Vehicle mode switching method, device, system, vehicle, computer program, and readable medium

Abstract

A vehicle mode switching method, a device, a system, a vehicle, a computer program, and a readable medium, relating to the technical field of vehicle control. When a second synchronizer (106) is in a reverse gear, in response to a mode switching request of switching from a power split mode to a series mode, a clutch (102) is kept in an engaged state, a first motor (103) is kept in a power generation state, and torque adjustment is performed on an engine (101), such that when the second synchronizer (106) satisfies a first gear shifting condition, the second synchronizer (106) can be controlled to shift from the reverse gear to a neutral gear; and rotating speed adjustment is performed on the first motor (103), such that a first synchronizer (105) switches from the power split mode to an engaged mode. According to the present application, gear shifting operations of the second synchronizer (106) and the first synchronizer (105) can be sequentially completed while the clutch (102) is not disengaged and the first motor (103) is kept in the power generation state, thereby effectively shortening a mode switching duration while satisfying the charging requirements of a power battery, and improving dynamic response of a vehicle during mode switching.

Description

Vehicle mode switching method, device, system, vehicle, computer program and readable medium

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on December 29, 2023, with application number 202311864305.2 and entitled “A Vehicle Mode Switching Method, Device, System and Vehicle,” the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of vehicle control technology, and in particular to a vehicle mode switching method, device, system, vehicle, computer program, and computer-readable medium. Background Art

[0003] With the rapid development of the automotive industry and in response to national policies on energy conservation, emission reduction, and carbon neutrality, traditional fuel vehicles are gradually transitioning to hybrid vehicles. To adapt to varying road conditions and driving requirements, hybrid vehicles typically feature multiple driving modes, including direct drive and power split. During driving, these modes switch between each other under certain conditions, depending on road conditions and driving requirements.

[0004] In the prior art, when a vehicle switches from power-split mode to series mode while in reverse, it is typically necessary to first open the clutch, then reduce the engine's torque and adjust the engine's speed. After these operations are complete, the clutch is re-engaged to complete the mode switch. However, due to the clutch opening and closing process, this method not only prevents the engine from driving the motor to charge the power battery after the clutch is opened, but also results in a prolonged mode switch time and untimely engine power response, which in turn affects the vehicle's power response performance during the mode switch. Summary of the Invention

[0005] The embodiments of this application disclose the following technical solutions:

[0006] In a first aspect, an embodiment of the present application provides a vehicle mode switching method, wherein the vehicle includes an engine, a clutch, a first motor, and a gearbox, the gearbox including a power split mechanism, a gearbox input shaft, a gearbox output shaft, a first synchronizer, and a second synchronizer, the engine being connected to a first input end of the power split mechanism via the clutch, the first motor being connected to a second input end of the power split mechanism, the output end of the power split mechanism being connected to the gearbox input shaft, the second synchronizer being disposed between the gearbox input shaft and the gearbox output shaft, and the first synchronizer being disposed between the first input end and the output end; the method comprising:

[0007] When the second synchronizer is in reverse gear, in response to a mode switch request from a power split mode to a series mode, the clutch is kept in a closed state, the first motor is in a generating state, and the engine torque is adjusted so that the second synchronizer meets a first gear switch condition;

[0008] When the second synchronizer satisfies the first gear shifting condition, controlling the second synchronizer to shift from the reverse gear to the neutral gear; and adjusting the speed of the first motor so that the first synchronizer satisfies the second gear shifting condition;

[0009] When the first synchronizer satisfies the second gear switching condition, 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 series mode.

[0010] In some embodiments of the present application, the power split mechanism includes a ring gear, a sun gear, a plurality of planetary gears meshed between the ring gear and the sun gear, and a planetary carrier rotatably connected to the plurality of planetary gears; the planetary 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 planetary carrier and the ring gear;

[0011] The step of adjusting the torque of the engine comprises:

[0012] When the current gear position of the first synchronizer is the power split gear, determining the speed ratio between the sun gear and the planet carrier to be a first speed ratio;

[0013] determining a target engine torque of the engine based on a current motor torque of the first motor and the first speed ratio;

[0014] Based on a preset torque adjustment gradient, the current engine torque of the engine is controlled to be gradually reduced to the target engine torque.

[0015] In some embodiments of the present application, the vehicle further includes a second motor, and the method further includes:

[0016] determining a compensation torque for the second electric machine based on the current engine torque and the current electric machine torque;

[0017] determining a target driving torque of the second motor based on the compensation torque and a current driving torque of the second motor;

[0018] During the process of torque regulation of the engine, the second motor is controlled to gradually increase from the current driving torque to the target driving torque based on the torque regulation gradient.

[0019] In some embodiments of the present application, the method further comprises:

[0020] When a torque difference between the current engine torque of the engine and the target engine torque is less than a torque threshold, triggering timing of a duration during which the torque difference is less than the torque threshold;

[0021] When the duration is greater than a duration threshold, it is determined that the second synchronizer satisfies the first gear shift condition.

[0022] In some embodiments of the present application, the step of adjusting the speed of the first motor includes:

[0023] determining a target motor speed of the first motor based on a current engine speed of the engine and the first speed ratio;

[0024] The current motor speed of the first motor is controlled to follow the target motor speed.

[0025] In some embodiments of the present application, the method further comprises:

[0026] determining a current ring gear speed of the ring gear based on the current motor speed and a second speed ratio between the ring gear and the sun gear;

[0027] determining a current planet carrier speed of the planet carrier based on the current engine speed;

[0028] In a case where a speed difference between the current ring gear speed and the current planet carrier speed is less than a speed difference threshold, it is determined that the first synchronizer meets the second gear shift condition.

[0029] In some embodiments of the present application, the step of controlling the first synchronizer to switch from the power split gear to the engagement gear so as to switch the vehicle from the power split mode to the series mode includes:

[0030] When the first synchronizer satisfies the second gear shift condition, the sum of the current motor torque of the first motor and the preset gear-up assist torque is determined as the target motor torque;

[0031] The current motor torque of the first motor is controlled to follow the target motor torque to assist the first synchronizer in shifting from the power split gear to the engagement gear.

[0032] In a second aspect, based on the same inventive concept, an embodiment of the present application provides a vehicle mode switching device, the vehicle comprising an engine, a clutch, a first motor, and a gearbox; the gearbox comprising a power split mechanism, a gearbox input shaft, a gearbox output shaft, a first synchronizer, and a second synchronizer; 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 second synchronizer is disposed between the gearbox input shaft and the gearbox output shaft, and the first synchronizer is disposed between the first input end and the output end; the device comprises:

[0033] a torque regulation module, configured to, in response to a mode switching request from a power split mode to a series mode when the second synchronizer is in a reverse gear, maintain the clutch in a closed state, the first motor in a generating state, and perform torque regulation on the engine so that the second synchronizer satisfies a first gear switching condition;

[0034] a speed regulating module, configured to control the second synchronizer to switch from the reverse gear to the neutral gear when the second synchronizer satisfies the first gear switching condition; and to regulate the speed of the first motor so that the first synchronizer satisfies the second gear switching condition;

[0035] The mode switching module is configured to control the first synchronizer to switch from the power split gear to the engagement gear when the first synchronizer satisfies the second gear switching condition, so as to switch the vehicle from the power split mode to the series mode.

