Vehicle mode switching method and system and vehicle

Abstract

The invention provides a vehicle mode switching method and system and a vehicle, and belongs to the technical field of vehicle control. According to the embodiment of the invention, when the vehicle is in a direct-drive mode, whether the vehicle meets the mode switching condition of switching from the direct-drive mode to a power dividing mode or not can be accurately judged by recognizing the working condition information of the vehicle, and the switching efficiency is improved. And when it is determined that the vehicle meets the mode switching condition, the clutch can be kept in the closed state, torque adjustment is conducted on the engine and the first motor, and therefore when the first synchronizer meets the gear switching condition, the first synchronizer can be controlled to be switched to the power split gear from the combined gear. According to the embodiment of the invention, intelligent switching of the vehicle from the direct drive mode to the power dividing mode can be realized, and the gear shifting operation of the first synchronizer can be completed on the premise that the clutch is not opened or closed, so that the mode switching time is effectively shortened while the charging requirement of the power battery is met, and the vehicle safety is improved. And the dynamic response performance of the vehicle in the mode switching process is improved.

Description

Technical Field

[0001] The present application relates to the technical field of vehicle control, and particularly to a vehicle mode switching method, system, and vehicle. Background Art

[0002] With the rapid development of the automotive industry and in response to the national policies on energy conservation, emission reduction, and carbon balance, traditional fuel vehicles are gradually moving towards hybrid vehicles. To adapt to different road conditions and driving requirements, hybrid vehicles usually have multiple driving modes including a direct drive mode and a power split mode. During vehicle driving, the driving modes will switch to each other under certain conditions.

[0003] In the related art, during the process of the vehicle switching from the direct drive mode to the power split mode, it is usually necessary to first open the clutch, then perform a torque reduction operation on the engine, and then re - close the clutch after the torque reduction operation is completed to complete the mode switching. However, due to the process of opening and closing the clutch, this method has problems such as a long mode switching time and untimely engine power response, which further affects the power response performance of the vehicle during mode switching. Summary of the Invention

[0004] The present application provides a vehicle mode switching method, device, system, and vehicle to solve the problem of poor overall vehicle power response performance when a hybrid vehicle switches from the direct drive mode to the power split mode.

[0005] To solve the above problems, the present application adopts the following technical solutions:

[0006] In a first aspect, an embodiment of the present application provides a vehicle mode switching method. The vehicle includes an engine, a clutch, a first motor, and a transmission; the transmission includes a power split mechanism, a first synchronizer, and a transmission input shaft. The engine is connected to a first input end of the power split mechanism through the clutch, the first motor is connected to a second input end of the power split mechanism, an output end of the power split mechanism is connected to the transmission input shaft, and the first synchronizer is disposed between the first input end and the output end; the method includes:

[0007] When the vehicle is in the direct drive mode, based on the vehicle's operating condition information, determine whether the vehicle meets the mode switching condition for switching from the direct drive mode to the power split mode;

[0008] When it is determined that the vehicle meets the mode switching condition, keep the clutch in a closed state, and perform torque adjustment on the engine and the first motor to make the first synchronizer meet the gear shifting condition;

[0009] When the first synchronizer meets the gear shifting condition, control the first synchronizer to shift from the engaged gear to the power split gear, so that the vehicle switches from the direct drive mode to the power split mode.

[0010] In an embodiment of the present application, the operating condition information includes road condition information and the current remaining power of the power battery.

[0011] The step of determining whether the vehicle meets the mode switching condition for switching from the direct drive mode to the power split mode based on the operating condition information of the vehicle includes:

[0012] When the current remaining power is less than the power threshold, determine the current road condition of the vehicle based on the road condition information.

[0013] When the current road condition is a preset road condition, determine that the vehicle meets the mode switching condition for switching from the direct drive mode to the power split mode.

[0014] In an embodiment of the present application, the step of adjusting the torque of the engine and the first motor includes:

[0015] When the current motor torque of the first motor is a negative torque, keep the current motor torque unchanged, and adjust the torque of the engine based on the current motor torque.

[0016] When the current motor torque of the first motor is a positive torque, control the current engine torque of the engine and the current motor torque of the first motor to follow a preset target torque.

[0017] In an embodiment of the present application, the power split mechanism includes a ring gear, a sun gear, a plurality of planet gears meshing between the ring gear and the sun gear, and a planet carrier rotatably connected to the plurality of planet gears; the planet carrier is connected to the engine as the first input end, the sun gear is connected to the first motor as the second input end, the ring gear is connected to the transmission input shaft as the output end, and the first synchronizer is arranged between the planet carrier and the ring gear.

[0018] The step of adjusting the torque of the engine based on the current motor torque includes:

[0019] When the current gear position of the first synchronizer is the engaged gear, determine that the transmission ratio between the sun gear and the planet carrier is the first transmission ratio.

[0020] Based on the current motor torque of the first motor and the first transmission ratio, determine the target engine torque of the engine.

[0021] Based on a preset torque adjustment gradient, control the current engine torque of the engine to gradually decrease to the target engine torque.

[0022] In an embodiment of the present application, the steps of controlling the current engine torque of the engine and the current motor torque of the first motor to follow a preset target torque include:

[0023] Based on a preset torque adjustment gradient, control the current engine torque of the engine and the current motor torque of the first motor to gradually decrease to the target torque.

[0024] In an embodiment of the present application, the vehicle further includes a second motor, and the method further includes:

[0025] Determine the compensation torque of the second motor based on the current engine torque and the current motor torque;

[0026] Determine the target drive torque of the second motor based on the compensation torque and the current drive torque of the second motor;

[0027] During the process of adjusting the torques of the engine and the first motor, based on a preset torque adjustment gradient, control the second motor to gradually increase from the current drive torque to the target drive torque.

[0028] In an embodiment of the present application, after the step of adjusting the torque of the engine based on the current motor torque, the method further includes:

[0029] When the first torque difference between the current engine torque of the engine and the target engine torque is less than a first torque threshold, trigger timing for a first duration during which the first torque difference is less than the first torque threshold;

[0030] When the first duration is greater than a first duration threshold, determine that the first synchronizer meets the gear shifting condition.

[0031] In an embodiment of the present application, after the step of controlling the current engine torque of the engine and the current motor torque of the first motor to follow a preset target torque, the method further includes:

[0032] When the second torque difference between the current engine torque of the engine and the target torque is less than a second torque threshold, trigger timing for a second duration during which the second torque difference is less than the second torque threshold;

[0033] When a third torque difference between a current motor torque of the first motor and the target torque is less than a third torque threshold, start timing for a third duration during which the third torque difference is less than the third torque threshold.

[0034] When the second duration is greater than a second duration threshold and the third duration is greater than a third duration threshold, determine that the first synchronizer meets the gear shifting condition.

[0035] Second, based on the same inventive concept, an embodiment of the present application provides a vehicle mode switching device. The vehicle includes an engine, a clutch, a first motor, and a transmission. The transmission includes a power splitting mechanism, a first synchronizer, and a transmission input shaft. The engine is connected to a first input end of the power splitting mechanism through the clutch. The first motor is connected to a second input end of the power splitting mechanism. An output end of the power splitting mechanism is connected to the transmission input shaft. The first synchronizer is arranged between the first input end and the output end. The device includes:

[0036] A condition determining module, configured to determine, when the vehicle is in a direct drive mode, whether the vehicle meets a mode switching condition for switching from the direct drive mode to a power splitting mode based on the operating condition information of the vehicle.

[0037] A torque adjusting module, configured to, when it is determined that the vehicle meets the mode switching condition, keep the clutch in a closed state and adjust torques of the engine and the first motor so that the first synchronizer meets the gear shifting condition.

