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

Abstract

A vehicle mode switching method, apparatus, and system, a vehicle, a computer program, and a readable medium, relating to the technical field of vehicle control. When a vehicle meets a mode switching condition of switching from a power split mode to a direct drive mode, a clutch (102) is kept in an engaged state, and torque adjustment is performed on an engine (101) and a first motor (103), so that when a first synchronizer (105) meets a torque condition, rotation speed adjustment can be performed on the first motor (103), and when the first synchronizer (105) meets a rotation speed condition, the first synchronizer (105) can be controlled to switch from a power split gear to a combined gear, so as to switch the vehicle from the power split mode to the direct drive mode. A gear shifting operation of the first synchronizer (105) is smoothly completed without disengaging or engaging the clutch (102), so that the engine (101) can quickly output torque while the duration of mode switching is shortened, thereby improving the power response performance of the 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 202311864289.7 and titled “A Vehicle Mode Switching Method, 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 direct-drive mode, it is typically necessary to first open the clutch, then reduce engine torque and regulate engine 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 results in a long mode switch time and untimely engine power response, which in turn affects the vehicle's dynamic 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 transmission; the transmission includes a power split mechanism, a first synchronizer, and a transmission input shaft; the engine is connected to a first input end of the power split mechanism via the clutch, the first motor is connected to a second input end of the power split mechanism, an output end of the power split mechanism is connected to the transmission input shaft, and the first synchronizer is disposed between the first input end and the output end; the method comprises:

[0007] When the vehicle satisfies a mode switching condition for switching from a power split mode to a direct drive mode, the clutch is kept in a closed state, and torque adjustment is performed on the engine and the first motor so that the first synchronizer satisfies a torque condition;

[0008] When the first synchronizer satisfies the torque condition, adjusting the speed of the first motor so that the first synchronizer satisfies the speed condition;

[0009] When the first synchronizer meets the speed 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 direct drive mode.

[0010] In some embodiments of the present application, the method further comprises:

[0011] When the vehicle is in the power split mode, obtaining the current remaining power of the power battery and determining whether the driver has a strong power demand;

[0012] When it is determined that the driver has the strong power demand and the current remaining power is greater than the power threshold, it is determined that the vehicle meets the mode switching condition for switching from the power split mode to the direct drive mode.

[0013] In some embodiments of the present application, the step of determining whether the driver has a strong power demand includes:

[0014] Get the current throttle opening and current throttle opening change rate of the accelerator pedal;

[0015] When the current throttle opening is greater than an opening threshold and the current throttle opening change rate is greater than a change rate threshold, it is determined that the driver has a strong power demand.

[0016] In some embodiments of the present application, the step of adjusting the torque of the engine and the first motor includes:

[0017] Based on a preset torque adjustment gradient, the current engine torque of the engine and the current motor torque of the first motor are controlled to follow a preset first target torque.

[0018] In some embodiments of the present application, the vehicle further includes a second motor, and the method further includes:

[0019] determining a compensation torque for the second electric machine based on the current engine torque and the current electric machine torque;

[0020] determining a target driving torque of the second motor based on the compensation torque and a current driving torque of the second motor;

[0021] During the process of torque adjustment of the engine and the first motor, the second motor is controlled to gradually increase the current driving torque to the target driving torque based on the torque adjustment gradient.

[0022] In some embodiments of the present application, the method further comprises:

[0023] When a first torque difference between the current engine torque and the first target 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;

[0024] When a second torque difference between the current motor torque and the first target torque is less than a second torque threshold, triggering timing of a second duration for which the second torque difference is less than the second torque threshold;

[0025] 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 torque condition.

[0026] 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;

[0027] The step of adjusting the speed of the first motor includes:

[0028] 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 first speed ratio;

[0029] determining a target ring gear speed of the ring gear based on a current engine speed of the engine and the first speed ratio;

[0030] determining a target motor speed of the first motor based on the target ring gear speed and a second speed ratio between the ring gear and the sun gear;

[0031] The current motor speed of the first motor is controlled to follow the target motor speed.

[0032] In some embodiments of the present application, the method further comprises:

[0033] determining a current ring gear speed of the ring gear based on the current motor speed and the second speed ratio;

[0034] determining a current planet carrier speed of the planet carrier based on the current engine torque;

[0035] 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 speed condition.

[0036] In some embodiments of the present application, when the first synchronizer meets the speed condition, the step of controlling the first synchronizer to switch from the power split gear to the engagement gear includes:

[0037] When the first synchronizer satisfies the speed condition, the sum of the first target torque and a preset shift assist torque is determined as the second target torque;

[0038] The current motor torque of the first motor is controlled to follow the second target torque to assist the first synchronizer in shifting from the power split gear to the engagement gear.

