Vehicle control method, device, vehicle and storage medium

Abstract

An embodiment of the present application provides a vehicle control method, device, vehicle, and storage medium. The method is applied to a vehicle with distributed drive, and the method includes: when it is monitored that the vehicle is driving on a two-way road surface, obtaining the current actual torque of a first wheel among the coaxial wheels of the vehicle; determining the expected torque of a second wheel among the coaxial wheels based on the current actual torque of the first wheel; controlling the second wheel to operate according to the expected torque of the second wheel. In the embodiment of the present application, when the vehicle is driving on a specified road condition, the torque of the high-grip side wheels will decrease as the actual torque of the low-grip side wheels decreases. At this time, the yaw angular acceleration of the vehicle approaches zero, and the yaw angular velocity will not suddenly increase and always remains at a low level. Therefore, the control difficulty of the driver for the vehicle can be reduced, the probability of safety accidents caused by excessive yaw angular velocity can be reduced, and the driving safety of the vehicle can be increased.

Description

Technical Field

[0001] The present application relates to the technical field of automobiles, and more specifically, to a vehicle control method, device, vehicle, and storage medium. Background Art

[0002] Yaw rate refers to the deflection of a vehicle around the vertical axis, and the magnitude of this deflection represents the stability of the vehicle. Among them, the greater the yaw rate, the less stable the vehicle.

[0003] When the coaxial wheels of a vehicle are respectively driving on road surfaces with significantly different adhesion coefficients, since the wheels driving on the road surface with a lower adhesion coefficient will slip, the torque decreases, and the torque of the wheels driving on the road surface with a higher adhesion coefficient remains unchanged. At this time, the yaw rate of the vehicle will increase, resulting in a decrease in the stability of the vehicle. Summary of the Invention

[0004] Embodiments of the present application provide a vehicle control method, device, vehicle, and storage medium.

[0005] In a first aspect, embodiments of the present application provide a vehicle control method. The method is applied to a vehicle, and the vehicle adopts distributed drive. The method includes: when it is monitored that the vehicle is driving on a split road surface, obtaining the current actual torque of a first wheel among the coaxial wheels of the vehicle; based on the current actual torque of the first wheel, determining the expected torque of a second wheel among the coaxial wheels, where the adhesion coefficient of the road surface on which the first wheel is driving is less than the adhesion coefficient of the road surface on which the second wheel is driving, and the current actual torque of the second wheel is greater than the expected torque of the second wheel; controlling the second wheel to work according to the expected torque of the second wheel.

[0006] In a second aspect, embodiments of the present application provide a vehicle control device. The device includes: a torque acquisition module, configured to obtain the current actual torque of a first wheel among the coaxial wheels of the vehicle when it is monitored that the vehicle is driving on a split road surface; a torque determination module, configured to determine the expected torque of a second wheel among the coaxial wheels based on the current actual torque of the first wheel, where the adhesion coefficient of the road surface on which the first wheel is driving is less than the adhesion coefficient of the road surface on which the second wheel is driving, and the current actual torque of the second wheel is greater than the expected torque of the second wheel; a control module, configured to control the second wheel to work according to the expected torque of the second wheel.

[0007] In a third aspect, embodiments of the present application provide a vehicle. The vehicle includes a processor and a memory. The memory stores computer program instructions, and the computer program instructions are called by the processor to execute the vehicle control method as described in the first aspect.

[0008] Fourthly, an embodiment of the present application provides a computer-readable storage medium. The computer-readable storage medium stores program codes, and the program codes are called by a processor to execute the vehicle control method as described in the first aspect.

[0009] Fifthly, an embodiment of the present application provides a computer program product. When the product is executed, it can implement the vehicle control method as described in the first aspect.

[0010] An embodiment of the present application provides a vehicle control method. When it is detected that the vehicle is driving on a specified road condition (the coaxial wheels are respectively driving on a road surface with a high adhesion coefficient and a road surface with a low adhesion coefficient), the vehicle determines the expected torque of the high-adhesion-side wheel (i.e., the second wheel) based on the actual torque of the low-adhesion-side wheel (i.e., the first wheel). Then, the high-adhesion-side wheel is controlled according to the expected torque of the high-adhesion-side wheel. Since the expected torque of the high-adhesion-side wheel is less than the actual torque of the high-adhesion-side wheel before control, that is, the torque of the high-adhesion-side wheel will decrease as the actual torque of the low-adhesion-side wheel decreases. At this time, the yaw angular acceleration of the vehicle approaches zero, and the yaw angular velocity will not suddenly increase and always remains at a low level. Therefore, the control difficulty of the driver for the vehicle can be reduced, the occurrence probability of safety accidents caused by too large yaw angular velocity can be reduced, and the driving safety of the vehicle can be increased. Description of the Drawings

[0011] 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 the description of the embodiments. Obviously, the following drawings are only some embodiments of the present application. For those skilled in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0012] Figure 1 It is a schematic diagram of a vehicle driving on an open road provided by the related art.

[0013] Figure 2 It is a relationship diagram of torque and vehicle speed, and yaw angular velocity and vehicle speed when the vehicle provided by the related art is driving on an open road.

[0014] Figure 3 It is a schematic diagram of a vehicle driving on an open road provided by an embodiment of the present application.

[0015] Figure 4 It is a relationship diagram of torque and vehicle speed, and yaw angular velocity and vehicle speed when the vehicle provided by an embodiment of the present application is driving on an open road.

[0016] Figure 5 It is a schematic diagram of a vehicle provided by an embodiment of the present application.

