Method, device, vehicle and storage medium for controlling vehicle start

Abstract

The present application provides a method, device, vehicle and storage medium for controlling vehicle start. When the launch mode is triggered, the vehicle will accelerate and start. During the process of accelerating and starting the vehicle, the ground friction and power distribution on the front and rear wheels may be different, which will cause the slip rate of the front and rear wheels to change at different rates. When the rate of change of the slip rate of the front wheel is greater than that of the front wheel, the longitudinal grip of the front wheel will decrease, resulting in the inability of the vehicle to launch. Therefore, based on the first change rate and the second change rate, the vehicle adjusts the initial proportional relationship between the front and rear axle motors in the output torque, and then adjusts the current output torque corresponding to each of the front and rear axle motors to control the change rate of the slip rate of the front and rear wheels to be close. In this way, the vehicle can effectively convert the power generated by the engine into forward traction, which helps to control the vehicle to launch in a standard manner, while also avoiding power loss caused by slippage.

Description

Technical Field

[0001] The present application relates to the field of vehicles, and more specifically, to a method, a device, a vehicle and a storage medium for controlling vehicle starting in the field of vehicles. Background Art

[0002] The vehicle's launch start process refers to the process in which the vehicle reaches maximum acceleration at the moment of starting and quickly increases its speed in a short distance. When the vehicle's launch start function is used, the vehicle can achieve greater acceleration at the moment of starting, which can give the driver more driving pleasure.

[0003] At present, the control process of the launch control in the related art may encounter uneven vehicle acceleration or even vehicle loss of control, resulting in the vehicle being unable to launch, which will seriously affect the driver's driving pleasure and driving safety.

[0004] Therefore, there is an urgent need for a method for controlling the vehicle to start, so as to control the vehicle to perform a standard launch start. Summary of the invention

[0005] The present application provides a method, device, vehicle and storage medium for controlling vehicle start, wherein the method can control the vehicle to perform a standard launch start, thereby improving the stability and acceleration performance of the vehicle's launch start.

[0006] In a first aspect, a method for controlling vehicle starting is provided, the method comprising: when a launch control mode in a vehicle is triggered and the vehicle accelerates to start, obtaining a first change rate of a slip rate of a front wheel and a second change rate of a slip rate of a rear wheel in the vehicle; when the first change rate is greater than the second change rate, adjusting an initial proportional relationship between an output torque of a front axle motor and a rear axle motor in the vehicle based on the first change rate and the second change rate; and adjusting current output torques corresponding to the front axle motor and the rear axle motor respectively based on the adjusted proportional relationship to perform launch control on the vehicle.

[0007] In the above technical solution, when the launch mode in the vehicle is triggered, the vehicle will accelerate and start. During the process of accelerating and starting the vehicle, the ground friction and power distribution on the front and rear wheels may be different, which will cause the slip rate of the front and rear wheels to change at different speeds. When the rate of change of the slip rate of the front wheel is greater than the rate of change of the slip rate of the front wheel, the increase in the slip rate of the front wheel will reduce the longitudinal grip of the front wheel, and the weight of the front part of the vehicle moves forward, which makes it difficult for the vehicle to drive according to the driver's intention when accelerating, and it is impossible to launch and start. Especially on slippery roads, it may cause the vehicle to lose control, seriously affecting the stability and handling of the vehicle. Therefore, in this method, the vehicle adjusts the initial proportional relationship between the front axle motor and the rear axle motor in the output torque based on the first change rate and the second change rate, and then adjusts the current output torque corresponding to the front axle motor and the rear axle motor based on the adjusted proportional relationship. This is because the launch start of the vehicle is closely related to the output torque of the front and rear axle motors (front axle motor and rear axle motor) in the vehicle, and the output torque of the front and rear axle motors is related to the initial proportional relationship. By adjusting the current output torques of the front and rear axle motors, the slip rates of the front and rear wheels can be controlled to be close. In this way, the vehicle can effectively convert the power generated by the engine into forward traction, which helps control the vehicle to perform a standard launch start, while also avoiding power loss caused by slip.

[0008] In combination with the first aspect, in some possible implementations, based on the first change rate and the second change rate, the initial proportional relationship between the front axle motor and the rear axle motor in the vehicle in terms of output torque is adjusted, including: determining a first increase in the first change rate relative to the second change rate; determining the product of the first increase and a first numerical value corresponding to the front axle motor in the initial proportional relationship as a second numerical value, and reducing the first numerical value by the second numerical value; determining the product of the first increase and a third numerical value corresponding to the rear axle motor in the initial proportional relationship as a fourth numerical value, and increasing the third numerical value by the fourth numerical value.

[0009] In the above technical solution, determining the first increase range of the first change rate relative to the second change rate can quantify how much faster the change speed of the slip rate of the front wheel is compared to the change speed of the slip rate of the rear wheel. Normally, when the change speed of the slip rate of the front wheel is greater than the change speed of the slip rate of the rear wheel, the vehicle reduces the first value corresponding to the front axle motor in the initial proportional relationship, and increases the third value corresponding to the rear axle motor in the initial proportional relationship. The rate of change of the slip rate of the front wheel and the rate of change of the slip rate of the rear wheel will affect the output torque of the front and rear axle motors. The slip rate can reflect the adhesion condition between the tire and the ground, and the torque output of the front and rear axle motors can be adjusted based on the adhesion condition of the tire. Therefore, in this method, the vehicle determines the product of the first increase amplitude and the first numerical value corresponding to the front axle motor in the initial proportional relationship as the second numerical value, and reduces the first numerical value by the second numerical value to accurately obtain the fifth numerical value corresponding to the front axle motor in the adjusted proportional relationship; determines the product of the first increase amplitude and the third numerical value corresponding to the rear axle motor in the initial proportional relationship as the fourth numerical value, and increases the third numerical value by the fourth numerical value to accurately obtain the sixth numerical value corresponding to the rear axle motor in the adjusted proportional relationship.

[0010] In combination with the first aspect and the above-mentioned implementation methods, in some possible implementation methods, the current output torques corresponding to the front axle motor and the rear axle motor are adjusted based on the adjusted proportional relationship, including: determining the sum of the current output torque of the front axle motor and the current output torque of the rear axle motor as the total output torque; allocating a first output torque to the front axle motor and a second output torque to the rear axle motor from the total output torque based on the adjusted proportional relationship and the total output torque; adjusting the current output torque of the front axle motor to the first output torque, and adjusting the current output torque of the rear axle motor to the second output torque.

[0011] In the above technical solution, the maximum torque capacity (total output torque) output by the front and rear axle motors is determined. After obtaining the adjusted proportional relationship, the vehicle can accurately allocate output torque (first output torque) to the front axle motor and allocate output torque (second output torque) to the rear axle motor based on the adjusted proportional relationship and the total output torque. Therefore, the vehicle adjusts the current output torque of the front axle motor to the first output torque, and adjusts the current output torque of the rear axle motor to the second output torque. In this way, the change speed of the slip rate of the front and rear wheels can be close, so that the vehicle can effectively convert the power generated by the engine into forward traction, which helps to control the vehicle to perform a standard launch start.

[0012] In combination with the first aspect and the above-mentioned implementation methods, in some possible implementation methods, the method also includes: in response to the triggering operation of the launch start mode, adjusting the total braking force of multiple wheels in the vehicle to a braking force threshold, and controlling the front axle motor and the rear axle motor to output their respective corresponding initial torques, wherein the initial torque is obtained based on the preset output torques corresponding to the front axle motor and the rear axle motor and the initial proportional relationship between the front axle motor and the rear axle motor in the output torque; releasing the total braking force within a preset time length, and based on a preset gradient, increasing the initial torques corresponding to the front axle motor and the rear axle motor to the corresponding target torques to control the vehicle to accelerate and start.

