Vehicle control method and apparatus, and vehicle and storage medium

Abstract

Provided in the present disclosure are a vehicle control method and apparatus, and a vehicle and a storage medium. The method is applied to the field of vehicles, and comprises: when a vehicle is in a direct drive mode, determining whether the vehicle is in an emergency braking condition; if the vehicle is in the emergency braking condition, determining that the vehicle needs to be controlled to exit the direct drive mode, and determining a target torque reduction gradient during the process of the vehicle exiting the direct drive mode; and controlling an engine to reduce torque on the basis of the target torque reduction gradient, and when the output torque of the engine is reduced to a target torque, controlling a clutch of the vehicle to be in an open state, so as to control the vehicle to exit the direct drive mode. By means of the method, a vehicle can be controlled to exit a direct drive mode in advance, thereby avoiding the problem of clutch disengagement delay, preventing an engine from being back-driven, and thus improving the safety of the vehicle.

Description

A vehicle control method, apparatus, vehicle, and storage medium

[0001] This disclosure claims priority to Chinese Patent Application No. 202510069710.8, filed on January 16, 2025, entitled "A method, apparatus, vehicle and storage medium for controlling a vehicle", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This disclosure relates to the field of vehicles, and more particularly to a method, apparatus, vehicle, and storage medium for vehicle control. Background Technology

[0003] With advancements in technology and automotive electronics, four-wheel-drive hybrid vehicles typically offer multiple driving modes, including a direct-drive mode, to meet diverse driving needs. In direct-drive mode, the clutch is engaged, the synchronizer shifts gears, and the front-drive motor, rear-drive motor, and engine are all in driving mode, working together to propel the vehicle.

[0004] When a vehicle is in direct-drive mode and undergoes emergency braking, its speed drops rapidly. Normally, as the speed decreases rapidly, the vehicle should adjust its driving mode, such as disengaging from direct-drive mode. However, in current technology, the vehicle typically needs to slow down to a certain point before disengaging from direct-drive mode. This can lead to the vehicle disengaging from direct-drive mode too late, resulting in the engine and electric motor torque not decreasing quickly enough, causing a delay in clutch engagement. This delay can cause the engine to be dragged (i.e., because the wheel speed is lower than the engine speed, the wheels, through the transmission system, pull the engine, hindering normal engine operation), potentially leading to stalling and compromising vehicle safety. Summary of the Invention

[0005] This disclosure provides a method, apparatus, vehicle, and storage medium for vehicle control. The method enables the vehicle to exit direct drive mode in advance, avoiding clutch opening delay issues, preventing engine back-dragging, and improving vehicle safety.

[0006] Firstly, a vehicle control method is provided, comprising: when the vehicle is in direct drive mode, determining whether the vehicle is in an emergency braking condition; if the vehicle is in an emergency braking condition, determining that the vehicle needs to be controlled to exit the direct drive mode, and determining a target torque reduction gradient during the process of the vehicle exiting the direct drive mode; controlling the engine to reduce torque according to the target torque reduction gradient, and when the output torque of the engine drops to the target torque, controlling the vehicle's clutch to be in an open state, so as to control the vehicle to exit the direct drive mode.

[0007] The aforementioned technical solution, when the vehicle is in direct-drive mode, determines whether the vehicle is in an emergency braking situation. If the vehicle is in an emergency braking situation, it determines that the vehicle needs to exit direct-drive mode. By accurately identifying whether the vehicle is in an emergency braking situation and immediately determining to exit direct-drive mode upon identification, it eliminates the need to wait for the vehicle speed to drop to a certain threshold before exiting direct-drive mode. Compared to existing technologies that only exit direct-drive mode when the vehicle speed drops to a certain value, this allows for earlier control of the vehicle to exit direct-drive mode, enabling a more rapid response to sudden emergency braking situations and avoiding the problem of exiting direct-drive mode too late. Furthermore, it can determine the torque reduction gradient during the vehicle's exit from direct-drive mode, and control the engine to reduce torque based on this gradient. When the engine's output torque drops to the target torque, it controls the vehicle's clutch to engage, thereby controlling the vehicle to exit direct-drive mode. By precisely controlling the torque reduction, it avoids the problem of clutch engagement delay caused by the engine torque not reducing in time, allowing the clutch to disengage in a timely manner according to normal operating logic, thus preventing the engine from being dragged backward and improving vehicle safety.

[0008] In some embodiments, determining whether the vehicle is in an emergency braking condition includes: obtaining the current speed of the vehicle's transmission input shaft and the actual gear position of the vehicle's front axle; and determining whether the vehicle is in an emergency braking condition based on the current speed and the actual gear position of the front axle.

[0009] The above technical solution improves the accuracy of emergency braking judgment by combining the current speed of the transmission input shaft and the actual gear position of the front axle to determine whether the vehicle is in an emergency braking condition, since the relationship between the transmission input shaft speed and the actual gear position of the front axle is different during emergency braking and normal driving.

[0010] In some embodiments, determining whether the vehicle is in an emergency braking condition based on the current rotational speed and the actual gear of the front axle includes: determining whether the actual gear of the front axle meets a preset condition; wherein the preset condition is that the actual gear of the front axle is in a target gear and is not in the process of shifting; if it is determined that the actual gear of the front axle meets the preset condition, determining whether the vehicle is in an emergency braking condition based on the current rotational speed of the transmission input shaft and the actual gear of the front axle; if it is determined that the actual gear of the front axle does not meet the preset condition, obtaining the vehicle's acceleration change rate, and determining whether the vehicle is in an emergency braking condition based on the acceleration change rate, the current rotational speed of the transmission input shaft, and the actual gear of the front axle.

[0011] The above technical solution first determines whether the actual gear position of the front axle meets the preset conditions, and then determines different ways to determine whether the vehicle is in an emergency braking condition for different situations of whether the actual gear position of the front axle meets the preset conditions, which can further improve the accuracy of emergency braking condition judgment.

[0012] In some embodiments, determining whether the vehicle is in an emergency braking condition based on the current speed of the transmission input shaft and the actual gear position of the front axle includes: calculating the rate of change of the transmission input shaft speed; determining a first speed threshold based on the rate of change of the transmission input shaft speed and the actual gear position of the front axle; and determining that the vehicle is in an emergency braking condition if the current speed of the transmission input shaft is less than the first speed threshold.

[0013] The aforementioned technical solution, under normal driving conditions, establishes a certain matching relationship between the transmission input shaft speed and the actual gear position of the front axle. When the actual gear position of the front axle meets preset conditions, the system can accurately analyze whether the vehicle is under emergency braking by determining the current speed of the transmission input shaft and the actual gear position. Furthermore, since the rate of change of the transmission input shaft speed is relatively stable during normal driving but exhibits significant anomalies under emergency braking conditions, the rate of change of the transmission input shaft speed allows for a more accurate determination of whether the vehicle is under emergency braking. Moreover, because different actual gear positions of the front axle result in different transmission input shaft speeds, combining the rate of change of the transmission input shaft speed with the vehicle's actual gear position allows for a more precise determination of whether the vehicle is under emergency braking, reducing the possibility of misjudgment.

[0014] In some embodiments, determining whether the vehicle is in an emergency braking condition based on the rate of change of acceleration, the current speed of the transmission input shaft, and the actual gear position of the front axle includes: determining a second speed threshold based on the rate of change of acceleration and the actual gear position of the front axle; and determining that the vehicle is in an emergency braking condition if the current speed of the transmission input shaft is less than the second speed threshold.

