Vehicle starting control method and device and vehicle

Abstract

The invention relates to the technical field of vehicles, in particular to a vehicle starting control method and device and a vehicle. The method comprises the steps that the actual wheel speed and the target wheel speed of a driving wheel on each side in the vehicle starting process are obtained; the wheel speed difference value between the actual wheel speed of the driving wheel on each side and the target wheel speed is calculated, and if the wheel speed difference value of the driving wheel on any side is larger than an activation threshold value, a driving anti-skid control system of the vehicle is activated; and the target driving torque of the vehicle is obtained, and the anti-skid control system is controlled and driven to dynamically output the target braking torque according to the target driving torque so as to assist vehicle starting. Therefore, the problems that in the prior art, driving anti-skid control is large in noise, high in energy consumption, poor in driving comfort and the like are solved.

Description

Technical Field

[0001] The present application relates to the field of vehicle technology, and in particular to a vehicle starting control method, device and vehicle. Background Art

[0002] When a car is started on a rain-soaked and muddy asphalt road or on a snowy road, the car may skid or even turn. If the left and right wheels are on different surfaces, such as one wheel on a snowy road and the other wheel on an exposed asphalt road, the car will have difficulty starting and may even lose control of the direction. When driving at high speed on a curve, the car may slide off the roadside or run into the opposite lane. Figure 1 shown.

[0003] TC (Traction Control System) is developed to prevent these dangerous situations. According to the tire adhesion characteristic curve, when the wheel slip rate is between 10% and 30%, the tire longitudinal adhesion coefficient is near the peak value, and the road surface can provide the wheel with a large longitudinal force and driving force. At the same time, the vehicle's lateral adhesion coefficient has not entered the area of ​​rapid decline, and the vehicle has a certain lateral force, so the slip rate is an ideal value in this range.

[0004] The control target of TC is to control the vehicle's slip rate within 12% to 20%. For split roads, the current drive anti-skid control system will apply braking force to the low-adhesion side, simulating the differential lock function to transfer torque to the high-adhesion side, so as to achieve the purpose of vehicle starting drive. The drive anti-skid control on split roads involves driving force control and braking force control and the coordination between the two. On split roads, due to the deviation of the longitudinal force on the high-adhesion side and the low-adhesion side, the whole vehicle will produce a certain yaw effect around the z direction. At this time, the driver needs to correct the control through the steering wheel to prevent the vehicle from running off.

[0005] However, the TC drive anti-skid control of the prior art has the following problems: when the vehicle starts on a road with two sides, as long as there is a difference in adhesion between the left and right sides, the TC will request the braking system to apply braking force to the side with lower adhesion. Frequent intervention of braking force will affect driving comfort, and the intervention of braking is accompanied by loud noise (mechanical friction caused by valve pump actuation and caliper clamping force). Frequent intervention of braking will also increase energy consumption and affect the cruising range of electric vehicles. Summary of the invention

[0006] The present application provides a vehicle starting control method, device and vehicle to solve the problems of high noise, high energy consumption and poor driving comfort in the prior art of drive anti-skid control.

[0007] The first aspect of the present application provides a vehicle starting control method, in which the vehicle is a vehicle, comprising the following steps: obtaining the actual wheel speed and target wheel speed of the driving wheels on each side during the vehicle starting process; calculating the wheel speed difference between the actual wheel speed and the target wheel speed of the driving wheels on each side, and if the wheel speed difference of the driving wheels on either side is greater than an activation threshold, activating the vehicle's drive anti-skid control system; obtaining the vehicle's target driving torque, and controlling the drive anti-skid control system to dynamically output a target braking torque according to the target driving torque to assist the vehicle starting.

[0008] Optionally, obtaining the target driving torque of the vehicle includes: obtaining the slope of the road on which the vehicle is currently located, road adhesion and wheel slip rate; and calculating the target driving torque of the vehicle according to the slope, road adhesion and slip rate.

[0009] Optionally, controlling the drive anti-skid control system to dynamically output a target braking torque according to the target drive torque includes: determining the maximum drive torque of the vehicle according to the slope and road adhesion; and controlling the drive anti-skid control system to dynamically output the target braking torque according to the target drive torque and the maximum drive torque.

[0010] Optionally, the drive anti-skid control system is controlled to dynamically output the target braking torque according to the target driving torque and the maximum driving torque, including: if the target driving torque is less than or equal to the maximum driving torque, the braking force enabling and calculation module of the drive anti-skid control system is allowed to be disenabled; if the target driving torque is greater than the maximum driving torque, the braking force enabling and calculation module of the drive anti-skid control system is allowed to be enabled to output the target braking torque, or, the braking force enabling and calculation module of the drive anti-skid control system is controlled to output the target braking torque after being downgraded.

[0011] Optionally, after allowing the braking force enabling and calculation module of the drive anti-skid control system to output the target braking torque, it also includes: obtaining the actual driving torque of each wheel of the vehicle; calculating the first vehicle yaw torque according to the actual driving torque of each wheel, and obtaining the first yaw angular velocity detected by the yaw sensor of the vehicle; determining whether the vehicle meets the target stability requirement based on the first vehicle yaw torque and the first yaw angle; if the vehicle does not meet the target stability requirement, allowing the yaw compensation force and enabling module of the drive anti-skid control system to be enabled, otherwise not allowing the yaw compensation force and enabling module of the drive anti-skid control system to be enabled, wherein the yaw compensation force and enabling module is used to control the non-driven wheels to turn according to the first target turning angle.

[0012] Optionally, after allowing the braking force enabling and calculation module of the driving anti-skid control system to output the target braking torque, it also includes: obtaining the actual braking torque and the actual driving torque of each wheel of the vehicle; calculating the second vehicle yaw moment according to the actual braking torque and the actual driving torque of each wheel, and obtaining the second yaw angular velocity detected by the yaw sensor of the vehicle; determining whether the vehicle meets the target stability requirement based on the second vehicle yaw moment and the second yaw angle; if the vehicle does not meet the target stability requirement, allowing the yaw compensation force and enabling module of the driving anti-skid control system to be enabled, otherwise not allowing the yaw compensation force and enabling module of the driving anti-skid control system to be enabled, wherein the yaw compensation force and enabling module is used to control the non-driven wheels to turn according to the second target turning angle.