[0013] In the above technical solution, before the vehicle accelerates and starts, the vehicle can respond to the triggering operation of the launch start mode and adjust the total braking force of multiple wheels in the vehicle to the braking force threshold to control the braking force of the vehicle to be greater than the driving force, and control the vehicle to remain stationary. At the same time, the vehicle controls the front axle motor and the rear axle motor to output their respective initial torques. This is for self-test and preheating, so that the vehicle can perform necessary inspections and preparations to ensure that it can work normally when the vehicle starts. Further, the total braking force is released within a preset time, and based on a preset gradient, the initial torque corresponding to each of the front axle motor and the rear axle motor is increased to the corresponding target torque. This is to immediately obtain the maximum traction by quickly increasing the output torque of the front and rear axle motors in a short time, so that the vehicle can quickly accelerate and start. In addition, releasing the total braking force within a preset time and increasing the output torque based on a preset gradient can avoid the risk of loss of control of the vehicle due to excessive power when starting, and can ensure driving safety.

[0014] In combination with the first aspect and the above-mentioned implementation methods, in certain possible implementation methods, the method for determining the initial proportional relationship between the front axle motor and the rear axle motor in the output torque includes: detecting whether the longitudinal acceleration of the vehicle is lower than a preset acceleration; when the longitudinal acceleration is lower than the preset acceleration, detecting whether the front wheels and the rear wheels in the vehicle are slipping at a uniform speed; when the front wheels and the rear wheels are slipping at a uniform speed, obtaining the initial proportional relationship between the front axle motor and the rear axle motor in the output torque.

[0015] In the above technical solution, at the moment of launch, the wheels in the vehicle need to overcome the maximum static friction in a stationary state with a larger driving force in order to accelerate as quickly as possible. When the front and rear wheels slip at a constant speed with a lower longitudinal acceleration, it indicates that the traction provided by the wheels is equal to the driving force, that is, the maximum available traction is reached. The torque distribution ratio relationship (initial ratio relationship) at this time can ensure that the vehicle outputs the maximum power (driving force) without losing traction. Therefore, when the longitudinal acceleration of the vehicle is low and the front and rear wheels slip at a constant speed, the initial ratio relationship between the output torque of the front axle motor and the rear axle motor is obtained, and it is used in the acceleration and starting process of the vehicle.

[0016] In combination with the first aspect and the above-mentioned implementation methods, in some possible implementation methods, the method for determining the preset output torque corresponding to the front axle motor and the rear axle motor includes: when the longitudinal acceleration of the vehicle is lower than the preset acceleration and the front wheels and the rear wheels in the vehicle are slipping at a constant speed, obtaining the total output torque of the front axle motor and the rear axle motor, and the rotational speed of the front wheels and the rear wheels; determining the adhesion coefficient of the road surface on which the vehicle is located based on the total output torque and the rotational speed, and a first preset correspondence, the first preset correspondence being used to describe the correspondence between the total output torque of the front axle motor and the rear axle motor, and the rotational speed of the front wheels and the rear wheels when the front wheels and the rear wheels are slipping at a constant speed, and the road surface adhesion coefficient; determining the preset output torque based on the adhesion coefficient and a second preset correspondence, the second preset correspondence being used to describe the correspondence between the road surface adhesion coefficient and the preset output torque corresponding to the front axle motor and the rear axle motor.

[0017] In the above technical solution, there is a corresponding relationship (first preset corresponding relationship) between the total output torque of the front axle motor and the rear axle motor, and the rotation speed of the front wheels and the rear wheels when the front wheels and the rear wheels slip at a constant speed, and the road adhesion coefficient. Therefore, the vehicle can accurately determine the adhesion coefficient of the road surface on which the vehicle is located based on the total output torque and the rotation speed, and the first preset corresponding relationship. There is a corresponding relationship (second preset corresponding relationship) between the road adhesion coefficient and the preset output torque corresponding to the front axle motor and the rear axle motor. Therefore, the vehicle can accurately determine the preset output torque corresponding to the front axle motor and the rear axle motor based on the adhesion coefficient and the second preset corresponding relationship.

[0018] In combination with the first aspect and the above-mentioned implementation methods, in some possible implementation methods, the method also includes: when the first change rate is less than the second change rate, determining the flatness index of the road surface on which the vehicle is located; when the flatness index is higher than a preset index, adjusting the tire pressure of the rear wheels of the vehicle based on the flatness index and the preset index; when the flatness index is lower than the preset index, reducing the opening of the accelerator pedal in the vehicle based on the difference between the second change rate and the first change rate.

[0019] In the above technical solution, when the rate of change of the slip rate of the front wheel (first rate of change) is less than the rate of change of the slip rate of the rear wheel (second rate of change), the rapid slip of the rear wheel may cause the rear of the vehicle to lose traction, while the front wheel still tries to maintain grip, which will cause the center of gravity of the vehicle to move backward and may cause the rear of the vehicle to lift. Therefore, the vehicle needs the rear wheel to maintain grip. However, there are many factors that affect the grip of the rear wheel. When the first rate of change is less than the second rate of change, the method determines the flatness index of the road surface on which the vehicle is located. When the flatness index is higher than the preset index, the tire pressure of the rear wheel in the vehicle is adjusted based on the flatness index and the preset index, so that the contact area between the rear wheel tire and the ground can be increased, thereby improving traction. This can make the vehicle more stable when accelerating. When the flatness index is lower than the preset index, the vehicle reduces the opening of the accelerator pedal in the vehicle, which can help the engine reduce the output torque, thereby reducing the slip rate of the rear wheel. This helps to improve the grip of the rear wheel and improve the acceleration efficiency and handling stability of the vehicle.

[0020] In a second aspect, a device for controlling vehicle starting is provided, the device comprising: an acquisition module, used to acquire a first change rate of the slip rate of the front wheels and a second change rate of the slip rate of the rear wheels in the vehicle when a launch mode in the vehicle is triggered and the vehicle accelerates to start; an adjustment module, used to: when the first change rate is greater than the second change rate, adjust the initial proportional relationship between the front axle motor and the rear axle motor in the vehicle in terms of output torque based on the first change rate and the second change rate; and adjust the current output torques corresponding to the front axle motor and the rear axle motor respectively based on the adjusted proportional relationship to perform launch control on the vehicle.

[0021] In combination with the second aspect, in some possible implementations, the device also includes: a determination module, used to determine a first increase range of the first change rate relative to the second change rate; the adjustment module, specifically used to: determine the product of the first increase range and the first numerical value corresponding to the front axle motor in the initial proportional relationship as the second numerical value, and reduce the first numerical value by the second numerical value; determine the product of the first increase range and the third numerical value corresponding to the rear axle motor in the initial proportional relationship as a fourth numerical value, and increase the third numerical value by the fourth numerical value.

[0022] In combination with the second aspect and the above-mentioned implementation methods, in some possible implementation methods, the determination module is specifically used to: determine the sum of the current output torque of the front axle motor and the current output torque of the rear axle motor as the total output torque; based on the adjusted proportional relationship and the total output torque, allocate a first output torque to the front axle motor from the total output torque, and allocate a second output torque to the rear axle motor; the adjustment module is also specifically used to adjust the current output torque of the front axle motor to the first output torque, and adjust the current output torque of the rear axle motor to the second output torque.

[0023] In combination with the second aspect and the above-mentioned implementation methods, in some possible implementation methods, the adjustment module is also used to: in response to the triggering operation of the launch start mode, adjust the total braking force of multiple wheels in the vehicle to a braking force threshold, and control the front axle motor and the rear axle motor to output their respective corresponding initial torques, where the initial torque is based on the preset output torques corresponding to the front axle motor and the rear axle motor and the initial proportional relationship between the front axle motor and the rear axle motor in the output torque; release the total braking force within a preset time length, and based on a preset gradient, increase the initial torques corresponding to the front axle motor and the rear axle motor to the corresponding target torques to control the vehicle to accelerate and start.

[0024] In combination with the second aspect and the above-mentioned implementation methods, in some possible implementation methods, the device also includes: a detection module, used to: detect whether the longitudinal acceleration of the vehicle is lower than a preset acceleration; when the longitudinal acceleration is lower than the preset acceleration, detect whether the front wheels and the rear wheels in the vehicle are slipping at a constant speed; the acquisition module is specifically used to obtain the initial proportional relationship between the front axle motor and the rear axle motor in the output torque when the front wheels and the rear wheels are slipping at a constant speed.

