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

Abstract

A vehicle mode switching method, device (300), and system (400), a vehicle (500), a computer program, and a computer readable medium, relating to the technical field of vehicle control. The method comprises: in response to a mode switching request, keeping a clutch (102) in an engaged state and an engine (101) in a driving state, and performing torque adjustment on a first motor (103), so that when a first synchronizer (105) meets a first gear switching condition, the first synchronizer (105) switches from an engagement gear to a power split gear; and performing rotating speed adjustment on the first motor (103), so that when a second synchronizer (106) meets a second gear switching condition, the second synchronizer (106) can switch from a neutral gear to a target gear. Gear shifting operations of the first synchronizer (105) and the second synchronizer (106) can be sequentially completed without disengaging the clutch (102) and interrupting the torque of the engine (101), so that the engine (101) can also immediately output torque to the wheel end by means of a power split mechanism (104) while continuously driving the first motor (103) to be kept in a power generation state, thereby effectively improving the power response performance of the vehicle (500) during mode switching.

Description

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

[0001] This disclosure claims priority to a Chinese patent application filed with the Patent Office of China on December 29, 2023, with application number 202311866343.1 and invention name “A vehicle mode switching method, device, system and vehicle,” the entire contents of which are incorporated by reference in the disclosure. Technical Field

[0002] The present disclosure 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 series and power-split modes. During driving, these modes switch between each other under certain conditions, depending on road conditions and driving requirements.

[0004] In related technologies, when a vehicle switches from series mode to power-split mode, it is usually necessary to first open the clutch, then reduce the engine torque and adjust the speed. After the torque reduction and speed adjustment are completed, the clutch is re-closed to complete the mode switch. However, this method involves the clutch opening and closing process, which will cause the engine power to be interrupted. This will not only cause the motor to stop generating power, but also lead to long mode switching times and untimely engine power response, which in turn affects the dynamic response performance of the entire vehicle. Summary of the Invention

[0005] The present disclosure provides a vehicle mode switching method, device, system, vehicle, computer program and computer-readable medium to solve the problem of poor vehicle dynamic response performance when hybrid vehicles switch from series mode to power split mode.

[0006] In order to solve the above problems, the present disclosure adopts the following technical solutions:

[0007] In a first aspect, an embodiment of the present disclosure provides a vehicle mode switching method, 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 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 method includes:

[0008] In response to a mode switch request from the series mode to the power split mode, the clutch is kept in a closed state, the engine is in a driving state, and a current motor torque of the first motor is adjusted so that the first synchronizer satisfies a first gear shift condition.

[0009] When the first synchronizer satisfies the first gear shifting condition, controlling the first synchronizer to switch from the engagement gear to the power split gear; and adjusting the current motor speed of the first motor so that the second synchronizer satisfies the second gear shifting condition;

[0010] When the second synchronizer satisfies the second gear switching condition, the second synchronizer is controlled to switch from neutral to a target gear, so that the vehicle switches from the series mode to the power split mode.

[0011] In one embodiment of the present disclosure, 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;

[0012] The step of performing torque adjustment on the current motor torque of the first motor comprises:

[0013] determining a target motor torque for the first motor based on a current engine torque of the engine and a first speed ratio between the sun gear and the planet carrier;

[0014] Based on the target motor torque, torque adjustment is performed on the current motor torque of the first motor.

[0015] In one embodiment of the present disclosure, the method further includes:

[0016] When a first torque difference between the current motor torque and the target motor torque is less than a first torque threshold, triggering timing of a first duration during which the first torque difference is less than the first torque threshold and a second duration during which the fluctuation amplitude of the current engine torque is less than a second torque threshold;

[0017] When the first duration is greater than a first duration threshold, and the second duration is greater than a second duration threshold, it is determined that the first synchronizer meets the first gear shift condition.

[0018] In one embodiment of the present disclosure, the step of adjusting the current motor speed of the first motor includes:

[0019] determining a target motor speed of the first motor based on a current gear position of the first synchronizer and a target gear position of the second synchronizer;

[0020] Based on the target motor speed, the current motor speed of the first motor is adjusted.

[0021] In one embodiment of the present disclosure, the step of determining the target motor speed of the first motor based on the current gear position of the first synchronizer and the target gear position of the second synchronizer includes:

[0022] When the current gear position of the first synchronizer is the power split gear, determining the speed ratio between the planet carrier and the ring gear to be a second speed ratio;

[0023] determining, based on the target gear position of the second synchronizer, a speed ratio between the transmission input shaft and the target wheel as a third speed ratio;

[0024] determining a fourth speed ratio between the target wheel and the first motor based on the second speed ratio, the first speed ratio, and the third speed ratio;

[0025] A target motor speed of the first motor is determined based on the fourth speed ratio and the current wheel speed of the target wheel.

[0026] In one embodiment of the present disclosure, the method further includes:

[0027] When the current motor speed of the first motor reaches the target motor speed, triggering timing of a third duration during which the fluctuation amplitude of the current motor speed is less than a speed threshold;

[0028] When the third duration is greater than a third duration threshold, it is determined that the second synchronizer meets the second gear shift condition.

[0029] In one embodiment of the present disclosure, when the second synchronizer satisfies the second gear shifting condition, the step of controlling the second synchronizer to shift from neutral to the target gear includes:

[0030] When the second synchronizer satisfies the second gear shifting condition, controlling the second synchronizer to perform a pre-synchronization operation so as to move the shift fork of the second synchronizer to a pre-synchronization position;

[0031] When it is determined that the shift fork of the second synchronizer reaches the pre-synchronization position and the first torque difference between the current motor torque and the target motor torque is less than a fourth torque threshold, the second synchronizer is controlled to move from the pre-synchronization position to the target position so that the second synchronizer is switched to the target gear.

[0032] In a second aspect, an embodiment of the present disclosure 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 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 device comprising:

[0033] a torque adjustment module, configured to, in response to a mode switching request from the series mode to the power split mode, maintain the clutch in a closed state, the engine in a driving state, and perform torque adjustment on a current motor torque of the first motor so that the first synchronizer satisfies a first gear shift condition;

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

[0035] The gear switching module is used to control the second synchronizer to switch from neutral to a target gear when the second synchronizer meets the second gear switching condition, so as to switch the vehicle from the series mode to the power split mode.

[0036] In one embodiment of the present disclosure, 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; the torque regulation module includes:

[0037] a target motor torque determination submodule, configured to determine a target motor torque of the first motor based on a current engine torque of the engine and a first speed ratio between the sun gear and the planet carrier;

[0038] The torque adjustment submodule is configured to adjust the current motor torque of the first motor based on the target motor torque.

