A vehicle mode switching method, system, and vehicle

Abstract

This application provides a vehicle mode switching method, system, and vehicle, belonging to the field of vehicle technology. The embodiments of this application, when the vehicle meets the mode switching conditions from power split mode to pure electric four-wheel drive mode, adjust the torque of the engine and the first motor to quickly disengage the clutch and control the engine to stop. Then, by adjusting the speed of the first motor while the clutch is open, the rapid closing of the first synchronizer can be achieved while ensuring shifting safety. This effectively improves the mode switching speed while ensuring smooth switching and enhancing the user's driving experience.

Description

Technical Field

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

[0002] To adapt to different road conditions and driving needs, some hybrid vehicles are equipped with multiple driving modes, including a pure electric four-wheel drive mode and a power split mode. During vehicle operation, the driving modes will switch between each other under certain conditions.

[0003] Currently, when a vehicle needs to switch from power split mode to pure electric four-wheel drive mode, multiple components in the front axle, such as the engine, clutch, front axle motor, and front axle gearbox, need to be controlled to achieve the mode switch. How to control these multiple components in an orderly manner, while ensuring a smooth switch and improving the mode switch speed, is an urgent problem to be solved. Summary of the Invention

[0004] This application provides a vehicle mode switching method, system, and vehicle to solve the problem that current hybrid vehicles have difficulty in achieving rapid and stable switching from power split mode to pure electric four-wheel drive mode.

[0005] To solve the above problems, this application adopts the following technical solution:

[0006] In a first aspect, embodiments of this application provide a vehicle mode switching method, wherein 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 via the clutch, the first motor is connected to a second input end of the power splitting mechanism, the output end of the power splitting 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 meets the mode switching conditions for switching from power split mode to pure electric four-wheel drive mode, the torque of the engine and the first motor is adjusted so that the clutch meets the opening conditions.

[0008] When the clutch meets the opening condition, control the clutch to switch from the closed state to the open state, and control the engine to stop;

[0009] When the clutch is in the open state, the speed of the first motor is adjusted so that the first synchronizer meets the gear switching conditions;

[0010] When the first synchronizer meets the gear switching conditions, the first synchronizer is controlled to switch from the power split gear to the engagement gear, so that the vehicle switches from the power split mode to the pure electric four-wheel drive mode.

[0011] In one embodiment of this application, the method further includes:

[0012] In response to a user-triggered mode switching command, or when the current remaining charge of the high-voltage battery is greater than a charge threshold, the vehicle is determined to meet the mode switching conditions for switching from power split mode to pure electric four-wheel drive mode.

[0013] In one embodiment of this application, torque adjustment of the engine and the first motor includes:

[0014] Based on the preset target torque, the current motor torque of the first motor is adjusted, and based on the current motor torque, the target engine torque of the engine is determined.

[0015] Based on the target engine torque, the current engine torque of the engine is adjusted.

[0016] In one embodiment of this application, the vehicle further includes a second motor, and the method further includes:

[0017] During the torque adjustment of the engine and the first motor, the compensation torque of the second motor is determined;

[0018] Based on the compensation torque, torque compensation is performed on the current driving torque of the second motor.

[0019] In one embodiment of this application, the power splitting 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 serves as the first input end and is connected to the engine, the sun gear serves as the second input end and is connected to the first motor, the ring gear serves as the output end and is connected to the input shaft of the gearbox, and the first synchronizer is disposed between the planet carrier and the ring gear;

[0020] Based on the current motor torque, the target engine torque of the engine is determined, including:

[0021] When the current gear of the first synchronizer is the power shunt gear, the gear ratio between the planet carrier and the sun gear is determined to be the first gear ratio.

[0022] Based on the current motor torque and the first gear ratio, the target engine torque of the engine is determined.

[0023] In one embodiment of this application, the method further includes:

[0024] When the current motor torque is less than a first torque threshold and the current engine torque is less than a second torque threshold, a timer is triggered to determine the duration of the state.

[0025] If the duration of the state is greater than a duration threshold, it is determined that the clutch meets the opening condition.

[0026] In one embodiment of this application, the gearbox further includes a second synchronizer and a gearbox output shaft, wherein the second synchronizer is disposed between the gearbox input shaft and the gearbox output shaft;

[0027] Adjusting the speed of the first motor includes:

[0028] Based on the current gear position of the first synchronizer and the second synchronizer, determine the second gear ratio between the first motor and the target wheel;

[0029] Based on the current wheel speed of the target wheel and the second gear ratio, the target motor speed of the first motor is determined;

[0030] Control the current motor speed of the first motor to follow the target motor speed.

[0031] In one embodiment of this application, when the first synchronizer meets the gear switching condition, controlling the first synchronizer to switch from the power shunt gear to the engagement gear includes:

[0032] When the first synchronizer meets the gear switching conditions, the first motor is controlled to follow the preset gear shifting auxiliary torque to assist the first synchronizer in switching from the power shunt gear to the engagement gear.

[0033] Secondly, based on the same inventive concept, this application provides a vehicle mode switching device, wherein 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 via the clutch; the first motor is connected to a second input end of the power splitting mechanism; the output end of the power splitting mechanism is connected to the transmission input shaft; and the first synchronizer is disposed between the first input end and the output end; the device includes:

[0034] The torque adjustment module is used to adjust the torque of the engine and the first motor when the vehicle meets the mode switching conditions from power split mode to pure electric four-wheel drive mode, so that the clutch meets the opening conditions.

[0035] The clutch control module is used to control the clutch to switch from a closed state to an open state and to control the engine to stop when the clutch meets the opening conditions.

[0036] The speed adjustment module is used to adjust the speed of the first motor when the clutch is in the open state, so that the first synchronizer meets the gear switching conditions.

[0037] The gear shifting module is used to control the first synchronizer to switch from the power split gear to the engagement gear when the first synchronizer meets the gear shifting conditions, so that the vehicle switches from the power split mode to the pure electric four-wheel drive mode.

[0038] In one embodiment of this application, the vehicle mode switching device further includes:

[0039] The switching condition determination module is used to determine, in response to a user-triggered mode switching command, or when the current remaining charge of the high-voltage battery is greater than a charge threshold, that the vehicle meets the mode switching conditions for switching from power split mode to pure electric four-wheel drive mode.

[0040] In one embodiment of this application, the torque adjustment module includes:

[0041] The motor torque adjustment submodule is used to adjust the current motor torque of the first motor based on a preset target torque, and to determine the target engine torque of the engine based on the current motor torque.

