Engine shutdown control method and related device

Abstract

The invention discloses an engine shutdown control method and a related device. In response to an obtained shutdown instruction, the torque of an input shaft of a vehicle is reduced, and if the torque of the input shaft is reduced to a torque safety threshold value, an interruption request is sent to disconnect power transmission between the input shaft and an output shaft; torque generated by engine rotating speed fluctuation in the engine shutdown process is prevented from being transmitted to the wheel end, and therefore vibration is restrained. If the power transmission between the input shaft and the output shaft is disconnected, the rotating speed matching request is sent, and the rotating speed of the driving motor is adjusted according to the rotating speed matching condition indicated by the rotating speed matching request, so that the vehicle can be suitable for the mode switching process of the vehicle static working condition and the running working condition; in this way, in the process of switching the multi-power-source mode including the engine to the single-power-source mode for driving the single machine, the rotating speed of the driving motor and the rotating speed of the output shaft can be matched, and vibration generated due to mismatching of the rotating speed is reduced.

Description

Technical Field

[0001] The present invention relates to the field of vehicle technology, and in particular to an engine shutdown control method and related devices. Background Art

[0002] With the development of automobile technology and new energy technology, there are more and more hybrid vehicles. During the process of switching some modes of hybrid vehicles (for example, switching from the dual-drive mode of the engine and the drive motor to the single-drive mode of the drive motor), a shutdown command instructing the engine to shut down will be sent. During the engine shutdown process, the torque generated by the change in engine speed acts on the wheel end, causing the body to vibrate, which brings a bad riding experience to users.

[0003] In the related art, after receiving a shutdown command, the power transmission between the input shaft and the output shaft is generally cut off by sending an interrupt request, thereby suppressing the vibration of the vehicle body during the engine shutdown process. However, this method is applicable to fewer working conditions. Summary of the invention

[0004] In view of the above problems, the present application provides an engine shutdown control method and related devices, which are used to solve the problem that the vibration suppression method during engine shutdown is applicable to fewer working conditions.

[0005] Based on this, this application discloses the following technical solutions:

[0006] In a first aspect, an embodiment of the present application provides an engine shutdown control method, the method comprising:

[0007] In response to obtaining a stop command, reducing an input shaft torque of the vehicle, the input shaft torque including a torque of an engine and a torque of a drive motor;

[0008] If the input shaft torque drops to a torque safety threshold, an interrupt request is sent, wherein the interrupt request is used to disconnect the power transmission between the input shaft and the output shaft;

[0009] If the power transmission between the input shaft and the output shaft is disconnected, a speed matching request is sent, wherein the speed matching request is used to instruct to match the speed of the drive motor with the speed of the output shaft;

[0010] The speed of the driving motor is adjusted according to the speed matching condition indicated by the speed matching request.

[0011] Optionally, the method further comprises:

[0012] After the power transmission between the input shaft and the output shaft is disconnected and before sending a speed matching request, obtaining a current vehicle speed;

[0013] determining a target speed of the drive motor according to the current vehicle speed;

[0014] The driving motor is controlled to adjust the rotation speed of the driving motor toward the target rotation speed.

[0015] Optionally, controlling the driving motor to adjust the speed of the driving motor toward the target speed includes:

[0016] Obtaining the current speed of the driving motor;

[0017] Determine a target speed change rate according to a difference between the current speed and the target speed, wherein the target speed change rate is used to indicate how fast the speed of the drive motor changes. The greater the difference, the greater the target speed change rate, and the faster the speed of the drive motor is adjusted;

[0018] The driving motor is controlled to adjust the speed of the driving motor toward the target speed according to the target speed change rate.

[0019] Optionally, if the current speed includes the i-th current speed, the i-th time is a time from when the power transmission between the input shaft and the output shaft is disconnected to when the speed of the drive motor reaches the target speed, and i is a positive integer, determining the target speed change rate according to the difference between the current speed and the target speed includes:

[0020] Determine the i+1th target speed change rate according to the i-th difference between the target speed and the i-th current speed, wherein the greater the i-th difference, the greater the i+1th target speed change rate, and the faster the speed adjustment of the i+1th drive motor;

[0021] The step of controlling the driving motor to adjust the speed of the driving motor in the direction of the target speed according to the target speed change rate includes:

[0022] At the (i+1)th time, the speed of the drive motor is controlled to be adjusted toward the target speed according to the (i+1)th target speed change rate.