[0015] The above technical solution, when the actual gear position of the front axle does not meet the preset conditions, is not accurate enough in judging whether the vehicle is in an emergency braking condition based on the rotational speed of the transmission input shaft. It can obtain the vehicle acceleration change rate and combine it with the current rotational speed of the transmission input shaft and the change of the actual gear position of the front axle to jointly judge whether the vehicle is in an emergency braking condition, which further improves the reliability and accuracy of emergency braking condition judgment.

[0016] In some embodiments, determining the target torque reduction gradient during the process of the vehicle exiting the direct drive mode includes: acquiring the vehicle's engine air circuit torque request, accelerator pedal opening, current engine speed, and brake pedal opening; determining an initial torque reduction gradient corresponding to the engine air circuit torque request; determining a first coefficient corresponding to the accelerator pedal opening, and determining a second coefficient based on the current engine speed and brake pedal opening; and determining the product of the initial torque reduction gradient, the first coefficient, and the second coefficient as the target torque reduction gradient during the process of the vehicle exiting the direct drive mode.

[0017] The above technical solution determines the initial torque reduction gradient by acquiring the engine's airflow torque request. This closely aligns with the engine's own operating needs, preventing abnormal engine operation due to unreasonable torque reduction. Determining a first coefficient corresponding to the accelerator pedal opening fully considers the driver's current operation, allowing for flexible adjustment of the torque reduction gradient based on driver input. A second coefficient, determined based on the engine's current speed and brake pedal opening, balances the vehicle's braking demands and the engine's actual speed, thus rationally adjusting the torque gradient accordingly. The product of the initial torque gradient, the first coefficient, and the second coefficient is used to determine the target torque reduction gradient. This fully considers multiple key factors such as the engine's operating conditions, the driver's power intentions, and the vehicle's braking status, ensuring that engine torque decreases at an appropriate rate. This facilitates a smooth transition during mode switching, improving overall vehicle performance and driving experience.

[0018] In some embodiments, if the vehicle is in an emergency braking condition, the method further includes: obtaining the current speed of the vehicle's engine; if it is determined that the current speed of the engine is less than a first preset speed, controlling the vehicle's clutch to be in an open state; if it is determined that the current speed of the engine is less than a second preset speed, controlling the engine to be in a stopped state; wherein the second preset speed is less than the first preset speed.

[0019] The above technical solution, by monitoring engine speed in real time and taking timely measures, can effectively avoid operating conditions with incomplete calibration data coverage. When the current engine speed is lower than the first preset speed, timely clutch disengagement can further reduce the risk of engine stalling due to reverse drag. Setting a second preset speed lower than the first preset speed, and promptly controlling the engine to a stopped state when the current engine speed is lower than the second preset speed, and requesting engine shutdown to reset the vehicle's operating mode in cases where the engine has already stalled due to reverse drag, can prevent the operating mode from becoming stuck. Employing a tiered control strategy, taking appropriate measures according to different speed ranges, ensures safety while avoiding unnecessary over-operation. By gradually controlling the state of the clutch and engine, the safety and stability of the vehicle under emergency braking conditions are ensured, reducing the risk of accidents.

[0020] Secondly, a vehicle control device is provided, comprising: a judgment module for determining whether the vehicle is in an emergency braking condition when the vehicle is in direct drive mode; a determination module for determining, if the vehicle is in an emergency braking condition, that the vehicle needs to be controlled to exit the direct drive mode, and determining a target torque reduction gradient during the exit of the direct drive mode; and a control module for controlling the engine to reduce torque according to the target torque reduction gradient, and controlling the vehicle's clutch to be engaged when the engine's output torque drops to the target torque, so as to control the vehicle to exit the direct drive mode.

[0021] In some embodiments, the determination module is specifically used to: obtain the current speed of the transmission input shaft of the vehicle and the actual gear of the front axle of the vehicle; and determine whether the vehicle is in an emergency braking condition based on the current speed and the actual gear of the front axle.

[0022] In some embodiments, the determination module is further configured to: determine whether the actual gear position of the front axle meets a preset condition; wherein the preset condition is that the actual gear position of the front axle is in the target gear and is not in the process of shifting; if it is determined that the actual gear position of the front axle meets the preset condition, determine whether the vehicle is in an emergency braking condition based on the current rotational speed of the transmission input shaft and the actual gear position of the front axle; if it is determined that the actual gear position of the front axle does not meet the preset condition, obtain the vehicle's acceleration change rate, and determine whether the vehicle is in an emergency braking condition based on the acceleration change rate, the current rotational speed of the transmission input shaft and the actual gear position of the front axle.

[0023] In some embodiments, the determination module includes a first determination unit, which is specifically used to: calculate the rate of change of the transmission input shaft speed; determine a first speed threshold based on the rate of change of the transmission input shaft speed and the actual gear position of the front axle; and determine that the vehicle is in an emergency braking condition when the current speed of the transmission input shaft is determined to be less than the first speed threshold.

[0024] In some embodiments, the determination module includes a second determination unit, which is specifically used to: determine a second speed threshold based on the rate of change of acceleration and the actual gear position of the front axle; and determine that the vehicle is in an emergency braking condition when the current speed of the transmission input shaft is determined to be less than the second speed threshold.

[0025] In some embodiments, the determining module is specifically configured to: acquire the engine's air circuit torque request, accelerator pedal opening, current engine speed, and brake pedal opening of the vehicle; determine an initial torque reduction gradient corresponding to the engine's air circuit torque request; determine a first coefficient corresponding to the accelerator pedal opening, and determine a second coefficient based on the current engine speed and the brake pedal opening; and determine the product of the initial torque reduction gradient, the first coefficient, and the second coefficient as the target torque reduction gradient during the process of the vehicle exiting the direct drive mode.

[0026] In some embodiments, the device further includes a second control module, which is specifically configured to: acquire the current speed of the vehicle's engine; control the vehicle's clutch to be in an open state when it is determined that the current speed of the engine is less than a first preset speed; and control the engine to be in a stopped state when it is determined that the current speed of the engine is less than a second preset speed; wherein the second preset speed is less than the first preset speed.

[0027] Thirdly, this disclosure provides a vehicle including 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, causing the vehicle to perform the vehicle control method described in the first aspect or any of the above embodiments.

[0028] Fourthly, this disclosure provides a computer program product comprising: computer program code, which, when executed on a computer, causes the computer to perform the vehicle control method described in the first aspect or any of the above embodiments.

[0029] Fifthly, this disclosure provides a computer-readable storage medium storing computer program code that, when executed on a computer, causes the computer to perform the vehicle control method described in the first aspect or any of the above embodiments. Attached Figure Description

[0030] Figure 1 is a schematic diagram of the structure of a hybrid vehicle provided in an embodiment of this disclosure;

[0031] Figure 2 is a schematic flowchart of a vehicle control method provided in an embodiment of this disclosure;

[0032] Figure 3 is a schematic diagram of the structure of a vehicle control device provided in an embodiment of this disclosure;

[0033] Figure 4 is a structural schematic diagram of a vehicle provided in an embodiment of this disclosure. Embodiments of the present invention

[0034] The technical solutions of this disclosure will now be described clearly and in detail with reference to the accompanying drawings. In the description of the embodiments of this disclosure, unless otherwise stated, " / " means "or," for example, A / B can mean A or B. "And / or" in the text is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Furthermore, in the description of the embodiments of this disclosure, "multiple" refers to two or more than two.

