Torque limiting method and apparatus

Abstract

The application relates to the technical field of torque control, and provides a torque limiting method and device. The method comprises the following steps: in the case that a vehicle is in a static state, determining that the rotating speed of a prime mover of the vehicle reaches a preset rotating speed, obtaining the first limit adhesion of each wheel of the vehicle according to the output torque of the prime mover; determining the first limit longitudinal moment corresponding to the wheel according to the first limit adhesion of the wheel and the wheel rotating angle of the wheel; determining the limit torque corresponding to each wheel according to the first limit longitudinal moment corresponding to each wheel; and limiting the output torque of the prime mover according to the limit torque corresponding to each wheel. The torque limiting method provided in the application can improve the safety of vehicle driving.

Description

Technical Field

[0001] This application relates to the field of torque control technology, specifically to a torque limiting method and device. Background Technology

[0002] With the development of vehicle technology, limiting the output torque of the vehicle's prime mover has become one of the important means to improve the vehicle's driving stability on different road surfaces.

[0003] In related technologies, torque limiting in vehicles typically involves the chassis controller determining the limiting torque and sending it to the vehicle controller, which then responds to the limiting torque by limiting the output torque of the prime mover. However, the chassis controller only determines and sends the limiting torque after the wheels have already slipped off the ground. Therefore, this torque limiting method cannot suppress slippage, thus affecting vehicle driving safety. Summary of the Invention

[0004] This application aims to address at least one of the technical problems existing in the related art. To this end, this application proposes a torque limiting method that can improve vehicle driving safety.

[0005] The torque limiting method according to the first aspect of this application includes: When the vehicle is stationary, the speed of the prime mover of the vehicle is determined to reach a preset speed, and the first limit adhesion force of each wheel in the vehicle is obtained based on the output torque of the prime mover. The first limiting longitudinal torque of the wheel is determined based on the first limiting adhesion force of the wheel and the wheel rotation angle. Based on the first limiting longitudinal moment corresponding to each wheel, determine the limiting torque corresponding to each wheel; The output torque of the prime mover is limited according to the limiting torque corresponding to each wheel; The preset rotational speed is the critical value at which the stationary vehicle will slip on the current road surface when the rotation angle of each wheel is zero.

[0006] By calculating the first limiting torque of the wheels based on the output torque of the prime mover when the vehicle is stationary and the prime mover reaches a set speed, the limiting torque corresponding to each wheel is determined based on the first limiting torque and the limiting longitudinal torque derived from the wheel rotation angle. This limiting torque restricts the output torque of the prime mover. Therefore, before the vehicle starts, the limiting torque of each wheel, matching the current road surface adhesion conditions, can be pre-calibrated based on the first limiting longitudinal torque of each wheel. This allows for preventative limiting of the prime mover's output torque during vehicle start-up, effectively suppressing wheel slippage and improving driving safety.

[0007] According to one embodiment of this application, determining the first limiting longitudinal moment corresponding to the wheel based on the first limiting adhesion force of the wheel and the wheel rotation angle includes: The first limit longitudinal adhesion force of the wheel is determined based on the first limit adhesion force of the wheel and the wheel rotation angle of the wheel; The first limiting longitudinal torque of the wheel is determined based on the first limiting longitudinal adhesion force of the wheel and the wheel radius.

[0008] According to one embodiment of this application, determining the limiting torque corresponding to each of the wheels based on the first limiting longitudinal torque corresponding to each wheel includes: Based on the first limiting longitudinal moment corresponding to each wheel and the yaw moment constraint determined based on the first limiting yaw moment corresponding to each wheel, the limiting torque corresponding to each wheel is determined. The first limiting yaw moment corresponding to the wheel is determined based on the first limiting lateral adhesion force of the wheel and the longitudinal distance from the wheel axle to the vehicle's center of gravity; the first limiting lateral adhesion force of the wheel is determined based on the first limiting adhesion force of the wheel and the wheel rotation angle.

[0009] According to one embodiment of this application, determining the limiting torque corresponding to each wheel based on the first limiting longitudinal moment corresponding to each wheel and the yaw moment constraint determined based on the first limiting yaw moment corresponding to each wheel includes: The initial limiting torque corresponding to the wheel is determined based on the first limiting longitudinal torque corresponding to the wheel. Based on the yaw moment constraint determined by the first limit yaw moment corresponding to each wheel, the initial limiting torque corresponding to each wheel is adjusted to obtain the limiting torque corresponding to each wheel.

[0010] According to one embodiment of this application, the method further includes: When the vehicle is in motion, it is determined that the wheel end slip ratio of the wheel reaches a preset slip ratio, and the second limit adhesion force of each wheel in the vehicle is obtained based on the output torque of the prime mover. The second limit longitudinal moment corresponding to the wheel is determined based on the second limit adhesion force of the wheel and the wheel rotation angle of the wheel. Based on the second limit longitudinal torque corresponding to each wheel, the limiting torque corresponding to each wheel is adjusted, so as to limit the output torque of the prime mover based on the adjusted limiting torque corresponding to each wheel.

[0011] According to one embodiment of this application, determining the second ultimate longitudinal moment corresponding to the wheel based on the second ultimate adhesion force of the wheel and the wheel rotation angle of the wheel includes: The adhesion coefficient of each wheel is determined based on the second limit adhesion force of the wheel. The third limiting adhesion force of each wheel is determined based on the adhesion coefficient of each wheel and the current vertical load of each wheel. The second limiting longitudinal torque corresponding to each wheel is determined based on the third limiting adhesion force of each wheel and the wheel rotation angle of each wheel.

[0012] According to one embodiment of this application, the method further includes: Based on the current travel change of the suspension corresponding to the wheel and the suspension tilt angle of the suspension corresponding to the wheel, determine the current vertical load change corresponding to the wheel; The current vertical load of the wheel is determined based on the static vertical load of the wheel when the vehicle is stationary, and the change in the current vertical load of the wheel.

[0013] The torque limiting method according to a second aspect embodiment of this application includes: When the vehicle is in motion, the wheel end slip ratio is determined to reach a preset slip ratio, and the second limit adhesion force of each wheel in the vehicle is obtained based on the output torque of the prime mover of the vehicle. The second limit longitudinal moment corresponding to the wheel is determined based on the second limit adhesion force of the wheel and the wheel rotation angle of the wheel. The limiting torque corresponding to each wheel is determined based on the second limit longitudinal torque corresponding to each wheel; The output torque of the prime mover is limited according to the limiting torque corresponding to each wheel.

[0014] The torque limiting device according to a third aspect embodiment of this application includes: The adhesion determination module is used to determine the speed of the prime mover of the vehicle when the vehicle is stationary, and to obtain the first limit adhesion force of each wheel in the vehicle based on the output torque of the prime mover. The torque determination module is used to determine the first limit longitudinal torque corresponding to the wheel based on the first limit adhesion force of the wheel and the wheel rotation angle of the wheel. The torque determination module is used to determine the limiting torque corresponding to each wheel based on the first limiting longitudinal torque corresponding to each wheel. A torque limiting module is used to limit the output torque of the prime mover according to the limiting torque corresponding to each wheel; The preset rotational speed is the critical value at which the stationary vehicle will slip on the current road surface when the rotation angle of each wheel is zero.

[0015] The torque limiting device according to the fourth aspect of this application includes: The adhesion acquisition module is used to determine when the wheel end slip ratio of the wheel reaches a preset slip ratio when the vehicle is in motion, and to obtain the second limit adhesion force of each wheel in the vehicle based on the output torque of the prime mover of the vehicle. The longitudinal torque determination module is used to determine the second limit longitudinal torque corresponding to the wheel based on the second limit adhesion force of the wheel and the wheel rotation angle of the wheel. The limiting torque acquisition module is used to determine the limiting torque corresponding to each wheel based on the second limiting longitudinal torque corresponding to each wheel. The output torque limiting module is used to limit the output torque of the prime mover according to the limiting torque corresponding to each wheel.