[0023] Optionally, if the interrupt request is a neutral gear switching request, the speed matching request is a backshift request, the neutral gear switching request is used to instruct to switch the initial gear to neutral gear, and the backshift request is used to instruct to switch the neutral gear to the target gear, the method further includes:

[0024] After the initial gear is switched to the neutral gear and before a shift back request is sent, obtaining a current vehicle speed and a conversion relationship between the vehicle speed and the gear;

[0025] Determining the target gear corresponding to the current vehicle speed according to the conversion relationship;

[0026] determining a target speed according to the target gear position;

[0027] The driving motor is controlled to adjust the rotation speed of the driving motor toward the target rotation speed.

[0028] In a second aspect, an embodiment of the present application provides an engine shutdown control device, the device comprising: the device comprising: an acquisition unit, a sending unit and a control unit;

[0029] The acquisition unit is used to reduce the input shaft torque of the vehicle in response to acquiring the shutdown instruction, wherein the input shaft torque includes the torque of the engine and the torque of the drive motor;

[0030] The sending unit is used to send an interrupt request if the input shaft torque decreases to a torque safety threshold, wherein the interrupt request is used to disconnect the power transmission between the input shaft and the output shaft;

[0031] The sending unit is further used to send a speed matching request if the power transmission between the input shaft and the output shaft is disconnected, wherein the speed matching request is used to instruct to match the speed of the drive motor with the speed of the output shaft;

[0032] The control unit is used to adjust the speed of the drive motor according to the speed matching condition indicated by the speed matching request.

[0033] Optionally, the device further includes a vehicle speed unit, a first determination unit and a speed regulating unit:

[0034] The vehicle speed unit is used to obtain the current vehicle speed after the power transmission between the input shaft and the output shaft is disconnected and before sending the speed matching request;

[0035] The first determination unit is used to determine the target speed of the drive motor according to the current vehicle speed;

[0036] The speed regulating unit is used to control the driving motor to adjust the speed of the driving motor toward the target speed.

[0037] In a third aspect, an embodiment of the present application provides a vehicle, the vehicle comprising a processor and a memory:

[0038] The memory is used to store a computer program and transmit the computer program to the processor;

[0039] The processor is configured to execute the method according to the first aspect of claim 1 according to the computer program.

[0040] In a fourth aspect, an embodiment of the present application provides a computer-readable storage medium, wherein the computer-readable storage medium is used to store a computer program, and the computer program is used to execute the method described in the first aspect above.

[0041] In a fifth aspect, an embodiment of the present application provides a computer program product comprising a computer program, which, when executed on a computer device, enables the computer device to execute the method described in the first aspect above.

[0042] It can be seen from the above technical solutions that the present application has at least the following beneficial effects:

[0043] In response to obtaining a shutdown command, the input shaft torque of the vehicle is reduced. If the input shaft torque is reduced to a torque safety threshold, an interrupt request is sent to disconnect the power transmission between the input shaft and the output shaft to prevent the torque generated by the engine speed fluctuation during the engine shutdown process from being transmitted to the wheel end, thereby suppressing vibration. If the power transmission between the input shaft and the output shaft is disconnected, a speed matching request is sent, and the speed of the drive motor is adjusted according to the speed matching condition indicated by the speed matching request, so that the vehicle can be suitable for not only the vehicle static working condition but also the driving working condition. In the process of mode switching, that is, in the process of switching from the multi-power source mode including the engine to the single power source mode of the drive single machine drive, the speed between the drive motor and the output shaft can be matched, thereby reducing the vibration caused by the speed mismatch. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0045] Figure 1 A schematic diagram of a DHT system structure provided in an embodiment of the present application;

[0046] Figure 2 A flow chart of an engine shutdown control method provided in an embodiment of the present application;

[0047] Figure 3 A schematic diagram of the structure of an engine shutdown control device provided in an embodiment of the present application;

[0048] Figure 4 A schematic diagram of the structure of a vehicle provided in an embodiment of the present application;

[0049] Figure 5A flow chart of an engine shutdown control method provided in an embodiment of the present application. DETAILED DESCRIPTION

[0050] The embodiments of the present application will be described in more detail below with reference to the accompanying drawings. Although certain embodiments of the present application are shown in the accompanying drawings, it should be understood that the present application can be implemented in various forms and should not be construed as being limited to the embodiments described herein. Instead, these embodiments are provided to provide a more thorough and complete understanding of the present application. It should be understood that the drawings and embodiments of the present application are only for exemplary purposes and are not intended to limit the scope of protection of the present application.