[0038] A gear shifting module, configured to, when the first synchronizer meets the gear shifting condition, control the first synchronizer to switch from an engaged gear to a power splitting gear so that the vehicle switches from the direct drive mode to the power splitting mode.

[0039] In an embodiment of the present application, the operating condition information includes road condition information and a current remaining power of a power battery. The condition determining module includes:

[0040] A road condition determining sub-module, configured to determine a current road condition of the vehicle based on the road condition information when the current remaining power is less than a power threshold.

[0041] A condition determining sub-module, configured to determine that the vehicle meets the mode switching condition for switching from the direct drive mode to the power splitting mode when the current road condition is a preset road condition.

[0042] In an embodiment of the present application, the torque adjusting module includes:

[0043] The first torque adjustment sub-module is configured to keep the current motor torque unchanged when the current motor torque of the first motor is a negative torque, and adjust the torque of the engine based on the current motor torque.

[0044] The second torque adjustment sub-module is configured to control the current engine torque of the engine and the current motor torque of the first motor to follow a preset target torque when the current motor torque of the first motor is a positive torque.

[0045] In an embodiment of the present application, the power split mechanism includes a ring gear, a sun gear, a plurality of planet gears meshing between the ring gear and the sun gear, and a planet carrier rotatably connected to the plurality of planet gears; the planet carrier is connected to the engine as the first input end, the sun gear is connected to the first motor as the second input end, the ring gear is connected to the transmission input shaft as the output end, and the first synchronizer is disposed between the planet carrier and the ring gear; the first torque adjustment sub-module includes:

[0046] A gear ratio determination unit is configured to determine that the gear ratio between the sun gear and the planet carrier is a first gear ratio when the current gear position of the first synchronizer is the engaged gear position.

[0047] An engine torque determination unit is configured to determine the target engine torque of the engine based on the current motor torque of the first motor and the first gear ratio.

[0048] A first torque adjustment unit is configured to control the current engine torque of the engine to gradually decrease to the target engine torque based on a preset torque adjustment gradient.

[0049] In an embodiment of the present application, the second torque adjustment sub-module includes:

[0050] A second torque adjustment unit is configured to control the current engine torque of the engine and the current motor torque of the first motor to gradually decrease to the target torque based on a preset torque adjustment gradient.

[0051] In an embodiment of the present application, the vehicle further includes a second motor, and the vehicle mode switching device further includes:

[0052] A compensation torque determination module is configured to determine the compensation torque of the second motor based on the current engine torque and the current motor torque.

[0053] A driving torque determination module is configured to determine the target driving torque of the second motor based on the compensation torque and the current driving torque of the second motor.

[0054] A driving torque control module, configured to control the second motor to gradually increase from the current driving torque to the target driving torque based on a preset torque adjustment gradient during the process of adjusting the torques of the engine and the first motor.

[0055] In an embodiment of the present application, the vehicle mode switching device further includes:

[0056] A first timing module, configured to trigger timing for a first duration during which the first torque difference between the current engine torque of the engine and the target engine torque is less than a first torque threshold;

[0057] A first switching condition determination module, configured to determine that the first synchronizer meets the gear shifting condition when the first duration is greater than a first duration threshold.

[0058] In an embodiment of the present application, the vehicle mode switching device further includes:

[0059] A second timing module, configured to trigger timing for a second duration during which the second torque difference between the current engine torque of the engine and the target torque is less than a second torque threshold;

[0060] A third timing module, configured to trigger timing for a third duration during which the third torque difference between the current motor torque of the first motor and the target torque is less than a third torque threshold;

[0061] A second switching condition determination module, configured to determine that the first synchronizer meets the gear shifting condition when the second duration is greater than a second duration threshold and the third duration is greater than a third duration threshold.

[0062] In a third aspect, based on the same inventive concept, an embodiment of the present application provides a vehicle mode switching system. The vehicle includes an engine, a clutch, a first motor, and a gearbox. The gearbox includes a power split mechanism, a first synchronizer, and a gearbox input shaft. The engine is connected to a first input end of the power split mechanism through the clutch, the first motor is connected to a second input end of the power split mechanism, an output end of the power split mechanism is connected to the gearbox input shaft, and the first synchronizer is disposed between the first input end and the output end. The system includes a vehicle controller, a gearbox controller, a motor controller, and an engine controller. Among them,

[0063] The vehicle control unit is configured to, when the vehicle is in the direct drive mode, determine whether the vehicle meets the mode switching condition for switching from the direct drive mode to the power split mode based on the vehicle operating condition information, and when it is determined that the vehicle meets the mode switching condition, send a clutch state holding request to the transmission control unit, send an engine torque adjustment request to the engine control unit, and send a motor torque adjustment request to the motor control unit;

[0064] The transmission control unit is configured to keep the clutch in a closed state in response to the clutch state holding request;

[0065] The engine control unit is configured to adjust the torque of the engine in response to the engine torque adjustment request, and the motor control unit is configured to adjust the torque of the first motor in response to the motor torque adjustment request so that the first synchronizer meets the gear shifting condition;

[0066] The vehicle control unit is further configured to send a gear shifting request to the transmission control unit when the first synchronizer meets the gear shifting condition;

[0067] The transmission control unit is further configured to control the first synchronizer to switch from the engaged gear to the power split gear in response to the gear shifting request, so that the vehicle switches from the direct drive mode to the power split mode.

[0068] In a fourth aspect, based on the same inventive concept, an embodiment of the present application provides a vehicle, including the vehicle mode switching system proposed in the third aspect of the present application.

[0069] Compared with the prior art, the present application has the following advantages:

[0070] A vehicle mode switching method provided by an embodiment of the present application, when the vehicle is in a direct drive mode, based on the operating conditions information of the vehicle, determines whether the vehicle meets the mode switching conditions for switching from the direct drive mode to the power split mode. When it is determined that the vehicle meets the mode switching conditions, the clutch is kept in a closed state, and the torque of the engine and the first motor is adjusted, so that when the first synchronizer meets the gear shifting conditions, the first synchronizer can be controlled to switch from the engaged gear to the power split gear, so that the vehicle switches from the direct drive mode to the power split mode. By identifying the operating conditions information of the vehicle, the embodiment of the present application can control the vehicle to automatically switch from the direct drive mode to the power split mode. At the same time, by adjusting the torque of the engine and the first motor, the shifting operation of the first synchronizer can be successfully completed without opening or closing the clutch. In this way, the vehicle can switch from the direct drive mode to the power split mode more quickly and smoothly, while meeting the charging requirements of the power battery, effectively shortening the mode switching duration, enabling the engine to quickly output torque, and thus effectively improving the power response performance of the vehicle during the mode switching process. BRIEF DESCRIPTION OF THE DRAWINGS

[0071] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0072] Figure 1 It is a schematic structural diagram of a hybrid vehicle in an embodiment of the present application.

[0073] Figure 2 It is a flowchart of the steps of a vehicle mode switching method in an embodiment of the present application.

[0074] Figure 3 It is a schematic diagram of the functional modules of a vehicle mode switching device in an embodiment of the present application.

[0075] Figure 4 It is a schematic structural diagram of a vehicle mode switching system in an embodiment of the present application.

[0076] Figure 5 It is a schematic structural diagram of a vehicle in an embodiment of the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0077] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0078] Referring to Figure 1 , a schematic structural diagram of a hybrid vehicle in an embodiment of the present application is shown. The hybrid vehicle is provided with an engine 101, a clutch 102, a first motor 103 and a gearbox on the front axle of the vehicle; the gearbox includes a power split mechanism 104, a gearbox input shaft 107, a gearbox output shaft 108, a first synchronizer 105 and a second synchronizer 106. The engine 101 is connected to the first input end of the power split mechanism 104 through the clutch 102, the first motor 103 is connected to the second input end of the power split mechanism 104, and the output end of the power split mechanism 104 is connected to the gearbox input shaft 107.