[0036] In some embodiments of the present application, the power split mechanism includes a ring gear, a sun gear, a plurality of planetary gears meshed between the ring gear and the sun gear, and a planetary carrier rotatably connected to the plurality of planetary gears; the planetary 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 planetary carrier and the ring gear;

[0037] The torque adjustment module includes:

[0038] a speed ratio determining submodule, configured to determine, when the current gear position of the first synchronizer is the power split gear, that the speed ratio between the sun gear and the planet carrier is a first speed ratio;

[0039] an engine torque determination submodule, configured to determine a target engine torque of the engine based on a current motor torque of the first motor and the first speed ratio;

[0040] The engine torque control submodule 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.

[0041] In some embodiments of the present application, the vehicle mode switching device further includes:

[0042] a compensation torque determination module, configured to determine a compensation torque of the second motor based on the current engine torque and the current motor torque;

[0043] a driving torque determination module, configured to determine a target driving torque of the second motor based on the compensation torque and a current driving torque of the second motor;

[0044] A driving torque control module is configured to control the second motor to gradually increase the current driving torque to the target driving torque based on the torque adjustment gradient during torque adjustment of the engine.

[0045] In some embodiments of the present application, the vehicle mode switching device further includes:

[0046] a timing module, configured to, when a torque difference between the current engine torque of the engine and the target engine torque is less than a torque threshold, trigger timing of a duration during which the torque difference is less than the torque threshold;

[0047] The first condition determination module is configured to determine that the second synchronizer satisfies the first gear switching condition when the duration is greater than a duration threshold.

[0048] In some embodiments of the present application, the speed adjustment module includes:

[0049] a motor speed determination submodule, configured to determine a target motor speed of the first motor based on a current engine speed of the engine and the first speed ratio;

[0050] The motor speed control submodule is used to control the current motor speed of the first motor to follow the target motor speed.

[0051] In some embodiments of the present application, the vehicle mode switching device further includes:

[0052] a ring gear speed determining module, configured to determine a current ring gear speed of the ring gear based on the current motor speed and a second speed ratio between the ring gear and the sun gear;

[0053] a planet carrier speed determination module, configured to determine a current planet carrier speed of the planet carrier based on the current engine speed;

[0054] The second condition determination module is configured to determine that the first synchronizer satisfies the second gear shift condition when a speed difference between the current ring gear speed and the current planet carrier speed is less than a speed difference threshold.

[0055] In some embodiments of the present application, the mode switching module includes:

[0056] a motor torque determination submodule, configured to determine, when the first synchronizer satisfies the second gear shift condition, a sum of the current motor torque of the first motor and a preset gear-up assist torque as a target motor torque;

[0057] The gear shift submodule is configured to control the current motor torque of the first motor to follow the target motor torque, so as to assist the first synchronizer in shifting from the power split gear to the engagement gear.

[0058] In a third aspect, based on the same inventive concept, an embodiment of the present application provides a vehicle mode switching system, wherein the vehicle includes an engine, a clutch, a first motor and a gearbox; the gearbox includes a power split mechanism, a gearbox input shaft, a gearbox output shaft, a first synchronizer and a second synchronizer; the engine is connected to the first input end of the power split mechanism through the clutch, the first motor is connected to the second input end of the power split mechanism, the output end of the power split mechanism is connected to the gearbox input shaft, the second synchronizer is arranged between the gearbox input shaft and the gearbox output 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,

[0059] the vehicle controller is configured to, in response to a mode switch request from a power split mode to a series mode when the second synchronizer is in reverse gear, send an engine torque adjustment request to the engine controller, send a clutch state holding request to the transmission controller, and send a motor state holding request to the motor controller;

[0060] The transmission controller is configured to maintain the clutch in a closed state in response to the clutch state maintaining request; the motor controller is configured to maintain the first motor in a power generation state in response to the motor state maintaining request;

[0061] The engine controller is configured to adjust the engine torque in response to the engine torque adjustment request so that the second synchronizer satisfies a first gear shift condition;

[0062] The vehicle controller is further configured to send a first gear shift request to the transmission controller and a motor speed adjustment request to the motor controller when the second synchronizer satisfies the first gear shift condition;

[0063] The transmission controller is further configured to control the second synchronizer to shift from the reverse gear to the neutral gear in response to the first gear shift request; 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 second gear shift condition;

[0064] The vehicle controller is further configured to send a second gear shift request to the transmission controller when the first synchronizer satisfies the second gear shift condition;

[0065] The transmission controller is further configured to control the first synchronizer to shift from the power split gear to an engagement gear in response to the second shift request, so as to switch the vehicle from the power split mode to the series mode.

[0066] 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.

[0067] In a fifth aspect, an embodiment of the present application provides a computer program comprising a computer-readable code, which, when executed on a computing and processing device, causes the computing and processing device to execute the vehicle mode switching method according to any one of the first aspects.

[0068] In a sixth aspect, an embodiment of the present application provides a computer-readable medium in which the computer program described in the fifth aspect is stored.

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

[0070] A vehicle mode switching method provided in an embodiment of the present application can, when the second synchronizer is in reverse gear, respond to a mode switching request to switch from a power split mode to a series mode, keep the clutch in a closed state, the first motor in a power generation state, and adjust the engine torque so that when the second synchronizer meets the first gear switching condition, the second synchronizer can be controlled to switch from the reverse gear to the neutral gear; and by adjusting the speed of the first motor, when the first synchronizer meets the second gear switching condition, the first synchronizer can be controlled to switch from the power split gear to the engagement gear, so that the vehicle can switch from the power split mode to the series mode. The embodiment of the present application adjusts the torque of the engine and then adjusts the speed of the first motor, so that during the vehicle mode switching process, the shifting operations of the second synchronizer and the first synchronizer can be completed in sequence without opening the clutch and keeping the first motor generating electricity. In this way, the engine can not only continue to drive the first motor to charge the power battery, but also enable the vehicle to switch from the power split mode to the series mode more quickly and smoothly when reversing. While meeting the charging needs of the power battery, it effectively shortens the mode switching time, enables the engine to quickly output torque, and improves the vehicle's power response performance during the mode switching process.

[0071] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0072] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, a brief introduction will be given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0073] FIG1 is a schematic structural diagram of a hybrid vehicle in an embodiment of the present application.

[0074] FIG2 is a flowchart of the steps of a vehicle mode switching method in an embodiment of the present application.

[0075] FIG3 is a schematic diagram of functional modules of a vehicle mode switching device in an embodiment of the present application.

[0076] FIG4 is a schematic structural diagram of a vehicle mode switching system in an embodiment of the present application.

[0077] FIG5 is a schematic structural diagram of a vehicle in an embodiment of the present application.

[0078] FIG6 is a block diagram schematically illustrating a computing and processing device for executing the method according to the present application in an embodiment of the present application; and

[0079] FIG7 schematically illustrates a storage unit for storing or carrying program codes for implementing the method according to the present application in an embodiment of the present application. Specific embodiments

[0080] To make the purpose, technical solutions, and advantages of the embodiments of this application more clear, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0081] 1 , which shows a schematic structural diagram of a hybrid vehicle in an embodiment of the present application. 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 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 a first input end of the power splitting mechanism 104 via the clutch 102, the first motor 103 is connected to a 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.

