Vehicle Stability Control Method, Device and New Energy Vehicle Based on Low Adhesion Conditions

Abstract

The present application provides a vehicle stability control method, device and new energy vehicle based on a low adhesion condition. The method includes: obtaining the slip ratio of the current vehicle, and determining whether the current vehicle is in a low adhesion condition based on the slip ratio; when it is monitored that the vehicle triggers the anti-reverse function, using a predetermined wheel reverse trend determination method to judge the rotation state of the vehicle's wheels to determine whether the vehicle's wheels are in a reverse state; when it is determined that the vehicle is in a low adhesion condition and at least one wheel of the vehicle is in a reverse state, resetting a predetermined torque anti-reverse attenuation coefficient, and adjusting the coasting recovery torque of the current vehicle by using the reset torque anti-reverse attenuation coefficient; transmitting the adjusted coasting recovery torque to the drive motor to perform torque control to slow down the reverse trend of the wheels. The present application can slow down the reverse trend of the wheels, ensure the driving stability of the vehicle under low adhesion conditions, and improve the driving experience and driving safety.

Description

Technical Field

[0001] The present application relates to the technical field of new energy vehicles, and particularly to a vehicle stability control method, device and new energy vehicle based on low adhesion conditions. Background Technique

[0002] Under the background of the global energy revolution, new energy vehicles are popular among consumers due to their excellent energy consumption performance. Currently, the new energy vehicles for sale usually have a coasting energy recovery function to improve energy utilization and cruising range. Vehicles with a coasting energy recovery function perform negative torque during coasting for motor regenerative braking.

[0003] However, when the vehicle is driving on low adhesion roads such as snow, ice, and epoxy floor roads with water, due to the combined influence of the motor negative torque caused by coasting energy recovery and the very low adhesion coefficient of the special road surface, the vehicle is prone to reverse rotation of the wheels, which can easily cause a series of problems such as the vehicle surging forward and even losing stability, seriously affecting the driving experience and driving safety of the vehicle under low adhesion conditions. Summary of the Invention

[0004] In view of this, the embodiments of the present application provide a vehicle stability control method, device and new energy vehicle based on low adhesion conditions to solve the problems in the prior art that the vehicle is prone to reverse rotation of the wheels due to coasting energy recovery, affecting the driving experience and driving safety of the vehicle under low adhesion conditions.

[0005] In the first aspect of the embodiments of the present application, a vehicle stability control method based on low adhesion conditions is provided, including: obtaining the slip ratio of the current vehicle, and determining whether the current vehicle is in a low adhesion condition based on the slip ratio; when it is monitored that the vehicle triggers the anti-reverse function, using a predetermined method for determining the wheel reverse trend to judge the rotation state of the vehicle's wheels to determine whether the vehicle's wheels are in a reverse state; when it is determined that the vehicle is in a low adhesion condition and at least one wheel of the vehicle is in a reverse state, resetting a predetermined torque anti-reverse attenuation coefficient, and adjusting the coasting recovery torque of the current vehicle using the reset torque anti-reverse attenuation coefficient; transmitting the adjusted coasting recovery torque to the drive motor to perform torque control to slow down the reverse trend of the wheels.

[0006] In the second aspect of the embodiments of the present application, a vehicle stability control device based on low adhesion conditions is provided, including: an acquisition module configured to acquire the slip ratio of the current vehicle and determine whether the current vehicle is in a low adhesion condition based on the slip ratio; a judgment module configured to, when it is monitored that the vehicle triggers the anti-reversal function, use a predetermined method for determining the wheel reversal trend to judge the rotational state of the vehicle's wheels to determine whether the vehicle's wheels are in a reversed state; an adjustment module configured to, when it is determined that the vehicle is in a low adhesion condition and at least one wheel of the vehicle is in a reversed state, reset a predetermined torque anti-reversal attenuation coefficient and use the reset torque anti-reversal attenuation coefficient to adjust the coasting recovery torque of the current vehicle; a control module configured to transmit the adjusted coasting recovery torque to the drive motor to perform torque control to slow down the wheel reversal trend.

[0007] In the third aspect of the embodiments of the present application, a new energy vehicle is provided, including a vehicle controller, a motor controller, a drive motor, and a transmission system; the vehicle controller is used to implement the steps of the above vehicle stability control method based on low adhesion conditions to send the adjusted coasting recovery torque to the motor controller; the motor controller is used to perform torque control on the drive motor through the transmission system according to the adjusted coasting recovery torque.

[0008] The above at least one technical solution adopted in the embodiments of the present application can achieve the following beneficial effects:

[0009] By acquiring the slip ratio of the current vehicle and determining whether the current vehicle is in a low adhesion condition based on the slip ratio; when it is monitored that the vehicle triggers the anti-reversal function, using a predetermined method for determining the wheel reversal trend to judge the rotational state of the vehicle's wheels to determine whether the vehicle's wheels are in a reversed state; when it is determined that the vehicle is in a low adhesion condition and at least one wheel of the vehicle is in a reversed state, resetting a predetermined torque anti-reversal attenuation coefficient and using the reset torque anti-reversal attenuation coefficient to adjust the coasting recovery torque of the current vehicle; transmitting the adjusted coasting recovery torque to the drive motor to perform torque control to slow down the wheel reversal trend. Therefore, when the wheels reverse, the present application can timely limit the output of the coasting recovery torque by resetting the torque anti-reversal attenuation coefficient, so as to slow down the wheel reversal trend, ensure the driving stability of the vehicle under low adhesion conditions, and improve the driving experience and driving safety. Description of the Drawings

[0010] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for use in the embodiments or the description of the prior art. Obviously, the following drawings are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0011] Figure 1 is a schematic flowchart of a vehicle stability control method based on a low-adhesion condition provided by an embodiment of the present application;

[0012] Figure 2 is a schematic structural diagram of a vehicle stability control device based on a low-adhesion condition provided by an embodiment of the present application;

[0013] Figure 3 is a schematic structural diagram of an electronic device provided by an embodiment of the present disclosure. Detailed implementation manners

[0014] In the following description, for the purpose of illustration rather than limitation, specific details such as specific system architectures and technologies are presented to thoroughly understand the embodiments of the present application. However, those skilled in the art should clearly understand that the present application can also be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to avoid unnecessary details from hindering the description of the present application.