[0042] An engine torque adjustment submodule is used to adjust the current engine torque of the engine based on the target engine torque.

[0043] In one embodiment of this application, the vehicle further includes a second motor, and the vehicle mode switching device further includes:

[0044] A torque determination module is used to determine the compensation torque of the second motor during the torque adjustment process of the engine and the first motor.

[0045] A torque compensation module is used to compensate the current drive torque of the second motor based on the compensation torque.

[0046] In one embodiment of this application, the power splitting 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 serves as the first input end and is connected to the engine, the sun gear serves as the second input end and is connected to the first motor, the ring gear serves as the output end and is connected to the input shaft of the gearbox, and the first synchronizer is disposed between the planet carrier and the ring gear;

[0047] The motor torque adjustment submodule includes:

[0048] The gear ratio determination unit is used to determine the gear ratio between the planet carrier and the sun gear as the first gear ratio when the current gear of the first synchronizer is the power shunt gear;

[0049] An engine torque determination unit is used to determine the target engine torque of the engine based on the current motor torque and the first gear ratio.

[0050] In one embodiment of this application, the vehicle mode switching device further includes:

[0051] The timing module is used to trigger a timer for the duration of the state when the current motor torque is less than a first torque threshold and the current engine torque is less than a second torque threshold.

[0052] The opening condition determination module is used to determine that the clutch meets the opening condition when the duration of the state is greater than a duration threshold.

[0053] In one embodiment of this application, the gearbox further includes a second synchronizer and a gearbox output shaft, the second synchronizer being disposed between the gearbox input shaft and the gearbox output shaft; the speed regulation module includes:

[0054] The gear ratio determination submodule is used to determine the second gear ratio between the first motor and the target wheel based on the current gear position of the first synchronizer and the second synchronizer;

[0055] The motor speed determination submodule is used to determine the target motor speed of the first motor based on the current wheel speed of the target wheel and the second gear ratio;

[0056] The motor speed control submodule is used to control the current motor speed of the first motor to follow the target motor speed.

[0057] In one embodiment of this application, the gear shifting module includes:

[0058] An auxiliary submodule is used to control the first motor to follow a preset shifting torque when the first synchronizer meets the shifting conditions, so as to assist the first synchronizer in switching from the power shunt gear to the engagement gear.

[0059] Thirdly, based on the same inventive concept, embodiments of this application provide a vehicle mode switching system. 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 terminal of the power splitting mechanism via the clutch. The first motor is connected to a second input terminal of the power splitting mechanism. The output terminal of the power splitting mechanism is connected to the transmission input shaft. The first synchronizer is disposed between the first input terminal and the output terminal. The system includes a vehicle controller, a transmission controller, a motor controller, and an engine controller.

[0060] The vehicle controller is used to send an engine torque adjustment request to the engine controller and a motor torque adjustment request to the motor controller when the vehicle meets the mode switching conditions for switching from power split mode to pure electric four-wheel drive mode.

[0061] The engine controller is configured to adjust the engine torque in response to the engine torque adjustment request;

[0062] The motor controller is configured to adjust the torque of the first motor in response to the motor torque adjustment request;

[0063] The vehicle controller is also configured to send a clutch opening request to the transmission controller when the clutch meets the opening conditions; and to send an engine shutdown request to the engine controller when the clutch is open.

[0064] The transmission controller is configured to control the clutch to open in response to the clutch opening request;

[0065] The engine controller is also configured to control the engine to shut down in response to the engine shutdown request;

[0066] The vehicle controller is also used to send a motor speed adjustment request to the motor controller when the clutch is in the open state;

[0067] The motor controller is further configured to adjust the speed of the first motor in response to the motor speed adjustment request, so that the first synchronizer meets the gear switching conditions;

[0068] The vehicle controller is further configured to send a gear shifting request to the transmission controller when the first synchronizer meets the gear shifting conditions.

[0069] The transmission controller is also configured to, in response to the gear shift request, control the first synchronizer to switch from the power split gear to the engagement gear, so that the vehicle switches from the power split mode to the pure electric four-wheel drive mode.

[0070] Fourthly, based on the same inventive concept, embodiments of this application provide a vehicle including the vehicle mode switching system proposed in the third aspect of this application.

[0071] Compared with the prior art, this application has the following advantages:

[0072] This application provides a vehicle mode switching method. First, when the vehicle meets the mode switching conditions for switching from power-split mode to pure electric four-wheel drive mode, the torque of the engine and the first motor is adjusted to allow the clutch to open. Once the clutch is open, the clutch is controlled to switch from a closed state to an open state, and the engine is stopped. Then, with the clutch open, the speed of the first motor is adjusted to allow the first synchronizer to meet the gear shifting conditions. Finally, with the first synchronizer meeting the gear shifting conditions, the first synchronizer is controlled to switch from a power-split gear to an engaged gear, thus switching the vehicle from power-split mode to pure electric four-wheel drive mode. This application embodiment, by adjusting the torque of the engine and the first motor, can quickly open the clutch and stop the engine. Then, by adjusting the speed of the first motor while the clutch is open, it can achieve rapid closure of the first synchronizer while ensuring safe gear shifting. This effectively improves the mode switching speed while ensuring smooth switching, enhancing the user's driving experience. Attached Figure Description

[0073] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0074] Figure 1 This is a schematic diagram of the structure of a hybrid vehicle in one embodiment of this application.

[0075] Figure 2 This is a flowchart of the steps of a vehicle mode switching method in one embodiment of this application.

[0076] Figure 3This is a schematic diagram of the functional modules of a vehicle mode switching device according to an embodiment of this application.

[0077] Figure 4 This is a schematic diagram of the structure of a vehicle mode switching system according to an embodiment of this application.

[0078] Figure 5 This is a structural schematic diagram of a vehicle according to one embodiment of this application. Detailed Implementation

[0079] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0080] Reference Figure 1 The diagram shows a schematic of the structure of a hybrid vehicle according to an embodiment of this application. The hybrid vehicle has an engine 101, a clutch 102, a first motor 103 and a gearbox on the front axle. The gearbox includes a power splitting 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 splitting mechanism 104 through the clutch 102, the first motor 103 is connected to the second input end of the power splitting mechanism 104, and the output end of the power splitting mechanism 104 is connected to the gearbox input shaft 107.