[0025] In combination with the second aspect and the above-mentioned implementation methods, in some possible implementation methods, the acquisition module is specifically used to obtain the total output torque of the front axle motor and the rear axle motor, and the rotational speed of the front wheels and the rear wheels when the longitudinal acceleration of the vehicle is lower than the preset acceleration and the front wheels and the rear wheels in the vehicle are slipping at a constant speed; the determination module is specifically used to: determine the adhesion coefficient of the road surface on which the vehicle is located based on the total output torque and the rotational speed, and a first preset correspondence, the first preset correspondence is used to describe the correspondence between the total output torque of the front axle motor and the rear axle motor, and the rotational speed of the front wheels and the rear wheels when the front wheels and the rear wheels are slipping at a constant speed, and the road adhesion coefficient; determine the preset output torque based on the adhesion coefficient and the second preset correspondence, the second preset correspondence is used to describe the correspondence between the road adhesion coefficient and the preset output torque corresponding to the front axle motor and the rear axle motor.

[0026] In combination with the second aspect and the above-mentioned implementation methods, in some possible implementation methods, the determination module is also used to determine the flatness index of the road surface on which the vehicle is located when the first change rate is less than the second change rate; the adjustment module is also used to: when the flatness index is higher than a preset index, adjust the tire pressure of the rear wheels of the vehicle based on the flatness index and the preset index; when the flatness index is lower than the preset index, reduce the opening of the accelerator pedal in the vehicle based on the difference between the second change rate and the first change rate.

[0027] In a third aspect, a vehicle is provided, comprising a memory and a processor. The memory is used to store executable program code, and the processor is used to call and run the executable program code from the memory, so that the vehicle executes the method in the first aspect or any possible implementation of the first aspect.

[0028] In a fourth aspect, a computer-readable storage medium is provided, which stores an executable program code. When the executable program code runs on a computer, the computer executes the method in the above-mentioned first aspect or any possible implementation of the first aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is a schematic diagram of a scenario of using a vehicle provided in an embodiment of the present application;

[0030] Figure 2 is a schematic flow chart of a method for controlling vehicle starting provided by an embodiment of the present application;

[0031] Figure 3 It is a schematic diagram of a vehicle launch start provided by an embodiment of the present application;

[0032] Figure 4 It is a schematic diagram of controlling the front and rear axle motors to output respective corresponding initial torques provided in an embodiment of the present application;

[0033] Figure 5 It is a structural schematic diagram of a device for controlling vehicle starting provided in an embodiment of the present application;

[0034] Figure 6 It is a structural schematic diagram of a vehicle provided in an embodiment of the present application. DETAILED DESCRIPTION

[0035] The technical solution in the present application will be described clearly and in detail below in conjunction with the accompanying drawings. In the description of the embodiments of the present application, unless otherwise specified, " / " means or, for example, A / B can mean A or B: "and / or" in the text is only a description of the association relationship of associated objects, indicating that there can be three relationships, for example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, in the description of the embodiments of the present application, "multiple" means two or more than two.

[0036] In the following, the terms "first" and "second" are used for descriptive purposes only and are not to be understood as suggesting or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features.

[0037] Figure 1 It is a schematic diagram of a scenario of using a vehicle provided in an embodiment of the present application.

[0038] For example, Figure 1 As shown, vehicle A performs launch control on vehicle A in response to the driver's triggering operation of the launch mode in vehicle A. At present, the related technology may encounter uneven vehicle acceleration or even vehicle loss of control during the launch control process, which will seriously affect the driving safety of the driver.

[0039] In order to solve the above problems, the present application proposes a method for controlling the vehicle to start, so as to control the vehicle to perform a standard launch start. For details, please refer to the following Figure 2 .

[0040] Figure 2 It is a schematic flowchart of a method for controlling vehicle starting provided in an embodiment of the present application.

[0041] It should be understood that the method for controlling vehicle starting provided in the embodiment of the present application is applied to Figure 1 The vehicle (vehicle A) in the vehicle, specifically, the method for controlling vehicle starting can also be applied to a controller in the vehicle.

[0042] For example, Figure 2 As shown, the method 200 includes:

[0043] Step 201 : when a launch mode in a vehicle is triggered and the vehicle starts accelerating, the vehicle obtains a first change rate of a slip ratio of a front wheel and a second change rate of a slip ratio of a rear wheel in the vehicle.

[0044] It should be understood that the "launch start mode" in step 201 is commonly found in high-performance vehicles and is a function designed to achieve the fastest acceleration. After the launch start mode is triggered, the vehicle can output the maximum torque at the moment of starting to achieve the best acceleration. In other words, during the launch start, the vehicle will show a dynamic of lifting its head, similar to the vehicle being launched.

[0045] Figure 3 It is a schematic diagram of a vehicle launch control method provided in an embodiment of the present application.

[0046] For example, Figure 3 As shown, taking a pure electric vehicle as an example, the difference between launch start and conventional start of a pure electric vehicle is described.

[0047] Specifically, during a regular start, the front and rear axle motors in a pure electric vehicle provide appropriate output torque based on the driver's acceleration command. During a regular start, the torque gradually increases with the depth of the accelerator pedal until it reaches a balance point, at which point the vehicle can accelerate smoothly without slipping. During a regular start, the output torque increase curve is relatively gentle to ensure the smoothness and controllability of the vehicle.

[0048] During a launch, the output torque of the front and rear axle motors increases very quickly, usually reaching a peak within a few seconds, and may then gradually decrease depending on the vehicle's dynamic response and the limitations of the battery management system. During a launch, the rising part of the output torque curve is steep to achieve rapid acceleration, while the falling part may be more gradual to protect the powertrain and maintain acceleration performance.

[0049] It should be understood that the launch mode usually relies on the high torque output of the engine or motor. In traditional fuel vehicles, the engine transmits torque to the wheels through the gearbox, thereby driving the vehicle to accelerate, while in new energy vehicles, the front and rear axle motors (front axle motor and rear axle motor) independently output torque and act together on the drive wheels of the new energy vehicle. The launch mode discussed in this application is mainly achieved through the front and rear axle motors.

[0050] It should also be understood that in the above step 201, the launch start process can be specifically divided into a slow acceleration process (acceleration start process) and a rapid acceleration process (launch start process). The acceleration start process is used to indicate the stage where the vehicle begins to accelerate after the launch start mode in the vehicle is triggered, and the acceleration of the vehicle does not reach the maximum acceleration during this stage. The launch start process is used to indicate that the acceleration of the vehicle is relatively large, which is sufficient to support the launch start of the vehicle. The "vehicle acceleration start" in step 201 can be regarded as the vehicle being in a slow acceleration process.

[0051] It should also be understood that in the above step 201, the "first change rate" is used to describe the change speed of the slip rate of the front wheel, and the "second change rate" is used to describe the change speed of the slip rate of the rear wheel. The first change rate and the second change rate are positive values.

[0052] In some embodiments, the vehicle is a racing car.

[0053] In some embodiments, the vehicle is a pure electric vehicle or a plug-in hybrid vehicle.

[0054] The determination process of “the first change rate of the slip ratio of the front wheels and the second change rate of the slip ratio of the rear wheels” in step 201 is discussed in detail as follows.

[0055] In some embodiments, a vehicle obtains a first change rate of the slip rate of a front wheel and a second change rate of the slip rate of a rear wheel in the vehicle, including: the vehicle obtains N actual speeds of the front wheel at N moments through a speed sensor of the front wheel, where N is a positive integer greater than 1; the vehicle determines N front wheel slip rates of the front wheel at N moments based on the N actual speeds of the front wheel and the corresponding N theoretical speeds; the vehicle determines the first change rate based on the N moments and the N front wheel slip rates; and the vehicle obtains the N actual speeds of the rear wheel at the N moments through a speed sensor of the rear wheel; the vehicle determines the N rear wheel slip rates of the rear wheel at N moments based on the N actual speeds of the rear wheel and the corresponding N theoretical speeds; the vehicle determines the second change rate based on the N moments and the N rear wheel slip rates.

[0056] In some embodiments, the vehicle determines N front wheel slip rates of the front wheel at N moments based on N actual rotational speeds of the front wheel and corresponding N theoretical rotational speeds, including: the vehicle determines the N front wheel slip rates of the front wheel at N moments based on the following formula (1);

[0057] (1)

[0058] in, for Any moment in time The front wheel slip rate of the front wheel, that is, the moment The slip rate of the front wheel, For any moment The actual speed of the front wheel, For any moment Theoretical speed of the front wheels.