[0017] Figure 6It is a flowchart of a vehicle control method provided by an embodiment of the present application.

[0018] Figure 7 It is a flowchart of a vehicle control method provided by another embodiment of the present application.

[0019] Figure 8 It is a block diagram of a vehicle control device provided by an embodiment of the present application.

[0020] Figure 9 It is a functional block diagram of a vehicle provided by an embodiment of the present application.

[0021] Figure 10 It is a structural block diagram of a computer-readable storage medium provided by an embodiment of the present application. Detailed implementation manners

[0022] The following details the implementation manners of the present application. Examples of the implementation manners are shown in the accompanying drawings, where the same or similar reference numerals denote the same or similar elements or elements with the same or similar functions throughout. The implementation manners described below with reference to the accompanying drawings are exemplary only for explaining the present application and should not be construed as a limitation of the present application.

[0023] To enable those skilled in the art of the present technology to better understand the solutions of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative efforts shall fall within the protection scope of the present application.

[0024] The following introduces the technical terms related to the embodiments of the present application.

[0025] Split friction road surface: A road surface where the adhesion coefficients of the coaxial wheels of a vehicle vary significantly. For example, if the adhesion coefficient of the road surface traveled by the first wheel among the coaxial wheels is x1, and the adhesion coefficient of the road surface traveled by the second wheel among the coaxial wheels is x2, and the absolute value of the difference between x1 and x2 is greater than a pre-set adhesion coefficient threshold a, it indicates that the road surface on which the vehicle is currently traveling is a split friction road surface.

[0026] Adhesion coefficient: It refers to the ratio of the adhesion force to the normal force of the wheel, and can be approximately considered as the road surface friction coefficient. On a road surface with a higher adhesion coefficient (such as a gravel road or an asphalt road), a vehicle is not easily skidded and is safe to drive. On a road surface with a lower adhesion coefficient (such as a snow-covered road or an ice surface), a vehicle is easily skidded and there are relatively large potential safety hazards.

[0027] Torque: The moment that causes an object to rotate, equal to the product of force and the length of the lever arm. The international unit is Newton-meter (N·m).

[0028] Through long-term research, the inventors found that for a vehicle with distributed drive, when it is driving on a divided road, the wheels driving on the ground with a low adhesion coefficient (hereinafter referred to as low-adhesion-side wheels) will lose traction due to slipping, while the wheels driving on the ground with a high adhesion coefficient (hereinafter referred to as high-adhesion-side wheels) still move forward according to the original torque. At this time, the vehicle is affected by a yaw force, generating a yaw angular acceleration and a yaw angular velocity. At this time, it is difficult for the driver to control the vehicle, increasing the probability of a safety accident for the vehicle.

[0029] Reference Figure 1 , which shows a working schematic diagram of a vehicle provided by the related art. Among them, vehicle 110 is a four-wheel drive vehicle. Wheels 111 and 112 are driving on the ground with a high adhesion coefficient, and wheels 113 and 114 are driving on the ground with a low adhesion coefficient. At this time, vehicle 110 will generate the yaw angular acceleration and yaw angular velocity as shown in the figure, making it difficult for the driver to control vehicle 110.

[0030] Reference Figure 2 , which shows a torque-speed relationship diagram of a vehicle provided by the related art. Among them, curve 1 represents the driver-requested torque, curve 2 represents the actual torque of the high-adhesion-side wheels, curve 3 represents the actual torque of the low-adhesion-side wheels, and curve 4 represents the yaw angular velocity of the vehicle. According to Figure 2 it can be seen that when the vehicle is driving on a divided road, the actual torque of the low-adhesion-side wheels will decrease significantly. With the torque of the high-adhesion-side wheels remaining unchanged, the yaw angular velocity of the vehicle increases significantly as the actual torque of the low-adhesion-side wheels decreases.

[0031] To address the problems of the existing technology, the inventors have studied a vehicle control method, device, vehicle, and storage medium. When it is detected that the vehicle is driving on a specified road condition (coaxial wheels are driving on roads with high and low adhesion coefficients respectively), the vehicle determines the desired torque of the high-adhesion-side wheels (i.e., the second wheels) based on the actual torque of the low-adhesion-side wheels (i.e., the first wheels), and then controls the high-adhesion-side wheels according to the desired torque of the high-adhesion-side wheels. Since the desired torque of the high-adhesion-side wheels is less than the actual torque of the high-adhesion-side wheels before control, that is, the torque of the high-adhesion-side wheels will decrease as the actual torque of the low-adhesion-side wheels decreases. At this time, the yaw angular acceleration of the vehicle approaches zero, and the yaw angular velocity does not increase suddenly, but always remains at a low level. Therefore, the control difficulty for the driver can be reduced, the probability of a safety accident caused by an excessive yaw angular velocity can be decreased, and the driving safety of the vehicle can be increased.

[0032] Reference Figure 3, which shows a working schematic diagram of a vehicle provided by the related art. Among them, vehicle 310 is a four-wheel drive vehicle. Wheel 311 and wheel 312 are running on the ground with a high adhesion coefficient, and wheel 313 and wheel 314 are running on the ground with a low adhesion coefficient. According to the vehicle control scheme provided by the inventor, the torque of the high-adhesion side wheels is controlled. At this time, the yaw angular acceleration of vehicle 310 approaches zero, and the yaw angular velocity will not continue to increase, and vehicle 310 can continue to drive normally.

