in an optimal range, so that better acceleration performance is obtained.

However, due to the determination of the traction control system and the time required for the torque response of the engine, the engine torque continues to increase during this time, and the slip ratio of the tire may exceed the optimal slip ratio range before the traction control system is activated and a torque down request is made to the engine, resulting in reduced acceleration performance and friction noise. Therefore, how to avoid the situation that the response delay of the traction control system causes the slip ratio of the tire to exceed the optimal slip ratio range is a technical problem that needs to be solved by those skilled in the art.

Disclosure of Invention

In view of the above technical problems, the present application provides a vehicle control method, a controller, a vehicle and a readable storage medium, so as to adjust engine torque in advance by monitoring an increasing trend of a slip rate before a traction control system is activated, so as to avoid a situation that a response delay is caused after a subsequent traction control system is activated, and the slip rate of a tire exceeds an optimal slip rate range, thereby improving driving experience of the vehicle.

To solve the above technical problem, a first aspect of the present application provides a vehicle control method, including: s1: and acquiring the current slip rate and the current required torque. S2: when the traction control system is not activated, an engine target torque corresponding to an attachment coefficient of a current road is obtained in response to the current slip ratio being greater than or equal to a first slip ratio threshold. S3: in response to the current demand torque being greater than the engine target torque, a torque adjustment operation is performed based on the engine target torque.

Optionally, step S2 includes: and acquiring the road surface attachment rate under the current slip rate based on the vehicle condition information, wherein the vehicle condition information comprises vehicle structure information and vehicle running information. And acquiring the attachment coefficient of the current road based on the road surface attachment rate. The engine target torque is obtained based on the attachment coefficient.

Optionally, the step of acquiring the road surface adhesion rate at the current slip rate based on the vehicle condition information includes: based on the vehicle condition information, the road surface attachment rate is calculated by a road surface attachment rate calculation formula: wherein, the road surface adhesion rate formula: phi = Fxb/fz= (m x a)/(G (cosα x b2-sin α x hg)/L- (δ x m x a+ (C _D x a x u 2/21.15))xhg/L. Or, Φ=fxb/fz= (m×a)/(G (cosαb1+sinα×hg)/l+ (δ×m×a+ (C _D ×a×u2/21.15))×hg/L. Where phi represents the road surface adhesion rate, fxb represents the tangential reaction force of the road surface to the tire, and Fz represents the normal reaction force of the road surface to the tire. Wherein m represents the mass of the whole vehicle, a represents the longitudinal acceleration of the vehicle, G represents the gravity of the whole vehicle, alpha represents the included angle between the road surface and the horizontal, u represents the vehicle speed, b1 represents the distance from the mass center to the front axle, b2 represents the distance from the mass center to the rear axle, hg represents the distance from the mass center of the whole vehicle to the road surface, C _D represents the wind resistance coefficient, A represents the windward area, L represents the wheelbase, and delta represents the rotational mass conversion coefficient.

Optionally, the step of obtaining the engine target torque based on the attachment coefficient includes: the vehicle target acceleration is acquired based on the attachment coefficient. And acquiring the target torque of the engine through an engine torque calculation formula based on the acceleration and the power influence factors. Wherein, the engine torque calculation formula ：T_tq＝(F_f+F_w+F_i+F_j)*r/(i_g*i₀*i_q*η_t)＝(G*f*cosα+C_D*A*u2/21.15+G*sinα+δ*m*a₀)*r/(i_g*i₀*i_q*η_t). wherein T _tq represents the engine output torque, F _f represents the rolling resistance, F _w represents the air resistance, F _i represents the ramp resistance, F _j represents the acceleration resistance, F represents the rolling resistance coefficient, i _g represents the transmission gear ratio, i ₀ represents the final drive gear ratio, i _q represents the clutch engagement ratio, η _t represents the mechanical transmission efficiency, r represents the wheel rolling radius, a ₀ represents the vehicle target acceleration.

Optionally, step S3 includes: a torque limiting request is issued based on the engine target torque to control the engine trim torque. And updating the torque limiting request according to a preset period until the traction control system is activated.

Optionally, the first aspect of the present application provides a vehicle control method further comprising: and when the current slip rate is greater than or equal to a second slip rate threshold, activating the traction control system, wherein the second slip rate threshold is greater than the first slip rate threshold.

Optionally, before the step S3, the method includes: and responding to the road condition detection, and acquiring the minimum driving torque corresponding to the road condition detection result when the road condition detection result corresponds to the road condition of the ramp. Wherein performing a torque adjustment operation based on the engine target torque includes: and when the target torque of the engine is smaller than the minimum driving torque, performing torque reduction control with the minimum driving torque. Or, when the engine target torque is not less than the minimum drive torque, performing torque reduction control with the engine target torque.

A second aspect of the present application provides a controller comprising: a memory, a processor, wherein the memory stores a computer program which when executed by the processor implements the vehicle control method according to any one of the above.

A third aspect of the application provides a vehicle fitted with a controller as above.

A fourth aspect of the present application provides a readable storage medium having stored thereon a computer program which, when executed by a processor, implements a vehicle control method as any one of the above.

The application provides a vehicle control method, a controller, a vehicle and a readable storage medium. A vehicle control method comprising: s1: and acquiring the current slip rate and the current required torque. S2: when the traction control system is not activated, an engine target torque corresponding to an attachment coefficient of a current road is obtained in response to the current slip ratio being greater than or equal to a first slip ratio threshold. S3: in response to the current demand torque being greater than the engine target torque, a torque adjustment operation is performed based on the engine target torque. Therefore, the application can adjust the engine torque in advance by monitoring the increasing trend of the slip rate before the traction control system is activated, so as to avoid the situation that the slip rate of the tire exceeds the optimal slip rate range due to response delay after the subsequent traction control system is activated, thereby improving the driving experience of the vehicle.