[0079] The first synchronizer 105 is arranged between the first input end and the output end and is used to engage or disengage the first input end and the output end. Specifically, when the first synchronizer 105 is in the engaged gear, the first synchronizer 105 is used to engage the first input end and the output end; when the first synchronizer 105 is in the power split gear, the first synchronizer 105 is used to disengage the first input end and the output end. It should be noted that the first synchronizer 105 is used to control the vehicle to switch between the power split mode and other modes, that is, when the first synchronizer 105 is in the power split gear, the vehicle can be in the power split mode; when the first synchronizer 105 is in the engaged gear, the vehicle can be in other modes outside the power split mode, such as the direct drive mode, the series mode or the pure electric four-wheel drive mode, etc.

[0080] The second synchronizer 106 is arranged between the gearbox input shaft 107 and the gearbox output shaft 108 and is used to engage or disengage the gearbox input shaft 107 and the gearbox output shaft 108. Specifically, when the second synchronizer 106 is in gear, the second synchronizer 106 is used to engage the gearbox input shaft 107 and the gearbox output shaft 108; when the second synchronizer 106 is in neutral, the second synchronizer 106 is used to disengage the gearbox input shaft 107 and the gearbox output shaft 108.

[0081] Further, the gearbox output shaft 108 is also connected to the front axle wheels through a front axle differential 109 and is used to transmit power to the front axle wheels through the front axle differential 109 to drive the front axle of the vehicle; the hybrid vehicle is also provided with a second motor (not shown in the figure) on the rear axle of the vehicle, and the second motor is used to transmit power to the rear axle wheels through a rear axle differential (not shown in the figure) to drive the rear axle of the vehicle.

[0082] Since the hybrid vehicle adopting the above architecture is equipped with a power split mechanism 104, and the power split mechanism 104 is simultaneously connected to the engine 101, the first motor 103 and the transmission input shaft 107, the vehicle can have multiple driving modes including a direct drive mode and a power split mode. Furthermore, by changing the gear state of the first synchronizer 105, the vehicle can be switched between different driving modes. Specifically:

[0083] In the power split mode, the first synchronizer 105 is in the power split gear position. At this time, the first synchronizer is in the disengaged state, used to disconnect the first input end and the output end. The second synchronizer 106 is in the engaged state, the engine 101 is in the driving state, the clutch 102 is in the closed state, the first motor 103 is in the power generation state, and the second motor is in the driving state. At this time, the driving force output by the engine 101 is transmitted to the power split mechanism 104 through the clutch 102 and the first input end. The power split mechanism 104 then transmits a part of the driving force to the first motor 103 through the second input end to drive the first motor 103 to generate electricity (at this time, the first motor 103 outputs negative torque), and the generated electric energy is supplied to the power battery for charging. The power split mechanism 104 also transmits another part of the driving force to the transmission input shaft 107 through the output end, and the transmission input shaft 107 sequentially transmits this part of the driving force to the vehicle front axle through the second synchronizer 106, the transmission output shaft 108 and the front axle differential 109 to drive the vehicle to travel. Among them, the distribution ratio of the driving force can be set according to actual needs. That is to say, in the power split mode, a part of the output power of the engine 101 is used to drive the first motor 103 to charge the power battery, and the other part of the output power is used to directly drive the vehicle to travel.

[0084] In the direct drive mode, the first synchronizer 105 is in the engaged gear position, the second synchronizer 106 is in the engaged state, the engine 101 is in the driving state, the clutch 102 is in the closed state, the first motor 103 is usually in the driving state, and the second motor is in the driving state. At this time, the driving force output by the engine 101 will be sequentially transmitted to the transmission input shaft 107 through the first input end of the power split mechanism, the first synchronizer 105 and the output end. The driving force output by the first motor 103 will be transmitted to the transmission input shaft 107 through the second input end and the output end of the power split mechanism, and the transmission input shaft 107 sequentially transmits this part of the driving force to the vehicle front axle through the second synchronizer 106, the transmission output shaft 108 and the front axle differential 109 to drive the vehicle to travel. Since the engine 101 and the first motor 103 can jointly drive the vehicle front axle in the direct drive mode, the overall vehicle driving force in the direct drive mode is usually greater than that in the power split mode.

[0085] It can be seen that when the vehicle switches from the direct drive mode to the power split mode, the first synchronizer 105 needs to be switched from the engaged gear to the power split gear.

[0086] In the related art, during the process of the vehicle switching from the direct drive mode to the power split mode, generally, the vehicle needs to first open the clutch 102, then perform a torque reduction operation on the engine 101. After the torque reduction operation is completed, the clutch 102 also needs to be re-closed to complete the mode switch. However, in this method during the mode switch, the clutch 102 needs to be additionally controlled to open or close. On the one hand, it will also result in a longer switching link and a longer mode switch time. On the other hand, the engine 101 needs to wait for the clutch 102 to be re-closed before it can output torque, resulting in an untimely power response of the engine 101, thereby affecting the overall vehicle power response performance during the mode switch.

[0087] Aiming at the problem of poor overall vehicle power response performance when the current hybrid vehicle switches from the direct drive mode to the power split mode. The present application aims to provide a vehicle mode switching method. By identifying the vehicle's operating condition information, it can control the vehicle to automatically switch from the direct drive mode to the power split mode. At the same time, by adjusting the torques of the engine 101 and the first motor 103, it can smoothly complete the shifting operation of the first synchronizer 105 without opening or closing the clutch 102. In this way, the vehicle can switch from the direct drive mode to the power split mode more quickly and smoothly. While meeting the charging requirements of the power battery, it effectively shortens the mode switch duration, enabling the engine 101 to quickly output torque, thereby effectively improving the power response performance of the vehicle during the mode switch.

[0088] Refer to Figure 2 , which shows a vehicle mode switching method of the present application, applied to a hybrid vehicle adopting the above architecture. The method may include the following steps:

[0089] S201: When the vehicle is in the direct drive mode, based on the vehicle's operating condition information, determine whether the vehicle meets the mode switch condition for switching from the direct drive mode to the power split mode.

[0090] It should be noted that the execution entity of this embodiment can be a computing service device with data processing, network communication, and program running functions, or an electronic device with the above functions such as a vehicle computer, in-vehicle computer, etc., such as an ECU (Electronic Control Unit), BCM (Body Control Module), HCU (Hybrid Control Unit), etc. This embodiment will take the HCU as the execution entity for description. It should be noted that this embodiment does not make specific restrictions on the execution entity of the vehicle.

[0091] In this embodiment, when the vehicle is in the direct drive mode, the HCU will continuously obtain the vehicle's operating condition information, and then based on the operating condition information, determine whether the vehicle needs to switch from the direct drive mode to the power split mode.

[0092] In specific implementation, the operating condition information may include road condition information and the current SOC (State of Charge) of the power battery. The HCU will first determine whether the power battery is in a low power state based on the current SOC. If it is detected that the current remaining power is less than the power threshold, it is determined that the current SOC of the power battery is not sufficient to support the vehicle to operate in the direct drive mode. At this time, the vehicle can switch to the series mode or the power split mode to meet the charging requirements of the power battery. To make the mode switch more accurate, the HCU will further combine the road condition information to determine whether the vehicle needs to switch from the direct drive mode to the power split mode. If it is determined based on the road condition information that the current road condition where the vehicle is located is a preset road condition, it is determined that the vehicle meets the mode switch condition for switching from the direct drive mode to the power split mode.

