Vehicle control method, control system, vehicle and readable storage medium

Abstract

The invention discloses a vehicle control method and system, a vehicle and a readable storage medium, and the method comprises the steps: determining the torque reduction torque of a slipping wheel when the vehicle is in a differential steering working condition and the vehicle has the slipping wheel; and the torque of the coaxial wheels is adjusted according to the torque reduction torque. According to the method, when the vehicle is determined to be in the differential steering working condition, the differential state of the vehicle is classified, the wheel slipping problem under the differential working condition is subjected to identification scheme optimization, and different driving torque control logics are used, for example, a coaxial control strategy is adopted for slipping wheels, so that the wheel slipping problem is solved. A control strategy is formulated according to the working condition of reverse slipping of the wheels on the inner side, it is guaranteed that reverse slipping of the wheels can be recognized in time, the use scene of the differential function is expanded, the phenomena of high-speed slipping of the wheels, posture deflection of a vehicle body and the like of the vehicle are avoided, and the reliability of the differential function of the vehicle is improved.

Description

Technical Field

[0001] The present invention relates to the field of vehicle technology, and in particular to a vehicle control method, a control system, a vehicle and a readable storage medium. Background Art

[0002] When a vehicle is driving, wheels often slip. Different torque control strategies need to be formulated for different wheel slip conditions to prevent the vehicle from slipping.

[0003] In the existing related technologies, TCS (Traction Control System) and ABS (Asset Backed Securitization) are mainly used to achieve this, and the technology of single-wheel torque reduction is usually adopted. However, if this technology is still used under differential working conditions, it will cause the wheels to generate undesirable yaw torque, thereby affecting the body posture.

[0004] Therefore, it is urgent to propose an anti-skid control method under differential conditions to improve the safety and reliability of vehicle differential steering. Summary of the invention

[0005] The present invention aims to solve at least one of the technical problems existing in the prior art.

[0006] To this end, an object of the present invention is to propose a vehicle control method, which, when determining that the vehicle is in a differential steering condition, classifies the differential state of the vehicle, optimizes the identification scheme for the wheel slip problem under the differential steering condition, and uses different drive torque control logics, which not only ensures that the wheel can be identified in time when reverse slip occurs, but also expands the use scenarios of the differential function, avoids the phenomenon of high-speed wheel slip and body posture deflection, and improves the reliability of the vehicle's differential function.

[0007] To this end, a second object of the present invention is to provide a vehicle control system.

[0008] To this end, a third object of the present invention is to provide a vehicle.

[0009] To this end, a fourth object of the present invention is to provide a computer-readable storage medium.

[0010] To achieve the above-mentioned objectives, an embodiment of the first aspect of the present invention discloses a vehicle control method, comprising the following steps: when the vehicle is in a differential steering condition and a slipping wheel exists on the vehicle, determining the torque reduction torque of the slipping wheel; and adjusting the torque of the coaxial wheels according to the torque reduction torque.

[0011] According to the vehicle control method of the embodiment of the present invention, when it is determined that the vehicle is in a differential steering condition and there is a slipping wheel in the vehicle, the method determines the torque reduction torque of the slipping wheel, and adjusts the torque of the coaxial wheel according to the torque reduction torque. Thus, the wheel slip problem under the differential condition is optimized and controlled, and different driving torque control logics are used, such as using a coaxial control strategy for the slipping wheel, which expands the use scenarios of the differential function, avoids the phenomenon of high-speed wheel slipping and body posture deflection in the vehicle, and improves the reliability of the vehicle differential function and user experience.

[0012] To achieve the above-mentioned objectives, an embodiment of the second aspect of the present invention discloses a vehicle control system, comprising: a determination module, used to determine the torque reduction torque of the slipping wheel when the vehicle is in a differential steering condition and the vehicle has a slipping wheel; and a control module, used to adjust the torque of the coaxial wheels according to the torque reduction torque.

[0013] According to the vehicle control system of the embodiment of the present invention, when it is determined that the vehicle is in a differential steering condition and there is a slipping wheel on the vehicle, the system determines the torque reduction torque of the slipping wheel and adjusts the torque of the coaxial wheel according to the torque reduction torque. Thus, the wheel slip problem under the differential condition is optimized and controlled, and different driving torque control logics are used, such as using a coaxial control strategy for the slipping wheel, which expands the use scenarios of the differential function, avoids the phenomenon of high-speed wheel slipping and body posture deflection in the vehicle, and improves the reliability of the vehicle differential function and the user experience.

[0014] To achieve the above-mentioned purpose, an embodiment of the third aspect of the present invention discloses a vehicle, comprising: the vehicle control system described in the embodiment of the second aspect of the present invention; or comprising: a processor, a memory, and a vehicle control program stored in the memory and executable on the processor, wherein the vehicle control program, when processed and executed, implements the vehicle control method described in the embodiment of the first aspect of the present invention.

[0015] According to the vehicle of the embodiment of the present invention, when it is determined that the vehicle is in a differential steering condition and there is a slipping wheel in the vehicle, the torque reduction torque of the slipping wheel is determined, and the torque of the coaxial wheel is adjusted according to the torque reduction torque. Thus, the wheel slip problem under the differential condition is optimized and controlled, and different driving torque control logics are used, such as using a coaxial control strategy for the slipping wheel, which expands the use scenarios of the differential function, avoids the phenomenon of high-speed wheel slipping and body posture deflection in the vehicle, and improves the reliability of the vehicle's differential function and user experience.

[0016] To achieve the above-mentioned purpose, an embodiment of the fourth aspect of the present invention discloses a computer-readable storage medium, on which a vehicle control program is stored. When the vehicle control program is executed by a processor, the vehicle control method described in the embodiment of the first aspect of the present invention is implemented.

[0017] According to the computer-readable storage medium of the embodiment of the present invention, when the vehicle control program stored thereon is executed by the processor, when it is determined that the vehicle is in a differential steering condition and there is a slipping wheel in the vehicle, the torque reduction torque of the slipping wheel is determined, and the torque of the coaxial wheel is adjusted according to the torque reduction torque. As a result, the wheel slip problem under the differential condition is optimized and controlled, and different driving torque control logics are used, such as using a coaxial control strategy for the slipping wheel, which expands the use scenarios of the differential function, avoids the phenomenon of high-speed wheel slipping and body posture deflection in the vehicle, and improves the reliability of the vehicle differential function and user experience.

[0018] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0020] Figure 1 is a flow chart of a vehicle control method according to an embodiment of the present invention;

[0021] Figure 2 is a flow chart of a vehicle control method according to another embodiment of the present invention;

[0022] Figure 3 is a flow chart of torque regulation according to one embodiment of the present invention;

[0023] Figure 4 is a schematic diagram of wheel torque distribution under differential steering conditions according to an embodiment of the present invention;

[0024] Figure 5 is a flow chart of coaxial wheel torque control according to one embodiment of the present invention;

[0025] Figure 6 is a structural block diagram of a vehicle control system according to an embodiment of the present invention;

[0026] Figure 7 is a structural block diagram of a vehicle according to an embodiment of the present invention. DETAILED DESCRIPTION

[0027] Embodiments of the present invention are described in detail below. The embodiments described with reference to the accompanying drawings are exemplary. Embodiments of the present invention are described in detail below.

[0028] Reference below Figure 1-Figure 7 A vehicle control method, a control system, a vehicle, and a readable storage medium according to embodiments of the present invention are described.

[0029] Figure 1 FIG. 1 is a flow chart of a vehicle control method according to an embodiment of the present invention. Figure 1 As shown, the vehicle control method comprises the following steps:

[0030] Step S1: When the vehicle is in a differential steering condition and a slipping wheel exists on the vehicle, the torque reduction torque of the slipping wheel is determined.

[0031] Specifically, after the vehicle is started, it is determined whether the vehicle is currently in a differential steering condition. The differential steering condition of the vehicle can be judged by the relevant information of the vehicle, such as but not limited to whether the differential steering function flag of the vehicle is activated and the actual driving torque of the wheels, etc., and whether the vehicle is currently in a differential condition is judged according to the differential function flag of the vehicle and the actual driving torque of the wheels. For example, when the differential function flag of the vehicle is in the activation flag, the vehicle is in a differential condition; or, it is judged according to the actual driving torque of each wheel, and when the actual driving torque of each wheel meets certain conditions, it is determined that the vehicle is currently in a differential condition. Among them, the differential condition means that the left and right wheels on the same axis of the vehicle can independently control and adjust the torque, for example, the left front wheel and the right front wheel of the vehicle can independently control and adjust the torque, and / or the right front wheel and the right rear wheel of the vehicle can independently control and adjust the torque. In other words, the vehicle can be a three-motor vehicle or a four-motor vehicle.

[0032] Step S2: adjusting the torque of the coaxial wheels according to the torque reduction torque.

