Distributed driving vehicle torque distribution method and device

Abstract

The invention discloses a distributed driving vehicle torque distribution method and device, and the method comprises the steps: calculating a first torque threshold value according to a tire vertical load, a road adhesion coefficient and a preset tire load rate threshold value; according to the road adhesion coefficient, a preset tire load rate threshold value, the vehicle mass, the gravitational acceleration and the wheel radius, a second torque threshold value is calculated; according to the request torque and the first torque threshold value, determining a distribution strategy adopting a two-wheel drive torque or a four-wheel drive torque; if the distribution strategy of the four-wheel-drive torque is adopted, the distribution mode is determined according to the request torque and the second torque threshold value. According to the method, the torque distribution strategy can be flexibly adjusted according to the working conditions of the vehicle, the situation that the full-time four-wheel-drive vehicle always distributes the torque to the front and rear four wheels at the same time under all the working conditions is avoided, energy consumption is effectively reduced, and the energy utilization rate is increased.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of automobiles, in particular to a torque distribution method and device for a distributed drive vehicle. BACKGROUND

[0002] In the operation process of a four-wheel drive vehicle, torque distribution is crucial, and greatly affects the core performance indicators of the vehicle, such as power output efficiency, handling stability, off-road passability, and fuel economy. Reasonable torque distribution can ensure that each wheel of the vehicle can obtain appropriate driving force under different road conditions, fully exert the adhesion between the tire and the ground, and avoid the occurrence of wheel slip or idling. For example, when climbing steep slopes off-road, more torque needs to be distributed to the rear wheels to increase the grip of the rear wheels and provide sufficient climbing power; when driving on wet roads, an accurate torque distribution system can quickly sense the tendency of wheel slip and timely adjust the torque to the wheel with better adhesion, ensuring the safety and stability of vehicle driving. In the current era of rapid development of new energy vehicles, electric four-wheel drive systems have great development potential due to their unique technical advantages. Compared with traditional fuel four-wheel drive systems, electric four-wheel drive systems are more compact in structure, and can partially or even completely eliminate complex power transmission and distribution parts such as transfer cases, drive shafts, and differentials. At the same time, the electric four-wheel drive system allows multiple power sources, and through accurate control of each motor, more flexible and efficient torque distribution is achieved, providing more precise control performance and powerful off-road capability for the vehicle.

[0003] In the prior art, the all-time four-wheel drive vehicle always distributes power to the front and rear four wheels in any driving state, the mechanical resistance of the transmission system is large, and the working condition efficiency of the motor is low, resulting in increased energy consumption of the vehicle and low energy utilization rate. SUMMARY

[0004] The present application provides a torque distribution method and device for a distributed drive vehicle, which can solve the technical problem of low energy utilization rate in the torque distribution technology of all-time four-wheel drive vehicles.

[0005] To achieve the above-mentioned purpose, in a first aspect, the present application provides a torque distribution method for a distributed drive vehicle, the method comprising: According to the tire vertical load, the road adhesion coefficient, and the preset tire load rate threshold, a first torque threshold is calculated.

[0006] According to the road adhesion coefficient, the preset tire load rate threshold, the vehicle mass, the gravitational acceleration, and the wheel radius, a second torque threshold is calculated.

[0007] According to the requested torque and the first torque threshold, a two-wheel drive torque or four-wheel drive torque distribution strategy is determined.

[0008] If a four-wheel drive torque distribution strategy is adopted, the distribution method is determined based on the requested torque and the second torque threshold.

[0009] Furthermore, in one embodiment, the tire vertical load is calculated based on the vehicle mass, gravitational acceleration, distance from the center of gravity to the rear axle, center of gravity height, vehicle longitudinal acceleration, vehicle lateral acceleration, front and rear track width, and front and rear wheelbase.

[0010] Furthermore, in one embodiment, determining the allocation strategy for using either second-wheel drive or fourth-wheel drive torque based on the requested torque and a first torque threshold includes: If the requested torque is less than or equal to the first torque threshold, the preset second-drive torque allocation strategy is used for torque allocation.

[0011] If the requested torque is greater than the first torque threshold, the preset four-wheel drive torque distribution strategy is used for torque distribution.

[0012] Furthermore, in one embodiment, the torque distribution using a preset two-wheel drive torque distribution strategy includes: distributing the requested torque evenly to the two rear wheels of the vehicle.