[0081] The first synchronizer 105 is disposed between the first input terminal and the output terminal, and is used to connect or disconnect the first input terminal and the output terminal. Specifically, when the first synchronizer 105 is in the connected position, it connects the first input terminal and the output terminal; when the first synchronizer 105 is in the power-split position, it disconnects the first input terminal and the output terminal. 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 position, the vehicle can be in the power-split mode; when the first synchronizer 105 is in the connected position, the vehicle can be in other modes besides the power-split mode, such as pure electric four-wheel drive mode, series mode, or direct drive mode.

[0082] The second synchronizer 106 is disposed between the transmission input shaft 107 and the transmission output shaft 108, and is used to engage or disengage the transmission input shaft 107 and the transmission output shaft 108. Specifically, when the second synchronizer 106 is in gear, it engages the transmission input shaft 107 and the transmission output shaft 108; when the second synchronizer 106 is in neutral, it disengages the transmission input shaft 107 and the transmission output shaft 108.

[0083] Furthermore, the gearbox output shaft 108 is also connected to the front axle wheels via the front axle differential 109, for transmitting power to the front axle wheels via the front axle differential 109 to drive the front axle of the vehicle; the hybrid vehicle is also equipped with a second motor (not shown in the figure) on the rear axle of the vehicle, which is used to transmit power to the rear axle wheels via the rear axle differential (not shown in the figure) to drive the rear axle of the vehicle.

[0084] Hybrid vehicles employing the aforementioned architecture are equipped with a power split mechanism 104, which is connected to the engine 101, the first motor 103, and the transmission input shaft 107. This allows the vehicle to operate in multiple driving modes, including a power split mode and a pure electric four-wheel drive mode. Furthermore, by changing the gear positions of the engine 101, clutch 102, first synchronizer 105, and second synchronizer 106, switching between different driving modes can be achieved.

[0085] In power split mode, the first synchronizer 105 is in the power split gear, which is in the disengaged state to disconnect the first input and output terminals. The second synchronizer 106 is in the engaged state, the engine 101 is in the driving state, the clutch 102 is in the engaged state, the first motor 103 is in the generating 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 terminal. The power split mechanism 104 then transmits a portion of the driving force to the first motor 103 through the second input terminal to drive the first motor 103 to generate electricity (at this time, the first motor 103 outputs negative torque), and the generated electrical energy is used to charge the power battery. The power split mechanism 104 also transmits another portion of the driving force to the gearbox input shaft 107 through the output terminal, and the gearbox input shaft 107 transmits this portion of the driving force to the front axle of the vehicle in sequence through the second synchronizer 106, the gearbox output shaft 108, and the front axle differential 109 to drive the vehicle. The distribution ratio of driving force can be set according to actual needs. That is, in the power split mode, 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.

[0086] In pure electric four-wheel drive mode, engine 101 is off, clutch 102 is open, first synchronizer 105 is engaged, second synchronizer 106 is in gear, and both first motor 103 and second motor are in drive mode. At this time, the power battery simultaneously supplies power to both motors. The driving force output by the first motor 103 is transmitted to the power split mechanism 104 through the second input terminal. The power split mechanism 104 then transmits the driving force to the front axle wheels through the output terminal, transmission input shaft 107, second synchronizer 106, transmission output shaft 108, and front axle differential 109. The driving force output by the second motor is transmitted to the rear axle wheels through the rear axle differential.

[0087] When the vehicle switches from power-split mode to pure electric four-wheel drive mode, clutch 102 needs to be disengaged, engine 101 needs to be shut off, and the first synchronizer 105 needs to be controlled to shift gears, so that the first motor 103 switches from generating state to driving state. Because multiple components of the vehicle's front axle need to be controlled during the mode switching process, the mode switching chain is relatively long, which can easily lead to problems such as long mode switching time or even mode switching failure, thus affecting the user's driving experience during the mode switching process.

[0088] To address the current challenge of achieving rapid and stable switching from power-split mode to pure electric four-wheel drive mode in hybrid vehicles, this application aims to provide a vehicle mode switching method. By adjusting the torque of the engine 101 and the first motor 103 when the vehicle meets the mode switching conditions for switching from power-split mode to pure electric four-wheel drive mode, the clutch 102 can be quickly disengaged, and the engine 101 can be stopped. Then, by adjusting the speed of the first motor 103 while the clutch 102 is open, the first synchronizer 105 can be quickly closed while ensuring safe gear shifting. This effectively improves the mode switching speed and enhances the user's driving experience while ensuring smooth switching.

[0089] Reference Figure 2 This application illustrates a vehicle mode switching method applicable to a hybrid vehicle employing the aforementioned architecture. The method may include the following steps:

[0090] S201: When the vehicle meets the mode switching conditions from power split mode to pure electric four-wheel drive mode, the torque of the engine 101 and the first motor 103 is adjusted so that the clutch 102 meets the opening conditions.

[0091] It should be noted that the executing entity in this embodiment can be a computing service device with data processing, network communication, and program execution functions, or an electronic device with the above functions, such as a vehicle computer, an onboard computer, or an ECU (Electronic Control Unit) or HCU (Hybrid Control Unit). This embodiment will use an HCU as the executing entity for explanation. It should be noted that this embodiment does not impose specific limitations on the executing entity of the vehicle.

[0092] In this embodiment, because the engine 101 can drive the first motor 103 to charge the power battery when the power battery's charge is low in the power split mode, the remaining charge of the power battery will continuously increase as the vehicle travels. Specifically, the HCU can determine that the vehicle meets the mode switching conditions for switching from the power split mode to the pure electric four-wheel drive mode when it detects that the current remaining charge of the power battery is greater than a charge threshold, thus achieving automatic switching from the power split mode to the pure electric four-wheel drive mode.

[0093] In this embodiment, considering that some users prefer to use the vehicle's pure electric four-wheel drive mode, the HCU can also control the vehicle to switch from power-split mode to pure electric four-wheel drive mode when it detects the user's intention to use pure electric four-wheel drive mode. Specifically, the user can transmit a mode switching command to enter pure electric four-wheel drive mode to the HCU by directly issuing a voice command, triggering a pre-configured physical button, or triggering a virtual button on the display screen. The HCU then responds to the mode switching command and determines that the vehicle meets the mode switching conditions for switching from power-split mode to pure electric four-wheel drive mode.

[0094] In this embodiment, after determining that the vehicle meets the mode switching conditions, the HCU will control the clutch 102 to open, thereby cutting off the power output of the engine 101.