[0013] Optionally, the target stability requirement is that the vehicle's whole vehicle yaw moment is less than a yaw moment threshold and the yaw angular velocity is less than a yaw angular velocity threshold, and the target turning angle is determined based on the whole vehicle yaw moment and is used to compensate for the whole vehicle yaw moment generated when the vehicle starts.

[0014] Optionally, enabling the braking force enabling and calculating module of the driving anti-skid control system to output the target braking torque includes: determining the target braking torque according to the current operating condition of the vehicle; controlling the braking force enabling and calculating module of the driving anti-skid control system to output the target braking torque after being downgraded includes: determining the target braking torque according to the current operating condition and braking level of the vehicle.

[0015] The second aspect of the present application provides a vehicle starting control device, including: an acquisition module, used to obtain the actual wheel speed and target wheel speed of the driving wheels on each side during the vehicle starting process; an activation module, used to calculate the wheel speed difference between the actual wheel speed and the target wheel speed of the driving wheels on each side, if the wheel speed difference of the driving wheels on either side is greater than the activation threshold, the vehicle's drive anti-skid control system is activated; a control module, used to obtain the vehicle's target driving torque, and control the drive anti-skid control system to dynamically output a target braking torque according to the target driving torque to assist the vehicle starting.

[0016] Optionally, the acquisition module is further used to: acquire the slope of the road on which the vehicle is currently located, the road adhesion and the slip rate of the vehicle; and calculate the target driving torque of the vehicle according to the slope, the road adhesion and the slip rate.

[0017] Optionally, the control module is further used to: determine the maximum driving torque of the vehicle according to the slope and road adhesion; and control the driving anti-skid control system to dynamically output the target braking torque according to the target driving torque and the maximum driving torque.

[0018] Optionally, the control module is further used to: if the target driving torque is less than or equal to the maximum driving torque, allow the braking force enabling and calculation module of the driving anti-skid control system to be disenabled; if the target driving torque is greater than the maximum driving torque, allow the braking force enabling and calculation module of the driving anti-skid control system to be enabled to output the target braking torque, or control the braking force enabling and calculation module of the driving anti-skid control system to output the target braking torque after being downgraded.

[0019] Optionally, it also includes: a first determination module, used to obtain the actual driving torque of each wheel of the vehicle after allowing the braking force enabling and calculation module of the driving anti-skid control system to output the target braking torque; calculate the first vehicle yaw torque according to the actual driving torque of each wheel, and obtain the first yaw angular velocity detected by the yaw sensor of the vehicle; determine whether the vehicle meets the target stability requirement based on the first vehicle yaw torque and the first yaw angle; if the vehicle does not meet the target stability requirement, allow the yaw compensation force and enabling module of the driving anti-skid control system to be enabled, otherwise it is not allowed to enable the yaw compensation force and enabling module of the driving anti-skid control system, wherein the yaw compensation force and enabling module is used to control the non-driven wheels to turn according to the first target turning angle.

[0020] Optionally, it also includes: a second determination module, which is used to obtain the actual braking torque and actual driving torque of each wheel of the vehicle after allowing the braking force enabling and calculation module of the driving anti-skid control system to output the target braking torque; calculate the second vehicle yaw moment according to the actual braking torque and the actual driving torque of each wheel, and obtain the second yaw angular velocity detected by the yaw sensor of the vehicle; determine whether the vehicle meets the target stability requirement based on the second vehicle yaw moment and the second yaw angle; if the vehicle does not meet the target stability requirement, it is allowed to enable the yaw compensation force and enabling module of the driving anti-skid control system, otherwise it is not allowed to enable the yaw compensation force and enabling module of the driving anti-skid control system, wherein the yaw compensation force and enabling module is used to control the non-driven wheels to turn according to the second target turning angle.

[0021] Optionally, the target stability requirement is that the vehicle's whole vehicle yaw moment is less than a yaw moment threshold and the yaw angular velocity is less than a yaw angular velocity threshold, and the target turning angle is determined based on the whole vehicle yaw moment and is used to compensate for the whole vehicle yaw moment generated when the vehicle starts.

[0022] Optionally, the control module is further used to: determine the target braking torque according to the current operating condition of the vehicle; control the braking force enable of the drive anti-skid control system and output the target braking torque after the calculation module is downgraded, including: determining the target braking torque according to the current operating condition and braking level of the vehicle.

[0023] A third aspect of the present application provides a vehicle, comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement a vehicle starting control method as described in the above embodiment.

[0024] Therefore, this application includes the following beneficial effects:

[0025] The embodiment of the present application can activate the vehicle's drive anti-skid system when the difference between the actual wheel speed of the driving wheel on any side and the target wheel speed is greater than the activation threshold, avoiding frequent intervention of braking force to reduce noise and energy consumption, thereby increasing the vehicle's cruising range, and dynamically outputting the target braking torque according to the vehicle's target driving torque to assist the vehicle in starting, ensure a smooth start of the vehicle, and improve driving safety and comfort. Thus, the technical problems of high noise, high energy consumption, and poor driving comfort in the prior art of drive anti-skid control are solved.