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

[0083] The first synchronizer 105 is arranged between the first input end and the output end, and is used to connect or disconnect the first input end and the output end. Specifically, when the first synchronizer 105 is in the engagement gear, the first synchronizer 105 is used to connect the first input end and the output end; when the first synchronizer 105 is in the power diversion gear, the first synchronizer 105 is used to disconnect 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 diversion mode and other modes, that is, when the first synchronizer 105 is in the power diversion gear, the vehicle can be in the power diversion mode; when the first synchronizer 105 is in the engagement gear, the vehicle can be in other modes other than the power diversion mode, for example, the series mode, the direct drive mode or the pure electric four-wheel drive mode.

[0084] Furthermore, the gearbox output shaft 108 is also connected to the front axle wheels through the 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 the rear axle differential (not shown in the figure) to drive the rear axle of the vehicle.

[0085] The hybrid vehicle using the above architecture is 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 have multiple driving modes, including a series mode and a power split mode. Furthermore, by changing the gear position of the first synchronizer 105 and the second synchronizer 106, the vehicle can switch between different driving modes. Specifically:

[0086] In the power split mode, the first synchronizer 105 is in the power split gear. At this time, the first synchronizer is in the disengaged state, used to disconnect the first input terminal and the output terminal, the second synchronizer 106 is in the gear state, the engine 101 is in the driving state, the clutch 102 is in the closed 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 (the first motor 103 outputs negative torque at this time), 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 through the output terminal to the transmission input shaft 107, which is then transmitted by the transmission input shaft 107 to the front axle of the vehicle through the second synchronizer 106, the transmission output shaft 108 and the front axle differential 109 in sequence to drive the vehicle. Among them, the distribution ratio of driving force can be set according to actual needs. That is, in the power diversion 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.

[0087] In series mode, the first synchronizer 105 is in the engaged gear. At this point, the first synchronizer 105 is used to connect the first input and output terminals, the second synchronizer 106 is in neutral, the engine 101 is in a driving state, the clutch 102 is in a closed state, the first motor 103 is in a generating state, and the second motor is in a driving state. At this point, because the second synchronizer 106 is in neutral, the driving force output by the engine 101 will not be transmitted to the transmission input shaft 107 via the first input terminal, the first synchronizer 105, and the output terminal. Instead, the driving force output by the engine 101 will be transmitted to the power splitter mechanism 104 via the first input terminal. The power splitter mechanism 104 then transmits the entire driving force to the first motor 103 via the second input terminal, driving the first motor 103 to generate electricity. The generated electrical energy is then provided to the second motor to drive the vehicle. It should be noted that because the driving force of the engine 101 in series mode is entirely used to drive the first motor 103 to generate electricity, the charging power of the power battery in series mode is generally greater than that in power split mode.

[0088] In related art, after a hybrid vehicle completes reverse in power-split mode, it is necessary to switch the vehicle from power-split mode to series mode. However, in conventional vehicle mode switching strategies, the vehicle must first disengage clutch 104, then perform torque reduction and speed regulation on engine 101. After the torque reduction and speed regulation are completed, clutch 104 is re-engaged to complete the mode switch. However, due to the process of opening and closing clutch 104, this approach not only results in the engine 101 being unable to drive the first motor 103 to charge the power battery after the clutch 104 is opened, but also results in a longer mode switch time and untimely power response from engine 101, thereby affecting the vehicle's power response performance during the mode switch process.

[0089] In response to the problem that current hybrid vehicles interrupt power battery charging and have poor vehicle power response performance when switching from power split mode to series mode in reverse, the present application aims to provide a vehicle mode switching method, device, system, vehicle, computer program and computer-readable medium, which can keep the clutch 102 in a closed state and the first motor 103 in a power generation state, and by adjusting the torque of the engine 101 and then adjusting the speed of the first motor 103, during the vehicle mode switching process, the second synchronizer 106 and the first synchronizer 105 can be completed in sequence without opening the clutch 102. In this way, the engine 101 can not only continue to drive the first motor 103 to charge the power battery, but also enable the vehicle to switch from power split mode to series mode more quickly and smoothly in reverse, while meeting the charging needs of the power battery, effectively shortening the mode switching time, allowing the engine 101 to quickly output torque, and improving the vehicle's power response performance during the mode switching process.

[0090] 2 , a vehicle mode switching method according to the present application is shown. The method is applied to a hybrid vehicle using the above-mentioned architecture. The method may include the following steps:

[0091] S201: When the second synchronizer 106 is in the reverse gear, in response to a mode switching request from the power split mode to the series mode, the clutch 102 is kept in a closed state, the first motor 103 is in a power generation state, and the engine 101 is torque-regulated so that the second synchronizer 106 meets the first gear switching condition.

[0092] It should be noted that the execution entity of 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 driving computer, an onboard computer, etc., such as an ECU (Electronic Control Unit), a BCM (Body Control Module), or an HCU (Vehicle Control Unit). This embodiment will be described using the HCU as the execution entity. It should be noted that this implementation does not impose specific restrictions on the execution entity of the vehicle.

[0093] In this embodiment, when the second synchronizer 106 is in the reverse gear, that is, the vehicle is in the reverse state, the HCU can monitor by obtaining the vehicle's gear lever information and the SOC (State of Charge, battery state of charge, also known as the remaining power) of the power battery to determine whether the vehicle needs to switch from the power split mode to the series mode.

[0094] In the specific implementation, if the HCU detects that the current remaining power of the power battery is less than the power threshold and the gear lever information indicates that the gear lever position has been switched from R gear (reverse gear) to P gear (parking gear) or N gear (neutral gear), it means that the power battery needs to be charged and the driver intends to end reversing. At this time, in order to avoid power battery depletion, the vehicle will automatically trigger a mode switching request from power diversion mode to series mode.

[0095] In this embodiment, the HCU will send a clutch state maintaining request to the transmission controller in response to the mode switching request, so that the transmission controller keeps the clutch 102 in the closed state in response to the clutch state maintaining request; at the same time, it will send a motor state maintaining request to the motor controller, so that the motor controller keeps the first motor 103 in the power generation state in response to the motor state maintaining request, that is, keeps the original power generation torque unchanged; at the same time, it will send an engine torque adjustment request to the engine controller, so that the engine controller adjusts the torque of the engine 101 in response to the engine torque adjustment request.

[0096] It should be noted that the second synchronizer 106 is disposed between the transmission input shaft 107 and the transmission output shaft 108. When in gear, it enables torque transmission between the transmission input shaft 107 and the transmission output shaft 108; when in neutral, it disconnects torque transmission between the transmission input shaft 107 and the transmission output shaft 108. When the vehicle is in power-split mode, the second synchronizer 106 is in reverse gear. At this point, a portion of the driving force output by the engine 101 can be transmitted to the front axle wheels via the second synchronizer 106. At this point, the reverse gear is reversed, enabling the vehicle to reverse. When the vehicle switches from power-split mode to series mode, the second synchronizer 106 must be shifted to neutral. Consequently, the driving force output by the engine 101 no longer directly drives the vehicle, but is instead used entirely to drive the first motor 103 for power generation.