[0033] Reference Figure 4 , which shows the torque-speed relationship diagram of the vehicle during operation provided by the embodiment of the present application. Among them, curve 1 represents the driver-requested torque, curve 2 represents the actual torque of the high-adhesion side wheels, curve 3 represents the actual torque of the low-adhesion side wheels, and curve 4 represents the yaw angular velocity of the vehicle. According to Figure 4 It can be seen that when the vehicle is driving on an open road, the actual torque of the low-adhesion side wheels will decrease significantly. When the torque of the high-adhesion side wheels is controlled by using the vehicle control method provided by the embodiment of the present application, the torque of the high-adhesion side wheels will decrease as the torque of the low-adhesion side wheels decreases, and the yaw angular velocity of the vehicle will not suddenly increase and will always be maintained at a low level, which is beneficial for the driver to control the vehicle.

[0034] Please refer to Figure 5 , which shows a schematic diagram of vehicle 500 provided by an embodiment of the present application. This vehicle 500 adopts distributed drive. This vehicle 500 is an electric vehicle.

[0035] In some embodiments, vehicle 500 is a four-wheel drive vehicle, that is, the four wheels of vehicle 500 are respectively controlled by four motors. In other embodiments, vehicle 500 is a three-wheel drive vehicle, where the two wheels on the rear axle are controlled by different motors, and the two wheels on the front axle are controlled by the same motor.

[0036] In the embodiment of the present application, vehicle 500 has a torque control function. When vehicle 500 is driving on an open road, it controls the torque of the high-adhesion side to decrease, avoiding a sudden increase in the yaw angular velocity of the vehicle, which is beneficial for the driver to control the vehicle and reduces the probability of safety accidents caused by excessive yaw angular velocity, increasing the driving safety of vehicle 500. In the embodiment of the present application, vehicle 500 also has a road condition monitoring function to monitor whether vehicle 500 is driving on an open road.

[0037] Please refer to Figure 6 , which shows a flowchart of a vehicle control method provided by an embodiment of the present application. This method is applied to a vehicle, and this method includes the following steps.

[0038] Step S601, when it is monitored that the vehicle is driving on an open road, obtain the current actual torque of the first wheel among the coaxial wheels of the vehicle.

[0039] A split friction road surface refers to a road surface where the difference in the adhesion coefficients of the road surfaces traveled by two wheels in a coaxial wheel pair is greater than a first threshold value.

[0040] The first threshold value is set based on experiments or experience, and the embodiments of the present application do not limit this. Exemplarily, the first threshold value is 0.5. In a specific example, the first adhesion coefficient is 0.1, the second adhesion coefficient is 0.8, and the absolute value of the difference between the two is 0.7, which is greater than the above first threshold value, indicating that the vehicle is currently traveling on a specified road condition.

[0041] Torque is the product of the torsion force and the distance from the acting point to the direction of the torsion force. Its measurement methods include at least one of the following: strain type torque measurement, piezomagnetic torque measurement, and optoelectronic torque measurement. The embodiments of the present application only take the optoelectronic torque measurement method as an example for elaboration. Specifically, two disk gratings are fixed on the rotating shaft of the first wheel of the vehicle. When the rotating shaft does not bear torque, the bright and dark areas of the two gratings exactly block each other, and no light from the light source passes through the grating to irradiate the photosensitive element, and the photosensitive element has no output signal; when the rotating shaft bears torque, the deformation of the rotating shaft will cause a relative rotation angle between the two gratings, and part of the light passes through the grating to irradiate the photosensitive element, and the photosensitive element generates an output signal. The greater the torque, the greater the torsional angle, the greater the light flux passing through the grating, and the greater the output signal. Furthermore, the torque can be calculated based on the output signal of the photosensitive element.

[0042] It should be noted that a road surface where the difference in the adhesion coefficients of the road surfaces traveled by two wheels in a coaxial wheel pair is less than or equal to the first threshold value can be called a uniform road surface. The embodiments of the present application do not provide a matrix control scheme for the high-adhesion side wheels when the vehicle is traveling on a uniform road surface.

[0043] Step S602: Determine the expected torque of the second wheel in the coaxial wheel pair based on the current actual torque of the first wheel.

[0044] The adhesion coefficient of the road surface traveled by the first wheel is less than the adhesion coefficient of the road surface traveled by the second wheel, and the current actual torque of the second wheel is greater than the expected torque of the second wheel. The determination method of the expected torque of the second wheel will be elaborated in the following embodiments.

[0045] In the embodiments of the present application, when the vehicle is traveling on a split friction road surface, the vehicle will control the torque of the high-adhesion side wheel (i.e., the second wheel) based on the actual torque of the low-adhesion side wheel (i.e., the first wheel). Specifically, the vehicle controls the torque of the high-adhesion side wheel to decrease following the decrease of the torque of the low-adhesion side wheel, so that the yaw angular velocity of the vehicle will not suddenly increase and will always be maintained at a low level, which is beneficial for the driver to control the vehicle, reduces the probability of safety accidents caused by the yaw angular velocity, and increases the driving safety of the vehicle.

[0046] In some embodiments, step S602 may be alternatively implemented as the following sub-steps.

[0047] Step S602a: Obtain the operating parameters of the first wheel.

[0048] The operating parameters of the first wheel include at least one of the following: angular acceleration information of the first motor, moment of inertia information of the first motor, angular acceleration information of the first wheel, moment of inertia information of the first wheel, and transmission ratio between the first wheel and the first motor. The first motor is the motor used to control the first wheel.