[0095] In the specific implementation, considering that in the power split mode, the engine 101 drives the first motor 103 to generate electricity sequentially through the clutch 102 and the power split mechanism 104, the torques of the engine 101 and the first motor 103 will act together on the clutch 102. Therefore, the HCU will simultaneously adjust the torque of the engine 101 and the first motor 103 so that the torque applied to the clutch 102 by the engine 101 and the first motor 103 can meet the opening conditions of the clutch 102, thereby achieving rapid opening of the clutch 102 while ensuring its safety.

[0096] In a specific implementation, after the HCU detects that the vehicle meets the mode switching conditions, 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; and 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.

[0097] S202: When the clutch 102 meets the opening conditions, control the clutch 102 to switch from the closed state to the open state, and control the engine 101 to stop.

[0098] In the specific implementation, after determining that the clutch 102 meets the opening conditions, the HCU will send a clutch opening request to the transmission controller, so that the transmission controller responds to the clutch opening request and controls the clutch 102 to open; and when the clutch 102 is open, it will send an engine shutdown request to the engine controller, so that the engine controller responds to the engine shutdown request and controls the engine 101 to shut down.

[0099] S203: When the clutch 102 is in the open state, the speed of the first motor 103 is adjusted so that the first synchronizer 105 meets the gear switching conditions.

[0100] In this embodiment, after the HCU detects that the clutch 102 is in the open state, it sends a motor speed adjustment request to the motor controller, so that the motor controller responds to the motor speed adjustment request and adjusts the speed of the first motor 103.

[0101] In this embodiment, while sending a motor speed control request containing the target motor speed to the motor controller, the HCU also sends a speed control flag bit to the motor controller, so that the motor controller responds to the speed control flag bit and controls the first motor 103 to switch from torque control mode to speed control mode, so as to achieve precise control of the speed of the first motor 103.

[0102] In this embodiment, during the process of HCU adjusting the speed of the first motor 103, the speed difference between the two ends of the first synchronizer 105 is calculated in real time, and then the first synchronizer 105 is determined to meet the gear switching condition when the speed difference is less than the speed difference threshold.

[0103] In this embodiment, by adjusting the speed of the first motor 103, the fast response speed and high adjustment accuracy of the first motor 103 can be utilized to quickly balance the speed difference between the two ends of the first synchronizer 105, thereby enabling the first synchronizer 105 to quickly meet the gear switching conditions.

[0104] In this embodiment, by first controlling the clutch 102 to open and controlling the engine 101 to stop, the HCU only needs to control the first motor 103 to adjust the speed, so that the first synchronizer 105 can meet the gear switching conditions without adjusting the speed of the engine 101, thereby improving the efficiency and accuracy of speed adjustment.

[0105] S204: When the first synchronizer 105 meets the gear shifting conditions, control the first synchronizer 105 to switch from the power split gear to the engagement gear, so that the vehicle switches from the power split mode to the pure electric four-wheel drive mode.

[0106] In a specific implementation, after the HCU detects that the first synchronizer 105 meets the gear shifting conditions, it will send a gear shifting request 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 power split gear to the engagement gear.

[0107] It should be noted that after the HCU detects that the vehicle has completed the mode switch, it will control the output torque of the first motor 103 and the second motor according to the torque distribution strategy in the pure electric four-wheel drive mode.

[0108] In this embodiment, by adjusting the torque of the engine 101 and the first motor 103 when the vehicle meets the mode switching conditions from power split mode to pure electric four-wheel drive mode, the clutch 102 can be quickly opened. Furthermore, by adjusting the speed of the first motor 103, the first synchronizer 105 can be quickly closed while ensuring safe gear shifting. Thus, by clearly defining the operational logic of multiple components such as the clutch 102, engine 101, first motor 103, and first synchronizer 105 during mode switching, the mode switching speed can be effectively improved while ensuring smooth switching, thereby enhancing the user's driving experience.

[0109] In one feasible implementation, the step of torque adjustment of engine 101 and first motor 103 in S201 may specifically include the following sub-steps:

[0110] S201-1: Based on the preset target torque, adjust the current motor torque of the first motor 103, and determine the target engine torque of the engine 101 based on the current motor torque.

[0111] In this embodiment, after the HCU detects that the vehicle meets the mode switching conditions, in order to ensure precise adjustment of the motor torque, it sends a torque control flag to the motor controller, so that the motor controller controls the first motor 103 to switch to torque control mode based on the torque control flag, thereby achieving precise control of the motor torque.

[0112] In practical implementation, to ensure the stability of torque regulation, the motor controller can control the current motor torque of the first motor 103 to gradually reach the target torque according to a preset torque regulation gradient. The torque regulation gradient represents the change in torque per unit time, and can be set to, for example, 100 N·m / s.

[0113] In this embodiment, by gradually reducing the current motor torque of the first motor 103 according to the torque adjustment gradient, it is possible to achieve motor torque adjustment while effectively avoiding excessive torque changes that could affect vehicle stability. It should be noted that if the target torque is greater than or equal to zero, the first motor 103 gradually reaches the target torque from a negative torque.

[0114] It should be noted that the target torque represents the torque at which the clutch 102 can open under load. Specifically, this target torque can be set according to the actual safety requirements of the clutch 102. For example, to improve the service life of the clutch 102, the target torque can be set to zero; or to maximize the shift speed, the target torque can be set to the maximum torque that the clutch 102 can handle; or the target torque can be set to a torque between zero and the maximum torque, thereby improving the opening speed to a certain extent while ensuring the service life of the clutch 102.

[0115] In this embodiment, during the process of the motor controller adjusting the current motor torque of the first motor 103, the HCU will calculate the target engine torque of the engine 101 in real time based on the current motor torque, so that the engine 101 can change with the change of motor torque.

[0116] S201-2: Adjust the current engine torque of engine 101 based on the target engine torque.

[0117] It should be noted that, since the engine torque changes in accordance with the motor torque, as the motor controller gradually increases the current motor torque of the first motor 103 from negative torque to the target torque according to the torque adjustment gradient, the current engine torque of the engine 101 will synchronously decrease from positive torque to the target torque. This ensures that the torques acting on the clutch 102 by the engine 101 and the first motor 103 remain in a relatively balanced state, thereby preventing damage to the clutch 102 due to inconsistent torque.

[0118] In one feasible implementation, the vehicle mode switching method may further include the following steps:

[0119] S301: During the torque adjustment of the engine 101 and the first motor 103, the compensation torque of the second motor is determined.

[0120] In this embodiment, considering that the front axle torque will continuously decrease during the torque adjustment of the engine 101 and the first motor 103, the second motor will be used for torque compensation to ensure the power demand of the vehicle during mode switching.