[0013] Furthermore, in one embodiment, if a four-wheel drive torque distribution strategy is adopted, the distribution method is determined based on the requested torque and the second torque threshold, including: If the requested torque is less than or equal to the second torque threshold, design the first objective function based on the tire load rate and its first weighting coefficient, and the energy consumption power and its second weighting coefficient.

[0014] Based on the preset tire load rate constraint, tire longitudinal force constraint, and torque constraint, the first objective function is solved to obtain the torque of each of the four wheels.

[0015] Furthermore, in one embodiment, the tire load rate constraint is: the tire load rate is less than a preset tire load rate threshold.

[0016] The longitudinal force constraint of the tire is: the longitudinal force of the tire is within the range of the maximum adhesion force on the ground.

[0017] The torque constraint is: the torque is within the maximum output torque range of the hub motor.

[0018] Furthermore, in one embodiment, if a four-wheel drive torque distribution strategy is adopted, the distribution method is determined based on the requested torque and the second torque threshold, including: If the requested torque is greater than the second torque threshold, a second objective function is designed based on the tire load rate and its third weighting coefficient, and the energy consumption power and its second weighting coefficient, wherein the third weighting coefficient is less than the first weighting coefficient.

[0019] Based on the preset longitudinal force constraint and torque constraint conditions of the tires, the second objective function is solved to obtain the torque of each of the four tires.

[0020] Furthermore, in one embodiment, the tire load rate is calculated based on the road surface adhesion coefficient, tire longitudinal force, and tire vertical load.

[0021] The energy consumption power is calculated based on the vehicle's motor speed, torque, and corresponding motor efficiency.

[0022] Furthermore, in one embodiment, the longitudinal force of the tire is calculated based on the requested torque and the wheel radius.

[0023] Secondly, this application provides a distributed drive vehicle torque distribution device, the device comprising: The first calculation module is used to calculate the first torque threshold based on the tire vertical load, the road surface adhesion coefficient, and the preset tire load rate threshold.

[0024] The second calculation module is used to calculate the second torque threshold based on the road surface adhesion coefficient, the preset tire load rate threshold, the vehicle mass, the gravitational acceleration, and the wheel radius.

[0025] The allocation strategy determination module is used to determine whether to use a two-wheel drive torque or a four-wheel drive torque allocation strategy based on the requested torque and the first torque threshold.

[0026] The allocation method determination module is used to determine the allocation method based on the requested torque and the second torque threshold if a four-wheel drive torque allocation strategy is adopted.

[0027] The beneficial effects of the technical solutions provided in this application include: This application calculates a first torque threshold based on tire vertical load, road surface adhesion coefficient, and a preset tire load rate threshold; it calculates a second torque threshold based on the road surface adhesion coefficient, the preset tire load rate threshold, vehicle mass, gravitational acceleration, and wheel radius; it determines whether to adopt a two-wheel drive torque distribution strategy or a four-wheel drive torque distribution strategy based on the requested torque and the first torque threshold; and it determines the distribution method of the four-wheel drive torque distribution strategy based on the requested torque and the second torque threshold. This method can flexibly adjust the torque distribution strategy according to vehicle operating conditions, avoiding the situation where all-wheel drive vehicles always distribute torque to all four wheels simultaneously under all operating conditions, thereby effectively reducing energy consumption and improving energy utilization. Attached Figure Description

[0028] Figure 1 This is a flowchart of a distributed drive vehicle torque distribution method according to an embodiment of this application.

[0029] Figure 2This is a block diagram of a distributed drive vehicle torque distribution device according to an embodiment of this application. Detailed Implementation

[0030] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present application.

[0031] To make the objectives, technical solutions, and advantages of this application clearer, the embodiments of this application will be described in further detail below with reference to the accompanying drawings.

[0032] In a first aspect, embodiments of this application provide a distributed drive vehicle torque distribution method.

[0033] In one embodiment, see Figure 1 As shown, the above-mentioned distributed drive vehicle torque distribution method includes: S1. Calculate the first torque threshold based on the tire vertical load, road surface adhesion coefficient, and preset tire load rate threshold.

[0034] S2. Calculate the second torque threshold based on the road surface adhesion coefficient, the preset tire load rate threshold, the vehicle mass, the gravitational acceleration, and the wheel radius.

[0035] S3. Determine whether to use a two-wheel drive torque or a four-wheel drive torque distribution strategy based on the requested torque and the first torque threshold. If a two-wheel drive torque distribution strategy is used, proceed to step S4. If a four-wheel drive torque distribution strategy is used, proceed to step S5.