[0016] An electronic device according to a fifth aspect of this application includes a processor and a memory storing a computer program, wherein the processor executes the computer program to implement the torque limiting method described in any of the above embodiments.

[0017] A computer-readable storage medium according to a sixth aspect of this application stores a computer program thereon, which, when executed by a processor, implements the torque limiting method described in any of the above embodiments.

[0018] The vehicle according to the seventh aspect of this application includes electronic equipment as provided in the fifth aspect of the present application. Attached Figure Description

[0019] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments of this application will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the vehicle structure according to some embodiments of this application; Figure 2 This is a first flowchart illustrating the torque limiting method provided in an embodiment of this application; Figure 3 This is a second flowchart illustrating the torque limiting method provided in an embodiment of this application; Figure 4 A schematic diagram of the third process of the torque limiting method provided in the embodiments of this application; Figure 5 This is a first structural schematic diagram of the torque limiting device provided in the embodiments of this application; Figure 6 This is a schematic diagram of the second structure of the torque limiting device provided in the embodiments of this application; Figure 7 This is a schematic diagram of the structure of the electronic device provided in the embodiments of this application. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0022] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0023] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0024] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0025] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0026] In the description of the embodiments of this application, the term "multiple" refers to two or more (including two), and similarly, "multiple items" refers to two or more (including two).

[0027] The meanings of some specific terms used in the embodiments of this application are as follows: Ultimate adhesion refers to the maximum tire force that a vehicle can transmit to the road surface through its wheels under the current road surface conditions. It is used to characterize the upper limit of the adhesion that the current road surface can provide.

[0028] Longitudinal ultimate adhesion force refers to the component of the ultimate adhesion force in the direction of the wheel's rotation plane, and is used to characterize the maximum longitudinal force that the wheel can use for driving or braking under current working conditions.

[0029] Lateral limit adhesion refers to the component of the limit adhesion force perpendicular to the wheel's plane of rotation. It is used to characterize the maximum lateral force that the wheel can use for steering or resisting sideslip under current operating conditions.

[0030] The ultimate longitudinal torque refers to the maximum driving or braking torque that a wheel can exert under current road conditions. It is used to characterize the torque limit that the wheel can transmit about its axle axis.

[0031] The limiting yaw moment refers to the maximum yaw moment contribution of the wheel to the whole vehicle under the current road conditions. It is used to characterize the limit of the moment that the wheel can generate around the vertical axis of the whole vehicle.

[0032] The torque limiting method and apparatus provided in this application will be described in detail below through several specific embodiments.

[0033] With the development of vehicle technology, limiting the output torque of vehicle prime movers, such as electric motors and / or engines, to limit the maximum torque that the prime mover can output, has become one of the important means to improve the driving stability of vehicles on different road surfaces.

[0034] In related technologies, torque limiting for vehicles typically involves the chassis controller determining the limiting torque and sending it to the vehicle controller, which then responds to the limiting torque by limiting the output torque of the prime mover. However, the chassis controller only determines and sends the limiting torque after the wheels have already slipped off the ground. Therefore, this torque limiting method is a remedial measure when vehicle slippage occurs; it cannot suppress slippage and thus cannot effectively prevent slippage when starting on surfaces with low traction, affecting vehicle driving safety.

[0035] Therefore, this embodiment of the application, when the vehicle is stationary, if the prime mover's rotational speed reaches a set value, then the first limit adhesion force of the wheels is calculated based on the prime mover's output torque at that time. Based on this first limit adhesion force and the limit longitudinal torque derived from the wheel rotation angle, the corresponding limiting torque for each wheel is determined, thereby limiting the prime mover's output torque. Thus, before the vehicle starts, the limiting torque for each wheel, matching the current road surface adhesion conditions, can be pre-calibrated based on the first limit longitudinal torque of each wheel. This allows for preventative limiting of the prime mover's output torque during vehicle start-up, effectively suppressing wheel slippage and improving driving safety.

[0036] The torque limiting method disclosed in this application can be applied to vehicles. The vehicle can be a gasoline-powered vehicle, a natural gas-powered vehicle, or a new energy vehicle; the new energy vehicle can be a pure electric vehicle, a hybrid electric vehicle, or a range-extended vehicle, etc.

[0037] For ease of explanation, the following examples are provided. Figure 1 Let's take vehicle 10, a new energy vehicle, as an example for explanation. Figure 1 As shown, vehicle 10 includes battery pack 100, controller 200, and prime mover 300. Battery pack 100 can be used to power vehicle 10; for example, battery pack 100 can serve as the operating power source for vehicle 10. Controller 200 can be a VCU (Vehicle Control Unit), and prime mover 300 can be an electric motor. Controller 200 is used to control the output torque of prime mover 300, for example, by controlling the output torque of the electric motor through a motor controller.

[0038] According to some embodiments of this application, this application provides a torque limiting method, which can be applied to the aforementioned vehicle, specifically to a controller mounted on the vehicle, for limiting the output torque of the vehicle's prime mover. Figure 2 As shown, the torque limiting method provided in this embodiment includes: S101, when the vehicle is stationary, determine that the speed of the prime mover of the vehicle has reached a preset speed, and obtain the first limit adhesion force of each wheel in the vehicle based on the output torque of the prime mover. S102, Based on the first ultimate adhesion force of the wheel and the wheel rotation angle, determine the first ultimate longitudinal torque corresponding to the wheel; S103, determine the limiting torque corresponding to each wheel based on the first limiting longitudinal torque corresponding to each wheel; S104, the output torque of the prime mover is limited according to the limiting torque corresponding to each wheel; The preset rotational speed is the critical value at which the stationary vehicle will slip on the current road surface when the rotation angle of each wheel is zero.

[0039] In some embodiments, the critical speed value that causes a stationary vehicle to slip on the current road surface refers to the minimum speed at which the prime mover can cause the stationary vehicle to slip on the current road surface. When the vehicle is stationary, if the speed of the prime mover reaches the critical speed value, it will cause the vehicle to slip on the current road surface. This critical speed value can be set according to actual conditions. For example, through numerous experiments, the critical speed values ​​of the prime mover corresponding to different road surfaces can be calibrated when the vehicle is stationary and the wheel angles of all its wheels are zero. When the vehicle is currently stationary, the corresponding critical speed value can be determined as the preset speed of the prime mover based on the current road surface on which the vehicle is located. For example, the preset speed can be 80 rpm.

[0040] When the vehicle is stationary, if the prime mover's speed reaches a preset speed, the output torque of the prime mover at this point is the maximum torque requested by the vehicle controller from the prime mover when the vehicle is not steering on this road surface; that is, the maximum output torque controlled by the prime mover. At this time, the adhesion between the wheels and the ground is the ultimate adhesion force. Based on this, when the prime mover's speed reaches the preset speed, the first ultimate adhesion force of each wheel in the vehicle can be deduced from the output torque of the prime mover at this point. For example, the first ultimate adhesion force of each wheel in the vehicle... for: ;in, The output torque of the prime mover is given when the prime mover speed is at a preset speed; i is the transmission ratio; and r represents the wheel radius.