[0026] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0028] Figure 1 A schematic diagram of a vehicle skidding;

[0029] Figure 2 It is a schematic diagram of the driving torque control variables of the driving anti-skid control system during stationary acceleration on a low-adhesion road surface in the prior art;

[0030] Figure 3 It is a schematic diagram of the braking torque control variables of the driving anti-skid control system when starting and accelerating on a separated road in the prior art;

[0031] Figure 4 A flowchart of a vehicle starting control method provided according to an embodiment of the present application;

[0032] Figure 5 A control block diagram of a vehicle starting control method provided according to an embodiment of the present application;

[0033] Figure 6 A specific flow chart of a vehicle starting control method provided according to an embodiment of the present application;

[0034] Figure 7 This is an example diagram of a vehicle starting control device provided according to an embodiment of the present application;

[0035] Figure 8It is a schematic diagram of the structure of a vehicle provided according to an embodiment of the present application. DETAILED DESCRIPTION

[0036] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limiting the present application.

[0037] Before describing the solution of the present application, the vehicle driving anti-skid control system and the control of the driving anti-skid control system in the prior art are first introduced, as follows:

[0038] In the prior art TC, the wheel speed sensor transmits the wheel rotation signal, the steering wheel angle sensor transmits the wheel angle signal, and the IMU sensor transmits the yaw, ax, and ay signals to the hydraulic control unit. The ECU processes and judges the signals of each sensor, sends instructions to the power system to adjust the drive torque output, and simultaneously sends instructions to the hydraulic control unit to adjust the pressure of the brake line to assist the vehicle in driving and starting.

[0039] The control links of the above TC mainly include drive control and brake control:

[0040] The goal of driving torque control is to stabilize the driving wheel speed, that is, to control the driving slip rate of the driving wheel to prevent the driving wheel from slipping excessively and causing vehicle instability.

[0041] When the average of the actual driving slip rate of the coaxial drive wheel exceeds the maximum slip rate allowed by the system and reaches a certain length of time, the torque controller will be activated. Assuming that the moving speed of the wheel center is v ref , the average speed of the driving wheel is v p , the maximum slip allowed by the system is v s +v offset , when v p -v ref >v s +v offset When the duration exceeds t, the torque controller is activated, so as to perform torque control to achieve the purpose of controlling the slip amount, where v s is called the target slip, v oddset It is called the trigger threshold, t is the trigger waiting time. From the above formula, it can be found that modifying the target slip amount or modifying the trigger threshold value can affect the trigger sensitivity of torque control.

[0042] In order to limit the continuous large amount of slip when the vehicle accelerates (usually prone to occur on medium and low adhesion roads such as ice and snow roads, wet basalt, wet cement, etc.), the torque controller needs to limit the driving torque of the power under certain circumstances. Torque control is a passive control strategy, and the working cycle is obvious slip → torque control activation → slip is controlled.

[0043] Figure 2 The acceleration process of a front-wheel drive vehicle from rest on a low-adhesion road, where v ref is the vehicle reference speed, v Axe is the actual shaft speed, and the drive shaft target speed is v Tar =v s +v offset . When the actual shaft speed exceeds the target shaft speed to a certain extent and continues for a period of time, the torque control is activated, and then the torque reduction control is performed to reduce the actual shaft speed to near the target shaft speed. The torque control does not want to reduce the actual shaft speed to the reference shaft speed when making a torque reduction request, but to keep the actual shaft speed near the target shaft speed. That is, the torque control does not want to reduce the slip of the drive shaft to a very low level. Maintaining a certain slip can give the vehicle a good acceleration performance. The torque controller is linear in nature, but the controlled system is not linear. The way we apply linear controllers to nonlinear systems is to split the controller gain selection into controller-specified gains to describe the quasi-linear segment. There is no perfect way to linearize a nonlinear system. Therefore, although this method is simple, it requires a certain degree of compromise and is quite subjective.

[0044] In order to achieve the above control objectives, a commonly used excellent feedback control strategy is usually selected: PID feedback control. This is a feedback control strategy that is widely used in industrial control. PID control is divided into: proportional control P, integral control I, and differential control D.

[0045] The PI torque expression is:

[0046]

[0047] Where, e is the control error,

[0048] e(t)=v s -v p ;

[0049] Where v s is the target shaft speed; v p is the actual shaft speed; K P is the proportionality coefficient; K i is the integral coefficient; K d is the differential coefficient.

[0050] Therefore, in the actual engineering application process, K is constantly adjustedP , K i , K d The control deviation e gradually tends to 0, and the control deviation e and T PID There doesn't have to be a mathematical connection between them.

[0051] In the design of the drive torque controller, the I part is the most important part of the drive torque controller. The design of the starting point of the I-term integration must consider the potential of the road surface in the longitudinal driving direction, while also taking into account the cornering stability. In the first cycle of the torque controller activation, the I part must be initialized to a suitable torque value to improve the driving ability. The initial torque value is not set to 0 every time. However, considering the cornering stability, it is important to set the I item to 0 or even a negative value. Different factors need to be considered for the setting of the starting point of the I-term integration, and the basic value still comes from the torque value of the powertrain.

[0052] Braking torque controller:

[0053] When one wheel is on a low-attachment road, the ground has poor adhesion to the tire, so the driving torque output by the engine is almost completely converted into the rotational kinetic energy of the low-attachment wheel. At this time, although the high-attachment wheel has good adhesion conditions, it cannot accelerate the vehicle due to weak driving force. Braking control can effectively limit the wheel transition slip by applying a certain braking torque to the low-attachment wheel to prevent excessive conversion of driving force into kinetic energy of the low-attachment wheel. In the end, the surplus power will be transmitted to the high-attachment wheel. In order to improve the acceleration performance of the vehicle when the driving wheel torque is sufficient, the resistance of the low-attachment wheel must be increased. Braking control is to achieve the acceleration of the vehicle by applying different degrees of braking torque to the low-attachment wheel to adjust the resistance torque of the road to the high-attachment side.

[0054] When the low-attachment vehicle slips, the degree of slip can be effectively limited by applying braking torque to the low-attachment wheel. However, like the driving torque control, the braking torque control does not want to control the slip of the low-attachment wheel to a very low level where no obvious slip is observed. When the braking control is triggered, the braking torque of the low-attachment side needs to be adjusted in real time so that the wheel speed of the low-attachment side is always around the set target wheel speed.

