CN109955719B - Four-wheel drive vehicle and torque distribution method, device and storage medium thereof - Google Patents

Four-wheel drive vehicle and torque distribution method, device and storage medium thereof Download PDF

Info

Publication number
CN109955719B
CN109955719B CN201711405825.1A CN201711405825A CN109955719B CN 109955719 B CN109955719 B CN 109955719B CN 201711405825 A CN201711405825 A CN 201711405825A CN 109955719 B CN109955719 B CN 109955719B
Authority
CN
China
Prior art keywords
axle
wheel
vehicle
slip ratio
torque
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
CN201711405825.1A
Other languages
Chinese (zh)
Other versions
CN109955719A (en
Inventor
郭庆悌
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Borgward Automotive China Co Ltd
Original Assignee
Borgward Automotive China Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Borgward Automotive China Co Ltd filed Critical Borgward Automotive China Co Ltd
Priority to CN201711405825.1A priority Critical patent/CN109955719B/en
Publication of CN109955719A publication Critical patent/CN109955719A/en
Application granted granted Critical
Publication of CN109955719B publication Critical patent/CN109955719B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60K—ARRANGEMENT OR MOUNTING OF PROPULSION UNITS OR OF TRANSMISSIONS IN VEHICLES; ARRANGEMENT OR MOUNTING OF PLURAL DIVERSE PRIME-MOVERS IN VEHICLES; AUXILIARY DRIVES FOR VEHICLES; INSTRUMENTATION OR DASHBOARDS FOR VEHICLES; ARRANGEMENTS IN CONNECTION WITH COOLING, AIR INTAKE, GAS EXHAUST OR FUEL SUPPLY OF PROPULSION UNITS IN VEHICLES
    • B60K17/00—Arrangement or mounting of transmissions in vehicles
    • B60K17/34—Arrangement or mounting of transmissions in vehicles for driving both front and rear wheels, e.g. four wheel drive vehicles
    • B60K17/348—Arrangement or mounting of transmissions in vehicles for driving both front and rear wheels, e.g. four wheel drive vehicles having differential means for driving one set of wheels, e.g. the front, at one speed and the other set, e.g. the rear, at a different speed

Abstract

The disclosure relates to a torque distribution method, a device and a storage medium of a four-wheel drive vehicle, wherein the respective slip rates of a first wheel axle and a second wheel axle of the vehicle are determined according to the current operating parameters of the vehicle; inputting a difference value between the slip ratio of the first axle and the slip ratio of the second axle into a PID controller to obtain a first torque distribution proportion, wherein the first torque distribution proportion is a proportion between torque distributed to the first axle by the vehicle and maximum required torque which can be provided by the vehicle, and the PID controller is used for regulating the first torque distribution proportion so that the difference value between the slip ratio of the first axle and the slip ratio of the second axle is in a preset difference value range; determining the maximum required torque which can be currently provided by the vehicle according to the currently input total required torque; distributing the torque for the first axle and the second axle according to the maximum required torque which can be currently provided by the vehicle and the first torque distribution proportion.

