Drive mode switching method, device and vehicle

Abstract

This application relates to the field of vehicle technology and provides a drive mode switching method, device, and vehicle. The method includes: when a vehicle switches from an electric motor drive mode to an engine drive mode, determining a first target torque required by the engine output; during the adjustment process of adjusting the motor torque to the first target torque, determining the motor speed fluctuation after each adjustment of the motor torque; ensuring that the torque difference between the first target torque and the second target torque is less than a preset torque difference; determining the torque change amount for the next adjustment of the motor torque based on the speed fluctuation, until the adjustment process is complete; increasing the engine torque to the first target torque, and controlling the motor to stop running. Using the above method, the vehicle's drive mode can be smoothly switched from an electric motor drive mode to an engine drive mode.

Description

Technical Field

[0001] This application belongs to the field of vehicle technology, and in particular relates to a drive mode switching method, device and vehicle. Background Technology

[0002] As global environmental problems become increasingly severe, energy conservation and emission reduction have become crucial tasks for the automotive industry. Therefore, new energy vehicles using hybrid systems are gradually becoming mainstream in the automotive industry due to their ability to reduce fuel consumption and emissions.

[0003] Currently, new energy vehicles with hybrid powertrains have multiple driving modes, such as electric motor drive mode, engine drive mode, and hybrid drive mode. However, in existing hybrid powertrain vehicles, the switching of driving modes involves differences in the dynamic torque output characteristics of the electric motor and the engine. Therefore, when switching from "electric motor drive mode" to "engine drive mode," the amount of fuel injection required by the engine increases rapidly. This causes the engine speed to surge as it prepares to take over the electric motor's driving function, resulting in an uneven transition of the driving mode and causing vehicle vibration. Summary of the Invention

[0004] This application provides a driving mode switching method, device, and vehicle, which can solve the problem of unstable vehicle driving mode switching.

[0005] In a first aspect, embodiments of this application provide a method for switching drive modes, the method comprising:

[0006] When the vehicle switches from electric motor drive mode to engine drive mode, the first target torque required by the engine is determined.

[0007] During the adjustment process of the motor torque to the second target torque, the fluctuation of the motor speed after each adjustment of the motor torque is determined; the torque difference between the first target torque and the second target torque is less than the preset torque difference;

[0008] Based on the speed fluctuations, determine the amount of torque change when adjusting the motor torque for the next time, until the adjustment process is complete;

[0009] Increase the engine torque to the first target torque and control the electric motor to stop running.

[0010] Secondly, embodiments of this application provide a drive mode switching device, the device comprising:

[0011] The first target torque determination module is used to determine the first target torque required by the engine when the vehicle switches from electric motor drive mode to engine drive mode.

[0012] The speed fluctuation determination module is used to determine the speed fluctuation of the motor after each adjustment of the motor torque during the adjustment process of adjusting the motor torque to the second target torque; the torque difference between the first target torque and the second target torque is less than the preset torque difference;

[0013] The torque change determination module is used to determine the torque change when adjusting the motor torque for the next time, based on the speed fluctuation, until the adjustment process is completed.

[0014] The control module is used to increase the engine torque to the first target torque and control the motor to stop running.

[0015] Thirdly, embodiments of this application provide a vehicle including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the method described in the first aspect above.

[0016] Fourthly, embodiments of this application provide a computer-readable storage medium storing a computer program that, when executed by a processor, implements the method described in the first aspect above.

[0017] Fifthly, embodiments of this application provide a computer program product that, when run on a vehicle, causes the vehicle to perform the method described in the first aspect.

[0018] The beneficial effects of this application embodiment compared to the prior art are as follows: When the vehicle switches from motor drive mode to engine drive mode, the switching device can determine the first target torque required by the engine output. Then, during the adjustment process of adjusting the motor torque to the second target torque, the motor speed fluctuation can be determined after each adjustment, so as to reasonably determine the torque change for the next adjustment based on the speed fluctuation, until the adjustment process is complete. Thus, by adjusting the motor torque multiple times, the fluctuation of the motor speed can be smoothly controlled during the adjustment process, reducing vehicle vibration. Simultaneously, the switching device can control the motor to stop running when the engine torque is increased to the first target torque. Based on this, since the engine torque has increased to the first target torque, and the torque difference between the first and second target torques is less than a preset torque difference, when the output torque after the motor stops running is 0, the first target torque continued to be provided by the engine will be close to the second target torque output before the motor stops running. Furthermore, when a sudden change in motor torque occurs during mode switching, causing an interruption in vehicle power, vehicle vibration will not occur, ensuring the smoothness of the mode switching process. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a flowchart illustrating the implementation of a drive mode switching method according to an embodiment of this application;