[0041] Since the preset rotational speed is the critical speed at which a stationary vehicle will slip on the current road surface when the steering angle of each wheel is zero, the first limiting adhesion force of the wheel, obtained based on the output torque of the prime mover corresponding to this preset rotational speed, is the maximum longitudinal adhesion force that the wheel can transmit in a pure longitudinal slip state. This accurately characterizes the ultimate adhesion capability that the current road surface can provide in all directions. Therefore, this first limiting adhesion force can be used as an isotropic adhesion limit benchmark for subsequently determining the first limiting longitudinal torque corresponding to the wheel based on the wheel's steering angle, thus ensuring the accuracy of the first limiting longitudinal torque.

[0042] Based on the obtained first ultimate adhesion force of the wheel and the wheel angle, a target data set consisting of the first ultimate adhesion force and the wheel angle can be obtained. Based on this target data set, the ultimate longitudinal torque corresponding to the target data set is obtained from a record table that records the mapping relationship between each data set and each ultimate longitudinal torque, and is used as the first ultimate longitudinal torque corresponding to the wheel. The mapping relationship between each data set in the record table and each ultimate longitudinal moment can be obtained through experimental testing. The first limiting longitudinal torque corresponding to the nth wheel.

[0043] The first limiting longitudinal moment for any wheel From this, we can deduce the limit torque corresponding to that wheel. .in, This represents the limit torque corresponding to the nth wheel. By using the limit torques corresponding to each wheel, the maximum requested torque allowed by the controller can be determined, and the output torque of the prime mover can be limited based on this maximum requested torque.

[0044] For example, if each wheel of the vehicle is independently driven, the maximum requested torque allowed by the controller for the nth wheel is the limit torque corresponding to that wheel, i.e., the maximum requested torque. Where n represents the nth wheel, and N represents the number of wheels. After obtaining the maximum requested torque for each wheel, for a given wheel, its maximum requested torque can be used as the maximum allowable output torque of the prime mover driving that wheel, ensuring that the prime mover's output torque is less than or equal to this maximum torque. If the vehicle's wheels are all centrally driven on a single axle, such as front-wheel drive or rear-wheel drive, then the maximum requested torque allowed by the controller is twice the minimum value of the limit torques corresponding to the left and right wheels on the same axle. That is, the maximum requested torque. .in, This indicates the maximum torque corresponding to the left wheel on the same axle. This indicates the limit torque corresponding to the right wheel on the same axle.

[0045] By calculating the first limiting torque of the wheels based on the output torque of the prime mover when the vehicle is stationary and the prime mover reaches a set speed, the limiting torque corresponding to each wheel is determined based on the first limiting torque and the limiting longitudinal torque derived from the wheel rotation angle. This limiting torque restricts the output torque of the prime mover. Therefore, before the vehicle starts, the limiting torque of each wheel, matching the current road surface adhesion conditions, can be pre-calibrated based on the first limiting longitudinal torque of each wheel. This allows for preventative limiting of the prime mover's output torque during vehicle start-up, effectively suppressing wheel slippage and improving driving safety.

[0046] Considering the first limiting longitudinal moment corresponding to the wheel, it can be obtained by looking up a table using the wheel's first limiting adhesion force and the wheel's rotation angle. To avoid situations where the corresponding data is missing from the record table, such as the first limiting longitudinal moment, it is necessary to add as many verified data sets and their mapping relationships to the limiting longitudinal moments as possible to the mapping table. However, since the record table cannot exhaust all data, there will still be cases where the first limiting longitudinal moment corresponding to the wheel cannot be determined by searching the record table.

[0047] Therefore, in some embodiments, the first limiting longitudinal moment corresponding to the wheel is determined based on the first limiting adhesion force of the wheel and the wheel rotation angle, including: The first limit longitudinal adhesion force of the wheel is determined based on the first limit adhesion force of the wheel and the wheel rotation angle of the wheel; The first limiting longitudinal torque of the wheel is determined based on the first limiting longitudinal adhesion force of the wheel and the wheel radius.

[0048] In some embodiments, the first ultimate adhesion force of the wheel can be obtained based on the first ultimate adhesion force of the wheel. And the wheel's turning angle θ, for the first limiting adhesion force Force decomposition was performed to determine the first limiting longitudinal adhesion force of the wheel. for: .

[0049] Based on the first ultimate longitudinal adhesion force of the wheel Given the known wheel radius r, the first limiting longitudinal torque of the wheel can be obtained. for: Therefore, the first ultimate longitudinal adhesion force of the wheel can be deduced from its first ultimate adhesion force. Based on this first ultimate longitudinal adhesion force and the known wheel radius, the corresponding first ultimate longitudinal moment of the wheel can be calculated. This eliminates the need to consult a record table to determine the corresponding first ultimate longitudinal moment of the wheel, avoiding situations where the corresponding first ultimate longitudinal moment of the wheel cannot be determined.

[0050] Considering that if the limiting torque of each wheel is determined solely based on the first limiting longitudinal moment corresponding to each wheel to limit the output torque of the prime mover, a large torque difference may occur between the left and right wheels during the vehicle's initial large steering or under conditions of uneven adhesion between the two wheels, potentially leading to vehicle slippage. Therefore, in some embodiments, the limiting torque corresponding to each wheel is determined based on the first limiting longitudinal moment corresponding to each wheel, including: Based on the first limiting longitudinal moment corresponding to each wheel and the yaw moment constraint determined based on the first limiting yaw moment corresponding to each wheel, the limiting torque corresponding to each wheel is determined. The first limiting yaw moment corresponding to the wheel is determined based on the first limiting lateral adhesion force of the wheel and the longitudinal distance from the wheel axle to the vehicle's center of gravity; the first limiting lateral adhesion force of the wheel is determined based on the first limiting adhesion force of the wheel and the wheel rotation angle.

[0051] In some embodiments, based on the wheel's first ultimate adhesion force And the wheel's turning angle θ, for the first limiting adhesion force Force decomposition is performed to determine the corresponding limiting longitudinal adhesion force and limiting lateral adhesion force. The limiting longitudinal adhesion force is the first limiting longitudinal adhesion force of the wheel. This ultimate lateral adhesion force is the first ultimate lateral adhesion force of the wheel. The first limiting lateral adhesion force for: = .

[0052] Based on the first ultimate longitudinal adhesion force of the decomposed wheel The first limiting longitudinal torque corresponding to the wheel can be calculated. Simultaneously, based on the decomposed first limit lateral adhesion force of the wheel. Given the known longitudinal distance from the axle where the wheel is located to the vehicle's center of gravity, the first limiting yaw moment corresponding to that wheel can be calculated. .Right now Among them, l n Let n be the longitudinal distance from the axle where wheel n is located to the center of mass of the vehicle.

[0053] For the first limiting yaw moment corresponding to each wheel It can be based on the first limiting yaw moment corresponding to each wheel. This is used to determine the yaw moment constraint. For example, when the vehicle is stationary, the first limiting yaw moments corresponding to each wheel can be added together to obtain the sum of the first limiting yaw moments. This sum of the first limiting yaw moments is the upper limit of the yaw moment generated by the vehicle through lateral force energy. .Right now: Where n = 1, 2, …, N, and N represents the number of wheels. This represents the first limiting yaw moment corresponding to the nth wheel. Based on this upper limit of yaw moment... The yaw moment constraint can then be determined. If the upper limit of the yaw moment is... As a constraint of yaw moment .

[0054] In some embodiments, determining the limiting torque corresponding to each wheel based on the first limiting longitudinal moment corresponding to each wheel and the yaw moment constraint determined based on the first limiting yaw moment corresponding to each wheel can be: Based on the first ultimate longitudinal torque corresponding to each wheel The longitudinal limit constraint conditions can be obtained as follows: . This represents the driving torque allocated to the nth wheel.