[0039] In one embodiment of the present disclosure, the vehicle mode switching device further includes:

[0040] a first timing module, configured to trigger, when a first torque difference between the current motor torque and the target motor torque is less than a first torque threshold, timing a first duration during which the first torque difference is less than the first torque threshold and timing a second duration during which the fluctuation amplitude of the current engine torque is less than a second torque threshold;

[0041] The first condition determination module is configured to determine that the first synchronizer satisfies the first gear shift condition when the first duration is greater than a first duration threshold and the second duration is greater than a second duration threshold.

[0042] In one embodiment of the present disclosure, the speed adjustment module includes:

[0043] a target motor speed determination submodule, configured to determine a target motor speed of the first motor based on a current gear position of the first synchronizer and a target gear position of the second synchronizer;

[0044] The speed adjustment submodule is used to adjust the current motor speed of the first motor based on the target motor speed.

[0045] In one embodiment of the present disclosure, the target motor speed determination submodule includes:

[0046] a first speed ratio determining unit, configured to determine, when the current gear position of the first synchronizer is the power split gear, that the speed ratio between the planet carrier and the ring gear is a second speed ratio;

[0047] a second speed ratio determining unit, configured to determine, based on a target gear position of the second synchronizer, a speed ratio between the transmission input shaft and the target wheel as a third speed ratio;

[0048] a third speed ratio determining unit, configured to determine a fourth speed ratio between the target wheel and the first motor based on the second speed ratio, the first speed ratio, and the third speed ratio;

[0049] The target motor speed determining unit is configured to determine a target motor speed of the first motor based on the fourth speed ratio and the current wheel speed of the target wheel.

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

[0051] a second timing module, configured to trigger timing of a third duration during which the fluctuation amplitude of the current motor speed is less than a speed threshold when the current motor speed of the first motor reaches the target motor speed;

[0052] The second condition determination module is configured to determine that the second synchronizer satisfies the second gear shift condition when the third duration is greater than a third duration threshold.

[0053] In one embodiment of the present disclosure, the gear switching module includes:

[0054] a pre-synchronization submodule, configured to control the second synchronizer to perform a pre-synchronization operation when the second synchronizer satisfies the second gear shifting condition, so as to move the shift fork of the second synchronizer to a pre-synchronization position;

[0055] The gear shift submodule is configured to control the second synchronizer to move from the pre-synchronization position to the target position so that the second synchronizer is switched to the target gear when it is determined that the shift fork of the second synchronizer has reached the pre-synchronization position and the first torque difference between the current motor torque and the target motor torque is less than a fourth torque threshold.

[0056] In a third aspect, an embodiment of the present disclosure 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,

[0057] The vehicle controller is configured to, in response to a mode switching request from the series mode to the power split mode, send a clutch state maintaining request to the transmission controller, send an engine state maintaining request to the engine controller, and send a torque adjustment request to the motor controller;

[0058] The transmission controller is configured to maintain the clutch in a closed state in response to the clutch state maintaining request;

[0059] The engine controller is configured to maintain the engine in a driving state in response to the engine state maintaining request;

[0060] The motor controller is configured to perform torque adjustment on a current motor torque of the first motor in response to the torque adjustment request, so that the first synchronizer satisfies a first gear shift condition;

[0061] The vehicle controller is further configured to control the transmission controller to switch the first synchronizer from the engagement gear to the power split gear when the first synchronizer satisfies the first gear switching condition, and to send a speed adjustment request to the motor controller;

[0062] The motor controller is further configured to adjust the current motor speed of the first motor in response to the speed adjustment request so that the second synchronizer satisfies a second gear shift condition;

[0063] The vehicle controller is further configured to control the transmission controller to switch the second synchronizer from neutral to a target gear when the second synchronizer satisfies the second gear switching condition, so as to switch the vehicle from the series mode to the power split mode.

[0064] In a fourth aspect, an embodiment of the present disclosure provides a vehicle, including the vehicle mode switching system proposed in the third aspect of the present disclosure.

[0065] In a fifth aspect, an embodiment of the present disclosure 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 described above.

[0066] In a sixth aspect, an embodiment of the present disclosure provides a computer-readable medium in which the above-mentioned computer program is stored.

[0067] Compared with the prior art, the present disclosure has the following advantages:

[0068] A vehicle mode switching method provided by an embodiment of the present disclosure is capable of responding to a mode switch request from series mode to power-split mode by maintaining a clutch in a closed state and an engine in a driving state, and performing torque regulation on the current motor torque of a first motor so that when a first synchronizer satisfies a first gear shift condition, the first synchronizer is controlled to switch from an engaged gear to a power-split gear. Furthermore, the current motor speed of the first motor is regulated so that when a second synchronizer satisfies a second gear shift condition, the second synchronizer is controlled to switch from a neutral gear to a target gear, thereby switching the vehicle from series mode to power-split mode. By sequentially regulating the torque and speed of the first motor, the present embodiment enables the shifting of the first and second synchronizers to be completed sequentially during the vehicle mode switch process without disengaging the clutch or interrupting the engine torque. In this way, the engine can not only continuously drive the first motor to maintain a generating state through the power-split mechanism to meet the charging requirements of the power battery, but can also immediately output torque to the wheels through the power-split mechanism, enabling the vehicle to switch from series mode to power-split mode more quickly and smoothly, effectively improving the vehicle's dynamic response performance during the mode switch process.

[0069] The above description is only an overview of the technical solution of the present disclosure. In order to more clearly understand the technical means of the present disclosure, 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 disclosure more obvious and easy to understand, the specific implementation methods of the present disclosure are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0070] In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure or related technologies, the following briefly introduces the drawings required for use in the embodiments or related technical descriptions. Obviously, the drawings described below are some embodiments of the present disclosure. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0071] FIG1 is a schematic structural diagram of a hybrid vehicle according to an embodiment of the present disclosure;

[0072] FIG2 is a flowchart of a vehicle mode switching method according to an embodiment of the present disclosure;

[0073] FIG3 is a schematic diagram of functional modules of a vehicle mode switching device according to an embodiment of the present disclosure;

[0074] FIG4 is a schematic structural diagram of a vehicle mode switching system according to an embodiment of the present disclosure;

[0075] FIG5 is a schematic structural diagram of a vehicle according to an embodiment of the present disclosure;

[0076] FIG6 schematically shows a block diagram of a computing processing device for executing the method according to the present disclosure;

[0077] FIG7 schematically shows a storage unit for holding or carrying program codes for implementing the method according to the present disclosure. Specific embodiments

[0078] To make the objectives, technical solutions, and advantages of the embodiments of the present disclosure more clear, the technical solutions in the embodiments of the present disclosure will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present disclosure, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present disclosure without making any creative efforts shall fall within the scope of protection of the present disclosure.