[0033] Specifically, when the vehicle is driving, the torque passing through the transmission system will act on the wheels and push the vehicle. Wheel torque refers to the moment generated by the wheels when they rotate. Its size is related to factors such as wheel radius, tire size, vehicle speed, engine power, etc. For example, the size of the wheel torque depends on the radius of the wheel and the friction coefficient between the wheel and the ground, and the friction coefficient depends on the condition of the road surface, such as but not limited to the dryness, wetness, and gravel of the road surface. The torque of the coaxial wheels is adjusted according to the torque reduction torque so that the torque of each wheel better adapts to the current driving condition of the vehicle, which helps to improve the dynamic performance of the vehicle under the current driving condition, thereby preventing the vehicle from slipping or suppressing wheel slippage to get rid of the slippage as soon as possible, which is beneficial to improving the reliability and safety of the vehicle, as well as the user experience.

[0034] When it is determined that the vehicle is currently in a differential working condition, it is further determined whether the vehicle meets the conditions for anti-skid control intervention. For example, it is possible to determine whether the vehicle meets the conditions for anti-skid control intervention based on whether the vehicle has a slipping wheel. The wheels may include the left front wheel, the right front wheel, the left rear wheel, and the right rear wheel of the vehicle. If any one of the left front wheel, the right front wheel, the left rear wheel, and the right rear wheel of the vehicle slips, it is determined that the vehicle meets the conditions for anti-skid control intervention, and anti-skid control may be intervened on the vehicle based on this.

[0035] When it is determined that the vehicle is currently in a differential steering condition and there is a vehicle that is slipping, it is considered that the vehicle meets the conditions for anti-skid control intervention, and anti-skid control can be performed on the vehicle. After the anti-skid control intervention, the torque reduction torque of the slipping wheel is determined, and the torque of the coaxial wheel is adjusted according to the torque reduction torque, that is, the torque of the two wheels on the same axis is adjusted at the same time. For example, the torque of the left and right wheels of the front axle and / or the rear axle is uniformly adjusted to achieve vehicle anti-skid, avoid high-speed wheel slip and body posture deflection, and improve the reliability of the vehicle's differential steering function.

[0036] Therefore, the embodiment of the present invention determines that the vehicle is in a differential steering condition and has a slipping wheel, further determines the torque reduction torque of the slipping wheel, and adjusts the torque of the coaxial wheels according to the torque reduction torque, that is, achieves synchronous adjustment of the coaxial wheels, thereby avoiding high-speed wheel slippage and improving the reliability of the vehicle's differential steering function and driving safety.

[0037] Therefore, the above vehicle control method, when determining that the vehicle is in a differential steering condition and there is a slipping wheel on the vehicle, determines the torque reduction torque of the slipping wheel, and adjusts the torque of the coaxial wheel according to the torque reduction torque. As a result, the wheel slip problem under the differential condition is optimized and controlled, and different drive torque control logics are used, such as using a coaxial control strategy for the slipping wheel, which expands the use scenarios of the differential function, avoids the phenomenon of high-speed wheel slipping and body posture deflection in the vehicle, and improves the reliability of the vehicle differential function and user experience.

[0038] In one embodiment of the present invention, when the differential steering function flag of the vehicle is in the activation flag, it is determined that the vehicle is in the differential steering working condition.

[0039] In an embodiment, the vehicle may be configured with a function option for turning on the differential function. When the driver turns on the differential function according to this function option and it is determined that the driver has a greater steering demand, the differential steering function flag is automatically activated and the activation flag is output. When it is determined that the vehicle meets certain conditions, such as but not limited to the steering wheel angle, gear position, vehicle speed, etc., it is determined that the driver has a greater steering demand (such as the steering wheel angle is greater than a certain angle, the gear position is D gear, and the vehicle speed is less than a certain speed).

[0040] Specifically, if the vehicle's differential steering function flag is in the activation flag position, it can be determined that the vehicle is currently in a differential steering condition. If the vehicle's differential steering function flag is not in the activation flag position, it can be determined that the vehicle is not currently in a differential steering condition. By judging whether the vehicle is in a differential steering condition, the vehicle's differential state can be classified to facilitate the formulation of different drive anti-skid control strategies, which can help avoid vehicle slipping and improve the safety and reliability of the vehicle.

[0041] In another embodiment of the present invention, determining whether the vehicle is in a differential operating condition includes: acquiring an actual driving torque of each wheel; and determining whether the vehicle is in a differential operating condition based on the actual driving torque of each wheel.

[0042] In an embodiment, the actual driving torque of each wheel can be obtained by a wheel torque sensor, and whether the wheel is in a differential condition can be determined based on the actual torque of each wheel obtained. By determining whether the vehicle is in a differential condition, the differential state of the vehicle can be classified to facilitate the formulation of different drive anti-skid control strategies, which can help avoid vehicle slipping and improve the safety and reliability of the vehicle.

[0043] Specifically, when the absolute value of the first difference is greater than the first preset torque threshold value, and / or the absolute value of the second difference is greater than the second preset torque threshold value, it is determined that the vehicle is in a differential steering condition; wherein the first difference is the absolute value of the difference between the actual driving torque of the left front wheel and the actual driving torque of the right front wheel, and the second difference is the absolute value of the difference between the actual driving torque of the left rear wheel and the actual driving torque of the right rear wheel.

[0044] In an embodiment, the actual torque of each wheel can be obtained through the wheel torque sensor to determine whether the vehicle is in a differential state. Specifically, the actual driving torque corresponding to the left front wheel, the right front wheel, the left rear wheel and the right rear wheel of the vehicle can be obtained through the wheel torque sensor respectively, and the actual driving torque of the left front wheel is recorded as T lf , the actual driving torque of the right front wheel is recorded as T rf , the actual driving torque of the left rear wheel is recorded as T lr The actual driving torque of the right rear wheel is recorded as T rr, the absolute value of the difference between the actual driving torque of the left front wheel and the actual driving torque of the right front wheel is recorded as the absolute value of the first difference, that is, ΔT1 = |T lf -T rf |, the absolute value of the difference between the actual driving torque of the left rear wheel and the actual driving torque of the right rear wheel is recorded as the absolute value of the second difference, that is, ΔT2 = |T lr -T rr |, when the absolute value ΔT1 of the first difference is greater than the first preset torque threshold value, and / or the absolute value ΔT2 of the second difference is greater than the second preset torque threshold value, it is determined that the vehicle is in a differential steering condition. Therefore, by obtaining the actual driving torque of each wheel and judging whether the vehicle is in a differential steering condition according to the actual driving torque of each wheel, it is possible to accurately determine whether the vehicle is currently in a differential steering condition, thereby facilitating the accurate formulation of different drive anti-skid control strategies, effectively avoiding the vehicle from skidding, and improving the safety and reliability of the vehicle.

[0045] In one embodiment of the present invention, determining whether the vehicle meets the conditions for anti-skid control intervention includes: determining whether the vehicle has a slipping wheel; if so, determining that the vehicle meets the conditions for anti-skid control intervention.

[0046] In an embodiment, when it is determined that the vehicle is currently in a differential operating condition, the slip state of each wheel can be judged independently, and whether the current vehicle requires anti-skid control intervention is judged based on the slip state of the wheel. If the wheel slips, that is, any one of the four wheels of the vehicle slips, then it is judged that the vehicle meets the conditions for anti-skid control intervention, that is, the vehicle requires anti-skid control intervention.

[0047] In one embodiment of the present invention, when it is determined that any wheel satisfies the first preset condition for N consecutive cycles, it is determined that the corresponding wheel is slipping, otherwise, it is determined that the corresponding wheel is not slipping, wherein N is an integer greater than 1.

[0048] In an embodiment, Figure 3As shown, it is determined that the current vehicle is in a differential steering condition, and it is determined whether the vehicle has a slipping wheel. When determining whether the vehicle has a slipping wheel, it can be determined whether the vehicle is in a non-active braking state first. For example, it can be determined whether the vehicle is in a non-active braking state based on the size relationship between the braking depth of the brake pedal and the preset value. When the braking depth is less than the preset value, the vehicle is considered to be in a non-active braking state, and when the braking depth is greater than or equal to the preset value, the vehicle is considered to be in an active braking state. For example, the preset value can be set to 5%. When the braking depth is less than 5%, the vehicle is considered to be in a non-active braking state, and when the braking depth is greater than or equal to 5%, the vehicle is considered to be in an active braking state. For example, if the braking depth of the brake pedal of the vehicle is detected to be 3%, at this time, the braking depth of the brake pedal is less than the preset value (such as 5%), then according to whether any wheel meets the first preset condition in N consecutive cycles, it is determined whether the corresponding wheel is slipping. Specifically, the wheel can be any one of the left front wheel, the right front wheel, the left rear wheel and the right rear wheel. The number of judgment cycles can be counted according to the counter. When any wheel satisfies the first preset condition in N consecutive cycles, it is determined that the wheel has slipped. Otherwise, it is determined that the vehicle has not slipped. Wherein, N is an integer greater than 1. For example, N is taken as an example of 5. If the counter obtains that a certain wheel satisfies the first preset condition in 5 consecutive cycles, it can be determined that the wheel has slipped. If the wheel does not satisfy the first preset condition in 5 consecutive cycles, it is determined that the wheel has not slipped. For example, the wheel satisfies the first preset condition in the first 2 consecutive cycles, does not satisfy the first preset condition in the 3rd and 4th cycles, but satisfies the first preset condition in the 5th cycle. Therefore, the wheel does not satisfy the first preset condition in 5 consecutive cycles, that is, it has not slipped. Therefore, by setting a counter, any wheel can be identified as slipping, which improves the recognition rate of vehicle slipping, and can improve the reliability and safety of the vehicle, as well as the user experience.