Further, according to the road surface adhesion rate formula, a large amount of vehicle structure information and vehicle running information can be comprehensively considered to obtain the accurate road surface adhesion rate, so that the adhesion coefficient of the current road corresponding to the road surface adhesion rate can be further obtained. And then, the maximum tangential acting force and the longitudinal acceleration of the vehicle which can be provided by the road surface when the optimal slip rate is obtained based on the attachment coefficient of the current road, so that the target torque of the engine can be accurately calculated later, and proper torque reduction selection is provided.

Further, according to the application, through the engine torque calculation formula, a large number of power influence factors and the vehicle longitudinal acceleration corresponding to the current road optimal slip rate can be comprehensively considered, and the engine target torque is obtained, so that when the torque reduction control is performed based on the engine target torque, the vehicle can be accurately controlled within the optimal slip rate during running, and the vehicle has good kinetic energy performance, and the driving use experience is improved.

Further, the application can comprehensively consider the optimal slip rate and the minimum power requirement of the ramp by monitoring the increasing trend of the slip rate before the traction control system is activated, and perform proper torque reduction control on the engine so as to ensure the power of the uphill and avoid the vehicle from exceeding the optimal slip rate.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the application and together with the description, serve to explain the principles of the application. In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are needed in the description of the embodiments will be briefly described below, and it will be obvious to those skilled in the art that other drawings can be obtained from these drawings without inventive effort.

Fig. 1 is a schematic flow chart of a vehicle control method according to a first embodiment of the present application;

FIG. 2 is a flow chart of another vehicle control method according to the first embodiment of the application;

fig. 3 is a schematic structural view of a controller according to a second embodiment of the present application.

The achievement of the objects, functional features and advantages of the present application will be further described with reference to the accompanying drawings, in conjunction with the embodiments. Specific embodiments of the present application have been shown by way of the above drawings and will be described in more detail below. The drawings and the written description are not intended to limit the scope of the inventive concepts in any way, but rather to illustrate the inventive concepts to those skilled in the art by reference to the specific embodiments.

Detailed Description

Reference will now be made in detail to exemplary embodiments, examples of which are illustrated in the accompanying drawings. When the following description refers to the accompanying drawings, the same numbers in different drawings refer to the same or similar elements, unless otherwise indicated. The implementations described in the following exemplary examples do not represent all implementations consistent with the application. Rather, they are merely examples of apparatus and methods consistent with aspects of the application as detailed in the accompanying claims.

It should be noted that, in this document, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, the element(s) defined by the phrase "comprising one … …" does not exclude the presence of additional identical elements in a process, method, article, or apparatus that comprises the element(s), alternatively, elements, features, or elements having the same name in different embodiments of the application may have the same meaning or may have different meanings, a particular meaning of which is to be determined by its interpretation in this particular embodiment or by further context of this particular embodiment.

It should be understood that although the terms first, second, third, etc. may be used herein to describe various information, these information should not be limited by these terms. These terms are only used to distinguish one type of information from another. For example, first information may also be referred to as second information, and similarly, second information may also be referred to as first information, without departing from the scope herein. The word "if" as used herein may be interpreted as "at … …" or "at … …" or "in response to a determination" depending on the context. Furthermore, as used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context indicates otherwise. It will be further understood that the terms "comprises," "comprising," "includes," and/or "including" specify the presence of stated features, steps, operations, elements, components, items, categories, and/or groups, but do not preclude the presence, presence or addition of one or more other features, steps, operations, elements, components, items, categories, and/or groups. The terms "or" and/or "as used herein are to be construed as inclusive, or meaning any one or any combination. Thus, "A, B or C" or "A, B and/or C" means "any of the following: a, A is as follows; b, a step of preparing a composite material; c, performing operation; a and B; a and C; b and C; A. b and C). An exception to this definition will occur only when a combination of elements, functions, steps or operations are in some way inherently mutually exclusive.

It should be understood that, although the steps in the flowcharts in the embodiments of the present application are shown in order as indicated by the arrows, these steps are not necessarily performed in order as indicated by the arrows. The steps are not strictly limited in order and may be performed in other orders, unless explicitly stated herein. Moreover, at least some of the steps in the figures may include multiple sub-steps or stages that are not necessarily performed at the same time, but may be performed at different times, the order of their execution not necessarily occurring in sequence, but may be performed alternately or alternately with other steps or at least a portion of the other steps or stages.

It should be noted that, in this document, step numbers such as S1 and S2 are adopted, and the purpose of the present application is to more clearly and briefly describe the corresponding content, and not to constitute a substantial limitation on the sequence, and those skilled in the art may execute S2 first and then execute S1 when implementing the present application, which is within the scope of protection of the present application.

It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the application.

In the following description, suffixes such as "module", "part" or "unit" for representing elements are used only for facilitating the description of the present application, and have no specific meaning per se. Thus, "module," "component," or "unit" may be used in combination.

First embodiment

Fig. 1 is a schematic flow chart of a vehicle control method according to a first embodiment of the present application; FIG. 2 is a flow chart of another vehicle control method according to the first embodiment of the application;

For a clear description of the vehicle control method provided by the first embodiment of the application, reference may be made to fig. 1 and 2.

Referring to fig. 1, a vehicle control method provided in a first embodiment of the present application includes:

S1: and acquiring the current slip rate and the current required torque.

In one embodiment, slip ratio is the proportion of slip composition during wheel movement.