[0059] It should be understood that, based on the above formula (1), the front wheel slip rate of the front wheel at the first moment is the first difference between the actual rotation speed of the front wheel at the first moment and the theoretical rotation speed of the front wheel at the first moment, and the slip rate is obtained by dividing the first difference by the theoretical rotation speed of the front wheel at the first moment.

[0060] In some embodiments, N is 2, the N front wheel slip rates include a first front wheel slip rate and a second front wheel slip rate, the N moments include a first moment and a second moment, and the vehicle determines the first change rate based on the N moments and the N front wheel slip rates, including: the vehicle determines the difference between the second front wheel slip rate and the first front wheel slip rate as the first change value; the vehicle determines the difference between the second moment and the first moment as the second change value; the vehicle determines the absolute value of the ratio of the first change value to the second change value as the first change rate.

[0061] It should be understood that when N is 2, the first front wheel slip rate is the second difference between the actual rotation speed of the front wheel at the first moment and the theoretical rotation speed of the front wheel at the first moment, and the second difference is divided by the theoretical rotation speed of the front wheel at the first moment to obtain the slip rate. The second front wheel slip rate is the third difference between the actual rotation speed of the front wheel at the second moment and the theoretical rotation speed of the front wheel at the second moment, and the third difference is divided by the theoretical rotation speed of the front wheel at the second moment to obtain the slip rate. The first moment corresponds to the first front wheel slip rate. The second moment corresponds to the second front wheel slip rate.

[0062] In some embodiments, the vehicle determines N rear wheel slip rates of the rear wheel at N moments based on the N actual rotation speeds of the rear wheel and the corresponding N theoretical rotation speeds, including: the vehicle determines the N rear wheel slip rates of the rear wheel at N moments based on the following formula (2);

[0063] (2)

[0064] in, for Any moment in time The rear wheel slip rate of the rear wheel, that is, the moment The slip rate of the rear wheel, For any moment The actual speed of the rear wheel, For any moment Theoretical rear wheel speed.

[0065] In some embodiments, N is 2, the N rear wheel slip rates include a first rear wheel slip rate and a second rear wheel slip rate, the N moments include a first moment and a second moment, and the vehicle determines the second change rate based on the N moments and the N rear wheel slip rates, including: the vehicle determines the difference between the second rear wheel slip rate and the first rear wheel slip rate as a third change value; the vehicle determines the difference between the second moment and the first moment as a fourth change value; the vehicle determines the absolute value of the ratio of the third change value to the fourth change value as the second change rate.

[0066] It should be understood that when N is 2, the first rear wheel slip rate is the fourth difference between the actual speed of the rear wheel at the first moment and the theoretical speed of the rear wheel at the first moment, and the fourth difference is divided by the theoretical speed of the rear wheel at the first moment to obtain the slip rate. The second rear wheel slip rate is the fifth difference between the actual speed of the rear wheel at the second moment and the theoretical speed of the rear wheel at the second moment, and the fifth difference is divided by the theoretical speed of the rear wheel at the second moment to obtain the slip rate. The first moment corresponds to the first rear wheel slip rate. The second moment corresponds to the second rear wheel slip rate.

[0067] The determination process of “the launch mode is triggered” in step 201 is discussed in detail as follows.

[0068] In some embodiments, the method 200 also includes at least one of the following: in response to the target object's click operation on a target button in the vehicle, the vehicle determines that the launch mode is triggered, and the target button is used to trigger the launch mode; in response to the target object's voice command to turn on the launch mode, the vehicle determines that the launch mode is triggered; in response to the target object's gesture operation to turn on the launch mode, the vehicle determines that the launch mode is triggered.

[0069] In some embodiments, the target object is a driver.

[0070] The following is a detailed discussion of the "process of controlling the vehicle to accelerate and start".

[0071] In one possible implementation, the method 200 also includes: in response to a trigger operation on the launch start mode, the vehicle adjusts the total braking force of multiple wheels in the vehicle to a braking force threshold, and controls the front axle motor and the rear axle motor to output their respective initial torques, where the initial torque is based on preset output torques corresponding to the front axle motor and the rear axle motor and an initial proportional relationship between the output torques of the front axle motor and the rear axle motor; the vehicle releases the total braking force within a preset time period, and based on a preset gradient, increases the initial torques corresponding to the front axle motor and the rear axle motor to corresponding target torques to control the vehicle to accelerate and start.

[0072] It should be understood that the "braking force threshold" in the above scheme is greater than the maximum value of the total driving force that can be output by the front and rear axle motors. In other words, in the above scheme, the vehicle adjusts the current total braking force to be greater than the current total driving force. The "adjusting the total braking force of multiple wheels in the vehicle to the braking force threshold" in the above scheme is to ensure that the vehicle is stationary. It should also be understood that the "initial torque corresponding to each of the front axle motor and the rear axle motor" in the above scheme refers to the relatively small torque that the front axle motor and the rear axle motor can output.

[0073] It should also be understood that the "releasing the total braking force within a preset time" in the above solution means gradually reducing or completely releasing the braking force on the vehicle within a specific time range so that the vehicle can accelerate smoothly or quickly. In order to achieve the purpose of vehicle launch, the preset time should be relatively short. It should also be understood that the "target torque" in the above solution refers to the relatively large torque that the front axle motor or the rear axle motor can output, which can be the maximum torque.

[0074] It should also be understood that the above scheme describes first controlling the vehicle to be stationary, and controlling the front axle motor and the rear axle motor to output smaller torques respectively; then quickly releasing the total braking force of the vehicle, and based on a preset gradient, increasing the output torques of the front axle motor and the rear axle motor respectively, so that the vehicle starts quickly.

[0075] In the above technical solution, before the vehicle accelerates and starts, the vehicle can respond to the triggering operation of the launch start mode and adjust the total braking force of multiple wheels in the vehicle to the braking force threshold to control the braking force of the vehicle to be greater than the driving force, and control the vehicle to remain stationary. At the same time, the vehicle controls the front axle motor and the rear axle motor to output their respective initial torques. This is for self-test and preheating, so that the vehicle can perform necessary inspections and preparations to ensure that it can work normally when the vehicle starts. Further, the total braking force is released within a preset time, and based on a preset gradient, the initial torque corresponding to each of the front axle motor and the rear axle motor is increased to the corresponding target torque. This is to immediately obtain the maximum traction by quickly increasing the output torque of the front and rear axle motors in a short time, so that the vehicle can quickly accelerate and start. In addition, releasing the total braking force within a preset time and increasing the output torque based on a preset gradient can avoid the risk of loss of control of the vehicle due to excessive power when starting, and can ensure driving safety.

[0076] In some embodiments, the preset duration is 3 seconds.

[0077] In some embodiments, the method for determining the preset gradient includes: the vehicle determines the preset gradient based on the adhesion coefficient of the road surface on which the vehicle is located and a third preset correspondence, and the third preset correspondence is used to describe the correspondence between the road surface adhesion coefficient and the gradient used to increase the output torque.

[0078] In one possible implementation, a method for determining an initial proportional relationship between the front axle motor and the rear axle motor in output torque includes: the vehicle detecting whether the longitudinal acceleration of the vehicle is lower than a preset acceleration; when the longitudinal acceleration is lower than the preset acceleration, the vehicle detecting whether the front wheels and the rear wheels of the vehicle are slipping at a uniform speed; when the front wheels and the rear wheels are slipping at a uniform speed, the vehicle obtains an initial proportional relationship between the front axle motor and the rear axle motor in output torque.

[0079] It should be understood that in the above scheme, "longitudinal acceleration" refers to the acceleration of the vehicle along its direction of travel, which is used to describe the speed change of the vehicle during forward or backward movement. The vehicle is currently in the process of accelerating and starting, and the longitudinal acceleration should be relatively small, and the longitudinal acceleration should be less than the preset acceleration. "Constant skidding of the front and rear wheels" means that during the acceleration of the vehicle, the front and rear wheels begin to slide relative to the ground because the driving force they receive exceeds the limit of the friction between the tires and the ground. During the sliding process, the vehicle maintains a constant speed to skid, but the displacement of the vehicle does not change.