[0097] In this embodiment, to prevent the second synchronizer 106 from being unable to disengage or being damaged during disengagement, the HCU adjusts the torque applied to the second synchronizer 106 to a smaller value, ideally zero.

[0098] In this embodiment, considering that when the clutch 102 is closed, the torques of the engine 101 and the first motor 103 can be simultaneously applied to the second synchronizer 106 via the power splitting mechanism 104, by adjusting the torque of the engine 101, it is possible to effectively balance the torques acting on the second synchronizer 106 by the engine 101 and the first motor 103 while maintaining the output torque of the first motor 103 unchanged, thereby achieving torque adjustment of the second synchronizer 106. In this way, the torque at the second synchronizer 106 can be reduced to the torque required for closing the second synchronizer 106 without opening the clutch 102 and interrupting the power generation of the first motor 103, so that the second synchronizer 106 meets the first gear shift condition.

[0099] In an example, if the HCU detects that the engine 101 outputs 800 N·m to the power splitting mechanism 104 and the first motor 103 outputs -300 N·m to the power splitting mechanism 104, it will control the first motor 103 to continue to output -300 N·m for generating electricity, and control the current engine torque of the engine 101 to be reduced from 800 N·m to 300 N·m. In this way, not only can the gear switching requirements of the second synchronizer 106 be met, but also the first motor 103 can be kept in the generating state.

[0100] S202 : When the second synchronizer 106 meets the first gear shifting condition, the second synchronizer 106 is controlled to shift from the reverse gear to the neutral gear; and the speed of the first motor 103 is adjusted so that the first synchronizer 105 meets the second gear shifting condition.

[0101] In this embodiment, after the HCU detects that the second synchronizer 106 meets the first gear shifting condition and the current gear is in the gear state, it will send a first gear shifting request indicating that the target gear is neutral to the transmission controller, so that the transmission controller responds to the first gear shifting request and controls the second synchronizer 106 to shift from the reverse gear to the neutral gear.

[0102] In this embodiment, if the HCU detects that the second synchronizer 106 has switched to neutral, it will trigger the speed adjustment of the first motor 103 and send a motor speed adjustment request including the target motor speed to the motor controller, so that the motor controller responds to the motor speed adjustment request and adjusts the current motor speed of the first motor 103 so that the first synchronizer 105 meets the second gear switching condition.

[0103] It should be noted that the first synchronizer 105 is arranged between the first input end and the output end of the power splitting mechanism 104. Since the output end is connected to the transmission input shaft 107, the first synchronizer 105 can be used to adjust the speed ratio between the first input end of the power splitting mechanism 104 and the transmission input shaft 107.

[0104] In power-split mode, the first synchronizer 105 is in the power-split gear. At this point, the speed ratio between the power-split mechanism 104 and the transmission input shaft 107 is typically set to a value greater than 1, such as 2:1. When the vehicle switches from power-split mode to series mode, the first synchronizer 105 must be engaged. At this point, the first input and output ends of the power-split mechanism 104 are locked, while the output end is connected to the transmission input shaft 107, resulting in a 1:1 speed ratio between the first input end and the transmission input shaft 107. To prevent damage to the first synchronizer 105 when engaging a gear, the speed difference between the two ends of the first synchronizer 105 must be minimal, ideally zero.

[0105] In this embodiment, considering that the first motor 103 is connected to the power splitting mechanism 104, and the torque balance at the first synchronizer 105 has been achieved through the engine 101 and the first motor 103, therefore, by adjusting the speed of the first motor 103, it is also possible to adjust the speed of both ends of the first synchronizer 105 while continuing to keep the clutch 102 closed, so that the first synchronizer 105 meets the second gear switching condition.

[0106] S203 : When the first synchronizer 105 meets the second gear switching condition, the first synchronizer 105 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 series mode.

[0107] In this embodiment, after the HCU detects that the first synchronizer 105 meets the second gear switching condition and the current gear is the power split gear, it will send a second gear switching request indicating that the target gear is the engagement gear to the transmission controller, so that the transmission controller responds to the second gear switching request and controls the second synchronizer 106 to switch from the power split gear to the neutral gear.

[0108] In this embodiment, after the HCU determines that the first synchronizer 105 has switched to the engagement gear, it will set the current driving mode of the vehicle from the power split mode to the series mode, and then adjust the speed of the engine 101 and the first motor 103 according to the speed control strategy in the series mode, so that the engine 101 drives the first motor 103 to generate electricity stably.

[0109] Specifically, the HCU will execute a preset speed control strategy, controlling the current engine speed of engine 101 to increase or decrease to a preset first target power generation speed, and simultaneously controlling the current motor speed of first motor 103 to increase or decrease to a preset second target power generation speed. The first target power generation speed represents the engine speed that enables engine 101 to operate within its optimal operating range and meet the charging requirements of first motor 103; the second target power generation speed represents the motor speed that enables first motor 103 to stably output the target power generation voltage. This allows the driving force output by engine 101 to be transmitted to first motor 103 via power splitter 104, driving first motor 103 to generate stable power.

[0110] In this embodiment, the HCU also executes a preset energy management strategy to determine a first energy allocation ratio for the power battery and a second energy allocation ratio for the second motor based on the current SOC of the power battery and the power demand triggered by the driver. The HCU then controls the first motor 103 to charge the power battery according to the first energy allocation ratio and controls the first motor 103 to power the second motor according to the second energy allocation ratio. Specifically, the first energy allocation ratio can be set to decrease as the current SOC increases, and the first energy allocation ratio can be reduced to zero when the current SOC reaches a preset charging cut-off threshold.

[0111] By adjusting the torque of the engine 101, the embodiment of the present application can achieve the shifting operation of the second synchronizer 106 while maintaining the first motor 103 in the power generation state. By adjusting the speed of the first motor 103, the shifting operation of the first synchronizer 105 can be achieved without disengaging the clutch 102. This allows the vehicle to switch from power split mode to series mode more quickly and smoothly when reversing. On the one hand, the engine 101 can not only continuously drive the first motor 103 to charge the power battery, meeting the power battery charging requirements; on the other hand, it can effectively shorten the mode switching time, allowing the engine 101 to quickly output torque, and improving the vehicle's dynamic response performance during the mode switching process.

[0112] For example, continuing to refer to Figure 1, the power splitting mechanism 104 may specifically include a ring gear 1041, a sun gear 1042, a plurality of planetary gears 1043 meshed between the ring gear 1041 and the sun gear 1042, and a planetary carrier 1044 rotatably connected to the plurality of planetary gears 1043; the planetary 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 gearbox input shaft 107 as the output end of the power splitting mechanism 104, and the first synchronizer 105 is arranged between the planetary carrier 1044 and the ring gear 1041.

[0113] In series mode, the first synchronizer 105 is in the engaged gear and the second synchronizer 106 is in neutral. At this point, the planetary carrier 1044 and the ring gear 1041 are locked. Since the second synchronizer 106 is in neutral, the driving force transmitted from the engine 101 to the planetary carrier 1044 via the clutch 102 is not transmitted to the transmission output shaft 108 via the first synchronizer 105, the ring gear 1041, or the transmission input shaft 107. Instead, it is transmitted to the first motor 103 via the plurality of planetary gears 1043 and the sun gear 1042 in sequence, driving the first motor 103 to generate electricity. The generated electricity is then supplied to the second motor to drive the vehicle.