[0055] Figure 3 Schematic diagram of the acceleration process when starting on a separated road, where vRe f whl is the reference wheel speed of the low attachment side, vwhl is the actual wheel speed of the low attachment side, and vTar is the target wheel speed of the low attachment side. whl =vRe f whl +vsliptar whl , when vwhl-v Re f whl >vsliptar whl+voffset whl When the duration exceeds t, the brake control is activated. From the above formula, it can be seen that the sensitivity of the brake control activation can be changed by changing the slip amount or modifying the threshold value.

[0056] The PI braking torque expression is:

[0057]

[0058] The control deviation is:

[0059] e(t)=V sl -V sr ;

[0060] Where V sl is the left driving wheel speed; V sr is the right drive wheel speed.

[0061] However, the TC-driven anti-skid control in the related art has not taken into account the driving comfort while improving the driving performance. When the vehicle starts on an open road, as long as there is a difference in adhesion between the left and right sides, TC will request the braking system to apply braking force to the side with low adhesion. Frequent intervention of braking force will affect driving comfort. The intervention of braking is accompanied by a large noise (mechanical friction caused by valve pump actuation and caliper clamping force). Frequent intervention of braking will also increase energy consumption and affect the cruising range of electric vehicles. Moreover, TC-driven anti-skid control does not take into account lateral stability, the difficulty of the driver to control the vehicle, and how to overcome tension. Due to the inconsistency of the longitudinal forces on the left and right sides on the open road, the vehicle will yaw differentially, affecting the lateral stability of the vehicle and increasing the difficulty of the driver to control the steering wheel.

[0062] To this end, the present application provides a vehicle starting control method, in which when the wheel speed difference between the actual wheel speed of the driving wheel on any side and the target wheel speed is greater than an activation threshold, the vehicle's drive anti-skid system can be activated to avoid frequent intervention of braking force, so as to reduce noise and energy consumption, thereby improving the vehicle's cruising range, and according to the vehicle's target driving torque, the drive anti-skid control system is controlled to dynamically output the target braking torque to assist the vehicle in starting, ensure a smooth start of the vehicle, and improve driving safety and comfort.

[0063] Specifically, Figure 4 A schematic flow chart of a vehicle starting control method provided in an embodiment of the present application.

[0064] like Figure 4 As shown, the vehicle starting control method includes the following steps:

[0065] In step S101, the actual wheel speed and target wheel speed of each driving wheel on each side during the vehicle starting process are obtained.

[0066] The target wheel speed is the wheel speed that the vehicle is expected to achieve under specific working conditions.

[0067] It can be understood that the embodiment of the present application can obtain the actual wheel speed vRel_Wheel and the target wheel speed vTar_Wheel of each driving wheel during the vehicle starting process, so as to subsequently determine whether the drive anti-skid control system can be activated based on the wheel speed.

[0068] In step S102 , if the wheel speed difference between the actual wheel speed of the driving wheel on any side and the target wheel speed is greater than the activation threshold, the driving anti-skid control system is activated.

[0069] Different from the activation of the drive anti-skid control system in the prior art, in the related art, when the vehicle starts on a two-way road, as long as there is a difference in adhesion between the left and right sides, TC will request the braking system to apply braking force to the side with low adhesion. The intervention of the braking force causes loud noise and frequent intervention will lead to increased energy consumption. However, in the embodiment of the present application, when the difference between the actual wheel speed and the target wheel speed of the wheel on any side is greater than the activation threshold, indicating that the vehicle has a tendency to slip at this time, the drive anti-skid control system is activated to avoid unnecessary braking force intervention, thereby reducing noise and reducing vehicle energy consumption.

[0070] In step S103, the target driving torque of the vehicle is obtained, and the driving anti-skid control system is controlled to dynamically output a target braking torque according to the target driving torque to assist the vehicle in starting.

[0071] The target driving torque is the driving torque required for the vehicle under the current road condition, and the target braking torque is the braking torque required to assist the vehicle in starting under the current road condition.

[0072] It can be understood that the embodiment of the present application can control the drive anti-skid control system to dynamically output the target braking torque according to the target driving torque to assist the vehicle in starting and ensure that the vehicle can start smoothly.

[0073] In an embodiment of the present application, obtaining the target driving torque of the vehicle includes: obtaining the slope of the road on which the vehicle is currently located, the road adhesion and the slip rate of the wheels; and calculating the target driving torque of the vehicle based on the slope, the road adhesion and the slip rate.

[0074] It can be understood that the present application can calculate the target driving torque of the vehicle according to the slope of the road the vehicle is currently on, the road adhesion and the slip rate of the wheels.

[0075] Among them, the slope can be estimated based on the slope sensor or the longitudinal acceleration calculated by the reference vehicle speed differential and the actual longitudinal acceleration measured by the acceleration sensor in the inertial measurement unit; the road adhesion can be obtained by combining the information provided by the wheel speed sensor and the brake force control module with other vehicle sensors; the slip rate can be monitored by the wheel speed sensor to monitor the speed of each wheel and compared with the vehicle reference speed to calculate the actual slip rate of each drive wheel.

[0076] Specifically, the present application can calculate the slope resistance through the vehicle's own mass and slope, and calculate the maximum allowable driving force of the vehicle based on the road adhesion calculation and the vertical load of the wheel, calculate the preliminary driving torque based on the slope resistance and road adhesion, and adjust the driving torque based on the slip rate feedback. If the slip rate is too high, the driving torque is reduced, and if it is too low, it is appropriately increased. This can be achieved through a PID controller to obtain the target driving torque of the vehicle.

[0077] In an embodiment of the present application, the drive anti-skid control system is controlled to dynamically output a target braking torque according to the target drive torque, including: determining the maximum drive torque of the vehicle according to the slope and road adhesion; and controlling the drive anti-skid control system to dynamically output the target braking torque according to the target drive torque and the maximum drive torque.