Description

Four-wheel drive vehicle and torque distribution method, device and storage medium thereof
Technical Field
The disclosure relates to the technical field of vehicles, in particular to a four-wheel drive vehicle and a driving torque distribution method, a driving torque distribution device and a storage medium thereof.
Background
The optimization of torque distribution is a key technology for improving the driving capability of the four-wheel drive vehicle, and the good torque distribution can enable the four-wheel drive vehicle to fully utilize the road surface adhesion capability, reduce the vehicle acceleration time and improve the power performance of the vehicle. The existing driving strategy of the four-wheel drive vehicle mainly calculates the torque distribution coefficients of front and rear wheels based on parameters such as pedal opening, vehicle speed, steering angle, maximum road adhesion coefficient and the like, wherein the estimation method of the real-time maximum road adhesion coefficient is complex in process and easy to have deviation, and the calculation result is difficult to apply to the actual vehicle control process. Therefore, under different load conditions, the robustness of torque distribution of the front wheel and the rear wheel is poor, so that the driving performance of the vehicle is difficult to meet the actual requirement.
Disclosure of Invention
The invention mainly aims to provide a four-wheel drive vehicle, a driving torque distribution method and device thereof, and a storage medium, which are used for solving the technical problem that the driving performance of the vehicle is poor due to poor torque distribution of front and rear wheels of the existing four-wheel drive vehicle.
In order to achieve the above object, in a first aspect of the embodiments of the present disclosure, there is provided a torque distribution method of a four-wheel drive vehicle, including:
determining respective slip rates of a first wheel axle and a second wheel axle of a vehicle according to current operating parameters of the vehicle;
inputting a difference value between the slip ratio of the first axle and the slip ratio of the second axle into a PID controller to obtain a first torque distribution proportion, wherein the first torque distribution proportion is a proportion between torque distributed to the first axle by the vehicle and maximum required torque which can be provided by the vehicle, and the PID controller is used for regulating the first torque distribution proportion so that the difference value between the slip ratio of the first axle and the slip ratio of the second axle is in a preset difference value range;
determining the maximum required torque which can be currently provided by the vehicle according to the currently input total required torque;
distributing the torque for the first axle and the second axle according to the maximum required torque which can be currently provided by the vehicle and the first torque distribution proportion.
Optionally, the determining the maximum required torque that the vehicle can currently provide according to the currently input total required torque includes:
determining a second torque distribution ratio according to an optimal slip ratio of the first axle, wherein the second torque distribution ratio is a ratio between the total input required torque and the maximum required torque that can be provided by the vehicle, and the optimal slip ratio is the slip ratio of the front axle when the respective maximum slip ratios of the front and rear wheels are close and the maximum slip ratio of the front wheel is greater than the maximum slip ratio of the rear wheel;
and determining the maximum required torque which can be currently provided by the vehicle according to the currently input total required torque and the second torque distribution proportion.
Optionally, the determining a second torque distribution ratio according to the optimal slip ratio of the first axle comprises:
the second torque distribution ratio k is determined by the following equation1
Figure BDA0001520314310000021
Wherein s is1bestFor an optimum slip ratio, T, of the first wheel axlerequestFor the total required torque of the present input,
Figure BDA0001520314310000022
the maximum required torque that the vehicle can currently provide.
Optionally, the first wheel axle is a front wheel axle of the vehicle, the second wheel axle is a rear wheel axle of the vehicle, and when a difference between a slip ratio of the front wheel axle and a slip ratio of the rear wheel axle is within the preset difference range, the slip ratio of the front wheel axle is greater than the slip ratio of the rear wheel axle.
Optionally, the determining respective slip rates of a first wheel axle and a second wheel axle of the vehicle according to current operating parameters of the vehicle comprises:
acquiring the vehicle speed of the vehicle and the rotation angular speeds of the first wheel shaft and the second wheel shaft;
and determining the respective slip rates of the first wheel shaft and the second wheel shaft according to the vehicle speed and the rotation angular speed.
Optionally, the rotation angular velocity of the first wheel axle is a maximum rotation angular velocity of left and right wheels of the first wheel axle, and the rotation angular velocity of the second wheel axle is a maximum rotation angular velocity of left and right wheels of the second wheel axle.
Optionally, the slip ratio of the first axle is the maximum slip ratio of the left and right wheels of the first axle, and the slip ratio of the second axle is the maximum slip ratio of the left and right wheels of the second axle;
the determining the slip ratio of the first wheel axle according to the vehicle speed and the rotation angular speed comprises: calculating respective slip rates of left and right wheels of the first wheel shaft by the following formula:
Figure BDA0001520314310000031
Figure BDA0001520314310000032
wherein s is1_rSlip ratio, ω, of the right wheel of the first wheel axle1_rAngular velocity of rotation, R, of the right wheel of said first wheel axle1Is the rolling radius of the first axle, s1_lSlip ratio, ω, of the left wheel of the first axle1_lIs the rotational angular velocity of the first wheel axle, u is the vehicle speed of the vehicle;
taking the larger of the slip ratio of the right wheel of the first axle and the slip ratio of the left wheel of the first axle as the slip ratio of the first axle.
Optionally, the distributing the torque to the first axle and the second axle according to the maximum required torque that the vehicle can currently provide and the first torque distribution ratio includes:
torque distributed to the first axle
Figure BDA0001520314310000033
Torque distributed to the second axle
Figure BDA0001520314310000034
Wherein k is the first torque distribution ratio,
Figure BDA0001520314310000035
the maximum required torque that the vehicle can currently provide.
A second aspect of the embodiments of the present disclosure provides a torque distribution device of a four-wheel drive vehicle, including:
the slip rate determining module is used for determining the respective slip rates of a first wheel axle and a second wheel axle of the vehicle according to the current operating parameters of the vehicle;
the PID control module is used for inputting a difference value between the slip ratio of the first axle and the slip ratio of the second axle into a PID controller to obtain a first torque distribution proportion, wherein the first torque distribution proportion is a proportion between torque distributed to the first axle by the vehicle and maximum required torque which can be provided by the vehicle, and the PID controller is used for regulating the first torque distribution proportion to enable the difference value between the slip ratio of the first axle and the slip ratio of the second axle to be within a preset difference value range;