[0055] Based on yaw moment constraint The lateral limit constraint conditions can be obtained as follows:

[0056] in, and These represent the driving torque of the left and right wheels on the same axle, respectively. This indicates the wheelbase between the left and right wheels on the same axle.

[0057] Alternatively, the first limiting yaw moment corresponding to each wheel can be directly determined as the lateral limiting constraint condition corresponding to each wheel.

[0058] Based on the longitudinal limit constraints, the limiting torque corresponding to each wheel can be determined. For example, by taking maximizing the limiting torque of each wheel as the objective function and applying the longitudinal limit constraints, the limiting torque corresponding to each wheel can be obtained.

[0059] Alternatively, in some embodiments, the limiting torque corresponding to each wheel is determined based on the first limiting longitudinal moment corresponding to each wheel and the yaw moment constraint determined based on the first limiting yaw moment corresponding to each wheel, including: The initial limiting torque corresponding to the wheel is determined based on the first limiting longitudinal torque corresponding to the wheel. Based on the yaw moment constraint determined by the first limit yaw moment corresponding to each wheel, the initial limiting torque corresponding to each wheel is adjusted to obtain the limiting torque corresponding to each wheel.

[0060] In some embodiments, the first limiting longitudinal torque corresponding to any wheel n The corresponding limit torque can be derived by first working backward. This serves as the initial limiting torque for that wheel.

[0061] After obtaining the initial limiting torque for each wheel, it can be combined with yaw moment constraints. The obtained lateral limit constraints are used to determine whether the initial limiting torque for each wheel satisfies these constraints. If it does, the initial limiting torque for each wheel is used as its corresponding limiting torque. If the initial limiting torque for at least one wheel does not satisfy the lateral limit constraints, the initial limiting torque for that wheel is adjusted with the objective function of maximizing its limiting torque, until it satisfies the lateral limit constraints. The adjusted initial limiting torque is then used as the limiting torque for that wheel. This reduces the computational complexity of the algorithm while ensuring that the final limiting torque for each wheel meets the requirements of longitudinal adhesion limits and yaw stability, facilitating real-time adjustment of the limiting torque.

[0062] By determining the limiting torque for each wheel based on the first limiting longitudinal torque corresponding to each wheel and the yaw moment constraint based on the first limiting yaw moment corresponding to each wheel, the limiting torque for each wheel can meet the requirements of longitudinal adhesion limit and yaw stability, thus avoiding the situation where the vehicle slips due to excessive torque difference between the left and right wheels, and further suppressing wheel slip that may occur when the vehicle starts, thereby further improving driving safety.

[0063] To further improve vehicle driving safety, in some embodiments, the method further includes: When the vehicle is in motion, it is determined that the wheel end slip ratio of the wheel reaches a preset slip ratio, and the second limit adhesion force of each wheel in the vehicle is obtained based on the output torque of the prime mover. The second limit longitudinal moment corresponding to the wheel is determined based on the second limit adhesion force of the wheel and the wheel rotation angle of the wheel. Based on the second limit longitudinal torque corresponding to each wheel, the limiting torque corresponding to each wheel is adjusted, so as to limit the output torque of the prime mover based on the adjusted limiting torque corresponding to each wheel.

[0064] In some embodiments, a critical slip ratio value that causes a moving vehicle to slip on the current road surface can be determined through extensive testing or vehicle slip ratio curves, and this value can be used as a preset slip ratio. When the vehicle is in motion, if the wheel end slip ratio reaches this preset slip ratio, the vehicle will slip on the current road surface. For example, the preset slip ratio can range from 15% to 20%, such as 17.5%.

[0065] In some embodiments, when the vehicle is in motion, the wheel end slip ratio can be obtained based on the acquired vehicle speed, tire angular velocity, and tire radius: .in, This indicates the wheel end slip ratio. This represents the angular velocity of the wheel's tires. This indicates the tire radius of the wheel. This indicates the vehicle's speed.

[0066] If the wheel-end slip ratio of any wheel in the vehicle is detected to reach a preset slip ratio, it is assumed that the wheel will slip with the ground. At this point, the second limiting adhesion force of each wheel in the vehicle is deduced based on the output torque of the prime mover when the wheel-end slip ratio reaches the preset slip ratio. For example, the second limiting adhesion force of each wheel in the vehicle... for: ;in, The output torque of the prime mover is given when the wheel end slip ratio reaches the preset slip ratio; i is the transmission ratio; r represents the wheel radius.

[0067] Based on the obtained second-limit adhesion force of the wheel and the current wheel angle, a target data set consisting of the second-limit adhesion force and the wheel angle can be obtained. Based on this target data set, the limiting longitudinal torque corresponding to the target data set is obtained from a record table that records the mapping relationship between each data set and each limiting longitudinal torque, and is used as the second-limit longitudinal torque corresponding to the wheel. .

[0068] In some embodiments, the second limit adhesion of the wheel can be used as a basis. And the wheel's turning angle θ, for the second limiting adhesion force Force decomposition was performed to determine the second ultimate longitudinal adhesion force of the wheel. for: Based on the second ultimate longitudinal adhesion of the wheel. Given the known wheel radius r, the second limiting longitudinal moment of the wheel can be obtained. for: .

[0069] The second limiting longitudinal moment for any wheel This allows us to deduce the current maximum torque value corresponding to that wheel. This allows for the adjustment of the wheel's corresponding limit torque based on the current limit torque value. For example, updating the wheel's corresponding limit torque based on the current limit torque value.

[0070] After adjusting the limit torque for each wheel, the controller can adjust the maximum requested torque based on the adjusted limit torque for each wheel. This adjusted maximum requested torque is then used as the maximum torque allowed to be output by the prime mover. The output torque of the prime mover is then limited based on this maximum torque, ensuring that the output torque of the prime mover is less than or equal to this maximum torque.

[0071] By calculating the second limiting torque of each wheel based on its output torque while the vehicle is in motion, when the wheel slip ratio reaches a preset slip ratio, the system calculates the second limiting adhesion force of the wheel based on the output torque of the prime mover. Then, based on this second limiting adhesion force and the limiting longitudinal torque determined by the wheel rotation angle, the corresponding limiting torque of each wheel is adjusted. This adjusted limiting torque of each wheel restricts the output torque of the prime mover. Therefore, during vehicle operation, the limiting torque of each wheel can be adjusted to match the current road surface adhesion conditions based on the second limiting longitudinal torque of each wheel. This allows for preventative limiting of the prime mover's output torque even while the vehicle is in motion, effectively suppressing wheel slip and further improving driving safety.

[0072] Considering that, based on the friction ellipse theory, the adhesion between a wheel and the ground is affected by the vertical load of the wheel, where the vertical load refers to the reaction force exerted on the wheel by the ground through the wheel in a direction perpendicular to the road surface. When the vehicle is in motion, changes in turning angle or speed will cause a shift in its center of gravity, resulting in changes in the vertical load of each wheel. Therefore, directly determining the second limiting longitudinal moment based on the second limiting adhesion force and wheel rotation angle to adjust the corresponding limiting torque may lead to inconsistencies between the second limiting adhesion force and the actual limiting adhesion force due to significant changes in the vertical load of each wheel. This could affect the reliability of the adjusted limiting torque and consequently impact vehicle safety. Therefore, in some embodiments, the second limiting longitudinal moment corresponding to the wheel is determined based on the second limiting adhesion force and the wheel rotation angle, including: The adhesion coefficient of each wheel is determined based on the second limit adhesion force of the wheel. The third limiting adhesion force of each wheel is determined based on the adhesion coefficient of each wheel and the current vertical load of each wheel. The second limiting longitudinal torque corresponding to each wheel is determined based on the third limiting adhesion force of each wheel and the wheel rotation angle of each wheel.