[0015] Under the background of the global energy revolution, new energy vehicles have won the favor of the majority of consumers with their excellent energy efficiency. To improve energy utilization efficiency and driving range, existing new energy vehicles generally adopt a coasting energy recovery function, that is, during the coasting process of the vehicle, regenerative braking is achieved by applying negative motor torque, converting kinetic energy into electrical energy and storing it back into the battery.

[0016] However, there are certain problems in the existing technology. When the vehicle is driving on low-adhesion road surfaces such as snow, ice, and epoxy floor surfaces with water, due to the combined influence of the negative motor torque caused by coasting energy recovery and the low special road surface adhesion coefficient, the vehicle may experience reverse rotation of the wheels, which may cause a series of problems such as the vehicle surging forward and even losing stability, seriously affecting the driving experience and driving safety of the vehicle under low-adhesion conditions.

[0017] The existing technology has not provided an effective solution to prevent the reverse rotation of the wheels caused by coasting energy recovery, especially when driving on low-adhesion road surfaces. This problem may seriously affect the driving experience and driving safety. In addition, although in the existing technology, the parameters of the coasting energy recovery system can be modified to reduce the negative torque generated under low-adhesion conditions, this may reduce the energy recovery efficiency and affect the driving range. Moreover, this method may not be able to quickly respond after the wheels start to reverse, thus unable to effectively prevent the vehicle from surging forward or losing stability.

[0018] In view of the problems existing in the prior art, the embodiments of the present application provide a vehicle stability control method based on low adhesion conditions. When the vehicle monitoring system triggers the anti-reversal function, the slip ratio of the current vehicle is obtained, and it is determined whether the vehicle is in a low adhesion condition based on the slip ratio. At the same time, a predetermined method for determining the wheel reversal trend is used to determine whether the wheels of the vehicle are in a reversed state. If the vehicle is in a low adhesion condition and at least one wheel is in a reversed state, the predetermined torque anti-reversal attenuation coefficient is reset, and the slip recovery torque of the current vehicle is adjusted using the reset torque anti-reversal attenuation coefficient. Then, the adjusted slip recovery torque is transmitted to the drive motor for torque control to slow down the reversal trend of the wheels. In this way, when the wheels of the vehicle reverse, the present application can timely limit the output of the slip recovery torque by resetting the torque anti-reversal attenuation coefficient, thereby slowing down the reversal trend of the wheels and ensuring the driving stability of the vehicle under low adhesion conditions. The technical solution of the present application improves the driving experience and driving safety without significantly reducing the energy recovery efficiency.

[0019] It should be noted that the new energy vehicles in the embodiments of the present application refer to vehicles that use new energy (non-traditional petroleum and diesel energy) and have advanced technologies. These vehicles adopt new power systems, which can effectively reduce vehicle emissions, reduce the impact on the environment, and improve energy utilization efficiency. The new energy vehicles in the embodiments of the present application include, but are not limited to, the following types of vehicles: electric vehicles (EV), battery electric vehicles (BEV), fuel cell electric vehicles (FCEV), plug-in hybrid electric vehicles (PHEV), and hybrid electric vehicles (HEV), etc.

[0020] The technical solution of the present application will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0021] Figure 1 It is a flowchart showing the vehicle stability control method based on low adhesion conditions provided by the embodiments of the present application. Figure 1 The vehicle stability control method based on low adhesion conditions can be executed by the vehicle controller of a new energy vehicle. As Figure 1 shown, the vehicle stability control method based on low adhesion conditions can specifically include:

[0022] S101, obtain the slip ratio of the current vehicle, and determine whether the current vehicle is in a low adhesion condition based on the slip ratio;

[0023] S102, when it is monitored that the vehicle triggers the anti-reversal function, use a predetermined method for determining the wheel reversal trend to judge the rotation state of the wheels of the vehicle to determine whether the wheels of the vehicle are in a reversed state;

[0024] S103. When it is determined that the vehicle is in a low - adhesion condition and at least one wheel of the vehicle is in a reverse state, reset a predetermined torque anti - reverse attenuation coefficient, and use the reset torque anti - reverse attenuation coefficient to adjust the current vehicle's coasting energy recovery torque;

[0025] S104. Transmit the adjusted coasting energy recovery torque to the drive motor to perform torque control, so as to slow down the reverse trend of the wheels.

[0026] The coasting energy recovery function of new - energy vehicles, which is usually also known as regenerative braking or regen braking, is an energy management technology. In traditional internal - combustion engine vehicles, when the vehicle decelerates or brakes, the kinetic energy of the vehicle is converted into heat energy through the braking system and dissipated into the environment along with the friction of the brake pads. This is an energy loss.

[0027] However, new - energy vehicles can utilize the characteristics of the motor to recover this part of the energy. When the vehicle decelerates or brakes, the operating mode of the motor can be switched to become a generator. At this time, the kinetic energy of the wheels is converted into electrical energy through the motor and then stored in the battery. This is the so - called coasting energy recovery function. In specific operations, when the vehicle is coasting or braking, the motor will apply a reverse torque (that is, a negative torque), which will slow down the wheels and also cause the motor to generate current. This current is the electrical energy converted from the kinetic energy of the vehicle and can be stored back in the battery for subsequent use.