[0021] Figure 2 This is a schematic diagram of the structure of a drive mode switching device provided in an embodiment of this application;

[0022] Figure 3 This is a schematic diagram of the structure of a vehicle provided in one embodiment of this application. Detailed Implementation

[0023] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of this application. However, those skilled in the art will understand that this application may also be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods have been omitted so as not to obscure the description of this application with unnecessary detail.

[0024] It should be understood that, when used in this application specification and the appended claims, the term "comprising" indicates the presence of the described features, integrals, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or a collection thereof.

[0025] Furthermore, in the description of this application and the appended claims, the terms "first," "second," "third," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0026] As global environmental problems become increasingly severe, energy conservation and emission reduction have become crucial tasks for the automotive industry. Therefore, new energy vehicles using hybrid systems are gradually becoming mainstream in the automotive industry due to their ability to reduce fuel consumption and emissions.

[0027] Hybrid electric vehicles have multiple driving modes, such as electric motor drive mode, engine drive mode, and hybrid drive mode. Specifically, electric motor drive mode is when the engine does not work and the electric motor is driven entirely by the battery; engine drive mode is when neither the battery nor the electric motor works and the transmission system is driven entirely by the engine; hybrid drive mode is when the engine drives the transmission system while the battery also supplies power to the electric motor, essentially meaning the engine and electric motor work in parallel; or the engine generates electricity for the battery, which then drives the electric motor.

[0028] In particular, in existing hybrid electric vehicles, the switching of drive modes involves the difference in dynamic torque output characteristics between the electric motor and the engine. Therefore, when switching from "electric motor drive mode" to "engine drive mode", the amount of fuel injection required by the engine will increase in a short period of time. Consequently, when the engine is preparing to take over the drive from the electric motor, the engine speed will surge, resulting in an unstable switching of the vehicle's drive mode and causing vehicle vibration.

[0029] Furthermore, when the vehicle switches from electric motor drive mode to hybrid drive mode, the connection between the electric motor and the transmission is directly disconnected. The engine and clutch then provide torque to the transmission to power the vehicle. However, because the connection between the electric motor and transmission is directly disconnected without first increasing the engine torque during the switching process, the transmission's input torque momentarily drops to zero. This sudden torque change during the switching process causes vehicle vibration.

[0030] Therefore, to improve the smoothness of the mode switching process, this application provides a drive mode switching method, which can be applied to a drive mode switching device. The drive mode switching device can be an on-board device or a hybrid control unit (HCU), and is not limited thereto. Specifically, the hybrid controller is one of the key components in a new energy vehicle using a hybrid power system, mainly used for vehicle power control and drive mode switching control.

[0031] Please see Figure 1 , Figure 1 The following is a flowchart illustrating the implementation of a drive mode switching method provided in an embodiment of this application. The method includes the following steps:

[0032] S101. When the vehicle switches from electric motor drive mode to engine drive mode, determine the first target torque required for the engine to output.

[0033] In one embodiment, the control of the motor speed is mainly related to the vehicle speed, the final drive ratio (which is the gear ratio of the final drive in the vehicle's drive axle), and the wheel radius. Specifically, the motor speed = vehicle speed × final drive ratio ÷ wheel radius. Since the final drive ratio and wheel radius are constant, and the vehicle speed is related to the motor torque provided during operation, it can be considered that the vehicle speed is related to the operating current of the motor. That is, it can be considered that controlling the motor torque or current can control the motor speed.

[0034] Furthermore, since adjusting engine speed involves both fuel injection quantity and air intake quantity, and these cannot be precisely adjusted, the drive mode switching device's control over engine torque is not precise. Therefore, the drive mode switching method in this embodiment is primarily used for switching the drive mode from "motor drive mode" to "engine drive mode".