[0073] In some embodiments, the second limit adhesion force of the obtained wheel can be based on the adhesion force calculation formula. The adhesion coefficient μ of the wheel is determined. Here, m represents the vehicle's total mass, and g represents gravitational acceleration. Furthermore, the current vertical load on the wheel can be obtained using sensors installed on the wheel, such as a gravity sensor.

[0074] Based on the adhesion coefficient of a certain wheel and its current vertical load, and using the friction ellipse theory, the third limiting adhesion force of the wheel can be obtained as follows: The third limit of adhesion force obtained at this point is the actual limit of adhesion force between the wheel and the current road surface.

[0075] After obtaining the third limiting adhesion force of the wheel, a target data set consisting of the third limiting adhesion force and the wheel's current rotation angle can be obtained. Based on this target data set, the limiting longitudinal torque corresponding to the target data set can be obtained from a record table that records the mapping relationship between each data set and each limiting longitudinal torque, and this limiting longitudinal torque is taken as the second limiting longitudinal torque for the wheel. .

[0076] Alternatively, it can be based on the third limit of adhesion of the wheel. And the wheel's turning angle θ, for the second limiting adhesion force Force decomposition is performed to obtain the second limiting longitudinal adhesion force of the wheel, and based on the second limiting longitudinal adhesion force and the wheel radius, the corresponding second limiting longitudinal torque of the wheel is obtained.

[0077] By determining the adhesion coefficient of each wheel based on its second ultimate adhesion force, and then determining the third ultimate adhesion force of each wheel based on its adhesion coefficient and current vertical load, the corresponding second ultimate longitudinal moment of each wheel is determined based on its third ultimate adhesion force and wheel rotation angle. This allows the ultimate adhesion force of the wheels to be corrected by the vertical load, ensuring that the obtained second ultimate longitudinal moment takes into account the influence of the vehicle's center of gravity shift during movement. This makes the limiting torque obtained using the second ultimate longitudinal moment more closely reflect actual conditions, thereby further improving vehicle driving safety.

[0078] To more accurately determine the current vertical load of each wheel, thereby improving the accuracy of the obtained third-limit adhesion force and further enhancing vehicle driving safety, in some embodiments, the method further includes: Based on the current travel change of the suspension corresponding to the wheel and the suspension tilt angle of the suspension corresponding to the wheel, determine the current vertical load change corresponding to the wheel; The current vertical load of the wheel is determined based on the static vertical load of the wheel when the vehicle is stationary, and the change in the current vertical load of the wheel.

[0079] In some embodiments, when it is necessary to obtain the current vertical load of a wheel, the current travel change δ of the suspension supporting the wheel can be obtained through a sensor, along with the known suspension stiffness E, to obtain the stress corresponding to the wheel. Based on the stress corresponding to the wheel and the suspension camber angle of the suspension supporting the wheel. The change in the current vertical load corresponding to this wheel can be obtained as follows: .

[0080] Combined with the current vertical load change corresponding to the wheel And the static vertical load of the wheel recorded when the vehicle is stationary. The current vertical load on the wheel can be obtained as follows: .

[0081] After determining the current vertical load on the wheel, the third limiting adhesion force of the wheel can be determined based on its adhesion coefficient and current vertical load. Using a target data set composed of the third limiting adhesion force and the wheel's rotation angle, the limiting longitudinal moment corresponding to the target data set is obtained from a record table that records the mapping relationship between each data set and each limiting longitudinal moment, and this limiting longitudinal moment is taken as the second limiting longitudinal moment corresponding to the wheel.

[0082] Alternatively, in some embodiments, the second limiting longitudinal moment corresponding to each wheel is determined based on the third limiting adhesion force of each wheel and the wheel rotation angle, including: The second limit longitudinal adhesion force of the wheel is determined based on the third limit adhesion force of the wheel and the wheel rotation angle. The second limiting longitudinal torque of the wheel is determined based on the second limiting longitudinal adhesion force of the wheel and the wheel radius.

[0083] In some embodiments, the obtained third limit adhesion force of the wheel can be based on the third limit adhesion force of the wheel. And the wheel's turning angle θ, for the third limiting adhesion force Force decomposition was performed to determine the second ultimate longitudinal adhesion force of the wheel. for: .

[0084] Based on the second ultimate longitudinal adhesion force of the wheel Given the known wheel radius r, the second limiting longitudinal moment of the wheel can be obtained. for: Therefore, the second ultimate longitudinal adhesion force of the wheel can be deduced from its third ultimate adhesion force. Based on this second ultimate longitudinal adhesion force and the known wheel radius, the corresponding second ultimate longitudinal torque can be calculated. This eliminates the need to consult a record table to determine the second ultimate longitudinal torque, avoiding situations where the second ultimate longitudinal torque cannot be determined, and improving the efficiency of obtaining the second ultimate longitudinal torque.

[0085] To further improve driving safety, in some embodiments, the limiting torque corresponding to each wheel is adjusted according to the second limiting longitudinal torque corresponding to each wheel, including: Adjust the limiting torque corresponding to each wheel according to the second limit longitudinal torque corresponding to each wheel and the yaw moment constraint determined based on the second limit yaw moment corresponding to each wheel; The second limiting yaw moment corresponding to the wheel is determined based on the second limiting lateral adhesion force of the wheel and the longitudinal distance from the wheel axle to the vehicle's center of gravity; the second limiting lateral adhesion force of the wheel is determined based on the third limiting adhesion force of the wheel and the wheel rotation angle.

[0086] In some embodiments, based on the third limit adhesion of the wheel And the wheel's turning angle θ, for the third limiting adhesion force Force decomposition is performed to determine the corresponding limiting longitudinal adhesion force and limiting lateral adhesion force. The limiting longitudinal adhesion force is the second limiting longitudinal adhesion force of the wheel. This ultimate lateral adhesion force is the second ultimate lateral adhesion force of the wheel. The second limit of lateral adhesion. for: = .

[0087] Based on the second ultimate longitudinal adhesion force of the decomposed wheel The second limiting longitudinal moment corresponding to the wheel can be calculated. Simultaneously, based on the decomposed second-limit lateral adhesion force of the wheel. Given the known longitudinal distance from the axle where the wheel is located to the vehicle's center of gravity, the second limiting yaw moment corresponding to that wheel can be calculated. .Right now .in, Let n be the longitudinal distance from the axle where wheel n is located to the vehicle's center of mass. This represents the second limit yaw moment corresponding to the nth wheel.

[0088] For the second limit yaw moment corresponding to each wheel It can be based on the second limit yaw moment corresponding to each wheel. This is used to determine the yaw moment constraint. For example, when the vehicle is in motion, the second-limit yaw moments corresponding to each wheel can be added together to obtain the sum of the second-limit yaw moments. This sum of second-limit yaw moments is the upper limit of the yaw moment generated by the vehicle through lateral force energy. .Right now: Where n = 1, 2, …, N, and N represents the number of wheels. Based on this upper limit of the yaw moment… This allows us to obtain the yaw moment constraint determined based on the second limit yaw moment corresponding to each wheel. If the upper limit of the yaw moment is... As a constraint of yaw moment .

[0089] Considering the influence of vertical load changes when the vehicle is in motion, the second limiting longitudinal adhesion force of different wheels may differ. Therefore, after obtaining the upper limit of the yaw moment... Then, the yaw moment generated by the longitudinal force difference between the left and right wheels on the same axle can be combined. This is used to obtain the yaw moment constraint determined based on the second limit yaw moment corresponding to each wheel. .Right now for: ; in, , This represents the second limiting longitudinal adhesion force of the left wheel within the same axle. This represents the second ultimate longitudinal adhesion force of the right wheel on the same axle.