[0028] The coasting energy recovery function can improve the energy efficiency of new - energy vehicles because it reduces energy loss and extends the service life of the battery. At the same time, regenerative braking can also reduce the dependence on the traditional braking system, thereby reducing the wear of the braking system and the maintenance cost.

[0029] The low - adhesion condition (low - adhesion force condition) refers to the situation where, during the driving process of the vehicle, due to road surface environmental factors, the friction coefficient between the vehicle tires and the road surface decreases, thus affecting the driving stability and safety of the vehicle. In the low - adhesion force condition, the vehicle's grip decreases, and phenomena such as skidding and loss of control are likely to occur. The vehicle may be in a low - adhesion condition in the following situations:

[0030] Wet road surface: Rainy days, roads after rain, or wet road surfaces caused by other reasons may reduce the friction coefficient between the tires and the road surface, reducing vehicle stability.

[0031] Icy road surface: In cold winter weather, the road surface freezes, significantly reducing the friction coefficient between the tires and the road surface, resulting in the vehicle being prone to skidding and loss of control.

[0032] Sandy road surface: In desert areas, windy and sandy weather, or near road construction sites, there may be sand and dust on the road surface, which will reduce the friction coefficient between the tires and the road surface.

[0033] Snow-covered road surface: In snowy areas, the snow on the road reduces the friction coefficient between the tires and the road surface, increasing the driving risk.

[0034] Other special road surfaces: Such as epoxy floors with water, loose gravel road surfaces, etc. These special road surface conditions may also cause the vehicle adhesion to decrease, thus being in a low-adhesion working condition.

[0035] It should be understood that the various steps described in the method embodiments of the present application can be executed in different orders and / or in parallel. For example, steps S101 and S102 can be executed in parallel, that is, while obtaining the vehicle slip ratio for low-adhesion working condition judgment, the anti-reversal function of the vehicle can be monitored in real time and the reversal state of the wheels can be judged. In addition, the method embodiments may include additional steps and / or omit the steps shown. The scope of the present disclosure is not limited in this regard.

[0036] In some embodiments, obtaining the slip ratio of the current vehicle and judging whether the current vehicle is in a low-adhesion working condition based on the slip ratio includes: obtaining the vehicle's overall vehicle speed, ESC overall vehicle speed, and the wheel speeds of each wheel, and calculating the vehicle's slip ratio using the overall vehicle speed, ESC overall vehicle speed, and the wheel speeds of each wheel; when the vehicle's slip ratio is less than a preset slip ratio threshold, it is judged that the current vehicle is in a low-adhesion working condition.

[0037] Specifically, before calculating the vehicle's slip ratio, first calculate the overall vehicle speed according to the front and rear motor speeds in the vehicle motion parameters monitored by the VCU in real time, that is, by obtaining the front motor speed and rear motor speed of the vehicle and calculating the overall vehicle speed based on the front motor speed and rear motor speed. The following explains the calculation process of the overall vehicle speed in combination with the formula, which may specifically include the following content:

[0038]

[0039]

[0040]

[0041] Formula (1) is used to calculate the overall vehicle speed v m , where v m represents the overall vehicle speed, represents the vehicle speed corresponding to the front motor speed, represents the vehicle speed corresponding to the rear motor speed.

[0042] Formula (2) is used to calculate the vehicle speed corresponding to the front motor speed (i.e., the vehicle speed calculated based on the front motor speed), where n f represents the front motor speed, r f represents the front wheel radius, if Represents the front motor speed ratio;

[0043] Formula (3) is used to calculate the vehicle speed corresponding to the rear motor speed (i.e., the vehicle speed calculated based on the rear motor speed), where n r Represents the rear motor speed, r r Represents the rear wheel radius, i r Represents the rear motor speed ratio.

[0044] Furthermore, after obtaining the vehicle's overall vehicle speed v m , according to the ESC overall vehicle speed v, the wheel speeds v wheelFL , v wheelFR , v wheelRL , v wheelRR , and the overall vehicle speed v m , the following formula is used to calculate the slip ratio β of the vehicle:

[0045]

[0046] Among them, β represents the slip ratio of the vehicle, v represents the ESC overall vehicle speed, v m Represents the overall vehicle speed calculated based on the motor speed, v wheelFL Represents the wheel speed of the left front wheel, v wheelFR Represents the wheel speed of the right front wheel, v wheelRL Represents the wheel speed of the left rear wheel, v wheelRR Represents the wheel speed of the right rear wheel.

[0047] It should be noted that the ESC overall vehicle speed refers to the value corresponding to the overall vehicle speed signal sent by the ESC. ESC (Electronic Stability Control) is an electronic driving assistance system mainly used to improve the driving stability of the vehicle and prevent the vehicle from losing control in sharp turns or other extreme driving situations.

[0048] The ESC system monitors the driving state of the vehicle, including parameters such as vehicle speed, steering angle, and wheel speed. When the system detects that the vehicle may slide or lose control (for example, the actual driving direction of the vehicle does not match the driver's steering intention), the ESC system will automatically intervene. This intervention includes independently braking individual wheels and adjusting the power output of the engine to help the driver maintain control of the vehicle.

[0049] In the embodiments of the present application, the ESC system may play an important role when the vehicle is in a low adhesion working condition. In this case, due to slippery road surface or other reasons, the wheels of the vehicle may be more likely to slip, and the stability of the vehicle may be reduced. At this time, the ESC system can help maintain the stability of the vehicle and improve driving safety by independently braking the wheels and adjusting the slip recovery torque, etc.

[0050] Further, after obtaining the slip ratio of the vehicle, compare the slip ratio β of the vehicle with a preset slip ratio threshold. When the slip ratio β of the vehicle is less than the preset slip ratio threshold β th i.e., β < β th then it is determined that the current vehicle is traveling on a low adhesion road surface, that is, it is determined that the current vehicle is in a low adhesion working condition.