[0039] 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 first synchronizer, and a gearbox input shaft; the engine is connected to a first input end of the power split mechanism via the clutch, the first motor is connected to a second input end of the power split mechanism, an output end of the power split mechanism is connected to the gearbox input shaft, and the first synchronizer is disposed between the first input end and the output end; the device comprises:

[0040] a torque adjustment module, configured to, when the vehicle satisfies a mode switching condition for switching from a power split mode to a direct drive mode, keep the clutch in a closed state and perform torque adjustment on the engine and the first motor so that the first synchronizer satisfies a torque condition;

[0041] a speed regulating module, configured to regulate the speed of the first motor when the first synchronizer satisfies the torque condition, so that the first synchronizer satisfies the speed condition;

[0042] The gear switching module is used to control the first synchronizer to switch from the power split gear to the engagement gear when the first synchronizer meets the speed condition, so as to switch the vehicle from the power split mode to the direct drive mode.

[0043] In some embodiments of the present application, the vehicle mode switching device further includes:

[0044] an information acquisition submodule, configured to obtain the current remaining power of the power battery and determine whether the driver has a strong power demand when the vehicle is in the power split mode;

[0045] The condition determination submodule is used to determine that the vehicle meets the mode switching condition for switching from the power split mode to the direct drive mode when it is determined that the driver has the strong power demand and the current remaining power is greater than the power threshold.

[0046] In some embodiments of the present application, the information acquisition submodule includes:

[0047] A pedal information acquisition unit, configured to acquire a current throttle opening and a current throttle opening change rate of the throttle pedal;

[0048] The power demand determination unit is configured to determine that the driver has a strong power demand when the current throttle opening is greater than an opening threshold and a current throttle opening change rate is greater than a change rate threshold.

[0049] In some embodiments of the present application, the torque adjustment module includes:

[0050] The torque regulation submodule is configured to control the current engine torque of the engine and the current motor torque of the first motor to follow a preset first target torque based on a preset torque regulation gradient.

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

[0052] a compensation torque determination module, configured to determine a compensation torque of the second motor based on the current engine torque and the current motor torque;

[0053] 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;

[0054] 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 and the first motor.

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

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

[0057] a second timing module, configured to trigger timing of a second duration of time during which the second torque difference is less than the second torque threshold when a second torque difference between the current motor torque and the first target torque is less than a second torque threshold;

[0058] The first condition determination module is configured to determine that the second 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.

[0059] 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; the speed regulation module includes:

[0060] 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 planet carrier and the ring gear is a first speed ratio;

[0061] a target ring gear speed determining submodule, configured to determine a target ring gear speed of the ring gear based on a current engine speed of the engine and the first gear ratio;

[0062] a motor speed determination submodule, configured to determine a target motor speed of the first motor based on the target ring gear speed and a second speed ratio between the ring gear and the sun gear;

[0063] The motor speed control submodule is used to control the current motor speed of the first motor to follow the target motor speed.

[0064] In some embodiments of the present application, the vehicle mode switching device further includes:

[0065] a current ring gear speed determining module, configured to determine a current ring gear speed of the ring gear based on the current motor speed and the second speed ratio;

[0066] a current planet carrier speed determining module, configured to determine a current planet carrier speed of the planet carrier based on the current engine torque;

[0067] The second condition determination module is configured to determine that the first synchronizer satisfies the speed condition when a speed difference between the current ring gear speed and the current planet carrier speed is less than a speed difference threshold.

[0068] In some embodiments of the present application, the gear switching module includes:

[0069] a target torque determination submodule, configured to determine, when the first synchronizer satisfies the speed condition, a sum of the first target torque and a preset shift assist torque as a second target torque;

[0070] The gear shift submodule is configured to control the current motor torque of the first motor to follow the second target torque, so as to assist the first synchronizer in shifting from the power split gear to the engagement gear.

[0071] In a third aspect, 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 first synchronizer, and a gearbox input shaft; 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, 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,

[0072] The vehicle controller is configured to send a clutch state maintaining request to the transmission controller, an engine torque adjustment request to the engine controller, and a motor torque adjustment request to the motor controller when the vehicle satisfies a mode switching condition for switching from a power split mode to a direct drive mode;

[0073] The transmission controller is configured to maintain the clutch in a closed state in response to the clutch state maintaining request;

[0074] The engine controller is configured to adjust the torque of the engine in response to the engine torque adjustment request, and the motor controller is configured to adjust the torque of the first motor in response to the motor torque adjustment request, so that the first synchronizer meets a torque condition;

[0075] The vehicle controller is further configured to send a speed adjustment request to the motor controller when the first synchronizer satisfies the torque condition;

[0076] The motor controller is further configured to adjust the speed of the first motor in response to the speed adjustment request so that the first synchronizer meets a speed condition;

[0077] The vehicle controller is further configured to send a gear shift request to the transmission controller when the first synchronizer meets the speed condition;

[0078] The transmission controller is further configured to control the first synchronizer to switch from a power split gear to an engagement gear in response to the gear switching request, so as to switch the vehicle from the power split mode to the direct drive mode.