[0049] In one embodiment of the present invention, when the absolute value of the third difference is greater than a preset wheel speed difference threshold value, and / or the absolute value of the fourth difference is greater than a preset wheel acceleration difference threshold value, it is judged that the wheel meets the first preset condition; wherein the third difference is the absolute value of the difference between the actual wheel speed of the wheel and the current vehicle speed, and the fourth difference is the absolute value of the difference between the wheel acceleration of the wheel and the longitudinal acceleration of the vehicle.

[0050] In the embodiment, the wheels include a left front wheel, a right front wheel, a left rear wheel and a right rear wheel. Taking the left front wheel as an example, the process of determining whether the left front wheel meets the first preset condition includes: for example, recording the actual wheel speed of the left front wheel as u lf , the current vehicle speed is u, and the left front wheel acceleration is u· lf , the longitudinal acceleration of the vehicle is a x, the wheel speed difference threshold is Δu, the wheel acceleration difference threshold is Δa, and the absolute value of the third difference between the actual wheel speed of the left front wheel and the current vehicle speed is recorded as ΔT3=|u lf -u|, the absolute value of the fourth difference between the left front wheel acceleration and the vehicle longitudinal acceleration is recorded as ΔT4=|u· lf -a x |, when ΔT3 is greater than Δu, and / or ΔT4 is greater than Δa, that is, it is determined that the left front wheel meets the first preset condition. In other words, when any one of the following two conditions is met, it is determined that the left front wheel meets the first preset condition, and the two conditions include:

[0051]

[0052] The above example takes the left front wheel as an example. The judgment logic of the slip status of the remaining wheels is the same as the above process, and will not be listed here one by one.

[0053] Therefore, by setting threshold values ​​for the absolute value of the wheel speed and the vehicle speed difference, and the absolute value of the wheel acceleration and the vehicle longitudinal acceleration, it can be ensured that both forward and reverse wheel slip can be identified, thereby improving the recognition rate of forward and reverse wheel slip.

[0054] In one embodiment of the present invention, the preset wheel speed difference threshold value is positively correlated with the vehicle speed value, and the preset wheel acceleration difference threshold value is positively correlated with the vehicle speed value. That is, the preset wheel speed difference threshold value increases as the vehicle speed value increases, and the preset wheel speed difference threshold value decreases as the vehicle speed value decreases. The preset wheel acceleration difference threshold value increases as the vehicle speed value increases, and the preset wheel acceleration difference threshold value decreases as the vehicle speed value decreases.

[0055] In one embodiment of the present invention, after determining that the corresponding wheel has slipped, it also includes: if it is detected that the wheel does not meet the first preset condition in M ​​consecutive cycles, and / or the torque reduction torque of the wheel is less than the preset torque, then it is judged that the wheel has recovered stability; when all wheels have recovered stability, the torque adjustment of each wheel is stopped, wherein M is an integer greater than 2.

[0056] In an embodiment, in combination Figure 3As shown, the number of judgment cycles is counted according to the counter, and when any wheel that has slipped does not meet the first preset condition within M consecutive cycles after the slipping, and / or the torque reduction torque of the wheel is less than the preset torque (such as but not limited to 100Nm), it is judged that the wheel has recovered to a stable state, and then, when all wheels have recovered to a stable state, the anti-skid control can be exited, that is, the anti-skid control of the vehicle is stopped, wherein M is an integer greater than 2. For example, taking the value of M as 5, the preset torque as 100Nm, and the wheel as the left front wheel, after the left front wheel slips, when it is detected that the left front wheel does not meet the first preset condition for 5 consecutive cycles, and the torque reduction torque of the left wheel is less than 100Nm, it is considered that the left front wheel has recovered stability, and the anti-skid control of the left front wheel can be stopped. Thus, the right front wheel, left rear wheel and right rear wheel continue to be judged. If the right front wheel, left rear wheel and right rear wheel all meet the first preset condition for 5 consecutive cycles, and the torque reduction torque corresponding to each wheel is less than the preset torque, it is considered that all wheels have recovered stability and the anti-skid control of the vehicle can be stopped. If at least one wheel still satisfies the first preset condition, the anti-skid control of the vehicle will not be stopped. For example, if the vehicle is in a differential condition and has been driving for a period of time, and the right rear wheel still satisfies the first preset condition, that is, the right rear wheel has not recovered stability and is still in a slipping state, the anti-skid control of the right rear wheel will continue until the right rear wheel fails to meet the first preset condition in M ​​consecutive cycles, and the torque reduction torque of the right rear wheel is less than the preset torque, then it is considered that the right rear wheel has recovered stability, and the anti-skid control of the vehicle can be stopped until all vehicles have recovered stability. Therefore, in the differential condition, by performing separate anti-skid control on the wheels, it can be ensured that after the wheels slip individually, the vehicle will not generate additional yaw torque, change the body posture, and improve the reliability of the vehicle differential function and user experience.

[0057] In one embodiment of the present invention, in step S2, the torque of the coaxial wheels is adjusted according to the torque reduction torque, including: determining the front axle torque reduction torque and / or the rear axle torque reduction torque corresponding to the vehicle according to the torque reduction torque; and adjusting the torque of the coaxial wheels according to the front axle torque reduction torque and / or the rear axle torque reduction torque.

[0058] In one embodiment of the present invention, the torque reduction torque corresponding to the wheel can be calculated by the difference between the current wheel speed of the slipping wheel and the vehicle speed. The torque reduction torque refers to the torque size that the wheel end torque needs to adjust in order to control the current wheel speed.

[0059] In one embodiment of the present invention, the torque reduction torque ΔT of the left front wheel is lf The calculation method is as follows:

[0060]

[0061] Where, ΔT lfis the torque reduction of the left front wheel, error lf (t) is the difference between the current left front wheel speed and the vehicle speed, K p is the proportionality coefficient, as shown in Table 1, K p The value of can be determined according to the wheel speed difference error lf (t) size can be checked; K i is the integral coefficient, as shown in Table 2, K i The value of is based on the integral value of the wheel speed difference The size can be obtained by looking up the table; K d is the differential coefficient, as shown in Table 3, K d The value of is determined according to the differential value of wheel speed difference d[error lf (t)] / dt size can be obtained by looking up the table.

[0062] As shown in Table 1 below, K p Some examples of table lookup values ​​are listed below.

[0063] <![CDATA[error lf (t)]]> -15 -10 -5 -3 0 3 5 10 15 <![CDATA[K p ]]> -300 -200 -200 -150 100 150 200 200 300

[0064] Table 1

[0065] As shown in Table 2 below, K i Some examples of table lookup values ​​are listed below.

[0066]

[0067]

[0068] Table 2

[0069] As shown in Table 3 below, K d Some examples of table lookup values ​​are listed below.

[0070] <![CDATA[d[error lf (t)] / dt]]> -500 -300 -200 -100 0 100 200 300 500 <![CDATA[K d ]]> -0.5 -0.5 -0.5 0 0 0 0.5 0.5 0.5

[0071] Table 3

[0072] For example, get the current left front wheel speed and vehicle speed, when calculating the difference between the current left front wheel speed and vehicle speed error lf (t) is -15. By looking up Table 1, we can get its corresponding K p The value is -300. If the integral value of the difference between the current left front wheel speed and the vehicle speed is -500, then by looking up Table 2, it corresponds to K i The value of is -6, and K d The value can be calculated based on the wheel speed differential value d[error lf (t)] / d is obtained by looking up Table 3. If the wheel speed differential value d[error lf(t)] / d is -500, then the corresponding K d The value is -0.5, and the obtained values ​​are substituted into the left front wheel torque reduction torque ΔT lf In the calculation formula,

[0073]

[0074] The current left front wheel torque reduction torque ΔT can be obtained lf is 7750.