[0051] In some embodiments, before using a predetermined wheel reverse trend determination method to judge the rotation state of the vehicle's wheels, the method further includes: obtaining the real-time gear information and gear valid bit of the vehicle, and judging whether the gear information is valid based on the gear valid bit; when the gear information is determined to be valid, judging whether the gear information is a forward gear, and when it is judged to be a forward gear, triggering the anti-reverse function of the vehicle.

[0052] Specifically, the present application uses a VCU (Vehicle Control Unit) to monitor various motion parameters of the vehicle in real time. For example, the real-time motion parameters of the vehicle include but are not limited to the following parameters: the wheel speed and wheel speed valid bit of each wheel, the wheel speed direction and wheel speed direction valid bit, the motor speed and motor speed valid bit, the gear and gear valid bit, the vehicle torque and vehicle torque valid bit, the actual torque values of the front and rear motors, etc.

[0053] It should be noted that in computer and data processing, the "valid bit" usually refers to the bit that contains useful or important information. For digital representation, the valid bit may refer to the bit that actually represents the numerical value, rather than the bit used for other purposes (such as signs, error checking, or padding, etc.). In the field of new energy vehicles, the "valid bit" in the embodiments of the present application is used to verify whether the signals obtained by the VCU in real time are valid. For example, signals such as wheel speed, wheel speed direction, and motor speed are verified. The valid bit can be used to judge whether the signal is valid. The so-called validity means whether the obtained signal is credible. When it is judged that the signal is invalid using the valid bit, it means that the numerical value of the signal is not credible. For example, there may be a fault, resulting in inaccurate transmitted signals.

[0054] In one example, in the embodiments of the present application, the VCU monitors the vehicle motion parameters in real time, obtains the gear information and the gear valid bit of the vehicle, and uses the gear valid bit to judge the validity of the gear information, that is, to judge whether the current gear information of the vehicle is available. When it is judged that the gear information of the vehicle is valid, it is further judged whether the gear information is a forward gear. When the gear information is valid and the whole vehicle gear is a forward gear (such as the D gear), the anti-reverse function of the vehicle is enabled. In practical applications, when it is judged that the gear information of the vehicle is invalid, it is proved that the gear information is an error message, and no subsequent operations are continued at this time.

[0055] In some embodiments, after it is judged that the current vehicle is in a low-adhesion working condition, the method further includes:

[0056] Obtain the total vehicle torque, the actual front motor torque, and the actual rear motor torque of the vehicle, compare the total vehicle torque, the actual front motor torque, and the actual rear motor torque with their respective corresponding torque thresholds respectively. When any one of the total vehicle torque, the actual front motor torque, and the actual rear motor torque is less than its corresponding torque threshold, it is judged that the current vehicle is in the coasting energy recovery state.

[0057] Specifically, obtain the total vehicle torque T, the actual front motor torque T fm and the actual rear motor torque T rm monitored in real time by the VCU, compare the total vehicle torque T, the actual front motor torque T fm and the actual rear motor torque T rm with their respective corresponding torque thresholds respectively. When any one of the above three torque values meets the condition (that is, less than the corresponding torque threshold), it is judged that the current vehicle is in the coasting energy recovery state.

[0058] In one example, the torque threshold corresponding to the total vehicle torque T is represented as T th , and the torque threshold corresponding to the actual front motor torque T fm is represented as The torque threshold corresponding to the actual rear motor torque T rm is represented as Therefore, when it is judged that T < T th , or , it is judged that the vehicle is in the coasting energy recovery state.

[0059] The embodiments of the present application provide two methods for judging the reverse trend of the wheels to judge the rotation state of the wheels, so as to judge whether the wheels are in the reverse state. The following will respectively describe these two methods for judging the reverse trend of the wheels in detail in combination with specific embodiments.

[0060] In one example, a predetermined wheel reverse trend determination method is used to judge the rotation state of the wheels of a vehicle, including: obtaining the wheel speed, wheel speed direction, wheel speed valid bit, and wheel speed direction valid bit of each wheel, using the wheel speed direction valid bit to judge whether the wheel speed direction is valid. When the wheel speed direction is determined to be valid and the wheel speed direction of any one wheel is the reverse direction; using the wheel speed valid bit to judge whether the wheel speed corresponding to the reverse wheel is valid. When the wheel speed corresponding to the reverse wheel is determined to be valid and the absolute value of the wheel speed of the reverse wheel is greater than a preset wheel speed threshold, it is determined that at least one wheel of the vehicle is in the reverse state.

[0061] Specifically, obtain the wheel speed and its wheel speed valid bit of each wheel, the wheel speed direction and its wheel speed direction valid bit of each wheel, which are monitored in real time by the VCU. Use the wheel speed direction valid bit to judge whether the wheel speed direction of each wheel is valid. When the wheel speed direction valid bit of each wheel is valid and the wheel speed direction of any one wheel is reverse; then use the wheel speed valid bit to judge whether the wheel speed corresponding to the reverse wheel is valid. When the wheel speed valid bit corresponding to the reverse wheel is valid and the absolute value of the wheel speed of the reverse wheel is greater than a preset wheel speed threshold (such as 2 km / h), that is then it is judged that the reverse wheel is in the reverse state. The wheel in the reverse state is also considered to have a reverse trend. In the formula, v wheeli represents the wheel speed of each wheel, that is, v wheelFL , v wheelFR , v wheelRL , v wheelRR .