[0051] Dedicated Hybrid Transmission (DHT) system is a hybrid system, see Figure 1 , Figure 1 It is a schematic diagram of the structure of a DHT system. The engine 1 is connected to the planet carrier 4 of the P1 planetary gearbox, the generator 2 is connected to the sun gear 5 of the P1 planetary gearbox, the ring gear 3 of the P1 planetary gearbox outputs power and is connected to the drive motor 6 and the input shaft 7 of the gearbox, and the output shaft 9 of the gearbox is connected to the wheel end.

[0052] For hybrid vehicles that use a partial hybrid power system (such as a DHT system), during the engine shutdown process, the relevant technology cuts off the power transmission between the input shaft and the output shaft by sending an interrupt command, thereby preventing the torque generated by the change in engine speed during the shutdown process from being transmitted to the wheel end connected to the output shaft, thereby reducing body vibration. However, this method can only be applied to the engine shutdown process when the vehicle is stationary, and cannot be applied to the engine shutdown process when the vehicle is driving, that is, including the condition where the engine's multi-power source mode switches to a single power source mode driven by a drive motor. There are fewer applicable conditions.

[0053] Based on this, the embodiment of the present application provides an engine shutdown control method and related devices. In response to obtaining a shutdown instruction, the input shaft torque of the vehicle is reduced. If the input shaft torque is reduced to a torque safety threshold, an interrupt request is sent to disconnect the power transmission between the input shaft and the output shaft to prevent the torque generated by the engine speed fluctuation during the engine shutdown process from being transmitted to the wheel end, thereby suppressing vibration. If the power transmission between the input shaft and the output shaft is disconnected, a speed matching request is sent, and the speed of the drive motor is adjusted according to the speed matching condition indicated by the speed matching request, so that the vehicle can be applied to not only the vehicle static working condition but also the driving working condition. In the mode switching process, that is, in the process of switching from the multi-power source mode including the engine to the single power source mode of the drive single machine drive, the speed between the drive motor and the output shaft can be matched, reducing the vibration caused by the speed mismatch.

[0054] The engine shutdown control method provided in the present application can be applied to a hybrid electric vehicle with engine shutdown control capability, wherein the hybrid electric vehicle may include an engine, a vehicle controller, a drive motor, a generator, etc.

[0055] See also Figure 2 , Figure 2 The following is a flow chart of the engine shutdown control method provided in the embodiment of the present application. For the convenience of description, the following embodiment is introduced by taking the execution subject of the engine shutdown control method as the vehicle controller as an example. Figure 2 As shown, the method includes S201-S204.

[0056] S201: In response to obtaining a stop instruction, reducing the input shaft torque of the vehicle.

[0057] The shutdown command is a signal sent by the vehicle controller to instruct the engine to shut down. When the hybrid vehicle switches from a multi-power source mode including the engine to a single power source mode driven by the drive motor, a shutdown command will be sent. For example, when the vehicle is driving at a low speed, the power demand can be met by driving only the drive motor. At this time, the engine providing power can be shut down; for another example, when the vehicle is driving on a congested road in the city and starts and stops frequently, the engine providing power can be shut down to reduce fuel consumption.

[0058] The input shaft torque is the total torque of the various power sources of the hybrid vehicle acting on the input shaft of the gearbox, including the torque of the engine and the torque of the drive motor. When the hybrid vehicle includes a generator and the generator is one of the power sources, the input shaft torque also includes the torque of the generator.

[0059] When a shutdown command is obtained, in order to make the power connection between the input shaft and the output shaft disconnected more smoothly, it is necessary to reduce the torque of each power source of the vehicle on the input shaft. Specifically, after the vehicle controller receives the shutdown command through the controller area network (CAN) bus, it can send a command to the engine management system to gradually reduce the injection amount and ignition advance angle to reduce the torque of the engine on the input shaft. Send a command to reduce the current of the drive motor to the drive motor controller to reduce the torque of the drive motor on the input shaft.

[0060] S202: If the input shaft torque drops to the torque safety threshold, an interrupt request is sent.