[0078] It can be understood that the embodiment of the present application can determine the maximum driving torque of the vehicle according to the slope and road adhesion, and then control the drive anti-skid control system to dynamically output the target braking torque according to the target driving torque and the maximum driving torque.

[0079] In an embodiment of the present application, the drive anti-skid control system is controlled to dynamically output the target braking torque according to the target driving torque and the maximum driving torque, including: if the target driving torque is less than or equal to the maximum driving torque, the braking force enabling and calculation module of the drive anti-skid control system is allowed to be disabled; if the target driving torque is greater than the maximum driving torque, the braking force enabling and calculation module of the drive anti-skid control system is allowed to be enabled to output the target braking torque, or, the braking force enabling and calculation module of the drive anti-skid control system is controlled to output the target braking torque after being downgraded.

[0080] It can be understood that the embodiment of the present application can determine whether to enable the braking force enabling and calculating module of the driving anti-skid control system by comparing the target driving torque and the maximum driving torque, so as to avoid unnecessary braking force intervention when the driving torque of the vehicle can meet the vehicle starting requirement, and reduce the energy consumption and noise of the vehicle, specifically:

[0081] If the target driving torque is less than or equal to the maximum driving torque, indicating that the vehicle can provide sufficient driving force to drive the vehicle at this time, it is allowed to disable the braking force enabling and calculating module of the driving anti-skid control system to reduce unnecessary braking force intervention.

[0082] If the target driving torque is greater than the maximum driving torque, indicating that the vehicle cannot provide sufficient driving torque to drive the vehicle at this time and exceeds the maximum driving limit, the braking force enabling and calculating module of the driving anti-skid control system is allowed to output the target braking torque, or the braking force enabling and calculating module of the driving anti-skid control system is controlled to output the target braking torque after being downgraded.

[0083] It should be noted that the maximum driving torque in the embodiment of the present application is the maximum driving torque that the vehicle can theoretically provide. The embodiment of the present application can also be combined with an actual driving control effect to determine whether to enable the braking force enable and calculation module of the drive anti-skid control system, combining practice and theory to achieve accurate control.

[0084] In an embodiment of the present application, after allowing the braking force enabling and calculation module of the drive anti-skid control system to output the target braking torque, it also includes: obtaining the actual driving torque of each wheel of the vehicle; calculating the first vehicle yaw torque according to the actual driving torque of each wheel, and obtaining the first yaw angular velocity detected by the yaw sensor of the vehicle; determining whether the vehicle meets the target stability requirement based on the first vehicle yaw torque and the first yaw angle; if the vehicle does not meet the target stability requirement, allowing the yaw compensation force and enabling module of the drive anti-skid control system to be enabled, otherwise not allowing the yaw compensation force and enabling module of the drive anti-skid control system to be enabled, wherein the yaw compensation force and enabling module is used to control the non-driven wheels to turn according to the first target turning angle.

[0085] Among them, the target stability requirement is that the vehicle's yaw moment is less than the yaw moment threshold and the yaw angular velocity is less than the yaw angular velocity threshold. The target turning angle is determined according to the vehicle's yaw moment and is used to compensate for the vehicle's yaw moment generated when the vehicle starts. The yaw moment threshold and yaw angular velocity threshold can be set in advance according to specific circumstances.

[0086] It can be understood that, in the embodiment of the present application, after the braking force enabling and calculation module of the drive anti-skid control system is allowed to output the target braking torque, the first vehicle yaw moment can be calculated according to the actual driving torque of each wheel of the vehicle, and the first yaw angular velocity detected by the yaw sensor of the vehicle can be obtained. When the first vehicle yaw moment is less than the yaw moment threshold and the first yaw angular velocity is less than the yaw angular velocity threshold, it indicates that the lateral stability of the vehicle is within an acceptable range and no obvious yaw or deviation will occur. Then, the yaw compensation force and enabling module of the drive anti-skid control system are not allowed to be enabled. Otherwise, the yaw compensation force and enabling module of the drive anti-skid control system are allowed to be enabled. The yaw compensation force and enabling module are used to control the non-driven wheels to turn according to the first target angle to compensate for the yaw moment of the vehicle. For example, the vehicle's FWS (Front Wheel Steering) or RWS (Rear Wheel Steering) can be selected for yaw control according to the specific situation.

[0087] In an embodiment of the present application, after the braking force enabling and calculation module of the driving anti-skid control system is allowed to output the target braking torque, it also includes: obtaining the actual braking torque and the actual driving torque of each wheel of the vehicle; calculating the second vehicle yaw moment according to the actual braking torque and the actual driving torque of each wheel, and obtaining the second yaw angular velocity detected by the yaw sensor of the vehicle; determining whether the vehicle meets the target stability requirement based on the second vehicle yaw moment and the second yaw angle; if the vehicle does not meet the target stability requirement, enabling the yaw compensation force and enabling module of the driving anti-skid control system is allowed, otherwise enabling the yaw compensation force and enabling module of the driving anti-skid control system is not allowed, wherein the yaw compensation force and enabling module is used to control the non-driven wheels to turn according to the second target turning angle.

[0088] It can be understood that, in the embodiment of the present application, after the braking force enabling and calculation module of the driving anti-skid control system is allowed to output the target braking torque, the second vehicle yaw moment can be calculated according to the actual driving torque and the actual braking torque of each wheel of the vehicle, and the second yaw angular velocity detected by the yaw sensor of the vehicle can be obtained. When the second vehicle yaw moment is less than the yaw moment threshold and the yaw angular velocity is less than the yaw angular velocity threshold, the yaw compensation force and enabling module of the driving anti-skid control system are allowed to be enabled, otherwise the yaw compensation force and enabling module of the driving anti-skid control system are not allowed to be enabled, wherein the yaw compensation force and enabling module are used to control the non-driven wheels to turn according to the second target turning angle.