[0075] The above example takes the left front wheel as the slipping wheel. The calculation process of the torque reduction torque of the remaining wheels (i.e., the right front wheel, the left rear wheel and the right rear wheel) is the same as the above process. In order to reduce redundancy, they will not be listed here one by one.

[0076] In one embodiment of the present invention, the target torque corresponding to each wheel is determined according to the torque reduction torque corresponding to the slipping wheel, including: determining the front axle torque reduction torque and the rear axle torque reduction torque corresponding to the vehicle according to the torque reduction torque corresponding to the slipping wheel; determining the target torque corresponding to each wheel according to the front axle torque reduction torque and the rear axle torque reduction torque. Then, torque is distributed to each wheel according to the target torque corresponding to each wheel.

[0077] In the embodiment, when determining the target torque corresponding to each wheel according to the torque reduction torque corresponding to the slipping wheel, the front axle torque reduction torque and the rear axle torque reduction torque corresponding to the vehicle can be determined according to the torque reduction torque corresponding to the slipping wheel, and then the target torque corresponding to each wheel can be determined according to the front axle torque reduction torque and the rear axle torque reduction torque. It can be understood that the target torque corresponding to each wheel is determined according to the front axle torque reduction torque and the rear axle torque reduction torque, and then the torque can be distributed to each wheel according to the target torque corresponding to each wheel to achieve torque adjustment of each wheel, and the torque reduction torque of the front axle and the rear axle torque reduction torque are calculated to achieve torque synchronization control of coaxial vehicles. Specifically, since the vehicle is currently in a differential steering state, in addition to the driving torque, a differential torque in the opposite direction is also applied to the coaxial wheels. If only the slipping wheels are controlled to reduce the torque, it will cause the entire vehicle to generate an unexpected yaw moment and change the magnitude of the vehicle's longitudinal force, causing the vehicle to skid, push its head or have abnormal vehicle speed. Therefore, in the differential state, the coaxial wheels need to be adjusted synchronously after the wheels slip. Therefore, the front axle torque reduction torque and rear axle torque reduction torque corresponding to the slipping wheels are determined, and then the target torque corresponding to each wheel is determined according to the front axle torque reduction torque and the rear axle torque reduction torque. This allows the torque of the coaxial wheels to be synchronously adjusted and controlled, avoiding the entire vehicle from generating an unexpected yaw moment, and preventing the vehicle from skidding, pushing its head or having abnormal vehicle speed.

[0078] In one embodiment of the present invention, Figure 5As shown, the front axle torque reduction torque and / or rear axle torque reduction torque corresponding to the vehicle is determined according to the torque reduction torque, including: when at least one of the left front wheel and the right front wheel slips, the front axle torque reduction torque and / or the rear axle torque reduction torque is calculated according to a first calculation strategy; when neither the left front wheel nor the right front wheel slips, and at least one of the left rear wheel and the right rear wheel slips, the rear axle torque reduction torque is calculated according to a second calculation strategy.

[0079] In an embodiment, Figure 5 As shown, it is determined whether the two wheels of the front axle (i.e., the left front wheel and the right front wheel) are slipping to determine whether the front axle is slipping. If at least one of the left front wheel and the right front wheel slips, it is determined that the front axle is slipping, and the front axle torque reduction torque and / or the rear axle torque reduction torque are calculated according to the first calculation strategy. If neither the left front wheel nor the right front wheel slips, and at least one of the left rear wheel and the right rear wheel slips, it is determined that the front axle is not slipping, but the rear axle is slipping, and the rear axle torque reduction torque is calculated according to the second calculation strategy, so as to determine the front axle torque reduction torque and / or the rear axle torque reduction torque corresponding to the vehicle according to the torque reduction torque corresponding to the slipping wheel. A coaxial control strategy is adopted for the slipping wheel to ensure that under the differential steering condition, the vehicle will not generate additional yaw torque and change the body posture after the single wheel slips and reduces torque.

[0080] In one embodiment of the present invention, the first calculation strategy includes:

[0081]

[0082] Where, ΔT F is the front axle torque reduction, ΔT R is the rear axle torque reduction, ΔT lf is the torque reduction torque corresponding to the left front wheel, ΔT lr is the torque reduction torque corresponding to the left rear wheel, ΔT rf is the torque reduction torque corresponding to the right front wheel, ΔT rr This is the torque reduction corresponding to the right rear wheel.

[0083] In the embodiment, when the front axle wheel slips during the vehicle's travel, the rear axle wheel has a high probability of slipping when passing through the road surface. Therefore, when the front axle wheel slips, the differential torque of the rear axle is adjusted to reduce the frequency of wheel slip, that is, the first calculation strategy is used to calculate the torque reduction torque of the front and rear axles. Specifically, the front axle torque reduction torque can be recorded as ΔT F , the rear axle torque reduction is recorded as ΔT R , the torque reduction torque corresponding to the left front wheel is recorded as ΔT lf , the torque reduction torque corresponding to the left rear wheel is recorded as ΔT lr , the torque reduction torque of the right front wheel is recorded as ΔT rf , the torque reduction torque corresponding to the right rear wheel is recorded as ΔTrr In the first calculation strategy, the front axle torque reduction torque ΔT F Take the torque reduction torque ΔT corresponding to the left front wheel lf The torque reduction ΔT corresponding to the right front wheel rf The maximum value in ΔT F =max(ΔT lf ,ΔT rf ), rear axle torque reduction ΔT R Take the torque reduction torque ΔT corresponding to the left front wheel lf , the torque reduction torque ΔT corresponding to the right front wheel rf , the torque reduction torque ΔT corresponding to the left rear wheel lr The torque reduction ΔT corresponding to the right rear wheel rr The maximum value in ΔT R =max(ΔT lf ,ΔT rf , ΔT lr ,ΔT rr ), thus, the torque reduction torque ΔT corresponding to the left front wheel is lf , the torque reduction torque ΔT corresponding to the right front wheel rf , the torque reduction torque ΔT corresponding to the left rear wheel lr The torque reduction ΔT corresponding to the right rear wheel rr , the front axle torque reduction torque ΔT can be calculated F and the rear axle torque reduction torque ΔT R .

[0084] In one embodiment of the present invention, the second calculation strategy includes:

[0085]

[0086] Where, ΔT F is the front axle torque reduction, ΔT R is the rear axle torque reduction, ΔT lr is the torque reduction torque corresponding to the left rear wheel, ΔT rr This is the torque reduction corresponding to the right rear wheel.

[0087] In an embodiment, the front axle torque reduction torque may be recorded as ΔT F , the rear axle torque reduction is recorded as ΔT R , the torque reduction torque corresponding to the left rear wheel is recorded as ΔT lr , the torque reduction torque corresponding to the right rear wheel is recorded as ΔT rr In the second calculation strategy, the front axle torque reduction torque ΔT F Take 0, that is, ΔT F =0, rear axle torque reduction ΔT R Take the torque reduction torque ΔT corresponding to the left rear wheel lr The torque reduction ΔT corresponding to the right rear wheelrr The maximum value in ΔT R =max(ΔT lr ,ΔT rr ), thus, according to the torque reduction torque ΔT corresponding to the left rear wheel lr The torque reduction ΔT corresponding to the right rear wheel rr , the rear axle torque reduction torque ΔT can be calculated R .

[0088] In one embodiment of the present invention, Figure 4 As shown, torque adjustment is performed on coaxial wheels according to the front axle torque reduction torque and / or the rear axle torque reduction torque, including: determining the target torque corresponding to each wheel according to the front axle torque reduction torque and / or the rear axle torque reduction torque; when the driving torque directions of the inner wheel and the outer wheel of the vehicle are opposite, using the third calculation strategy to calculate the target torque corresponding to each wheel; when the driving torque directions of the inner wheel and the outer wheel of the vehicle are the same, using the fourth calculation strategy to calculate the target torque corresponding to each wheel.

[0089] In an embodiment, Figure 4 As shown, it is determined that the current vehicle is in a differential steering condition. Under the differential steering condition, the inner wheel of the vehicle may exert a driving force in the opposite direction of the driving direction. Therefore, different torque adjustment schemes are formulated for the positive and reverse slip of the inner wheel. That is, when the driving torque directions of the inner wheel and the outer wheel of the vehicle are opposite, the third calculation strategy is used to calculate the target torque corresponding to each wheel, and then the torque is allocated to each wheel accordingly; when the driving torque directions of the inner wheel and the outer wheel of the vehicle are the same, the fourth calculation strategy is used to calculate the target torque corresponding to each wheel, and then the torque is allocated to each wheel accordingly. Formulating a separate control strategy for the reverse slip of the inner wheel can improve the reliability of the vehicle's differential function and the safety of the vehicle.