[0049] The angular acceleration information of the first motor refers to the physical quantity that describes the rate of change of the magnitude and direction of the angular velocity of the first motor relative to time. In some embodiments, an accelerometer is provided on the first motor to measure the angular acceleration information of the first motor. Specifically, the accelerometer includes an angular velocity measurement module and a differential circuit. The angular velocity signal of the first motor is measured by the angular velocity measurement module, and the measured angular velocity signal is differentiated by the differential circuit to obtain the angular acceleration information of the first motor.

[0050] The moment of inertia information of the first motor is a measure of the inertia (the property of a rotating object to maintain its uniform circular motion or rest) when the first motor rotates. The vehicle can measure the moment of inertia information of the first motor by at least one of the following methods: the three-wire pendulum method, the torsion pendulum method, the compound pendulum method, etc.

[0051] The angular acceleration information of the first wheel refers to the physical quantity that describes the rate of change of the magnitude and direction of the angular velocity of the first wheel relative to time. In some embodiments, an accelerometer is provided on the first wheel to measure the angular acceleration information of the first wheel.

[0052] The moment of inertia information of the first wheel is a measure of the inertia (the property of a rotating object to maintain its uniform circular motion or rest) when the first wheel rotates. The vehicle can measure the moment of inertia information of the first wheel by at least one of the following methods: the three-wire pendulum method, the torsion pendulum method, the compound pendulum method, etc.

[0053] The transmission ratio refers to the ratio of the angular velocities of two rotating components in a mechanism. The transmission ratio between the first wheel and the first motor is also the ratio of the angular velocity of the first wheel to the angular velocity of the first motor. In some embodiments, angular velocity sensors are respectively provided on the first motor and the first wheel. The angular velocity of the first motor is measured by the angular velocity sensor provided on the first motor, and the angular velocity of the first wheel is measured by the angular velocity sensor provided on the first wheel. Then, the ratio between the angular velocity of the first wheel and the angular velocity of the first motor is determined as the transmission ratio between the first wheel and the first motor.

[0054] Step S602b: Determine the loss value based on the working parameters of the first wheel.

[0055] There are losses in both the first motor and the first wheel for the current actual torque of the first wheel. To quantify this loss, the vehicle determines the loss value based on the working parameters of the first wheel.

[0056] In some embodiments, step S602b can be alternatively implemented as the following sub-steps: Determine the product between the angular acceleration information of the first motor and the moment of inertia information of the first motor as the first loss component; Determine the product between the angular acceleration information of the first wheel and the moment of inertia information of the first wheel as an intermediate value, and determine the product of the intermediate value and the transmission ratio of the first wheel as the second loss component; Determine the sum of the first loss component and the second loss component as the loss value.

[0057] The first loss component, which is also the angular momentum of the first motor, is a quantity describing the rotational state of the first motor. The intermediate value, which is also the angular momentum of the first wheel, is a quantity describing the rotational state of the first wheel.

[0058] Step S602c: Obtain the current actual torque of the first wheel, the loss value, and the preset compensation value to determine the desired torque of the second wheel.

[0059] The vehicle determines the sum of the specified difference and the preset compensation value as the desired torque of the second wheel. The specified difference is the difference between the current actual torque of the first wheel and the loss value. The preset compensation value is a deviation value determined based on the vehicle speed and the change in yaw rate, and it is set according to experiments or experience.

[0060] In some embodiments, the desired torque of the second wheel is calculated through the following calculation formula.

[0061]

[0062] where M H refers to the desired torque of the second wheel, M L refers to the current actual torque of the first wheel, d mot refers to the angular acceleration information of the first motor, J mot refers to the moment of inertia information of the first motor, d wheel refers to the angular acceleration information of the first wheel, J wheel refers to the moment of inertia information of the first wheel, ikin refers to the transmission ratio, and offset refers to the preset compensation value.

[0063] Step S603: Control the second wheel to work according to the desired torque of the second wheel.

[0064] In summary, for the technical solution provided in the embodiments of the present application, when it is detected that the vehicle is driving on a specified road condition (the coaxial wheels are respectively driving on a road surface with a high adhesion coefficient and a road surface with a low adhesion coefficient), the vehicle determines the expected torque of the high-adhesion side wheel (i.e., the second wheel) based on the actual torque of the low-adhesion side wheel (i.e., the first wheel), and then controls the high-adhesion side wheel according to the expected torque of the high-adhesion side wheel. Since the expected torque of the high-adhesion side wheel is less than the actual torque of the high-adhesion side wheel before control, that is, the torque of the high-adhesion side wheel will decrease as the actual torque of the low-adhesion side wheel decreases. At this time, the yaw angular acceleration of the vehicle approaches zero, and the yaw angular velocity will not suddenly increase and always remains at a low level. Therefore, the control difficulty of the driver for the vehicle can be reduced, the probability of safety accidents caused by excessive yaw angular velocity can be reduced, and the driving safety of the vehicle can be increased.

[0065] Please refer to Figure 7 , which shows a flowchart of a vehicle control method provided by an embodiment of the present application. This method is applied to a vehicle and includes the following steps.

[0066] Step S701, when it is detected that the vehicle is driving on a split road surface, obtain the yaw angular velocity information of the vehicle.

[0067] The yaw angular velocity information is used to characterize the yaw angular acceleration and the yaw angular velocity of the vehicle.

[0068] The yaw angular velocity of the vehicle refers to the deflection of the vehicle around the vertical axis. The magnitude of this deflection represents the stability of the vehicle. The greater the yaw angular velocity of the vehicle, the less stable the vehicle is. The smaller the yaw angular velocity of the vehicle, the more stable the vehicle is.