the torque determination module is used for determining the maximum required torque which can be provided by the vehicle at present according to the total required torque input at present;
and the torque distribution module is used for distributing the torque to the first wheel axle and the second wheel axle according to the maximum required torque which can be currently provided by the vehicle and the first torque distribution proportion.
Optionally, the torque determination module is to:
a proportion determination submodule for determining a second torque distribution proportion according to an optimum slip ratio of the first axle, wherein the second torque distribution proportion is a proportion between an input total required torque and a maximum required torque that can be provided by the vehicle, and the optimum slip ratio is a slip ratio of the front axle when respective maximum slip ratios of front and rear wheels are close and a front wheel maximum slip ratio is greater than a rear wheel maximum slip ratio;
and the torque determination submodule is used for determining the maximum required torque which can be currently provided by the vehicle according to the total required torque which is currently input and the second torque distribution proportion.
Optionally, the ratio determination submodule is configured to:
the second torque distribution ratio k is determined by the following equation1
Figure BDA0001520314310000041
Wherein s is1bestFor an optimum slip ratio, T, of the first wheel axlerequestFor the current inputThe total required torque is set to be,
Figure BDA0001520314310000051
the maximum required torque that the vehicle can currently provide.
Optionally, the first wheel axle is a front wheel axle of the vehicle, the second wheel axle is a rear wheel axle of the vehicle, and when a difference between a slip ratio of the front wheel axle and a slip ratio of the rear wheel axle is within the preset difference range, the slip ratio of the front wheel axle is greater than the slip ratio of the rear wheel axle.
Optionally, the slip ratio determination module comprises:
an obtaining submodule for obtaining a vehicle speed of the vehicle and rotational angular velocities of the first wheel axle and the second wheel axle;
and the slip rate determining submodule is used for determining the slip rates of the first wheel shaft and the second wheel shaft according to the vehicle speed and the rotation angular speed.
Optionally, the rotation angular velocity of the first wheel axle is a maximum rotation angular velocity of left and right wheels of the first wheel axle, and the rotation angular velocity of the second wheel axle is a maximum rotation angular velocity of left and right wheels of the second wheel axle.
Optionally, the slip ratio of the first axle is the maximum slip ratio of the left and right wheels of the first axle, and the slip ratio of the second axle is the maximum slip ratio of the left and right wheels of the second axle;
the slip rate determination submodule is configured to:
calculating respective slip rates of left and right wheels of the first wheel shaft by the following formula:
Figure BDA0001520314310000052
Figure BDA0001520314310000053
wherein s is1_rSlip of the right wheel of the first wheel axleRate, ω1_rAngular velocity of rotation, R, of the right wheel of said first wheel axle1Is the rolling radius of the first axle, s1_lSlip ratio, ω, of the left wheel of the first axle1_lIs the rotational angular velocity of the first wheel axle, u is the vehicle speed of the vehicle;
taking the larger of the slip ratio of the right wheel of the first axle and the slip ratio of the left wheel of the first axle as the slip ratio of the first axle.
A third aspect of the embodiments of the present disclosure provides a computer-readable storage medium, on which a computer program is stored, which when executed by a processor implements the steps of the method of the first aspect.
A fourth aspect of the embodiments of the present disclosure provides a torque distribution device for a four-wheel drive vehicle, including:
the computer-readable storage medium of the third aspect; and
one or more processors to execute the program in the computer-readable storage medium.
A fifth aspect of the embodiments of the present disclosure provides a four-wheel drive vehicle including the torque distribution device of the four-wheel drive vehicle of the second or fourth aspect.
It should be noted that, on the same road surface, the front and rear wheel adhesion coefficients of the vehicle are the same, the corresponding slip ratios are also the same, and the vehicle has the maximum driving capability when the front and rear wheel slip ratios of the vehicle are the same and approach the optimal slip ratio. According to the technical scheme, the difference value of the slip ratios of the front axle and the rear axle of the vehicle is input into the PID controller to output a proper first torque distribution ratio, and torques are distributed to the front wheel and the rear wheel of the vehicle according to the maximum required torque which can be provided by the vehicle and the first torque distribution ratio, so that the slip ratios of the front axle and the rear axle approach to the same optimal slip ratio.
Additional features and advantages of the disclosure will be set forth in the detailed description which follows.
Drawings
The accompanying drawings, which are included to provide a further understanding of the disclosure and are incorporated in and constitute a part of this specification, illustrate embodiments of the disclosure and together with the description serve to explain the disclosure without limiting the disclosure. In the drawings:
FIG. 1 is a flow chart illustrating a method of torque distribution for a four-wheel drive vehicle according to an exemplary embodiment.
FIG. 2 is a flow chart illustrating a method of torque distribution for a four-wheel drive vehicle according to an exemplary embodiment.
FIG. 3 is a block diagram illustrating a torque distribution arrangement for a four-wheel drive vehicle according to an exemplary embodiment.
FIG. 4 is a block diagram illustrating a torque distribution arrangement for a four-wheel drive vehicle according to an exemplary embodiment.
FIG. 5 is a block diagram illustrating a torque distribution arrangement for a four-wheel drive vehicle according to an exemplary embodiment.
Detailed Description
The following detailed description of specific embodiments of the present disclosure is provided in connection with the accompanying drawings. It should be understood that the detailed description and specific examples, while indicating the present disclosure, are given by way of illustration and explanation only, not limitation.
FIG. 1 is a flow chart illustrating a method of torque distribution for a four-wheel drive vehicle, as shown in FIG. 1, including the steps of:
step 101, determining respective slip rates of a first wheel axle and a second wheel axle of a vehicle according to current operating parameters of the vehicle.
The operating parameters may include the current vehicle speed of the vehicle and the respective rotational angular speeds of the front and rear wheel axles.
It should be noted that the first axle may be a front axle (the second axle is a rear axle), or may be a rear axle (the first axle is a front axle), which is not limited in the embodiment of the present disclosure.