[0035] In one embodiment, when the vehicle speed is at the maximum speed set in the electric motor drive mode for an extended period of time, or when the vehicle battery charge is less than a preset charge, or when the driver's operation on the accelerator pedal is detected, the drive mode switching device can determine that the vehicle needs to switch from the electric motor drive mode to the engine drive mode.

[0036] The first target torque is the torque required to achieve the vehicle speed as demanded by the driver, which can be determined based on the driver's control of the accelerator pedal.

[0037] Specifically, the drive mode switching device can monitor the throttle opening of the accelerator pedal inside the vehicle, and then determine the torque corresponding to the throttle opening as the first target torque required by the engine. Here, the throttle opening refers to the throttle opening of the vehicle (which is controlled by the accelerator pedal), and the engine can control the amount of fuel injection according to the throttle opening.

[0038] In one embodiment, the vehicle may be equipped with a throttle sensor to monitor the throttle opening. The drive mode switching device may also be pre-calibrated with various correspondences between throttle opening ranges and torque. This allows the drive mode switching device to determine the throttle opening range after detecting the throttle opening, and thus determine the first target torque required by the engine.

[0039] S102. During the adjustment process of adjusting the motor torque to the second target torque, determine the motor speed fluctuation after each adjustment of the motor torque; the torque difference between the first target torque and the second target torque is less than the preset torque difference.

[0040] In one embodiment, a large-scale adjustment of the motor torque at once can easily cause a significant change in vehicle speed within a short period, resulting in vehicle vibration. Therefore, in this embodiment, multiple adjustment actions can be performed during the adjustment of the motor torque.

[0041] The first target torque may be greater than or less than the initial motor torque. Therefore, the above adjustments include, but are not limited to, increasing or decreasing the motor torque. It is understood that when the motor torque is equal to the first target torque, it is only necessary to maintain the motor torque, that is, there is no need to perform the above S102 and the following S103 steps.

[0042] Specifically, the system ensures smooth mode switching without causing vehicle vibration. The torque difference between the adjusted second target torque and the first target torque is less than or equal to a preset torque difference. For example, this preset torque difference can be 0 or other pre-set values. Preferably, the preset torque difference can be 0, meaning the first target torque and the second target torque are equal.

[0043] In one embodiment, since the motor torque needs to be adjusted multiple times, each adjustment will affect the motor speed. Since speed fluctuations can characterize vehicle speed fluctuations, to reduce vehicle vibration, step S103 can be performed based on speed fluctuations to adjust the motor torque.

[0044] In one embodiment, the rotational speed can be determined based on the time required for the motor gear to complete one revolution. Furthermore, to accurately predict rotational speed fluctuations, the drive mode switching device can collect the time required for the gear to rotate multiple revolutions and determine the gear's rotational speed after the motor torque has been adjusted. Then, the difference between this current gear rotational speed and the gear's rotational speed before adjustment is calculated to obtain the aforementioned rotational speed fluctuation.

[0045] However, determining the rotational speed using the above method is time-consuming. Therefore, to reduce the time required to determine rotational speed fluctuations, the drive mode switching device can acquire multiple angular accelerations of the motor within a preset time after the motor adjusts its torque. Then, the rotational speed fluctuation is determined based on these multiple angular accelerations. For example, the drive mode switching device can characterize the rotational speed fluctuation using either the maximum value or the average value of the multiple angular accelerations.

[0046] The preset time can be set according to actual conditions and is not limited thereto. In this embodiment, the preset time can be less than or equal to the time required for the motor gear to rotate one revolution.

[0047] Specifically, gears typically have multiple tooth grooves as equally spaced teeth. Therefore, the radian angle corresponding to the tooth groove between every two teeth is a fixed value. Based on this, when the motor rotates, the time corresponding to the radian angle corresponding to the rotation of one tooth groove can be counted to calculate the angular acceleration. At this time, since multiple angular accelerations need to be obtained, the aforementioned preset time can be the time required to rotate at least two tooth grooves corresponding to the radian angle.

[0048] In addition, to obtain more accurate speed fluctuations, the maximum value or the average value of multiple angular accelerations can be used to characterize the speed fluctuations.

[0049] It should be noted that if the speed fluctuation is determined based on the motor speed, the gear needs to rotate at least one revolution to obtain one motor speed. Therefore, if the speed fluctuation needs to be determined based on multiple motor speeds, the gear needs to rotate at least multiple revolutions. Thus, in this embodiment, using angular acceleration not only accurately characterizes the motor speed fluctuation but also reduces the required time.