[0090] In one embodiment of the present invention, the third calculation strategy includes:

[0091]

[0092] Among them, T lft is the target torque of the left front wheel, T lfi The wheel end torque corresponding to the left front wheel before torque regulation (i.e. anti-skid control intervention), d is the direction of vehicle rotation, ΔT F is the front axle torque reduction, T rft is the target torque of the right front wheel, T rfi The wheel end torque corresponding to the right front wheel before torque regulation (i.e. anti-skid control intervention) is T lrt is the target torque of the left rear wheel, T lriFor torque regulation (i.e. anti-slip control intervention), the corresponding wheel end torque of the front left and rear wheels, ΔT R is the rear axle torque reduction torque, T rrt is the target torque of the right rear wheel, T rri To perform torque regulation (i.e. anti-skid control intervention), the corresponding wheel end torque of the front, right and rear wheels.

[0093] In the embodiment, the target torque of the left front wheel is denoted as T lft , the wheel end torque of the left front wheel before torque adjustment is recorded as T lfi , the vehicle rotation direction is recorded as d, and the front axle torque reduction torque is recorded as ΔT F , the target torque of the right front wheel is denoted as T rft , the wheel end torque of the right front wheel before torque adjustment is recorded as T rfi , the target torque of the left rear wheel is denoted as T lrt , the corresponding wheel end torque of the left rear wheel before torque adjustment is recorded as T lri , the rear axle torque reduction is recorded as ΔT R , the target torque of the right rear wheel is denoted as T rrt , the corresponding wheel end torque of the right rear wheel before torque adjustment is recorded as T rri Specifically, the wheel end torque T corresponding to the left front wheel before torque adjustment is performed. lfi , that is, the initial wheel-end torque of the left front wheel, which can be obtained by reading the corresponding signal on the vehicle. The wheel-end torque corresponding to the right front wheel, left rear wheel and right rear wheel before torque adjustment is obtained in the same way as the left front wheel. The wheel-end torque T corresponding to the left front wheel before torque adjustment lfi and the vehicle rotation direction d and the front axle torque reduction torque ΔT F The sum of the products is the target torque T of the left front wheel. lft The value of T lft =T lfi +d*ΔT F ; The wheel end torque T corresponding to the right front wheel before torque adjustment rfi and the vehicle rotation direction d and the front axle torque reduction torque ΔT F The sum of the products is the target torque T of the right front wheel. rft , that is, T rft =T rfi -d*ΔT F ; The corresponding wheel end torque T of the left and rear wheels before torque adjustment iri and the vehicle rotation direction d and the rear axle torque reduction torque ΔT R The sum of the products is the target torque T of the left rear wheel. lrt The value of T lrt =T lri +d*ΔT R ; The corresponding wheel end torque T of the right rear wheel before torque adjustmentrri and the vehicle rotation direction d and the rear axle torque reduction torque ΔT R The sum of the products is the target torque T of the right rear wheel. rrt The value of T rrt =T rri -d*ΔT R .

[0094] In one embodiment of the present invention, different vehicle rotation directions correspond to different values.

[0095] In the embodiment, different vehicle turning directions correspond to different values. For example, when the vehicle turns left, the vehicle turning direction is set to 1, that is, d=1; when the vehicle turns right, the vehicle turning direction is -1, that is, d=-1.

[0096] Based on this, when the vehicle turns left, the third calculation strategy includes:

[0097]

[0098] When the vehicle turns right, the third calculation strategy includes:

[0099]

[0100] In one embodiment of the present invention, the fourth computing strategy includes:

[0101]

[0102] Among them, T lft is the target torque of the left front wheel, T lfi The wheel end torque corresponding to the left front wheel before torque regulation (i.e. anti-slip control intervention) is ΔT F is the front axle torque reduction, T rft is the target torque of the right front wheel, T rfi The wheel end torque corresponding to the right front wheel before torque regulation (i.e. anti-skid control intervention) is T lrt is the target torque of the left rear wheel, T lri For torque regulation (i.e. anti-slip control intervention), the corresponding wheel end torque of the front left and rear wheels, ΔT R is the rear axle torque reduction, T rrt is the target torque of the right rear wheel, T rri To perform torque regulation (i.e. anti-skid control intervention), the corresponding wheel end torque of the front, right and rear wheels.

[0103] In the embodiment, the target torque of the left front wheel is denoted as T lft , the wheel end torque of the left front wheel before torque adjustment is recorded as T lfi , the front axle torque reduction is recorded as ΔT F , the target torque of the right front wheel is denoted as Trft , the wheel end torque of the right front wheel before torque adjustment is recorded as T rfi , the target torque of the left rear wheel is denoted as T lrt , the corresponding wheel end torque of the left rear wheel before torque adjustment is recorded as T lri , the rear axle torque reduction is recorded as ΔT R , the target torque of the right rear wheel is denoted as T rrt , the corresponding wheel end torque of the right rear wheel before torque adjustment is recorded as T rri In the fourth calculation strategy, the wheel end torque T corresponding to the left front wheel before torque adjustment is lfi and front axle torque reduction ΔT F The difference is compared with 0, that is, T lfi -ΔT F By comparing the size between 0 and T lfi -ΔT F The maximum value between 0 and 0 can be used to obtain the target torque T of the left front wheel. lft , that is, T lft =max(T lfi -ΔT F , 0); by comparing the torque adjustment before the right front wheel corresponding to the wheel end torque T rfi and front axle torque reduction ΔT F The difference between the value of T and 0 is rfi -ΔT F and 0, take T rfi -ΔT F The maximum value of the two and 0 can be obtained as the target torque T of the right front wheel. rft , that is, T rft =max(T rfi -ΔT F , 0); by comparing the torque adjustment of the left and rear wheels, the corresponding wheel end torque T iri and the rear axle torque reduction torque ΔT r The difference between the value of T and 0 is rfi -ΔT F The size between 0 and T rfi -ΔT F The maximum value of the left rear wheel torque T lrt , that is, T lrt =max(T lri -ΔT R , 0); by comparing the torque adjustment of the front right rear wheel corresponding to the wheel end torque T rri and the rear axle torque reduction torque ΔT R The difference between the value of T and 0 is rri -ΔT R The size between T and 0 isrri -ΔT R The maximum value of the two and 0 can be obtained as the target torque T of the right rear wheel. rrt , that is, T rrt =max(T rri -ΔT R , 0).

[0104] Therefore, through the above-mentioned third calculation strategy or fourth calculation strategy, the target torque corresponding to each wheel can be calculated, and then, the torque is distributed to the corresponding wheels according to the target torque corresponding to each wheel, so that the output torque of each wheel adapts to the current driving condition of the vehicle, reduces the frequency of vehicle slippage, and at the same time ensures that under differential conditions, the vehicle will not generate additional yaw moment after single-wheel slippage and torque reduction, thereby avoiding affecting the body posture and ensuring the riding experience of the occupants.

[0105] In one embodiment of the present invention, Figure 5 As shown, after calculating the target torque of each wheel of the vehicle, it also includes: performing torque limitation and smoothing anti-shake processing on the target torque.

[0106] In an embodiment, Figure 5 As shown, after calculating the target torque of each wheel, the target torque can also be torque limited and smoothed to prevent shaking. Specifically, the target torque can be limited by the maximum available torque limit of the vehicle's motor. Further, the target torque after torque limitation can be smoothed to prevent shaking. Specifically, smoothing and anti-shake processing can be performed by first-order filtering and a set torque change step limit. By performing torque limitation and smoothing and anti-shake processing on the target torque, the smoothness of the vehicle control process can be increased, and the vehicle shake can be reduced, thereby improving the user's riding experience.

[0107] As a specific embodiment, the following Figure 2 A flowchart describing the basic control logic of the vehicle control method according to an embodiment of the present invention.

[0108] Combination Figure 2 As shown, in the embodiment, the vehicle control method mainly performs the following steps:

[0109] Step S10: Start the vehicle.

[0110] Step S20: Determine whether the current vehicle is in a differential steering condition, if so, execute step S30; if not, execute step S60.

[0111] Specifically, whether the current vehicle is in a differential steering condition is determined according to the following judgment logic formula:

[0112]

[0113] Among them, Tlf , T rf , T lr , T rr Respectively represent the actual driving torque of the left front, right front, left rear and right rear wheels, and ΔT is the torque threshold value of the differential working condition. When any of the above two conditions is met or the differential steering function flag is activated, it is determined that the current vehicle is in the differential steering working condition.

[0114] Step S30: Determine whether the current vehicle state requires anti-skid control intervention, that is, whether torque adjustment is required. If so, execute step S40; if not, execute step S60.

[0115] Specifically, when any one of the four wheels slips, it is determined that the current vehicle needs torque adjustment. The slip state of each wheel is independently judged. Taking the left front wheel as an example, the judgment logic of the remaining wheels is the same, such as Figure 3 As shown, the judgment steps are as follows:

[0116] Step S301: Start the vehicle.