[0062] In another example, a predetermined wheel reverse trend determination method is used to judge the rotation state of the wheels of a vehicle, including: obtaining the front motor speed, rear motor speed, front motor speed valid bit, and rear motor speed valid bit of the vehicle, using the front motor speed valid bit to judge whether the front motor speed is valid, and using the rear motor speed valid bit to judge whether the rear motor speed is valid; when both the front motor speed and the rear motor speed are determined to be valid and any one of the front motor speed and the rear motor speed is lower than a preset motor speed threshold, it is determined that at least one wheel of the vehicle is in the reverse state.

[0063] Specifically, obtain the front motor speed, rear motor speed, front motor speed valid bit, and rear motor speed valid bit corresponding to the actual vehicle, which are monitored in real time by the VCU. Respectively use the front motor speed valid bit and the rear motor speed valid bit to judge whether the corresponding front motor speed and rear motor speed are valid. When the front motor speed valid bit and the rear motor speed valid bit are valid (that is, the front motor speed and the rear motor speed are valid), and any one of the front motor speed and the rear motor speed, m spdi is lower than a preset motor speed threshold when, that is If so, it is determined that the wheel is in a reverse rotation state, and the wheel in the reverse rotation state is also considered to have a reverse rotation tendency. In the formula, m spdi represents the front motor speed m spdf and the rear motor speed m spdr of any one of the motors. In practical applications, the motor speed threshold can be set to -50 rpm.

[0064] According to the technical solution provided by the embodiment of the present application, use any of the above wheel reverse rotation tendency determination methods to determine whether the wheel is in a reverse rotation state (that is, whether it has a reverse rotation tendency). When it is determined that the vehicle has a wheel reverse rotation phenomenon, control the VCU to issue a wheel reverse rotation flag bit. The wheel reverse rotation flag bit is a data bit usually used in an automotive electronic system to indicate the rotation direction of the wheel. The specific setting of this flag bit may vary depending on different systems and implementation methods, but generally, it can be used to mark whether the wheel is rotating forward or in reverse. When the wheel is moving forward normally, this flag bit may be set to a certain state (for example, logic "0"). When it is detected that the wheel is rotating in reverse (for example, when the vehicle is reversing), this flag bit may be set to another state (for example, logic "1").

[0065] In some embodiments, reset the predetermined torque anti-reverse attenuation coefficient, and use the reset torque anti-reverse attenuation coefficient to adjust the coasting recovery torque of the current vehicle, including: reset the torque anti-reverse attenuation coefficient to 0, and use the reset torque anti-reverse attenuation coefficient to adjust the coasting recovery torque of the current vehicle to 0 to limit the output of the coasting recovery torque.

[0066] Specifically, when it is determined that the vehicle is in a low-adhesion condition and at least one wheel of the vehicle is in a reverse rotation state, that is, when the wheel reverse rotation is recognized by the VCU, at this time, reset the torque anti-reverse attenuation coefficient of the vehicle. For example, set the torque anti-reverse attenuation coefficient to 0, and use the reset torque anti-reverse attenuation coefficient to process the coasting recovery torque of the current vehicle, that is, adjust the coasting recovery torque of the current vehicle to 0 to limit the output of the coasting recovery torque. Optionally, the process of processing the coasting recovery torque using the reset torque anti-reverse attenuation coefficient is as follows:

[0067] T = T coast raw *i = T coast raw *0 = 0 (5)

[0068] Among them, T represents the adjusted coasting recovery torque, T coastraw represents the initial coasting recovery torque, and i represents the reset torque anti-reverse attenuation coefficient.

[0069] It should be noted that the coasting recovery torque refers to the reverse torque exerted by the motor on the wheels during the energy recovery process. This reverse torque helps to slow down the vehicle speed and also converts the rotational ability of the wheels into electrical energy. Therefore, the coasting recovery torque can be considered as the electromagnetic resistance generated when the motor operates as a generator. In the embodiments of the present application, by resetting the torque anti-reversal attenuation coefficient to limit the output of the coasting energy recovery torque, the reverse trend of the vehicle can be slowed down, and the driving stability of the vehicle under low-adhesion conditions can be ensured.

[0070] In some embodiments, after transmitting the adjusted coasting recovery torque to the drive motor for torque control, the method further includes: using a wheel reverse trend determination method to continuously judge the rotation state of the vehicle wheels. When it is judged that none of the vehicle wheels are in the reverse state, the reset torque anti-reversal attenuation coefficient is restored to the target value according to a gradient to control the step-by-step recovery of the coasting recovery torque.

[0071] Specifically, after restricting the output of the coasting recovery torque by resetting the torque anti-reversal attenuation coefficient, the embodiments of the present application will return to the processing procedure of the wheel reverse trend determination method, monitor the wheel reverse trend in real time, and continuously judge the rotation state of the wheels. When the judgment condition for the reverse state corresponding to the wheels is not satisfied, that is, when the wheel reverse flag is not activated, at this time, the torque anti-reversal attenuation coefficient is restored to the target value according to a gradient. For example, the torque anti-reversal attenuation coefficient can be gradually restored from 0 to 1. By controlling the step-by-step recovery of the coasting energy recovery torque through the VCU, it is possible to prevent the sudden increase in negative torque from causing the wheels to reverse and instability again.

[0072] It should be noted that the reset torque anti-reversal attenuation coefficient is restored to the target value step by step according to a preset gradient. That is to say, the torque anti-reversal attenuation coefficient does not instantaneously recover from 0 to 1, but slowly recovers from 0 to 1. The gradient during the recovery process can be set according to actual needs, for example, gradually recovering according to the following gradient: 0, 0.1, 0.3, 0.6, 1. It should be understood that the above gradient recovery method is only an optional method, and the embodiments of the present application do not limit this.