[0080] It should also be understood that when the longitudinal acceleration of the vehicle is lower than the preset acceleration and the front and rear wheels of the vehicle are slipping at a constant speed, the vehicle can be deemed to be in a state of longitudinal force balance. In this state, the turning angle of the front wheels in the vehicle may be zero degrees, and the front axle motor and the rear axle motor are reversed. Among them, the turning angle of the front wheels refers to the offset angle when the front wheels turn to the left or right to the extreme position. The rotation direction of the motor shafts in the front axle motor and the rear axle motor can be achieved by changing the current direction of the front axle motor and the rear axle motor, so that the front axle motor and the rear axle motor are reversed.

[0081] In the above technical solution, at the moment of launch, the wheels in the vehicle need to overcome the maximum static friction in a stationary state with a larger driving force in order to accelerate as quickly as possible. When the front and rear wheels slip at a constant speed with a lower longitudinal acceleration, it indicates that the traction provided by the wheels is equal to the driving force, that is, the maximum available traction is reached. The torque distribution ratio relationship (initial ratio relationship) at this time can ensure that the vehicle outputs the maximum power (driving force) without losing traction. Therefore, when the longitudinal acceleration of the vehicle is low and the front and rear wheels slip at a constant speed, the initial ratio relationship between the output torque of the front axle motor and the rear axle motor is obtained, and it is used in the acceleration and starting process of the vehicle.

[0082] In some embodiments, the preset acceleration is 2 m / s 2 .

[0083] In one possible implementation, the method for determining the preset output torque corresponding to the front axle motor and the rear axle motor includes: when the longitudinal acceleration of the vehicle is lower than the preset acceleration and the front wheels and the rear wheels in the vehicle are slipping at a constant speed, the vehicle obtains the total output torque of the front axle motor and the rear axle motor, and the rotational speed of the front wheels and the rear wheels; the vehicle determines the adhesion coefficient of the road surface on which the vehicle is located based on the total output torque and the rotational speed, and a first preset correspondence, and the first preset correspondence is used to describe the correspondence between the total output torque of the front axle motor and the rear axle motor, and the rotational speed of the front wheels and the rear wheels when the front wheels and the rear wheels are slipping at a constant speed, and the road surface adhesion coefficient; the vehicle determines the preset output torque based on the adhesion coefficient and a second preset correspondence, and the second preset correspondence is used to describe the correspondence between the road surface adhesion coefficient and the preset output torque corresponding to the front axle motor and the rear axle motor.

[0084] It should be understood that in the above scheme, "the longitudinal acceleration of the vehicle is lower than the preset acceleration and the front and rear wheels of the vehicle are slipping at a constant speed" can be regarded as the vehicle being in a state of longitudinal force balance.

[0085] It should also be understood that the greater the road adhesion coefficient, the greater the preset output torque.

[0086] It should also be understood that when the vehicle first drives on the "road corresponding to the road surface on which the vehicle is located" in the above scheme, the vehicle needs to determine the adhesion coefficient of the road surface on which the vehicle is located and allocate the corresponding initial torques to the front axle motor and the rear axle motor according to the above scheme. In some embodiments, the vehicle displays a reminder message on the vehicle display screen in response to the triggering operation of the launch mode, and the reminder message is used to remind the target object whether to trigger the determination of the adhesion coefficient of the road surface on which the vehicle is located and the allocation of the corresponding initial torques to the front axle motor and the rear axle motor.

[0087] In the above technical solution, there is a corresponding relationship (first preset corresponding relationship) between the total output torque of the front axle motor and the rear axle motor, and the rotation speed of the front wheels and the rear wheels when the front wheels and the rear wheels slip at a constant speed, and the road adhesion coefficient. Therefore, the vehicle can accurately determine the adhesion coefficient of the road surface on which the vehicle is located based on the total output torque and the rotation speed, and the first preset corresponding relationship. There is a corresponding relationship (second preset corresponding relationship) between the road adhesion coefficient and the preset output torque corresponding to the front axle motor and the rear axle motor. Therefore, the vehicle can accurately determine the preset output torque corresponding to the front axle motor and the rear axle motor based on the adhesion coefficient and the second preset corresponding relationship.

[0088] In some embodiments, in response to a trigger operation on the launch mode, the vehicle adjusts the total braking force of multiple wheels in the vehicle to a braking force threshold, and controls the front axle motor and the rear axle motor to output respective corresponding initial torques, including: in response to a trigger operation on the launch mode, the vehicle obtains environmental information around the vehicle; when the environmental information indicates that the vehicle is on a closed road, the vehicle detects the remaining power of a power battery in the vehicle; when the remaining power is greater than a preset power, the vehicle detects the operating temperature of the power battery; when the operating temperature is within a preset temperature range, the vehicle adjusts the total braking force to the braking force threshold, and controls the front axle motor and the rear axle motor to output respective corresponding initial torques.

[0089] It should be understood that in the above scheme, when the environmental information around the vehicle indicates that the vehicle is not on a closed road, the vehicle detects whether there are obstacles around the vehicle. When there are obstacles around the vehicle, the vehicle does not perform the steps of adjusting the total braking force to the braking force threshold and controlling the front axle motor and the rear axle motor to output their respective initial torques. This is to avoid the vehicle colliding with the obstacle when accelerating and starting, and even causing serious traffic accidents. When there are no obstacles around the vehicle, the vehicle performs the step of detecting the remaining power of the power battery in the vehicle. When the operating temperature of the power battery is not within the preset temperature range, the vehicle does not perform the step of adjusting the total braking force to the braking force threshold and controlling the front axle motor and the rear axle motor to output their respective initial torques. This is to avoid the situation where the acceleration performance drops sharply and the launch start cannot be completed when the vehicle is still launched when the power is insufficient. At the same time, forcibly using the power battery at low power may cause the power battery to be over-discharged, which may damage the health of the power battery and shorten its service life.

[0090] In the above technical solution, when the vehicle is on a closed road and the remaining power of the power battery in the vehicle is relatively large, and the operating temperature of the power battery is within a preset temperature range, the vehicle controls the vehicle to accelerate and start. This is because launch control is a dangerous behavior, and drivers are usually advised to try it on closed roads. In addition, in order to ensure that there is enough energy to supply the front and rear axle motors to output maximum torque, the vehicle usually requires the remaining power of the power battery to be maintained at a high level. In this way, it is possible to avoid the situation where power output is limited due to insufficient power, resulting in the vehicle being unable to launch. Furthermore, extremely low temperatures or extremely high temperatures may limit the performance output of the vehicle. Therefore, in order to ensure that the vehicle can launch control stably, the vehicle requires the operating temperature of the power battery to be within a safe preset temperature range.

[0091] Figure 4 It is a schematic diagram of controlling the output of the front and rear axle motors to their respective initial torques provided in an embodiment of the present application.

[0092] For example, Figure 4 As shown, when the target object clicks the target button in the vehicle, the vehicle responds to the triggering operation of the launch mode and obtains the environmental information around the vehicle, and the target button is used to trigger the launch mode. When the environmental information indicates that the vehicle is in a closed road, the vehicle detects the remaining power of the power battery in the vehicle. When the remaining power is greater than the preset power, the vehicle detects the operating temperature of the power battery. When the operating temperature is within the preset temperature range, the vehicle adjusts the total braking force of multiple wheels to the braking force threshold, and controls the front axle motor and the rear axle motor to output the initial torques corresponding to each other. When the environmental information indicates that the vehicle is not in a closed road, the vehicle detects whether there are obstacles around the vehicle. When there are obstacles around the vehicle, the vehicle does not perform the steps of adjusting the total braking force to the braking force threshold and controlling the front axle motor and the rear axle motor to output the initial torques corresponding to each other. When there are no obstacles around the vehicle, the vehicle performs the step of detecting the remaining power of the power battery in the vehicle. When the operating temperature is not within the preset temperature range, the vehicle does not execute the steps of adjusting the total braking force to the braking force threshold and controlling the front axle motor and the rear axle motor to output their respective corresponding initial torques.

[0093] Step 202, when the first change rate is greater than the second change rate, the vehicle adjusts the initial proportional relationship between the front axle motor and the rear axle motor in the vehicle in terms of output torque based on the first change rate and the second change rate.