[0069] The yaw angular acceleration of the vehicle is used to determine the stage in which the yaw angular velocity is located. When the yaw angular acceleration of the vehicle is greater than zero, it indicates that the yaw angular velocity is in the acceleration stage; when the yaw angular acceleration of the vehicle is less than zero, it indicates that the yaw angular velocity is in the deceleration stage; when the yaw angular acceleration of the vehicle is equal to zero, it indicates that the yaw angular velocity is in uniform motion.

[0070] In some embodiments, a yaw angular accelerometer is provided on the vehicle to measure the yaw angular acceleration information. Specifically, the yaw angular accelerometer includes a yaw angular velocity measurement module and a differential circuit. The yaw angular velocity signal of the vehicle is measured by the yaw angular velocity measurement module, and the measured yaw angular velocity signal is differentiated by the differential circuit to obtain the yaw angular acceleration information.

[0071] Step S702, when the yaw angular velocity information of the vehicle meets a preset condition, obtain the current actual torque of the first wheel.

[0072] The preset conditions include: the yaw rate is greater than a first preset value; and / or, the yaw angular acceleration is greater than a second preset value. The first preset value is set based on experiments or experience, and the second preset value is used to represent that the yaw rate is in the acceleration stage. Exemplarily, the first preset value is 8 and the second preset value is 0.

[0073] In the embodiments of the present application, by performing subsequent torque control steps for the high-adhesion side wheels when the yaw rate information meets the preset conditions, the power consumption of the vehicle can be saved.

[0074] Step S703: Determine the desired torque of the second wheel based on the current actual torque of the first wheel.

[0075] The current actual torque of the second wheel is greater than the desired torque of the second wheel.

[0076] Step S704: Determine the control duration according to the yaw rate.

[0077] The control duration is positively correlated with the yaw rate. That is, the greater the yaw rate, the longer the control duration; the smaller the yaw rate, the shorter the control duration.

[0078] In some embodiments, the vehicle looks up the control duration corresponding to the yaw rate in the first mapping table. The first mapping table includes the mapping relationship between the yaw rate and the control duration. The first mapping table can be set based on experiments or experience. Specifically, in the first experimental stage, the first mapping table is set by technicians according to experience, and it can be iterated according to the experimental results during subsequent experimental processes. In other embodiments, the vehicle determines the control duration through the first functional relationship and the yaw rate. The first functional relationship represents the functional relationship between the yaw rate and the control duration, and it can be obtained by fitting experimental data.

[0079] Step S705: Control the second wheel to work according to the desired torque of the second wheel during the control period.

[0080] The time length of the control period is the control duration. In the embodiments of the present application, determining the control duration according to the yaw rate can improve the control accuracy.

[0081] Step S706: After the control period ends, control the torque of the second wheel to increase.

[0082] Wherein, the unit time increment of the torque of the second wheel is negatively correlated with the yaw rate. That is, the greater the yaw rate, the smaller the unit time increment of the torque of the second wheel; the smaller the yaw rate, the greater the unit time increment of the torque of the second wheel.

[0083] In some embodiments, the vehicle looks up the unit time increment of the torque of the second wheel corresponding to the yaw rate in the second mapping table. The second mapping table includes the mapping relationship between the yaw rate and the unit time increment of the torque of the second wheel. The second mapping table can be set according to experiments or experience. Specifically, in the first experimental stage, the second mapping table is set by technicians according to experience, and it can be iterated according to the experimental results during subsequent experimental processes. In other embodiments, the vehicle determines the unit time increment of the torque of the second wheel through the second functional relationship and the yaw rate. The second functional relationship represents the functional relationship between the yaw rate and the unit time increment of the torque of the second wheel, and it can be obtained by fitting experimental data.

[0084] In the above manner, when controlling the torque of the high-grip side wheels, it is allowed that the torque of the high-grip side wheels gradually increases according to the magnitude of the yaw rate. On the premise of ensuring the driving safety of the vehicle, the acceleration requirement of the driver for the vehicle is met.

[0085] Step S707, control the second wheel to work according to the increased torque of the second wheel.

[0086] In summary, the technical solution provided by the embodiments of the present application also executes subsequent torque control steps for the high-grip side wheels when the yaw rate information meets the preset conditions, which can avoid providing torque control for the high-grip side wheels under unnecessary circumstances, effectively save the power consumption of the vehicle, and also determine the control duration of the torque for the high-grip side wheels according to the yaw rate, improve the control accuracy, and also control the torque of the high-grip side wheels to gradually increase according to the yaw rate after the control period ends. On the premise of ensuring the driving safety of the vehicle, the acceleration requirement of the driver for the vehicle is met.

[0087] The embodiments of the present application provide a torque control solution for high-grip side wheels when the vehicle is driving on a specified road condition. In order to improve the control accuracy, it is necessary to ensure that the vehicle is driving on the specified road condition. The implementation manner of monitoring whether the vehicle is driving on the specified road condition will be described below.

[0088] In some embodiments, the vehicle monitors whether it is driving on a split road surface through the following steps: obtain the slip ratios corresponding to the coaxial wheels of the vehicle respectively. The slip ratios corresponding to the coaxial wheels respectively include a first slip ratio and a second slip ratio; when the absolute value of the difference between the first slip ratio and the second slip ratio is greater than a second threshold, determine that the vehicle is driving on a split road surface.