In one embodiment, in step S1: the obtaining the current slip rate and the current required torque may include: and acquiring the slip rate during acceleration based on the wheel speed of the driving wheel and the wheel speed of the driven wheel. Optionally, the slip rate may be obtained by searching slip rates corresponding to the wheel speed of the driving wheel and the wheel speed of the driven wheel from a pre-stored slip rate relation, or may be obtained by calculating through a slip rate calculation formula based on the wheel speed of the driving wheel and the wheel speed of the driven wheel.

In an embodiment, the current slip ratio is calculated by a slip ratio calculation formula based on the driving wheel speed and the driven wheel speed, optionally the slip ratio calculation formula: s= (u _q-u_c)/u_q, where u _q represents the current driving wheel speed and u _c represents the current driven wheel speed.

In one embodiment, the current demand torque may be a driver demand torque determined based on an accelerator opening value and a current vehicle speed, or may be a driver demand torque determined by other prior art means. For example, based on the accelerator pedal opening value and the current vehicle speed, preset query preset demand torque relationship information (demand torque relationship information includes the accelerator pedal opening value and the map between the vehicle speed and the demand torque) is queried to acquire the current demand torque.

S2: when the traction control system is not activated, an engine target torque corresponding to an attachment coefficient of a current road is obtained in response to the current slip ratio being greater than or equal to a first slip ratio threshold.

In an embodiment, the vehicle control method provided in the first embodiment of the present application may further include: and activating the traction control system when the current slip rate is greater than or equal to a second slip rate threshold, wherein the second slip rate threshold is greater than the first slip rate threshold. And closing the traction control system when the current slip ratio is less than a third slip ratio threshold, wherein the third slip ratio threshold may be the same as or different from the second slip ratio threshold.

In an embodiment, the first slip ratio threshold and the second slip ratio threshold may be two independent thresholds set according to an experimental test, or may be two values in a preset difference relationship or a preset ratio relationship. Alternatively, the first slip ratio threshold may be set at an interval of 5% to 15% (e.g., 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%). Alternatively, the second slip ratio threshold may be set at a range of 10% to 30% (10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 29%, 30%).

In one embodiment, at S2: the step of obtaining the engine target torque corresponding to the attachment coefficient of the current road in response to the current slip ratio being greater than or equal to the first slip ratio threshold value when the traction control system is not activated may include: and when the current slip rate is smaller than the second slip rate threshold value, judging that the traction control system is not activated. And obtaining an engine target torque corresponding to an attachment coefficient of the current road in response to the current slip ratio being greater than or equal to the first slip ratio threshold. Or in response to the current slip ratio being greater than or equal to the first slip ratio threshold and less than the second slip ratio threshold, obtaining an engine target torque corresponding to an attachment coefficient of the current road.

In other embodiments, the traction control system may also be activated when the throttle input data and engine torque do not match the road conditions.

In one embodiment, a traction control system (Traction Control System, abbreviated TCS, also known as ASR or TRC) is provided to prevent the driven wheel from losing traction and to prevent excessive tire slip during high acceleration/low traction conditions.

In one embodiment, step S2 includes: and acquiring the road surface attachment rate under the current slip rate based on the vehicle condition information, wherein the vehicle condition information comprises vehicle structure information and vehicle running information. And acquiring the attachment coefficient of the current road based on the road surface attachment rate. The engine target torque is obtained based on the attachment coefficient.

In one embodiment, the vehicle structural information includes at least one parameter related to structural components, such as wheelbase, frontal area, and the like.

In one embodiment, the vehicle driving information includes parameters of at least one vehicle in use, such as longitudinal acceleration, vehicle speed, road surface and horizontal angle, distance from center of mass to front axle, distance from center of mass to rear axle, distance from center of mass to road surface, mass of whole vehicle, and gravity of whole vehicle.

In one embodiment, the step of acquiring the road surface adhesion rate at the current slip rate based on the vehicle condition information includes: based on the vehicle condition information, the road surface attachment rate is calculated by a road surface attachment rate calculation formula: the road surface attachment rate calculation formula is a first road surface attachment rate calculation formula corresponding to front wheel driving or a second road surface attachment rate calculation formula corresponding to rear wheel driving;

In one embodiment, a first road surface attachment rate calculation formula corresponding to front wheel driving is as follows:

φ＝Fxb/Fz＝(m*a)/(G*(cosα*b2-sinα*hg)/L-(δ*m*a+(C_D*A*u2/21.15))*hg/L)

Where phi represents the road surface adhesion rate, fxb represents the tangential reaction force of the road surface to the tire, and Fz represents the normal reaction force of the road surface to the tire. Wherein m represents the mass of the whole vehicle, a represents the longitudinal acceleration of the vehicle, G represents the gravity of the whole vehicle, alpha represents the included angle between the road surface and the horizontal, u represents the vehicle speed, b2 represents the distance from the mass center to the rear axle, hg represents the distance from the mass center of the whole vehicle to the road surface, C _D represents the wind resistance coefficient, A represents the windward area, L represents the wheelbase, and delta represents the rotational mass conversion coefficient.

In one embodiment, the second road surface adhesion rate calculation formula corresponding to the rear wheel drive is as follows:

φ＝Fxb/Fz＝(m*a)/(G*(cosα*b1+sinα*hg)/L+(δ*m*a+(C_D*A*u2/21.15))*hg/L)

where phi represents the road surface adhesion rate, fxb represents the tangential reaction force of the road surface to the tire, and Fz represents the normal reaction force of the road surface to the tire. Wherein m represents the mass of the whole vehicle, a represents the longitudinal acceleration of the vehicle, G represents the gravity of the whole vehicle, alpha represents the included angle between the road surface and the horizontal, u represents the vehicle speed, b1 represents the distance from the mass center to the front axle, hg represents the distance from the mass center of the whole vehicle to the road surface, C _D represents the wind resistance coefficient, A represents the windward area, L represents the wheelbase, and delta represents the rotational mass conversion coefficient.