[0061] Different hybrid vehicles use various hybrid systems. For example, some hybrid vehicles use a parallel hybrid system (Parallel Hybrid System Type 2, P2). The P2 system usually includes a clutch, while some hybrid vehicles use a DHT system that does not include a clutch. An interrupt request is a signal sent by the vehicle controller to disconnect the power transmission between the input shaft and the output shaft. For example, an interrupt request may include a clutch disconnect request and a neutral shift request. The clutch disconnect request is a request to indicate that the clutch is disconnected, and the neutral shift request is a request to indicate that the transmission is switched from the initial gear to the neutral gear. Both requests can disconnect the power transmission between the input shaft and the output shaft.

[0062] As an implementation manner, in a hybrid vehicle that does not include a clutch (eg, a hybrid vehicle that uses a DHT system), the power transmission between the input shaft and the output shaft may be disconnected by sending a neutral shift request.

[0063] The torque safety threshold is a preset critical value used to determine whether the input shaft torque has dropped to a sufficiently low level. The torque safety threshold is usually set based on the design parameters and safety requirements of the hybrid system to ensure that the input shaft torque has reached the preset safety range when the power transmission is disconnected. For example, the torque safety threshold is 5 Newton meters (Nm). When the input shaft torque drops to 5Nm or lower, the power transmission between the input shaft and the output shaft can be safely and smoothly disconnected, and an interrupt request is sent. As an implementation method, if the input shaft torque is equal to 0Nm, an interrupt request is sent.

[0064] When the input shaft torque is in a high torque state (greater than the torque safety threshold), if an interrupt request is sent directly to disconnect the power transmission between the input shaft and the output shaft, it will cause greater shock and vibration to the vehicle body, and will also cause instability in the hybrid system and increase wear on mechanical components.

[0065] Therefore, when the input shaft torque is less than or equal to the torque safety threshold, sending an interrupt request can not only reduce the impact and vibration of the vehicle body, but also reduce the wear of mechanical components and extend the service life of the vehicle.

[0066] S203: If the power transmission between the input shaft and the output shaft is disconnected, a speed matching request is sent.

[0067] Among them, the speed matching request is used to indicate that the speed of the drive motor is matched with the speed of the output shaft. The speed matching condition indicated by the speed matching request is that the speed of the drive motor matches the speed of the output shaft. Among them, due to the transmission ratio, the transmission ratio conversion is required in the process of converting the output shaft speed to the speed of the input shaft. After conversion, if the difference between the speed of the drive motor and the converted output shaft speed is less than the preset threshold, the speed matching condition is met.

[0068] After the power transmission between the input shaft and the output shaft is disconnected, if the hybrid system is a DHT system, the engine speed can be adjusted to 0 revolutions per minute (r / min) through the generator (Integrated Starter Generator, ISG)

[0069] For example, after sending a speed matching request, the output shaft speed is 800r / min. After transmission ratio conversion, the speed of the drive motor needs to reach 1800r / min. The preset threshold is 50r / min, and the speed matching condition is that the speed of the drive motor reaches 1750r / min-1850r / min.

[0070] As an implementation method, if the interruption request is a request to switch to neutral, it can be determined whether the power transmission between the input shaft and the output shaft is disconnected based on whether the gear is switched to neutral. Correspondingly, the speed matching request is a request to shift back.

[0071] S204: Adjusting the speed of the driving motor according to the speed matching condition indicated by the speed matching request.

[0072] When the speed of the drive motor reaches the speed matching condition, the speed matching is completed, so that the car can switch from a multi-power source including the engine to a single power source mode driven by the drive motor during driving. Since the speed of the drive motor matches the speed of the output shaft, the impact and vibration on the wheel end caused by the speed mismatch is reduced.

[0073] In response to obtaining a shutdown command, the input shaft torque of the vehicle is reduced. If the input shaft torque is reduced to a torque safety threshold, an interrupt request is sent to disconnect the power transmission between the input shaft and the output shaft to prevent the torque generated by the engine speed fluctuation during the engine shutdown process from being transmitted to the wheel end, thereby suppressing vibration. If the power transmission between the input shaft and the output shaft is disconnected, a speed matching request is sent, and the speed of the drive motor is adjusted according to the speed matching condition indicated by the speed matching request, so that the vehicle can be suitable for not only the vehicle static working condition but also the driving working condition. In the process of mode switching, that is, in the process of switching from the multi-power source mode including the engine to the single power source mode of the drive single machine drive, the speed between the drive motor and the output shaft can be matched, thereby reducing the vibration caused by the speed mismatch.