[0094] It should be understood that the "initial proportional relationship between the front axle motor and the rear axle motor in output torque" in the above step 202 refers to the initial torque distribution ratio between the front axle motor and the rear axle motor. The "initial proportional relationship" refers to the torque distribution ratio used by the vehicle during the acceleration process after the launch mode is triggered.

[0095] In one possible implementation, the vehicle in step 202 adjusts the initial proportional relationship between the front axle motor and the rear axle motor in the vehicle in terms of output torque based on the first change rate and the second change rate, including: the vehicle determines a first increase in the first change rate relative to the second change rate; the vehicle determines the product of the first increase and a first numerical value corresponding to the front axle motor in the initial proportional relationship as a second numerical value, and reduces the first numerical value by the second numerical value; the vehicle determines the product of the first increase and a third numerical value corresponding to the rear axle motor in the initial proportional relationship as a fourth numerical value, and increases the third numerical value by the fourth numerical value.

[0096] In the above technical solution, determining the first increase range of the first change rate relative to the second change rate can quantify how much faster the change speed of the slip rate of the front wheel is compared to the change speed of the slip rate of the rear wheel. Normally, when the change speed of the slip rate of the front wheel is greater than the change speed of the slip rate of the rear wheel, the vehicle reduces the first value corresponding to the front axle motor in the initial proportional relationship, and increases the third value corresponding to the rear axle motor in the initial proportional relationship. The rate of change of the slip rate of the front wheel and the rate of change of the slip rate of the rear wheel will affect the output torque of the front and rear axle motors. The slip rate can reflect the adhesion condition between the tire and the ground, and the torque output of the front and rear axle motors can be adjusted based on the adhesion condition of the tire. Therefore, in this method, the vehicle determines the product of the first increase amplitude and the first numerical value corresponding to the front axle motor in the initial proportional relationship as the second numerical value, and reduces the first numerical value by the second numerical value to accurately obtain the fifth numerical value corresponding to the front axle motor in the adjusted proportional relationship; determines the product of the first increase amplitude and the third numerical value corresponding to the rear axle motor in the initial proportional relationship as the fourth numerical value, and increases the third numerical value by the fourth numerical value to accurately obtain the sixth numerical value corresponding to the rear axle motor in the adjusted proportional relationship.

[0097] In some embodiments, the vehicle determines a first increase amplitude of the first change rate relative to the second change rate, including: the vehicle determines the first increase amplitude based on the following formula (3);

[0098] (3)

[0099] in, is the first increase, is the first rate of change, is the second change rate.

[0100] For example, the initial ratio is the first value A / the third value B, and the first increase is Taking the example, the process of adjusting the initial proportional relationship between the front axle motor and the rear axle motor in output torque to obtain the adjusted proportional relationship is described.

[0101] Specifically, the vehicle connects A with The product between is determined as the second value C, and A is reduced by C; the vehicle reduces B and The product between them is determined as the fourth value D, and B is reduced by D, so that the adjusted proportional relationship is (first value-second value) / (third value-fourth value), that is, (AC) / (BD).

[0102] In step 203 , the vehicle adjusts the current output torques of the front axle motor and the rear axle motor respectively based on the adjusted proportional relationship to perform launch control on the vehicle.

[0103] It should be understood that in the above step 203, the torque outputted by the front axle motor and the rear axle motor is controlled, and the front wheels and the rear wheels are accelerated by the driving force, so as to perform launch control on the vehicle. The driving force can be obtained by calculating the torque.

[0104] In one possible implementation, step 203 includes: the vehicle determines the sum of the current output torque of the front axle motor and the current output torque of the rear axle motor as the total output torque; the vehicle allocates a first output torque to the front axle motor and a second output torque to the rear axle motor from the total output torque based on the adjusted proportional relationship and the total output torque; the vehicle adjusts the current output torque of the front axle motor to the first output torque, and adjusts the current output torque of the rear axle motor to the second output torque.

[0105] It should be understood that the above scheme of "based on the adjusted proportional relationship and the total output torque, allocating the first output torque to the front axle motor from the total output torque, and allocating the second output torque to the rear axle motor" refers to the specific process for determining the adjusted output torque of the front axle motor and the rear axle motor, rather than adjusting the current output torque.

[0106] In the above technical solution, the maximum torque capacity (total output torque) output by the front and rear axle motors is determined. After obtaining the adjusted proportional relationship, the vehicle can accurately allocate output torque (first output torque) to the front axle motor and allocate output torque (second output torque) to the rear axle motor based on the adjusted proportional relationship and the total output torque. Therefore, the vehicle adjusts the current output torque of the front axle motor to the first output torque, and adjusts the current output torque of the rear axle motor to the second output torque. In this way, the change speed of the slip rate of the front and rear wheels can be close, so that the vehicle can effectively convert the power generated by the engine into forward traction, which helps to control the vehicle to perform a standard launch start.

[0107] The following is a detailed discussion of “a process of controlling the vehicle when the first change rate of the slip ratio of the front wheels is smaller than the second change rate of the slip ratio of the rear wheels”.

[0108] In one possible implementation, the method 200 also includes: when the first change rate is less than the second change rate, the vehicle determines the flatness index of the road surface on which the vehicle is located; when the flatness index is higher than a preset index, the vehicle adjusts the tire pressure of the rear wheels of the vehicle based on the flatness index and the preset index; when the flatness index is lower than the preset index, the vehicle reduces the opening of the accelerator pedal in the vehicle based on the difference between the second change rate and the first change rate.

[0109] It should be understood that the "flatness index of the road surface on which the vehicle is located" in the above scheme refers to the vertical deviation of the surface of the road surface on which the vehicle is located (road surface) relative to the ideal plane, that is, the deviation value of the longitudinal concavity and convexity of the road surface. The flatness index mainly reflects the flatness of the road surface longitudinal section profile curve. When the road surface longitudinal section profile curve is relatively smooth, it means that the road surface is relatively flat or the flatness index is small.

[0110] In the above technical solution, when the rate of change of the slip rate of the front wheel (first rate of change) is less than the rate of change of the slip rate of the rear wheel (second rate of change), the rapid slip of the rear wheel may cause the rear of the vehicle to lose traction, while the front wheel still tries to maintain grip, which will cause the center of gravity of the vehicle to move backward and may cause the rear of the vehicle to lift. Therefore, the vehicle needs the rear wheel to maintain grip. However, there are many factors that affect the grip of the rear wheel. When the first rate of change is less than the second rate of change, the method determines the flatness index of the road surface on which the vehicle is located. When the flatness index is higher than the preset index, the tire pressure of the rear wheel in the vehicle is adjusted based on the flatness index and the preset index, so that the contact area between the rear wheel tire and the ground can be increased, thereby improving traction. This can make the vehicle more stable when accelerating. When the flatness index is lower than the preset index, the vehicle reduces the opening of the accelerator pedal in the vehicle, which can help the engine reduce the output torque, thereby reducing the slip rate of the rear wheel. This helps to improve the grip of the rear wheel and improve the acceleration efficiency and handling stability of the vehicle.

[0111] In some embodiments, a vehicle determines the flatness index of a road surface on which the vehicle is located, including: the vehicle collects original elevation values ​​of each cross section along the road width direction through a line scanning three-dimensional measuring device in the vehicle, and obtains a first elevation value corresponding to the original elevation value; the vehicle corrects the first elevation value of each cross section based on the posture parameters corresponding to the line scanning three-dimensional measuring device, the calibrated working distance, the working distance of the line scanning three-dimensional measuring device in the elevation direction corresponding to each cross section collected by the line scanning three-dimensional measuring device, and the preset number of measuring points of each cross section, to obtain a second elevation value of each cross section; the vehicle determines third elevation values ​​of each longitudinal section perpendicular to each cross section based on the second elevation values ​​of each cross section; the vehicle determines the flatness index based on the relationship data corresponding to the third elevation value and the international flatness index.