[0035] Hereinafter, the terms "first" and "second" are used for descriptive purposes only and should not be construed as implying or suggesting 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 that feature.

[0036] Figure 1 is a schematic diagram of a hybrid vehicle provided in an embodiment of this disclosure. As shown in Figure 1, the vehicle 100 includes: a front drive motor 101, a rear drive motor 102, an engine 103, a clutch 104, a front axle transmission 105, a rear axle transmission 106, a front axle differential 107, a rear axle differential 108, front wheels, and rear wheels. The front wheels include a left front wheel 1091 and a right front wheel 1092. The rear wheels include a left rear wheel 1101 and a right rear wheel 1102.

[0037] A front-drive motor 101 is mounted on the front axle and provides power to the front wheels via a front-drive driveshaft to drive the vehicle. The front-drive motor 101 is connected to a clutch 104, the first end of which is connected to the engine 103, and the second end of which is connected to the first end of the front axle transmission 105. The second end of the front axle transmission 105 is connected to a front axle differential 107, which is positioned between the left front wheel 1091 and the right front wheel 1092.

[0038] The rear drive motor 102 is mounted on the rear axle and is used to provide power to the rear wheels to drive the vehicle via the rear drive drive shaft. The rear drive motor 102 is connected to the first end of the rear axle transmission 106, and the second end of the rear axle transmission 106 is connected to the rear axle differential 108, which is located between the left rear wheel 1101 and the right rear wheel 1102.

[0039] Hybrid vehicles using the above architecture are equipped with a front-drive motor 101, a rear-drive motor 102, and an engine 103. Therefore, in order to adapt to different road conditions and driving needs, they are usually equipped with multiple operating modes, including direct drive mode and series mode.

[0040] In direct drive mode, the vehicle's clutch 104 is engaged, and the front drive motor 101, rear drive motor 102, and engine 103 are all in driving mode, and the front drive motor 101, rear drive motor 102, and engine 103 work together to drive the vehicle.

[0041] The inventors of this disclosure have discovered that when a vehicle is in direct-drive mode and undergoes emergency braking, its speed drops rapidly. Normally, as the speed drops rapidly, the vehicle should promptly adjust its driving mode, such as disengaging from direct-drive mode. However, in existing technologies, the vehicle typically needs to reduce its speed to a certain value before disengaging from direct-drive mode, which may result in the vehicle disengaging too late. If the vehicle disengages from direct-drive mode too late, the torque of the engine and electric motor may not decrease rapidly enough, leading to a delayed clutch disengagement (the clutch can only disengage when the engine and electric motor torque drops to zero). This delay may cause the engine to be dragged backward (i.e., because the wheel speed is lower than the engine speed, the wheels, through the transmission system, pull the engine backward, hindering normal engine operation), potentially causing stalling and affecting vehicle safety.

[0042] To address the aforementioned technical problems, this disclosure provides a vehicle control method, wherein the executing entity of the method is the vehicle, specifically the hybrid control unit (HCU) within the vehicle.

[0043] Figure 2 is a schematic flowchart of a vehicle control method provided in an embodiment of this disclosure.

[0044] For example, as shown in Figure 2, the method 200 includes:

[0045] S201 determines whether the vehicle is in an emergency braking condition when it is in direct drive mode.

[0046] Direct drive mode refers to an operating mode in which the power output of the engine is directly transmitted to the drive wheels of the vehicle to drive the vehicle without going through an additional gear or transmission conversion; emergency braking mode refers to a driving state in which the driver presses the brake pedal to decelerate or stop the vehicle in an emergency when encountering a sudden situation.

[0047] S202, if the vehicle is in an emergency braking condition, it is determined that the vehicle needs to be controlled to exit the direct drive mode, and the target torque reduction gradient during the process of the vehicle exiting the direct drive mode is determined.

[0048] The target torque reduction gradient refers to the target change range in which the engine torque gradually decreases at a preset rate.

[0049] S203 controls the engine to reduce torque according to the target torque reduction gradient, and when the engine output torque drops to the target torque, it controls the vehicle's clutch to be in the open state in order to control the vehicle to exit the direct drive mode.

[0050] In this embodiment, when the vehicle is in direct drive mode, it is determined whether the vehicle is in an emergency braking situation. If the vehicle is in an emergency braking situation, it is determined that the vehicle needs to exit direct drive mode. By accurately identifying whether the vehicle is in an emergency braking situation, and immediately determining to exit direct drive mode upon identification, it is not necessary to wait for the vehicle speed to drop to a certain threshold before exiting direct drive mode. Compared with the prior art method of exiting direct drive mode only after the vehicle speed drops to a certain value, it is possible to control the vehicle to exit direct drive mode in advance, which can respond more quickly to sudden emergency braking situations and avoid the problem of exiting direct drive mode too late. Furthermore, the torque reduction gradient during the vehicle's exit from direct drive mode can be determined, and the engine torque can be controlled to reduce based on this torque reduction gradient. When the engine output torque drops to the target torque, the vehicle's clutch is controlled to be in the open state to control the vehicle to exit direct drive mode. By precisely controlling the torque reduction, the problem of clutch opening delay caused by the engine torque not being reduced in time can be avoided, allowing the clutch to disengage in a timely manner according to the normal working logic, thereby avoiding the engine being dragged backward and improving vehicle safety.

[0051] The specific implementation of each step in the embodiment shown in Figure 2 is explained below:

[0052] Regarding S201 mentioned above, it's understandable that in direct-drive mode, the power transmission between the engine and wheels is relatively direct. This connection method tightly couples the engine's operating state with the wheel's motion state. Compared to other drive modes, direct-drive mode has a shorter and more direct power transmission path, resulting in a more direct power response. However, this also means that under certain conditions, such as emergency braking, it may trigger more complex powertrain issues. Therefore, when the vehicle is in direct-drive mode, it's crucial to pay close attention to whether the vehicle is in any special operating conditions and take timely measures to ensure vehicle safety.

[0053] Furthermore, when a vehicle is under emergency braking, its speed drops sharply. Since the torque output of the engine and electric motor is designed based on normal driving conditions, if the vehicle is not promptly deactivated from direct drive mode, the engine and electric motor may not be able to adjust their torque in time. This could lead to a mismatch between the torque output and the actual power required by the wheels, increasing the likelihood of an accident.

[0054] Based on this, when the vehicle is in direct drive mode, it is possible to determine in real time whether the vehicle is in an emergency braking condition, so that measures can be taken in a timely manner to ensure the vehicle's safety when the vehicle is in an emergency braking condition.

[0055] In one possible implementation, determining whether a vehicle is in an emergency braking condition includes: obtaining the current speed of the vehicle's transmission input shaft and the actual gear position of the vehicle's front axle; and determining whether the vehicle is in an emergency braking condition based on the current speed and the actual gear position of the front axle.

[0056] It is understood that the aforementioned transmission input shaft refers to the input shaft of the front axle transmission shown in Figure 1. The aforementioned actual front axle gears refer to the actual gears of the front axle transmission shown in Figure 1.

[0057] Furthermore, the aforementioned transmission input shaft refers to the shaft connecting the engine output to the front axle transmission. Specifically, in a vehicle's powertrain, the power generated by the engine is typically transmitted to the transmission input shaft via a clutch. Therefore, the rotational speed of the transmission input shaft is closely related to the engine's rotational speed.

[0058] The current speed of the aforementioned transmission input shaft can be obtained through a speed sensor in the vehicle.