[0090] In some embodiments, the limiting torque corresponding to each wheel is determined based on the second limiting longitudinal moment corresponding to each wheel and the yaw moment constraint determined based on the second limiting yaw moment corresponding to each wheel. This can be achieved by: Based on the second ultimate longitudinal moment corresponding to each wheel The longitudinal limit constraint conditions can be obtained as follows: . This represents the driving torque allocated to the nth wheel.

[0091] Based on yaw moment constraint The lateral limit constraint conditions can be obtained as follows: .

[0092] Alternatively, the second limiting yaw moment corresponding to each wheel can be directly determined as the lateral limit constraint condition corresponding to each wheel.

[0093] Based on the longitudinal limit constraints, the limiting torque corresponding to each wheel can be determined. If maximizing the limiting torque of each wheel is taken as the objective function, and constraints are applied using the longitudinal limit constraints, the limiting torque corresponding to each wheel when the vehicle is in motion can be adjusted.

[0094] Alternatively, in some embodiments, the second limiting longitudinal torque is applied to any wheel n. The corresponding limit torque value can be derived by first working backward. Based on this limit torque value, the limiting torque corresponding to the wheel is initially adjusted to obtain the limiting torque of the wheel after the initial adjustment.

[0095] After obtaining the limiting torque after the initial adjustment of each wheel, it can be combined with the yaw moment constraint. The obtained lateral limit constraints are used to determine whether the initial adjusted limiting torque of each wheel meets the lateral limit constraints. If it does, the initial adjusted limiting torque of each wheel can be used as the adjusted limiting torque of each wheel. If the initial adjusted limiting torque of at least one wheel does not meet the lateral limit constraints, the limiting torque of that wheel is further adjusted with the objective function of maximizing the limiting torque of that wheel until the adjusted limiting torque of that wheel meets the lateral limit constraints. The limiting torque obtained at this time is then used as the limiting torque corresponding to that wheel.

[0096] By adjusting the limiting torque corresponding to each wheel based on the second limit longitudinal torque corresponding to each wheel and the yaw moment constraint determined based on the second limit yaw moment corresponding to each wheel, the limiting torque of each wheel can still meet the longitudinal adhesion limit and yaw stability requirements when the vehicle is in continuous motion. This avoids the situation where the vehicle slips due to excessive torque difference between the left and right wheels, and further suppresses wheel slip that may occur when the vehicle starts, thereby further improving driving safety.

[0097] To make the objectives, technical solutions, and advantages of this application clearer, an embodiment of this application will be clearly and completely described below. In some embodiments, such as Figure 3As shown, the torque limiting method includes: S201, when the vehicle is stationary, determine that the speed of the prime mover of the vehicle has reached the preset speed, and obtain the first limit adhesion force of each wheel in the vehicle based on the output torque of the prime mover.

[0098] The preset rotational speed is the critical value at which a stationary vehicle will slip on the current road surface when the rotation angle of each wheel is zero.

[0099] S202, determine the first limit longitudinal adhesion of the wheel based on the first limit adhesion of the wheel and the wheel rotation angle.

[0100] S203, determine the first ultimate longitudinal torque of the wheel based on the first ultimate longitudinal adhesion force of the wheel and the wheel radius.

[0101] S204, determine the initial limiting torque corresponding to the wheel based on the first limiting longitudinal torque corresponding to the wheel.

[0102] S205, based on the yaw moment constraint determined by the first limit yaw moment corresponding to each wheel, adjust the initial limiting torque corresponding to each wheel to obtain the limiting torque corresponding to each wheel.

[0103] The first limiting yaw moment of the wheel is determined based on the first limiting lateral adhesion of the wheel and the longitudinal distance from the wheel axle to the vehicle's center of gravity; the first limiting lateral adhesion of the wheel is determined based on the first limiting adhesion of the wheel and the wheel's rotation angle.

[0104] S206 limits the output torque of the prime mover based on the limiting torque corresponding to each wheel.

[0105] S207, when the vehicle is in motion, determines that the wheel end slip ratio reaches the preset slip ratio, and obtains the second limit adhesion force of each wheel in the vehicle based on the output torque of the prime mover.

[0106] S208, determine the adhesion coefficient of each wheel based on the second limit adhesion of the wheel.

[0107] S209, determine the third limit adhesion force of each wheel based on the adhesion coefficient of each wheel and the current vertical load of each wheel.

[0108] The determination of the current vertical load of the wheel includes: determining the change in the current vertical load of the wheel based on the change in the current travel of the suspension corresponding to the wheel and the suspension tilt angle of the suspension corresponding to the wheel; and determining the current vertical load of the wheel based on the static vertical load of the wheel when the vehicle is stationary and the change in the current vertical load of the wheel.

[0109] S210, the second limit longitudinal adhesion of the wheel is determined based on the third limit adhesion of the wheel and the wheel rotation angle.

[0110] S211, based on the second limit longitudinal adhesion force of the wheel and the wheel radius, determine the corresponding second limit longitudinal torque of the wheel.

[0111] S212, adjust the limiting torque corresponding to each wheel according to the second limit longitudinal torque corresponding to each wheel and the yaw moment constraint determined based on the second limit yaw moment corresponding to each wheel.

[0112] The second limiting yaw moment of the wheel is determined based on the second limiting lateral adhesion force of the wheel and the longitudinal distance from the wheel axle to the vehicle's center of gravity; the second limiting lateral adhesion force of the wheel is determined based on the third limiting adhesion force of the wheel and the wheel's rotation angle.

[0113] In some embodiments, such as Figure 4 As shown, a torque limiting method is also provided, comprising: S301, when the vehicle is in motion, determine that the wheel end slip ratio of the wheel reaches the preset slip ratio, and obtain the second limit adhesion force of each wheel in the vehicle based on the output torque of the prime mover of the vehicle.

[0114] The specific method for obtaining the second limit adhesion force of each wheel in the vehicle based on the output torque of the vehicle's prime mover can be the same as the method described above, and will not be elaborated further here.

[0115] S302, based on the second limit adhesion force of the wheel and the wheel rotation angle, determine the second limit longitudinal torque corresponding to the wheel.

[0116] The specific method for determining the second limit longitudinal torque of the wheel based on the second limit adhesion force and the wheel rotation angle can be the same as the method described above, and will not be elaborated here.

[0117] S303, determine the limiting torque corresponding to each wheel based on the second limiting longitudinal torque corresponding to each wheel.

[0118] The specific method for determining the limiting torque corresponding to each wheel based on the second limit longitudinal torque corresponding to each wheel can be the same as the specific method for adjusting the limiting torque corresponding to each wheel based on the second limit longitudinal torque corresponding to each wheel, and will not be elaborated here.

[0119] S304, the output torque of the prime mover is limited according to the limiting torque corresponding to each wheel.

[0120] The specific method for limiting the output torque of the prime mover based on the limiting torque corresponding to each wheel can be the same as the method described above, and will not be elaborated here.