[0073] According to the technical solution provided by the embodiments of the present application, the embodiments of the present application can timely detect the reverse situation of the wheels by obtaining the slip ratio of the vehicle, determining whether the vehicle is in a low-adhesion condition, and using a predetermined method for determining the reverse trend of the wheels to determine whether the wheels are in a reverse state. When it is determined that the vehicle is in a low-adhesion condition and at least one wheel is in a reverse state, the present application adjusts the coasting recovery torque to slow down the reverse trend of the wheels, thereby improving the driving stability and driving safety of the vehicle under low-adhesion conditions. In addition, when the wheels are in reverse, the present application resets the torque anti-reverse attenuation coefficient to adjust the coasting recovery torque. Then, the adjusted coasting recovery torque is transmitted to the drive motor for torque control, thereby slowing down the reverse trend of the wheels and improving the efficiency of coasting energy recovery. Therefore, based on the strategy of real-time monitoring and adjustment, the present application effectively controls the driving state of the vehicle by comprehensively using the state information and control strategy of the vehicle.

[0074] The following is an embodiment of the device of the present application, which can be used to execute the method embodiment of the present application. For the details not disclosed in the embodiment of the device of the present application, please refer to the method embodiment of the present application.

[0075] Figure 2 It is a schematic structural diagram of a vehicle stability control device based on a low-adhesion condition provided by an embodiment of the present application. As Figure 2 shown, the vehicle stability control device based on a low-adhesion condition includes:

[0076] An acquisition module 201, configured to acquire the slip ratio of the current vehicle and determine whether the current vehicle is in a low-adhesion condition based on the slip ratio;

[0077] A judgment module 202, configured to use a predetermined method for determining the reverse trend of the wheels to judge the rotation state of the wheels of the vehicle to determine whether the wheels of the vehicle are in a reverse state when it is monitored that the vehicle triggers the anti-reverse function;

[0078] An adjustment module 203, configured to reset a predetermined torque anti-reverse attenuation coefficient and adjust the coasting recovery torque of the current vehicle by using the reset torque anti-reverse attenuation coefficient when it is determined that the vehicle is in a low-adhesion condition and at least one wheel of the vehicle is in a reverse state;

[0079] A control module 204, configured to transmit the adjusted coasting recovery torque to the drive motor to perform torque control to slow down the reverse trend of the wheels.

[0080] In some embodiments, Figure 2The acquisition module 201 acquires the vehicle's overall vehicle speed, ESC overall vehicle speed, and the wheel speeds of each wheel, and calculates the slip ratio of the vehicle using the overall vehicle speed, ESC overall vehicle speed, and the wheel speeds of each wheel; when the slip ratio of the vehicle is less than a preset slip ratio threshold, it is determined that the current vehicle is in a low-adhesion condition.

[0081] In some embodiments, Figure 2 Before the acquisition module 201 uses a predetermined method for determining the reverse trend of the wheels to judge the rotation state of the vehicle's wheels, it acquires the real-time gear information and gear valid bit of the vehicle, and judges whether the gear information is valid based on the gear valid bit; when the gear information is determined to be valid, it judges whether the gear information is a forward gear, and when it is judged to be a forward gear, it triggers the anti-reverse function of the vehicle.

[0082] In some embodiments, Figure 2 After the acquisition module 201 determines that the current vehicle is in a low-adhesion condition, it acquires the overall vehicle torque, the actual torque of the front motor, and the actual torque of the rear motor, and compares the overall vehicle torque, the actual torque of the front motor, and the actual torque of the rear motor with their respective corresponding torque thresholds. When any one of the overall vehicle torque, the actual torque of the front motor, and the actual torque of the rear motor is less than its corresponding torque threshold, it is determined that the current vehicle is in a coasting energy recovery state.

[0083] In some embodiments, Figure 2 The judgment module 202 acquires the wheel speed, wheel speed direction, wheel speed valid bit, and wheel speed direction valid bit of each wheel, and uses the wheel speed direction valid bit to judge whether the wheel speed direction is valid. When the wheel speed direction is determined to be valid and the wheel speed direction of any one wheel is the reverse direction; it uses the wheel speed valid bit to judge whether the wheel speed corresponding to the reverse wheel is valid. When the wheel speed corresponding to the reverse wheel is determined to be valid and the absolute value of the wheel speed of the reverse wheel is greater than a preset wheel speed threshold, it is determined that at least one wheel of the vehicle is in a reverse state.

[0084] In some embodiments, Figure 2 The judgment module 202 acquires the rotational speed of the front motor, the rotational speed of the rear motor, the rotational speed valid bit of the front motor, and the rotational speed valid bit of the rear motor, and uses the rotational speed valid bit of the front motor to judge whether the rotational speed of the front motor is valid, and uses the rotational speed valid bit of the rear motor to judge whether the rotational speed of the rear motor is valid; when both the rotational speed of the front motor and the rotational speed of the rear motor are determined to be valid and any one of the rotational speeds of the front motor and the rotational speed of the rear motor is lower than a preset motor rotational speed threshold, it is determined that at least one wheel of the vehicle is in a reverse state.

[0085] In some embodiments, Figure 2The adjustment module 203 resets the torque anti-reverse attenuation coefficient to 0, and uses the reset torque anti-reverse attenuation coefficient to adjust the coasting recovery torque of the current vehicle to 0 to limit the output of the coasting recovery torque.

[0086] In some embodiments, Figure 2 After the control module 204 transmits the adjusted coasting recovery torque to the drive motor for torque control, it continuously judges the rotation state of the vehicle's wheels by using the wheel reverse trend determination method. When it is judged that none of the vehicle's wheels are in the reverse state, the reset torque anti-reverse attenuation coefficient is restored to the target value according to the gradient to control the step-by-step recovery of the coasting recovery torque.

[0087] It should be understood that the magnitudes of the sequence numbers of the steps in the above embodiments do not mean the order of execution. The order of execution of each process should be determined according to its function and internal logic, and should not constitute any limitation to the implementation process of the embodiments of the present application.