[0079] 1 , which shows a schematic structural diagram of a hybrid vehicle in an embodiment of the present disclosure. 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.

[0080] 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.

[0081] 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.

[0082] 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.

[0083] The hybrid vehicle using the above architecture is equipped with a power split mechanism 104, which is simultaneously 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:

[0084] 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.

[0085] In series mode, the first synchronizer 105 is in the engaged gear. At this time, the first synchronizer 105 is used to connect the first input end and the output end, the second synchronizer 106 is in neutral, 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, 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 through the first input end, the first synchronizer 105 and the output end. The driving force output by the engine 101 will be transmitted to the power splitting mechanism 104 through the first input end, and then the power splitting mechanism 104 will transmit all of the driving force to the first motor 103 through the second input end to drive the first motor 103 to generate electricity, and the generated electricity is provided to the second motor to drive the vehicle.

[0086] In the related art, in order to avoid damage to actuators such as the clutch 102 and synchronizer, when the vehicle switches from the series mode to the power split mode, it is usually necessary for the vehicle to first open the clutch 102, then reduce the torque and adjust the speed of the engine 101, and then re-close the clutch 102 after the torque reduction and speed adjustment operations are completed to complete the mode switch. However, this method involves the process of opening and closing the clutch 102, which will cause the power of the engine 101 to be interrupted. On the one hand, it will cause the first motor 103 to stop generating electricity. The first motor 103 needs to wait until the clutch 102 is fully closed and the engine 101 resumes outputting torque before it can charge the power battery. On the other hand, it will also result in a longer switching link and a longer mode switching time. The engine 101 cannot output power to the wheel end in time, thereby affecting the power response performance of the entire vehicle.

[0087] In view of the problem of poor vehicle dynamic response performance in the process of switching from series mode to power split mode in current hybrid vehicles, the present disclosure aims to provide a vehicle mode switching method, which sequentially adjusts the torque and speed of the first motor 103, so that during the vehicle mode switching process, the shifting operation of the first synchronizer 105 and the second synchronizer 106 can be completed in sequence without opening the clutch 102 and without interrupting the torque of the engine 101. In this way, the engine 101 can not only continuously drive the first motor 103 to maintain the power generation state through the power split mechanism 104 to meet the charging needs of the power battery, but can also immediately output torque to the wheel end through the power split mechanism 104, so that the vehicle can switch from the series mode to the power split mode more quickly and smoothly, effectively improving the vehicle's dynamic response performance during the mode switching process.

[0088] 2 , a vehicle mode switching method according to the present disclosure is shown. The method is applied to a hybrid vehicle using the above-mentioned architecture. The method may include the following steps:

[0089] S201: In response to a mode switching request from series mode to power split mode, the clutch 102 is kept in a closed state, the engine 101 is in a driving state, and the current motor torque of the first motor 103 is torque-adjusted so that the first synchronizer 105 meets the first gear switching condition.

[0090] It should be noted that the execution entity of this embodiment can be a computing service device with data processing, network communication, and program execution functions, or an electronic device with these functions, such as a vehicle computer, an onboard computer, or the like, such as an ECU (Electronic Control Unit) or an HCU (Hybrid 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.

[0091] In this embodiment, the HCU can determine whether the vehicle needs to switch from series mode to power split mode by monitoring the accelerator pedal signal and the SOC (State of Charge, also known as the remaining power) of the power battery, where the accelerator pedal signal may include the accelerator pedal opening and the accelerator pedal change rate.

[0092] In this embodiment, by monitoring the accelerator pedal signal, it can be determined whether the driver has a need for rapid acceleration; by monitoring the current remaining power of the power battery, it can be determined whether the power battery needs to be charged.

[0093] In a specific implementation, the accelerator pedal signal may include the accelerator pedal opening and the accelerator pedal change rate. In this way, if the HCU detects that the current driving mode of the vehicle is series mode, the accelerator pedal opening is greater than the opening threshold, the accelerator pedal change rate is greater than the change rate threshold and the current remaining power of the power battery is less than the power threshold, it means that the driver has a need for sudden acceleration when the power battery is low. At this time, in order to meet the driver's power demand and the power battery charging demand at the same time, the vehicle will automatically trigger a mode switching request from the series mode to the power split mode, and then the HCU will respond to the mode switching request, keep the clutch 102 in a closed state, the engine 101 in a driving state, and perform torque adjustment on the current motor torque of the first motor 103 to make the first synchronizer 105 meet the first gear switching condition.

[0094] In this embodiment, the HCU will respond to the vehicle mode switching request and send a clutch state maintaining request to the transmission controller, so that the transmission controller responds to the clutch state maintaining request and keeps the clutch 102 in the closed state; at the same time, it will send an engine state maintaining request to the engine controller, so that the engine controller responds to the engine state maintaining request and keeps the engine 101 in the driving state.

[0095] Furthermore, the HCU will also send a gear signal including the target gear corresponding to the power split mode to the transmission controller, so that the transmission controller obtains the target gear and switches from the current gear to the target gear when the second synchronizer 106 meets the second gear switching condition.

[0096] It should be noted that in series mode, the first synchronizer 105 is in the engaged gear. At this time, 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. When the vehicle switches from series mode to power split mode, the first synchronizer 105 needs to be disengaged from the engaged gear to the power split gear. At this time, the speed ratio between the first input end of the power split mechanism 104 and the transmission input shaft 107 can be set to a value greater than 1, such as 2:1, as needed. To avoid damage to the first synchronizer 105, the torque applied to the first synchronizer 105 during disengagement is required to be low, ideally zero.

[0097] In this embodiment, considering that when the clutch 102 is closed, the torques of the engine 101 and the first motor 103 can be applied to the power split mechanism 104 at the same time, therefore, by performing torque adjustment on the current motor torque of the first motor 103, the torque applied to the power split mechanism 104 by the first motor 103 can be used to offset the torque applied to the power split mechanism 104 by the engine 101, and then the torque of the power split mechanism 104 acting on the first synchronizer 105 can be adjusted. In this way, the crankshaft end torque can be balanced to the torque required for closing the first synchronizer 105 without opening the clutch 102 and without reducing the torque of the engine 101.

[0098] In a specific implementation, the HCU will respond to the mode switching request and send a torque adjustment request including the target motor torque to the motor controller, so that the motor controller is used to respond to the torque adjustment request and adjust the current motor torque of the first motor 103 according to the target motor torque, so that the first synchronizer 105 meets the first gear switching condition.