[0079] 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.

[0080] 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.

[0081] 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.

[0082] Compared with the prior art, this application has the following advantages:

[0083] A vehicle mode switching method provided in an embodiment of the present application is capable of maintaining a clutch in a closed state and performing torque adjustment on the engine and the first motor when the vehicle satisfies the mode switching conditions for switching from a power split mode to a direct drive mode, so that when the first synchronizer satisfies the torque conditions, the speed of the first motor can be adjusted. Furthermore, when the first synchronizer satisfies the speed conditions, the first synchronizer can be controlled to switch from a power split gear to an engagement gear, so that the vehicle switches from the power split mode to the direct drive mode. By first performing torque adjustment on the engine and the first motor and then adjusting the speed of the first motor, the embodiment of the present application enables the first synchronizer's shifting operation to be successfully completed without opening or closing the clutch during the vehicle mode switching process. In this way, the vehicle can switch from the power split mode to the direct drive mode more quickly and smoothly, effectively shortening the mode switching time while enabling the engine to quickly output torque, thereby improving the vehicle's dynamic response performance during the mode switching process.

[0084] 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

[0085] 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.

[0086] FIG1 is a schematic structural diagram of a hybrid vehicle in an embodiment of the present application.

[0087] FIG2 is a flowchart of the steps of a vehicle mode switching method in an embodiment of the present application.

[0088] FIG3 is a schematic diagram of functional modules of a vehicle mode switching device in an embodiment of the present application.

[0089] FIG4 is a schematic structural diagram of a vehicle mode switching system in an embodiment of the present application.

[0090] FIG5 is a schematic structural diagram of a vehicle in an embodiment of the present application.

[0091] 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

[0092] 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

[0093] 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.

[0094] 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.

[0095] 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, direct drive mode, series mode or pure electric four-wheel drive mode.

[0096] 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.

[0097] 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.

[0098] 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 direct drive mode and a power split mode. Furthermore, by changing the gear position of the first synchronizer 105, the vehicle can switch between different driving modes. Specifically:

[0099] 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.

[0100] In direct drive mode, the first synchronizer 105 is in the engaged gear, the second synchronizer 106 is in the in-gear state, the engine 101 is in the driving state, the clutch 102 is in the closed state, the first motor 103 is usually in the driving state, and the second motor is in the driving state. At this time, the driving force output by the engine 101 will be transmitted to the transmission input shaft 107 through the first input end, the first synchronizer 105, and the output end of the power split mechanism in sequence, while the driving force output by the first motor 103 will be transmitted to the transmission input shaft 107 through the second input end and the output end of the power split mechanism. The transmission input shaft 107 then transmits this portion of the driving force to the vehicle's front axle through the second synchronizer 106, the transmission output shaft 108, and the front axle differential 109 in sequence, thereby driving the vehicle. Since in direct drive mode, the engine 101 and the first motor 103 can jointly drive the vehicle's front axle, the vehicle's driving force in direct drive mode is generally greater than that in power split mode.

[0101] It can be seen that when the vehicle switches from the power split mode to the direct drive mode, the first synchronizer 105 needs to be switched from the power split gear to the engagement gear.

[0102] In the related art, when a vehicle switches from power-split mode to direct-drive mode, it is typically necessary to first open clutch 102, then perform torque reduction and speed regulation on engine 101. After the torque reduction and speed regulation are completed, first synchronizer 105 is switched from power-split gear to engagement gear, and clutch 102 is re-engaged to complete the mode switch. However, this approach requires additional control of clutch 102 opening or closing during the mode switch process. This, on the one hand, results in a longer switching link and mode switch time. On the other hand, engine 101 must wait for clutch 102 to re-engage before it can output torque, resulting in delayed power response from engine 101, which in turn affects the vehicle's overall power response performance during the mode switch process.

[0103] In response to the problem of poor vehicle dynamic response performance when hybrid vehicles switch from power split mode to direct drive mode, the present application aims to provide a vehicle mode switching method, which first adjusts the torque of the engine 101 and the first motor 103, and then adjusts the speed of the first motor 103, so that during the vehicle mode switching process, the shifting operation of the first synchronizer 105 can be completed without opening or closing the clutch 102. In this way, the vehicle can switch from the power split mode to the direct drive mode more quickly and smoothly, effectively shortening the mode switching time while enabling the engine 101 to quickly output torque, thereby improving the vehicle's dynamic response performance during the mode switching process.

[0104] 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:

[0105] S201: When the vehicle meets the mode switching conditions for switching from the power split mode to the direct drive mode, the clutch 102 is kept in a closed state, and the engine 101 and the first motor 103 are torque-adjusted so that the first synchronizer 105 meets the torque conditions.