[0088] The embodiment of the present application also provides a new energy vehicle, including a vehicle controller, a motor controller, a drive motor and a transmission system; the vehicle controller is used to implement the steps of the above vehicle stability control method based on low-adhesion conditions to send the adjusted coasting recovery torque to the motor controller; the motor controller is used to perform torque control on the drive motor through the transmission system according to the adjusted coasting recovery torque.

[0089] Figure 3 is a schematic structural diagram of the electronic device 3 provided by the embodiment of the present application. As Figure 3 shown, the electronic device 3 of this embodiment includes: a processor 301, a memory 302, and a computer program 303 stored in the memory 302 and executable on the processor 301. When the processor 301 executes the computer program 303, the steps in the above various method embodiments are implemented. Alternatively, when the processor 301 executes the computer program 303, the functions of each module / unit in the above various device embodiments are implemented.

[0090] Exemplarily, the computer program 303 can be divided into one or more modules / units. One or more modules / units are stored in the memory 302 and executed by the processor 301 to complete the present application. One or more modules / units can be a series of computer program instruction segments capable of performing specific functions, and the instruction segments are used to describe the execution process of the computer program 303 in the electronic device 3.

[0091] The electronic device 3 can be a desktop computer, a notebook, a palm computer, a cloud server and other electronic devices. The electronic device 3 may include, but is not limited to, the processor 301 and the memory 302. Those skilled in the art can understand, Figure 3This is merely an example of the electronic device 3, which does not constitute a limitation on the electronic device 3. It may include more or fewer components than those shown in the figure, or combine certain components, or have different components. For example, the electronic device may also include input / output devices, network access devices, buses, etc.

[0092] The processor 301 may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or the processor may also be any conventional processor, etc.

[0093] The memory 302 may be an internal storage unit of the electronic device 3. For example, the hard disk or memory of the electronic device 3. The memory 302 may also be an external storage device of the electronic device 3. For example, a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card, etc. equipped on the electronic device 3. Further, the memory 302 may also include both an internal storage unit and an external storage device of the electronic device 3. The memory 302 is used to store computer programs and other programs and data required by the electronic device. The memory 302 may also be used to temporarily store data that has been output or will be output.

[0094] Those skilled in the art can clearly understand that for the convenience and simplicity of description, only the above division of each functional unit and module is used for illustration. In actual applications, the above functions can be allocated to different functional units and modules as needed, that is, the internal structure of the device is divided into different functional units or modules to complete all or part of the functions described above. Each functional unit and module in the embodiment can be integrated in a processing unit, or each unit can exist physically alone, or two or more units can be integrated in one unit. The above integrated unit can be implemented in the form of hardware or in the form of a software functional unit. In addition, the specific names of each functional unit and module are only for the convenience of mutual distinction and do not limit the protection scope of this application. The specific working processes of the units and modules in the above system can refer to the corresponding processes in the foregoing method embodiments and will not be elaborated here.

[0095] In the above embodiments, the descriptions of each embodiment have their own focuses. For parts not detailed or recorded in a certain embodiment, reference may be made to the relevant descriptions of other embodiments.

[0096] Those of ordinary skill in the art can realize that the units and algorithm steps of each example described in combination with the embodiments disclosed herein can be implemented by electronic hardware, or by a combination of computer software and electronic hardware. Whether these functions are executed in hardware or software depends on the specific application and design constraints of the technical solution. A professional technician can use different methods for each specific application to implement the described functions, but such implementation should not be considered to exceed the scope of this application.

[0097] In the embodiments provided in this application, it should be understood that the disclosed device / computer device and method can be implemented in other ways. For example, the device / computer device embodiments described above are merely illustrative. For example, the division of modules or units is only a logical function division. In actual implementation, there may be other division methods. Multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the displayed or discussed couplings or direct couplings or communication connections to each other can be through some interfaces. The indirect couplings or communication connections of devices or units can be in electrical, mechanical or other forms.

[0098] The units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units. That is, they can be located in one place, or distributed to multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0099] In addition, the functional units in each embodiment of this application can be integrated in a processing unit, or each unit can exist physically alone, or two or more units can be integrated in one unit. The above integrated units can be implemented in the form of hardware or in the form of software functional units.

[0100] When the integrated module / unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on such understanding, to implement all or part of the processes in the above-mentioned embodiment methods of this application, it can also be completed by instructing relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium. When the computer program is executed by a processor, the steps of the above-mentioned various method embodiments can be implemented. The computer program can include computer program code, and the computer program code can be in the form of source code, object code, executable file, or some intermediate form, etc. The computer-readable medium can include: any entity or device that can carry computer program code, recording medium, USB flash drive, mobile hard disk, magnetic disk, optical disc, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signal, telecommunication signal, and software distribution medium, etc. It should be noted that the content included in the computer-readable medium can be appropriately increased or decreased according to the requirements of legislation and patent practice within the jurisdiction. For example, in some jurisdictions, according to legislation and patent practice, the computer-readable medium does not include electrical carrier signals and telecommunication signals.