[0099] S202: When the first synchronizer 105 meets the first gear switching condition, the first synchronizer 105 is controlled to switch from the engagement gear to the power split gear; and the current motor speed of the first motor 103 is adjusted to make the second synchronizer 106 meet the second gear switching condition.

[0100] In this embodiment, after the HCU detects that the first synchronizer 105 meets the first gear switching condition and the current gear is the engaged gear, it will send a first gear switching instruction for indicating that the target gear is the power split gear to the transmission controller, so that the transmission controller responds to the gear switching instruction and controls the first synchronizer 105 to shift gears to the power split gear.

[0101] In this embodiment, if the HCU detects that the first synchronizer 105 has switched to the power diversion gear, it will trigger the speed adjustment of the first motor 103 and send a speed adjustment request including the target motor speed to the motor controller, so that the motor controller responds to the speed adjustment request and adjusts the current motor speed of the first motor 103 based on the target motor speed so that the second synchronizer 106 meets the second gear switching condition.

[0102] It should be noted that the second synchronizer 106 is disposed between the transmission input shaft 107 and the transmission output shaft 108 and is used to adjust the speed ratio between the transmission input shaft 107 and the transmission output shaft 108. When the second synchronizer 106 is engaged, the speed difference between the two ends of the second synchronizer 106 needs to be adjusted to a minimum value, ideally zero.

[0103] In this embodiment, considering that the first motor 103 is connected to the power splitting mechanism 104 and the first motor 103 has been used to achieve torque balance of the engine 101, therefore, by adjusting the speed of the first motor 103, it is also possible to adjust the speed of the transmission input shaft 107 without opening the clutch 102 and without reducing the torque of the engine 101, so that the second synchronizer 106 meets the second gear switching condition.

[0104] S203 : When the second synchronizer 106 satisfies the second gear switching condition, the second synchronizer 106 is controlled to switch from the neutral gear to the target gear, so that the vehicle switches from the series mode to the power split mode.

[0105] In this embodiment, after the HCU detects that the second synchronizer 106 meets the second gear shift condition and the current gear is neutral, it sends a second gear shift instruction including the target gear to the transmission controller. The transmission controller responds to the second gear shift instruction and controls the second synchronizer 106 to shift from neutral to the target gear corresponding to the power split mode. For a transmission with three forward gears, the target gear is typically 2nd or 3rd gear.

[0106] In this embodiment, after the HCU determines that the second synchronizer 106 has switched to the target gear, it will set the current driving mode of the vehicle from the series mode to the power split mode, and then control the output torque of the engine 101, the first motor 103 and the second motor according to the torque distribution strategy in the power split mode.

[0107] Specifically, the torque distribution strategy includes a front axle torque distribution strategy and a rear axle torque output strategy, wherein the HCU is used to execute the front axle torque distribution strategy, control the engine 101 to output a first torque with a positive value, and control the first motor 103 to output a second torque with a negative value, so as to charge the power battery while driving the front axle of the vehicle; at the same time, the HCU is also used to execute the rear axle torque output strategy, control the second motor to output a third torque with a positive value, so as to drive the rear axle of the vehicle.

[0108] It should be noted that the first torque is greater than the absolute value of the second torque. Thus, the first torque transmitted from the engine 101 to the power split mechanism 104 can be divided by the power split mechanism 104 into a power generation sub-torque and a driving sub-torque. The power generation sub-torque is equal to the absolute value of the second torque and is transmitted to the first motor 103 via the power split mechanism 104 to drive the first motor 103 to generate electricity, with the generated electricity being used to charge the power battery. The driving sub-torque is the difference between the absolute values ​​of the first and second torques and is transmitted via the power split mechanism 104 to the transmission input shaft 107. The transmission input shaft 107 is then transmitted to the front axle of the vehicle via the second synchronizer 106, the transmission output shaft 108, and the front axle differential 109, thereby driving the vehicle.

[0109] A vehicle mode switching method provided by an embodiment of the present disclosure sequentially adjusts the torque and speed of the first motor 103, so that during the vehicle mode switching process, the shifting operations of the first synchronizer 105 and the second synchronizer 106 can be completed sequentially without opening the clutch 102 and without interrupting the torque of the engine 101. In this way, the engine 101 can not only continuously drive the first motor 103 to remain in the power generation state through the power diversion mechanism 104 to meet the charging needs of the power battery, but can also immediately output torque to the wheel end through the power diversion mechanism 104, so that the vehicle can switch from the series mode to the power diversion mode more quickly and smoothly, effectively improving the power response performance of the vehicle during the mode switching process.

[0110] In a feasible embodiment, continuing to refer to Figure 1, the power diversion 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 a first input end of the power diversion mechanism 104, the sun gear 1042 is connected to the first motor 103 as a second input end of the power diversion mechanism 104, the ring gear 1041 is connected to the gearbox input shaft 107 as an output end of the power diversion mechanism 104, and the first synchronizer 105 is arranged between the planetary carrier 1044 and the ring gear 1041.

[0111] It should be noted that, in the series mode, the first synchronizer 105 is in the engaged gear. At this time, the planetary carrier 1044 and the ring gear 1041 are in a locked state. Since the second synchronizer 106 is in neutral, the driving force transmitted from the engine 101 to the planetary carrier 1044 through the clutch 102 will not be transmitted to the transmission output shaft 108 through the first synchronizer 105, the ring gear 1041 and the transmission input shaft 107, but will be transmitted to the first motor 103 in sequence through multiple planetary gears 1043 and the sun gear 1042 to drive the first motor 103 to generate electricity, and the generated electricity is provided to the second motor to drive the vehicle.

[0112] 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, so as 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 transmission input shaft 107, the second synchronizer 106, the transmission output shaft 108 and the front axle differential 109 in sequence, so as to drive the vehicle. Based on the above structure, S201 can specifically include the following sub-steps:

[0113] S201 - 1 : Determine a target motor torque of the first motor 103 based on the current engine torque of the engine 101 and the first speed ratio between the sun gear 1042 and the planet carrier 1044 .

[0114] It should be noted that since the first motor 103 is connected to the engine 101 in sequence through the sun gear 1042, multiple planetary gears 1043 and the planetary carrier 1044, and there is a gear ratio between the planetary carrier 1044 and the sun gear 1042, the first motor 103 cannot be directly controlled to output a torque opposite to the current engine torque of the engine 101.