[0114] In the power split mode, the first synchronizer 105 is in the power split gear. At this time, the planetary carrier 1044 and the ring gear 1041 are in the disconnected state. The driving force output by the engine 101 will be transmitted to the planetary carrier 1044 through the clutch 102, and the planetary carrier 1044 will transmit part of the driving force to the first motor 103 through multiple planetary 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 planetary carrier 1044 will transmit another part 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 in sequence to drive the vehicle to move.

[0115] Based on the above structure, the step of adjusting the torque of the engine 101 in step S201 may specifically include the following sub-steps:

[0116] S201 - 1 : When the current gear position of the first synchronizer 105 is the power split gear, the speed ratio between the sun gear 1042 and the planet carrier 1044 is determined to be the first speed ratio.

[0117] It should be noted that since the first synchronizer 105 has different gears, the planetary carrier 1044 and the ring gear 1041 have different speed ratios, and the sun gear 1042 has the same speed as the first motor 103, and the planetary carrier 1044 has the same speed as the engine. Therefore, based on the current gear of the first synchronizer 105, the speed ratio between the first motor 103 and the engine 101 can be determined.

[0118] In this embodiment, since the current gear position of the first synchronizer 105 is the power split gear before the gear shift, the HCU determines that the speed ratio between the sun gear 1042 and the planet carrier 1044 is the first speed ratio.

[0119] S201 - 2 : Determine the target engine torque of the engine 101 based on the current motor torque of the first motor 103 and the first speed ratio.

[0120] In this embodiment, since the speed and torque are inversely proportional, the HCU will control the current motor torque of the first motor 103 to remain unchanged, and based on the first speed ratio and the current motor torque of the first motor 103, the target engine torque of the engine 101 can be inversely calculated.

[0121] S201 - 3 : Based on a preset torque adjustment gradient, control the current engine torque of the engine 101 to gradually decrease to the target engine torque.

[0122] In this embodiment, after determining the target engine torque, the HCU activates 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.

[0123] In a specific implementation, the current engine torque of the engine 101 can be controlled to gradually reach 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.

[0124] In this embodiment, by adjusting the torque of the engine 101 according to the torque adjustment gradient, it is possible to avoid excessive torque changes that may affect the driving stability of the vehicle.

[0125] In one feasible embodiment, the vehicle further includes a second motor, and the vehicle mode switching method may further include the following steps:

[0126] S301 : Determine a compensation torque of a second motor based on a current engine torque and a current motor torque.

[0127] In this embodiment, considering that the front axle torque will continue to decrease during the process of torque regulation of the engine 101, in order to ensure the power demand of the entire vehicle during the mode switching process, torque compensation will be performed through the second motor.

[0128] In this embodiment, since the current motor torque is negative torque and is used to offset a portion of the positive torque of the current engine torque, the HCU may determine the sum of the current engine torque and the current motor torque as the compensation torque of the second motor.

[0129] It should be noted that the current engine torque represents the engine torque before the torque adjustment is performed on the engine 101 ; the current motor torque represents the motor torque before the torque adjustment is performed on the engine 101 .

[0130] For example, before the torque of the engine 101 is adjusted, if 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.

[0131] S302 : Determine a target driving torque of the second motor based on the compensation torque and the current driving torque of the second motor.

[0132] In this embodiment, the HCU will further add a compensation torque on the basis of the current driving torque of the second motor, so that the second motor can supplement the reduced torque of the front axle of the vehicle at the rear axle of the vehicle.

[0133] S303 : During the process of torque regulation of the engine 101 , the second motor is controlled to gradually increase the current driving torque to the target driving torque based on the torque regulation gradient.

[0134] In this embodiment, during the process of performing torque regulation on the engine 101 according to the torque regulation gradient, the HCU will also synchronously control the second motor to perform torque compensation according to the same torque regulation gradient.

[0135] In one example, the torque adjustment gradient is set to 200 N·m / s. If the HCU detects that the engine 101 is outputting 800 N·m, the first motor 103 is outputting -300 N·m, and the second motor is outputting 400 N·m, then in response to the mode switch request, the HCU controls the engine 101 to gradually decrease from 800 N·m to 300 N·m, and simultaneously controls the second motor to gradually increase from 400 N·m to 900 N·m, according to the 200 N·m / s torque adjustment gradient.

[0136] In this embodiment, torque compensation is performed through the second motor so that the vehicle's power performance can remain consistent during mode switching, thereby effectively meeting the driver's power needs during mode switching and avoiding abnormal deceleration or jerking of the vehicle.

[0137] Exemplarily, the vehicle mode switching method may further include the following steps:

[0138] S401 : When the torque difference between the current engine torque of the engine 101 and the target engine torque is smaller than a torque threshold, timing of a duration during which the torque difference is smaller than the torque threshold is triggered.

[0139] In this embodiment, during the process of torque regulation of the engine 101, the HCU will obtain the current engine torque fed back in real time by the engine controller, and then, when it detects that the torque difference between the current engine torque and the target engine torque is less than the torque threshold, the timer is triggered to accumulate timing for the duration, and then based on the duration, it is determined whether the engine 101 is stably operating at the target engine torque.

[0140] S402 : When the duration is greater than the first duration threshold, determine that the second synchronizer 106 meets the first gear shifting condition.

[0141] In this embodiment, if the HCU detects that the duration is greater than the duration threshold, it is considered that the engine 101 is stably running at the target engine torque, and further determines that the second synchronizer 106 meets the first gear shift condition.

[0142] In this embodiment, by monitoring the duration, it is possible to effectively avoid controlling the second synchronizer 106 to perform a gear shifting operation when there is abnormal torque fluctuation in the engine 101, thereby ensuring that the second synchronizer 106 can shift gears smoothly.

[0143] For example, the step of adjusting the speed of the first motor 103 in S202 may specifically include the following sub-steps:

[0144] S202 - 1 : Determine a target motor speed of the first motor 103 based on the current engine speed of the engine 101 and the first speed ratio.

[0145] It should be noted that since the first synchronizer 105 is disposed between the planetary carrier 1044 and the ring gear 1041, the rotational speeds of the planetary carrier 1044 and the ring gear 1041 need to be adjusted so that the speed difference between the two ends of the first synchronizer 105 is less than a preset shift threshold. Furthermore, since the planetary carrier 1044 is connected to the engine 101, the rotational speed of the planetary carrier 1044 can be equivalent to the engine speed. Furthermore, since the ring gear 1041 is connected to the first motor 103 via the plurality of planetary gears 1043 and the sun gear 1042, the rotational speed of the ring gear 1041 can be equivalently converted based on the rotational speed of the first motor 103. Thus, by adjusting the rotational speed of the first motor 103, the rotational speeds of the two ends of the first synchronizer 105 can be adjusted so that the first synchronizer 105 meets the second gear shift condition.