[0121] In this embodiment, since the first motor 103 outputs negative torque to offset part of the positive torque output by the engine 101 in the power split mode, the HCU can determine the sum of the original engine torque and the original motor torque as the compensation torque of the second motor. Here, the original motor torque refers to the motor torque before torque adjustment of the first motor 103, and the original engine torque refers to the engine torque before torque adjustment of the engine 101.

[0122] For example, before the torque adjustment of the engine 101 and the first motor 103 is performed, if the original engine torque is 800 N·m and the original motor torque is -300 N·m, then the compensation torque of the second motor is 500 N·m.

[0123] S302: Based on the compensation torque, torque compensation is performed on the current drive torque of the second motor.

[0124] In this embodiment, the HCU will further add compensation torque to the current driving torque of the second motor to determine the target driving torque of the second motor; then, during the torque adjustment of the engine 101 and the first motor 103, the HCU will control the second motor to gradually increase from the current driving torque to the target driving torque so that the second motor can supplement the torque reduced by the front axle of the vehicle at the rear axle of the vehicle.

[0125] In this embodiment, while adjusting the torque 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.

[0126] In one 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 800 N·m, the first motor 103 outputs -300 N·m, and the second motor outputs 400 N·m, it will respond to the mode switching request by controlling 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, controlling the first motor 103 to gradually increase from -300 N·m to 0 N·m, and simultaneously controlling the second motor to gradually increase from 400 N·m to 900 N·m.

[0127] In this embodiment, torque compensation is performed by a second motor, so that the vehicle's power performance remains consistent during mode switching, thereby effectively meeting the driver's power needs during mode switching and preventing abnormal deceleration or jerking of the vehicle.

[0128] In one feasible implementation, continue to refer to Figure 1 The power splitting 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 serves as the first input end of the power splitting mechanism 104 and is connected to the engine 101. The sun gear 1042 serves as the second input end of the power splitting mechanism 104 and is connected to the first motor 103. The ring gear 1041 serves as the output end of the power splitting mechanism 104 and is connected to the gearbox input shaft 107. The first synchronizer 105 is disposed between the planet carrier 1044 and the ring gear 1041.

[0129] In power split mode, the first synchronizer 105 is in power split gear. At this time, the planetary carrier 1044 and the ring gear 1041 are disengaged, and the clutch 102 is engaged. The driving force output by the engine 101 is transmitted to the planetary carrier 1044 through the clutch 102. The planetary carrier 1044 then transmits a portion of the driving force to the first motor 103 through multiple planetary gears 1043 and the sun gear 1042 to drive the first motor 103 to charge the power battery. The first motor 103 is in generator mode at this time. At the same time, since the second synchronizer 106 is in gear, the planetary carrier 1044 transmits another portion of the driving force to the front axle of the vehicle through multiple planetary gears 1043, the ring gear 1041, the gearbox input shaft 107, the second synchronizer 106, the gearbox output shaft 108, and the front axle differential 109 to drive the vehicle.

[0130] In pure electric four-wheel drive mode, the engine 101 is off, the clutch 102 is open, the first synchronizer 105 is engaged, the second synchronizer 106 is in gear, and both the first motor 103 and the second motor are in drive mode. At this time, the power battery supplies power to both the first motor 103 and the second motor simultaneously. The driving force output by the first motor 103 is transmitted to the front axle of the vehicle in sequence through the sun gear 1042, planetary gears 1043, ring gear 1041, transmission input shaft 107, second synchronizer 106, transmission output shaft 108, and front axle differential 109 to drive the vehicle.

[0131] Based on the above structure, the step in S201-1 of determining the target engine torque of engine 101 based on the current motor torque may specifically include the following sub-steps:

[0132] S201-1-1: When the current gear of the first synchronizer 105 is the power split gear, the gear ratio between the planetary carrier 1044 and the sun gear 1042 is determined to be the first gear ratio.

[0133] In this embodiment, considering that the gear ratio between the planetary carrier 1044 and the ring gear 1041 is different in different gears of the first synchronizer 105, wherein when the current gear of the first synchronizer 105 is the power split gear, the gear ratio between the planetary carrier 1044 and the ring gear 1041 is the third gear ratio, and then combined with the fourth gear ratio between the ring gear 1041 and the sun gear 1042, the gear ratio between the planetary carrier 1044 and the sun gear 1042 can be calculated as the first gear ratio.

[0134] In practical implementation, the first gear ratio can be calculated using the following formula:

[0135] i1 = i3 × i4 (1);

[0136] Where i1 represents the first gear ratio between the planet carrier 1044 and the sun gear 1042, i3 represents the fourth gear ratio between the planet carrier 1044 and the ring gear 1041 when the first synchronizer 105 is in the power split gear, and i4 represents the fourth gear ratio between the ring gear 1041 and the sun gear 1042.

[0137] S201-1-2: Based on the current motor torque and the first gear ratio, determine the target engine torque of engine 101.

[0138] In practical implementation, after calculating the first gear ratio, the HCU can calculate the target engine torque of engine 101 according to the following formula:

[0139] T = T0 × i1 (2);

[0140] Where T represents the target engine torque of engine 101; T0 represents the current motor torque of first motor 103; and i1 represents the first gear ratio between planetary carrier 1044 and sun gear 1042.

[0141] In this embodiment, by comprehensively considering the current gear of the first synchronizer 105 and the gear ratio between the first motor 103 and the engine 101, the target engine torque can be accurately calculated, thereby ensuring that the clutch 102 can be smoothly closed.

[0142] In one feasible implementation, the vehicle mode switching method may further include the following steps:

[0143] S401: When the current motor torque is less than the first torque threshold and the current engine torque is less than the second torque threshold, trigger a timer for the duration of the state.

[0144] In this embodiment, considering that torque fluctuations may occur in both the engine 101 and the first motor 103 during the torque adjustment process, the torque fluctuations of the engine 101 and the first motor 103 will be detected in order to smoothly achieve the opening operation of the clutch 102, so as to determine whether the engine 101 and the first motor 103 are in a stable operating state at the same time.

[0145] In its implementation, if the HCU detects that the current engine torque is less than a first torque threshold and the current motor torque is less than a second torque threshold, it will trigger a timer for the duration of operation. The duration of operation represents the length of time that the engine 101 and the first motor 103 have been running stably.