And 102, inputting the difference value between the slip ratio of the first wheel axle of the vehicle and the slip ratio of the second wheel axle of the vehicle into a PID controller to obtain a first torque distribution proportion.
The PID controller is used for regulating the first torque distribution proportion so that the difference value between the slip ratio of the first wheel axle and the slip ratio of the second wheel axle is in a preset difference value range.
The PID (proportional-integral-derivative) controller consists of a proportional unit, an integral unit and a differential unit, and performs deviation regulation on a system with the basic linear and dynamic characteristics unchanged along with time based on a PID control principle to ensure that the actual value of a controlled variable is consistent with a preset value required by industry. The parameter of the PID controller has a proportionality coefficient KpIntegral coefficient KiAnd a differential coefficient Kd. The parameters of the PID controller can be adjusted through theoretical calculation or an engineering adjustment method, and in practical application, the parameters of the PID can be adjusted and perfected according to the difference value between the slip rate of the first wheel axle and the slip rate of the second wheel axle. The PID controller is used for regulating and controlling the proportion between the torque distributed to the first wheel axle and the maximum required torque which can be provided by the vehicle, so that the difference value between the slip rate of the first wheel axle and the slip rate of the second wheel axle is within a preset difference value range. It should be noted that, since the vehicle may have the maximum driving capability when the slip rates of the front and rear wheel shafts are equal, the difference range may be preset to be appropriate in the specific implementation, so that the front wheel reaches the optimum slip rate first to prevent the vehicle from being unstable.
Step 103, determining the maximum required torque which can be provided by the vehicle at present according to the total required torque input at present.
The input total demand torque refers to a driving torque which is correspondingly output by a vehicle driving system according to parameters such as an accelerator opening degree, a vehicle speed and a steering angle when a driver drives the vehicle, and the maximum demand torque which can be provided by the vehicle refers to the maximum demand torque which can be provided by the vehicle at present and is obtained by converting the total demand torque input by the driver based on the load, the current running state and the like of the vehicle. For example, in order to avoid excessive slip of the front and rear wheels before the optimal slip rate is reached, when the total required torque input by the driver is excessive, it may be converted into a smaller torque to be redistributed to the front and rear wheels of the vehicle.
For example, the total required torque of the inputs is defined as
Figure BDA0001520314310000081
The maximum required torque that the vehicle can provide is TrequestThe total required torque satisfies the relationship with the maximum required torque that can be provided
Figure BDA0001520314310000082
Figure BDA0001520314310000083
k1The value range of (2) is 0-1, and the specific value can be set according to the actual requirement.
Step 104, distributing the torque for the first axle and the second axle according to the maximum required torque which can be currently provided by the vehicle and the first torque distribution ratio.
Specifically, if the first torque distribution ratio is k, the torque distributed to the first axle of the vehicle is
Figure BDA0001520314310000084
Torque distributed to the second axle
Figure BDA0001520314310000085
The maximum required torque that can be currently provided by the vehicle.
By adopting the method, the difference value of the slip ratios of the front and rear axles of the vehicle is input into the PID controller to output a proper first torque distribution proportion, and torques are distributed to the front and rear wheels of the vehicle according to the maximum required torque which can be provided by the vehicle and the first torque distribution proportion, so that the slip ratios of the front and rear axles approach to the same optimal slip ratio.
In order to make those skilled in the art understand the technical solutions provided by the embodiments of the present disclosure, the following detailed descriptions of the above method steps are provided.
Optionally, step 101 may comprise: the method comprises the steps of obtaining the vehicle speed of a vehicle and the rotating angular speeds of a first wheel shaft and a second wheel shaft, and determining the respective slip rates of the first wheel shaft and the second wheel shaft according to the vehicle speed and the rotating angular speeds.
In specific implementation, considering that the models, the wear degrees, the driving road conditions, and the like of the left and right tires on the same axle may be different, the rotation angular velocity of the first axle obtained in the embodiment of the present disclosure may be the maximum rotation angular velocity of the left and right wheels of the first axle, and the rotation angular velocity of the second axle obtained may be the maximum rotation angular velocity of the left and right wheels of the second axle.
For example, the respective slip rates of the front and rear wheel shafts can be calculated by the following formula:
Figure BDA0001520314310000091
Figure BDA0001520314310000092
wherein s is1Is the slip ratio of the first wheel axle, omega1Is the maximum rotational angular velocity, R, of the left and right wheels of the first wheel axle1Is the rolling radius of the first axle, s2Slip ratio of the second wheel axle, ω2Is the maximum rotational angular velocity, R, of the left and right wheels of the second wheel axle2Is the rolling radius of the second axle and u is the vehicle speed.
In another possible implementation, the slip rates of the left and right wheels may be calculated respectively, and the maximum slip rates of the left and right wheels may be used as the slip rates of the wheel shafts. That is, the respective slip rates of the first and second axles may be the maximum slip rates of the first axle left and right wheels and the second axle left and right wheels.
Taking the example of calculating the slip ratio of the first axle, the embodiments of the present disclosure may calculate the slip ratio of the left wheel and the right wheel of the first axle by the following formula:
Figure BDA0001520314310000101
Figure BDA0001520314310000102
wherein s is1_rSlip ratio, ω, of the right wheel of the first wheel axle1_rAngular velocity of rotation, R, of the right wheel of said first wheel axle1Is the rolling radius of the first axle, s1_lSlip ratio, ω, of the left wheel of the first axle1_lThe rotational angular velocity of the left wheel of the first wheel axle is the vehicle speed of the vehicle. Taking the larger of the slip ratio of the right wheel of the first axle and the slip ratio of the left wheel of the first axle as the slip ratio of the first axle. Similarly, the slip rates of the left wheel and the right wheel of the second wheel shaft can be calculated by adopting the method, and the larger slip rate is selected as the slip rate of the second wheel shaft.