[0117] Step S302: Clear the counter, that is, set M = 0, N = 0. M is the number of cycles for determining whether all wheels have recovered stability, and N is the number of cycles for determining whether any wheel has slipped.

[0118] Step S303: Determine whether the braking depth is less than a preset value, for example, the preset value is 5%. If the braking depth is less than the preset value, execute step S305; if the braking depth is not less than the preset value, execute step S304.

[0119] Step S304: Output k slip =0, that is, the wheel does not meet the slipping condition and does not need torque adjustment, that is, no anti-skid control intervention is required.

[0120] Step S305: Determine the wheel speed and acceleration state, that is, determine whether the difference between the wheel state parameter and the vehicle state parameter exceeds the threshold value. If so, execute step S306; if not, execute step S307.

[0121] Specifically, the judgment logic is as follows:

[0122]

[0123] Among them, u lf The table shows the actual wheel speed of the left front wheel, u is the current vehicle speed, Δu is the wheel speed difference threshold, K1 is the wheel speed difference threshold correction coefficient, is the left front wheel acceleration, a xis the longitudinal acceleration of the vehicle, Δa is the wheel acceleration difference threshold, and K2 is the wheel acceleration difference threshold correction coefficient. When any one of the above two conditions is met, it can be judged that the difference between the wheel state parameter and the vehicle state parameter exceeds the threshold, and the judgment is true, that is, it is judged that the wheel meets the first preset condition.

[0124] In a specific example, as shown in the following Table 4, some examples of the wheel speed difference threshold value correction coefficient K1 are shown.

[0125] Speed ​​km / h 0 20 40 60 80 90 100 110 120 <![CDATA[K1]]> 1 1.05 1.1 1.15 1.2 1.25 1.3 1.35 1.4

[0126] Table 4

[0127] In a specific example, as shown in the following Table 5, some examples of the wheel acceleration difference threshold value correction coefficient K2 are shown.

[0128] <![CDATA[Vehicle acceleration m / s 2 > 0 1 2 3 4 5 6 7 8 <![CDATA[K2]]> 1 1 1 1.05 1.05 1.05 1.1 1.1 1.1

[0129] Table 5

[0130] Step S306: Set the counter to M=M+1, N=0. That is, N is whether the wheel meets the judgment condition of slipping in N consecutive cycles; M is whether the wheel meets the judgment condition of restoring stability in M ​​cycles.

[0131] Step S307: Set the counter to M=0.

[0132] Step S308: wheel slip status judgment. When the judgment results in N consecutive cycles are all true, that is, the number of consecutive cycles in which the wheel meets the first preset condition is greater than 1, execute step S309; ​​if N is not greater than 1, return to execute step S305 and repeat the above steps.

[0133] Step S309: Output k slip =1, that is, if any wheel satisfies the wheel slip condition within N consecutive cycles, torque adjustment is required.

[0134] Step S310: Determine whether the wheel is stable. slip =1. If yes, execute step S311; if no, execute step S313.

[0135] Step S311: The counter is set to N=N+1, which is an assignment formula. If the initial value is 0, it will be incremented by 1 after one cycle. That is, if the vehicle is not started and is in a stopped state, the number of consecutive cycles of the wheel detected by the counter is 0. After a period of time, the wheel rolls one or more circles, and the number of consecutive cycles of the wheel detected at this time changes from the original N=0 to N=0+1=1 at this time.

[0136] Step S312: Determine whether the wheel has recovered stability, that is, determine whether the determination result in M ​​consecutive cycles is true, that is, whether M is greater than 2, and determine whether the torque reduction torque of the wheel is less than the preset torque (such as 100Nm). If M is greater than 2, and the torque reduction torque of the wheel is less than the preset torque (such as 100Nm), then execute step S313, otherwise, execute step S308.

[0137] Step S313: Output k slip =0, that is, when all wheels meet the conditions for restoring stability in M ​​consecutive cycles and the torque reduction torque of each wheel is less than 100Nm, the vehicle's anti-skid control exits.

[0138] Step S314: End.

[0139] Step S40: Calculate the torque reduction torque of each wheel, perform proportional-integral-differential adjustment through the current wheel speed and the vehicle speed difference, and calculate the torque size that needs to be adjusted for the wheel end torque in order to control the wheel speed.

[0140] Step S50: Control the coaxial wheels to adjust the torque.

[0141] Specifically, since the current vehicle is in a differential state, such as Figure 4 As shown in the figure, in addition to the driving torque, the coaxial wheels also apply a differential torque in the opposite direction. If only the slipping wheels are subjected to torque reduction control, it will cause the vehicle to generate an unexpected yaw moment and change the longitudinal force of the vehicle, causing the vehicle to skid, push the front or have an abnormal speed. Therefore, in the differential state, the coaxial wheels need to be synchronously adjusted after the wheels slip. The torque synchronization adjustment strategy is as follows: Figure 5 As shown, the specific implementation steps are as follows:

[0142] Step S510: Start the vehicle.

[0143] Step S520: Determine whether the front axle of the vehicle is slipping, that is, whether the left front wheel and the right front wheel are slipping. If slipping occurs, execute step S530; if not, execute step S540.

[0144] Step S530: Shaft adjustment torque calculation rule 1, ie, the first calculation strategy.

[0145] Specifically, when the front axle wheels slip during the vehicle's travel, the rear axle wheels are also likely to slip when passing through this road surface. Therefore, when the front axle wheels slip, adjusting the differential torque of the rear axle is helpful to reduce the probability of wheel slippage. The calculation formula for the front and rear axle adjustment torque is:

[0146]

[0147] Where, ΔT F is the front axle torque reduction, ΔT R is the rear axle torque reduction, ΔT lf is the torque reduction torque corresponding to the left front wheel, ΔT lr is the torque reduction torque corresponding to the left rear wheel, ΔT rf is the torque reduction torque corresponding to the right front wheel, ΔT rr This is the torque reduction corresponding to the right rear wheel.

[0148] Step S540: Axis adjustment calculation rule 2, that is, the second calculation strategy, namely:

[0149]

[0150] Step S550: Calculate the wheel end target torque.

[0151] Specifically, if Figure 4 As shown, in the differential condition, the inner wheel may exert a driving force in the opposite direction of the driving direction, so the braking torque adjustment scheme is respectively used for the positive and reverse slip of the inner wheel. When the driving torque directions of the inner and outer wheels are opposite, the wheel end target torque is calculated as follows, that is, the third calculation strategy:

[0152]

[0153] When the directions of the driving torques at the inner and outer wheel ends are the same, the wheel end target torque is calculated as follows, i.e., the fourth calculation strategy:

[0154]

[0155] Step S560: According to the motor capability, the calculated target torque of each wheel end is limited and smoothed to prevent shaking.

[0156] Step S570: End.

[0157] In summary, according to the vehicle control method of the embodiment of the present invention, when it is determined that the vehicle is in a differential steering condition and there is a slipping wheel in the vehicle, the method determines the torque reduction torque of the slipping wheel, and adjusts the torque of the coaxial wheel according to the torque reduction torque. That is, when it is determined that the vehicle is in a differential steering condition, it is judged whether the vehicle meets the conditions for anti-skid control intervention; when the vehicle meets the conditions for anti-skid control intervention (that is, the vehicle slips), the vehicle is anti-skid controlled to determine the torque reduction torque of the slipping wheel, and the coaxial wheel is torque adjusted according to the torque reduction torque, so as to perform vehicle anti-skid control under differential steering conditions. In addition, by classifying the differential state of the vehicle, the identification scheme of the wheel slip problem under the differential condition is optimized, and different driving torque control logics are used, such as using a coaxial control strategy for the slipping wheel, and formulating a control strategy for the reverse slipping condition of the inner wheel, which not only ensures that the wheel can be identified in time when reverse slip occurs, but also expands the use scenario of the differential function, avoids the phenomenon of high-speed wheel slipping and body posture deflection in the vehicle, and improves the reliability of the vehicle differential function and user experience.

[0158] The present invention further provides a vehicle control system 100 in an embodiment.

[0159] Figure 6 FIG. 1 is a schematic diagram of a vehicle control system according to an embodiment of the present invention. Figure 6 As shown, the vehicle control system 100 includes: a determination module 110 and a control module 120 .

[0160] Specifically, the determination module 110 is used to determine the torque reduction torque of the slipping wheel when the vehicle is in a differential steering condition and the vehicle has a slipping wheel.

[0161] The control module 120 is used to adjust the torque of the coaxial wheels according to the torque reduction torque.

[0162] In one embodiment of the present invention, the determination module 110 determines whether the vehicle is in a differential steering condition, including: when the differential steering function flag of the vehicle is in an activation flag, determining that the vehicle is in a differential steering condition.