[0112] It should be understood that in the above scheme, "line scanning three-dimensional measurement device" refers to a device that uses laser or other light sources to project lines onto the surface of an object and obtains geometric information of the object surface by receiving reflected or transmitted light. The line scanning three-dimensional measurement device includes a line scanning three-dimensional camera, a posture sensor and a laser. "Road width direction" refers to the direction perpendicular to the center line of the road, and the road width direction is opposite to the direction in which the center line of the road extends. "Cross section" refers to the vertical section perpendicular to the driving direction at each point on the center line of the road where the vehicle is traveling.

[0113] It should also be understood that in the above scheme, the "original elevation value of the cross section" refers to the height value of each point on the cross section relative to the reference surface (such as the geoid). The original elevation data of the cross section directly collected by the line scanning three-dimensional camera is the value in the image coordinate system, that is, the image coordinate value, and the elevation value required for the subsequent calculation of the international flatness index is the value in the object coordinate system, that is, the object coordinate data. Therefore, it is necessary to convert the original elevation value in the image coordinate system into the elevation value in the object coordinate system, that is, the first elevation value. The "calibrated working distance corresponding to the line scanning three-dimensional measuring device" refers to the distance between the line scanning three-dimensional measuring device and the surface of the object. The "relationship data corresponding to the international flatness index" can be regarded as the calculation formula of the international flatness index.

[0114] In some embodiments, the number of measuring points is N, the third elevation value includes N elevation difference values, any elevation difference value corresponds to a horizontal distance, and the vehicle determines the flatness index based on the relationship data corresponding to the third elevation value and the international flatness index, including: the vehicle determines N adjusted slopes based on the ratio between the N elevation difference values ​​and the corresponding horizontal distances; the vehicle determines the flatness index based on the N adjusted slopes and the relationship data.

[0115] It should be understood that in the above scheme, the "elevation difference value" refers to the difference between any two adjacent elevation values ​​among the multiple elevation values. Any elevation value corresponds to a measurement point. The "horizontal distance corresponding to the elevation difference value" refers to the straight-line distance between the two measurement points measured along the horizontal plane.

[0116] In some embodiments, the vehicle determines the flatness index based on the N adjusted slopes and the relationship data, including: the vehicle determines the flatness index based on the following formula (4);

[0117] (4)

[0118] in, is the flatness index, For the Adjust the slope of each measuring point.

[0119] In some embodiments, the vehicle adjusts the tire pressure of the rear wheels of the vehicle based on the flatness index and the preset index, including: the vehicle determines a second increase in the flatness index relative to the preset index; the vehicle determines the product of the second increase and the tire pressure as a tire pressure adjustment value; and the vehicle reduces the tire pressure by the tire pressure adjustment value.

[0120] It should be understood that after the launch mode is triggered and the slip rate of the rear wheels changes slowly, the rear of the vehicle loses traction, which may cause the rear of the vehicle to lift. If the surface of the road on which the vehicle is driving is uneven (the flatness index is relatively small), the vehicle can reduce the tire pressure to increase the tire contact area, thereby improving traction, so that the vehicle can launch.

[0121] In some embodiments, the vehicle reduces the current opening of the accelerator pedal in the vehicle based on the difference between the second change rate and the first change rate, including: the vehicle determines a reference opening amount for reducing the current opening based on the difference between the second change rate and the first change rate and a fourth preset corresponding relationship; the vehicle determines a third increase amplitude of the second change rate relative to the first change rate; the vehicle determines the product of the reference opening amount and the third increase amplitude as the opening reduction amount; and the vehicle reduces the current opening by the opening reduction amount.

[0122] In some embodiments, after reducing the current opening of the accelerator pedal in the vehicle, the method 200 also includes: the vehicle determines the product of the current braking force of the rear wheel and the third increase amplitude as the adjustment amount; the vehicle determines the sum of the current braking force and the adjustment amount as the target braking force; the vehicle adjusts the current braking force of the rear wheel to the target braking force.

[0123] Figure 5 It is a structural schematic diagram of a device for controlling vehicle starting provided in an embodiment of the present application.

[0124] For example, Figure 5 As shown, the device 500 includes:

[0125] The acquisition module 501 is used to acquire a first change rate of the slip rate of the front wheels and a second change rate of the slip rate of the rear wheels in the vehicle when a launch mode in the vehicle is triggered and the vehicle accelerates to start;

[0126] Adjustment module 502: used for:

[0127] When the first change rate is greater than the second change rate, adjusting the initial proportional relationship between the front axle motor and the rear axle motor in the vehicle in terms of output torque based on the first change rate and the second change rate;

[0128] Based on the adjusted proportional relationship, the current output torques corresponding to the front axle motor and the rear axle motor are adjusted respectively to perform launch control on the vehicle.

[0129] Optionally, the device 500 also includes: a determination module, used to determine a first increase range of the first change rate relative to the second change rate; the adjustment module 502, specifically used to: determine the product of the first increase range and the first numerical value corresponding to the front axle motor in the initial proportional relationship as the second numerical value, and reduce the first numerical value by the second numerical value; determine the product of the first increase range and the third numerical value corresponding to the rear axle motor in the initial proportional relationship as a fourth numerical value, and increase the third numerical value by the fourth numerical value.

[0130] Optionally, the determination module is specifically used to: determine the sum of the current output torque of the front axle motor and the current output torque of the rear axle motor as the total output torque; based on the adjusted proportional relationship and the total output torque, allocate a first output torque to the front axle motor from the total output torque, and allocate a second output torque to the rear axle motor; the adjustment module 502 is also specifically used to adjust the current output torque of the front axle motor to the first output torque, and adjust the current output torque of the rear axle motor to the second output torque.

[0131] Optionally, the adjustment module 502 is also used to: in response to a triggering operation on the launch start mode, adjust the total braking force of multiple wheels in the vehicle to a braking force threshold, and control the front axle motor and the rear axle motor to output their respective initial torques, where the initial torque is based on preset output torques corresponding to the front axle motor and the rear axle motor and an initial proportional relationship between the output torques of the front axle motor and the rear axle motor; release the total braking force within a preset time period, and based on a preset gradient, increase the initial torques corresponding to the front axle motor and the rear axle motor to corresponding target torques to control the vehicle to accelerate and start.

[0132] Optionally, the device 500 also includes: a detection module, used to: detect whether the longitudinal acceleration of the vehicle is lower than a preset acceleration; when the longitudinal acceleration is lower than the preset acceleration, detect whether the front wheels and the rear wheels in the vehicle are slipping at a constant speed; the acquisition module 501 is specifically used to obtain the initial proportional relationship between the front axle motor and the rear axle motor in the output torque when the front wheels and the rear wheels are slipping at a constant speed.

[0133] Optionally, the acquisition module 501 is further specifically used to acquire the total output torque of the front axle motor and the rear axle motor, and the rotational speed of the front wheels and the rear wheels when the longitudinal acceleration of the vehicle is lower than a preset acceleration and the front wheels and the rear wheels in the vehicle are slipping at a constant speed; the determination module is further specifically used to: determine the adhesion coefficient of the road surface on which the vehicle is located based on the total output torque and the rotational speed, and a first preset correspondence relationship, the first preset correspondence relationship being used to describe the correspondence between the total output torque of the front axle motor and the rear axle motor, and the rotational speed of the front wheels and the rear wheels when the front wheels and the rear wheels are slipping at a constant speed, and the road adhesion coefficient; determine the preset output torque based on the adhesion coefficient and a second preset correspondence relationship, the second preset correspondence relationship being used to describe the correspondence between the road adhesion coefficient and the preset output torque corresponding to the front axle motor and the rear axle motor.

[0134] Optionally, the determination module is further used to determine the flatness index of the road surface on which the vehicle is located when the first change rate is less than the second change rate; the adjustment module 502 is further used to: when the flatness index is higher than a preset index, adjust the tire pressure of the rear wheels of the vehicle based on the flatness index and the preset index; when the flatness index is lower than the preset index, reduce the opening of the accelerator pedal in the vehicle based on the difference between the second change rate and the first change rate.

[0135] Figure 6 It is a structural schematic diagram of a vehicle provided in an embodiment of the present application.

[0136] For example, Figure 6 As shown, the vehicle 600 includes: a memory 601 and a processor 602, wherein the memory 601 stores an executable program code 603, and the processor 602 is used to call and execute the executable program code 603 to perform a method for controlling the vehicle to start.