[0050] S103. Based on the speed fluctuation, determine the amount of torque change when adjusting the motor torque for the next time, until the adjustment process is completed.

[0051] In one embodiment, the aforementioned torque change is the torque value at which the motor torque needs to be adjusted. The drive mode switching device can adjust the motor torque for the next cycle based on the current speed fluctuation. Then, after the motor torque changes, steps S102 and S103 are executed again until the adjustment process is complete.

[0052] One of the conditions for determining the completion of the adjustment process is that the adjusted motor torque is the second target torque.

[0053] It is understood that the adjusted motor torque may fluctuate around the second target torque. Therefore, in another embodiment, the adjustment process can be determined to be complete when the torque difference between the adjusted motor torque and the second target torque is less than or equal to a preset value. The preset value can be set according to actual conditions and is not limited thereto.

[0054] In one embodiment, the aforementioned speed fluctuation can characterize the fluctuation range of the motor speed after adjusting the motor torque. The purpose of determining the torque change based on the speed fluctuation is that the drive mode switching device can reasonably adjust the motor torque based on the motor speed change to ensure vehicle stability during the adjustment process.

[0055] Specifically, the drive mode switching device can increase the torque change when the speed fluctuation is determined to be within a first fluctuation range; maintain the torque change when the speed fluctuation is determined to be within a second fluctuation range; and decrease the torque change when the speed fluctuation is determined to be within a third fluctuation range. The values ​​in the second fluctuation range are all greater than the values ​​in the first fluctuation range; and the values ​​in the third fluctuation range are all greater than the values ​​in the second fluctuation range. That is, the minimum value in the second fluctuation range will be greater than the maximum value in the first fluctuation range; and the minimum value in the third fluctuation range will be greater than the maximum value in the second fluctuation range.

[0056] Based on the above explanation, when the speed fluctuation is within the first fluctuation range, the motor speed fluctuation can be considered relatively small. Therefore, in order to allow the motor torque to reach the second target torque as quickly as possible, the torque change can be increased again based on the previous torque change, allowing the motor to adjust the torque more frequently.

[0057] Similarly, when the speed fluctuation is within the second fluctuation range, the motor speed fluctuation can be considered stable, and the previous torque change can be maintained. Conversely, when the speed fluctuation is within the third fluctuation range, the motor speed fluctuation can be considered large. In this case, to maintain vehicle stability, the torque change can be reduced based on the previous torque change.

[0058] The first fluctuation range, the second fluctuation range, the third fluctuation range, and the torque change can all be set according to the actual situation, and there are no restrictions on them.

[0059] Understandably, before the initial torque of the motor needs to be adjusted for the first time, since the initial torque has not yet been adjusted, the motor speed fluctuation is usually within the first fluctuation range. Therefore, the amount of torque change can be increased. Afterward, steps S102 and S103 are repeated until the adjustment process is complete.

[0060] In another embodiment, after determining the speed fluctuation, a pre-set PID control program can be used to perform proportional, integral, and derivative calculations (PID calculations) on parameters such as the speed fluctuation, the current motor torque, and the second target torque to adjust the motor torque. This is not limited to a single method. Specifically, the PID control program uses the error (the difference between the current motor torque and the second target torque) as input to perform PID adjustment to control the output (torque change). The output then acts on the controlled system (motor) and affects the actual motor torque that should be output, thus influencing the error. This process is repeated until the motor torque reaches the second target torque.

[0061] S104. Increase the engine torque to the first target torque and control the motor to stop running.

[0062] In one embodiment, to ensure that the vehicle can still travel at the desired speed after the drive mode switch, the drive mode switching device can first increase the engine torque to a first target torque and then control the motor to stop running. Furthermore, this prevents vehicle vibration when a sudden change in motor torque causes a power interruption during mode switching, ensuring the smoothness of the mode switching process.

[0063] That is, for step S104 above, the process of increasing the engine torque to the first target torque can be performed synchronously with the "adjustment process" of the motor torque in steps S102-S103 above, or they can be performed sequentially, without limitation. Afterwards, when the engine torque is adjusted to the first target torque and the motor torque is adjusted to the second target torque, the motor can be controlled to stop running.