[0146] In this embodiment, the HCU uses the current engine speed of the engine 101 as a speed regulation reference. Thus, the first synchronizer 105 can meet the second gear shift condition by adjusting the speed of the first motor 103 without adjusting the engine speed.

[0147] In a specific implementation, the first speed ratio can be calculated based on the speed ratio between the planetary carrier 1044 and the ring gear 1041 as the first speed ratio and the third speed ratio between the ring gear 1041 and the sun gear 1042, and then based on the current engine speed of the engine 101 and the first speed ratio, the target motor speed of the first motor 103 can be calculated.

[0148] S202 - 2 : Control the current motor speed of the first motor 103 to follow the target motor speed.

[0149] In this embodiment, after calculating the target motor speed, the HCU will send a speed control request containing the target motor speed to the motor controller, and will also send a speed control flag to the motor controller, so that the motor controller controls the first motor 103 to switch from the torque control mode to the speed control mode, so as to achieve precise control of the speed of the first motor 103.

[0150] In this embodiment, after receiving the speed control request and switching to the 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.

[0151] In a specific implementation, a preset PI adjustment 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 will first calculate the first speed difference between the target motor speed and the current motor speed, and then input the current motor speed and the first speed difference into the proportional controller, which can output a proportional adjustment value; input the current motor speed and the first speed difference into the integral controller, which can output an integral adjustment value; and then adjust the speed of the first motor 103 based on the proportional adjustment value and the integral adjustment value.

[0152] In this embodiment, by comprehensively considering the current gear of the first synchronizer 105 and the speed ratio between the first motor 103 and the engine 101, 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 at both ends of the first synchronizer 105, ensuring that the first synchronizer 105 can be smoothly engaged in the target gear.

[0153] Exemplarily, the vehicle mode switching method may further include the following steps:

[0154] S501 : Determine the current ring gear speed of the ring gear 1041 based on the current motor speed and the second speed ratio between the ring gear 1041 and the sun gear 1042 .

[0155] In this embodiment, since the first motor 103 is connected to the sun gear 1042 , the current ring gear speed of the ring gear 1041 can be calculated in real time based on the current motor speed and the second speed ratio between the ring gear 1041 and the sun gear 1042 .

[0156] S502 : Based on the current engine speed, determine the current planet carrier speed of the planet carrier 1044 .

[0157] In this embodiment, since the engine 101 is connected to the planetary carrier 1044, the current engine speed can be directly determined as the current planetary carrier speed.

[0158] S503 : When the speed difference between the current ring gear speed and the current planet carrier speed is less than the speed difference threshold, determine that the first synchronizer 105 meets the second gear shift condition.

[0159] In this embodiment, since the first synchronizer 105 is arranged between the ring gear 1041 and the planetary carrier 1044, the speed difference between the current ring gear speed and the current planetary carrier speed can be calculated to obtain the speed difference at both ends of the first synchronizer 105 in real time. When it is detected that the speed difference is less than the speed difference threshold, it means that the first synchronizer 105 meets the second gear switching condition.

[0160] For example, considering that switching the gear of the first synchronizer 105 when the engine speed decreases may cause the engine 101 to be unable to effectively drive the first motor 103 to generate electricity, the HCU can also determine that the first synchronizer 105 meets the second gear switching condition when it detects that the speed difference is less than the speed difference threshold and the current engine speed is greater than or equal to the speed threshold.

[0161] It should be noted that the speed threshold represents the minimum speed at which the engine 101 can drive the first motor 103 to generate electricity stably. In this way, after the vehicle completes the mode switch, the engine 101 can smoothly drive the first motor 103 to generate electricity.

[0162] In this embodiment, by comprehensively considering the speed difference at both ends of the first synchronizer 105 and the current engine speed of the engine 101, it is possible to ensure the switching safety of the first synchronizer 105 while ensuring that the engine 101 can smoothly drive the first motor 103 to generate electricity after completing the mode switch, thereby effectively avoiding the failure of the mode switch or the inability of the vehicle to stably operate in the series mode after completing the mode switch.

[0163] For example, the step of controlling the first synchronizer 105 to switch from the power split gear to the engagement gear in S203 so as to switch the vehicle from the power split mode to the series mode may specifically include the following sub-steps:

[0164] S203 - 1 : When the first synchronizer 105 satisfies the second gear shift condition, the sum of the current motor torque of the first motor 103 and the preset gear-up assist torque is determined as the target motor torque.

[0165] It should be noted that the current motor torque represents the original motor torque of the first motor 103 , that is, the motor torque before torque adjustment is performed on the engine 101 .

[0166] In this embodiment, considering that the first synchronizer 105 needs to switch from the disengaged state to the locked state when shifting from the power split gear to the engaged gear, the gear-in assist torque is added to the current motor torque to obtain the target motor torque. The first motor 103 is then controlled to output the target motor torque, enabling the first motor 103 to assist the first synchronizer 105 in successfully completing the gear shift. The gear-in assist torque can be set to 2 N·m.

[0167] S203 - 2 : Control the current motor torque of the first motor 103 to follow the target motor torque, so as to assist the first synchronizer 105 in switching from the power split gear to the engagement gear.

[0168] In a specific implementation, the HCU sends a second motor torque adjustment request including the target motor 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 target motor torque.

[0169] In this embodiment, by controlling the first motor 103 to superimpose the gear assist torque, the first synchronizer 105 can be driven assisted by the first motor 103 to improve the gear shifting efficiency while avoiding the gear shifting failure of the first synchronizer 105.

[0170] In a second aspect, based on the same inventive concept, with reference to FIG3 , an embodiment of the present application provides a vehicle mode switching device 300 , wherein 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 gearbox input shaft 107 , a gearbox output shaft 108 , a first synchronizer 105 , and a second synchronizer 106 . The engine 101 is connected to a first input end of the power splitting mechanism 104 via the clutch 102 , the first motor 103 is connected to a 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 second synchronizer 106 is disposed between the gearbox input shaft 107 and the gearbox output shaft 108 , and the first synchronizer 105 is disposed between the first input end and the output end. The vehicle mode switching device 300 includes:

[0171] a torque adjustment module 301 for, in response to a mode switch request from the power split mode to the series mode when the second synchronizer 106 is in the reverse gear, keeping the clutch 102 in a closed state, the first motor 103 in a generating state, and adjusting the torque of the engine 101 so that the second synchronizer 106 meets the first gear switching condition;

[0172] The speed regulating module 302 is configured to control the second synchronizer 106 to switch from reverse gear to neutral gear when the second synchronizer 106 satisfies the first gear shifting condition; and to regulate the speed of the first motor 103 so that the first synchronizer 105 satisfies the second gear shifting condition;

[0173] The mode switching module 303 is configured to control the first synchronizer 105 to switch from the power split gear to the engagement gear when the first synchronizer 105 meets the second gear switching condition, so as to switch the vehicle from the power split mode to the series mode.

[0174] Exemplarily, the power split mechanism 104 includes a ring gear 1041, a sun gear 1042, a plurality of planetary gears 1043 meshed between the ring gear 1041 and the sun gear 1042, and a planetary carrier 1044 rotatably connected to the plurality of planetary gears 1043. The planetary carrier 1044 is connected to the engine 101 as a first input end, the sun gear 1042 is connected to the first motor as a second input end, the ring gear 1041 is connected to the transmission input shaft 107 as an output end, and the first synchronizer 105 is disposed between the planetary carrier 1044 and the ring gear 1041.