[0089] In an embodiment of the present application, the braking force enabling and calculation module of the driving anti-skid control system is enabled to output the target braking torque, including: determining the target braking torque according to the current operating condition of the vehicle; the braking force enabling and calculation module of the driving anti-skid control system is controlled to output the target braking torque after being downgraded, including: determining the target braking torque according to the current operating condition and braking level of the vehicle.

[0090] It can be understood that the embodiments of the present application can determine the target braking torque based on the current operating conditions of the vehicle, such as whether it is accelerating, decelerating, turning or skidding, and the road conditions. The target braking torque can be pre-set according to the operating conditions, or the target braking torque can be determined based on the current operating conditions and braking level of the vehicle.

[0091] The vehicle starting control method of the present application embodiment is described below through a specific embodiment. The control block diagram is as follows: Figure 5 The specific process is as shown in Figure 6 As shown, including:

[0092] Step 1: Identify the oncoming road and estimate the slope based on the sensor signal and control status signal.

[0093] 1. Split road identification: Calculate the target braking torque MbTa__L and MbTar_R (right target braking torque) on the left and right sides of the vehicle according to the braking force control module, calculate the absolute value of the deviation MDiff, compare the absolute value of the left and right target braking torque deviation with MDiff_x, and judge the stability of the wheels at the same time. If MDiff>MDiff_SplitSet and at least one wheel is stable, it is considered that the vehicle is on a split road and the split road flag is set.

[0094] 2. Slope estimation: Compare the acceleration a_VehX calculated by differentiation of the reference vehicle speed with the ax value measured by the ax sensor. When the vehicle speed is less than a certain value, the slope can be estimated.

[0095] Step 2: Calculate the yaw moment of the vehicle based on the actual driving force and braking force of each wheel.

[0096] The vehicle yaw moment can be calculated based on the single-wheel braking force MbWheel_FL / MbWheel_FR / MbWheel_RL / MbWheel_RR fed back by the underlying hydraulic actuator and the single-wheel driving force MF_FL / MF_FR / MF_RL / MF_RR fed back by the power system, and taking into account the influence of the wheel inertia moment.

[0097] Step 3: The braking force calculation and enabling decision module calculates the maximum target braking force of a single wheel and decides whether to enable braking control based on lateral stability and driving requirements.

[0098] The braking force calculation and enabling module will determine whether to activate the braking control based on the difference e_Wheel between the actual wheel speed vRel_Wheel and the target wheel speed vTar_Wheel on the left and right sides. It will determine whether the braking control needs to be activated from the perspective of meeting the best drivability, and select different control parameters according to different working conditions to calculate the braking torque required under the current working conditions. At the same time, the module will determine the optimal differential braking torque based on the driver's throttle input, steering wheel angle input, actual yaw angular velocity of the vehicle, and the amount of differential braking applied under the current road conditions to meet both driving requirements and stability requirements, and enable or disable the braking control.

[0099] Step 4: The yaw compensation torque enabling decision module determines whether the actual value reaches the threshold value of steering intervention based on the vehicle yaw characteristics under the integrated control of driving and braking. If the threshold value is reached, the rear-wheel steering system RWS or FWS is requested to provide steering assistance. If the threshold value is not reached, the steering system is not requested.

[0100] And according to the yaw moment dMz rear wheel angle α / front wheel angle β relationship table set inside the software, the rear wheel steering system RWS or FWS is requested to perform steering assistance and control.

[0101] In summary, the embodiment of the present application estimates the torque required to drive the entire vehicle through the ramp estimation and open road recognition modules, and determines the optimal braking torque by setting the braking force control enabling module and the optimal braking force decision module, thereby improving the starting driving comfort and saving energy while ensuring that the vehicle's driving capability meets the needs.

[0102] Compared with the TC control of the prior art which only considers the driving performance, this application takes into account the stability of driving start. It aims to solve the problem that when the vehicle starts on an open road, the lateral stability of the vehicle deteriorates and it is easy to run off the road due to the existence of asymmetric wheel longitudinal force, which makes it difficult for the driver to control the direction. Steering control is performed by coordinating the rear wheel steering to compensate for the unexpected yaw response caused by the asymmetric braking force / driving force during the acceleration process of the vehicle on the open road, thereby reducing the driver's steering intervention and reducing the unexpected yaw deviation of the vehicle. By setting up a braking force control enabling module, it can be applied to vehicles with a distributed drive architecture, and the braking interface can be closed by estimating the driving capability, and low-select control can be selected, thereby alleviating the impact of braking intervention on the lateral stability of the vehicle to a certain extent.

[0103] According to the vehicle starting control method proposed in the embodiment of the present application, when the speed difference between the actual wheel speed of the driving wheel on any side and the target wheel speed is greater than the activation threshold, the vehicle's drive anti-skid system can be activated to avoid frequent intervention of braking force, so as to reduce noise and energy consumption, thereby improving the vehicle's cruising range. The drive anti-skid control system is controlled to dynamically output the target braking torque according to the vehicle's target driving torque to assist the vehicle in starting, ensure a smooth start of the vehicle, and improve driving safety and comfort.

[0104] Next, the vehicle starting control device proposed according to the embodiment of the present application is described with reference to the accompanying drawings.

[0105] Figure 7 It is a block diagram of a vehicle starting control device according to an embodiment of the present application.

[0106] like Figure 7 As shown, the vehicle starting control device 10 includes: an acquisition module 100 , an activation module 200 and a control module 300 .

[0107] Among them, the acquisition module 100 is used to obtain the actual wheel speed and target wheel speed of the driving wheels on each side during the vehicle starting process; the activation module 200 is used to calculate the wheel speed difference between the actual wheel speed and the target wheel speed of the driving wheels on each side. If the wheel speed difference of the driving wheels on either side is greater than the activation threshold, the vehicle's drive anti-skid control system is activated; the control module 300 is used to obtain the vehicle's target driving torque, and control the drive anti-skid control system to dynamically output the target braking torque according to the target driving torque to assist the vehicle starting.