[0115] In this embodiment, to effectively balance the torques applied to the planetary gear 1043 by the engine 101 and the first motor 103, the HCU determines the target motor torque of the first motor 103 based on the current engine torque of the engine 101 and the first speed ratio between the sun gear 1042 and the planetary carrier 1044. Specifically, the target motor torque can be determined according to the following formula: T2 = -T1×i1 (1);

[0116] Wherein, T2 represents the target motor torque of the first motor 103 , T1 represents the current engine torque of the engine 101 , and i1 represents the first speed ratio between the sun gear 1042 and the planet carrier 1044 .

[0117] S201 - 2 : Based on the target motor torque, perform torque adjustment on the current motor torque of the first motor 103 .

[0118] In this embodiment, after determining the target motor torque, the HCU activates the torque control mode of the motor controller, so that the motor controller adjusts the current motor torque of the first motor 103 to the target motor torque.

[0119] In a specific implementation, the current motor torque of the first motor 103 can be controlled to gradually increase or decrease to the target motor torque according to a preset torque adjustment gradient. The torque adjustment gradient represents the change in the current motor torque of the first motor 103 per unit time, and can be set to, for example, 100 N·m / s.

[0120] In this embodiment, by gradually increasing or decreasing 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 affect the driving stability of the vehicle.

[0121] In a feasible implementation manner, the vehicle mode switching method may further include the following steps:

[0122] S301: When the first torque difference between the current motor torque and the target motor torque is less than the first torque threshold, trigger the timing of the first duration of the first torque difference being less than the first torque threshold and the second duration of the fluctuation amplitude of the current engine torque being less than the second torque threshold.

[0123] In this embodiment, considering that torque fluctuations may occur in both the first motor 103 and the engine 101 during the torque adjustment process, in order to ensure the smooth implementation of the shifting operation of the first synchronizer 105, the torque fluctuations of the first motor 103 and the engine 101 will be detected to determine whether the first motor 103 and the engine 101 are in a stable operation state at the same time.

[0124] In a specific implementation, when the HCU first detects that the first torque difference between the current motor torque and the target motor torque is less than the first torque threshold, it will simultaneously trigger the timing of the first duration and the second duration. The first duration represents the duration of continuous and stable operation of the first motor 103 in the torque dimension; the second duration represents the duration of continuous and stable operation of the engine 101 in the torque dimension.

[0125] It should be noted that, considering that the control accuracy of the first motor 103 is greater than that of the engine 101, the second torque threshold can be set to be greater than the first torque threshold. For example, the first torque threshold can be set to 3N·m and the second torque threshold can be set to 5N·m.

[0126] S302 : When the first duration is greater than a first duration threshold, and the second duration is greater than a second duration threshold, determine that the first synchronizer 105 meets a first gear shifting condition.

[0127] In this embodiment, when the first duration is greater than the first duration threshold, it means that the current motor torque of the first motor 103 fluctuates around the target motor torque with a fluctuation amplitude less than the first torque threshold, that is, it is in a stable operating state; when the second duration is greater than the second duration threshold, it means that the current engine torque of the engine 101 fluctuates around the original engine 101 torque with a fluctuation amplitude less than the second torque threshold, and is also in a stable operating state. Among them, the first duration threshold and the second duration threshold can be set specifically according to the control accuracy of the first motor 103 and the engine 101, for example, both can be set to 50ms. It should be noted that the original engine 101 torque represents the current engine torque of the engine 101 used when calculating the target motor torque of the first motor 103.

[0128] In this embodiment, by monitoring the current motor torque and the current engine torque simultaneously during the process of torque adjustment of the first motor 103, it is possible to accurately determine whether the first synchronizer 105 meets the first gear switching condition, thereby ensuring that the first synchronizer 105 can shift gears smoothly, and effectively avoiding damage to the first synchronizer 105 and gear shift failure.

[0129] In a feasible implementation, S202 may specifically include the following sub-steps:

[0130] S202 - 1 : Determine a target motor speed of the first motor 103 based on the current gear position of the first synchronizer 105 and the target gear position of the second synchronizer 106 .

[0131] In this embodiment, since a first synchronizer 105 and a second synchronizer 106 are provided between the first motor 103 and the transmission input shaft 107, and different gear states of the first synchronizer 105 and the second synchronizer 106 correspond to different speed ratios, in order to accurately calculate the target motor speed of the first motor 103 and ensure that the second synchronizer 106 can be smoothly engaged in the target gear, the HCU will determine the target motor speed of the first motor 103 based on the current gear of the first synchronizer 105 and the target gear of the second synchronizer 106.

[0132] In a specific implementation, S202-1 may specifically include the following sub-steps:

[0133] S202-1-1: When the current gear position of the first synchronizer 105 is the power split gear, determine that the speed ratio between the planet carrier 1044 and the ring gear 1041 is the second speed ratio.

[0134] It should be noted that different gears of the first synchronizer 105 correspond to different speed ratios. Specifically, when the first synchronizer 105 is in the power split gear, the first synchronizer 105 is in a disengaged state. At this time, there is a second speed ratio greater than 1 between the planetary carrier 1044 and the ring gear 1041, so that the engine 101 can drive the vehicle faster; and when the first synchronizer 105 is in the engagement gear, the first synchronizer 105 is in a locked state. At this time, the speed ratio between the planetary carrier 1044 and the ring gear 1041 is 1:1, and the engine 101 will no longer transmit power to the transmission input shaft 107 through the ring gear 1041 to drive the vehicle.

[0135] S202-1-2: Based on the target gear position of the second synchronizer 106, determine that the speed ratio between the transmission input shaft 107 and the target wheel is the third speed ratio.

[0136] In this embodiment, different gear positions of the second synchronizer 106 correspond to different speed ratios. Continuing with FIG1 , the forward gears include three gear positions, D1, D2, and D3, with successively decreasing speed ratios, each of which has its own corresponding speed ratio. During mode switching, the HCU determines the target gear position of the second synchronizer 106 based on the current vehicle speed and the driver's power demand, and further determines the speed ratio corresponding to the target gear position. This speed ratio represents the speed ratio between the transmission input shaft 107 and the transmission output shaft 108. Therefore, combining the speed ratio corresponding to the target gear position and the speed ratio between the transmission output shaft 108 and the target wheel, the speed ratio between the transmission input shaft 107 and the target wheel can be calculated as the third speed ratio.

[0137] It should be noted that the target wheel represents the wheel located on the same side as the first motor 103. For example, when the first motor 103, the engine 101, and the gearbox are located on the front axle of the vehicle, the target wheel represents the front axle wheel. The current wheel speed can be determined based on a speed signal collected by a wheel speed sensor or 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.

[0138] S202-1-3: Determine a fourth speed ratio between the target wheel and the first motor 103 based on the second speed ratio, the first speed ratio, and the third speed ratio.