[0121] Figure 5 A first structural schematic diagram of a torque limiting device provided in this application is shown. It should be understood that this device is related to... Figure 2 The method embodiment executed in this document corresponds to the steps involved in the aforementioned method. The specific functions of this device can be found in the description above; to avoid repetition, detailed descriptions are omitted here. This device includes at least one software functional module that can be stored in memory or embedded in the device's operating system (OS) in the form of software or firmware. Specifically, this device is applied to a vehicle, and can be applied to a vehicle-mounted controller, such as a vehicle controller, for limiting the output torque of the vehicle's prime mover. The device includes: an adhesion determination module 410, used to determine when the vehicle's prime mover reaches a preset speed when the vehicle is stationary, and to obtain the first limit adhesion force of each wheel in the vehicle based on the output torque of the prime mover; a torque determination module 420, used to determine the first limit longitudinal torque corresponding to each wheel based on the first limit adhesion force of the wheel and the wheel angle of the wheel; a torque determination module 430, used to determine the limiting torque corresponding to each wheel based on the first limit longitudinal torque corresponding to each wheel; and a torque limiting module 440, used to limit the output torque of the prime mover based on the limiting torque corresponding to each wheel; wherein, the preset speed is the critical speed value that causes the stationary vehicle to slip on the current road surface when the wheel angle is zero.

[0122] By calculating the first limiting torque of the wheels based on the output torque of the prime mover when the vehicle is stationary and the prime mover reaches a set speed, the limiting torque corresponding to each wheel is determined based on the first limiting torque and the limiting longitudinal torque derived from the wheel rotation angle. This limiting torque restricts the output torque of the prime mover. Therefore, before the vehicle starts, the limiting torque of each wheel, matching the current road surface adhesion conditions, can be pre-calibrated based on the first limiting longitudinal torque of each wheel. This allows for preventative limiting of the prime mover's output torque during vehicle start-up, effectively suppressing wheel slippage and improving driving safety.

[0123] In one embodiment, the torque determination module 420 is specifically used for: The first limit longitudinal adhesion force of the wheel is determined based on the first limit adhesion force of the wheel and the wheel rotation angle of the wheel; The first limiting longitudinal torque of the wheel is determined based on the first limiting longitudinal adhesion force of the wheel and the wheel radius.

[0124] In one embodiment, the torque limiting module 440 is specifically used for: Based on the first limiting longitudinal moment corresponding to each wheel and the yaw moment constraint determined based on the first limiting yaw moment corresponding to each wheel, the limiting torque corresponding to each wheel is determined. The first limiting yaw moment corresponding to the wheel is determined based on the first limiting lateral adhesion force of the wheel and the longitudinal distance from the wheel axle to the vehicle's center of gravity; the first limiting lateral adhesion force of the wheel is determined based on the first limiting adhesion force of the wheel and the wheel rotation angle.

[0125] In one embodiment, the torque limiting module 440 is specifically used for: The initial limiting torque corresponding to the wheel is determined based on the first limiting longitudinal torque corresponding to the wheel. Based on the yaw moment constraint determined by the first limit yaw moment corresponding to each wheel, the initial limiting torque corresponding to each wheel is adjusted to obtain the limiting torque corresponding to each wheel.

[0126] In one embodiment, the torque limiting module 440 is further configured to: When the vehicle is in motion, it is determined that the wheel end slip ratio of the wheel reaches a preset slip ratio, and the second limit adhesion force of each wheel in the vehicle is obtained based on the output torque of the prime mover. The second limit longitudinal moment corresponding to the wheel is determined based on the second limit adhesion force of the wheel and the wheel rotation angle of the wheel. Based on the second limit longitudinal torque corresponding to each wheel, the limiting torque corresponding to each wheel is adjusted, so as to limit the output torque of the prime mover based on the adjusted limiting torque corresponding to each wheel.

[0127] In one embodiment, the torque limiting module 440 is specifically used for: The adhesion coefficient of each wheel is determined based on the second limit adhesion force of the wheel. The third limiting adhesion force of each wheel is determined based on the adhesion coefficient of each wheel and the current vertical load of each wheel. The second limiting longitudinal torque corresponding to each wheel is determined based on the third limiting adhesion force of each wheel and the wheel rotation angle of each wheel.

[0128] In one embodiment, the torque limiting module 440 is further configured to: Based on the current travel change of the suspension corresponding to the wheel and the suspension tilt angle of the suspension corresponding to the wheel, determine the current vertical load change corresponding to the wheel; The current vertical load of the wheel is determined based on the static vertical load of the wheel when the vehicle is stationary, and the change in the current vertical load of the wheel.

[0129] In one embodiment, the torque limiting module 440 is specifically used for: The second limit longitudinal adhesion force of the wheel is determined based on the third limit adhesion force of the wheel and the wheel rotation angle. The second limiting longitudinal torque of the wheel is determined based on the second limiting longitudinal adhesion force of the wheel and the wheel radius.

[0130] In one embodiment, the torque limiting module 440 is specifically used for: Adjust the limiting torque corresponding to each wheel according to the second limit longitudinal torque corresponding to each wheel and the yaw moment constraint determined based on the second limit yaw moment corresponding to each wheel; The second limiting yaw moment corresponding to the wheel is determined based on the second limiting lateral adhesion force of the wheel and the longitudinal distance from the wheel axle to the vehicle's center of gravity; the second limiting lateral adhesion force of the wheel is determined based on the third limiting adhesion force of the wheel and the wheel rotation angle.

[0131] Figure 6 A second structural schematic diagram of a torque limiting device provided in this application is shown. It should be understood that this device is related to... Figure 4The method implementation described above corresponds to the method embodiment and can perform the steps involved in the aforementioned method. The specific functions of this device can be found in the description above; to avoid repetition, detailed descriptions are omitted here. This device includes at least one software function module that can be stored in a memory or embedded in the device's operating system (OS) in the form of software or firmware. Specifically, this device is applied to a vehicle, specifically to a controller mounted on the vehicle, such as a vehicle controller, for limiting the output torque of the vehicle's prime mover. The device includes: an adhesion acquisition module 510, used to determine that the wheel end slip ratio of the wheels reaches a preset slip ratio when the vehicle is in motion, and to obtain the second limit adhesion force of each wheel in the vehicle based on the output torque of the vehicle's prime mover; a longitudinal torque determination module 520, used to determine the second limit longitudinal torque corresponding to each wheel based on the second limit adhesion force and the wheel rotation angle; a limiting torque acquisition module 530, used to determine the limiting torque corresponding to each wheel based on the second limit longitudinal torque corresponding to each wheel; and an output torque limiting module 540, used to limit the output torque of the prime mover based on the limiting torque corresponding to each wheel.

[0132] Figure 7 An example is a schematic diagram of the physical structure of an electronic device, such as... Figure 7 As shown, the electronic device can specifically be a vehicle controller, which may include: a processor 610, a communication interface 620, a memory 630, and a communication bus 640. The processor 610, communication interface 620, and memory 630 communicate with each other via the communication bus 640. The processor 610 can call the computer program in the memory 630 to execute torque limiting methods, such as: When the vehicle is stationary, the speed of the prime mover of the vehicle is determined to reach a preset speed, and the first limit adhesion force of each wheel in the vehicle is obtained based on the output torque of the prime mover. The first limiting longitudinal torque of the wheel is determined based on the first limiting adhesion force of the wheel and the wheel rotation angle. Based on the first limiting longitudinal moment corresponding to each wheel, determine the limiting torque corresponding to each wheel; The output torque of the prime mover is limited according to the limiting torque corresponding to each wheel; The preset rotational speed is the critical value at which the stationary vehicle will slip on the current road surface when the rotation angle of each wheel is zero.

[0133] And / or, When the vehicle is in motion, the wheel end slip ratio is determined to reach a preset slip ratio, and the second limit adhesion force of each wheel in the vehicle is obtained based on the output torque of the prime mover of the vehicle. The second limit longitudinal moment corresponding to the wheel is determined based on the second limit adhesion force of the wheel and the wheel rotation angle of the wheel. The limiting torque corresponding to each wheel is determined based on the second limit longitudinal torque corresponding to each wheel; The output torque of the prime mover is limited according to the limiting torque corresponding to each wheel.