[0108] In the embodiment of the present application, the acquisition module 100 is further used to: obtain the slope of the road on which the vehicle is currently located, the road adhesion and the slip rate of the vehicle; and calculate the target driving torque of the vehicle based on the slope, road adhesion and slip rate.

[0109] In the embodiment of the present application, the control module 300 is further used to: determine the maximum driving torque of the vehicle according to the slope and road adhesion; and control the driving anti-skid control system to dynamically output the target braking torque according to the target driving torque and the maximum driving torque.

[0110] In the embodiment of the present application, the control module 300 is further used to: if the target driving torque is less than or equal to the maximum driving torque, then the braking force enabling and calculation module of the driving anti-skid control system is allowed to be disabled; if the target driving torque is greater than the maximum driving torque, then the braking force enabling and calculation module of the driving anti-skid control system is allowed to be enabled to output the target braking torque, or, the braking force enabling and calculation module of the driving anti-skid control system is controlled to output the target braking torque after being downgraded.

[0111] In the embodiment of the present application, the device 10 of the embodiment of the present application further includes: a first determination module.

[0112] Among them, the first determination module is used to obtain the actual driving torque of each wheel of the vehicle after allowing the braking force enabling and calculation module of the driving anti-skid control system to output the target braking torque; calculate the first vehicle yaw torque according to the actual driving torque of each wheel, and obtain the first yaw angular velocity detected by the yaw sensor of the vehicle; determine whether the vehicle meets the target stability requirement based on the first vehicle yaw torque and the first yaw angle; if the vehicle does not meet the target stability requirement, it is allowed to enable the yaw compensation force and enabling module of the driving anti-skid control system, otherwise it is not allowed to enable the yaw compensation force and enabling module of the driving anti-skid control system, wherein the yaw compensation force and enabling module is used to control the non-driven wheels to turn according to the first target turning angle.

[0113] In the embodiment of the present application, the device 10 of the embodiment of the present application further includes: a second determination module.

[0114] Among them, the second determination module is used to obtain the actual braking torque and actual driving torque of each wheel of the vehicle after allowing the braking force enabling and calculation module of the driving anti-skid control system to output the target braking torque; calculate the second vehicle yaw moment according to the actual braking torque and the actual driving torque of each wheel, and obtain the second yaw angular velocity detected by the yaw sensor of the vehicle; determine whether the vehicle meets the target stability requirement based on the second vehicle yaw moment and the second yaw angle; if the vehicle does not meet the target stability requirement, it is allowed to enable the yaw compensation force and enabling module of the driving anti-skid control system, otherwise it is not allowed to enable the yaw compensation force and enabling module of the driving anti-skid control system, wherein the yaw compensation force and enabling module is used to control the non-driven wheels to turn according to the second target turning angle.

[0115] In the embodiment of the present application, the target stability requirement is that the vehicle's entire vehicle yaw moment is less than the yaw moment threshold and the yaw angular velocity is less than the yaw angular velocity threshold, and the target turning angle is determined based on the vehicle's entire vehicle yaw moment and is used to compensate for the vehicle's entire vehicle yaw moment generated when the vehicle starts.

[0116] In an embodiment of the present application, the control module 300 is further used to: determine the target braking torque according to the current operating condition of the vehicle; control the braking force enable of the drive anti-skid control system and output the target braking torque after the calculation module is downgraded, including: determining the target braking torque according to the current operating condition and braking level of the vehicle.

[0117] It should be noted that the above explanations of the vehicle starting control method embodiment are also applicable to the vehicle starting control device of this embodiment, and will not be repeated here.

[0118] According to the vehicle starting control device proposed in the embodiment of the present application, when the speed difference between the actual wheel speed of the driving wheel on any side and the target wheel speed is greater than the activation threshold, the vehicle's drive anti-skid system can be activated to avoid frequent intervention of braking force, so as to reduce noise and energy consumption, thereby improving the vehicle's cruising range. The drive anti-skid control system is controlled to dynamically output the target braking torque according to the vehicle's target driving torque to assist the vehicle in starting, ensure a smooth start of the vehicle, and improve driving safety and comfort.

[0119] Figure 8 A schematic diagram of the structure of a vehicle provided in an embodiment of the present application. The vehicle may include:

[0120] A memory 801 , a processor 802 , and a computer program stored in the memory 801 and executable on the processor 802 .

[0121] When the processor 802 executes the program, the vehicle starting control method provided in the above embodiment is implemented.

[0122] Furthermore, the vehicle also includes:

[0123] The communication interface 803 is used for communication between the memory 801 and the processor 802 .

[0124] The memory 801 is used to store computer programs that can be executed on the processor 802 .

[0125] The memory 801 may include a high-speed RAM (Random Access Memory) memory, and may also include a non-volatile memory, such as at least one disk memory.

[0126] If the memory 801, the processor 802 and the communication interface 803 are implemented independently, the communication interface 803, the memory 801 and the processor 802 can be connected to each other through a bus and communicate with each other. The bus can be an ISA (Industry Standard Architecture) bus, a PCI (Peripheral Component Interconnect) bus or an EISA (Extended Industry Standard Architecture) bus, etc. The bus can be divided into an address bus, a data bus, a control bus, etc. For ease of representation, Figure 8 Only one thick line is used in the diagram, but this does not mean that there is only one bus or only one type of bus.

[0127] Optionally, in a specific implementation, if the memory 801, the processor 802 and the communication interface 803 are integrated on a chip, the memory 801, the processor 802 and the communication interface 803 can communicate with each other through an internal interface.

[0128] The processor 802 may be a CPU (Central Processing Unit), or an ASIC (Application Specific Integrated Circuit), or one or more integrated circuits configured to implement the embodiments of the present application.