Optionally, the first wheel axle is a front wheel axle of the vehicle, the second wheel axle is a rear wheel axle of the vehicle, and when a difference between a slip ratio of the front wheel axle and a slip ratio of the rear wheel axle is within the preset difference range, the slip ratio of the front wheel axle is greater than the slip ratio of the rear wheel axle. That is to say, the preset difference range is a difference range obtained by subtracting the slip rate of the rear axle from the slip rate of the front axle of the vehicle, and the preset difference range is a positive range, so that when the difference value of the slip rates of the front and rear axles of the vehicle is within the preset difference range, the slip rate of the front axle of the vehicle is greater than the slip rate of the rear axle, and the tail flick phenomenon of the vehicle caused by the fact that the slip rate of the rear axle is greater than that of the front axle is avoided.
FIG. 2 is a flow chart illustrating a method of torque distribution for a four-wheel drive vehicle, as shown in FIG. 2, including the steps of:
step 201, obtaining a vehicle speed of a vehicle and rotation angular speeds of a first wheel axle and a second wheel axle.
And step 202, determining respective slip rates of the first wheel axle and the second wheel axle according to the vehicle speed and the rotation angular speed.
Step 203, inputting the difference value between the slip ratio of the first wheel axle and the slip ratio of the second wheel axle into a PID controller to obtain a first torque distribution ratio.
And step 204, determining a second torque distribution proportion according to the optimal slip ratio of the first wheel axle.
Wherein the second torque distribution ratio is a ratio between the total required torque input and the maximum required torque that the vehicle can provide. The optimum slip ratio is a slip ratio of the front wheel shaft when the maximum slip ratios of the front and rear wheels are close to each other and the maximum slip ratio of the front wheel is larger than the maximum slip ratio of the rear wheel.
For example, step 204 may determine the second torque distribution ratio k by the following formula1
Figure BDA0001520314310000111
Wherein s is1bestFor an optimum slip ratio, T, of the first wheel axlerequestFor the total required torque of the present input,
Figure BDA0001520314310000112
the maximum required torque that the vehicle can currently provide.
The above is merely an example, and in the specific implementation, the second torque distribution ratio may be set according to an actual requirement, which is not limited by the present disclosure.
In step 205, the maximum required torque which can be currently provided by the vehicle is determined according to the currently input total required torque and the second torque distribution ratio.
In step 206, torque is distributed to the first axle and the second axle according to the maximum required torque that can be currently provided by the vehicle and the first torque distribution ratio.
It is noted that for simplicity of description, the above method embodiments are described as a series of acts or combination of acts, but those skilled in the art will recognize that the present disclosure is not limited by the order of acts or combination of acts described. For example, step 203 and step 204 shown in fig. 2 are both executed after step 202, but in specific implementation, the execution order of the two steps may be set according to actual needs, and step 203 may be executed first and then step 204 is executed, or step 204 may be executed first and then step 203 is executed.
By adopting the method, the proportion (the second driving torque distribution proportion) between the total required torque input by the operation of the driver and the maximum required torque which can be provided by the vehicle is set, so that the situation that any excessive slip occurs before the front wheel and the rear wheel simultaneously reach the optimal slip rate due to overlarge torque is avoided, the rear axle wheels are prevented from slipping first, and the running stability of the vehicle is improved.
Fig. 2 provides a possible way to calculate the second torque distribution ratio, and it should be understood by those skilled in the art that other ways to calculate the second torque distribution ratio may be also conceivable within the scope of the present disclosure, for example, inputting the difference between the slip ratio of the first axle and the optimal slip ratio of the first axle into a PID controller to obtain the second torque distribution ratio, and by designing a PID controller reasonably, it can be ensured that the rear wheels will not slip before the front wheels and the rear wheels simultaneously tend to the optimal slip ratio under the second torque distribution ratio. Such simple variations are within the scope of the present disclosure.
Fig. 3 is a block diagram illustrating a torque distribution apparatus 300 for a four-wheel-drive vehicle, according to an exemplary embodiment, where the apparatus 300 may be implemented as part or all of a four-wheel-drive vehicle drive system through software, hardware, or a combination of both. As shown in fig. 3, the apparatus 300 includes:
a slip rate determination module 310, configured to determine respective slip rates of a first wheel axle and a second wheel axle of a vehicle according to current operating parameters of the vehicle;
the PID control module 320 is configured to input a difference between the slip ratio of the first axle and the slip ratio of the second axle to a PID controller, so as to obtain a first torque distribution ratio, where the first torque distribution ratio is a ratio between a torque distributed to the first axle by the vehicle and a maximum required torque that can be provided by the vehicle, and the PID controller is configured to regulate and control the first torque distribution ratio, so that the difference between the slip ratio of the first axle and the slip ratio of the second axle is within a preset difference range;
a torque determination module 330, configured to determine a maximum required torque that can be currently provided by the vehicle according to a currently input total required torque;
a torque distribution module 340, configured to distribute the torque to the first axle and the second axle according to the maximum required torque that can be currently provided by the vehicle and the first torque distribution ratio.
By adopting the device, the difference value of the slip ratios of the front and rear wheel shafts of the vehicle is input into the PID controller to output a proper first torque distribution proportion, and torques are distributed to the front and rear wheels of the vehicle according to the maximum required torque which can be provided by the vehicle and the first torque distribution proportion, so that the slip ratios of the front and rear wheel shafts approach to the same optimal slip ratio.
FIG. 4 is a block diagram illustrating another torque distribution apparatus 300 for a four-wheel-drive vehicle, according to an exemplary embodiment, where the apparatus 300 may be implemented as part or all of a four-wheel-drive vehicle drive system through software, hardware, or a combination of both. As shown in FIG. 4, the torque determination module 330 is configured to:
a proportion determination submodule 331 configured to determine a second torque distribution proportion according to an optimal slip ratio of the first axle, where the second torque distribution proportion is a proportion between an input total required torque and a maximum required torque that can be provided by the vehicle, and the optimal slip ratio is a slip ratio of the front axle when respective maximum slip ratios of front and rear wheels are close and a front wheel maximum slip ratio is greater than a rear wheel maximum slip ratio;