In an embodiment, the present embodiment can comprehensively consider a large amount of vehicle structure information and vehicle driving information through a road surface adhesion rate formula to obtain an accurate road surface adhesion rate, so as to further obtain an adhesion coefficient of a current road corresponding to the road surface adhesion rate. And then, the maximum tangential acting force and the longitudinal acceleration of the vehicle which can be provided by the road surface when the optimal slip rate is obtained based on the attachment coefficient of the current road, so that the target torque of the engine can be accurately calculated later, and proper torque reduction selection is provided.

In one embodiment, the step of obtaining the adhesion coefficient of the current road based on the road surface adhesion rate may include: and searching a corresponding attachment coefficient from preset attachment coefficient information based on the road surface attachment rate to serve as the attachment coefficient of the current road, wherein the attachment coefficient information comprises the corresponding relation between the road surface attachment rate and the attachment coefficient.

In an embodiment, the step of obtaining the engine target torque based on the attachment coefficient may be searching for a corresponding torque from preset torque relation information based on the attachment coefficient to be used as the engine target torque, and the torque relation information may include a correspondence between the attachment coefficient and the torque; further, the calculation may be performed in accordance with a preset calculation rule based on the attachment coefficient to obtain the engine target torque (for example, the vehicle target acceleration is obtained by an acceleration calculation formula based on the attachment coefficient; the engine target torque is obtained by an engine torque calculation formula based on the vehicle target acceleration). Alternatively, the engine target torque corresponds to an optimal slip ratio at the current adhesion parameter.

In one embodiment, the step of obtaining the engine target torque based on the attachment coefficient may include: the vehicle target acceleration is acquired based on the attachment coefficient. And acquiring the target torque of the engine through an engine torque calculation formula based on the acceleration and the power influence factors.

In one embodiment, the power influencing factors include at least one parameter related to power calculation, such as rolling resistance coefficient, transmission gear ratio, final drive gear ratio, clutch engagement ratio, mechanical transmission efficiency, wheel rolling radius, vehicle driving information (e.g. vehicle gravity, vehicle mass, frontal area, road surface and horizontal angle, wind resistance coefficient, vehicle speed, etc.).

In one embodiment, the engine torque calculation formula ：T_tq＝(F_f+F_w+F_i+F_j)*r/(i_g*i₀*i_q*η_t)＝(G*f*cosα+C_D*A*u2/21.15+G*sinα+δ*m*a₀)*r/(i_g*i₀*i_q*η_t). wherein T _tq represents the engine target torque, F _f represents the rolling resistance, F _w represents the air resistance, F _i represents the ramp resistance, F _j represents the acceleration resistance, F represents the rolling resistance coefficient, i _g represents the transmission gear ratio, i ₀ represents the final drive gear ratio, i _q represents the clutch engagement ratio, η _t represents the mechanical transmission efficiency, r represents the wheel rolling radius, a ₀ represents the vehicle target acceleration.

In one embodiment, the engine torque calculation formula is obtained by combining and deforming the driving force formula of the first wheel end and the driving force formula of the second wheel end.

Wherein, the driving force formula of first wheel end: f _t＝F_f+F_w+F_i+F_j; the driving force formula of the second wheel end: f _t＝T_tq*i_g*i₀*i_q*η_t/r; wherein F _t denotes a driving force output from the engine to the wheel end.

Therefore, according to the embodiment, through the engine torque calculation formula, a large number of power influence factors and the vehicle longitudinal acceleration corresponding to the current road optimal slip rate can be comprehensively considered, and the engine target torque is obtained, so that when the torque reduction control is performed based on the engine target torque, the vehicle can be accurately controlled to run within the optimal slip rate, good kinetic energy performance is achieved, and the driving use experience is improved.

In an embodiment, the step of acquiring the vehicle target acceleration based on the attachment coefficient may include: and acquiring the target acceleration of the vehicle based on the attachment coefficient and preset acceleration relation information, wherein the acceleration relation information comprises the corresponding relation between the attachment coefficient and the acceleration. Or acquiring the target acceleration of the vehicle through an acceleration calculation formula based on the attachment coefficient.

In one embodiment, the acceleration calculation formula:

a₀＝Fxb'/m＝(φ₀*Fz)/m

Where a ₀ denotes the vehicle target acceleration, fxb' denotes the maximum tangential reaction force at the adhesion coefficient phi ₀, m denotes the mass of the whole vehicle, and phi ₀ denotes the adhesion coefficient.

S3: in response to the current demand torque being greater than the engine target torque, a torque adjustment operation is performed based on the engine target torque.

In an embodiment, based on that the current slip rate is greater than or equal to the first slip rate threshold value and the current required torque is greater than the target torque of the engine, the slip rate increasing trend can be further accurately judged, so that the torque reducing control can be accurately performed in advance, the problem that the vehicle runs beyond the optimal slip rate due to too fast increase of the slip rate and response delay of a traction control system is avoided, and the driving experience is improved.

In one embodiment, step S3 includes: a torque limiting request is issued based on the engine target torque to control the engine trim torque. And updating the torque limiting request according to a preset period until the traction control system is activated.