[0064] Specifically, increasing the engine torque to the first target torque can be achieved by the drive mode switching device first determining the first target intake air volume and the first target fuel injection volume required to increase the engine torque to the first target torque. Then, after adjusting the intake air volume to the first target intake air volume, the fuel injection volume is adjusted to the first target fuel injection volume to control the engine to operate under the first target intake air volume and the first target fuel injection volume until the engine torque reaches the first target torque.

[0065] In one embodiment, the intake air volume is typically an increment corresponding to the required increase in torque, and the fuel injection quantity is the amount of fuel to be burned in the incoming air to generate torque to drive the vehicle. Initially, the engine is not running, so its torque is 0. That is, the first target torque is the torque that needs to be increased.

[0066] When determining the first target torque required by the engine, the first target fuel injection quantity can be determined based on the known torque-fuel quantity conversion table, or it can be determined by looking up the table based on the current environmental conditions (such as temperature). There is no limitation on this.

[0067] It should be noted that after determining the first target injection quantity, the first target intake quantity can be determined according to the formula: injection quantity = intake air quantity / air-fuel ratio. Here, the air-fuel ratio refers to the ratio of the mass of air to the mass of fuel in the combustible mixture.

[0068] It's important to note that while the response time for controlling fuel injection is in the millisecond range, changing the intake air volume takes approximately one second. This means that if both the intake air volume and fuel injection volume are adjusted simultaneously, there's a possibility that within one second, the engine's intake air volume may not reach the target intake air volume, while the fuel injection volume has already reached the target injection volume. In this situation, due to the insufficient intake air volume, the gasoline at the target injection volume cannot be completely burned, potentially causing the torque generated during this phase to fall short of the target torque. Furthermore, the incomplete combustion of gasoline will produce a significant amount of pollutants.

[0069] Based on this, after determining the first target intake air volume and the first target fuel injection volume, the intake air volume can be adjusted to the first target intake air volume based on the throttle position, and then the fuel injection volume can be adjusted to the first target fuel injection volume. That is, when adjusting the fuel injection volume to the first target fuel injection volume, the engine already has a sufficient first target intake air volume. This allows for complete combustion of the gasoline at the first target fuel injection volume, ensuring that the torque generated by the engine during this stage reaches the first target torque, and reducing pollutants produced when gasoline is not completely burned.

[0070] It should be added that, since the first target intake air volume and the first target fuel injection volume are theoretical values ​​obtained by looking up tables or calculations, the engine torque may deviate from the first target torque after the engine is operated under the first target intake air volume and the first target fuel injection volume. In this case, the error is usually small. Therefore, the drive mode switching device can determine that the engine torque has reached the first target torque when the torque difference between the engine torque and the first target torque is also less than or equal to a preset value. Alternatively, the engine torque can also be considered to have reached the first target torque after the first target fuel injection volume has been completely burned.

[0071] In this embodiment, when the vehicle switches from motor drive mode to engine drive mode, the switching device can determine the first target torque required by the engine output. Then, during the adjustment process of the motor torque to the second target torque, the motor speed fluctuation can be determined after each adjustment. Based on this speed fluctuation, the torque change for the next adjustment can be reasonably determined until the adjustment process is complete. Thus, by adjusting the motor torque multiple times, the fluctuation of the motor speed can be smoothly controlled during the adjustment process, reducing vehicle vibration. Simultaneously, the switching device can control the motor to stop running when the engine torque is increased to the first target torque. Based on this, since the engine torque has increased to the first target torque, and the torque difference between the first and second target torques is less than a preset torque difference, when the output torque after the motor stops running is 0, the first target torque continued to be provided by the engine will be close to the second target torque output before the motor stopped running. Therefore, when a sudden change in motor torque occurs during mode switching, causing an interruption in vehicle power, vehicle vibration will not occur, ensuring the smoothness of the mode switching process.

[0072] In another embodiment, to further improve the smoothness of the mode switching process, the drive mode switching device can also improve the process of increasing the engine torque to the first target torque. Specifically, after each adjustment of the motor torque, the drive mode switching device can determine the amount of torque increase required for the engine each time. Then, for each torque increase, it determines the second target intake air volume and the second target fuel injection volume required for each increase in engine torque. The engine is controlled to operate within the corresponding second target intake air volume and second target fuel injection volume each time until the engine torque reaches the first target torque.