and a torque determination submodule 332, configured to determine a maximum required torque that can be currently provided by the vehicle according to the currently input total required torque and the second torque distribution ratio.
Optionally, the ratio determining sub-module 331 is configured to:
the second torque distribution ratio k is determined by the following equation1
Figure BDA0001520314310000131
Wherein s is1bestFor an optimum slip ratio, T, of the first wheel axlerequestFor the total required torque of the present input,
Figure BDA0001520314310000132
the maximum required torque that the vehicle can currently provide.
Optionally, the first wheel axle is a front wheel axle of the vehicle, the second wheel axle is a rear wheel axle of the vehicle, and when a difference between a slip ratio of the front wheel axle and a slip ratio of the rear wheel axle is within the preset difference range, the slip ratio of the front wheel axle is greater than the slip ratio of the rear wheel axle.
Optionally, the slip ratio determination module 310 comprises:
an obtaining submodule 311 configured to obtain a vehicle speed of the vehicle and rotational angular velocities of the first wheel axle and the second wheel axle;
a slip ratio determination submodule 312 configured to determine respective slip ratios of the first wheel axle and the second wheel axle according to the vehicle speed and the rotational angular speed.
Optionally, the rotation angular velocity of the first wheel axle is a maximum rotation angular velocity of left and right wheels of the first wheel axle, and the rotation angular velocity of the second wheel axle is a maximum rotation angular velocity of left and right wheels of the second wheel axle.
Optionally, the slip ratio of the first axle is the maximum slip ratio of the left and right wheels of the first axle, and the slip ratio of the second axle is the maximum slip ratio of the left and right wheels of the second axle;
the slip rate determination sub-module 312 is configured to:
calculating respective slip rates of left and right wheels of the first wheel shaft by the following formula:
Figure BDA0001520314310000141
Figure BDA0001520314310000142
wherein s is1_rSlip ratio, ω, of the right wheel of the first wheel axle1_rAngular velocity of rotation, R, of the right wheel of said first wheel axle1Is the rolling radius of the first axle, s1_lSlip ratio, ω, of the left wheel of the first axle1_lIs the rotational angular velocity of the first wheel axle, u is the vehicle speed of the vehicle;
taking the larger of the slip ratio of the right wheel of the first axle and the slip ratio of the left wheel of the first axle as the slip ratio of the first axle.
With regard to the apparatus in the above-described embodiment, the specific manner in which each module performs the operation has been described in detail in the embodiment related to the method, and will not be elaborated here.
FIG. 5 is a block diagram illustrating a torque distribution arrangement 500 for a four-wheel drive vehicle, according to an exemplary embodiment. As shown in fig. 5, the torque distribution device 500 of the four-wheel drive vehicle may include: a processor 501, a memory 502, a multimedia component 503, an input/output (I/O) interface 504, and a communication component 505.
The processor 501 is used for controlling the overall operation of the torque distribution device 500 of the four-wheel drive vehicle, so as to complete all or part of the steps in the torque distribution method of the four-wheel drive vehicle. The memory 502 is used to store various types of data to support the operation of the torque distribution device 500 of the four-wheel drive vehicle, which may include, for example, instructions for any application or method operating on the torque distribution device 500 of the four-wheel drive vehicle, as well as application-related data.
The Memory 502 may be implemented by any type of volatile or non-volatile Memory device or combination thereof, such as Static Random Access Memory (SRAM), Electrically Erasable Programmable Read-Only Memory (EEPROM), Erasable Programmable Read-Only Memory (EPROM), Programmable Read-Only Memory (PROM), Read-Only Memory (ROM), magnetic Memory, flash Memory, magnetic disk or optical disk.
The multimedia component 503 may include a screen, which may be, for example, a touch screen, and an audio component for outputting and/or inputting audio signals. The received audio signal may further be stored in the memory 502 or transmitted through the communication component 505. The audio assembly also includes at least one speaker for outputting audio signals.
The I/O interface 504 provides an interface between the processor 501 and other interface modules, which may be a keyboard, buttons, etc. These buttons may be virtual buttons or physical buttons.
The communication component 505 is used for wired or wireless communication between the torque distribution device 500 of the four-wheel drive vehicle and other equipment. Wireless Communication, such as Wi-Fi, bluetooth, Near Field Communication (NFC), 2G, 3G, or 4G, or a combination of one or more of them, so that the corresponding Communication component 505 may include: Wi-Fi module, bluetooth module, NFC module.
In an exemplary embodiment, the torque distribution apparatus 500 of the four-wheel drive vehicle may be implemented by one or more Application Specific Integrated Circuits (ASICs), Digital Signal Processors (DSPs), Digital Signal Processing Devices (DSPDs), Programmable Logic Devices (PLDs), Field Programmable Gate Arrays (FPGAs), controllers, microcontrollers, microprocessors or other electronic components for performing the torque distribution method of the four-wheel drive vehicle.
The disclosed embodiments provide a computer readable storage medium comprising program instructions, such as a memory 502 comprising program instructions, having one or more computer programs stored thereon that are executable by a processor 501 of a torque distribution apparatus 500 of a four-wheel drive vehicle to perform the torque distribution method of the four-wheel drive vehicle provided by the disclosed embodiments.
The embodiment of the present disclosure further provides an electric four-wheel-drive vehicle, which includes the torque distribution device of the four-wheel-drive vehicle provided in the embodiment of the present disclosure, and specific reference is made to the above corresponding description, which is not repeated herein.
The preferred embodiments of the present disclosure are described in detail with reference to the accompanying drawings, however, the present disclosure is not limited to the specific details of the above embodiments, and various simple modifications may be made to the technical solution of the present disclosure within the technical idea of the present disclosure, and these simple modifications all belong to the protection scope of the present disclosure.
It should be noted that the various features described in the above embodiments may be combined in any suitable manner without departing from the scope of the invention. In order to avoid unnecessary repetition, various possible combinations will not be separately described in this disclosure.
In addition, any combination of various embodiments of the present disclosure may be made, and the same should be considered as the disclosure of the present disclosure, as long as it does not depart from the spirit of the present disclosure.