[0139] In this embodiment, based on the second speed ratio and the first speed ratio, the speed ratio between the sun gear 1042 and the ring gear 1041 can be calculated. Since the first motor 103 and the sun gear 1042 have the same speed, and the ring gear 1041 and the transmission input shaft 107 have the same speed, the fourth speed ratio between the target wheel and the first motor 103 can be calculated by further combining the third speed ratio.

[0140] In a specific implementation, the fourth speed ratio between the target wheel and the first motor 103 can be calculated according to the following formula: i4 = i1 × i2 × i3 (2);

[0141] Among them, i4 represents the fourth speed ratio between the target wheel and the first motor 103, i1 represents the first speed ratio between the sun gear 1042 and the planetary carrier 1044, i2 represents the second speed ratio between the planetary carrier 1044 and the ring gear 1041, and i3 represents the speed ratio between the gearbox input shaft 107 and the target wheel.

[0142] S202-1-4: Determine the target motor speed of the first motor 103 based on the fourth speed ratio and the current wheel speed of the target wheel.

[0143] In a specific implementation, the target motor speed of the first motor 103 can be calculated according to the following formula: n=n0×i4 (3);

[0144] Wherein, n represents the target motor speed of the first motor 103 , n0 represents the current wheel speed of the target wheel, and i4 represents the fourth speed ratio between the target wheel and the first motor 103 .

[0145] S202 - 2 : Based on the target motor speed, the current motor speed of the first motor 103 is adjusted.

[0146] In this embodiment, when the HCU sends a speed control request to the motor controller, it also sends 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 to achieve precise control of the motor speed.

[0147] 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.

[0148] 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.

[0149] In this embodiment, by comprehensively considering the current gear of the first synchronizer 105 and the target gear of 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 at both ends of the second synchronizer 106, ensuring that the second synchronizer 106 can be smoothly engaged in the target gear.

[0150] It should be noted that after the vehicle completes the switching process from series mode to power split mode, the HCU will control the first motor 103 to exit the speed control mode and activate the torque control mode so that the first motor 103 can stably output torque and achieve the purpose of stable power generation.

[0151] In a feasible implementation manner, the vehicle mode switching method may further include the following steps:

[0152] S401 : When the current motor speed of the first motor 103 reaches the target motor speed, timing is triggered for a third duration during which the fluctuation amplitude of the current motor speed is less than a speed threshold.

[0153] In this embodiment, considering that the speed of the first motor 103 may fluctuate during the speed adjustment process, in order to ensure the smooth implementation of the gear shifting operation of the second synchronizer 106, the speed fluctuation of the first motor 103 will be detected based on the preset speed threshold to determine whether the current motor speed of the first motor 103 is in a stable state.

[0154] It should be noted that the shifting requirements of the second synchronizer 106 vary at different vehicle speeds. Higher vehicle speeds result in more dramatic speed changes. Therefore, a corresponding speed threshold can be determined based on the vehicle's current speed. The speed threshold can decrease as the current speed increases. For example, when the current vehicle speed is less than or equal to 2 km / h, the speed threshold can be set to 50 rpm. When the current vehicle speed is greater than 2 km / h, the speed threshold can be set to 20 rpm. By matching a lower speed threshold at higher speeds, the second synchronizer 106 can further ensure smooth shifting while the vehicle is in motion.

[0155] In a specific implementation, after the HCU detects for the first time that the current motor speed reaches the target motor speed, it will trigger the timing of the third duration, wherein the third duration represents the duration of continuous and stable operation of the first motor 103 in terms of speed.

[0156] S402 : When the third duration is greater than the third duration threshold, determine that the second synchronizer 106 meets the second gear shifting condition.

[0157] In this embodiment, when the third duration is greater than the third duration threshold, it indicates that the current motor speed of the first motor 103 fluctuates around the target motor speed with a fluctuation amplitude less than the speed threshold, that is, it is in a stable operating state.

[0158] In this embodiment, by monitoring the current motor speed during the speed adjustment of the first motor 103, it is possible to accurately determine whether the second synchronizer 106 meets the second gear switching conditions, thereby ensuring that the second synchronizer 106 can shift gears smoothly, effectively avoiding damage to the second synchronizer 106 and gear shift failure.

[0159] In a feasible implementation, S203 may specifically include the following sub-steps:

[0160] S203 - 1 : When the second synchronizer 106 satisfies the second gear shifting condition, the second synchronizer 106 is controlled to perform a pre-synchronization operation, so that the shift fork of the second synchronizer 106 moves to the pre-synchronization position.

[0161] It should be noted that the shift fork is a key component in the transmission's shift mechanism, used to shift the synchronizer ring gear, changing the synchronizer's input / output speed ratio to achieve gear shifting. When the second synchronizer 106 is in neutral, the shift fork is in its home position, i.e., its starting position. Gear shifting of the second synchronizer 106 can be achieved by moving it left or right.

[0162] In this embodiment, the pre-synchronization position refers to a position between the starting position of the shift fork and the target position. Preferably, the pre-synchronization position can be set at a position close to the target position to shorten the shifting time.

[0163] In a specific implementation, after determining that the second synchronizer 106 meets the second gear shifting condition, the HCU will send a synchronizer pre-synchronization request to the transmission controller, so that the transmission controller responds to the synchronizer pre-synchronization request and controls the synchronizer fork to move to the pre-synchronization position.

[0164] S203-2: When it is determined that the shift fork of the second synchronizer 106 reaches the pre-synchronization position and the first torque difference between the current motor torque and the target motor torque is less than the fourth torque threshold, control the second synchronizer 106 to move from the pre-synchronization position to the target position so that the second synchronizer 106 switches to the target gear.

[0165] In this embodiment, after detecting that the shift fork of the second synchronizer has reached the pre-synchronization position, the HCU monitors the current motor torque to determine whether the current motor torque remains stable. This ensures that the current motor torque remains stable before executing the shift operation, ensuring safe shifting of the second synchronizer 106.

[0166] In a second aspect, referring to FIG3 , an embodiment of the present disclosure provides a vehicle mode switching device 300 , which is applied to a vehicle. 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:

[0167] a torque adjustment module 301 for responding to a mode switch request from the series mode to the power split mode, keeping the clutch 102 in a closed state, the engine 101 in a driving state, and adjusting the current motor torque of the first motor 103 so that the first synchronizer 105 meets a first gear shift condition;

[0168] The speed regulating module 302 is configured to control the first synchronizer 105 to switch from the engagement gear to the power split gear when the first synchronizer 105 satisfies the first gear shifting condition; and to regulate the current motor speed of the first motor 103 so that the second synchronizer 106 satisfies the second gear shifting condition;

[0169] The gear switching module 303 is configured to control the second synchronizer 106 to switch from neutral to a target gear when the second synchronizer 106 satisfies a second gear switching condition, so as to switch the vehicle from the series mode to the power split mode.