[0089] In the case where the vehicle is a four-motor drive vehicle, the vehicle can obtain the slip ratios corresponding to the front axle wheels respectively, can also obtain the slip ratios corresponding to the rear axle wheels respectively, and can also obtain the slip ratios corresponding to the front axle wheels respectively and the slip ratios corresponding to the rear axle wheels respectively at the same time. In the case where the vehicle is a three-motor drive vehicle, the vehicle can obtain the slip ratios corresponding to the rear axle wheels respectively.

[0090] When the wheel exerts traction or braking force, relative movement occurs between the wheel and the ground. Among them, the slip ratio of the wheel is used to characterize the proportion of the sliding component in the wheel movement. The larger the slip ratio of the wheel, the smaller the adhesion coefficient of the road surface on which the wheel travels. The smaller the slip ratio of the wheel, the larger the adhesion coefficient of the road surface on which the wheel travels.

[0091] In some embodiments, wheel speed sensors are provided on the wheels of the vehicle for detecting the wheel speed. After the vehicle obtains the wheel speed and the vehicle speed, the slip ratio of the wheel is calculated through the following calculation formula.

[0092]

[0093] Among them, u represents the vehicle speed, u w represents the wheel speed, and s represents the slip ratio.

[0094] In other embodiments, angular velocity sensors are provided on the wheels of the vehicle for detecting the angular velocity of the wheels. After the vehicle obtains the angular velocity of the wheels and the vehicle speed, the slip ratio of the wheel is calculated through the following calculation formula.

[0095]

[0096] Among them, u represents the vehicle speed, w represents the angular velocity of the wheel, r represents the radius of the wheel, and s represents the slip ratio.

[0097] The absolute value of the difference between the slip ratios corresponding to the coaxial wheels respectively can be calculated through the following mathematical formula.

[0098] y = |y1 - y2|.

[0099] Among them, y1 represents the first slip ratio among the slip ratios corresponding to the coaxial wheels respectively, and y2 represents the second slip ratio among the slip ratios corresponding to the coaxial wheels respectively.

[0100] The second threshold is set according to experiments or experience, and the embodiments of the present application do not limit this. Exemplarily, the second threshold is 1. In a specific example, the first slip ratio is 3.6, the second slip ratio is 4.7, and the absolute value of the difference between the two is 1.1, which is greater than the above second threshold, indicating that the vehicle is currently traveling on a split road surface.

[0101] In some embodiments, the vehicle obtains the slip ratios corresponding to the coaxial wheels at preset time intervals to ensure real-time monitoring of the vehicle. The preset time can be set according to experiments or experience, and the embodiments of the present application do not limit this. Exemplarily, the preset time is 5 seconds. In other embodiments, the vehicle obtains the slip ratios corresponding to the coaxial wheels when it detects that the yaw angular acceleration is greater than a preset value. The preset value is used to represent that the yaw angular velocity is in the acceleration stage. Optionally, the preset value is zero. Generally, when the vehicle is driving on a specified road condition, the yaw angular velocity will increase, and at this time the yaw angular acceleration is greater than zero. Therefore, when it is detected that the yaw angular acceleration is greater than zero, it indicates that the vehicle is probably driving on a two-way road surface. At this time, it is used to monitor whether the vehicle is driving on a two-way road surface to avoid the high power consumption problem caused by continuous monitoring.

[0102] It should be noted that after it is determined that the vehicle is driving on a two-way road surface, if the first slip ratio is less than the second slip ratio, the wheel with the first slip ratio is determined as the second wheel, and the wheel with the second slip ratio is determined as the first wheel; if the first slip ratio is greater than the second slip ratio, the wheel with the first slip ratio is determined as the first wheel, and the wheel with the second slip ratio is determined as the second wheel.

[0103] In other embodiments, after the vehicle obtains the slip ratios corresponding to the coaxial wheels, it looks up the adhesion coefficient corresponding to the first slip ratio and the adhesion coefficient corresponding to the second slip ratio in the mapping table between the slip ratio and the adhesion coefficient, and then detects whether the absolute value of the difference between the two is greater than a first threshold. If the absolute value of the difference between the two is greater than the first threshold, it indicates that the vehicle is driving on a two-way road surface. If the absolute value of the difference between the two is less than or equal to the first threshold, it indicates that the vehicle is not driving on a two-way road surface. The mapping table between the slip ratio and the adhesion coefficient can be preset according to experiments or experience, and the embodiments of the present application do not limit this.

[0104] Please refer to Figure 8 , which shows a structural block diagram of a vehicle control device 800 provided by an embodiment of the present application. This device is applied to a vehicle, and the vehicle adopts distributed drive. The vehicle control device 800 includes: a torque acquisition module 810, a torque determination module 820, and a control module 830.

[0105] The torque acquisition module 810 is configured to obtain the current actual torque of the first wheel among the coaxial wheels of the vehicle when it is monitored that the vehicle is driving on a two-way road surface. The torque determination module 820 is configured to determine the desired torque of the second wheel among the coaxial wheels based on the current actual torque of the first wheel, where the adhesion coefficient of the road surface on which the first wheel travels is less than the adhesion coefficient of the road surface on which the second wheel travels, and the current actual torque of the second wheel is greater than the desired torque of the second wheel. The control module 830 is configured to control the second wheel to work according to the desired torque of the second wheel.