[0146] It should be noted that the torque threshold can be set according to the torque control accuracy of the engine 101 and the first motor 103. The more accurate the torque control accuracy, the smaller the torque threshold can be set. For example, if the torque control accuracy of the engine 101 is poor, the first torque threshold can be set to 3 N·m; if the torque control accuracy of the first motor 103 is high, the second torque threshold can be set to 5 N·m.

[0147] S402: If the duration of the state is greater than the duration threshold, determine that the clutch 102 meets the opening condition.

[0148] In this embodiment, if the HCU detects a duration exceeding a duration threshold, it indicates that both the engine 101 and the first motor 103 are fluctuating slightly near the target torque, meaning that the torques of both the engine 101 and the first motor 103 are in a stable state. The duration threshold can be set to 50ms for both.

[0149] In this embodiment, by monitoring the current motor torque and the current engine torque during the torque adjustment of the engine 101 and the first motor 103, it is possible to accurately determine whether the clutch 102 meets the opening conditions, thereby ensuring that the clutch 102 can be opened smoothly and effectively avoiding damage to the clutch 102 and failure to open.

[0150] In one feasible implementation, the step of adjusting the speed of the first motor 103 in S203 may specifically include the following sub-steps:

[0151] S203-1: Determine the second gear ratio between the first motor 103 and the target wheel based on the current gear position of the first synchronizer 105 and the second synchronizer 106.

[0152] In this embodiment, considering that the current gear of the second synchronizer 106 remains unchanged and is always in gear during mode switching, the gear ratio between the transmission input shaft 107 and the transmission output shaft 108 is determined by the current gear of the second synchronizer 106; that is, different gears of the second synchronizer 106 correspond to different gear ratios. Furthermore, combining the gear ratio corresponding to the current gear of the second synchronizer 106 and the fixed gear ratio between the transmission output shaft 108 and the target wheel, the fifth gear ratio between the transmission input shaft 107 and the target wheel can be calculated.

[0153] It should be noted that the target wheel refers to the wheel located on the same side as the first motor 103. For example, when the first motor 103, engine 101, and transmission are located on the front axle of the vehicle, the target wheel refers to the front axle wheel. The current wheel speed can be determined based on the speed signal collected by the wheel speed sensor; it can also be determined based on the current vehicle speed. For example, the current wheel speed of the target wheel can be determined based on the ratio of the current vehicle speed to the wheel circumference.

[0154] In this embodiment, considering that the gear ratio between the ring gear 1041 and the sun gear 1042 is the fourth gear ratio when the current gear of the first synchronizer 105 is the power split gear, and since the ring gear 1041 and the gearbox input shaft 107 rotate at the same speed, the second gear ratio between the sun gear 1042 and the target wheel can be calculated by comprehensively considering the current gears of the first synchronizer 105 and the second synchronizer 106.

[0155] In practical implementation, the second gear ratio can be calculated using the following formula:

[0156] i2 = i4 × i5 (3);

[0157] Where i2 represents the second gear ratio between the sun gear 1042 and the target wheel, i4 represents the fourth gear ratio between the ring gear 1041 and the sun gear 1042, and i5 represents the fifth gear ratio between the gearbox input shaft 107 and the target wheel.

[0158] S203-2: Determine the target motor speed of the first motor 103 based on the current wheel speed of the target wheel and the second gear ratio.

[0159] In practical implementation, after calculating the second gear ratio, the HCU can calculate the target motor speed according to the following formula:

[0160] n = n0 × i2 (4);

[0161] Where n represents the target motor speed of the first motor 103, n0 represents the current wheel speed of the target wheel, and i2 represents the second gear ratio between the sun gear 1042 and the target wheel.

[0162] S203-3: Control the current motor speed of the first motor 103 to follow the target motor speed.

[0163] In this embodiment, while sending a motor speed adjustment request containing the target motor speed to the motor controller, the HCU also sends a speed control flag bit to the motor controller, so that the motor controller controls the first motor 103 to switch from torque control mode to speed control mode, so as to achieve precise control of the speed of the first motor 103.

[0164] In this embodiment, after receiving a motor speed adjustment request and switching to speed control mode, the motor controller will activate the PI (proportional-integral) speed loop for the first motor 103 to control the current motor speed of the first motor 103 to follow the target motor speed through closed-loop control.

[0165] In practical implementation, a preset PI control strategy can be used to achieve closed-loop control of the motor speed. Specifically, the motor controller has a built-in proportional controller and an integral controller. The motor controller first calculates the first speed difference between the target motor speed and the current motor speed, and then inputs the current motor speed and the first speed difference into the proportional controller to output a proportional control value; the current motor speed and the first speed difference are input into the integral controller to output an integral control value; and then, based on the proportional control value and the integral control value, the speed of the first motor 103 is adjusted.

[0166] It should be noted that since the target motor speed of the first motor 103 is determined based on the current wheel speed of the target wheel, the speed difference across the first synchronizer 105 can be equivalent to the speed difference between the current wheel speed of the first motor 103 and the target motor speed. Therefore, it is unnecessary to detect the speeds at both ends of the first synchronizer 105 separately; monitoring only the current wheel speed of the first motor 103 is sufficient to determine whether the first synchronizer 105 meets the gear shifting conditions.

[0167] Specifically, if the speed difference between the current wheel speed of the first motor 103 and the target motor speed is less than the speed difference threshold, it can be determined that the first synchronizer 105 meets the gear switching condition.

[0168] In this embodiment, by comprehensively considering the current wheel speed of the target wheel and the current gear of the first synchronizer 105 and the second synchronizer 106, the target motor speed can be accurately calculated. At the same time, by performing closed-loop control on the motor speed, the current motor speed can be quickly and accurately controlled, thereby effectively balancing the speed difference between the two ends of the first synchronizer 105. Under the premise of ensuring the safe shifting of the first synchronizer 105, the gear switching of the first synchronizer 105 can be quickly switched.

[0169] In one feasible implementation, S204 may specifically include the following sub-steps:

[0170] S204-1: When the first synchronizer 105 meets the gear switching conditions, the first motor 103 is controlled to follow the preset gear shifting auxiliary torque to assist the first synchronizer 105 in switching from the power split gear to the engagement gear.

[0171] In this embodiment, considering that the first synchronizer 105 needs to switch from the disengaged state to the locked state when switching from the power shunt mode to the engaged mode, a small shift assist torque is output by the first motor 103 during the mode switching process, so that the first motor 103 can assist the first synchronizer 105 in smoothly completing the shifting operation. The shift assist torque can be set to 2 N·m.