[0074] If speed adjustment after sending a speed matching request may cause the mode switching time to be too long, the embodiment of the present application provides a specific implementation method for adjusting the speed of the drive motor in advance, see A1-A3:

[0075] A1: After the power transmission between the input shaft and the output shaft is disconnected and before the speed matching request is sent, the current vehicle speed is obtained.

[0076] The current vehicle speed is the speed at which the vehicle is currently traveling.

[0077] A2: Determine the target speed of the drive motor according to the current vehicle speed.

[0078] The target speed is the adjustment target value of the speed of the drive motor. The target speed corresponding to the current vehicle speed can be determined based on the correspondence between the vehicle speed and the speed. The target speed is used to indicate the speed at which the drive motor reaches the speed matching condition.

[0079] As an implementation method, the target speed may be adjusted in real time by obtaining the current vehicle speed in real time.

[0080] A3: Control the drive motor to adjust the speed of the drive motor in the direction of the target speed.

[0081] By adjusting the speed of the drive motor immediately after the power transmission between the input shaft and the output shaft is disconnected, the difference between the speed of the drive motor and the target speed can be narrowed before the speed matching request is sent, so that the speed matching condition can be reached more quickly after the speed matching request is sent, thereby shortening the time used for mode switching.

[0082] In order to adjust the speed of the drive motor to reach the target speed more quickly, the embodiment of the present application further provides a specific implementation method of adjusting the speed of the drive motor based on the speed change rate, see B1-B3:

[0083] B1: Get the current speed of the drive motor.

[0084] B2: Determine the target speed change rate based on the difference between the current speed and the target speed.

[0085] Among them, the target speed change rate is the speed value of the driving motor that changes per unit time, which is used to indicate the speed of the driving motor. The greater the difference between the current speed and the target speed, the greater the target speed change rate, and the faster the speed adjustment of the driving motor.

[0086] For example, the current speed is 1000r / min and the target speed is 2000r / min, and the difference between them is 1000r / min. The target speed change rate can be determined to be 1000rpm / s. If the current speed is 200r / min and the target speed is 2000r / min, and the difference between them is 1800r / min, the target speed change rate can be determined to be 2000rpm / s.

[0087] B3: Control the drive motor to adjust the speed of the drive motor in the direction of the target speed according to the target speed change rate.

[0088] Therefore, when the current rotation speed differs greatly from the target rotation speed, a larger target rotation speed change rate can be determined, thereby making the drive motor reach the target rotation speed more quickly and shortening the mode switching time.

[0089] In order to more accurately control the speed adjustment process of the drive motor, the embodiment of the present application also provides a specific implementation method for dynamically adjusting the target speed change rate, see C1-C2:

[0090] C1: Determine the (i+1)th target speed change rate based on the i-th difference between the target speed and the i-th current speed.

[0091] Among them, since the control signal sending process is discrete, the speed adjustment process of the drive motor usually includes multiple times, the i-th time is a time from when the power transmission between the input shaft and the output shaft is disconnected to when the speed of the drive motor reaches the target speed, and there is a control cycle between the i-th time and the i+1-th time, i is a positive integer, the larger the i-th difference, the larger the target speed change rate of the i+1-th time, the faster the speed adjustment of the drive motor for the i+1-th time, the smaller the i-th difference, the smaller the target speed change rate of the i+1-th time, and the slower the speed adjustment of the drive motor for the i+1-th time.

[0092] When the i-th difference is larger, the difference should be compensated with a faster adjustment speed (target speed change rate). When the i-th difference is smaller, if an excessively large adjustment speed is still used, due to the difference in the control accuracy of the drive motor (for example, different control cycles), when the drive motor is close to reaching the target speed, due to the excessive speed change step, the speed may exceed the target speed too much, and the target speed may not be reached, resulting in a longer process to reach the speed matching condition. Therefore, through C1, as the i-th difference continues to decrease, the target speed change rate of the i+1th time also gradually decreases, and the speed change step is continuously shortened.