[0059] The actual gear position of the front axle determines the transmission ratio between the input and output shafts of the front axle transmission. Different gear ratios affect the relationship between the input and output shaft speeds, thus influencing the characteristics of the entire power transmission system. The actual gear position of the front axle can be obtained from the vehicle's Electronic Control Unit (ECU) or Transmission Control Unit (TCU).

[0060] Furthermore, during normal vehicle operation, there is a relatively stable matching relationship between the transmission input shaft speed and the actual gear position of the front axle to ensure smooth vehicle operation and power output. However, during emergency braking, the vehicle speed drops sharply, and the wheel speed decreases rapidly. Due to the mechanical connection between the transmission and the wheels, the transmission input shaft speed also drops rapidly, and the rate of decrease far exceeds the rate of change during normal shifting or deceleration. Therefore, the current speed of the transmission input shaft can be obtained to determine whether the vehicle is in an emergency braking situation. Additionally, since the current speed of the transmission input shaft and the actual gear position of the front axle work together to achieve power output during normal vehicle operation, simultaneously obtaining both the current speed of the transmission input shaft and the actual gear position of the front axle allows for accurate identification of whether the vehicle is in an emergency braking situation.

[0061] Under emergency braking conditions, the actual gear position of the front axle usually remains unchanged. However, in certain special circumstances (such as manual shifting by the driver or automatic shifting at a certain speed), the actual gear position of the front axle may change. During this change in the actual gear position, the speed of the transmission input shaft often also changes. Therefore, judging whether the vehicle is under emergency braking based on the current speed of the transmission input shaft when the actual gear position of the front axle changes is inaccurate. Based on this, different methods for determining emergency braking conditions can be developed according to the actual situation of the actual gear position of the front axle.

[0062] In one possible implementation, determining whether a vehicle is in an emergency braking condition based on the current engine speed and the actual gear position of the front axle includes: determining whether the actual gear position of the front axle meets a preset condition; wherein the preset condition is that the actual gear position of the front axle is in a target gear and is not in the process of shifting; if it is determined that the actual gear position of the front axle meets the preset condition, determining whether the vehicle is in an emergency braking condition based on the current engine speed of the transmission input shaft and the actual gear position of the front axle; if it is determined that the actual gear position of the front axle does not meet the preset condition, obtaining the vehicle's acceleration change rate, and determining whether the vehicle is in an emergency braking condition based on the acceleration change rate, the current engine speed of the transmission input shaft, and the actual gear position of the front axle.

[0063] It is understandable that the target gear mentioned above refers to the expected and most suitable gear under the current driving conditions. "Not in the process of shifting" means that the transmission has completed the shift, the current gear is stable, and there is no ongoing shift operation.

[0064] As mentioned above, if the actual gear position of the front axle meets the preset conditions, it means that the actual gear position of the front axle is not in the process of shifting and will not change. Therefore, it is possible to directly determine whether the vehicle is in an emergency braking condition based on the current speed of the transmission input shaft and the actual gear position of the front axle.

[0065] In one possible implementation, determining whether a vehicle is in an emergency braking condition based on the current speed of the transmission input shaft and the actual gear position of the front axle includes: calculating the rate of change of the transmission input shaft speed; determining a first speed threshold based on the rate of change of the transmission input shaft speed and the actual gear position of the front axle; and determining that the vehicle is in an emergency braking condition if the current speed of the transmission input shaft is less than the first speed threshold.

[0066] As can be understood, as mentioned earlier, when a vehicle is under emergency braking, the speed of the transmission input shaft will drop rapidly, and the rate of drop will far exceed the rate of change during normal shifting or deceleration. Therefore, the rate of change of the transmission input shaft speed can be calculated.

[0067] The aforementioned rate of change of the transmission input shaft speed describes how quickly the transmission input shaft speed changes with time. This rate of change of speed = ;in, The change in speed of the transmission input shaft (unit: revolutions per minute, rpm). Indicates the time interval (unit: seconds, s).

[0068] For example, the current speed of the transmission input shaft (2000 rpm) and the speed of the transmission input shaft (1000 rpm) at the time point 5 seconds before the current moment can be obtained, i.e., the above. It is 1000 rpm. Given 5 seconds, the calculated speed change rate of the transmission input shaft is 200 rpm / s.

[0069] Furthermore, after calculating the rate of change of the transmission input shaft speed, a first speed threshold corresponding to the two parameters of the rate of change of the transmission input shaft speed and the actual gear position of the front axle can be determined based on the first preset relationship established in advance.

[0070] It is understandable that the aforementioned first preset relationship is a pre-established table or mapping relationship that can be stored in the vehicle. This first preset relationship can be obtained based on a large amount of experimental data and simulation analysis, defining the maximum speed threshold corresponding to different conditions (the rate of change of speed of different transmission input shafts and different actual gears of the front axle).

[0071] For example, the maximum speed threshold (in rpm) under different conditions (different transmission input shaft speed change rates and different actual front axle gears) can be determined based on a predefined first preset relationship. The aforementioned predefined first preset relationship can be shown in Table 1 below:

[0072] Table 1

[0073]

[0074] As shown in Table 1 above, when the rate of change of speed is the same, the higher the gear, the smaller the corresponding maximum speed threshold will usually be; when the gear is the same, the smaller the absolute value of the rate of change of speed, the larger the corresponding maximum speed threshold will be.

[0075] Understandably, if the actual gear position on the front axle is higher, the transmission ratio is lower, meaning the input and output shaft speeds of the front axle transmission are closer. In this case, the engine or motor speed directly translates to a higher wheel speed, so at the same rate of change of speed, a higher input shaft speed can lead to a rapid increase in vehicle speed. Therefore, when the gear position is higher, a lower maximum speed threshold can be set.

[0076] If the actual gear position of the front axle is low, the transmission ratio is high, meaning the input shaft speed is high and the output shaft speed is low. In this case, the engine or motor speed will not be directly and proportionally reflected at the wheels. Therefore, even if the input shaft speed is high, the actual vehicle speed may be low. Thus, with the same rate of change of speed, a higher maximum speed threshold can be set at lower gears.

[0077] Furthermore, when the absolute value of the rate of change of transmission speed is large, it means that the vehicle is undergoing very rapid deceleration. In this case, even if the gear is the same, a lower maximum speed threshold can be set to ensure that the engine or electric motor does not produce an unstable operating state due to excessively rapid deceleration.

[0078] When the absolute value of the rate of change of transmission speed is small, it means that the vehicle deceleration process is relatively gentle. In this case, a higher maximum speed threshold can be set because there is no immediate safety risk, and the engine or electric motor can continue to operate safely at higher speeds.

[0079] For example, if the calculated speed change rate of the transmission input shaft is -500 rpm / s, and the actual gear position of the front axle is found to be 1st gear, based on the first preset relationship shown in Table 1 above, the corresponding first speed threshold can be determined to be 2800 rpm. If the current speed of the transmission input shaft is found to be 2500 rpm, then it is determined that the current speed of the transmission input shaft is less than the first speed threshold, and it can be determined that the vehicle is in an emergency braking condition.

[0080] Furthermore, as mentioned earlier, if the actual gear position of the front axle does not meet the preset conditions, it indicates that the actual gear position of the front axle may change during gear shifting or because it is not in the target gear. If the actual gear position of the front axle changes, it often leads to a change in the speed of the transmission input shaft. Therefore, when the actual gear position of the front axle changes, determining whether the vehicle is in an emergency braking condition based on the current speed of the transmission input shaft is inaccurate. Based on this, the rate of change of vehicle acceleration can be introduced to determine whether the vehicle is in an emergency braking condition.