[0073] As explained above, during the adjustment of the motor torque in steps S102-S103, the engine torque can be simultaneously increased to the first target torque. Furthermore, the increase in engine torque is performed in multiple stages to avoid a sudden, large increase in engine torque that could cause the engine speed to surge, thus ensuring vehicle stability.

[0074] Specifically, determining the required increase in engine torque each time can be achieved by: the drive mode switching device determining the total torque change when the initial torque of the motor is adjusted to the second target torque; then, for any torque change, determining a first ratio between the torque change and the total torque change; and finally, calculating the product of the first ratio and the first target torque to determine the required increase in engine torque each time.

[0075] The initial torque is the torque before the first adjustment of the motor. The torque difference between this initial torque and the second target torque is the total change in motor torque. The aforementioned first ratio can be considered as the torque magnitude of this motor torque adjustment. At this point, the product of the first ratio and the first target torque is calculated to obtain the torque increase. It can be assumed that the increase in engine torque is consistent with the magnitude of each motor torque adjustment. Based on this, during the process of increasing engine torque, it is not only increased in multiple stages but also adjusted at the same magnitude as the motor torque to further ensure vehicle stability during drive mode switching.

[0076] For example, when the first target torque is 20 N·m, the total torque change is 10 N·m, and the torque change is 4 N·m, the first ratio corresponding to the magnitude of the motor torque adjustment is 0.4, and the torque increase of the engine torque adjustment can be 8 N·m.

[0077] In another embodiment, when increasing the engine torque to the first target torque in stages, the torque can also be increased in stages. For example, the ratio of the first target torque to a preset number of times can be used as the torque increase amount, which will not be described in detail here. The preset number of times is the number of times the engine torque needs to be adjusted, and it is a pre-set value.

[0078] The method for determining the second target intake volume and the second target fuel injection volume when the engine torque needs to be increased is similar to the method for determining the first target intake volume and the first target fuel injection volume described above, and will not be explained further.

[0079] It should be added that, after determining the second target intake volume and the second target fuel injection volume, the drive mode switching device can also adjust the intake volume to the first target intake volume and then adjust the fuel injection volume to the first target fuel injection volume, so as to ensure that the gasoline of the second target fuel injection volume is fully burned.

[0080] In summary, according to the above embodiments, when the driving mode switches from "motor drive mode" to "engine drive mode", the motor torque is mainly adjusted according to steps S102-S103, and the engine torque is adjusted using the strategies described in the two embodiments above. This can further enable the vehicle's driving mode to switch smoothly from motor drive mode to engine drive mode.

[0081] Please see Figure 2 , Figure 2 This is a structural block diagram of a drive mode switching device provided in an embodiment of this application. The modules included in the drive mode switching device in this embodiment are used to perform... Figure 1 The steps in the corresponding embodiments. Please refer to the details. Figure 1 as well as Figure 1 The relevant descriptions in the corresponding embodiments are shown below. For ease of explanation, only the parts relevant to this embodiment are shown. See also... Figure 2 The drive mode switching device 200 may include: a first target torque determination module 210, a speed fluctuation determination module 220, a torque change determination module 230, and a control module 240, wherein:

[0082] The first target torque determination module 210 is used to determine the first target torque required by the engine when the vehicle switches from electric motor drive mode to engine drive mode.

[0083] The speed fluctuation determination module 220 is used to determine the speed fluctuation of the motor after each adjustment of the motor torque during the adjustment process of adjusting the motor torque to the second target torque; the torque difference between the first target torque and the second target torque is less than the preset torque difference.

[0084] The torque change determination module 230 is used to determine the torque change amount when adjusting the motor torque for the next time based on the speed fluctuation, until the adjustment process is completed.

[0085] The control module 240 is used to increase the engine torque to the first target torque and control the motor to stop running.

[0086] In one embodiment, the first target torque determination module 210 is further configured to:

[0087] Monitor the accelerator pedal opening in the vehicle; determine the torque corresponding to the accelerator pedal opening as the first target torque required by the engine output.

[0088] In one embodiment, the speed fluctuation determination module 220 is further configured to:

[0089] Within a preset time after the motor adjusts its torque, multiple angular accelerations of the motor are acquired; the speed fluctuation is determined based on these multiple angular accelerations.