[0093] C2: At the i+1th time, the speed of the drive motor is controlled to adjust toward the target speed according to the i+1th target speed change rate.

[0094] As a result, the speed change curve of the drive motor changes from rapid to slow, thereby reducing the speed change step before reaching the target speed. Under the premise of ensuring that the target speed is reached quickly, the speed of the drive motor can be adjusted more accurately.

[0095] The embodiment of the present application provides a speed adjustment method applied to a DHT system, wherein the interrupt request is a neutral gear switching request, the speed matching request is a backshift request, the neutral gear switching request is used to indicate switching the initial gear to the neutral gear, and the backshift request is used to indicate switching the neutral gear to the target gear, see D1-D4:

[0096] D1: After the initial gear is switched to neutral and before a shift back request is sent, the current vehicle speed and the conversion relationship between the vehicle speed and the gear are obtained.

[0097] The conversion relationship is suitable for converting the vehicle speed into a gear position. The current vehicle speed can be converted into a corresponding target gear position through the conversion relationship. The target gear position is the gear position that the shift back request indicates is switched from neutral gear.

[0098] D2: Determine the target gear corresponding to the current vehicle speed based on the conversion relationship.

[0099] As an implementation method, since adjacent gears have overlapping vehicle speed ranges, the target gear can also be determined based on the initial gear and the current vehicle speed, making the target gear more accurate.

[0100] D3: Determine the target speed based on the target gear.

[0101] The target speed can be determined not only directly by the current vehicle speed, but also by the target gear position converted from the current vehicle speed.

[0102] D4: Control the drive motor to adjust the speed of the drive motor in the direction of the target speed.

[0103] Therefore, in the DHT system, the power transmission between the input shaft and the output shaft is interrupted by switching the neutral gear request, the mode switch is completed by the back gear request, and the speed of the drive motor is adjusted in advance before the mode switch, thereby shortening the mode switch time.

[0104] See also Figure 3 , Figure 3 An engine shutdown control device provided in an embodiment of the present application, the device 300 includes: an acquisition unit 301, a sending unit 302 and a control unit 303;

[0105] The acquisition unit 301 is used to reduce the input shaft torque of the vehicle in response to acquiring the shutdown instruction, where the input shaft torque includes the torque of the engine and the torque of the drive motor;

[0106] The sending unit 302 is used to send an interrupt request if the input shaft torque is reduced to a torque safety threshold, wherein the interrupt request is used to disconnect the power transmission between the input shaft and the output shaft;

[0107] The sending unit 302 is further configured to send a speed matching request if the power transmission between the input shaft and the output shaft is disconnected, wherein the speed matching request is used to instruct to match the speed of the drive motor with the speed of the output shaft;

[0108] The control unit 303 is used to adjust the speed of the driving motor according to the speed matching condition indicated by the speed matching request.

[0109] It can be seen from the above technical scheme that the engine shutdown control device provided in the embodiment of the present application includes an acquisition unit, a sending unit and a control unit. The acquisition unit responds to the acquisition of the shutdown command to reduce the input shaft torque of the vehicle. If the input shaft torque is reduced to the torque safety threshold, the sending unit sends an interrupt request to disconnect the power transmission between the input shaft and the output shaft to prevent the torque generated by the engine speed fluctuation during the engine shutdown process from being transmitted to the wheel end, thereby suppressing vibration. If the power transmission between the input shaft and the output shaft is disconnected, the sending unit sends a speed matching request, and the speed unit adjusts the speed of the drive motor according to the speed matching condition indicated by the speed matching request, so that the vehicle can be applied not only to the vehicle static working condition but also to the driving working condition. In the mode switching process, that is, in the process of switching from the multi-power source mode of the engine to the single power source mode of the drive single machine drive, the speed between the drive motor and the output shaft can be matched, reducing the vibration caused by the speed mismatch.

[0110] As a possible implementation, the device further includes a vehicle speed unit, a first determination unit and a speed regulation unit:

[0111] The vehicle speed unit is used to obtain the current vehicle speed after the power transmission between the input shaft and the output shaft is disconnected and before sending the speed matching request;

[0112] The first determination unit is used to determine the target speed of the drive motor according to the current vehicle speed;

[0113] The speed regulating unit is used to control the driving motor to adjust the speed of the driving motor toward the target speed.