[0081] As is understandable, the aforementioned rate of change of acceleration refers to the rate of change of acceleration per unit time, reflecting the trend of vehicle acceleration or deceleration. Under emergency braking conditions, the rate of change of acceleration is typically a large negative value, indicating that the vehicle is rapidly decelerating. Therefore, by monitoring the rate of change of acceleration, one can identify when a vehicle is under emergency braking conditions.

[0082] Under different driving conditions, the rate of change of a vehicle's acceleration will vary. Therefore, the rate of change of acceleration and the actual gear position on the front axle can be combined to determine whether the vehicle is in an emergency braking situation.

[0083] In one possible implementation, determining whether the vehicle is in an emergency braking condition based on the rate of change of acceleration, the current speed of the transmission input shaft, and the actual gear position of the front axle includes: determining a second speed threshold based on the rate of change of acceleration and the actual gear position of the front axle; and determining that the vehicle is in an emergency braking condition if the current speed of the transmission input shaft is less than the second speed threshold.

[0084] Understandably, after obtaining the vehicle's acceleration change rate, a second speed threshold corresponding to the vehicle's acceleration change rate and the actual gear position of the front axle can be determined based on a pre-established second preset relationship.

[0085] Understandably, the aforementioned second preset relationship is also a pre-established table or mapping relationship that can be stored in the vehicle. This second preset relationship can be obtained based on a large amount of experimental data and simulation analysis, defining the maximum speed threshold corresponding to different conditions (different rates of acceleration change and different actual gears on the front axle).

[0086] For example, the maximum speed threshold (in rpm) under different conditions (different rates of acceleration change and different actual gears on the front axle) can be determined based on a predefined second preset relationship. The predefined second preset relationship is shown in Table 2 below:

[0087] Table 2

[0088]

[0089] As shown in Table 2 above, when the rate of change of acceleration is the same, the higher the gear, the smaller the corresponding maximum speed threshold will usually be; when the gear is the same, the smaller the absolute value of the rate of change of acceleration, the larger the corresponding maximum speed threshold will be.

[0090] Understandably, if the front axle is in a higher gear, the transmission ratio is lower, meaning that for the same engine output torque, the wheels receive relatively less torque. With the same rate of change of acceleration, higher gears often require the engine to output more power. Higher input shaft speeds may also require higher engine power, but engine output power is often limited. Setting a high input shaft speed might cause the engine to exceed its preset operating range. Therefore, to prevent the engine from exceeding its preset operating range when the gear is higher, a lower maximum speed threshold can be set.

[0091] If the front axle is actually in a lower gear, the transmission ratio is higher, meaning that for the same engine output torque, the wheels receive a relatively larger torque. With the same rate of change of acceleration, there's no need for the engine to output higher power, so even setting a higher input shaft speed won't cause the engine to exceed its preset operating range. Therefore, with the same rate of change of acceleration, a higher maximum speed threshold can be set at a lower gear.

[0092] Furthermore, a smaller absolute value of the rate of change of acceleration indicates a slower change in vehicle speed. Conversely, a smaller absolute value of the rate of change of acceleration means a lower demand on engine torque output, eliminating the need for rapid increases in engine speed to meet power requirements. In other words, at the same gear, a smaller absolute value of the rate of change of acceleration allows the engine to operate stably under relatively low load. Therefore, at the same gear, a smaller absolute value of the rate of change of acceleration allows for a higher maximum speed threshold for the transmission input shaft. This better adapts to the engine's operating characteristics when the vehicle is in a driving state with a smaller absolute value of the rate of change of acceleration, ensuring smooth and efficient operation of the vehicle's powertrain.

[0093] When the absolute value of the rate of change of acceleration is large, it indicates that the vehicle speed changes faster, and the vehicle's demand for engine torque output is greater. This necessitates the engine to quickly increase its speed to increase power output and meet the power requirements. Since engines have inherent operating range limitations, to prevent the engine from exceeding its reasonable operating range due to excessively high speeds, a lower maximum speed threshold for the transmission input shaft can be set when the absolute value of the rate of change of acceleration is large at the same gear. This ensures stable operation of the vehicle's powertrain and extends the engine's lifespan.

[0094] For example, if the rate of change of vehicle acceleration is found to be -4 m / s² 2 / s, the actual gear position of the front axle is 2nd gear. Based on the second preset relationship shown in Table 2 above, the corresponding second speed threshold can be determined to be 2600 rpm. If the current speed of the transmission input shaft is obtained as 2500 rpm, it is determined that the current speed of the transmission input shaft is less than the second speed threshold, and it can be determined that the vehicle is in an emergency braking condition.

[0095] The above method first determines whether the actual gear position of the front axle meets preset conditions. Then, for different situations where the actual gear position of the front axle meets the preset conditions, different methods are determined to determine whether the vehicle is in an emergency braking condition, which can further improve the accuracy of emergency braking condition judgment. Since there is a certain matching relationship between the speed of the transmission input shaft and the actual gear position of the front axle under normal driving conditions, when it is determined that the actual gear position of the front axle meets the preset conditions, judging whether the vehicle is in an emergency braking condition based on the current speed of the transmission input shaft and the actual gear position of the front axle can accurately analyze whether an emergency braking situation has occurred while the vehicle is driving in normal gears. However, when the actual gear position of the front axle does not meet the preset conditions, judging whether the vehicle is in an emergency braking condition based on the speed of the transmission input shaft is not accurate enough. By obtaining the rate of change of vehicle acceleration and combining it with the current speed of the transmission input shaft and the change in the actual gear position of the front axle, the reliability and accuracy of emergency braking condition judgment can be further improved.

[0096] Furthermore, if it is determined that the vehicle is in an emergency braking condition, the emergency braking indicator in the vehicle can be activated.

[0097] Regarding S202 above, it is understood that if the vehicle is in an emergency braking condition, the emergency braking indicator in the vehicle can be activated immediately. With the emergency braking indicator activated, the direct drive enable indicator in the vehicle can be reset immediately, thus immediately controlling the vehicle to exit direct drive mode.

[0098] Furthermore, the process of disengaging a vehicle from direct drive mode typically involves shifting gears and changing driving modes. If the engine output torque is too high during gear shifting or driving mode switching, it may apply excessive stress to transmission components such as the gearbox and clutch, leading to wear or damage. Therefore, it is necessary to reduce the engine output torque when disengaging a vehicle from direct drive mode.

[0099] Generally, when it is determined that the engine's output torque needs to be reduced, a suitable torque reduction gradient can be determined first.

[0100] For example, the engine's airflow torque request can be obtained, and the corresponding torque reduction gradient can be determined based on the airflow torque request. For instance, if the airflow torque request is low, a higher torque reduction gradient can be set; if the airflow torque request is high, a lower torque reduction gradient can be set.

[0101] Furthermore, if it is determined that the vehicle is in an emergency braking condition and it is necessary to increase the current torque reduction gradient, then the current torque reduction gradient can be corrected by combining the vehicle's operating parameters.