[0172] In a specific implementation, the HCU sends a second motor torque adjustment request, which includes the shift assist torque, to the motor controller, so that the motor controller responds to the second motor torque adjustment request and adjusts the torque of the first motor 103, so that the first motor 103 outputs the shift assist torque.

[0173] In this embodiment, by controlling the output of the first motor 103 to provide gear shifting assistance torque, the first synchronizer 105, under the auxiliary drive of the first motor 103, effectively avoids the phenomenon of gear shifting failure and improves the gear shifting efficiency of the first motor 103.

[0174] Secondly, based on the same inventive concept, and referring to... Figure 3 This 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 splitting 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 splitting mechanism 104 via the clutch 102. The first motor 103 is connected to the second input end of the power splitting mechanism 104. The output end of the power splitting 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 device 300 includes:

[0175] The torque adjustment module 301 is used to adjust the torque of the engine 101 and the first motor 103 when the vehicle meets the mode switching conditions for switching from power split mode to pure electric four-wheel drive mode, so that the clutch 102 meets the opening conditions.

[0176] The clutch control module 302 is used to control the clutch 102 to switch from the closed state to the open state and to control the engine 101 to stop when the clutch 102 meets the opening conditions.

[0177] The speed adjustment module 303 is used to adjust the speed of the first motor 103 when the clutch 102 is in the open state, so that the first synchronizer 105 can meet the gear switching conditions.

[0178] The gear shifting module 304 is used to control the first synchronizer 105 to switch from the power split gear to the engagement gear when the first synchronizer 105 meets the gear shifting conditions, so that the vehicle switches from the power split mode to the pure electric four-wheel drive mode.

[0179] In one embodiment of this application, the vehicle mode switching device 300 further includes:

[0180] The switching condition determination module is used to determine whether the vehicle meets the mode switching conditions for switching from power split mode to pure electric four-wheel drive mode in response to a mode switching command triggered by the user, or when the current remaining charge of the high-voltage battery is greater than the charge threshold.

[0181] In one embodiment of this application, the torque adjustment module 301 includes:

[0182] The motor torque adjustment submodule is used to adjust the current motor torque of the first motor 103 based on a preset target torque, and to determine the target engine torque of the engine 101 based on the current motor torque.

[0183] The engine torque adjustment submodule is used to adjust the current engine torque of engine 101 based on the target engine torque.

[0184] In one embodiment of this application, the vehicle further includes a second motor, and the vehicle mode switching device 300 further includes:

[0185] The torque determination module is used to determine the compensation torque of the second motor during the torque adjustment of the engine 101 and the first motor 103.

[0186] The torque compensation module is used to compensate the current drive torque of the second motor based on the compensation torque.

[0187] In one embodiment of this 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 a first input end, the sun gear 1042 is connected to the first motor 103 as a second input end, the ring gear 1041 is connected to the gearbox input shaft 107 as an output end, and a first synchronizer 105 is disposed between the planet carrier 1044 and the ring gear 1041;

[0188] The motor torque regulation submodule includes:

[0189] The gear ratio determination unit is used to determine the gear ratio between the planet carrier 1044 and the sun gear 1042 as the first gear ratio when the current gear of the first synchronizer 105 is the power split gear.

[0190] The engine torque determination unit is used to determine the target engine torque of engine 101 based on the current motor torque and the first gear ratio.

[0191] In one embodiment of this application, the vehicle mode switching device 300 further includes:

[0192] The timing module is used to trigger a timer for the duration of the state when the current motor torque is less than a first torque threshold and the current engine torque is less than a second torque threshold.

[0193] The opening condition determination module is used to determine that the clutch 102 meets the opening condition when the duration of the state is greater than the duration threshold.

[0194] In one embodiment of this application, the gearbox further includes a second synchronizer 106 and a gearbox output shaft 108, the second synchronizer 106 being disposed between the gearbox input shaft 107 and the gearbox output shaft 108; the speed regulation module 303 includes:

[0195] The gear ratio determination submodule is used to determine the second gear ratio between the first motor 103 and the target wheel based on the current gear position of the first synchronizer 105 and the second synchronizer 106.

[0196] The motor speed determination submodule is used to determine the target motor speed of the first motor 103 based on the current wheel speed of the target wheel and the second gear ratio.

[0197] The motor speed control submodule is used to control the current motor speed of the first motor 103 to follow the target motor speed.

[0198] In one embodiment of this application, the gear shifting module 304 includes:

[0199] The auxiliary submodule is used to control the first motor 103 to follow the preset gear shifting torque when the first synchronizer 105 meets the gear shifting conditions, so as to assist the first synchronizer 105 in switching from the power split gear to the engagement gear.

[0200] It should be noted that the specific implementation of the vehicle mode switching device 300 in this application embodiment refers to the specific implementation of the vehicle mode switching method proposed in the first aspect of the above-mentioned application embodiment, and will not be repeated here.

[0201] Thirdly, based on the same inventive concept, and referring to... Figure 4 This 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 splitting 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 splitting mechanism 104 via the clutch 102. The first motor 103 is connected to the second input end of the power splitting mechanism 104. The output end of the power splitting 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.

[0202] The vehicle controller 401 is used to send an engine torque adjustment request to the engine controller 404 and a motor torque adjustment request to the motor controller 403 when the vehicle meets the mode switching conditions for switching from power split mode to pure electric four-wheel drive mode.

[0203] Engine controller 404 is used to adjust the torque of engine 101 in response to an engine torque adjustment request;

[0204] The motor controller 403 is used to adjust the torque of the first motor 103 in response to a motor torque adjustment request;

[0205] The vehicle controller 401 is also used to send a clutch opening request to the transmission controller 402 when the clutch 102 meets the opening conditions; and to send an engine shutdown request to the engine controller 404 when the clutch 102 is open.

[0206] The transmission controller 402 is used to control the clutch 102 to open in response to a clutch opening request;

[0207] The engine controller 404 is also used to control the engine 101 to stop in response to an engine stop request;

[0208] The vehicle controller 401 is also used to send a motor speed adjustment request to the motor controller 403 when the clutch 102 is in the open state.

[0209] The motor controller 403 is also used to adjust the speed of the first motor 103 in response to a motor speed adjustment request so that the first synchronizer 105 meets the gear switching conditions.

[0210] The vehicle controller 401 is also used to send a gear shifting request to the transmission controller 402 when the first synchronizer 105 meets the gear shifting conditions.

[0211] The transmission controller 402 is also used to control the first synchronizer 105 to switch from the power split gear to the engagement gear in response to a gear shift request, so that the vehicle switches from the power split mode to the pure electric four-wheel drive mode.