[0093] In this embodiment, the road condition information may specifically include the perception result of the road surface by the perception system and the driving state information including the current vehicle speed and the current acceleration. Then, the HCU can identify the current road condition where the vehicle is located by analyzing the perception result and the driving state information.

[0094] It should be noted that the preset road condition represents the road condition where the vehicle needs to be in the four-wheel drive mode, such as desert road conditions, muddy road conditions, and snowy road conditions, etc. Since in the power split mode, the driving mode of the vehicle is the four-wheel drive mode, therefore, compared with the series mode, the power split mode can better adapt to the preset road conditions; the power threshold represents the charging balance point of the power battery. For example, it can be set to 20%. That is, when the current SOC of the power battery is less than 20%, it means that the power battery has a charging requirement.

[0095] In this embodiment, by analyzing the operating conditions information, the vehicle can be automatically controlled to switch from the direct drive mode to the power split mode, effectively meeting the driving needs of the driver under the preset road conditions while meeting the charging requirements of the power battery, thereby realizing the intelligent switching of the vehicle mode.

[0096] S202: When it is determined that the vehicle meets the mode switching condition, keep the clutch 102 in the closed state, and adjust the torques of the engine 101 and the first motor 103 so that the first synchronizer 105 meets the gear shifting condition;

[0097] In this embodiment, after the HCU determines that the vehicle meets the mode switching condition for switching from the direct drive mode to the power split mode, it will send a clutch state holding request to the transmission controller, so that the transmission controller responds to the clutch state holding request and keeps the clutch 102 in the closed state; at the same time, it sends an engine torque adjustment request to the engine controller, so that the engine controller responds to the engine torque adjustment request and adjusts the torque of the engine 101; at the same time, it also sends a motor torque adjustment request to the motor controller, so that the motor controller responds to the motor torque adjustment request and adjusts the torque of the first motor 103.

[0098] It should be noted that when the vehicle switches from the direct drive mode to the power split mode, the first synchronizer 105 needs to shift from the engaged gear to the power split gear. If the torque applied to the first synchronizer 105 is too large when the first synchronizer 105 shifts gears, it may cause the first synchronizer 105 to fail to shift gears smoothly or be damaged during gear shifting.

[0099] In this embodiment, in order to avoid the first synchronizer 105 from failing to shift gears smoothly, the torques of the engine 101 and the first motor 103 will be adjusted so that the torque jointly acting on the first synchronizer 105 by the engine 101 and the first motor 103 through the power split mechanism 104 is a smaller value, preferably zero. In this way, the torque at the first synchronizer 105 can be reduced to the torque required for gear shifting without opening the clutch 102, so that the first synchronizer 105 can meet the gear shifting condition.

[0100] S203: When the first synchronizer 105 meets the gear shifting condition, control the first synchronizer 105 to switch from the engaged gear to the power split gear, so that the vehicle switches from the direct drive mode to the power split mode.

[0101] In this embodiment, after the HCU detects that the first synchronizer 105 meets the gear shifting condition, it will send a gear shifting request indicating that the target gear is the power split gear to the transmission controller, so that the transmission controller responds to the gear shifting request and controls the first synchronizer 105 to switch from the engaged gear to the power split gear.

[0102] In this embodiment, by adjusting the torques of the engine 101 and the first motor 103, the first synchronizer 105 can perform a gear shifting operation when the gear shifting condition is met, thereby effectively ensuring the shifting safety of the first synchronizer 105.

[0103] In this embodiment, after the HCU determines that the first synchronizer 105 has been switched to the power split gear, it will set the current driving mode of the vehicle from the direct drive mode to the power split mode, and then control the torques output by the engine 101, the first motor 103 and the second motor according to the torque distribution strategy in the power split mode.

[0104] Specifically, the torque distribution strategy includes a front axle torque distribution strategy and a rear axle torque output strategy. Among them, the HCU is used to execute the front axle torque distribution strategy, control the engine 101 to output a first torque with a positive value, and control the first motor 103 to output a second torque with a negative value to charge the power battery while driving the front axle of the vehicle; at the same time, the HCU is also used to execute the rear axle torque output strategy, control the second motor to output a third torque with a positive value to drive the rear axle of the vehicle.

[0105] It should be noted that the absolute value of the second torque. In this way, the first torque transmitted from the engine 101 to the power split mechanism 104 can be divided by the power split mechanism 104 into a generator sub-torque and a driving sub-torque. Among them, the generator sub-torque is equal to the absolute value of the second torque, and is used to be transmitted to the first motor 103 through the power split mechanism 104 to drive the first motor 103 to generate electricity, and the generated electric energy is provided to charge the power battery; the driving sub-torque is the difference between the first torque and the absolute value of the second torque, and is used to be transmitted to the transmission input shaft 107 through the power split mechanism 104, and then the transmission input shaft 107 is sequentially transmitted to the front axle of the vehicle through the second synchronizer 106, the transmission output shaft 108 and the front axle differential 109 to drive the vehicle to travel.

[0106] A vehicle mode switching method provided by an embodiment of the present application adjusts the torques of the engine 101 and the first motor 103, so that during the vehicle mode switching process, the gear shifting operation of the first synchronizer 105 can be smoothly completed without opening or closing the clutch 102. In this way, the vehicle can switch from the direct drive mode to the power split mode more quickly and smoothly, effectively shortening the mode switching duration while enabling the engine 101 to quickly output torque, thereby improving the power response performance of the vehicle during the mode switching process.

[0107] In a feasible embodiment, the step of adjusting the torques of the engine 101 and the first motor 103 in S202 may specifically include the following sub-steps:

[0108] S202-1: When the current motor torque of the first motor 103 is negative torque, keep the current motor torque unchanged, and based on the current motor torque, adjust the torque of the engine 101.

[0109] It should be noted that in the direct drive mode, the first motor 103 may have the following two working states: the power generation state and the driving state.

[0110] In the power generation state, the current motor torque of the first motor 103 is negative torque. At this time, the first motor 103 is usually used to adjust the operating point of the engine 101 so that the engine 101 can operate in the best economic range.

[0111] In the driving state, the current motor torque of the first motor 103 is positive torque. At this time, the driver has a large power demand, and the engine 101 and the first motor 103 are required to jointly drive the vehicle.

[0112] In this embodiment, for the two possible working states of the first motor 103, corresponding torque adjustment strategies will be matched.

[0113] Specifically, when the HCU determines that the vehicle meets the mode switching condition, if it detects that the current motor torque of the first motor 103 is negative torque, it will keep the current motor torque unchanged, that is, maintain the first motor 103 to charge the power battery, and based on the current motor torque, adjust the torque of the engine 101.

[0114] In this embodiment, considering that when the clutch 102 is closed, the torques of the engine 101 and the first motor 103 can be applied to the power split mechanism 104 at the same time. Therefore, by adjusting the current engine torque of the engine 101, the torque applied by the engine 101 to the power split mechanism 104 can be used to offset the negative torque applied by the first motor 103 to the power split mechanism 104, and then the torque acting on the first synchronizer 105 by the power split mechanism 104 can be adjusted. In this way, without opening the clutch 102 and maintaining the power generation of the first motor 103, the torque at the first synchronizer 105 can be balanced to the torque required for gear disengagement, so that the first synchronizer 105 meets the gear shifting condition.

[0115] S202-2: When the current motor torque of the first motor 103 is positive torque, control the current engine torque of the engine 101 and the current motor torque of the first motor 103 to follow the preset target torque.