[0170] In one embodiment of the present disclosure, 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, the sun gear 1042 is connected to the first motor 103, the ring gear 1041 is connected to the transmission input shaft 107, and the first synchronizer 105 is disposed between the planetary carrier 1044 and the ring gear 1041. The torque adjustment module 301 includes:

[0171] a target motor torque determination submodule, configured to determine a target motor torque of the first motor 103 based on a current engine torque of the engine 101 and a first speed ratio between the sun gear 1042 and the planet carrier 1044 ;

[0172] The torque adjustment submodule is configured to adjust the current motor torque of the first motor 103 based on the target motor torque.

[0173] In one embodiment of the present disclosure, the vehicle mode switching device 300 further includes:

[0174] a first timing module for triggering, when a first torque difference between the current motor torque and the target motor torque is less than a first torque threshold, timing a first duration for which the first torque difference is less than the first torque threshold and timing a second duration for which the fluctuation amplitude of the current engine torque is less than a second torque threshold;

[0175] The first condition determination module is configured to determine that the first synchronizer 105 satisfies a first gear shift condition when the first duration is greater than a first duration threshold and the second duration is greater than a second duration threshold.

[0176] In one embodiment of the present disclosure, the speed adjustment module 302 includes:

[0177] a target motor speed determination submodule, configured to determine a target motor speed of the first motor 103 based on the current gear position of the first synchronizer 105 and the target gear position of the second synchronizer 106 ;

[0178] The speed adjustment submodule is configured to adjust the current motor speed of the first motor 103 based on the target motor speed.

[0179] In one embodiment of the present disclosure, the target motor speed determination submodule includes:

[0180] a first speed ratio determining unit, configured to determine, when the current gear position of the first synchronizer 105 is the power split gear, that the speed ratio between the planet carrier 1044 and the ring gear 1041 is the second speed ratio;

[0181] a second speed ratio determining unit, configured to determine, based on the target gear position of the second synchronizer 106 , a speed ratio between the transmission input shaft 107 and the target wheel as a third speed ratio;

[0182] a third speed ratio determining unit, configured to determine a fourth speed ratio between the target wheel and the first motor 103 based on the second speed ratio, the first speed ratio, and the third speed ratio;

[0183] The target motor speed determining unit is configured to determine a target motor speed of the first motor 103 based on the fourth speed ratio and the current wheel speed of the target wheel.

[0184] In one embodiment of the present disclosure, the vehicle mode switching device 300 further includes:

[0185] A second timing module is configured to trigger timing of a third duration during which the fluctuation amplitude of the current motor speed is less than a speed threshold when the current motor speed of the first motor 103 reaches a target motor speed;

[0186] The second condition determination module is configured to determine that the second synchronizer 106 satisfies a second gear shift condition when the third duration is greater than a third duration threshold.

[0187] In one embodiment of the present disclosure, the gear switching module 303 includes:

[0188] a pre-synchronization submodule, configured to control the second synchronizer 106 to perform a pre-synchronization operation when the second synchronizer 106 satisfies a second gear shifting condition, so as to move the shift fork of the second synchronizer 106 to a pre-synchronization position;

[0189] The gear shift submodule is used to control the second synchronizer 106 to move from the pre-synchronization position to the target position when it is determined that the shift fork of the second synchronizer 106 reaches the pre-synchronization position and the first torque difference between the current motor torque and the target motor torque is less than the fourth torque threshold, so that the second synchronizer 106 switches to the target gear.

[0190] It should be noted that the specific implementation of the vehicle mode switching device 300 in the embodiment of the present disclosure refers to the specific implementation of the vehicle mode switching method proposed in the first aspect of the embodiment of the present disclosure, and will not be repeated here.

[0191] In the third aspect, referring to Figure 4, an embodiment of the present disclosure provides a vehicle mode switching system 400, which is used in a vehicle, and 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 vehicle mode switching system 400 includes a vehicle controller 401, a gearbox controller 402, a motor controller 403 and an engine controller 404.

[0192] The vehicle controller is configured to, in response to a mode switching request from the series mode to the power split mode, send a clutch state maintaining request to the transmission controller, send an engine state maintaining request to the engine controller, and send a torque adjustment request to the motor controller;

[0193] The transmission controller is configured to keep the clutch 102 in a closed state in response to the clutch state keeping request;

[0194] The engine controller is configured to maintain the engine 101 in a driving state in response to the engine state maintaining request;

[0195] The motor controller is configured to perform torque adjustment on the current motor torque of the first motor 103 in response to the torque adjustment request, so that the first synchronizer 105 meets the first gear shift condition;

[0196] The vehicle controller is further configured to control the transmission controller to switch the first synchronizer 105 from the engagement gear to the power split gear when the first synchronizer 105 meets the first gear switching condition, and send a speed adjustment request to the motor controller;

[0197] The motor controller is further configured to adjust the current motor speed of the first motor 103 in response to the speed adjustment request, so that the second synchronizer 106 meets the second gear shift condition;

[0198] The vehicle controller is also used to control the transmission controller to switch the second synchronizer 106 from neutral to the target gear when the second synchronizer 106 meets the second gear switching condition, so as to switch the vehicle from the series mode to the power split mode.

[0199] It should be noted that the specific implementation of the vehicle mode switching system 400 of the embodiment of the present disclosure refers to the specific implementation of the vehicle mode switching method proposed in the first aspect of the present disclosure, and will not be repeated here.

[0200] In a fourth aspect, referring to FIG. 5 , an embodiment of the present disclosure provides a vehicle 500 , including the vehicle mode switching system 400 proposed in the third aspect of the present disclosure.

[0201] It should be noted that the specific implementation of the vehicle 500 in the embodiment of the present disclosure refers to the specific implementation of the vehicle mode switching system 400 proposed in the third aspect of the embodiment of the present disclosure, and will not be repeated here.

[0202] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, i.e., they may be located in one location or distributed across multiple network units. Some or all of the modules may be selected based on actual needs to achieve the objectives of the present embodiment. Persons of ordinary skill in the art will be able to understand and implement the present invention without inventive effort.

[0203] The various component embodiments of the present disclosure can be implemented in hardware, or in software modules running on one or more processors, or in a combination thereof. Those skilled in the art will appreciate 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 the embodiments of the present disclosure. The present disclosure can also be implemented as a device or apparatus program for executing part or all of the methods described herein, for example, a computer program and a computer program product. Such a program implementing the present disclosure 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.