[0102] In one possible implementation, determining the target torque reduction gradient during the process of the vehicle exiting the direct drive mode includes: acquiring the vehicle's engine air circuit torque request, accelerator pedal opening, current engine speed, and brake pedal opening; determining the initial torque reduction gradient corresponding to the engine air circuit torque request; determining a first coefficient corresponding to the accelerator pedal opening, and determining a second coefficient based on the current engine speed and brake pedal opening; and determining the product of the torque value, the first coefficient, and the second coefficient as the target torque reduction gradient during the process of the vehicle exiting the direct drive mode.

[0103] It is understandable that the aforementioned engine intake torque request refers to the expected engine output torque calculated based on the state of the engine intake system. This engine intake torque request reflects the maximum possible torque that the engine can provide under current operating conditions.

[0104] For example, the airflow torque request of the engine can be calculated by the engine controller based on various sensor signals (such as airflow sensor, intake pressure sensor, throttle position sensor, etc.) and a preset control strategy.

[0105] The accelerator pedal opening described above reflects the driver's acceleration demand and is typically expressed as a percentage (0% to 100%). This accelerator pedal opening can be detected by a position sensor installed at the accelerator pedal location.

[0106] The current engine speed mentioned above refers to the engine's current operating speed, which usually affects the engine's operating status.

[0107] The brake pedal opening described above reflects the driver's deceleration needs and is usually expressed as a percentage (0% to 100%). In addition to the brake pedal opening, the driver's deceleration needs can also be determined by obtaining the brake pedal travel, i.e., the distance the brake pedal travels from its initial position to its depressed position. The brake pedal opening can be detected by a position sensor installed at the brake pedal location.

[0108] Furthermore, after obtaining the engine's airflow torque request, the corresponding initial torque reduction gradient can be found in a pre-established initial torque reduction gradient mapping table. This initial torque reduction gradient mapping table is typically established through experiments and simulations, and it contains the initial torque reduction gradients corresponding to different airflow torque request values.

[0109] For example, in the above initial torque reduction gradient mapping table, the smaller the engine's air path torque request value, the larger the corresponding initial torque reduction gradient.

[0110] Understandably, when a vehicle is in an emergency braking situation, it needs to quickly reduce the engine's output torque. If the calculated engine's air circuit torque request value is small, a larger torque reduction gradient needs to be set to ensure that the engine's output torque can be reduced quickly.

[0111] Furthermore, when a vehicle is under emergency braking, the driver usually releases the accelerator pedal, causing the accelerator pedal opening to decrease. Therefore, when calculating the target torque reduction gradient, the accelerator pedal opening can also be considered, and the coefficient of the torque reduction gradient, i.e., the first coefficient, can be determined based on the accelerator pedal opening.

[0112] For example, a mapping table between the accelerator pedal opening and a first coefficient can be established in advance. This mapping table contains the first coefficient corresponding to different accelerator pedal openings. In this mapping table, the larger the accelerator pedal opening, the smaller the first coefficient.

[0113] Furthermore, in order to ensure the safety of the torque reduction process when the vehicle is under emergency braking conditions, the current engine speed and the brake pedal opening can be considered when calculating the target torque reduction gradient, and the coefficient of the torque reduction gradient, i.e., the second coefficient, can be determined based on the current engine speed and the brake pedal opening.

[0114] For example, a second coefficient mapping table can be established in advance between two parameters: the current engine speed and the brake pedal opening, and the second coefficient. This second coefficient mapping table can be shown in Table 3 below:

[0115] Table 3

[0116]

[0117] As shown in Table 3 above, when the current engine speed is the same, the coefficient of torque reduction gradient, i.e., the second coefficient, tends to increase as the brake pedal opening increases; when the brake pedal opening is the same, the coefficient of torque reduction gradient, i.e., the second coefficient, tends to decrease as the current engine speed increases.

[0118] Understandably, a larger brake pedal opening usually indicates a strong braking intention from the driver, requiring a rapid reduction in torque to assist braking. Therefore, given the same engine speed, a larger brake pedal opening allows for a larger second coefficient to be set.

[0119] Conversely, a smaller brake pedal opening may indicate that the driver is only slightly decelerating, in which case an overly rapid torque reduction strategy is not necessary. Therefore, given the same current engine speed, a smaller second coefficient can be set if the brake pedal opening is smaller.

[0120] When the engine's current speed is high, the mechanical components of the engine and transmission system experience greater stress. If the torque reduction is too rapid, these components may be subjected to excessive impact forces, increasing the risk of damage. Therefore, with the same brake pedal opening, a smaller second coefficient can be set if the engine's current speed is high.

[0121] Conversely, at low engine speeds, the engine response is slower, and torque may need to be reduced more quickly to help the vehicle decelerate rapidly. Therefore, with the same brake pedal opening, a larger second coefficient can be set if the current engine speed is lower.

[0122] For example, if the vehicle's engine airflow torque request is 500 N·m, the accelerator pedal opening is 0%, the current engine speed is 1000 rpm, and the brake pedal opening is 60%, based on the initial torque reduction gradient mapping table, the initial torque reduction gradient corresponding to the airflow torque request is determined to be 50 N·m / s; based on the first coefficient mapping table, the first coefficient corresponding to the accelerator pedal opening is determined to be 1.2; based on the second coefficient mapping table, the second coefficient corresponding to the current engine speed and brake pedal opening is determined to be 5. The product of the initial torque reduction gradient, the first coefficient, and the second coefficient is calculated to be 300 N·m / s, therefore the target torque reduction gradient during the vehicle's exit from direct drive mode can be determined to be 300 N·m / s.

[0123] The above method determines the initial torque reduction gradient by acquiring the engine's airflow torque request. This closely aligns with the engine's own operating needs, preventing abnormal engine operation due to unreasonable torque reduction. Determining a first coefficient corresponding to the accelerator pedal opening fully considers the driver's current operation, allowing for flexible adjustment of the torque reduction gradient based on driver input. A second coefficient, determined based on the engine's current speed and brake pedal opening, balances the vehicle's braking demands and the engine's actual speed, thus rationally adjusting the torque gradient accordingly. The product of the initial torque gradient, the first coefficient, and the second coefficient is used to determine the target torque reduction gradient. This method fully considers multiple key factors, including the engine's operating conditions, the driver's power intentions, and the vehicle's braking status, ensuring that engine torque decreases at an appropriate rate. This contributes to a smooth transition during mode switching, improving overall vehicle performance and driving experience.

[0124] Regarding the above S203, it is understood that after determining the target torque reduction gradient, the engine torque can be reduced according to the target torque reduction gradient, and when the engine output torque drops to the target torque, the vehicle's clutch is controlled to be in the open state to control the vehicle to exit the direct drive mode.

[0125] In some embodiments, with the vehicle's clutch in the open state, the target gear of the transmission, the first target speed of the electric motor, and the second target speed of the engine can be determined. The electric motor speed can then be adjusted to the first target speed, the transmission gear can be adjusted to the target gear via the TCU, and the engine speed can be adjusted to the second target speed. After the engine speed is adjusted to the target speed, the clutch can be controlled to close, controlling the vehicle to enter a new driving mode and completing the exit from direct drive mode.

[0126] Understandably, the target gear, first target RPM, and second target RPM can be determined based on the new driving mode to be entered.

[0127] For example, if the vehicle switches from direct drive mode to series mode, the above target gear is the gear corresponding to the series mode, the above first target speed is the speed suitable for the motor to work in the series mode, and the above second target speed is the speed suitable for the engine to work in the series mode.

[0128] For example, to reduce power transmission conflicts and shocks during mode switching and ensure a smooth transition of the power system, the vehicle's clutch can be disengaged only when the engine's output torque drops to 0 N·m. That is, the aforementioned target torque is set to 0 N·m.