[0163] In one embodiment of the present invention, the determination module 110 is used to: determine that the vehicle is in a differential steering condition when the absolute value of the first difference is greater than the first preset torque threshold value, and / or the absolute value of the second difference is greater than the second preset torque threshold value; wherein the first difference is the absolute value of the difference between the actual driving torque of the left front wheel and the actual driving torque of the right front wheel, and the second difference is the absolute value of the difference between the actual driving torque of the left rear wheel and the actual driving torque of the right rear wheel.

[0164] In one embodiment of the present invention, the determination module 110 is used to: when it is determined that any wheel satisfies the first preset condition for N consecutive cycles, determine that the corresponding wheel has slipped; otherwise, determine that the corresponding wheel has not slipped, where N is an integer greater than 1.

[0165] In one embodiment of the present invention, the determination module 110 is used to: when the absolute value of the third difference is greater than a preset wheel speed difference threshold value, and / or the absolute value of the fourth difference is greater than a preset wheel acceleration difference threshold value, determine that the wheel meets the first preset condition; wherein the third difference is the absolute value of the difference between the actual wheel speed of the wheel and the current vehicle speed, and the fourth difference is the absolute value of the difference between the wheel acceleration of the wheel and the longitudinal acceleration of the vehicle.

[0166] In one embodiment of the present invention, the preset wheel speed difference threshold is positively correlated with the vehicle speed value, and the preset wheel acceleration difference threshold is positively correlated with the vehicle speed value.

[0167] In one embodiment of the present invention, after determining that the corresponding wheel has slipped, the determination module 110 is further used to: if it is detected that the wheel does not meet the first preset condition for M consecutive cycles, and / or the torque reduction torque of the wheel is less than the preset torque, then determine that the wheel has recovered stability; the control module 120 is also used to: when all wheels have recovered stability, stop torque adjustment for each wheel, where M is an integer greater than 2.

[0168] In one embodiment of the present invention, the control module 120 performs torque adjustment on the coaxial wheels according to the torque reduction torque, including: determining the front axle torque reduction torque and / or rear axle torque reduction torque corresponding to the vehicle according to the torque reduction torque; and performing torque adjustment on the coaxial wheels according to the front axle torque reduction torque and / or rear axle torque reduction torque.

[0169] In one embodiment of the present invention, the control module 120 determines the front axle torque reduction torque and / or rear axle torque reduction torque corresponding to the vehicle based on the torque reduction torque, including: when at least one of the left front wheel and the right front wheel slips, the front axle torque reduction torque and / or the rear axle torque reduction torque is calculated according to a first calculation strategy; when neither the left front wheel nor the right front wheel slips, and at least one of the left rear wheel and the right rear wheel slips, the rear axle torque reduction torque is calculated according to a second calculation strategy.

[0170] In one embodiment of the present invention, the first calculation strategy includes:

[0171]

[0172] Where, ΔT F is the front axle torque reduction, ΔT R is the rear axle torque reduction, ΔT lf is the torque reduction torque corresponding to the left front wheel, ΔT lris the torque reduction torque corresponding to the left rear wheel, ΔT rf is the torque reduction torque corresponding to the right front wheel, ΔT rr This is the torque reduction corresponding to the right rear wheel.

[0173] In one embodiment of the present invention, the second calculation strategy includes:

[0174]

[0175] Where, ΔT F is the front axle torque reduction, ΔT R is the rear axle torque reduction, ΔT lr is the torque reduction torque corresponding to the left rear wheel, ΔT rr This is the torque reduction corresponding to the right rear wheel.

[0176] In one embodiment of the present invention, the control module 120 performs torque regulation on the coaxial wheels according to the front axle torque reduction torque and / or the rear axle torque reduction torque, including: determining the target torque corresponding to each wheel according to the front axle torque reduction torque and / or the rear axle torque reduction torque; when the driving torque directions of the inner wheels and the outer wheels of the vehicle are opposite, using the third calculation strategy to calculate the target torque corresponding to each wheel; when the driving torque directions of the inner wheels and the outer wheels of the vehicle are the same, using the fourth calculation strategy to calculate the target torque corresponding to each wheel.

[0177] In one embodiment of the present invention, the third calculation strategy includes:

[0178]

[0179] Among them, T lft is the target torque of the left front wheel, T lfi The wheel end torque corresponding to the left front wheel before torque adjustment, d is the vehicle rotation direction, ΔT F is the front axle torque reduction, T rft is the target torque of the right front wheel, T rfi For torque regulation, the wheel end torque of the right front wheel is T lrt is the target torque of the left rear wheel, T lri For torque regulation, the corresponding wheel end torque of the left and rear wheels is ΔT R is the rear axle torque reduction torque, T rrt is the target torque of the right rear wheel, T rri To adjust the torque, the corresponding wheel end torque of the front right rear wheel.

[0180] In one embodiment of the present invention, the fourth calculation strategy includes:

[0181]

[0182] Among them, Tlft is the target torque of the left front wheel, T lfi For torque regulation, the wheel end torque corresponding to the left front wheel is ΔT F is the front axle torque reduction, T rft is the target torque of the right front wheel, T rfi For torque regulation, the wheel end torque of the right front wheel is T lrt is the target torque of the left rear wheel, T lri For torque regulation, the corresponding wheel end torque of the left and rear wheels is ΔT R is the rear axle torque reduction torque, T rrt is the target torque of the right rear wheel, T rri To adjust the torque, the corresponding wheel end torque of the front right rear wheel.

[0183] In one embodiment of the present invention, after calculating the target torque of each wheel of the vehicle, the control module 120 is also used to: perform torque limitation and smoothing and anti-shake processing on the target torque, and then adjust the torque of the corresponding wheel according to the target torque after torque limitation and smoothing and anti-shake processing.

[0184] It should be noted that when controlling the vehicle, the specific implementation method of the vehicle control system 100 is similar to the specific implementation method of the vehicle control method described in the above-mentioned first aspect embodiment of the present invention. Therefore, for a detailed exemplary description of the vehicle control system 100, please refer to the above-mentioned description of the vehicle control method. In order to reduce redundancy, it will not be repeated here.

[0185] According to the vehicle control system 100 of the embodiment of the present invention, when it is determined that the vehicle is in a differential steering condition and there is a slipping wheel in the vehicle, the system determines the torque reduction torque of the slipping wheel, and adjusts the torque of the coaxial wheel according to the torque reduction torque. That is, when it is determined that the vehicle is in a differential steering condition, it is judged whether the vehicle meets the conditions for anti-skid control intervention; when the vehicle meets the conditions for anti-skid control intervention (that is, the vehicle slips), the vehicle is anti-skid controlled to determine the torque reduction torque of the slipping wheel, and the coaxial wheel is torque adjusted according to the torque reduction torque, so as to perform vehicle anti-skid control under the differential steering condition. In addition, by classifying the differential state of the vehicle, the identification scheme of the wheel slip problem under the differential condition is optimized, and different driving torque control logics are used, such as using a coaxial control strategy for the slipping wheel, and formulating a control strategy for the reverse slipping condition of the inner wheel, which not only ensures that the wheel can be identified in time when reverse slip occurs, but also expands the use scenario of the differential function, avoids the phenomenon of high-speed wheel slipping and body posture deflection in the vehicle, and improves the reliability of the vehicle differential function and user experience.

[0186] A further embodiment of the present invention provides a vehicle 200 .

[0187] Figure 7 is a structural block diagram of a vehicle according to an embodiment of the present invention.

[0188] In some embodiments, Figure 7 As shown, the vehicle 200 of the embodiment of the present invention includes the vehicle control system 100 as described in any one of the above embodiments of the present invention.

[0189] In other embodiments, the vehicle 200 includes: a processor, a memory, and a vehicle control program stored in the memory and executable on the processor, and when the vehicle control program is executed by the processor, a vehicle control method as described in any of the above embodiments of the present invention is implemented.

[0190] It should be noted that when the vehicle is controlled, its specific implementation method is similar to the specific implementation method of the vehicle control method or control system of any one of the above-mentioned embodiments of the present invention. Therefore, for a detailed exemplary description of the drive anti-skid control process of the vehicle under differential conditions, please refer to the aforementioned relevant description part of the vehicle control method or control system. In order to reduce redundancy, it will not be repeated here.