[0137] In addition, an embodiment of the present application also protects a device, which may include a memory and a processor, wherein the memory stores an executable program code, and the processor is used to call and execute the executable program code to execute a method for controlling vehicle starting provided in an embodiment of the present application.

[0138] In this embodiment, the functional modules of the device can be divided according to the above method example. For example, each functional module can be corresponded, or two or more functions can be integrated into one processing module. The above integrated module can be implemented in the form of hardware. It should be noted that the division of modules in this embodiment is schematic and is only a logical function division. There may be other division methods in actual implementation.

[0139] In the case of dividing each functional module according to each function, the device may also include an acquisition module, an adjustment module, a detection module, a determination module, etc. It should be noted that all relevant contents involved in the above method embodiment can be referred to the functional description of the corresponding functional module, which will not be repeated here.

[0140] It should be understood that the device provided in this embodiment is used to execute the above-mentioned method for controlling the start of a vehicle, and thus can achieve the same effect as the above-mentioned implementation method.

[0141] In the case of an integrated unit, the device may include a processing module and a storage module. When the device is applied to a vehicle, the processing module may be used to control and manage the actions of the vehicle. The storage module may be used to support the vehicle in executing related executable program codes, etc.

[0142] The processing module may be a processor or a controller, which may implement or execute various exemplary logic blocks, modules and circuits shown in combination with the contents disclosed in this application. The processor may also be a combination that implements computing functions, such as a combination of one or more microprocessors, a combination of digital signal processing (DSP) and a microprocessor, etc. The storage module may be a memory.

[0143] In addition, the device provided in the embodiments of the present application may specifically be a chip, a component or a module, and the chip may include a connected processor and a memory; wherein the memory is used to store instructions, and when the processor calls and executes the instructions, the chip can execute a method for controlling vehicle starting provided in the above embodiment.

[0144] This embodiment also provides a computer-readable storage medium, in which executable program code is stored. When the executable program code is run on a computer, the computer executes the above-mentioned related method steps to implement a method for controlling vehicle starting provided in the above embodiment.

[0145] This embodiment further provides a computer program product. When the computer program product is run on a computer, the computer is caused to execute the above-mentioned related steps to implement a method for controlling vehicle starting provided in the above embodiment.

[0146] Among them, the device, computer-readable storage medium, computer program product or chip provided in this embodiment is used to execute the corresponding method provided above. Therefore, the beneficial effects that can be achieved can refer to the beneficial effects in the corresponding method provided above, and will not be repeated here.

[0147] Through the description of the above implementation methods, technical personnel in the relevant field can understand that for the convenience and simplicity of description, only the division of the above-mentioned functional modules is used as an example. In actual applications, the above-mentioned functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above.

[0148] In the embodiments provided in the present application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic, for example, the division of modules or units is only a logical function division, and there may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another device, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0149] The above contents are only specific implementation methods of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A method for controlling vehicle starting, characterized in that: The method comprises: When a launch mode in a vehicle is triggered and the vehicle is accelerated and started, obtaining a first change rate of a slip ratio of a front wheel and a second change rate of a slip ratio of a rear wheel in the vehicle; When the first change rate is greater than the second change rate, adjusting the initial proportional relationship between the output torque of the front axle motor and the rear axle motor in the vehicle based on the first change rate and the second change rate; Adjusting the current output torques of the front axle motor and the rear axle motor based on the adjusted proportional relationship to perform launch control on the vehicle; The adjusting of the current output torques corresponding to the front axle motor and the rear axle motor based on the adjusted proportional relationship includes: Determine the sum of the current output torque of the front axle motor and the current output torque of the rear axle motor as the total output torque; Based on the adjusted proportional relationship and the total output torque, allocating a first output torque to the front axle motor and allocating a second output torque to the rear axle motor from the total output torque; The current output torque of the front axle motor is adjusted to the first output torque, and the current output torque of the rear axle motor is adjusted to the second output torque.

2. The method according to claim 1, characterized in that The adjusting, based on the first change rate and the second change rate, an initial proportional relationship between the output torques of the front axle motor and the rear axle motor includes: determining a first increase of the first rate of change relative to the second rate of change; Determine a second value by multiplying the first increase amplitude by a first value corresponding to the front axle motor in the initial proportional relationship, and reduce the first value by the second value; The product of the first increase amplitude and the third value corresponding to the rear axle motor in the initial proportional relationship is determined as a fourth value, and the third value is increased by the fourth value.

3. The method according to claim 1, characterized in that The method further comprises: In response to the triggering operation of the launch mode, the total braking force of the plurality of wheels of the vehicle is adjusted to a braking force threshold, and the front axle motor and the rear axle motor are controlled to output respective initial torques, wherein the initial torques are obtained based on the preset output torques corresponding to the front axle motor and the rear axle motor and the initial proportional relationship between the output torques of the front axle motor and the rear axle motor; The total braking force is released within a preset time period, and based on a preset gradient, the initial torques corresponding to the front axle motor and the rear axle motor are increased to corresponding target torques to control the vehicle to accelerate and start.

4. The method according to claim 3, characterized in that: The method for determining the initial proportional relationship between the front axle motor and the rear axle motor in output torque includes: Detecting whether the longitudinal acceleration of the vehicle is lower than a preset acceleration; When the longitudinal acceleration is lower than the preset acceleration, detecting whether the front wheels and the rear wheels in the vehicle are slipping at a constant speed; When the front wheels and the rear wheels slip at a constant speed, an initial proportional relationship between the output torques of the front axle motor and the rear axle motor is obtained.

5. The method according to claim 3, characterized in that: The method for determining the preset output torque corresponding to the front axle motor and the rear axle motor includes: When the longitudinal acceleration of the vehicle is lower than a preset acceleration and the front wheels and the rear wheels in the vehicle are slipping at a constant speed, obtaining the total output torque of the front axle motor and the rear axle motor, and the rotation speeds of the front wheels and the rear wheels; Determining an adhesion coefficient of a road surface on which the vehicle is located based on the total output torque and the rotational speed, and a first preset corresponding relationship, wherein the first preset corresponding relationship is used to describe a corresponding relationship between a total output torque of a front axle motor and a rear axle motor, and the rotational speeds of the front wheels and the rear wheels when the front wheels and the rear wheels slip at a constant speed, and the road surface adhesion coefficient; The preset output torque is determined based on the adhesion coefficient and a second preset corresponding relationship, wherein the second preset corresponding relationship is used to describe the corresponding relationship between the road adhesion coefficient and the preset output torque corresponding to the front axle motor and the rear axle motor.

6. The method according to claim 1, characterized in that The method further comprises: When the first rate of change is less than the second rate of change, determining a roughness index of the road surface on which the vehicle is located; When the flatness index is higher than a preset index, adjusting the tire pressure of the rear wheels of the vehicle based on the flatness index and the preset index; When the flatness index is lower than the preset index, the opening of the accelerator pedal in the vehicle is reduced based on the difference between the second change rate and the first change rate.

7. A device for controlling vehicle starting, characterized in that: The device comprises: an acquisition module, configured to acquire a first change rate of a slip ratio of a front wheel and a second change rate of a slip ratio of a rear wheel in the vehicle when a launch mode in the vehicle is triggered and the vehicle is accelerated to start; Adjustment modules for: When the first change rate is greater than the second change rate, adjusting the initial proportional relationship between the output torque of the front axle motor and the rear axle motor in the vehicle based on the first change rate and the second change rate; Adjusting the current output torques of the front axle motor and the rear axle motor based on the adjusted proportional relationship to perform launch control on the vehicle; The adjustment module is specifically used for: Determine the sum of the current output torque of the front axle motor and the current output torque of the rear axle motor as the total output torque; Based on the adjusted proportional relationship and the total output torque, allocating a first output torque to the front axle motor and allocating a second output torque to the rear axle motor from the total output torque; The current output torque of the front axle motor is adjusted to the first output torque, and the current output torque of the rear axle motor is adjusted to the second output torque.

8. A vehicle, characterized in that: The vehicle comprises: A memory for storing executable program codes; A processor, configured to call and run the executable program code from the memory, so that the vehicle executes the method according to any one of claims 1 to 6.

9. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores an executable program code, and when the executable program code is executed, the method according to any one of claims 1 to 6 is implemented.

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