[0106] In summary, for the technical solution provided in the embodiment of the present application, when it is detected that the vehicle is driving on a specified road condition (the coaxial wheels are respectively driving on a road surface with a high adhesion coefficient and a road surface with a low adhesion coefficient), the vehicle determines the expected torque of the high-adhesion side wheel (i.e., the second wheel) based on the actual torque of the low-adhesion side wheel (i.e., the first wheel), and then controls the high-adhesion side wheel according to the expected torque of the high-adhesion side wheel. Since the expected torque of the high-adhesion side wheel is less than the actual torque of the high-adhesion side wheel before control, that is, the torque of the high-adhesion side wheel will decrease as the actual torque of the low-adhesion side wheel decreases. At this time, the yaw angular acceleration of the vehicle approaches zero, and the yaw angular velocity will not suddenly increase and always remains at a low level. Therefore, the control difficulty of the driver for the vehicle can be reduced, the probability of safety accidents caused by excessive yaw angular velocity can be reduced, and the driving safety of the vehicle can be increased.

[0107] In some embodiments, the torque determination module 820 is configured to obtain the working parameters of the first wheel. The working parameters of the first wheel include at least one of the following: the angular acceleration information of the first motor, the moment of inertia information of the first motor, the angular acceleration information of the first wheel, the moment of inertia information of the first wheel, and the transmission ratio of the first wheel. Wherein, the first motor is the motor used to control the first wheel; determine the loss value based on the working parameters of the first wheel; obtain the current actual torque, loss value, and preset compensation value of the first wheel to determine the expected torque of the second wheel.

[0108] In some embodiments, the torque determination module 820 is configured to determine the product between the angular acceleration information of the first motor and the moment of inertia information of the first motor as the first loss component; determine the product between the angular acceleration information of the first wheel and the moment of inertia information of the first wheel as an intermediate value, and determine the intermediate value and the transmission ratio of the first wheel as the second loss component; determine the sum of the first loss component and the second loss component as the loss value.

[0109] In some embodiments, the torque acquisition module 810 is configured to obtain the yaw angular velocity information of the vehicle when it is detected that the vehicle is driving on a specified road condition. The yaw angular velocity information is used to characterize the yaw angular acceleration and the yaw angular velocity of the vehicle; when the yaw angular velocity information of the vehicle meets a preset condition, obtain the current actual torque of the first wheel. Wherein, the preset condition includes: the yaw angular velocity is greater than a first preset value; and / or, the yaw angular acceleration is greater than a second preset value.

[0110] In some embodiments, the control module 830 is configured to: determine the control duration according to the yaw angular velocity, where the control duration has a positive correlation with the yaw angular velocity; control the second wheel to work according to the expected torque of the second wheel during the control period, and the time length of the control period is the control duration.

[0111] In some embodiments, the torque determination module 820 is further configured to control an increase in the torque of the second wheel after the control period ends, where the increase in the torque of the second wheel per unit time is negatively correlated with the yaw angular velocity. The control module 830 is configured to control the operation of the second wheel according to the increased torque of the second wheel.

[0112] In some embodiments, the device further includes a road condition monitoring module (not shown in the figure). The road condition monitoring module is configured to obtain the slip ratios corresponding to the coaxial wheels of the vehicle, and the slip ratios corresponding to the coaxial wheels include a first slip ratio and a second slip ratio; when the absolute value of the difference between the first slip ratio and the second slip ratio is greater than a second threshold, it is determined that the vehicle is traveling on a split road surface.

[0113] Those skilled in the art can clearly understand that for the convenience and brevity of description, the specific working processes of the above-described device and modules can refer to the corresponding processes in the foregoing method embodiments, and will not be described herein again.

[0114] In several embodiments provided in the present application, the coupling between modules can be electrical, mechanical, or other forms of coupling.

[0115] In addition, in each embodiment of the present application, the various functional modules can be integrated in one processing module, or each module can exist physically alone, or two or more modules can be integrated in one module. The above-mentioned integrated modules can be implemented in the form of hardware or in the form of software functional modules.

[0116] As Figure 9 shown, the present application example further provides a vehicle 900, which includes a processor 910, a memory 920, and at least one lidar 930. Among them, the memory 920 stores computer program instructions.

[0117] The processor 910 may include one or more processing cores. The processor 910 connects various parts within the entire battery management system through various interfaces and circuits. By running or executing instructions, programs, code sets, or instruction sets stored in the memory 920, and by invoking data stored in the memory 920, it performs various functions of the battery management system and processes data. Optionally, the processor 910 may be implemented in at least one hardware form of digital signal processing (DSP), field-programmable gate array (FPGA), or programmable logic array (PLA). The processor 910 may integrate one or a combination of several of a central processing unit 910 (CPU), a graphics processing unit 910 (GPU), and a modem, etc. Among them, the CPU mainly processes the operating system, user interface, application programs, etc.; the GPU is responsible for rendering and drawing display content; the modem is used to process wireless communication. It can be understood that the above-mentioned modem may not be integrated into the processor 910 and may be implemented separately through a communication chip.

[0118] The memory 920 may include a random access memory 920 (RAM), and may also include a read-only memory 920 (Read-Only Memory). The memory 920 can be used to store instructions, programs, code, code sets, or instruction sets. The memory 920 may include a program storage area and a data storage area. Among them, the program storage area may store instructions for implementing the operating system, instructions for implementing at least one function (such as touch function, sound playback function, image playback function, etc.), instructions for implementing the following various method examples, etc. The data storage area may also store data created during the use of the vehicle (such as phone book, audio and video data, chat record data), etc.

[0119] Please refer to Figure 10 , which shows that the embodiment of the present application further provides a computer-readable storage medium 1000. Computer program instructions 1010 are stored in the computer-readable storage medium 1000, and the computer program instructions 1010 can be called by a processor to execute the methods described in the above embodiments.