[0116] In this embodiment, when the HCU determines that the vehicle meets the mode switching conditions, if it detects that the current motor torque of the first motor 103 is positive torque, since the engine 101 cannot cancel the torque of the first motor 103 at this time, therefore, the HCU will adjust the torques of the engine 101 and the first motor 103 simultaneously according to the target torque, so as to reduce the torque jointly applied by the engine 101 and the first motor 103 at the first synchronizer 105 to the torque required for gear disengagement, so that the first synchronizer 105 meets the gear shifting conditions.

[0117] In this embodiment, for the case where the current motor torque of the first motor 103 is positive torque, by simultaneously controlling the engine 101 and the first motor 103 to reduce to the target torque, the shifting safety of the first synchronizer 105 can be effectively ensured. For the case where the current motor torque of the first motor 103 is negative torque, by keeping the first motor 103 in the power generation state, on the one hand, the charging requirement of the power battery can be continuously met, and on the other hand, the shifting operation of the first synchronizer 105 can be realized only by adjusting the torque of the engine 101, thereby further improving the shifting speed on the premise of ensuring shifting safety.

[0118] In a feasible embodiment, continue to refer to Figure 1 , the power split mechanism 104 may specifically include a ring gear 1041, a sun gear 1042, a plurality of planet gears 1043 meshing between the ring gear 1041 and the sun gear 1042, and a planet carrier 1044 rotatably connected to the plurality of planet gears 1043; the planet carrier 1044 is connected to the engine 101 as the first input end of the power split mechanism 104, the sun gear 1042 is connected to the first motor 103 as the second input end of the power split mechanism 104, the ring gear 1041 is connected to the transmission input shaft 107 as the output end of the power split mechanism 104, and the first synchronizer 105 is arranged between the planet carrier 1044 and the ring gear 1041.

[0119] It should be noted that in the power split mode, the first synchronizer 105 is in the power split gear. At this time, the planet carrier 1044 and the ring gear 1041 are in a disconnected state. The driving force output by the engine 101 will be transmitted to the planet carrier 1044 through the clutch 102, and the planet carrier 1044 will transmit a part of the driving force to the first motor 103 through the plurality of planet gears 1043 and the sun gear 1042 in sequence to drive the first motor 103 to charge the power battery; at the same time, the planet carrier 1044 will transmit another part of the driving force to the vehicle front axle through the plurality of planet gears 1043, the ring gear 1041, the transmission input shaft 107, the second synchronizer 106, the transmission output shaft 108 and the front axle differential 109 in sequence to drive the vehicle to travel.

[0120] In the direct drive mode, the first synchronizer 105 is in the engaged gear. At this time, the planet carrier 1044 and the ring gear 1041 are in the locked state. The driving force output by the engine 101 will be transmitted to the transmission input shaft 107 through the planet carrier 1044, the first synchronizer 105, and the ring gear 1041 in sequence. The driving force output by the first motor 103 will be transmitted to the transmission input shaft 107 through the sun gear 1042, multiple planet gears 1043, and the ring gear 1041. That is, the engine 101 and the first motor 103 transmit the driving force to the transmission input shaft 107 together through two different power paths, and then the transmission input shaft 107 transmits this part of the driving force to the vehicle front axle through the second synchronizer 106, the transmission output shaft 108, and the front axle differential 109 in sequence to drive the vehicle to travel.

[0121] Based on the above structure, the step of adjusting the torque of the engine 101 based on the current motor torque in S202-1 may specifically include the following sub-steps:

[0122] S202-1-1: When the current gear of the first synchronizer 105 is the engaged gear, determine that the transmission ratio between the sun gear 1042 and the planet carrier 1044 is the first transmission ratio.

[0123] It should be noted that since the first synchronizer 105 has different transmission ratios between the planet carrier 1044 and the ring gear 1041 in different gears, and the sun gear 1042 has the same speed as the first motor 103, and the planet carrier 1044 has the same speed as the engine 101, therefore, based on the current gear of the first synchronizer 105, the transmission ratio between the first motor 103 and the engine 101 can be determined.

[0124] In this embodiment, since the current gear of the first synchronizer 105 is the engaged gear before shifting, the HCU will determine that the transmission ratio between the sun gear 1042 and the planet carrier 1044 is the first transmission ratio.

[0125] S202-1-2: Based on the current motor torque of the first motor 103 and the first transmission ratio, determine the target engine torque of the engine 101.

[0126] In this embodiment, since the speed and torque are in an inverse proportional relationship, the HCU will keep the current motor torque of the first motor 103 unchanged, and based on the first transmission ratio and the current motor torque of the first motor 103, the target engine torque of the engine 101 can be calculated inversely.

[0127] S202-1-3: Based on the preset torque adjustment gradient, control the current engine torque of the engine 101 to gradually decrease to the target engine torque.

[0128] In this embodiment, after determining the target engine torque, the HCU will activate the torque control mode of the engine controller so that the engine controller adjusts the current engine torque of the engine 101 to the target engine torque.

[0129] In a specific implementation, the current engine torque of the engine 101 can be controlled to follow the target engine torque according to a preset torque adjustment gradient. The torque adjustment gradient represents the change in torque per unit time. For example, it can be set to 200 N·m / s.

[0130] In this embodiment, by adjusting the torque of the engine 101 according to the torque adjustment gradient, it is possible to prevent the torque of the engine 101 from changing too much and affecting the driving smoothness of the vehicle.

[0131] In a feasible embodiment, the step of controlling the current engine torque of the engine 101 and the current motor torque of the first motor 103 to follow a preset target torque in S202-2 may specifically include the following sub-steps:

[0132] S202-2-1: Based on a preset torque adjustment gradient, control the current engine torque of the engine 101 and the current motor torque of the first motor 103 to gradually decrease to the target torque.

[0133] It should be noted that the target torque represents the torque at which the first synchronizer 105 can shift from the engaged gear to the power split gear. Specifically, this target torque can be set according to actual shifting requirements. For example, to maximize the service life of the first synchronizer 105, this target torque can be set to zero; or to maximize the shifting speed, this target torque can be set to the maximum torque that can achieve gear disengagement; or this target torque can be set to a torque between zero and the maximum torque, thereby to a certain extent ensuring the service life of the first synchronizer 105 while increasing the shifting speed.

[0134] In this embodiment, after determining the target torque, the HCU will activate the torque control mode of the motor controller so that the motor controller adjusts the current motor torque of the first motor 103 to the target torque; at the same time, the HCU will also activate the torque control mode of the engine controller so that the engine controller adjusts the current engine torque of the engine 101 to the target torque.

[0135] In a specific implementation, the current engine torque of the engine 101 and the current motor torque of the first motor 103 can gradually reach the target torque according to a preset torque adjustment gradient.

[0136] In this embodiment, by adjusting the torques of the engine 101 and the first motor 103 according to the torque adjustment gradient, it is possible to avoid drastic torque changes that may affect the driving smoothness of the vehicle.

[0137] In a feasible embodiment, after the step of adjusting the torque of the engine 101 based on the current motor torque, the vehicle mode switching method may further include the following steps:

[0138] S301: When the first torque difference between the current engine torque and the target engine torque of the engine 101 is less than the first torque threshold, trigger the timing for a first duration during which the first torque difference is less than the first torque threshold.

[0139] It should be noted that when the current motor torque of the first motor 103 is a negative torque, that is, when the first motor 103 is in the power generation state, only the torque of the engine 101 needs to be adjusted.

[0140] In this embodiment, during the process of the HCU adjusting the torque of the engine 101, the current engine torque real-time feedback by the engine controller will be obtained. Then, when it is detected that the first torque difference between the current engine torque and the target engine torque is less than the first torque threshold, the first timer will accumulate and time for the first duration. Then, based on the first duration, it is determined whether the engine 101 is stably operating at the target engine torque. Among them, the first torque threshold can be set to 5 N·m; the first duration represents the duration during which the engine 101 continuously and stably operates near the target engine torque.