[0134] Furthermore, the logical instructions in the aforementioned memory 630 can be implemented as software functional units and, when sold or used as independent products, can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0135] On the other hand, embodiments of this application also provide a storage medium, which includes a computer program. The computer program can be stored on a non-transitory computer-readable storage medium. When the computer program is executed by a processor, the computer can execute the torque limiting method provided in the above embodiments.

[0136] This application also provides a vehicle that includes the electronic equipment provided in the above embodiments.

[0137] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.

[0138] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.

[0139] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. A torque limiting method, characterized in that, include: When the vehicle is stationary, the speed of the prime mover of the vehicle is determined to reach a preset speed, and the first limit adhesion force of each wheel in the vehicle is obtained based on the output torque of the prime mover. Based on the first ultimate adhesion force of the wheel and the wheel rotation angle, determine the first ultimate longitudinal torque corresponding to the wheel; The limiting torque corresponding to each wheel is determined based on the first limiting longitudinal torque corresponding to each wheel and the yaw moment constraint determined based on the first limiting yaw moment corresponding to each wheel. The output torque of the prime mover is limited according to the limiting torque corresponding to each wheel; The preset rotational speed is the critical value at which the stationary vehicle slips on the current road surface when the rotation angle of each wheel is zero. The first limiting yaw moment corresponding to the wheel is determined based on the first limiting lateral adhesion force of the wheel and the longitudinal distance from the wheel axle to the vehicle's center of gravity; the first limiting lateral adhesion force of the wheel is determined based on the first limiting adhesion force of the wheel and the wheel rotation angle.

2. The torque limiting method according to claim 1, characterized in that, The step of determining the first limiting longitudinal moment corresponding to the wheel based on the first limiting adhesion force of the wheel and the wheel rotation angle includes: The first limit longitudinal adhesion force of the wheel is determined based on the first limit adhesion force of the wheel and the wheel rotation angle of the wheel; The first limiting longitudinal torque of the wheel is determined based on the first limiting longitudinal adhesion force of the wheel and the wheel radius.

3. The torque limiting method according to claim 1, characterized in that, The step of determining the limiting torque corresponding to each wheel based on the first limiting longitudinal moment corresponding to each wheel and the yaw moment constraint determined based on the first limiting yaw moment corresponding to each wheel includes: The initial limiting torque corresponding to the wheel is determined based on the first limiting longitudinal torque corresponding to the wheel. Based on the yaw moment constraint determined by the first limit yaw moment corresponding to each wheel, the initial limiting torque corresponding to each wheel is adjusted to obtain the limiting torque corresponding to each wheel.

4. The torque limiting method according to any one of claims 1-3, characterized in that, The method further includes: When the vehicle is in motion, it is determined that the wheel end slip ratio of the wheel reaches a preset slip ratio, and the second limit adhesion force of each wheel in the vehicle is obtained based on the output torque of the prime mover. The second limit longitudinal moment corresponding to the wheel is determined based on the second limit adhesion force of the wheel and the wheel rotation angle of the wheel. Based on the second limit longitudinal torque corresponding to each wheel, the limiting torque corresponding to each wheel is adjusted, so as to limit the output torque of the prime mover based on the adjusted limiting torque corresponding to each wheel.

5. The torque limiting method according to claim 4, characterized in that, The step of determining the second ultimate longitudinal moment corresponding to the wheel based on the second ultimate adhesion force of the wheel and the wheel rotation angle includes: The adhesion coefficient of each wheel is determined based on the second limit adhesion force of the wheel. The third limiting adhesion force of each wheel is determined based on the adhesion coefficient of each wheel and the current vertical load of each wheel. The second limiting longitudinal torque corresponding to each wheel is determined based on the third limiting adhesion force of each wheel and the wheel rotation angle of each wheel.

6. The torque limiting method according to claim 5, characterized in that, The method further includes: Based on the current travel change of the suspension corresponding to the wheel and the suspension tilt angle of the suspension corresponding to the wheel, determine the current vertical load change corresponding to the wheel; The current vertical load of the wheel is determined based on the static vertical load of the wheel when the vehicle is stationary, and the change in the current vertical load of the wheel.

7. A torque limiting method, characterized in that, include: When the vehicle is in motion, the wheel end slip ratio is determined to reach a preset slip ratio, and the second limit adhesion force of each wheel in the vehicle is obtained based on the output torque of the prime mover of the vehicle. The second limit longitudinal moment corresponding to the wheel is determined based on the second limit adhesion force of the wheel and the wheel rotation angle of the wheel. Based on the second limit longitudinal moment corresponding to each wheel and the yaw moment constraint determined based on the second limit yaw moment corresponding to each wheel, the limiting torque corresponding to each wheel is determined. The output torque of the prime mover is limited according to the limiting torque corresponding to each wheel; The second limiting yaw moment corresponding to the wheel is determined based on the second limiting lateral adhesion force of the wheel and the longitudinal distance from the wheel axle to the vehicle's center of gravity; the second limiting lateral adhesion force of the wheel is determined based on the second limiting adhesion force of the wheel and the wheel rotation angle.

8. A torque limiting device, characterized in that, include: The adhesion determination module is used to determine the speed of the prime mover of the vehicle when the vehicle is stationary, and to obtain the first limit adhesion force of each wheel in the vehicle based on the output torque of the prime mover. The torque determination module is used to determine the first limit longitudinal torque corresponding to the wheel based on the first limit adhesion force of the wheel and the wheel rotation angle of the wheel. The torque determination module is used to determine the limiting torque corresponding to each wheel based on the first limiting longitudinal torque corresponding to each wheel and the yaw moment constraint determined based on the first limiting yaw moment corresponding to each wheel. A torque limiting module is used to limit the output torque of the prime mover according to the limiting torque corresponding to each wheel; The preset rotational speed is the critical value at which the stationary vehicle slips on the current road surface when the rotation angle of each wheel is zero. The first limiting yaw moment corresponding to the wheel is determined based on the first limiting lateral adhesion force of the wheel and the longitudinal distance from the wheel axle to the vehicle's center of gravity; the first limiting lateral adhesion force of the wheel is determined based on the first limiting adhesion force of the wheel and the wheel rotation angle.

9. A torque limiting device, characterized in that, include: The adhesion acquisition module is used to determine when the wheel end slip ratio of the wheel reaches a preset slip ratio when the vehicle is in motion, and to obtain the second limit adhesion force of each wheel in the vehicle based on the output torque of the prime mover of the vehicle. The longitudinal torque determination module is used to determine the second limit longitudinal torque corresponding to the wheel based on the second limit adhesion force of the wheel and the wheel rotation angle of the wheel. The limiting torque acquisition module is used to determine the limiting torque corresponding to each wheel based on the second limiting longitudinal torque corresponding to each wheel and the yaw moment constraint determined based on the second limiting yaw moment corresponding to each wheel. An output torque limiting module is used to limit the output torque of the prime mover according to the limiting torque corresponding to each wheel; The second limiting yaw moment corresponding to the wheel is determined based on the second limiting lateral adhesion force of the wheel and the longitudinal distance from the wheel axle to the vehicle's center of gravity; the second limiting lateral adhesion force of the wheel is determined based on the second limiting adhesion force of the wheel and the wheel rotation angle.

10. An electronic device, characterized in that, It includes a processor and a memory storing a computer program, wherein the processor, when executing the computer program, implements the torque limiting method according to any one of claims 1-7.

11. A vehicle, characterized in that, Including the electronic device as described in claim 10.

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