[0175] The torque adjustment module 301 includes:

[0176] a speed ratio determination submodule, configured to determine that the speed ratio between the sun gear 1042 and the planet carrier 1044 is the first speed ratio when the current gear position of the first synchronizer 105 is the power split gear;

[0177] an engine torque determination submodule, configured to determine a target engine torque of the engine 101 based on a current motor torque of the first motor 103 and a first gear ratio;

[0178] The engine torque control submodule is configured to control the current engine torque of the engine 101 to gradually decrease to a target engine torque based on a preset torque adjustment gradient.

[0179] Exemplarily, the vehicle mode switching device 300 further includes:

[0180] a compensation torque determination module, configured to determine a compensation torque of the second motor based on a current engine torque and a current motor torque;

[0181] a driving torque determination module for determining a target driving torque of the second motor based on the compensation torque and the current driving torque of the second motor;

[0182] The driving torque control module is configured to control the second motor to gradually increase the current driving torque to the target driving torque based on the torque adjustment gradient during the process of adjusting the torque of the engine 101 .

[0183] Exemplarily, the vehicle mode switching device 300 further includes:

[0184] a timing module, configured to, when a torque difference between the current engine torque of the engine 101 and the target engine torque is less than a torque threshold, trigger timing of a duration during which the torque difference is less than the torque threshold;

[0185] The first condition determination module is configured to determine that the second synchronizer 106 satisfies a first gear shift condition when the duration is greater than a duration threshold.

[0186] In one embodiment of the present application, the speed adjustment module 302 includes:

[0187] a motor speed determination submodule, configured to determine a target motor speed of the first motor 103 based on the current engine speed of the engine 101 and the first gear ratio;

[0188] The motor speed control submodule is used to control the current motor speed of the first motor 103 to follow the target motor speed.

[0189] Exemplarily, the vehicle mode switching device 300 further includes:

[0190] a ring gear speed determination module, configured to determine a current ring gear speed of the ring gear 1041 based on a current motor speed and a second speed ratio between the ring gear 1041 and the sun gear 1042;

[0191] a planet carrier speed determination module, configured to determine a current planet carrier speed of the planet carrier 1044 based on a current engine speed;

[0192] The second condition determination module is configured to determine that the first synchronizer 105 satisfies a second gear shift condition when a speed difference between a current ring gear speed and a current planet carrier speed is less than a speed difference threshold.

[0193] Exemplarily, the mode switching module 303 includes:

[0194] a motor torque determination submodule, configured to determine the sum of the current motor torque of the first motor 103 and the preset shift assist torque as the target motor torque when the first synchronizer 105 satisfies the second gear shift condition;

[0195] The gear shift submodule is configured to control the current motor torque of the first motor 103 to follow the target motor torque, so as to assist the first synchronizer 105 in switching from the power split gear to the engagement gear.

[0196] It should be noted that the specific implementation of the vehicle mode switching device 300 in the embodiment of the present application refers to the specific implementation of the vehicle mode switching method proposed in the first aspect of the embodiment of the present application, and will not be repeated here.

[0197] On the third aspect, based on the same inventive concept, with reference to FIG4 , an embodiment of the present application provides a vehicle mode switching system 400, wherein 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 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, the output end of the power splitting mechanism 104 is connected to the gearbox input shaft 107, the second synchronizer 106 is arranged between the gearbox input shaft 107 and the gearbox output shaft 108, and the first synchronizer 105 is arranged between the first input end and the output end; the system includes a vehicle controller 401, a gearbox controller 402, a motor controller 403 and an engine controller 404.

[0198] The vehicle controller 401 is configured to, in response to a mode switch request from the power split mode to the series mode when the second synchronizer 106 is in the reverse gear, send an engine torque adjustment request to the engine controller 404, send a clutch state maintenance request to the transmission controller 402, and send a motor state maintenance request to the motor controller 403;

[0199] The transmission controller 402 is used to keep the clutch 102 in a closed state in response to the clutch state maintenance request; the motor controller 403 is used to keep the first motor 103 in a power generation state in response to the motor state maintenance request;

[0200] The engine controller 404 is configured to adjust the torque of the engine 101 in response to the engine torque adjustment request so that the second synchronizer 106 satisfies the first gear shift condition;

[0201] The vehicle controller 401 is further configured to send a first gear shift request to the transmission controller 402 and a motor speed adjustment request to the motor controller 403 when the second synchronizer 106 satisfies the first gear shift condition;

[0202] The transmission controller 402 is further configured to control the second synchronizer 106 to switch from reverse gear to neutral gear in response to the first gear shift request; the motor controller 403 is further configured to adjust the speed of the first motor 103 in response to the motor speed adjustment request so that the first synchronizer 105 meets the second gear shift condition;

[0203] The vehicle controller 401 is further configured to send a second gear shift request to the transmission controller 402 when the first synchronizer 105 satisfies the second gear shift condition;

[0204] The transmission controller 402 is further configured to control the first synchronizer 105 to shift from the power split gear to the engagement gear in response to the second gear shift request, so as to switch the vehicle from the power split mode to the series mode.

[0205] It should be noted that the specific implementation of the vehicle mode switching system 400 in the embodiment of the present application refers to the specific implementation of the vehicle mode switching method proposed in the first aspect of the present application, and will not be repeated here.

[0206] In a fourth aspect, based on the same inventive concept, referring to FIG. 5 , an embodiment of the present application provides a vehicle 500 , including the vehicle mode switching system 400 proposed in the third aspect of the present application.

[0207] It should be noted that the specific implementation of the vehicle 500 in the embodiment of the present application refers to the specific implementation of the vehicle mode switching system 400 proposed in the third aspect of the embodiment of the present application, and will not be repeated here.

[0208] The various component embodiments of the present invention can be implemented in hardware, or in software modules running on one or more processors, or in a combination thereof. It should be understood by those skilled in the art that a microprocessor or digital signal processor (DSP) can be used in practice to implement some or all of the functions of some or all of the components in the computing processing equipment according to an embodiment of the present invention. The present invention can also be implemented as a device or apparatus program (e.g., a computer program and a computer program product) for executing a part or all of the methods described herein. Such a program implementing the present invention can be stored on a computer-readable medium, or can have the form of one or more signals. Such a signal can be downloaded from an Internet website, or provided on a carrier signal, or provided in any other form.

[0209] For example, FIG6 illustrates a computing device that can implement the method according to the present invention. The computing device typically includes a processor 1010 and a computer program product or computer-readable medium in the form of a memory 1020. Memory 1020 can be an electronic memory such as flash memory, EEPROM (Electrically Erasable Programmable Read-Only Memory), EPROM, hard disk, or ROM. Memory 1020 has storage space 1030 for program code 1031 for executing any of the method steps described above. For example, storage space 1030 for program code can include individual program codes 1031 for implementing various steps in the method described above. These program codes can be read from or written to one or more computer program products. These computer program products include program code carriers such as hard disks, compact disks (CDs), memory cards, or floppy disks. Such computer program products are typically portable or fixed storage units, as described with reference to FIG7 . This storage unit can have storage segments, storage space, etc. arranged similarly to memory 1020 in the computing device of FIG3X. The program code can, for example, be compressed in a suitable form. Typically, the storage unit includes computer-readable codes 1031 ′, ie, codes that can be read by a processor such as 1010 , which, when executed by a computing device, cause the computing device to perform the steps of the method described above.