In one embodiment, the torque limiting request is updated according to a preset period until the traction control system is activated, for example, the step S1 is returned according to the preset period: and acquiring the current slip rate and the current required torque. The preset period may be 5ms to 15ms, for example, 5ms, 6ms, 7ms, 8ms, 9ms, 10ms, 11ms, 12ms, 13ms, 14ms, 15ms, etc. Preferably, the cycle is 10ms in period, which can save the calculation force and ensure that the vehicle can not run beyond the optimal slip rate.

Referring to fig. 2, based on the technical concept of the above technical solution, the following example is a vehicle control method:

s11: if the current slip rate is monitored to be more than 5%, executing step S12;

S12: judging whether to activate a traction control system based on the current slip rate; if yes, executing step S13, namely activating a traction control system; if not, executing step S14;

in one embodiment, S12: based on the current slip ratio, determining whether to activate the traction control system, including: and judging whether the current slip rate is larger than or equal to the first slip rate threshold value and smaller than the second slip rate threshold value. Wherein the second slip ratio threshold is an activation threshold that activates the traction control system.

S14: acquiring an adhesion coefficient with a current road;

In one embodiment, S14: the step of obtaining the adhesion coefficient with the current road comprises the following steps: the road surface attachment rate is calculated by a road surface attachment rate calculation formula based on the vehicle condition information. And searching a corresponding attachment coefficient from preset attachment coefficient information based on the road surface attachment rate to serve as the attachment coefficient of the current road, wherein the attachment coefficient information comprises the corresponding relation between the road surface attachment rate and the attachment coefficient.

In one embodiment, the vehicle condition information includes vehicle structure information and vehicle travel information. The vehicle structural information includes at least one parameter related to structural components, such as wheelbase, frontal area, etc. The vehicle running information comprises parameters of at least one vehicle in the use process, such as longitudinal acceleration of the vehicle, speed of the vehicle, included angle between the road surface and the horizontal, distance between the mass center and the front shaft, distance between the mass center and the rear shaft, distance between the mass center of the whole vehicle and the road surface, mass of the whole vehicle, gravity of the whole vehicle and the like.

In an embodiment, the road surface attachment rate calculation formula is a first road surface attachment rate calculation formula corresponding to front wheel driving or a second road surface attachment rate calculation formula corresponding to rear wheel driving;

the first road surface attachment rate calculation formula corresponding to the front wheel driving comprises the following steps:

φ＝Fxb/Fz＝(m*a)/(G*(cosα*b2-sinα*hg)/L-(δ*m*a+(C_D*A*u2/21.15))*hg/L)

The second road surface adhesion rate calculation formula corresponding to the rear wheel drive comprises the following formula:

φ＝Fxb/Fz＝(m*a)/(G*(cosα*b1+sinα*hg)/L+(δ*m*a+(C_D*A*u2/21.15))*hg/L)

In an embodiment, the corresponding attachment coefficient may be found from the preset attachment coefficient information based on the road surface attachment rate to be used as the attachment coefficient of the current road, for example, the corresponding attachment coefficient may be found from the preset attachment coefficient information based on the road surface attachment rate phi to be used as the attachment coefficient phi ₀ of the current road.

S15: calculating an engine target torque based on the attachment coefficient;

in one embodiment, S15: the step of calculating the engine target torque based on the attachment coefficient may include: and acquiring the target acceleration of the vehicle through an acceleration calculation formula based on the attachment coefficient. And acquiring the target torque of the engine through an engine torque calculation formula based on the acceleration and the power influence factors.

In one embodiment, the step of obtaining the vehicle target acceleration through an acceleration calculation formula based on the attachment coefficient includes: calculating the maximum tangential reaction force which can be provided by the road surface when the optimal slip rate is calculated by a road surface tangential force calculation formula based on the attachment coefficient; the vehicle target acceleration is calculated by an acceleration calculation formula based on the maximum tangential reaction force.

Wherein, the formula is calculated to road surface tangential force:

fxb '=Φ ₀ ×fz, where Φ ₀ denotes the adhesion coefficient, fz denotes the normal reaction force of the road surface to the tire, and Fxb' denotes the maximum tangential reaction force.

Wherein, the acceleration calculation formula:

a ₀ =fxb '/m, where a ₀ represents the vehicle target acceleration, fxb' represents the maximum tangential reaction force at the attachment coefficient Φ ₀, and m represents the vehicle mass.

In one embodiment, the engine torque calculation formula is used for obtaining the engine target torque based on the acceleration and the power influence factors:

T_tq＝(F_f+F_w+F_i+F_j)*r/(i_g*i₀*i_q*η_t)＝(G*f*cosα+C_D*A*u2/21.15+G*sinα+δ*m*a₀)*r/(i_g*i₀*i_q*η_t)

Wherein T _tq denotes an engine target torque, F _f denotes a rolling resistance, F _w denotes an air resistance, F _i denotes a hill resistance, F _j denotes an acceleration resistance, F denotes a rolling resistance coefficient, i _g denotes a transmission gear ratio, i ₀ denotes a final drive gear ratio, i _q denotes a clutch engagement ratio, η _t denotes a mechanical transmission efficiency, r denotes a wheel rolling radius, a ₀ denotes a vehicle target acceleration.

S16: acquiring the current required torque, and judging whether the target torque of the engine is smaller than the current required torque; if yes, go to step S17; if not, returning to the step S12;

in one embodiment, the current demand torque is a driver demand torque.

And S17, requesting the engine management system to reduce the torque based on the target torque of the engine, and returning to the step S12.