[0101] The above embodiments are only used to illustrate the technical solutions of this application, rather than to limit them; although this application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the various embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. A vehicle stability control method based on low-adhesion working conditions, characterized in that: include: obtaining a current slip ratio of the vehicle, and determining whether the vehicle is currently in a low-adhesion operating condition based on the slip ratio; When the vehicle is monitored to have triggered the anti-reverse function, the predetermined wheel reversal trend determination method is used to determine the rotation state of the vehicle's wheels to determine whether the vehicle's wheels are in a reversal state; When it is determined that the vehicle is in a low-adhesion operating condition and at least one wheel of the vehicle is in a reverse rotation state, a predetermined torque anti-reverse rotation attenuation coefficient is reset, and the current coasting recovery torque of the vehicle is adjusted using the reset torque anti-reverse rotation attenuation coefficient; transmitting the adjusted coasting recovery torque to the drive motor to perform torque control to slow down the reverse rotation tendency of the wheel; The method of determining the rotation state of the wheels of the vehicle by using a predetermined wheel reversal tendency determination method includes: Obtaining the wheel speed, wheel speed direction, wheel speed valid bit, and wheel speed direction valid bit of each wheel, and using the wheel speed direction valid bit to determine whether the wheel speed direction is valid, when the wheel speed direction is determined to be valid and the wheel speed direction of any wheel is in a reverse direction; The wheel speed validity position is used to determine whether the wheel speed corresponding to the reversed wheel is valid. When the wheel speed corresponding to the reversed wheel is determined to be valid and the absolute value of the wheel speed of the reversed wheel is greater than a preset wheel speed threshold, it is determined that at least one wheel of the vehicle is in a reverse state.

2. The method according to claim 1, characterized in that The obtaining of the current slip ratio of the vehicle and determining whether the vehicle is currently in a low-adhesion operating condition based on the slip ratio include: Obtaining the vehicle's entire speed, ESC vehicle speed, and wheel speed of each wheel, and calculating the vehicle's slip rate using the vehicle's entire speed, ESC vehicle speed, and wheel speed of each wheel; and determining that the vehicle is currently in a low-attachment operating condition when the vehicle's slip rate is less than a preset slip rate threshold.

3. The method according to claim 1, characterized in that Before determining the rotation state of the wheels of the vehicle using a predetermined wheel reversal tendency determination method, the method further includes: Acquiring real-time gear information and a gear valid position of the vehicle, and determining whether the gear information is valid based on the gear valid position; When the gear information is determined to be valid, it is determined whether the gear information is a forward gear, and when it is determined to be a forward gear, an anti-reverse function of the vehicle is triggered.

4. The method according to claim 2, characterized in that After determining that the vehicle is currently in the low-load operating condition, the method further includes: The whole vehicle torque, the actual torque of the front motor, and the actual torque of the rear motor of the vehicle are obtained, and the whole vehicle torque, the actual torque of the front motor, and the actual torque of the rear motor are respectively compared with their corresponding torque thresholds. When any one of the whole vehicle torque, the actual torque of the front motor, and the actual torque of the rear motor is less than its corresponding torque threshold, it is determined that the vehicle is currently in a coasting energy recovery state.

5. The method according to claim 1, wherein The method of determining the rotation state of the wheels of the vehicle by using a predetermined wheel reversal tendency determination method includes: Obtaining a front motor speed, a rear motor speed, a front motor speed valid bit, and a rear motor speed valid bit of the vehicle, determining whether the front motor speed is valid using the front motor speed valid bit, and determining whether the rear motor speed is valid using the rear motor speed valid bit; When both the front motor speed and the rear motor speed are determined to be valid, and any one of the front motor speed and the rear motor speed is lower than a preset motor speed threshold, it is determined that at least one wheel of the vehicle is in a reversing state.

6. The method according to claim 1, characterized in that The resetting of the predetermined torque anti-reverse attenuation coefficient and adjusting the current coasting recovery torque of the vehicle using the reset torque anti-reverse attenuation coefficient includes: The torque anti-reverse attenuation coefficient is reset to 0, and the current coasting recovery torque of the vehicle is adjusted to 0 using the reset torque anti-reverse attenuation coefficient to limit the output of the coasting recovery torque.

7. The method according to claim 6, characterized in that After transmitting the adjusted coasting recovery torque to the drive motor to perform torque control, the method further includes: The wheel reversal trend determination method is used to continuously determine the rotation state of the vehicle's wheels. When it is determined that none of the vehicle's wheels are in a reversal state, the reset torque anti-reversal attenuation coefficient is restored to the target value according to the gradient to control the coasting recovery torque to recover step by step.

8. A vehicle stability control device based on low-adhesion working conditions, characterized in that: include: an acquisition module configured to acquire a current slip ratio of the vehicle and determine whether the vehicle is currently in a low-adhesion operating condition based on the slip ratio; a judgment module configured to, when monitoring that the vehicle triggers the anti-reverse function, use a predetermined wheel reversal trend judgment method to judge the rotation state of the vehicle's wheels to determine whether the vehicle's wheels are in a reversal state; an adjustment module configured to, when determining that the vehicle is in a low-adhesion operating condition and at least one wheel of the vehicle is in a reversing state, reset a predetermined torque anti-reversal attenuation coefficient, and adjust the current coasting recovery torque of the vehicle using the reset torque anti-reversal attenuation coefficient; a control module configured to transmit the adjusted coasting recovery torque to the drive motor to perform torque control so as to slow down the reverse rotation tendency of the wheel; Among them, the judgment module is used to obtain the wheel speed, wheel speed direction, wheel speed valid bit and wheel speed direction valid bit of each wheel, and use the wheel speed direction valid bit to judge whether the wheel speed direction is valid. When the wheel speed direction is judged to be valid and the wheel speed direction of any of the wheels is in a reverse direction; use the wheel speed valid bit to judge whether the wheel speed corresponding to the reversed wheel is valid. When the wheel speed corresponding to the reversed wheel is judged to be valid and the absolute value of the wheel speed of the reversed wheel is greater than a preset wheel speed threshold, it is determined that at least one wheel of the vehicle is in a reverse state.

9. A new energy vehicle, characterized in that: Including vehicle controller, motor controller, drive motor and transmission system; The vehicle controller is used to implement the method according to any one of claims 1 to 7, so as to send the adjusted coasting recovery torque to the motor controller; The motor controller is used to control the torque of the drive motor through the transmission system according to the adjusted coasting recovery torque.

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