[0129] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms are not necessarily directed to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or N embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0130] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of this application, "N" means at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0131] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, fragment or portion of code comprising one or N executable instructions for implementing the steps of a custom logical function or process, and the scope of the preferred embodiments of the present application includes alternative implementations in which functions may not be performed in the order shown or discussed, including performing functions in a substantially simultaneous manner or in reverse order depending on the functions involved, which should be understood by technicians in the technical field to which the embodiments of the present application belong.

[0132] It should be understood that the various parts of the present application can be implemented in hardware, software, firmware or a combination thereof. In the above-mentioned embodiments, the steps or methods can be implemented in software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function on a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array, a field programmable gate array, etc.

[0133] A person of ordinary skill in the art may understand that all or part of the steps carried by the method for implementing the above-mentioned embodiment may be completed by instructing related hardware through a program, and the above-mentioned program may be stored in a computer-readable storage medium, which, when executed, includes one of the steps of the method embodiment or a combination thereof.

[0134] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A vehicle starting control method, characterized in that: The following steps are involved: Obtain the actual wheel speed and target wheel speed of each driving wheel on each side during the vehicle starting process; Calculating the wheel speed difference between the actual wheel speed of each driving wheel and the target wheel speed, and activating the driving anti-skid control system of the vehicle if the wheel speed difference of the driving wheel on either side is greater than an activation threshold; The target driving torque of the vehicle is obtained, and the driving anti-skid control system is controlled to dynamically output a target braking torque according to the target driving torque to assist the vehicle in starting.

2. The vehicle starting control method according to claim 1, characterized in that: The obtaining of the target driving torque of the vehicle comprises: Obtaining the slope, road adhesion and wheel slip rate of the road on which the vehicle is currently located; A target driving torque of the vehicle is calculated based on the slope, the road surface adhesion, and the slip ratio.

3. The vehicle starting control method according to claim 2, characterized in that: The step of controlling the drive anti-skid control system to dynamically output a target braking torque according to the target driving torque comprises: Determining the maximum driving torque of the vehicle according to the slope and the road surface adhesion; The drive anti-skid control system is controlled to dynamically output a target braking torque according to the target drive torque and the maximum drive torque.

4. The vehicle starting control method according to claim 3, characterized in that: The step of controlling the drive anti-skid control system to dynamically output a target braking torque according to the target driving torque and the maximum driving torque comprises: If the target driving torque is less than or equal to the maximum driving torque, disabling the braking force enabling and calculating module of the driving anti-skid control system is allowed; If the target driving torque is greater than the maximum driving torque, the braking force enabling and calculating module of the driving anti-skid control system is allowed to output the target braking torque, or the braking force enabling and calculating module of the driving anti-skid control system is controlled to output the target braking torque after being degraded.

5. The vehicle starting control method according to claim 4, characterized in that: After the braking force enabling and calculating module of the drive anti-skid control system is allowed to be disabled to output the target braking torque, the method further includes: Obtaining the actual driving torque of each wheel of the vehicle; Calculating a first vehicle yaw moment according to the actual driving torque of each wheel, and acquiring a first yaw angular velocity detected by a yaw sensor of the vehicle; determining whether the vehicle meets a target stability requirement based on the first vehicle yaw moment and the first yaw angle; If the vehicle does not meet the target stability requirement, the yaw compensation force and enabling module of the drive anti-skid control system are allowed to be enabled; otherwise, the yaw compensation force and enabling module of the drive anti-skid control system are not allowed to be enabled, wherein the yaw compensation force and enabling module are used to control the non-driven wheels to turn according to the first target turning angle.

6. The vehicle starting control method according to claim 4, characterized in that: After the braking force enabling and calculation module of the drive anti-skid control system is enabled to output the target braking torque, the method further includes: Obtaining an actual braking torque and an actual driving torque of each wheel of the vehicle; Calculating a second vehicle yaw moment according to the actual braking torque and the actual driving torque of each wheel, and acquiring a second yaw angular velocity detected by a yaw sensor of the vehicle; determining whether the vehicle meets a target stability requirement based on the second whole vehicle yaw moment and the second yaw angle; If the vehicle does not meet the target stability requirement, the yaw compensation force and enabling module of the drive anti-skid control system are allowed to be enabled; otherwise, the yaw compensation force and enabling module of the drive anti-skid control system are not allowed to be enabled, wherein the yaw compensation force and enabling module are used to control the non-driven wheels to turn according to the second target turning angle.

7. The vehicle starting control method according to claim 5 or 6, characterized in that: The target stability requirement is that the vehicle's whole vehicle yaw moment is less than a yaw moment threshold and the yaw angular velocity is less than a yaw angular velocity threshold. The target turning angle is determined based on the whole vehicle yaw moment and is used to compensate for the whole vehicle yaw moment generated when the vehicle starts.

8. The vehicle starting control method according to claim 4, characterized in that: The step of enabling the braking force enabling and calculating module of the drive anti-skid control system to output a target braking torque includes: Determining the target braking torque according to the current operating condition of the vehicle; The step of controlling the braking force of the drive anti-skid control system to enable and output the target braking torque after the calculation module is downgraded includes: The target braking torque is determined according to the current operating condition and braking level of the vehicle.

9. A vehicle starting control device, characterized in that: include: An acquisition module, used to acquire the actual wheel speed and target wheel speed of each driving wheel on each side during the vehicle starting process; an activation module, configured to calculate a wheel speed difference between an actual wheel speed of a driving wheel on each side and a target wheel speed, and activate a driving anti-skid control system of the vehicle if the wheel speed difference of the driving wheel on either side is greater than an activation threshold; The control module is used to obtain the target driving torque of the vehicle and control the driving anti-skid control system to dynamically output a target braking torque according to the target driving torque to assist the vehicle in starting.

10. A vehicle, characterized in that: include: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the vehicle starting control method according to any one of claims 1 to 8.

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