Claims (17)

1. A method of torque distribution for a four-wheel drive vehicle, comprising:
determining the slip rates of a first wheel axle and a second wheel axle of the vehicle respectively according to the current operating parameters of the vehicle;
inputting a difference value between the slip ratio of the first axle and the slip ratio of the second axle into a PID controller to obtain a first torque distribution proportion, wherein the first torque distribution proportion is a proportion between torque distributed to the first axle by the vehicle and maximum required torque which can be provided by the vehicle, and the PID controller is used for regulating the first torque distribution proportion so that the difference value between the slip ratio of the first axle and the slip ratio of the second axle is in a preset difference value range;
determining the maximum required torque which can be currently provided by the vehicle according to the currently input total required torque;
distributing the torque for the first axle and the second axle according to the maximum required torque which can be currently provided by the vehicle and the first torque distribution proportion.
2. The method of claim 1, wherein said determining a maximum requested torque that the vehicle can currently provide based on the currently input total requested torque comprises:
determining a second torque distribution proportion according to the optimal slip ratio of the first wheel shaft, wherein the second torque distribution proportion is the proportion between the input total required torque and the maximum required torque which can be provided by the vehicle, and the optimal slip ratio is the slip ratio of the front wheel shaft when the maximum slip ratios of the front wheel and the rear wheel are close and the maximum slip ratio of the front wheel is greater than the maximum slip ratio of the rear wheel;
and determining the maximum required torque which can be currently provided by the vehicle according to the currently input total required torque and the second torque distribution proportion.
3. The method of claim 2, wherein determining a second torque distribution ratio based on the optimal slip ratio for the first axle comprises:
the second torque distribution ratio k is determined by the following equation1
Figure FDA0002599496930000021
Wherein s is1bestFor an optimum slip ratio, T, of the first wheel axlerequestFor the total required torque of the present input,
Figure FDA0002599496930000022
the maximum required torque that the vehicle can currently provide.
4. The method according to claim 1, wherein the first wheel axle is a front wheel axle of the vehicle, the second wheel axle is a rear wheel axle of the vehicle, and the slip ratio of the front wheel axle is greater than the slip ratio of the rear wheel axle when the difference between the slip ratio of the front wheel axle and the slip ratio of the rear wheel axle is within the preset difference range.
5. A method according to any one of claims 1-4, wherein said determining the slip ratio of the first and second wheel axle of the vehicle, respectively, depending on the current operating parameters of the vehicle, comprises:
acquiring the vehicle speed of the vehicle and the rotation angular speeds of the first wheel shaft and the second wheel shaft;
and respectively determining the slip rates of the first wheel shaft and the second wheel shaft according to the vehicle speed and the rotation angular speed.
6. The method of claim 5, wherein the rotational angular velocity of the first axle is a maximum rotational angular velocity of the left and right wheels of the first axle and the rotational angular velocity of the second axle is a maximum rotational angular velocity of the left and right wheels of the second axle.
7. The method of claim 5, wherein the slip ratio of the first axle is a maximum slip ratio of the left and right wheels of the first axle, and the slip ratio of the second axle is a maximum slip ratio of the left and right wheels of the second axle;
the determining the slip ratio of the first wheel axle according to the vehicle speed and the rotation angular speed comprises: calculating slip rates of left and right wheels of the first wheel shaft respectively by the following formula:
Figure FDA0002599496930000031
Figure FDA0002599496930000032
wherein s is1_rSlip ratio, ω, of the right wheel of the first wheel axle1_rAngular velocity of rotation, R, of the right wheel of said first wheel axle1Is the rolling radius of the first axle, s1_lSlip ratio, ω, of the left wheel of the first axle1_lIs the rotational angular velocity of the first wheel axle, u is the vehicle speed of the vehicle;
taking the larger of the slip ratio of the right wheel of the first axle and the slip ratio of the left wheel of the first axle as the slip ratio of the first axle.
8. A torque distribution device for a four-wheel-drive vehicle, comprising:
the slip rate determining module is used for respectively determining the slip rates of a first wheel axle and a second wheel axle of the vehicle according to the current running parameters of the vehicle;
the PID control module is used for inputting a difference value between the slip ratio of the first axle and the slip ratio of the second axle into a PID controller to obtain a first torque distribution proportion, wherein the first torque distribution proportion is a proportion between torque distributed to the first axle by the vehicle and maximum required torque which can be provided by the vehicle, and the PID controller is used for regulating the first torque distribution proportion to enable the difference value between the slip ratio of the first axle and the slip ratio of the second axle to be within a preset difference value range;
the torque determination module is used for determining the maximum required torque which can be provided by the vehicle at present according to the total required torque input at present;
and the torque distribution module is used for distributing the torque to the first wheel axle and the second wheel axle according to the maximum required torque which can be currently provided by the vehicle and the first torque distribution proportion.
9. The apparatus of claim 8, wherein the torque determination module is to:
a proportion determination submodule for determining a second torque distribution proportion according to an optimal slip ratio of the first axle, wherein the second torque distribution proportion is a proportion between the input total required torque and the maximum required torque that can be provided by the vehicle, and the optimal slip ratio is the slip ratio of the front axle when the maximum slip ratios of the front and rear wheels are close and the maximum slip ratio of the front wheel is greater than the maximum slip ratio of the rear wheel;
and the torque determination submodule is used for determining the maximum required torque which can be currently provided by the vehicle according to the total required torque which is currently input and the second torque distribution proportion.
10. The apparatus of claim 9, wherein the ratio determination submodule is configured to:
the second torque distribution ratio k is determined by the following equation1
Figure FDA0002599496930000041
Wherein s is1bestFor an optimum slip ratio, T, of the first wheel axlerequestFor the total required torque of the present input,
Figure FDA0002599496930000042
the maximum required torque that the vehicle can currently provide.
11. The apparatus of claim 8, wherein the first wheel axle is a front wheel axle of the vehicle, the second wheel axle is a rear wheel axle of the vehicle, and when a difference between a slip ratio of the front wheel axle and a slip ratio of the rear wheel axle is within the preset difference range, the slip ratio of the front wheel axle is greater than the slip ratio of the rear wheel axle.
12. The apparatus of any of claims 8 to 11, wherein the slip ratio determination module comprises:
an obtaining submodule for obtaining a vehicle speed of the vehicle and rotational angular velocities of the first wheel axle and the second wheel axle;
and the slip rate determining submodule is used for respectively determining the slip rates of the first wheel shaft and the second wheel shaft according to the vehicle speed and the rotation angular speed.
13. The apparatus of claim 12, wherein the rotational angular velocity of the first axle is a maximum rotational angular velocity of the left and right wheels of the first axle, and the rotational angular velocity of the second axle is a maximum rotational angular velocity of the left and right wheels of the second axle.
14. The apparatus of claim 12, wherein the slip ratio of the first axle is a maximum slip ratio of the left and right wheels of the first axle, and the slip ratio of the second axle is a maximum slip ratio of the left and right wheels of the second axle;
the slip rate determination submodule is configured to:
calculating slip rates of left and right wheels of the first wheel shaft respectively by the following formula:
Figure FDA0002599496930000051
Figure FDA0002599496930000052
wherein s is1_rSlip ratio, ω, of the right wheel of the first wheel axle1_rAngular velocity of rotation, R, of the right wheel of said first wheel axle1Is the rolling radius of the first axle, s1_lSlip ratio, ω, of the left wheel of the first axle1_lIs the rotational angular velocity of the first wheel axle, u is the vehicle speed of the vehicle;
taking the larger of the slip ratio of the right wheel of the first axle and the slip ratio of the left wheel of the first axle as the slip ratio of the first axle.
15. A computer-readable storage medium, on which a computer program is stored which, when being executed by a processor, carries out the steps of the method according to any one of claims 1 to 7.
16. A torque distribution device for a four-wheel-drive vehicle, comprising:
the computer-readable storage medium recited in claim 15; and
one or more processors to execute the program in the computer-readable storage medium.
17. A four-wheel-drive vehicle, characterized by comprising the torque distribution device of the four-wheel-drive vehicle of any one of claims 8 to 14 or 16.
CN201711405825.1A 2017-12-22 2017-12-22 Four-wheel drive vehicle and torque distribution method, device and storage medium thereof Active CN109955719B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201711405825.1A CN109955719B (en) 2017-12-22 2017-12-22 Four-wheel drive vehicle and torque distribution method, device and storage medium thereof