Therefore, according to the vehicle control method of the embodiment, the engine torque can be adjusted in advance by monitoring the increasing trend of the slip rate before the traction control system is activated, so that the situation that the slip rate of the tire exceeds the optimal slip rate range due to response delay after the subsequent traction control system is activated is avoided, and the driving experience of the vehicle is improved. When the engine torque is adjusted, a large amount of power influence factors, vehicle structure information and the like can be comprehensively considered to obtain the engine target torque through a road surface adhesion rate formula and an engine torque calculation formula, so that when the torque reduction control is performed based on the engine target torque, the vehicle can be accurately controlled to run in the optimal slip rate, good kinetic energy performance is achieved, and driving use experience is improved.

In one embodiment, S3: in response to the current demand torque being greater than the engine target torque, prior to the torque adjustment operating step based on the engine target torque, may include: and responding to the road condition detection, and acquiring the minimum driving torque corresponding to the road condition detection result when the road condition detection result corresponds to the road condition of the ramp. Wherein performing a torque adjustment operation based on the engine target torque includes: and when the target torque of the engine is smaller than the minimum driving torque, performing torque reduction control with the minimum driving torque. Or, when the engine target torque is not less than the minimum drive torque, performing torque reduction control with the engine target torque. Therefore, the embodiment can comprehensively consider the optimal slip rate and the minimum power requirement of the ramp by monitoring the increasing trend of the slip rate before the traction control system is activated, and perform proper torque reduction control on the engine so as to ensure the power of the uphill and avoid the vehicle from exceeding the optimal slip rate.

In an embodiment, the condition of road condition detection may include: detecting a vehicle running state parameter to obtain a road condition detection result comprising road condition information based on the vehicle running state parameter, wherein the vehicle running state parameter comprises vehicle running information and running road information; for example, if the longitudinal acceleration of the vehicle in the vehicle running information is greater than a speed threshold (in an acceleration advancing state), and the gradient in the running road information is greater than a gradient threshold, a detection result including the road condition of the gradient is obtained; furthermore, it may further include: and acquiring current road condition information in the navigation information so as to acquire a detection result comprising the road condition of the ramp based on the current road condition information.

In one embodiment, the minimum drive torque may be the minimum value of the vehicle to overcome the ramp resistance (including roll resistance/windage, etc.).

In an embodiment, when the road condition detection result corresponds to a road condition of a slope, the step of obtaining the minimum driving torque corresponding to the road condition detection result may include: according to the gradient value and the whole vehicle mass, calculating to obtain a gravity component of the vehicle at the current position along the gradient direction, and acquiring a minimum driving force based on the gravity component (for example, taking the gravity component as the minimum driving force, and acquiring the minimum driving force based on the gravity component and a preset road condition correction coefficient); the minimum driving torque is obtained based on the minimum driving force.

In other embodiments, when the road condition detection result corresponds to a road condition of a slope, the step of obtaining the minimum driving torque corresponding to the road condition detection result may include: and searching corresponding minimum driving torque from preset minimum driving torque relation information according to the ramp value and the vehicle running information, wherein the minimum driving torque relation information comprises the corresponding relation between the ramp value and the vehicle running information and the driving torque. For example, according to the ramp value and the current number of vehicles, the corresponding minimum driving torque is searched from the preset minimum driving torque relation information.

A first embodiment of the present application provides a vehicle control method, including: s1: and acquiring the current slip rate and the current required torque. S2: when the traction control system is not activated, an engine target torque corresponding to an attachment coefficient of a current road is obtained in response to the current slip ratio being greater than or equal to a first slip ratio threshold. S3: in response to the current demand torque being greater than the engine target torque, a torque adjustment operation is performed based on the engine target torque. Therefore, the embodiment can adjust the engine torque in advance by monitoring the increasing trend of the slip rate before the traction control system is activated, so as to avoid the situation that the slip rate of the tire exceeds the optimal slip rate range due to response delay after the subsequent traction control system is activated, and further improve the driving experience of the vehicle.

Second embodiment:

Fig. 3 is a schematic structural diagram of a controller according to a second embodiment of the present application. For a clear description of the controller 1 provided in the second embodiment of the present application, please refer to fig. 3.

A second embodiment of the present application provides a controller 1, including: the processor a101 and the memory a201, optionally, the processor a101 is configured to execute a computer program A6 stored in the memory a201 to implement the steps of the vehicle control method as described in the first embodiment.

Alternatively, the controller 1 provided in this embodiment may include at least one processor a101 and at least one memory a201. Alternatively, the at least one processor a101 may be referred to as a processing unit A1, and the at least one memory a201 may be referred to as a storage unit A2. Alternatively, the storage unit A2 stores a computer program A6, which when executed by the processing unit A1, causes the controller 1 provided in the present embodiment to implement the steps of the vehicle control method as described in the first embodiment, for example, step S1 shown in fig. 1: acquiring a current slip rate and a current required torque; s2: when the traction control system is not activated, responding to the fact that the current slip rate is larger than or equal to a first slip rate threshold value, and acquiring an engine target torque corresponding to an attachment coefficient of a current road; s3: in response to the current demand torque being greater than the engine target torque, a torque adjustment operation is performed based on the engine target torque. Or, for example, the steps shown in fig. 2.

Alternatively, the controller 1 provided in the present embodiment may include a plurality of memories a201 (simply referred to as a storage unit A2).