[0120] The computer-readable storage medium 1000 can be an electronic memory such as a flash memory, EEPROM (electrically erasable programmable read-only memory), EPROM, a hard disk, or a ROM. Optionally, the computer-readable storage medium 1000 includes a non-transitory computer-readable storage medium. The computer-readable storage medium 1000 has a storage space for computer program instructions 1010 that execute any of the method steps S in the above-described method. These computer program instructions 1010 can be read from or written to one or more computer program products. The computer program instructions 1010 can be compressed in a suitable form.

[0121] The above are only the preferred examples of the present application and do not impose any formal limitations on the present application. Although the present application has been disclosed above with preferred examples, it is not intended to limit the present application. Any person skilled in the art can make some modifications or refinements to equivalent examples with equivalent changes by using the technical content disclosed above without departing from the technical solution scope of the present application. However, as long as it does not depart from the technical solution content of the present application, any brief modifications, equivalent changes, and refinements made to the above examples based on the technical essence of the present application still fall within the scope of the technical solution of the present application.

Claims

1. A vehicle control method, characterized in that, the method is applied to a vehicle with distributed drive, and the method includes: when it is monitored that the vehicle is driving on a two-way road surface, obtaining the current actual torque of a first wheel among the coaxial wheels of the vehicle; obtaining the working parameters of the first wheel, where the working parameters of the first wheel include at least one of the following: angular acceleration information of the first motor, moment of inertia information of the first motor, angular acceleration information of the first wheel, moment of inertia information of the first wheel, transmission ratio between the first wheel and the first motor; wherein, the first motor is the motor for controlling the first wheel; determining a loss value based on the working parameters of the first wheel; obtaining the current actual torque of the first wheel, the loss value, and a preset compensation value to determine the desired torque of a second wheel, where the adhesion coefficient of the road surface on which the first wheel travels is less than the adhesion coefficient of the road surface on which the second wheel travels, and the current actual torque of the second wheel is greater than the desired torque of the second wheel; controlling the second wheel to work according to the desired torque of the second wheel.

2. The method according to claim 1, characterized in that, the determining the loss value based on the working parameters of the first wheel includes: determining the product between the angular acceleration information of the first motor and the moment of inertia information of the first motor as a first loss component; determining the product between the angular acceleration information of the first wheel and the moment of inertia information of the first wheel as an intermediate value, and determining the intermediate value and the transmission ratio of the first wheel as a second loss component; determining the sum of the first loss component and the second loss component as the loss value.

3. The method according to claim 1, characterized in that, the obtaining the current actual torque of a first wheel among the coaxial wheels of the vehicle when it is monitored that the vehicle is driving on a two-way road surface includes: when it is monitored that the vehicle is driving on a specified road condition, obtaining the yaw angular velocity information of the vehicle, where the yaw angular velocity information is used to characterize the yaw angular acceleration and the yaw angular velocity of the vehicle; when the yaw angular velocity information of the vehicle meets a preset condition, obtaining the current actual torque of the first wheel; wherein, the preset condition includes: the yaw angular velocity is greater than a first preset value; or / and, the yaw angular acceleration is greater than a second preset value.

4. The method according to claim 3, characterized in that, the controlling the second wheel to work according to the desired torque of the second wheel includes: determining a control duration according to the yaw angular velocity, where the control duration has a positive correlation with the yaw angular velocity; controlling the second wheel to work according to the desired torque of the second wheel within a control period, and the time length of the control period is the control duration.

5. The method according to claim 4, characterized in that, after the controlling the second wheel to work according to the desired torque of the second wheel within the control period, it further includes: After the end of the control period, control the torque of the second wheel to increase, wherein the increase in the torque of the second wheel per unit time is negatively correlated with the yaw angular velocity; Control the second wheel to work according to the increased torque of the second wheel.

6. The method according to any one of claims 1 to 5, characterized in that, the method further includes: obtain the slip ratios corresponding to the coaxial wheels respectively, and the slip ratios corresponding to the coaxial wheels respectively include a first slip ratio and a second slip ratio; When the absolute value of the difference between the first slip ratio and the second slip ratio is greater than a second threshold, determine that the vehicle is traveling on the split road surface.

7. A vehicle control device, characterized in that, the device includes: a torque acquisition module, configured to acquire the current actual torque of the first wheel among the coaxial wheels of the vehicle when it is monitored that the vehicle is traveling on a split road surface; a torque determination module, configured to acquire the working parameters of the first wheel, and the working parameters of the first wheel include at least one of the following: the angular acceleration information of the first motor, the moment of inertia information of the first motor, the angular acceleration information of the first wheel, the moment of inertia information of the first wheel, and the transmission ratio between the first wheel and the first motor; wherein the first motor is the motor for controlling the first wheel; determine the loss value based on the working parameters of the first wheel; obtain the current actual torque of the first wheel, the loss value, and a preset compensation value to determine the desired torque of the second wheel, wherein the adhesion coefficient of the road surface on which the first wheel travels is less than the adhesion coefficient of the road surface on which the second wheel travels, and the current actual torque of the second wheel is greater than the desired torque of the second wheel; a control module, configured to control the second wheel to work according to the desired torque of the second wheel.

8. A vehicle, characterized in that, the vehicle includes a processor and a memory, and the memory stores computer program instructions, and the computer program instructions are called by the processor to execute the vehicle control method according to any one of claims 1-6.

9. A computer-readable storage medium, characterized in that, the computer-readable storage medium stores program codes, and the program codes are called by the processor to execute the vehicle control method according to any one of claims 1-6.

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