[0090] In one embodiment, the speed fluctuation determination module 220 is further configured to:

[0091] The maximum value or the average value of multiple angular accelerations can be used to characterize the rotational speed fluctuation.

[0092] In one embodiment, the torque change determination module 230 is further configured to:

[0093] If the speed fluctuation is determined to be within the first fluctuation range, the torque change is increased; if the speed fluctuation is determined to be within the second fluctuation range, the torque change is maintained; the values ​​in the second fluctuation range are all greater than the values ​​in the first fluctuation range; if the speed fluctuation is determined to be within the third fluctuation range, the torque change is decreased; the values ​​in the third fluctuation range are all greater than the values ​​in the second fluctuation range.

[0094] In one embodiment, the control module 240 is further configured to:

[0095] Determine the first target intake air volume and the first target fuel injection volume required for the engine torque to increase to the first target torque; after adjusting the intake air volume to the first target intake air volume, adjust the fuel injection volume to the first target fuel injection volume; control the engine to operate under the first target intake air volume and the first target fuel injection volume until the engine torque reaches the first target torque.

[0096] In one embodiment, the control module 240 is further configured to:

[0097] After each adjustment of the motor torque, determine the amount of torque increase required for the engine each time; for each torque increase, determine the second target intake volume and the second target fuel injection volume required each time when the engine increases the torque; control the engine to operate in the environment of the corresponding second target intake volume and the second target fuel injection volume each time until the engine torque reaches the first target torque.

[0098] In one embodiment, the control module 240 is further configured to:

[0099] Determine the total torque change when the initial torque of the motor is adjusted to the second target torque; for any torque change, determine the first ratio between the torque change and the total torque change; calculate the product of the first ratio and the first target torque to obtain the torque increase required by the engine each time.

[0100] When it is understood that, Figure 2 In the structural block diagram of the drive mode switching device shown, each module is used to perform... Figure 1 The steps in the corresponding embodiments, and for Figure 1 The steps in the corresponding embodiments have been explained in detail in the above embodiments. Please refer to them for details. Figure 1 as well as Figure 1 The relevant descriptions in the corresponding embodiments will not be repeated here.

[0101] Figure 3 This is a structural block diagram of a vehicle provided in one embodiment of this application. For example... Figure 3 As shown, the vehicle 300 in this embodiment includes a processor 310, a memory 320, and a computer program 330 stored in the memory 320 and executable on the processor 310, such as a program for a drive mode switching method. When the processor 310 executes the computer program 330, it implements the steps in the various embodiments of the drive mode switching methods described above, for example... Figure 1 S101 to S104 are shown. Alternatively, the processor 310 implements the above when executing the computer program 330. Figure 2 The functions of each module in the corresponding embodiments, for example, Figure 2 For details on the functions of modules 210 to 240 shown, please refer to [link / reference]. Figure 2 The relevant descriptions in the corresponding embodiments.

[0102] For example, the computer program 330 can be divided into one or more modules, one or more of which are stored in the memory 320 and executed by the processor 310 to implement the drive mode switching method provided in the embodiments of this application. One or more modules can be a series of computer program instruction segments capable of performing specific functions, which describe the execution process of the computer program 330 in the vehicle 300. For example, the computer program 330 can implement the drive mode switching method provided in the embodiments of this application.

[0103] Vehicle 300 may include, but is not limited to, processor 310 and memory 320. Those skilled in the art will understand that... Figure 3 This is merely an example of vehicle 300 and does not constitute a limitation on vehicle 300. It may include more or fewer components than shown, or combine certain components, or different components. For example, a vehicle may also include input / output devices, network access devices, buses, etc.

[0104] The processor 310 may be a central processing unit, or it may be other general-purpose processors, digital signal processors, application-specific integrated circuits, off-the-shelf programmable gate arrays or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or any conventional processor, etc.

[0105] The memory 320 can be an internal storage unit of the vehicle 300, such as a hard drive or memory of the vehicle 300. The memory 320 can also be an external storage device of the vehicle 300, such as a plug-in hard drive, smart memory card, flash memory card, etc., equipped on the vehicle 300. Furthermore, the memory 320 can include both internal storage units and external storage devices of the vehicle 300.

[0106] This application provides a computer-readable storage medium storing a computer program, which is executed by a processor using the drive mode switching method described in the above embodiments.