[0129] Furthermore, during the process of controlling the reduction of engine output torque according to the above-mentioned target torque reduction gradient, if the torque reduction is not timely enough due to reasons such as untimely response or abnormal calibration data, resulting in a decrease in engine speed, some remedial measures can be taken quickly to avoid more serious safety problems.

[0130] In one possible implementation, if the vehicle is in an emergency braking condition, the method further includes: obtaining the current speed of the vehicle's engine; if it is determined that the current speed of the engine is less than a first preset speed, controlling the vehicle's clutch to be in an open state; if it is determined that the current speed of the engine is less than a second preset speed, controlling the engine to be in a stopped state; wherein the second preset speed is less than the first preset speed.

[0131] Understandably, the first preset speed can be set according to actual needs. For example, it can be set to a speed slightly lower than the engine speed during normal operation, such as 700 rpm.

[0132] If the current engine speed is lower than the first preset speed, it means that the current engine speed is lower than the normal operating speed, and there is a risk that the engine will be dragged off and stall. In order to avoid the engine being dragged off and stalling, an emergency clutch disengagement request can be sent to the TCU immediately.

[0133] By urgently disengaging the clutch, the connection between the engine and the transmission system can be cut off, effectively preventing the engine from stalling due to the wheels dragging it backwards.

[0134] It should be understood that if the engine's current speed is lower than the first preset speed, emergency clutch disengagement may occur before the engine torque decreases to the target torque. Since the current engine speed is detected to be lower than the first preset speed, indicating a risk of engine stalling, the clutch is disengaged immediately to prevent stalling.

[0135] Furthermore, if the engine's current speed is lower than the first preset speed, the above-mentioned operation of exiting direct drive mode can be continued after the clutch is disengaged in an emergency.

[0136] For example, the second preset speed can also be set according to actual needs, such as being lower than the first preset speed, such as 400 rpm.

[0137] If the current engine speed is lower than the second preset speed, it indicates that the current engine speed is already very low, and the engine may even have been stalled due to reverse drag. To avoid the vehicle's power system experiencing a stuck operating mode, the engine can be requested to stop, resetting the vehicle's target operating mode and actual operating mode to pure electric mode, thereby allowing the vehicle's power system to return to a relatively stable operating state.

[0138] Understandably, when the engine has been stalled by reverse drag, the first priority is to ensure the safety of the vehicle. Usually, it is advisable to pause the routine operation of exiting direct drive mode, because the vehicle is in an unstable state after emergency braking. If complex operations such as adjusting gears or motor speed are performed, it may interfere with the vehicle's braking process or cause other unpredictable problems in the power system.

[0139] If the engine is already off, you can first stop the engine and then switch the vehicle's driving mode to pure electric mode to safely stop the vehicle and ensure its safety.

[0140] The above method, by monitoring engine speed in real time and taking timely measures, can effectively avoid operating conditions where calibration data coverage is incomplete. When the current engine speed is lower than the first preset speed, timely clutch disengagement can further reduce the risk of engine stalling due to reverse drag. Setting a second preset speed lower than the first preset speed, and promptly controlling the engine to a stopped state when the current engine speed is lower than the second preset speed, can help reset the vehicle's operating mode by requesting engine shutdown in cases where the engine has already stalled due to reverse drag, preventing the operating mode from becoming stuck. Employing a tiered control strategy, taking appropriate measures according to different speed ranges, ensures safety while avoiding unnecessary over-operation. By gradually controlling the state of the clutch and engine, the safety and stability of the vehicle under emergency braking conditions are ensured, reducing the risk of accidents.

[0141] Figure 3 is a schematic diagram of the structure of a vehicle control device provided in an embodiment of this disclosure.

[0142] For example, as shown in FIG3, the device 300 includes:

[0143] The judgment module 301 is used to determine whether the vehicle is in an emergency braking condition when the vehicle is in direct drive mode.

[0144] The determination module 302 is used to determine if the vehicle is in an emergency braking condition, and to determine the target torque reduction gradient during the process of the vehicle exiting the direct drive mode.

[0145] The control module 303 is used to control the engine to reduce torque according to the target torque reduction gradient, and when the output torque of the engine drops to the target torque, control the clutch of the vehicle to be in the open state so as to control the vehicle to exit the direct drive mode.

[0146] In one possible implementation, the determination module is specifically used to: obtain the current speed of the vehicle's transmission input shaft and the actual gear position of the vehicle's front axle; and determine whether the vehicle is in an emergency braking condition based on the current speed and the actual gear position of the front axle.

[0147] In one possible implementation, the judgment module is further specifically used to: determine whether the actual gear position of the front axle meets a preset condition; wherein the preset condition is that the actual gear position of the front axle is in the target gear and is not in the process of shifting; if it is determined that the actual gear position of the front axle meets the preset condition, determine whether the vehicle is in an emergency braking condition based on the current speed of the transmission input shaft and the actual gear position of the front axle; if it is determined that the actual gear position of the front axle does not meet the preset condition, obtain the vehicle's acceleration change rate, and determine whether the vehicle is in an emergency braking condition based on the acceleration change rate, the current speed of the transmission input shaft, and the actual gear position of the front axle.

[0148] In one possible implementation, the judgment module includes a first judgment unit, which is specifically used to: calculate the rate of change of the transmission input shaft speed; determine a first speed threshold based on the rate of change of the transmission input shaft speed and the actual gear position of the front axle; and determine that the vehicle is in an emergency braking condition when the current speed of the transmission input shaft is determined to be less than the first speed threshold.

[0149] In one possible implementation, the judgment module includes a second judgment unit, which is specifically used to: determine a second speed threshold based on the rate of change of acceleration and the actual gear position of the front axle; and determine that the vehicle is in an emergency braking condition when the current speed of the transmission input shaft is determined to be less than the second speed threshold.

[0150] In one possible implementation, the determining module is specifically used to: obtain the engine's air circuit torque request, accelerator pedal opening, current engine speed, and brake pedal opening of the vehicle; determine the initial torque reduction gradient corresponding to the engine's air circuit torque request; determine a first coefficient corresponding to the accelerator pedal opening, and determine a second coefficient based on the current engine speed and the brake pedal opening; and determine the product of the initial torque reduction gradient, the first coefficient, and the second coefficient as the target torque reduction gradient during the process of the vehicle exiting the direct drive mode.

[0151] Optionally, the device further includes a second control module, which is specifically used to: acquire the current speed of the vehicle's engine; control the vehicle's clutch to be in an open state when it is determined that the current speed of the engine is less than a first preset speed; and control the engine to be in a stopped state when it is determined that the current speed of the engine is less than a second preset speed; wherein the second preset speed is less than the first preset speed.

[0152] Figure 4 is a structural schematic diagram of a vehicle provided in an embodiment of this disclosure.

[0153] For example, as shown in FIG4, the vehicle 400 includes a memory 401 and a processor 402, wherein the memory 401 stores executable program code 4011, and the processor 402 is used to call and execute the executable program code 4011 to perform a vehicle control method.

[0154] Furthermore, embodiments of this disclosure also protect an apparatus that may include a memory and a processor, wherein the memory stores executable program code, and the processor is used to call and execute the executable program code to perform a vehicle control method provided in embodiments of this disclosure.