[0141] S302: When the first duration is greater than the first duration threshold, determine that the first synchronizer 105 meets the gear shifting condition.

[0142] In this embodiment, if the HCU detects that the first duration is greater than the first duration threshold, it is considered that the engine 101 is stably operating near the target engine torque, and the torque fluctuation range of the engine 101 is small. Then, it is determined that the first synchronizer 105 meets the gear shifting condition.

[0143] In this embodiment, by monitoring the first duration, it is possible to effectively avoid controlling the first synchronizer 105 to perform a gear disengaging operation when the engine 101 has abnormal torque fluctuations, thereby ensuring that the first synchronizer 105 can shift gears smoothly.

[0144] In a feasible embodiment, after the step of controlling the current engine torque of the engine 101 and the current motor torque of the first motor 103 to follow a preset target torque, the vehicle mode switching method may further include the following steps:

[0145] S401: When the second torque difference between the current engine torque and the target torque of the engine 101 is less than the second torque threshold, trigger the timing for the second duration during which the second torque difference is less than the second torque threshold.

[0146] It should be noted that when the current motor torque of the first motor 103 is a positive torque, that is, when the first motor 103 is in the driving state, it is necessary to simultaneously control the engine 101 and the first motor 103 to decrease to the target torque.

[0147] In this embodiment, during the process of the HCU adjusting the torque of the engine 101, it will obtain the current engine torque real-time feedback by the engine controller. Then, when it detects that the second torque difference between the current engine torque and the target torque is less than the second torque threshold, it triggers the cumulative timing for the second duration through the second timer. Then, based on the second duration, it determines whether the engine 101 is stably operating near the target torque.

[0148] S402: When the third torque difference between the current motor torque and the target torque of the first motor 103 is less than the third torque threshold, trigger the timing for the third duration during which the third torque difference is less than the third torque threshold.

[0149] In this embodiment, during the process of the HCU adjusting the torque of the first motor 103, it will also obtain the current motor torque of the first motor 103 real-time feedback by the motor controller. Then, when it detects that the third torque difference between the current motor torque and the target torque is less than the third torque threshold, it triggers the cumulative timing for the third duration through the third timer. Then, based on the third duration, it determines whether the first motor 103 is stably operating near the target torque.

[0150] S403: When the second duration is greater than the second duration threshold and the third duration is greater than the third duration threshold, determine that the first synchronizer 105 meets the gear shifting condition.

[0151] In this embodiment, if the HCU detects that both the second duration and the third duration are greater than their respective duration thresholds, it considers that both the engine 101 and the first motor 103 are stably operating near the target torque, and then determines that the first synchronizer 105 has met the gear shifting condition.

[0152] In this embodiment, by monitoring the second duration and the third duration, it can effectively avoid controlling the first synchronizer 105 to perform gear disengaging operation in the case of abnormal torque fluctuations of the engine 101 or the first motor 103, and then ensure that the first synchronizer 105 can shift gears smoothly.

[0153] In a feasible implementation, the vehicle further includes a second motor, and the vehicle mode switching method may further include the following steps:

[0154] S501: Determine the compensation torque of the second motor based on the current engine torque and the current motor torque.

[0155] In this implementation, considering that whether the first motor 103 is in the driving state or the power generation state, during the process of torque adjustment of the engine 101 and the first motor 103, the front axle torque will continuously decrease. To ensure the power demand of the whole vehicle during the mode switching process, torque compensation will be performed by the second motor.

[0156] In a specific implementation, the sum of the current engine torque and the current motor torque can be determined as the compensation torque of the second motor. It should be noted that the current engine torque represents the engine torque before torque adjustment of the engine 101 and the first motor 103; the current motor torque represents the motor torque before torque adjustment of the engine 101 and the first motor 103.

[0157] In an example, when the HCU determines that the vehicle meets the mode switching condition, if it detects that the current engine torque is 800 N·m and the current motor torque is -300 N·m, the compensation torque of the second motor is 500 N·m.

[0158] In another example, when the HCU determines that the vehicle meets the mode switching condition, if it detects that the current engine torque is 400 N·m and the current motor torque is 200 N·m, the compensation torque of the second motor is 600 N·m.

[0159] S502: Determine the target driving torque of the second motor based on the compensation torque and the current driving torque of the second motor.

[0160] In this implementation, the HCU will further superimpose the compensation torque on the current driving torque of the second motor to obtain the target driving torque of the second motor. Then, the second motor can supplement the reduced torque of the vehicle front axle at the vehicle rear axle.

[0161] S503: During the process of torque adjustment of the engine 101 and the first motor 103, control the second motor to gradually increase from the current driving torque to the target driving torque based on a preset torque adjustment gradient.

[0162] In this implementation, during the process of torque adjustment of the engine 101 and the first motor 103 according to the torque adjustment gradient, the HCU will also synchronously control the second motor to perform torque compensation according to the same torque adjustment gradient.

[0163] In one example, the torque adjustment gradient is set to 200 N·m / s. When the HCU determines that the vehicle meets the mode switching condition, if it detects that the engine 101 outputs 800 N·m, the first motor 103 outputs -300 N·m, and the second motor outputs 400 N·m, the HCU will keep the output of the first motor 103 at -300 N·m unchanged, and control the engine 101 to gradually decrease from 800 N·m to 300 N·m according to the torque adjustment gradient of 200 N·m / s; at the same time, the compensation torque of the second motor is calculated to be 500 N·m, and the target driving torque is 900 N·m. Furthermore, the second motor is synchronously controlled to gradually increase from 400 N·m to 900 N·m according to the torque adjustment gradient of 200 N·m / s.

[0164] In another example, the torque adjustment gradient is set to 200 N·m / s, and the target torque is set to 0 N·m. If the HCU detects that the engine 101 outputs 400 N·m, the first motor 103 outputs 200 N·m, and the second motor outputs 400 N·m, and then after detecting that the vehicle meets the mode switching request, the HCU will control the engine 101 to gradually decrease from 800 N·m to 0 N·m according to the torque adjustment gradient of 200 N·m / s, and control the first motor 103 to gradually increase from -300 N·m to 0 N·m; at the same time, the compensation torque of the second motor is calculated to be 600 N·m, and the target driving torque is 1000 N·m. Furthermore, the second motor is synchronously controlled to gradually increase from 400 N·m to 1000 N·m according to the torque adjustment gradient of 200 N·m / s.

[0165] In this embodiment, torque compensation is performed by the second motor, so that during the mode switching process, regardless of whether the first motor 103 is in the power generation state or the driving state, the vehicle power performance can be kept consistent, thereby effectively meeting the driver's power demand during the mode switching process, and at the same time avoiding phenomena such as unexpected deceleration or jerks of the vehicle.

[0166] Second, based on the same inventive concept, referring to Figure 3 , the embodiment of the present application provides a vehicle mode switching device 300. The vehicle includes an engine 101, a clutch 102, a first motor 103 and a gearbox; the gearbox includes a power split mechanism 104, a first synchronizer 105 and a gearbox input shaft 107. The engine 101 is connected to the first input end of the power split mechanism 104 through the clutch 102, the first motor 103 is connected to the second input end of the power split mechanism 104, the output end of the power split mechanism 104 is connected to the gearbox input shaft 107, and the first synchronizer 105 is arranged between the first input end and the output end; the vehicle mode switching device 300 includes:

[0167] A condition determination module 301, configured to determine whether the vehicle meets the mode switching condition for switching from the direct drive mode to the power split mode based on the operating condition information of the vehicle when the vehicle is in the direct drive mode;

[0168] A torque adjustment module 302, configured to keep the clutch 102 in a closed state and adjust the torques of the engine 101 and the first motor 103 to enable the first synchronizer 105 to meet the gear switching condition when it is determined that the vehicle meets the mode switching condition;

[0169] A gear switching module 303, configured to control the first synchronizer 105 to switch from the engaged gear to the power split gear when the first synchronizer 105 meets the gear switching condition, so that the vehicle switches from the direct drive mode to the power split mode.