Alternatively, the storage unit A2 may be a volatile memory or a nonvolatile memory, and may include both volatile and nonvolatile memories. Alternatively, the nonvolatile Memory may be a Read Only Memory (ROM), a programmable Read Only Memory (PROM, programmable Read-Only Memory), an erasable programmable Read Only Memory (EPROM, erasable Programmable Read-Only Memory), an electrically erasable programmable Read Only Memory (EEPROM, ELECTRICALLY ERASABLE PROGRAMMABLE READ-Only Memory), a magnetic random access Memory (FRAM, ferromagnetic random access Memory), a Flash Memory (Flash Memory), a magnetic surface Memory, an optical disk, or a compact disk-Only Memory (CD-ROM, compact Disc Read-Only Memory); the magnetic surface memory may be a disk memory or a tape memory. The volatile memory may be random access memory (RAM, random Access Memory) which acts as external cache memory. By way of example, and not limitation, many forms of RAM are available, such as static random access memory (SRAM, static Random Access Memory), synchronous static random access memory (SSRAM, synchronous Static Random Access Memory), dynamic random access memory (DRAM, dynamic Random Access Memory), synchronous dynamic random access memory (SDRAM, synchronous Dynamic Random Access Memory), double data rate synchronous dynamic random access memory (ddr SDRAM, double Data Rate Synchronous Dynamic Random Access Memory), enhanced synchronous dynamic random access memory (ESDRAM, enhanced Synchronous Dynamic Random Access Memory), synchronous link dynamic random access memory (SLDRAM, syncLink Dynamic Random Access Memory), direct memory bus random access memory (DRRAM, direct Rambus Random Access Memory). The memory cell A2 described in embodiments of the present application is intended to comprise, without being limited to, these and any other suitable types of memory.

Optionally, the controller 1 also comprises a bus connecting the different components (e.g. processor a101 and memory a201, engine management system A3, etc.).

Optionally, the controller 1 in the present embodiment may further include a communication interface (e.g., I/O interface A4) that may be used to communicate with an external device to acquire, for example, vehicle structure information, vehicle travel information, and the like.

Optionally, the controller 1 provided in this embodiment may further include a communication device A5.

The controller 1 provided in the second embodiment of the present application includes a memory a101 and a processor a201, and the processor a101 is configured to execute the computer program A6 stored in the memory a201 to implement the steps of the vehicle control method as described in the first embodiment, so that the controller 1 provided in this embodiment can trigger in advance the adjustment of the engine torque by monitoring the increasing trend of the slip ratio before the traction control system is activated, so as to avoid the situation that the slip ratio of the tire exceeds the optimal slip ratio range due to the response delay after the subsequent traction control system is activated, thereby improving the driving experience of the vehicle.

The second embodiment of the application may also provide a vehicle mounted with the controller 1 as above.

The second embodiment of the present application also provides a computer-readable storage medium storing a computer program A6, which when executed by the processor a101, implements steps of a vehicle control method as described in the first embodiment, such as the steps shown in fig. 1, or such as the steps shown in fig. 2.

Alternatively, the computer-readable storage medium that can be provided by the present embodiment may include any entity or device capable of carrying computer program code, a recording medium, such as ROM, RAM, magnetic disk, optical disk, flash memory, and so forth.

The computer program A6 stored in the computer readable storage medium provided in the second embodiment of the present application can realize that the adjustment of the engine torque is triggered in advance by monitoring the increasing trend of the slip rate before the traction control system is activated when being executed by the processor a101, so as to avoid the situation that the slip rate of the tire exceeds the optimal slip rate range due to the response delay after the subsequent traction control system is activated, thereby improving the driving experience of the vehicle.

Optionally, embodiments of the mobile terminal and the computer readable storage medium provided by the present application include all technical features of each embodiment of the above-mentioned vehicle control method, and the expansion and explanation contents of the description are substantially the same as those of each embodiment of the above-mentioned vehicle control method, which are not repeated herein.

Embodiments of the present application also provide a computer program product comprising computer program code which, when run on a computer, causes the computer to perform the method as in the various possible embodiments described above.

The embodiment of the application also provides a chip, which comprises a memory and a processor, wherein the memory is used for storing a computer program, and the processor is used for calling and running the computer program from the memory, so that the device provided with the chip executes the method in the various possible implementation manners.

The foregoing embodiment numbers of the present application are merely for the purpose of description, and do not represent the advantages or disadvantages of the embodiments.

The steps in the method of the embodiment of the application can be sequentially adjusted, combined and deleted according to actual needs.

The units in the device of the embodiment of the application can be combined, divided and deleted according to actual needs.

In the present application, the same or similar term concept, technical solution and/or application scenario description will be generally described in detail only when first appearing and then repeatedly appearing, and for brevity, the description will not be repeated generally, and in understanding the present application technical solution and the like, reference may be made to the previous related detailed description thereof for the same or similar term concept, technical solution and/or application scenario description and the like which are not described in detail later.

In the present application, the descriptions of the embodiments are emphasized, and the details or descriptions of the other embodiments may be referred to.

The technical features of the technical scheme of the application can be arbitrarily combined, and all possible combinations of the technical features in the above embodiment are not described for the sake of brevity, however, as long as there is no contradiction between the combinations of the technical features, the application shall be considered as the scope of the description of the application.

From the above description of the embodiments, it will be clear to those skilled in the art that the above-described embodiment method may be implemented by means of software plus a necessary general hardware platform, but of course may also be implemented by means of hardware, but in many cases the former is a preferred embodiment. Based on such understanding, the technical solution of the present application may be embodied essentially or in a part contributing to the prior art in the form of a software product stored in a storage medium (e.g. ROM/RAM, magnetic disk, optical disk) as above, comprising instructions for causing a terminal device (which may be a mobile phone, a computer, a server, a controlled terminal, or a network device, etc.) to perform the method of each embodiment of the present application.