[0036] S4. Distribute the requested torque evenly to the two rear wheels of the vehicle.

[0037] S5. Determine the allocation method based on the requested torque and the second torque threshold.

[0038] In this embodiment, a first torque threshold and a second torque threshold are dynamically calculated based on the vehicle's actual driving conditions (such as tire vertical load and road surface adhesion coefficient). The distribution strategy for either two-wheel drive or four-wheel drive torque is flexibly selected based on the relationship between the requested torque and the first and second torque thresholds. This torque distribution method fully considers the vehicle's energy efficiency. When the requested torque is small and the vehicle's driving conditions are relatively stable, two-wheel drive mode is used to reduce energy consumption. When the requested torque is large and four-wheel drive mode is needed to provide stronger grip, energy consumption is minimized while ensuring stability. This avoids the situation where a full-time four-wheel drive vehicle always distributes torque to all four wheels simultaneously under all conditions, effectively improving the vehicle's energy utilization rate.

[0039] Furthermore, in one embodiment, in step S1 above, the first torque threshold is calculated based on the tire vertical load, the road surface adhesion coefficient, and a preset tire load rate threshold. The specific calculation method is as follows: The vertical loads of the four tires are calculated based on the vehicle mass, gravitational acceleration, distance from the center of gravity to the rear axle, center of gravity height, vehicle longitudinal acceleration, vehicle lateral acceleration, front and rear wheel track, and front and rear wheel track. Formula (1) is the formula for calculating the vertical load of the left front tire, formula (2) is the formula for calculating the vertical load of the right front tire, formula (3) is the formula for calculating the vertical load of the left rear tire, and formula (4) is the formula for calculating the vertical load of the right rear tire.

[0040] (1), (2), (3), (4), in, This indicates the vertical load on the left front tire. This indicates the vertical load on the right front tire. This indicates the vertical load on the left rear tire. This indicates the vertical load on the right rear tire. Indicates vehicle mass. Represents gravitational acceleration. This represents the distance from the center of gravity to the rear axle. This indicates the distance from the center of gravity to the front axle. Indicates the height of the center of mass. Indicates the longitudinal acceleration of the vehicle. Indicates the lateral acceleration of the vehicle. Indicates the front and rear wheel track. Indicates the wheelbase of the front and rear wheels, and .

[0041] In this embodiment, the first torque threshold is calculated based on the vertical load of the rear wheel tires, the road surface adhesion coefficient, and the preset tire load rate threshold. The calculation formula (5) is as follows. This calculation method does not consider the vehicle lateral acceleration term of the vertical load of the rear wheel tires.

[0042] (5), in, Indicates the first torque threshold. Indicates the road surface adhesion coefficient. This indicates the preset tire load rate threshold.

[0043] Furthermore, in one embodiment, in step S2 above, the second torque threshold is calculated based on the road surface adhesion coefficient, the preset tire load rate threshold, the vehicle mass, the gravitational acceleration, and the wheel radius. The calculation formula (6) is as follows: (6).

[0044] Furthermore, in one embodiment, in step S3 above, the allocation strategy of using either two-wheel drive torque or four-wheel drive torque is determined based on the requested torque and the first torque threshold. The specific allocation strategy determination steps are as follows: The requested torque is compared with a first torque threshold. If the requested torque is less than or equal to the first torque threshold, a preset two-wheel drive torque allocation strategy is used for torque allocation. If the requested torque is greater than the first torque threshold, a preset four-wheel drive torque allocation strategy is used for torque allocation.

[0045] In this embodiment, by comparing the requested torque with a first torque threshold, a two-wheel drive or four-wheel drive torque distribution strategy is intelligently selected, thus optimizing the vehicle's torque distribution. When the requested torque is small and does not exceed the first torque threshold, a two-wheel drive torque distribution strategy is adopted. This simplifies the power transmission system, reduces unnecessary energy loss, thereby improving fuel efficiency or battery range, and also reducing vehicle operating costs. Conversely, when the requested torque exceeds the first torque threshold, it indicates that the vehicle may be in more complex or demanding driving conditions, such as slippery roads, steep slopes, or situations requiring stronger traction. In this case, a four-wheel drive torque distribution strategy is adopted to provide better grip and vehicle control.

[0046] Furthermore, in one embodiment, in step S3 above, the specific allocation method of the preset two-wheel drive torque allocation strategy is: to distribute the requested torque evenly to the two rear wheels of the vehicle.