[0204] For example, FIG6 shows a computing and processing device that can implement the method according to the present disclosure. The computing and processing device traditionally includes a processor 1010 and a computer program product or computer-readable medium in the form of a memory 1020. The memory 1020 can be an electronic memory such as a flash memory, an EEPROM (Electrically Erasable Programmable Read-Only Memory), an EPROM, a hard disk, or a ROM. The memory 1020 has a storage space 1030 for program codes for executing any method steps in the above method. For example, the storage space 1030 for program codes can include individual program codes for implementing the above method steps S201-S203, S01-S302, and S401-S402 respectively. These program codes can be read from or written into one or more computer program products. These computer program products include program code carriers such as a hard disk, a compact disc (CD), a memory card, or a floppy disk. Such a computer program product is typically a portable or fixed storage unit as described with reference to FIG7. The storage unit may have storage segments, storage spaces, etc. arranged similarly to the memory 1020 in the computing and processing device of FIG6 . The program code may be compressed, for example, in an appropriate form. Typically, the storage unit includes computer-readable code 1031, i.e., code that can be read by a processor such as 1010 , which, when executed by the computing and processing device, causes the computing and processing device to perform the steps of the method described above.

[0205] References herein to "one embodiment," "an embodiment," or "one or more embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present disclosure. Furthermore, please note that instances of the phrase "in one embodiment" do not necessarily all refer to the same embodiment.

[0206] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present disclosure, rather than to limit them. Although the present disclosure has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present disclosure.

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: In response to a mode switching request for switching from a series mode to a power split mode, keep the clutch in a closed state, keep the engine in a driving state, and perform torque adjustment on the current motor torque of the first motor so that the first synchronizer meets the first gear shifting condition; When the first synchronizer meets the first gear shifting condition, control the first synchronizer to switch from an engaged gear to a power split gear; and perform speed adjustment on the current motor speed of the first motor so that the second synchronizer meets the second gear shifting condition; When the second synchronizer meets the second gear shifting condition, control the second synchronizer to switch from a neutral gear to a target gear so that the vehicle switches from the series mode to the power split mode.

2. The vehicle mode switching method according to claim 1, wherein The power split mechanism includes a ring gear, a sun gear, a plurality of planet gears meshing between the ring gear and the sun gear, and a planet carrier rotatably connected to the plurality of planet gears; the planet carrier is connected to the engine as the first input end, the sun gear is connected to the first motor as the second input end, the ring gear is connected to the transmission input shaft as the output end, and the first synchronizer is disposed between the planet carrier and the ring gear; The step of performing torque adjustment on the current motor torque of the first motor includes: Based on the current engine torque of the engine and a first gear ratio between the sun gear and the planet carrier, determine the target motor torque of the first motor; Based on the target motor torque, perform torque adjustment on the current motor torque of the first motor.

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

4. The vehicle mode switching method according to claim 2, wherein The step of performing speed adjustment on the current motor speed of the first motor includes: Based on the current gear of the first synchronizer and the target gear of the second synchronizer, determine the target motor speed of the first motor; Based on the target motor speed, perform speed adjustment on the current motor speed of the first motor.

5. The vehicle mode switching method according to claim 4, wherein, The step of determining the target motor speed of the first motor based on the current gear position of the first synchronizer and the target gear position of the second synchronizer includes: When the current gear position of the first synchronizer is the power split gear position, determining that the speed ratio between the planet carrier and the ring gear is the second speed ratio; Based on the target gear position of the second synchronizer, determining that the speed ratio between the transmission input shaft and the target wheel is the third speed ratio; Based on the second speed ratio, the first speed ratio, and the third speed ratio, determining the fourth speed ratio between the target wheel and the first motor; Based on the fourth speed ratio and the current wheel speed of the target wheel, determining the target motor speed of the first motor.

6. The vehicle mode switching method according to claim 4, wherein The method further includes: When the current motor speed of the first motor reaches the target motor speed, triggering the timing of the third duration during which the fluctuation amplitude of the current motor speed is less than the speed threshold; When the third duration is greater than the third duration threshold, determining that the second synchronizer meets the second gear shift condition.

7. The vehicle mode switching method according to claim 2, wherein The step of controlling the second synchronizer to shift from the neutral gear to the target gear position when the second synchronizer meets the second gear shift condition includes: When the second synchronizer meets the second gear shift condition, controlling the second synchronizer to perform a pre-synchronization operation to move the shift fork of the second synchronizer to the pre-synchronization position; When it is determined that the shift fork of the second synchronizer reaches the pre-synchronization position and the first torque difference between the current motor torque and the target motor torque is less than the fourth torque threshold, controlling the second synchronizer to move from the pre-synchronization position to the target position so that the second synchronizer shifts to the target gear position.

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, in response to a mode switching request for switching from the series mode to the power split mode, keep the clutch in a closed state, keep the engine in a driving state, and perform torque adjustment on the current motor torque of the first motor so that the first synchronizer meets the first gear shift condition; A speed adjustment module, configured to, when the first synchronizer meets the first gear shift condition, control the first synchronizer to shift from the engaged gear to the power split gear; and perform speed adjustment on the current motor speed of the first motor so that the second synchronizer meets the second gear shift condition; The gear shifting module is configured to control the second synchronizer to shift from neutral to the target gear when the second synchronizer meets the second gear shifting condition, so that the vehicle switches from the series mode to the power split 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 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 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. Among them, The vehicle controller is configured to, in response to a mode switching request from the series mode to the power split mode, send a clutch state holding request to the transmission controller, send an engine state holding request to the engine controller, and send a torque adjustment 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 engine controller is configured to, in response to the engine state holding request, keep the engine in a driving state. The motor controller is configured to, in response to the torque adjustment request, adjust the current motor torque of the first motor to make the first synchronizer meet the first gear shifting condition. The vehicle controller is further configured to, when the first synchronizer meets the first gear shifting condition, control the transmission controller to shift the first synchronizer from the engaged gear to the power split gear, and send a speed adjustment request to the motor controller. The motor controller is further configured to, in response to the speed adjustment request, adjust the current motor speed of the first motor to make the second synchronizer meet the second gear shifting condition. The vehicle controller is further configured to, when the second synchronizer meets the second gear shifting condition, control the transmission controller to shift the second synchronizer from neutral to the target gear, so that the vehicle switches from the series mode to the power split mode.

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

11. A computer program includes computer-readable code that, 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 stores the computer program according to claim 11.

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