In the above embodiments, it may be implemented in whole or in part by software, hardware, firmware, or any combination thereof. When implemented in software, may be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the processes or functions in accordance with embodiments of the present application are produced in whole or in part. The computer may be a general purpose computer, a special purpose computer, a network of computers, or other programmable devices. The computer instructions may be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another computer-readable storage medium, for example, the computer instructions may be transmitted from one website, computer, server, or data center to another website, computer, server, or data center by a wired (e.g., coaxial cable, fiber optic, digital subscriber line), or wireless (e.g., infrared, wireless, microwave, etc.). Computer readable storage media can be any available media that can be accessed by a computer or data storage devices, such as servers, data centers, etc., that contain an integration of one or more available media. Usable media may be magnetic media (e.g., floppy disks, storage disks, magnetic tape), optical media (e.g., DVD), or semiconductor media (e.g., solid state storage disk Solid STATE DISK (SSD)), etc.

The foregoing description is only of the preferred embodiments of the present application, and is not intended to limit the scope of the application, but rather is intended to cover any equivalents of the structures or equivalent processes disclosed herein or in the alternative, which may be employed directly or indirectly in other related arts.

Claims

1. A vehicle control method characterized by comprising:

S1: acquiring a current slip rate and a current required torque;

S2: when the traction control system is not activated, responding to the fact that the current slip rate is larger than or equal to a first slip rate threshold value, and acquiring an engine target torque corresponding to an attachment coefficient of a current road;

s3: a torque adjustment operation is performed based on the engine target torque in response to the current demand torque being greater than the engine target torque.

2. The vehicle control method according to claim 1, characterized in that the S2 step includes:

acquiring the road surface attachment rate under the current slip rate based on vehicle condition information, wherein the vehicle condition information comprises vehicle structure information and vehicle running information;

acquiring the attachment coefficient of the current road based on the road surface attachment rate;

the engine target torque is obtained based on the attachment coefficient.

3. The vehicle control method according to claim 1, characterized in that the step of acquiring the road surface adhesion rate at the current slip rate based on the vehicle condition information includes:

Calculating the road surface attachment rate through a road surface attachment rate calculation formula based on the vehicle condition information:

wherein, the road surface adhesion rate calculation formula:

Phi = Fxb/fz= (m x a)/(G (cos a x b2-sin a x hg)/L- (delta x m x a+ (C _D*A*u²/21.15))xhg/L); or alternatively, the first and second heat exchangers may be,

φ＝Fxb/Fz＝(m*a)/(G*(cosα*b1+sinα*hg)/L+(δ*m*a+(C_D*A*u²/21.15))*hg/L)；

Wherein phi represents the road surface adhesion rate, fxb represents the tangential reaction force of the road surface to the tire, and Fz represents the normal reaction force of the road surface to the tire;

Wherein m represents the mass of the whole vehicle, a represents the longitudinal acceleration of the vehicle, G represents the gravity of the whole vehicle, alpha represents the included angle between the road surface and the horizontal, u represents the vehicle speed, b1 represents the distance from the mass center to the front axle, b2 represents the distance from the mass center to the rear axle, hg represents the distance from the mass center of the whole vehicle to the road surface, C _D represents the wind resistance coefficient, A represents the windward area, L represents the wheelbase, and delta represents the rotational mass conversion coefficient.

4. The vehicle control method according to claim 3, characterized in that the step of obtaining the engine target torque based on the attachment coefficient includes:

Acquiring a vehicle target acceleration based on the attachment coefficient;

Acquiring the target torque of the engine through an engine torque calculation formula based on the acceleration and the power influence factors;

Wherein, the engine torque calculation formula:

T_tq＝(F_f+F_w+F_i+F_j)*r/(i_g*i₀*i_q*η_t)＝(G*f*cosα+C_D*A*u²/21.15+G*sinα+δ*m*a₀)*r/(i_g*i₀*i_q*η_t);

Wherein T _tq represents engine output torque, F _f represents rolling resistance, F _w represents air resistance, F _i represents ramp resistance, F _j represents acceleration resistance, F represents a rolling resistance coefficient, i _g represents a transmission gear ratio, i ₀ represents a final drive gear ratio, i _q represents a clutch engagement ratio, η _t represents mechanical transmission efficiency, r represents wheel rolling radius, a ₀ represents the vehicle target acceleration.

5. The vehicle control method according to claim 1, characterized in that the S3 step includes:

Issuing a torque limiting request based on the engine target torque to control an engine adjustment torque;

and updating the torque limiting request according to a preset period until the traction control system is activated.

6. The vehicle control method according to claim 1, characterized by further comprising:

and activating the traction control system when the current slip rate is greater than or equal to a second slip rate threshold, wherein the second slip rate threshold is greater than the first slip rate threshold.

7. The vehicle control method according to claim 1, characterized by comprising, before the step S3:

Responding to road condition detection, and acquiring a minimum driving torque corresponding to a road condition detection result when the road condition detection result corresponds to a ramp road condition;

Wherein the performing a torque adjustment operation based on the engine target torque includes:

When the target torque of the engine is smaller than the minimum driving torque, performing torque reduction control by using the minimum driving torque; or alternatively, the first and second heat exchangers may be,

And when the engine target torque is not smaller than the minimum driving torque, performing torque reduction control by using the engine target torque.

8. A controller, the controller comprising: a memory, a processor, wherein the memory has stored thereon a computer program which, when executed by the processor, implements the vehicle control method according to any one of claims 1 to 7.

9. A vehicle, characterized in that the vehicle is mounted with a controller according to claim 8.

10. A readable storage medium, characterized in that the readable storage medium has stored thereon a computer program which, when executed by a processor, implements the vehicle control method according to any one of claims 1 to 7.