[0047] That is, if < : , , in, This indicates the torque distributed to the left front wheel. This indicates the torque distributed to the right front wheel. This indicates the torque distributed to the left rear wheel. This indicates the torque distributed to the right rear wheel. This indicates a request for torque.

[0048] In this embodiment, if the requested torque is less than or equal to the first torque threshold, the two-wheel drive torque distribution strategy distributes the requested torque evenly to the two rear wheels of the vehicle. This distribution ensures that the tire load rate of the two rear wheels of the vehicle is less than the preset tire load rate threshold, which can reduce the demand on the engine or motor, thereby reducing fuel consumption or battery power consumption and improving energy utilization.

[0049] Furthermore, in one embodiment, in step S4 above, if a four-wheel drive torque distribution strategy is adopted, the distribution method is determined based on the requested torque and the second torque threshold. The specific steps are as follows: Compare the required torque with the second torque threshold. If the required torque is less than or equal to the second torque threshold, design the first objective function based on the tire load rate and its first weighting coefficient, and the energy consumption power and its second weighting coefficient. The formula (7) of the first objective function is as follows: (7), in, This represents the tire load factor of the i-th tire. This represents the energy consumption of the i-th tire. express The weighting coefficients, express The weighting coefficients, and All settings are based on empirical values.

[0050] Based on the preset tire load rate constraint, tire longitudinal force constraint, and torque constraint, the first objective function is solved to obtain the torque of each of the four wheels.

[0051] If the requested torque is greater than the second torque threshold, a second objective function is designed based on the tire load rate and its third weighting coefficient, and the energy consumption power and its second weighting coefficient. The formula (8) for the second objective function is as follows: (8), in, This indicates the third weighting coefficient, which is less than the first weighting coefficient.

[0052] The above The calculation formula is as follows: (9).

[0053] in, The value represents a coefficient. When its value is set larger, the optimization objective function focuses more on the stability of the vehicle, while when its value is set smaller, the optimization objective function focuses more on the economy of the vehicle.

[0054] Since if the requested torque is greater than the second torque threshold, no matter how the torque is allocated, it is impossible to make all tire load rates less than the threshold, the objective function is redefined by reducing the weight coefficient of the tire load rate in the first objective function, and then the torque allocated to the four wheels is determined to improve the stability of the vehicle.

[0055] Based on the preset longitudinal force constraint and torque constraint conditions of the tires, the second objective function is solved to obtain the torque of each of the four tires.

[0056] The above tire load rate constraint is: the tire load rate is less than the preset tire load rate threshold, and the corresponding constraint formula (10) is: (10).

[0057] The above-mentioned longitudinal force constraint of the tire is: within the range of the maximum adhesion force of the tire on the ground, the corresponding constraint formula (11) is: (11), in, This represents the longitudinal force of the i-th tire. This represents the vertical load on the i-th tire.

[0058] The above torque constraint is: the torque is within the maximum output torque range of the hub motor, and the corresponding constraint formula (12) is: (12).

[0059] in, This indicates the maximum output torque of the hub motor.

[0060] The above tire load rate is calculated based on the road surface adhesion coefficient, tire longitudinal force, and tire vertical load, and the calculation formula (13) is as follows: (13).

[0061] The above energy consumption power is calculated based on the vehicle's motor speed, torque, and corresponding motor efficiency. The calculation formula (14) is as follows: (14) in, This represents the energy consumption of the i-th tire. This represents the motor speed corresponding to the i-th tire. This represents the torque allocated to the i-th tire. This represents the motor efficiency corresponding to the i-th tire.

[0062] The method for determining the above-mentioned motor efficiency is as follows: Find the four nearest efficiency points to the current motor speed and current torque in the preset efficiency graph. , , and And the efficiency values ​​corresponding to the four efficiency points. , , and ,in, and .

[0063] First n The following two interpolations are performed in the direction: (15) (16).

[0064] Then in T By interpolating in the direction as follows, the motor efficiency corresponding to the current motor speed and torque can be estimated: (16).

[0065] The above-mentioned longitudinal force of the tire is calculated based on the requested torque and the wheel radius, and the calculation formula (17) is as follows: (16).

[0066] In this embodiment, an optimized objective function is selected and designed based on the comparison between the requested torque and the second torque threshold, achieving precise control of the torque of the four wheels. It considers not only tire load rate and energy consumption, but also balances vehicle stability and economy through flexible setting of weighting coefficients. When the requested torque is low, economy is prioritized; by reducing the energy consumption weighting coefficient, energy consumption is reduced, improving fuel efficiency or battery range. When the requested torque is high, the stability weighting coefficient is increased to enhance vehicle handling stability and safety, especially in complex road conditions such as slippery or steep surfaces.