[0107] This application provides a computer program product that, when run on a vehicle, causes the vehicle to execute the drive mode switching methods described in the above embodiments.

[0108] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. A method for switching drive modes, characterized in that, The method includes: When the vehicle switches from electric motor drive mode to engine drive mode, the first target torque required by the engine is determined. During the adjustment process of the motor torque to the second target torque, the fluctuation of the motor speed after each adjustment of the motor torque is determined; the torque difference between the first target torque and the second target torque is less than a preset torque difference; Based on the speed fluctuation, determine the amount of torque change when adjusting the motor torque next, until the adjustment process is completed; Increase the torque of the engine to the first target torque, and control the motor to stop running; The step of determining the torque change amount for the next adjustment of the motor torque based on the speed fluctuation includes: If it is determined that the speed fluctuation is within the first fluctuation range, then the torque change is increased; If it is determined that the speed fluctuation is within the second fluctuation range, then the torque change is maintained; the values ​​of the second fluctuation range are all greater than the values ​​of the first fluctuation range. If the speed fluctuation is determined to be within the third fluctuation range, then the torque change is reduced; the values ​​of the third fluctuation range are all greater than the values ​​of the second fluctuation range.

2. The method according to claim 1, characterized in that, Determining the first target torque that the engine needs to output includes: Monitor the accelerator pedal opening in the vehicle; The torque corresponding to the throttle opening is determined as the first target torque that the engine needs to output.

3. The method according to claim 1, characterized in that, The determination of the motor speed fluctuation after each adjustment of the motor torque includes: Within a preset time after the motor adjusts its torque, multiple angular accelerations of the motor are obtained; The rotational speed fluctuation is determined based on the multiple angular accelerations.

4. The method according to claim 3, characterized in that Determining the rotational speed fluctuation based on the plurality of angular accelerations includes: The maximum value or the average value of the plurality of angular accelerations is used to characterize the rotational speed fluctuation.

5. The method according to any one of claims 1-4, characterized in that, Increasing the engine torque to the first target torque includes: Determine the first target intake air volume and the first target fuel injection volume required for the engine torque to increase to the first target torque; After adjusting the intake air volume to the first target intake air volume, adjust the fuel injection volume to the first target fuel injection volume; The engine is controlled to operate under the first target intake air volume and the first target fuel injection volume until the engine torque reaches the first target torque.

6. The method according to any one of claims 1-4, characterized in that, Increasing the engine torque to the first target torque includes: After each adjustment of the motor torque, determine the amount of torque increase required for the engine each time; For each increase in torque, determine the second target intake volume and the second target fuel injection volume required each time the engine increases the torque by that amount; The engine is controlled to operate within the corresponding second target intake volume and second target fuel injection volume each time until the engine torque reaches the first target torque.

7. The method according to claim 6, characterized in that, The step of determining the required increase in engine torque each time after adjusting the motor torque includes: Determine the total torque change when the initial torque of the motor is adjusted to the second target torque; For any of the torque changes, a first ratio of the torque change to the total torque changes is determined; The product of the first ratio and the first target torque is calculated to obtain the amount of torque increase required by the engine each time.

8. A drive mode switching device, characterized in that, The device includes: The first target torque determination module is used to determine the first target torque required by the engine when the vehicle switches from electric motor drive mode to engine drive mode. The speed fluctuation determination module is used to determine the speed fluctuation of the motor after each adjustment of the motor torque during the adjustment process of adjusting the motor torque to the second target torque; the torque difference between the first target torque and the second target torque is less than a preset torque difference; The torque change determination module is used to determine the torque change amount when adjusting the motor torque next, based on the speed fluctuation, until the adjustment process is completed; A control module is used to increase the torque of the engine to the first target torque and control the motor to stop running; The torque change determination module is also used for: If it is determined that the speed fluctuation is within the first fluctuation range, then the torque change is increased; If it is determined that the speed fluctuation is within the second fluctuation range, then the torque change is maintained; the values ​​of the second fluctuation range are all greater than the values ​​of the first fluctuation range. If the speed fluctuation is determined to be within the third fluctuation range, then the torque change is reduced; the values ​​of the third fluctuation range are all greater than the values ​​of the second fluctuation range.

9. A vehicle comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the method as described in any one of claims 1 to 7.

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