[0170] In an embodiment of the present application, the operating condition information includes road condition information and the current remaining power of the power battery; the condition determination module 301 includes:

[0171] A road condition determination sub-module, configured to determine the current road condition of the vehicle based on the road condition information when the current remaining power is less than the power threshold;

[0172] A condition determination sub-module, configured to determine that the vehicle meets the mode switching condition for switching from the direct drive mode to the power split mode when the current road condition is a preset road condition.

[0173] In an embodiment of the present application, the torque adjustment module 302 includes:

[0174] A first torque adjustment sub-module, configured to keep the current motor torque unchanged and adjust the torque of the engine 101 based on the current motor torque when the current motor torque of the first motor 103 is a negative torque;

[0175] A second torque adjustment sub-module, configured to control the current engine torque of the engine 101 and the current motor torque of the first motor 103 to follow a preset target torque when the current motor torque of the first motor 103 is a positive torque.

[0176] In an embodiment of the present application, the power splitting mechanism 104 includes a ring gear 1041, a sun gear 1042, a plurality of planet gears 1043 meshing between the ring gear 1041 and the sun gear 1042, and a planet carrier 1044 rotatably connected to the plurality of planet gears 1043; the planet carrier 1044 is connected to the engine 101 as the first input end of the power splitting mechanism 104, the sun gear 1042 is connected to the first motor 103 as the second input end of the power splitting mechanism 104, the ring gear 1041 is connected to the transmission input shaft 107 as the output end of the power splitting mechanism 104, and the first synchronizer 105 is disposed between the planet carrier 1044 and the ring gear 1041; the first torque adjustment sub-module includes:

[0177] A gear ratio determination unit, configured to determine that the gear ratio between the sun gear and the planet carrier is a first gear ratio when the current gear position of the first synchronizer 105 is an engaged gear position;

[0178] An engine torque determination unit, configured to determine the target engine torque of the engine 101 based on the current motor torque of the first motor 103 and the first gear ratio;

[0179] A first torque adjustment unit, configured to control the current engine torque of the engine 101 to gradually decrease to the target engine torque based on a preset torque adjustment gradient.

[0180] In an embodiment of the present application, the second torque adjustment sub-module includes:

[0181] A second torque adjustment unit, configured to control the current engine torque of the engine 101 and the current motor torque of the first motor 103 to gradually decrease to the target torque based on a preset torque adjustment gradient.

[0182] In an embodiment of the present application, the vehicle further includes a second motor, and the vehicle mode switching device further includes:

[0183] A compensation torque determination module, configured to determine the compensation torque of the second motor based on the current engine torque and the current motor torque;

[0184] A drive torque determination module, configured to determine the target drive torque of the second motor based on the compensation torque and the current drive torque of the second motor;

[0185] A drive torque control module, configured to control the second motor to gradually increase from the current drive torque to the target drive torque based on a preset torque adjustment gradient during the process of adjusting the torques of the engine 101 and the first motor 103.

[0186] In an embodiment of the present application, the vehicle mode switching device 300 further includes:

[0187] The first timing module is configured to trigger timing for a first duration during which the first torque difference between the current engine torque and the target engine torque of the engine 101 is less than a first torque threshold when the first torque difference is less than the first torque threshold.

[0188] The first switching condition determination module is configured to determine that the first synchronizer 105 meets the gear shifting condition when the first duration is greater than a first duration threshold.

[0189] In an embodiment of the present application, the vehicle mode switching device 300 further includes:

[0190] The second timing module is configured to trigger timing for a second duration during which the second torque difference between the current engine torque and the target torque of the engine 101 is less than a second torque threshold when the second torque difference is less than the second torque threshold.

[0191] The third timing module is configured to trigger timing for a third duration during which the third torque difference between the current motor torque and the target torque of the first motor 103 is less than a third torque threshold when the third torque difference is less than the third torque threshold.

[0192] The second switching condition determination module is configured to determine that the first synchronizer 105 meets the gear shifting condition when the second duration is greater than a second duration threshold and the third duration is greater than a third duration threshold.

[0193] It should be noted that the specific implementation manner of the vehicle mode switching device 300 in the embodiments of the present application refers to the specific implementation manner of the vehicle mode switching method proposed in the first aspect of the embodiments of the present application, which will not be elaborated herein.

[0194] In a third aspect, based on the same inventive concept, referring to Figure 4 , an embodiment of the present application provides a vehicle mode switching system 400. The vehicle includes an engine 101, a clutch 102, a first motor 103, and a gearbox. The gearbox includes a power split mechanism 104, a first synchronizer 105, and a gearbox input shaft 107. The engine 101 is connected to a first input end of the power split mechanism 104 through the clutch 102. The first motor 103 is connected to a second input end of the power split mechanism 104. The output end of the power split mechanism 104 is connected to the gearbox input shaft 107. The first synchronizer 105 is disposed between the first input end and the output end. The vehicle mode switching system 400 includes a vehicle controller 401, a gearbox controller 402, a motor controller 403, and an engine controller 404.

[0195] The vehicle controller 401 is configured to, when the vehicle is in the direct drive mode, determine whether the vehicle meets the mode switching condition for switching from the direct drive mode to the power split mode based on the vehicle operating condition information, and when it is determined that the vehicle meets the mode switching condition, send a clutch state holding request to the transmission controller 402, send an engine torque adjustment request to the engine controller 404, and send a motor torque adjustment request to the motor controller 403;

[0196] The transmission controller 402 is configured to keep the clutch 102 in the closed state in response to the clutch state holding request;

[0197] The engine controller 404 is configured to adjust the torque of the engine 101 in response to the engine torque adjustment request, and the motor controller 403 is configured to adjust the torque of the first motor 103 in response to the motor torque adjustment request, so that the first synchronizer 105 meets the gear shifting condition;

[0198] The vehicle controller 401 is further configured to send a gear shifting request to the transmission controller 402 when the first synchronizer 105 meets the gear shifting condition;

[0199] The transmission controller 402 is further configured to control the first synchronizer 105 to switch from the engaged gear to the power split gear in response to the gear shifting request, so that the vehicle switches from the direct drive mode to the power split mode.

[0200] It should be noted that the specific implementation of the vehicle mode switching system 400 in the embodiments of the present application refers to the specific implementation of the vehicle mode switching method proposed in the first aspect of the present application described above, and will not be elaborated here.

[0201] Fourthly, based on the same inventive concept, referring to Figure 5 , the embodiments of the present application provide a vehicle 500, including the vehicle mode switching system 400 proposed in the third aspect of the present application.

[0202] It should be noted that the specific implementation of the vehicle 500 in the embodiments of the present application refers to the specific implementation of the vehicle mode switching system 400 proposed in the third aspect of the present application described above, and will not be elaborated here.

[0203] Those skilled in the art should understand that the embodiments of the present invention can be provided as a method, an apparatus, or a computer program product. Therefore, the embodiments of the present invention can take the form of an all-hardware embodiment, an all-software embodiment, or an embodiment combining software and hardware aspects. Moreover, the embodiments of the present invention can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0204] Embodiments of the present invention are described with reference to the flowcharts and / or block diagrams of methods, terminal devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, and the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing terminal devices to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing terminal devices generate means for implementing the functions specified in one process Figure 1 one process or multiple processes and / or blocks Figure 1 or multiple blocks.