[0210] Although preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they become aware of the basic inventive concepts. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the embodiments of the present invention.

[0211] Finally, it should be noted that, in this document, relational terms such as first and second, etc., are used only 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 terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or terminal device that includes a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or terminal device. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of additional identical elements in the process, method, article, or terminal device that includes the element.

[0212] The embodiments of the present application are described above in conjunction with the accompanying drawings, but the present application is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of this application, ordinary technicians in this field can also make many forms without departing from the purpose of this application and the scope of protection of the claims, all of which are protected by this application.

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 transmission input shaft, a transmission output shaft, a first synchronizer, and a second synchronizer. 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, the second synchronizer is disposed between the transmission input shaft and the transmission output shaft, and the first synchronizer is disposed between the first input end and the output end; the method includes: When the second synchronizer is in the reverse gear, in response to a mode switching request to switch from a power split mode to a series mode, keep the clutch in a closed state, keep the first motor in a power generation state, and adjust the torque of the engine so that the second synchronizer meets the first gear shifting condition; When the second synchronizer meets the first gear shifting condition, control the second synchronizer to switch from the reverse gear to the neutral gear; and adjust the speed of the first motor so that the first synchronizer meets the second gear shifting condition; When the first synchronizer meets the second gear shifting condition, control the first synchronizer to switch from the power split gear to the engaged gear, so that the vehicle switches from the power split mode to the series mode.

2. The vehicle mode switching method according to claim 1, characterized in that, 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 step of adjusting the torque of the engine includes: When the current gear of the first synchronizer is the power split gear, determine that the speed ratio between the sun gear and the planet carrier is a first speed ratio; Based on the current motor torque of the first motor and the first speed 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.

3. The vehicle mode switching method according to claim 2, wherein The vehicle further includes a second motor, and the method further includes: Based on the current engine torque and the current motor torque, determine the compensation torque of the second motor; Based on the compensation torque and the current driving torque of the second motor, determine the target driving torque of the second motor; During the process of adjusting the torque of the engine, based on the torque adjustment gradient, control the second motor to gradually increase from the current driving torque to the target driving torque.

4. The vehicle mode switching method according to claim 2, wherein, The method further includes: When the torque difference between the current engine torque and the target engine torque of the engine is less than a torque threshold, trigger timing for the duration during which the torque difference is less than the torque threshold; When the duration is greater than the duration threshold, it is determined that the second synchronizer meets the first gear shifting condition.

5. The vehicle mode switching method according to claim 2, wherein, The step of adjusting the rotational speed of the first motor includes: Based on the current engine speed of the engine and the first gear ratio, determining the target motor speed of the first motor; Controlling the current motor speed of the first motor to follow the target motor speed.

6. The vehicle mode switching method according to claim 5, wherein The method further includes: Based on the current motor speed and the second gear ratio between the ring gear and the sun gear, determining the current ring gear speed of the ring gear; Based on the current engine speed, determining the current carrier speed of the carrier; When the rotational speed difference between the current ring gear speed and the current carrier speed is less than the rotational speed difference threshold, it is determined that the first synchronizer meets the second gear shifting condition.

7. The vehicle mode switching method according to claim 5, wherein, The step of controlling the first synchronizer to switch from the power split gear to the engaged gear, so that the vehicle switches from the power split mode to the series mode includes: When the first synchronizer meets the second gear shifting condition, determining the sum of the current motor torque of the first motor and a preset shift assist torque as the target motor torque; Controlling the current motor torque of the first motor to follow the target motor torque to assist the first synchronizer to switch from the power split gear to the engaged gear.

8. A vehicle mode switching device, characterized in that, The vehicle includes an engine, a clutch, a first motor, and a transmission; the transmission includes a power split mechanism, a transmission input shaft, a transmission output shaft, a first synchronizer, and a second synchronizer. The engine is connected to the first input end of the power split mechanism through the clutch, the first motor is connected to the second input end of the power split mechanism, the output end of the power split mechanism is connected to the transmission input shaft, the second synchronizer is arranged between the transmission input shaft and the transmission output shaft, and the first synchronizer is arranged between the first input end and the output end; the device includes: A torque adjustment module, configured to, when the second synchronizer is in the reverse gear, in response to a mode switching request for switching from the power split mode to the series mode, keep the clutch in a closed state, keep the first motor in a power generation state, and adjust the torque of the engine so that the second synchronizer meets the first gear shifting condition; A rotational speed adjustment module, configured to, when the second synchronizer meets the first gear shifting condition, control the second synchronizer to switch from the reverse gear to the neutral gear; and adjust the rotational speed of the first motor so that the first synchronizer meets the second gear shifting condition; A mode switching module, configured to, when the first synchronizer meets the second gear shifting condition, control the first synchronizer to switch from the power split gear to the engaged gear, so that the vehicle switches from the power split mode to the series mode.

9. A vehicle mode switching system, characterized in that, The vehicle includes an engine, a clutch, a first motor, and a transmission; the transmission includes a power split mechanism, a transmission input shaft, a transmission output shaft, a first synchronizer, and a second synchronizer. 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. The second synchronizer is disposed between the transmission input shaft and the transmission output shaft. The first synchronizer is disposed between the first input end and the output end; the system includes a vehicle controller, a transmission controller, a motor controller, and an engine controller; wherein, the vehicle controller is configured to, when the second synchronizer is in the reverse gear, in response to a mode switching request for switching from a power split mode to a series mode, send an engine torque adjustment request to the engine controller, send a clutch state holding request to the transmission controller, and send a motor state holding request to the motor controller; the transmission controller is configured to, in response to the clutch state holding request, keep the clutch in a closed state; the motor controller is configured to, in response to the motor state holding request, keep the first motor in a power generation state; the engine controller is configured to, in response to the engine torque adjustment request, adjust the torque of the engine so that the second synchronizer meets the first gear shifting condition; the vehicle controller is further configured to, when the second synchronizer meets the first gear shifting condition, send a first gear shifting request to the transmission controller and send a motor speed adjustment request to the motor controller; the transmission controller is further configured to, in response to the first gear shifting request, control the second synchronizer to switch from the reverse gear to the neutral gear; the motor controller is further configured to, in response to the motor speed adjustment request, adjust the speed of the first motor so that the first synchronizer meets the second gear shifting condition; the vehicle controller is further configured to, when the first synchronizer meets the second gear shifting condition, send a second gear shifting request to the transmission controller; the transmission controller is further configured to, in response to the second gear shifting request, control the first synchronizer to switch from the power split gear to the engaged gear, so that the vehicle switches from the power split mode to the series mode.

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

11. A computer program, characterized in that, It includes computer-readable code, which, when running on a computing processing device, causes the computing processing device to execute the vehicle mode switching method according to any one of claims 1-7.

12. A computer-readable medium, characterized in that, Wherein a computer program as described in claim 11 is stored.

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