[0067] Secondly, this application provides an embodiment of a distributed drive vehicle torque distribution device. See also... Figure 2 As shown, the above-mentioned device includes a first calculation module, a second calculation module, an allocation strategy determination module, and an allocation method determination module, specifically: The first calculation module is used to calculate the first torque threshold based on the tire vertical load, the road surface adhesion coefficient, and the preset tire load rate threshold.

[0068] The second calculation module is used to calculate the second torque threshold based on the road surface adhesion coefficient, the preset tire load rate threshold, the vehicle mass, the gravitational acceleration, and the wheel radius.

[0069] The allocation strategy determination module is used to determine whether to use a two-wheel drive torque or a four-wheel drive torque allocation strategy based on the requested torque and the first torque threshold.

[0070] The allocation method determination module is used to determine the allocation method based on the requested torque and the second torque threshold if a four-wheel drive torque allocation strategy is adopted.

[0071] This application proposes a distributed drive vehicle torque distribution method and device, which optimizes torque distribution under different driving conditions, significantly improving vehicle energy utilization and handling performance. First, based on tire vertical load, road surface adhesion coefficient, and a preset tire load rate threshold, two key torque thresholds are calculated: a first torque threshold and a second torque threshold. During actual torque distribution, the system intelligently selects between a two-wheel drive torque distribution strategy and a four-wheel drive torque distribution strategy based on the comparison between the requested torque and the first torque threshold. When the requested torque is small, a two-wheel drive torque distribution strategy is used, effectively simplifying the power transmission system, reducing energy loss, and improving fuel efficiency or battery range. Conversely, when the requested torque is large, a four-wheel drive torque distribution strategy is used, providing better grip and control performance, and enhancing the vehicle's passability in complex road conditions.

[0072] Furthermore, under the four-wheel drive torque distribution strategy, this application further designs and optimizes the objective function based on the comparison between the requested torque and the second torque threshold. By solving this objective function, the torque distribution method of the four wheels is accurately determined. This process considers not only tire load rate and energy consumption, but also balances vehicle stability and economy through flexible setting of weighting coefficients. When the requested torque is small, economy is prioritized by reducing energy consumption weighting coefficients; when the requested torque is large, stability weighting coefficients are increased to enhance vehicle handling stability and safety. This flexible torque distribution method allows the vehicle to maintain good performance under various driving conditions, satisfying the vehicle's power requirements while also ensuring efficient energy utilization, providing drivers with a safer, more energy-efficient, and more effective driving experience.

[0073] Therefore, the technical solution of this application has achieved significant technical effects in improving vehicle energy utilization, enhancing vehicle handling stability, and reducing vehicle operating costs.

[0074] It should be noted that the sequence numbers of the embodiments in this application are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0075] The terms "comprising" and "having," and any variations thereof, in the specification, claims, and accompanying drawings of this application are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to such process, method, product, or apparatus. The terms "first," "second," and "third," etc., are used to distinguish different objects, etc., and do not indicate a sequence, nor do they limit "first," "second," and "third" to different types.

[0076] In the description of the embodiments of this application, terms such as "exemplary," "for example," or "for instance" are used to indicate examples, illustrations, or explanations. Any embodiment or design described as "exemplary," "for example," or "for instance" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or designs. Specifically, the use of terms such as "exemplary," "for example," or "for instance" is intended to present the relevant concepts in a concrete manner.

[0077] In the description of the embodiments of this application, unless otherwise stated, " / " means "or". For example, A / B can mean A or B. The "and / or" in the text is merely a description of the relationship between related objects, indicating that there can be three relationships. For example, A and / or B can mean: A exists alone, A and B exist simultaneously, and B exists alone. In addition, in the description of the embodiments of this application, "multiple" means two or more.

[0078] In some processes described in the embodiments of this application, multiple operations or steps are included in a specific order. However, it should be understood that these operations or steps may not be executed in the order they appear in the embodiments of this application, or they may be executed in parallel. The sequence number of the operation is only used to distinguish different operations, and the sequence number itself does not represent any execution order. In addition, these processes may include more or fewer operations, and these operations or steps may be executed sequentially or in parallel, and these operations or steps may be combined.