[0212] It should be noted that the specific implementation of the vehicle mode switching system 400 in this application embodiment refers to the specific implementation of the vehicle mode switching method proposed in the first aspect of the above-mentioned application embodiment, and will not be repeated here.

[0213] Fourthly, based on the same inventive concept, referring to Figure 5 This application provides a vehicle 500, including the vehicle mode switching system 400 proposed in the third aspect of this application.

[0214] It should be noted that the specific implementation of the vehicle 500 in this application embodiment refers to the specific implementation of the vehicle mode switching system 400 proposed in the third aspect of the above-mentioned application embodiment, and will not be repeated here.

[0215] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, apparatus, or computer program products. Therefore, embodiments of the present invention can take the form of entirely hardware embodiments, entirely software embodiments, or embodiments combining software and hardware aspects. Furthermore, embodiments of the present invention can take the form of computer program products 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.

[0216] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, terminal devices (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing terminal device to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing terminal device, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0217] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing terminal device to operate in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0218] These computer program instructions can also be loaded onto a computer or other programmable data processing terminal equipment, causing a series of operational steps to be performed on the computer or other programmable terminal equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable terminal equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0219] Although preferred embodiments of the present invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of the embodiments of the present invention.

[0220] Finally, it should be noted that in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or terminal device that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or terminal device. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or terminal device that includes the element.

[0221] The present invention has provided a detailed description of a vehicle mode switching method, system, and vehicle. Specific examples have been used to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of the present invention. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of the present invention. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A vehicle mode switching method characterized by, 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 via the clutch; the first motor is connected to a second input end of the power split mechanism; the output end of the power split mechanism is connected to the gearbox input shaft; the first synchronizer is disposed between the first input end and the output end; the method includes: When the vehicle meets the mode switching conditions for switching from power split mode to pure electric four-wheel drive mode, the torque of the engine and the first motor is adjusted so that the clutch meets the opening conditions. When the clutch meets the opening condition, control the clutch to switch from the closed state to the open state, and control the engine to stop; When the clutch is in the open state, the speed of the first motor is adjusted so that the first synchronizer meets the gear switching conditions; When the first synchronizer meets the gear switching conditions, the first synchronizer is controlled to switch from the power split gear to the engagement gear, so that the vehicle switches from the power split mode to the pure electric four-wheel drive mode.

2. The vehicle mode switching method according to claim 1, characterized in that, The method further includes: In response to a user-triggered mode switching command, or when the current remaining charge of the high-voltage battery is greater than a charge threshold, the vehicle is determined to meet the mode switching conditions for switching from power split mode to pure electric four-wheel drive mode.

3. The vehicle mode switching method according to claim 1, characterized in that, Torque regulation of the engine and the first motor includes: Based on the preset target torque, the current motor torque of the first motor is adjusted, and based on the current motor torque, the target engine torque of the engine is determined. Based on the target engine torque, the current engine torque of the engine is adjusted.

4. The vehicle mode switching method according to claim 3, characterized in that, The vehicle also includes a second motor, and the method further includes: During the torque adjustment of the engine and the first motor, the compensation torque of the second motor is determined; Based on the compensation torque, torque compensation is performed on the current driving torque of the second motor.

5. The vehicle mode switching method according to claim 3, characterized in that, The power splitting 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 gearbox input shaft as the output end, and the first synchronizer is disposed between the planet carrier and the ring gear; Based on the current motor torque, the target engine torque of the engine is determined, including: When the current gear of the first synchronizer is the power shunt gear, the gear ratio between the planet carrier and the sun gear is determined to be the first gear ratio. Based on the current motor torque and the first gear ratio, the target engine torque of the engine is determined.

6. The vehicle mode switching method according to claim 3, characterized in that, The method further includes: When the current motor torque is less than a first torque threshold and the current engine torque is less than a second torque threshold, a timer is triggered to determine the duration of the state. If the duration of the state is greater than a duration threshold, it is determined that the clutch meets the opening condition.

7. The vehicle mode switching method according to claim 1, characterized in that, The gearbox also includes a second synchronizer and a gearbox output shaft, wherein the second synchronizer is disposed between the gearbox input shaft and the gearbox output shaft; Adjusting the speed of the first motor includes: Based on the current gear position of the first synchronizer and the second synchronizer, determine the second gear ratio between the first motor and the target wheel; Based on the current wheel speed of the target wheel and the second gear ratio, the target motor speed of the first motor is determined; Control the current motor speed of the first motor to follow the target motor speed.

8. The vehicle mode switching method according to claim 1, characterized in that, When the first synchronizer meets the gear switching conditions, controlling the first synchronizer to switch from the power shunt gear to the engagement gear includes: When the first synchronizer meets the gear switching conditions, the first motor is controlled to follow the preset gear shifting auxiliary torque to assist the first synchronizer in switching from the power shunt gear to the engagement gear.

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 split mechanism, a first synchronizer, and a gearbox input shaft; the engine is connected to a first input end of the power split mechanism via the clutch; the first motor is connected to a second input end of the power split mechanism; the output end of the power split mechanism is connected to the gearbox input shaft; 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; wherein... The vehicle controller is used to send an engine torque adjustment request to the engine controller and a motor torque adjustment request to the motor controller when the vehicle meets the mode switching conditions for switching from power split mode to pure electric four-wheel drive mode. The engine controller is configured to adjust the engine torque in response to the engine torque adjustment request; The motor controller is configured to adjust the torque of the first motor in response to the motor torque adjustment request; The vehicle controller is also configured to send a clutch opening request to the transmission controller when the clutch meets the opening conditions; and to send an engine shutdown request to the engine controller when the clutch is open. The transmission controller is configured to control the clutch to open in response to the clutch opening request; The engine controller is also configured to control the engine to shut down in response to the engine shutdown request; The vehicle controller is also used to send a motor speed adjustment request to the motor controller when the clutch is in the open state; The motor controller is further configured to adjust the speed of the first motor in response to the motor speed adjustment request, so that the first synchronizer meets the gear switching conditions; The vehicle controller is further configured to send a gear shifting request to the transmission controller when the first synchronizer meets the gear shifting conditions. The transmission controller is also configured to, in response to the gear shift request, control the first synchronizer to switch from the power split gear to the engagement gear, so that the vehicle switches from the power split mode to the pure electric four-wheel drive mode.

10. A vehicle, characterized in that, Includes the vehicle mode switching system as described in claim 9.

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