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201711405825.1A CN109955719B (en) 2017-12-22 2017-12-22 Four-wheel drive vehicle and torque distribution method, device and storage medium thereof

Publications (2)

Publication Number Publication Date
CN109955719A CN109955719A (en) 2019-07-02
CN109955719B true CN109955719B (en) 2020-12-15

Family

ID=67019380

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201711405825.1A Active CN109955719B (en) 2017-12-22 2017-12-22 Four-wheel drive vehicle and torque distribution method, device and storage medium thereof

Country Status (1)

Country Link
CN (1) CN109955719B (en)

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2007131192A (en) * 2005-11-11 2007-05-31 Suzuki Motor Corp Device for controlling distribution of driving power of vehicle
CN101223047A (en) * 2005-07-19 2008-07-16 三菱自动车工业株式会社 Differential limiting control device of four-wheel drive vehicle
CN102826087A (en) * 2012-08-31 2012-12-19 长城汽车股份有限公司 Torque control method of automobile four-drive system
CN104477164A (en) * 2014-11-20 2015-04-01 北京新能源汽车股份有限公司 Acceleration anti-slip control system and method of pure electric vehicle
CN104828067A (en) * 2014-12-19 2015-08-12 北汽福田汽车股份有限公司 Four-wheel drive hybrid electric vehicle travelling power generation control method and power system thereof
CN105460001A (en) * 2014-07-25 2016-04-06 比亚迪股份有限公司 Torque distribution method and device for four-wheel drive system of electric automobile
CN105946852A (en) * 2016-06-07 2016-09-21 东风汽车公司 Antiskid system of car and control method of antiskid system
CN106043284A (en) * 2015-04-07 2016-10-26 现代自动车株式会社 Control method for front and rear wheel torque distribution of electric 4 wheel drive hybrid electric vehicle
CN106515509A (en) * 2017-01-03 2017-03-22 重庆长安汽车股份有限公司 Driving system for electric four-wheel-drive vehicle and torque distribution method of driving system

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101223047A (en) * 2005-07-19 2008-07-16 三菱自动车工业株式会社 Differential limiting control device of four-wheel drive vehicle
JP2007131192A (en) * 2005-11-11 2007-05-31 Suzuki Motor Corp Device for controlling distribution of driving power of vehicle
CN102826087A (en) * 2012-08-31 2012-12-19 长城汽车股份有限公司 Torque control method of automobile four-drive system
CN105460001A (en) * 2014-07-25 2016-04-06 比亚迪股份有限公司 Torque distribution method and device for four-wheel drive system of electric automobile
CN104477164A (en) * 2014-11-20 2015-04-01 北京新能源汽车股份有限公司 Acceleration anti-slip control system and method of pure electric vehicle
CN104828067A (en) * 2014-12-19 2015-08-12 北汽福田汽车股份有限公司 Four-wheel drive hybrid electric vehicle travelling power generation control method and power system thereof
CN106043284A (en) * 2015-04-07 2016-10-26 现代自动车株式会社 Control method for front and rear wheel torque distribution of electric 4 wheel drive hybrid electric vehicle
CN105946852A (en) * 2016-06-07 2016-09-21 东风汽车公司 Antiskid system of car and control method of antiskid system
CN106515509A (en) * 2017-01-03 2017-03-22 重庆长安汽车股份有限公司 Driving system for electric four-wheel-drive vehicle and torque distribution method of driving system

Also Published As

Publication number Publication date
CN109955719A (en) 2019-07-02

Similar Documents

Publication Publication Date Title
JP6162762B2 (en) Vehicle control apparatus and vehicle control method
US10442310B1 (en) Vehicle yaw and energy efficiency control apparatus to dynamically assign torque among independently powered drive wheels
US8544592B2 (en) Steering apparatus for vehicle
JP5250541B2 (en) Differential limiting control device for electric vehicle
CN107709085B (en) Vehicle attitude control device
JP6616158B2 (en) Slip control device
CN107848526B (en) Vehicle turning control device
WO2016121546A1 (en) Vehicle orientation control device
JP5835583B2 (en) Driving force control device for electric vehicle
JP2016022885A (en) Driving torque distribution control device for four-wheel drive car
US10414401B2 (en) Controller and method
JP2016215745A (en) Vehicular control apparatus
KR102277285B1 (en) Apparatus for controlling rear wheel steering and method thereof
JPH07323859A (en) Controller for movement of vehicle
CN110654244A (en) System and method for decentralized driving of hub motor
KR20130052790A (en) Vehicle dynamic performance improvement apparatus and method for the same
JP6020510B2 (en) Vehicle control device
WO2023131274A1 (en) Front-drive vehicle torque control method and apparatus, and vehicle
JP2011236810A (en) Driving force control device of vehicle
JP2013192446A (en) Differential limit control device for electric vehicle
JP5848150B2 (en) Control device for controlling driving force acting on vehicle
CN109955719B (en) Four-wheel drive vehicle and torque distribution method, device and storage medium thereof
WO2024055671A1 (en) Vehicle control unit, motor control unit, and related device
KR20210080659A (en) Control apparatus and method of rear wheel steer
JP6329308B2 (en) Vehicle control apparatus and vehicle control method

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant
PE01 Entry into force of the registration of the contract for pledge of patent right

Denomination of invention: 4WD vehicle and its torque distribution method, device and storage medium

Effective date of registration: 20211213

Granted publication date: 20201215

Pledgee: BEIJING AUTOMOTIVE GROUP Co.,Ltd.

Pledgor: Borgward Automotive (China) Co., Ltd.

Registration number: Y2021990001167

PE01 Entry into force of the registration of the contract for pledge of patent right
PC01 Cancellation of the registration of the contract for pledge of patent right

Date of cancellation: 20231201

Granted publication date: 20201215

Pledgee: BEIJING AUTOMOTIVE GROUP Co.,Ltd.

Pledgor: Beijing baowo Automobile Co.,Ltd.|Borgward Automotive (China) Co., Ltd.

Registration number: Y2021990001167

PC01 Cancellation of the registration of the contract for pledge of patent right