[0205] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing terminal device to work in a specific manner, so that the instructions stored in the computer-readable memory generate a manufactured article including instruction means, and the instruction means implement the functions specified in one process Figure 1 one process or multiple processes and / or blocks Figure 1 or multiple blocks.

[0206] These computer program instructions can also be loaded onto a computer or other programmable data processing terminal device, so that a series of operation steps are executed on the computer or other programmable terminal device to generate a computer-implemented process, and thus the instructions executed on the computer or other programmable terminal device provide steps for implementing the functions specified in one process Figure 1 one process or multiple processes and / or blocks Figure 1 or multiple blocks.

[0207] Although the preferred embodiments of the embodiments of the present invention have been described, those skilled in the art can make additional changes and modifications to these embodiments once they know the basic creative concepts. Therefore, the appended claims are intended to be construed as including the preferred embodiments and all changes and modifications falling within the scope of the embodiments of the present invention.

[0208] Finally, it should also be noted that in this text, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or terminal device comprising a series of elements not only includes those elements, but also includes other elements not expressly listed, or also includes elements inherent in such process, method, article or terminal device. Without further limitation, an element defined by the statement "comprising an..." does not exclude the presence of additional identical elements in the process, method, article or terminal device comprising the element.

[0209] The above has introduced in detail a vehicle mode switching method, system and vehicle provided by the present invention. Specific examples are used in this text to elaborate on the principle and implementation manner of the present invention. The description of the above embodiments is only used to help understand the method and its core idea of the present invention; at the same time, for those of ordinary skill in the art, according to the idea of the present invention, there will be changes in the specific implementation manner and application scope. In summary, the content of this specification should not be construed as a limitation to the present invention.

Claims

1. A vehicle mode switching method, characterized in that, The vehicle includes an engine, a clutch, a first motor, and a transmission; the transmission includes a power split mechanism, a first synchronizer, and a transmission input shaft. The engine is connected to a first input end of the power split mechanism through the clutch, the first motor is connected to a second input end of the power split mechanism, an output end of the power split mechanism is connected to the transmission input shaft, and the first synchronizer is arranged between the first input end and the output end; the method includes: When the vehicle is in the direct drive mode, based on the operating condition information of the vehicle, determine whether the vehicle meets the mode switching condition for switching from the direct drive mode to the power split mode; When it is determined that the vehicle meets the mode switching condition, keep the clutch in a closed state, and perform torque adjustment on the engine and the first motor so that the first synchronizer meets the gear shifting condition; When the first synchronizer meets the gear shifting condition, control the first synchronizer to switch from the engaged gear to the power split gear so that the vehicle switches from the direct drive mode to the power split mode.

2. The vehicle mode switching method according to claim 1, wherein The operating condition information includes road condition information and the current remaining power of the power battery; The step of determining whether the vehicle meets the mode switching condition for switching from the direct drive mode to the power split mode based on the operating condition information of the vehicle includes: When the current remaining power is less than the power threshold, based on the road condition information, determine the current road condition where the vehicle is located; When the current road condition is a preset road condition, determine that the vehicle meets the mode switching condition for switching from the direct drive mode to the power split mode.

3. The vehicle mode switching method according to claim 1, wherein The step of performing torque adjustment on the engine and the first motor includes: When the current motor torque of the first motor is a negative torque, keep the current motor torque unchanged, and perform torque adjustment on the engine based on the current motor torque; When the current motor torque of the first motor is a positive torque, control the current engine torque of the engine and the current motor torque of the first motor to follow a preset target torque.

4. The vehicle mode switching method according to claim 3, wherein The power split mechanism includes a ring gear, a sun gear, a plurality of planet gears meshing between the ring gear and the sun gear, and a planet carrier rotatably connected to the plurality of planet gears; the planet carrier is connected to the engine as the first input end, the sun gear is connected to the first motor as the second input end, the ring gear is connected to the transmission input shaft as the output end, and the first synchronizer is arranged between the planet carrier and the ring gear; The step of performing torque adjustment on the engine based on the current motor torque includes: When the current gear position of the first synchronizer is the engaged gear, determine that the transmission ratio between the sun gear and the planet carrier is a first transmission ratio; Based on the current motor torque of the first motor and the first transmission ratio, determine the target engine torque of the engine; Based on a preset torque adjustment gradient, control the current engine torque of the engine to gradually decrease to the target engine torque.

5. The vehicle mode switching method according to claim 3, wherein Steps of controlling the current engine torque of the engine and the current motor torque of the first motor to follow a preset target torque include: Based on a preset torque adjustment gradient, controlling the current engine torque of the engine and the current motor torque of the first motor to gradually decrease to the target torque.

6. The vehicle mode switching method according to claim 4, wherein, After the step of adjusting the torque of the engine based on the current motor torque, the method further includes: When a first torque difference between the current engine torque of the engine and the target engine torque is less than a first torque threshold, triggering a timing for a first duration during which the first torque difference is less than the first torque threshold; When the first duration is greater than a first duration threshold, determining that the first synchronizer meets the gear shifting condition.

7. The vehicle mode switching method according to claim 3, wherein After the steps of controlling the current engine torque of the engine and the current motor torque of the first motor to follow a preset target torque, the method further includes: When a second torque difference between the current engine torque of the engine and the target torque is less than a second torque threshold, triggering a timing for a second duration during which the second torque difference is less than the second torque threshold; When a third torque difference between the current motor torque of the first motor and the target torque is less than a third torque threshold, triggering a timing for a third duration during which the third torque difference is less than the third torque threshold; When the second duration is greater than a second duration threshold and the third duration is greater than a third duration threshold, determining that the first synchronizer meets the gear shifting condition.

8. The vehicle mode switching method according to claim 3, wherein The vehicle further includes a second motor, and the method further includes: Based on the current engine torque and the current motor torque, determining a compensation torque for the second motor; Based on the compensation torque and the current driving torque of the second motor, determining a target driving torque for the second motor; During the process of adjusting the torque of the engine and the first motor, based on a preset torque adjustment gradient, controlling the second motor to gradually increase from the current driving torque to the target driving torque.

9. A vehicle mode switching system, characterized in that, The vehicle includes an engine, a clutch, a first motor, and a gearbox; the gearbox includes a power splitting mechanism, a first synchronizer, and a gearbox input shaft. The engine is connected to a first input end of the power splitting mechanism through the clutch, the first motor is connected to a second input end of the power splitting mechanism, an output end of the power splitting mechanism is connected to the gearbox input shaft, and the first synchronizer is arranged between the first input end and the output end; the system includes a vehicle controller, a gearbox controller, a motor controller, and an engine controller; wherein, The vehicle controller is configured to, when the vehicle is in the direct drive mode, determine whether the vehicle meets the mode switching condition for switching from the direct drive mode to the power split mode based on the vehicle operating condition information, and when it is determined that the vehicle meets the mode switching condition, send a clutch state holding request to the transmission controller, send an engine torque adjustment request to the engine controller, and send a motor torque adjustment request to the motor controller; The transmission controller is configured to keep the clutch in a closed state in response to the clutch state holding request; The engine controller is configured to adjust the torque of the engine in response to the engine torque adjustment request, and the motor controller is configured to adjust the torque of the first motor in response to the motor torque adjustment request so that the first synchronizer meets the gear shifting condition; The vehicle controller is further configured to send a gear shifting request to the transmission controller when the first synchronizer meets the gear shifting condition; The transmission controller is further configured to control the first synchronizer to switch from the engaged gear to the power split gear in response to the gear shifting request, so that the vehicle switches from the direct drive mode to the power split mode.

10. A vehicle, characterized in that, Comprising the vehicle mode switching system according to claim 9.

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