[0079] Through the above description of the embodiments, those skilled in the art can clearly understand that the methods of the above embodiments can be implemented by means of software plus necessary general-purpose hardware platforms. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of this application, 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 is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) as described above, and includes several instructions to cause a terminal device to execute the methods described in the various embodiments of this application.

[0080] The above are merely preferred embodiments of this application and do not limit the patent scope of this application. Any equivalent structural or procedural transformations made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.

Claims

1. A method for distributed torque distribution in a driven vehicle, characterized in that, The method includes: The first torque threshold is calculated based on the tire vertical load, road adhesion coefficient, and preset tire load rate threshold. The second torque threshold is calculated based on the road surface adhesion coefficient, the preset tire load rate threshold, the vehicle mass, the gravitational acceleration, and the wheel radius. The allocation strategy of using either secondary drive torque or quaternary drive torque is determined based on the requested torque and the first torque threshold. If a four-wheel drive torque distribution strategy is adopted, the distribution method is determined based on the requested torque and the second torque threshold.

2. The distributed drive vehicle torque distribution method as described in claim 1, characterized in that, The vertical load on the tire is calculated based on the vehicle's mass, gravitational acceleration, distance from the center of gravity to the rear axle, center of gravity height, longitudinal acceleration, lateral acceleration, front and rear track width, and front and rear axle width.

3. The distributed drive vehicle torque distribution method as described in claim 1, characterized in that, The step of determining the allocation strategy for using either second-drive or fourth-drive torque based on the requested torque and the first torque threshold includes: If the requested torque is less than or equal to the first torque threshold, the preset second-drive torque allocation strategy is used for torque allocation; If the requested torque is greater than the first torque threshold, the preset four-wheel drive torque distribution strategy is used for torque distribution.

4. The distributed drive vehicle torque distribution method as described in claim 3, characterized in that, The torque distribution using a preset two-wheel drive torque distribution strategy includes: distributing the requested torque evenly to the two rear wheels of the vehicle.

5. The distributed drive vehicle torque distribution method as described in claim 1, characterized in that, If a four-wheel drive torque distribution strategy is adopted, the distribution method is determined based on the requested torque and the second torque threshold, including: If the requested torque is less than or equal to the second torque threshold, design the first objective function based on the tire load rate and its first weighting coefficient, and the energy consumption power and its second weighting coefficient. Based on the preset tire load rate constraint, tire longitudinal force constraint, and torque constraint, the first objective function is solved to obtain the torque of each of the four wheels.

6. The distributed drive vehicle torque distribution method as described in claim 5, characterized in that, The tire load rate constraint is: the tire load rate is less than a preset tire load rate threshold. The tire longitudinal force constraint is: the tire longitudinal force is within the range of maximum adhesion force on the ground; The torque constraint is: the torque is within the maximum output torque range of the hub motor.

7. The distributed drive vehicle torque distribution method as described in claim 5, characterized in that, If a four-wheel drive torque distribution strategy is adopted, the distribution method is determined based on the requested torque and the second torque threshold, including: If the requested torque is greater than the second torque threshold, a second objective function is designed based on the tire load rate and its third weighting coefficient, and the energy consumption power and its second weighting coefficient, wherein the third weighting coefficient is less than the first weighting coefficient; Based on the preset longitudinal force constraint and torque constraint conditions of the tires, the second objective function is solved to obtain the torque of each of the four tires.

8. The distributed drive vehicle torque distribution method as described in claim 5 or claim 7, characterized in that, The tire load factor is calculated based on the road adhesion coefficient, tire longitudinal force, and tire vertical load. The energy consumption power is calculated based on the vehicle's motor speed, torque, and corresponding motor efficiency.

9. The distributed drive vehicle torque distribution method as described in claim 8, characterized in that, The longitudinal force of the tire is calculated based on the requested torque and the wheel radius.

10. A distributed drive vehicle torque distribution device, characterized in that, The device includes: The first calculation module is used to calculate the first torque threshold based on the tire vertical load, the road surface adhesion coefficient, and the preset tire load rate threshold. The second calculation module is used to calculate the second torque threshold based on the road surface adhesion coefficient, the preset tire load rate threshold, the vehicle mass, the gravitational acceleration, and the wheel radius. The allocation strategy determination module is used to determine whether to use a two-wheel drive torque or a four-wheel drive torque allocation strategy based on the requested torque and the first torque threshold. The allocation method determination module is used to determine the allocation method based on the requested torque and the second torque threshold if a four-wheel drive torque allocation strategy is adopted.

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