[0114] As a possible implementation, the speed regulating unit is specifically used for:

[0115] Obtaining the current speed of the driving motor;

[0116] Determine a target speed change rate according to a difference between the current speed and the target speed, wherein the target speed change rate is used to indicate how fast the speed of the drive motor changes. The greater the difference, the greater the target speed change rate, and the faster the speed of the drive motor is adjusted;

[0117] The driving motor is controlled to adjust the speed of the driving motor toward the target speed according to the target speed change rate.

[0118] As a possible implementation, the speed regulating unit is specifically used for:

[0119] Determine the i+1th target speed change rate according to the i-th difference between the target speed and the i-th current speed, wherein the greater the i-th difference, the greater the i+1th target speed change rate, and the faster the speed adjustment of the i+1th drive motor;

[0120] The step of controlling the driving motor to adjust the speed of the driving motor in the direction of the target speed according to the target speed change rate includes:

[0121] At the (i+1)th time, the speed of the drive motor is controlled to be adjusted toward the target speed according to the (i+1)th target speed change rate.

[0122] As a possible implementation, the device further includes a conversion unit, a second determination unit, a third determination unit and a gear shifting and speed regulating unit:

[0123] The conversion unit is used to obtain the current vehicle speed and the conversion relationship between the vehicle speed and the gear position after the initial gear position is switched to the neutral gear and before sending the shift back request;

[0124] The second determining unit is used to determine the target gear corresponding to the current vehicle speed according to the conversion relationship;

[0125] The third determining unit is used to determine a target speed according to the target gear position;

[0126] The gear shifting and speed regulating unit is used to control the driving motor to adjust the speed of the driving motor toward the target speed.

[0127] See also Figure 4 , the embodiment of the present application further provides a vehicle, the vehicle comprising a memory 401 and a processor 402:

[0128] The memory is used to store a computer program and transmit the computer program to the processor;

[0129] The processor is configured to execute the method of the above method embodiment according to the computer program.

[0130] An embodiment of the present application further provides a computer-readable storage medium, characterized in that the computer-readable storage medium is used to store a computer program, and the computer program is used to execute the method of the above method embodiment.

[0131] The embodiment of the present application also provides a computer program product including a computer program, which, when executed on a computer device, enables the computer device to execute the method of the above method embodiment.

[0132] See also Figure 5 , Figure 5 A flow chart of an engine shutdown control method provided in an embodiment of the present application, which is applied to a DHT system. When a shutdown command is obtained, the input shaft torque is reduced. If the input shaft torque is 0 Nm, a request to clear the gear (switching to neutral request) is sent. After the gear is cleared (after the gear is switched to neutral, that is, after the power transmission between the input shaft and the output shaft is disconnected), the speed of the TM motor (drive motor) is immediately adjusted to reach the target speed. The target speed is determined by the target gear corresponding to the current vehicle speed. When the speed adjustment is completed (speed matching), the gear is returned to the target gear.

[0133] It should be noted that the various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments, and the same or similar parts between the various embodiments can be referred to each other. For the system or device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part description.

[0134] The term "including" and its variations used herein are open inclusions, i.e., "including but not limited to". The term "based on" means "based at least in part on". The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment"; the term "some embodiments" means "at least some embodiments". The relevant definitions of other terms will be given in the following description.

[0135] It should be understood that in the present application, "at least one (item)" means one or more, and "plurality" means two or more. "And / or" is used to describe the association relationship of associated objects, indicating that three relationships may exist. For example, "A and / or B" can mean: only A exists, only B exists, and A and B exist at the same time, where A and B can be singular or plural. The character " / " generally indicates that the objects associated before and after are in an "or" relationship. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single or plural items. For example, at least one of a, b or c can mean: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, c can be single or multiple.

[0136] It should also be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0137] The steps of the method or algorithm described in conjunction with the embodiments disclosed herein may be implemented directly using hardware, a software module executed by a processor, or a combination of the two. The software module may be placed in a random access memory (RAM), a memory, a read-only memory (ROM), an electrically programmable ROM, an electrically erasable programmable ROM, a register, a hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art.