[0191] According to the vehicle 200 of the embodiment of the present invention, when it is determined that the vehicle is in a differential steering condition and there is a slipping wheel in the vehicle, the vehicle 200 determines the torque reduction torque of the slipping wheel, and adjusts the torque of the coaxial wheel according to the torque reduction torque. That is, when it is determined that the vehicle is in a differential steering condition, it is judged whether the vehicle meets the conditions for anti-skid control intervention; when the vehicle meets the conditions for anti-skid control intervention (i.e., the vehicle slips), the vehicle is anti-skid controlled to determine the torque reduction torque of the slipping wheel, and the coaxial wheel is torque adjusted according to the torque reduction torque, so as to perform anti-skid control of the vehicle under the differential steering condition. In addition, by classifying the differential state of the vehicle, the identification scheme of the wheel slip problem under the differential condition is optimized, and different driving torque control logics are used, such as using a coaxial control strategy for the slipping wheel, and formulating a control strategy for the reverse slipping condition of the inner wheel, which not only ensures that the wheel can be identified in time when reverse slip occurs, but also expands the use scenario of the differential function, avoids the phenomenon of high-speed wheel slipping and body posture deflection in the vehicle, and improves the reliability of the vehicle differential function and the user experience.

[0192] A further embodiment of the present invention further discloses a computer-readable storage medium on which a vehicle control program is stored. When the vehicle control program is executed by a processor, the vehicle control method described in any one of the above embodiments of the present invention is implemented.

[0193] According to the computer-readable storage medium of the embodiment of the present invention, when the control program of the vehicle stored thereon is executed by the processor, when it is determined that the vehicle is in a differential steering condition and there is a slipping wheel in the vehicle, the torque reduction torque of the slipping wheel is determined, and the torque of the coaxial wheel is adjusted according to the torque reduction torque. That is, when it is determined that the vehicle is in a differential steering condition, it is judged whether the vehicle meets the conditions for anti-skid control intervention; when the vehicle meets the conditions for anti-skid control intervention (that is, the vehicle slips), the vehicle is subjected to anti-skid control to determine the torque reduction torque of the slipping wheel, and the torque of the coaxial wheel is adjusted according to the torque reduction torque, thereby performing vehicle anti-skid control under the differential steering condition. In addition, by classifying the vehicle's differential state, the identification scheme for the wheel slip problem under differential conditions is optimized, and different drive torque control logics are used. For example, a coaxial control strategy is adopted for the slipping wheels, and a control strategy is formulated for the condition of reverse slip of the inner wheels. This not only ensures timely identification when the wheel slips in the opposite direction, but also expands the usage scenarios of the differential function, avoids high-speed wheel slippage and body posture deflection, and improves the reliability of the vehicle's differential function and user experience.

[0194] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example.

[0195] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A vehicle control method, characterized in that: The following steps are involved: When the vehicle is in a differential steering condition and a slipping wheel exists on the vehicle, determining a torque reduction torque of the slipping wheel; The torque of the coaxial wheels is adjusted according to the torque reduction torque.

2. The vehicle control method according to claim 1, characterized in that: The torque of the coaxial wheels is adjusted according to the torque reduction torque, including: Determining a front axle torque reduction torque and / or a rear axle torque reduction torque corresponding to the vehicle according to the torque reduction torque; The torque of the coaxial wheels is adjusted according to the front axle torque reduction torque and / or the rear axle torque reduction torque.

3. The vehicle control method according to claim 2, characterized in that: Determining the front axle torque reduction torque and / or the rear axle torque reduction torque corresponding to the vehicle according to the torque reduction torque includes: When at least one of the left front wheel and the right front wheel slips, the front axle torque reduction torque and / or the rear axle torque reduction torque are calculated according to a first calculation strategy; When neither the left front wheel nor the right front wheel slips, and at least one of the left rear wheel and the right rear wheel slips, the rear axle torque reduction torque is calculated according to the second calculation strategy.

4. The vehicle control method according to claim 3, characterized in that: The first calculation strategy includes: Where, ΔT F is the front axle torque reduction torque, ΔT R is the rear axle torque reduction torque, ΔT lf is the torque reduction torque corresponding to the left front wheel, ΔT lr is the torque reduction torque corresponding to the left rear wheel, ΔT rf is the torque reduction torque corresponding to the right front wheel, ΔT rr This is the torque reduction corresponding to the right rear wheel.

5. The vehicle control method according to claim 3, characterized in that: The second calculation strategy includes: Where, ΔT F is the front axle torque reduction torque, ΔT R is the rear axle torque reduction torque, ΔT lr is the torque reduction torque corresponding to the left rear wheel, ΔT rr This is the torque reduction corresponding to the right rear wheel.

6. The vehicle control method according to claim 4 or 5, characterized in that: The torque of the coaxial wheels is adjusted according to the front axle torque reduction torque and / or the rear axle torque reduction torque, including: Determining a target torque corresponding to each wheel according to the front axle torque reduction and / or the rear axle torque reduction; When the driving torque directions of the inner wheel and the outer wheel of the vehicle are opposite, a third calculation strategy is used to calculate the target torque corresponding to each wheel; When the driving torque directions of the inner wheels and the outer wheels of the vehicle are the same, the fourth calculation strategy is used to calculate the target torque corresponding to each wheel.

7. The vehicle control method according to claim 6, characterized in that: The third calculation strategy includes: Among them, T lft is the target torque of the left front wheel, T lfi The wheel end torque corresponding to the left front wheel before torque adjustment, d is the vehicle rotation direction, ΔT F is the front axle torque reduction torque, T rft is the target torque of the right front wheel, T rfi For torque regulation, the wheel end torque of the right front wheel is T lrt is the target torque of the left rear wheel, T lri For torque regulation, the corresponding wheel end torque of the front left and rear wheels is ΔT R is the rear axle torque reduction torque, T rrt is the target torque of the right rear wheel, T rri To adjust the torque, the corresponding wheel end torque of the front right rear wheel is set.

8. The vehicle control method according to claim 6, characterized in that: The fourth calculation strategy includes: Among them, T lft is the target torque of the left front wheel, T lfi For torque regulation, the wheel end torque corresponding to the left front wheel is ΔT F is the front axle torque reduction torque, T rft is the target torque of the right front wheel, T rfi For torque regulation, the wheel end torque of the right front wheel is T lrt is the target torque of the left rear wheel, T lri For torque regulation, the corresponding wheel end torque of the front left and rear wheels is ΔT R is the rear axle torque reduction torque, T rrt is the target torque of the right rear wheel, T rri To adjust the torque, the corresponding wheel end torque of the front right rear wheel is set.

9. The vehicle control method according to claim 1, characterized in that: When the differential steering function flag of the vehicle is in the activation flag position, it is determined that the vehicle is in the differential steering operating condition.

10. The vehicle control method according to claim 1, characterized in that: When the absolute value of the first difference is greater than the first preset torque threshold value, and / or the absolute value of the second difference is greater than the second preset torque threshold value, determining that the vehicle is in the differential steering working condition; The first difference is the absolute value of the difference between the actual driving torque of the left front wheel and the actual driving torque of the right front wheel, and the second difference is the absolute value of the difference between the actual driving torque of the left rear wheel and the actual driving torque of the right rear wheel.

11. The vehicle control method according to claim 1, characterized in that: When it is determined that any one of the wheels satisfies the first preset condition for N consecutive cycles, it is determined that the corresponding wheel has slipped; otherwise, it is determined that the corresponding wheel has not slipped, wherein N is an integer greater than 1.

12. The vehicle control method according to claim 11, characterized in that: When the absolute value of the third difference is greater than a preset wheel speed difference threshold value, and / or the absolute value of the fourth difference is greater than a preset wheel acceleration difference threshold value, it is determined that the wheel meets the first preset condition; The third difference is the absolute value of the difference between the actual wheel speed of the wheel and the current vehicle speed, and the fourth difference is the absolute value of the difference between the wheel acceleration of the wheel and the longitudinal acceleration of the vehicle.

13. The vehicle control method according to claim 12, characterized in that: The preset wheel speed difference threshold value is positively correlated with the vehicle speed value, and the preset wheel acceleration difference threshold value is positively correlated with the vehicle speed value.

14. The vehicle control method according to claim 11, characterized in that: After determining that the corresponding wheel slips, the method further includes: If it is detected that the wheel does not meet the first preset condition in M ​​consecutive cycles, and / or the torque reduction torque of the wheel is less than the preset torque, it is determined that the wheel has recovered stability; When all the wheels recover to be stable, the torque adjustment for each wheel is stopped, wherein M is an integer greater than 2.

15. A vehicle control system, characterized in that: include: a determination module, configured to determine a torque reduction torque of a slipping wheel when the vehicle is in a differential steering condition and the vehicle has a slipping wheel; The control module is used to adjust the torque of the coaxial wheels according to the torque reduction torque.

16. A vehicle, characterized in that: include: The vehicle control system as claimed in claim 15; or, A processor, a memory, and a vehicle control program stored in the memory and executable on the processor, wherein the vehicle control program, when executed by the processor, implements the vehicle control method as described in any one of claims 1 to 14.

17. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a vehicle control program, and when the vehicle control program is executed by the processor, the vehicle control method according to any one of claims 1 to 14 is implemented.

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