[0155] This embodiment can divide the device into functional modules based on the above method example. For example, each module can correspond to a separate function, or two or more functions can be integrated into one processing module. The integrated module can be implemented in hardware. It should be noted that the module division in this embodiment is illustrative and only represents one logical functional division. In actual implementation, there may be other division methods.

[0156] When each functional module is divided according to its corresponding function, the device may also include a judgment module, a determination module, and a control module. It should be noted that all relevant content regarding the steps involved in the above method embodiments can be referenced from the functional descriptions of the corresponding functional modules, and will not be repeated here.

[0157] It should be understood that the device provided in this embodiment is used to execute the above-described vehicle control method, and therefore can achieve the same effect as the above-described implementation method.

[0158] When using 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 can be used to control and manage the vehicle's movements. The storage module can be used to support the vehicle in executing relevant program code and data.

[0159] The processing module may be a processor or a controller, which can implement or execute various exemplary logic blocks, modules, and circuits shown in conjunction with the present disclosure. The processor may also be a combination of functions that implement computing capabilities, such as a combination of one or more microprocessors, a combination of digital signal processing (DSP) and a microprocessor, etc., and the storage module may be a memory.

[0160] In addition, the apparatus provided in the embodiments of this disclosure may specifically be a chip, component or module. The chip may include a connected processor and a memory. The memory is used to store instructions. When the processor calls and executes the instructions, the chip can execute a vehicle control method provided in the above embodiments.

[0161] This embodiment also provides a computer-readable storage medium storing computer program code. When the computer program code is run on a computer, the computer executes the above-described related method steps to implement a vehicle control method provided in the above embodiment.

[0162] This embodiment also provides a computer program product that, when run on a computer, causes the computer to perform the aforementioned steps to implement a vehicle control method provided in the above embodiment.

[0163] In this embodiment, the device, computer-readable storage medium, computer program product, or chip are all used to execute the corresponding methods provided above. Therefore, the beneficial effects they can achieve can be referred to the beneficial effects in the corresponding methods provided above, and will not be repeated here.

[0164] Through the above description of the embodiments, those skilled in the art will understand that, for the sake of convenience and brevity, only the division of the above functional modules is used as an example. In actual applications, the above 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.

[0165] In the embodiments provided in this disclosure, it should be understood that the disclosed apparatus and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of modules or units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another device, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection of devices or units may be electrical, mechanical, or other forms.

[0166] The above description is merely a specific embodiment of this disclosure, but the scope of protection of this disclosure is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this disclosure should be included within the scope of protection of this disclosure. Therefore, the scope of protection of this disclosure should be determined by the scope of the claims.

Claims

1. A method for controlling a vehicle, wherein, The method includes: When the vehicle is in direct drive mode, determine whether the vehicle is in an emergency braking condition. If the vehicle is in an emergency braking condition, it is determined that the vehicle needs to be controlled to exit the direct drive mode, and the target torque reduction gradient during the process of the vehicle exiting the direct drive mode is determined. The engine torque is reduced according to the target torque reduction gradient, and when the engine output torque drops to the target torque, the vehicle clutch is opened to control the vehicle to exit the direct drive mode.

2. The method according to claim 1, wherein, The determination of whether the vehicle is in an emergency braking condition includes: Obtain the current speed of the vehicle's transmission input shaft and the actual gear position of the vehicle's front axle; Based on the current speed and the actual gear position of the front axle, determine whether the vehicle is in an emergency braking condition.

3. The method according to claim 2, wherein, The step of determining whether the vehicle is in an emergency braking condition based on the current engine speed and the actual gear position of the front axle includes: Determine whether the actual gear position of the front axle meets a preset condition; wherein, the preset condition is that the actual gear position of the front axle is in the target gear and is not in the process of shifting gears; If the actual gear position of the front axle meets the preset conditions, based on the current speed of the transmission input shaft and the actual gear position of the front axle, it is determined whether the vehicle is in an emergency braking condition. If it is determined that the actual gear position of the front axle does not meet the preset conditions, the vehicle's acceleration change rate is obtained, and based on the acceleration change rate, the current speed of the transmission input shaft, and the actual gear position of the front axle, it is determined whether the vehicle is in an emergency braking condition.

4. The method according to claim 3, wherein, The step of determining whether the vehicle is in an emergency braking condition based on the current speed of the transmission input shaft and the actual gear position of the front axle includes: Calculate the rate of change of the rotational speed of the transmission input shaft; A first speed threshold is determined based on the rate of change of the transmission input shaft and the actual gear position of the front axle; If the current speed of the transmission input shaft is determined to be less than the first speed threshold, the vehicle is determined to be in an emergency braking condition.

5. The method according to claim 3, wherein, The determination of whether the vehicle is in an emergency braking condition based on the rate of change of acceleration, the current speed of the transmission input shaft, and the actual gear position of the front axle includes: Based on the rate of change of acceleration and the actual gear position of the front axle, a second speed threshold is determined; If the current speed of the transmission input shaft is determined to be less than the second speed threshold, the vehicle is determined to be in an emergency braking condition.

6. The method according to claim 1, wherein, Determining the target torque reduction gradient during the process of the vehicle exiting the direct drive mode includes: The engine's air circuit torque request, accelerator pedal opening, current engine speed, and brake pedal opening of the vehicle are obtained. Determine the initial torque reduction gradient corresponding to the airflow torque request of the engine; A first coefficient corresponding to the opening of the accelerator pedal is determined, and a second coefficient is determined based on the current engine speed and the opening of the brake pedal; The product of the initial torque reduction gradient, the first coefficient, and the second coefficient is determined as the target torque reduction gradient during the process of the vehicle exiting the direct drive mode.

7. The method according to claim 1, wherein, If the vehicle is in an emergency braking situation, the method further includes: Obtain the current engine speed of the vehicle; If it is determined that the current speed of the engine is less than the first preset speed, the clutch of the vehicle is controlled to be in the open state. If it is determined that the current speed of the engine is less than the second preset speed, the engine is controlled to be in a stopped state; wherein the second preset speed is less than the first preset speed.

8. The method according to any one of claims 1 to 6, wherein, The control of the vehicle's clutch to be in the open state, in order to control the vehicle to exit the direct drive mode, includes: With the vehicle's clutch in the open state, the target gear of the vehicle's transmission, the first target speed of the electric motor, and the second target speed of the engine are determined. The motor speed is adjusted to the first target speed, the transmission gear is adjusted to the target gear through the transmission control unit, and the engine speed is adjusted to the second target speed; Once it is determined that the engine speed has been adjusted to the target speed, the clutch is controlled to be engaged in order to control the vehicle to exit the direct drive mode.

9. A vehicle control device, wherein, The device includes: The judgment module is used to determine whether the vehicle is in an emergency braking condition when the vehicle is in direct drive mode. The determination module is used to determine, if the vehicle is in an emergency braking condition, that it is necessary to control the vehicle to exit the direct drive mode, and to determine the target torque reduction gradient during the process of the vehicle exiting the direct drive mode. The control module is used to control the engine to reduce torque according to the target torque reduction gradient, and when the output torque of the engine drops to the target torque, control the clutch of the vehicle to be in an open state so as to control the vehicle to exit the direct drive mode.

10. A vehicle, wherein, The vehicles include: Memory, used to store executable program code; A processor for calling and running the executable program code from the memory, causing the vehicle to perform the method as described in any one of claims 1 to 8.

11. A computer-readable storage medium, wherein, The computer-readable storage medium stores a computer program that, when executed, implements the method as described in any one of claims 1 to 8.

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