[0138] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An engine shutdown control method, characterized in that: Applied to a hybrid vehicle, the method comprises: In response to obtaining a stop command, reducing an input shaft torque of the vehicle, the input shaft torque including a torque of an engine and a torque of a drive motor; If the input shaft torque drops to a torque safety threshold, an interrupt request is sent, wherein the interrupt request is used to disconnect the power transmission between the input shaft and the output shaft; If the power transmission between the input shaft and the output shaft is disconnected, a speed matching request is sent, wherein the speed matching request is used to instruct to match the speed of the drive motor with the speed of the output shaft; The speed of the driving motor is adjusted according to the speed matching condition indicated by the speed matching request.

2. The method according to claim 1, characterized in that The method further comprises: After the power transmission between the input shaft and the output shaft is disconnected and before sending a speed matching request, obtaining a current vehicle speed; determining a target speed of the drive motor according to the current vehicle speed; The driving motor is controlled to adjust the rotation speed of the driving motor toward the target rotation speed.

3. The method according to claim 2, characterized in that The controlling the driving motor to adjust the speed of the driving motor toward the target speed includes: Obtaining the current speed of the driving motor; Determine a target speed change rate according to a difference between the current speed and the target speed, wherein the target speed change rate is used to indicate how fast the speed of the drive motor changes. The greater the difference, the greater the target speed change rate, and the faster the speed of the drive motor is adjusted; The driving motor is controlled to adjust the speed of the driving motor toward the target speed according to the target speed change rate.

4. The method according to claim 3, characterized in that If the current speed includes the i-th current speed, the i-th time is a time from when the power transmission between the input shaft and the output shaft is disconnected to when the speed of the drive motor reaches the target speed, and i is a positive integer, the target speed change rate is determined according to the difference between the current speed and the target speed, including: Determine the i+1th target speed change rate according to the i-th difference between the target speed and the i-th current speed, wherein the greater the i-th difference, the greater the i+1th target speed change rate, and the faster the speed adjustment of the i+1th drive motor; The step of controlling the driving motor to adjust the speed of the driving motor in the direction of the target speed according to the target speed change rate includes: At the (i+1)th time, the speed of the drive motor is controlled to be adjusted toward the target speed according to the (i+1)th target speed change rate.

5. The method according to claim 1, characterized in that If the interrupt request is a neutral gear switching request, the speed matching request is a backshift request, the neutral gear switching request is used to instruct to switch the initial gear to the neutral gear, and the backshift request is used to instruct to switch the neutral gear to the target gear, the method further includes: After the initial gear is switched to the neutral gear and before a shift back request is sent, obtaining a current vehicle speed and a conversion relationship between the vehicle speed and the gear; Determining the target gear corresponding to the current vehicle speed according to the conversion relationship; determining a target speed according to the target gear position; The driving motor is controlled to adjust the rotation speed of the driving motor toward the target rotation speed.

6. An engine shutdown control device, characterized in that: The device comprises: an acquisition unit, a sending unit and a control unit; The acquisition unit is used to reduce the input shaft torque of the vehicle in response to acquiring the shutdown instruction, wherein the input shaft torque includes the torque of the engine and the torque of the drive motor; The sending unit is used to send an interrupt request if the input shaft torque decreases to a torque safety threshold, wherein the interrupt request is used to disconnect the power transmission between the input shaft and the output shaft; The sending unit is further used to send a speed matching request if the power transmission between the input shaft and the output shaft is disconnected, wherein the speed matching request is used to instruct to match the speed of the drive motor with the speed of the output shaft; The control unit is used to adjust the speed of the drive motor according to the speed matching condition indicated by the speed matching request.

7. The device according to claim 6, characterized in that The device also includes a vehicle speed unit, a first determination unit and a speed regulation unit: The vehicle speed unit is used to obtain the current vehicle speed after the power transmission between the input shaft and the output shaft is disconnected and before sending the speed matching request; The first determination unit is used to determine the target speed of the drive motor according to the current vehicle speed; The speed regulating unit is used to control the driving motor to adjust the speed of the driving motor toward the target speed.

8. A vehicle, characterized in that: The vehicle comprises a processor and a memory: The memory is used to store a computer program and transmit the computer program to the processor; The processor is configured to execute the method according to any one of claims 1 to 6 according to the computer program.

9. A computer-readable storage medium, characterized in that: The computer-readable storage medium is used to store a computer program, and the computer program is used to execute the method according to any one of claims 1 to 6.

10. A computer program product comprising a computer program, characterized in that When the method is executed on a computer device, the computer device is enabled to execute the method according to any one of claims 1 to 6.

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