[0106] 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.

[0107] In this embodiment, the HCU can obtain the vehicle's operating condition information and driver operation information, and then determine whether the vehicle needs to switch from power split mode to direct drive mode based on the operating condition information and driver operation information to achieve intelligent switching of vehicle modes.

[0108] In this embodiment, after the HCU determines that the vehicle meets the mode switching conditions for switching from the power split mode to the direct drive mode, it sends 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 a closed state; at the same time, it sends an engine torque adjustment request to the engine controller, so that the engine controller responds to the engine torque adjustment request and adjusts the torque of the engine 101; at the same time, it also sends a motor torque adjustment request to the motor controller, so that the motor controller responds to the motor torque adjustment request and adjusts the torque of the first motor 103.

[0109] It should be noted that when the vehicle switches from the power split mode to the direct drive mode, the first synchronizer 105 needs to be shifted from the power split gear to the engagement gear. If the torque applied to the first synchronizer 105 is too large when the first synchronizer 105 is shifted into gear, it may cause the first synchronizer 105 to be unable to shift into gear or to be damaged when shifting into gear.

[0110] In this embodiment, to prevent the first synchronizer 105 from being unable to engage a gear smoothly, torque adjustment is performed on the engine 101 and the first motor 103 so that the torque exerted on the first synchronizer 105 by the engine 101 and the first motor 103 through the power splitting mechanism 104 is relatively small, preferably zero. In this way, the torque at the first synchronizer 105 can be reduced to the torque required for engaging a gear without disengaging the clutch 102, thereby enabling the first synchronizer 105 to meet the torque condition.

[0111] It should be noted that the torque condition is used to represent the condition under which the first synchronizer 105 can be shifted from the power split gear to the engagement gear in the torque dimension.

[0112] S202 : When the first synchronizer 105 meets the torque condition, the speed of the first motor 103 is adjusted to make the first synchronizer 105 meet the speed condition.

[0113] In this embodiment, after the HCU determines that the first synchronizer 105 meets the torque condition, it will trigger the speed adjustment for 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 to make the first synchronizer 105 meet the speed condition.

[0114] It should be noted that the first synchronizer 105 is provided between the first input end and the output end of the power splitting mechanism 104 , and is used to adjust the speed ratio between the first input end of the power splitting mechanism 104 and the transmission input shaft 107 .

[0115] In power-split mode, the first synchronizer 105 is in the power-split gear. At this point, the speed ratio between the first input end of 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 direct-drive mode, the first synchronizer 105 is required to 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.

[0116] 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 speed condition.

[0117] It should be noted that the speed condition is used to represent the conditions under which the first synchronizer 105 can be engaged from the power split gear in the speed dimension.

[0118] S203 : When the first synchronizer 105 meets the speed 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 direct drive mode.

[0119] In this embodiment, since the first synchronizer 105 has already met the torque condition in advance, after the HCU detects that the first synchronizer 105 also meets the speed condition, it will send a gear switching request for indicating that the target gear is the engagement gear to the transmission controller, so that the transmission controller responds to the gear switching request and controls the first synchronizer 105 to switch from the power split gear to the engagement gear.

[0120] In this embodiment, by first adjusting the torque of the engine 101 and the first motor 103 and then adjusting the speed of the first motor 103, the first synchronizer 105 can complete the gear shifting operation while simultaneously meeting the torque condition and the speed condition, thereby effectively ensuring the gear shifting safety of the first synchronizer 105.

[0121] 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 direct drive 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 direct drive mode.

[0122] 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 the first torque, and control the first motor 103 to output the second torque to jointly drive 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 the third torque to drive the rear axle of the vehicle.

[0123] It should be noted that the second torque output by the first motor 103 can be either positive or negative. For example, when the driver demands a high torque and the engine 101 and the second motor cannot effectively meet the user's power demand, the first motor 103 can output a positive torque to ensure the vehicle's power. When the driver demands a low torque, the first motor 103 can output a negative torque to adjust the operating point of the engine 101 so that the engine 101 can operate in the optimal economic range.

[0124] An embodiment of the present application provides a vehicle mode switching method, which first adjusts the torque of the engine 101 and the first motor 103, and then adjusts the speed of the first motor 103, so that during the vehicle mode switching process, the shifting operation of the first synchronizer 105 can be successfully completed without opening or closing the clutch 102. In this way, the vehicle can switch from the power split mode to the direct drive mode more quickly and smoothly, effectively shortening the mode switching time while enabling the engine 101 to quickly output torque, thereby improving the vehicle's power response performance during the mode switching process.

[0125] Exemplarily, the vehicle mode switching method may further include the following steps:

[0126] S301: When the vehicle is in the power split mode, obtain the current remaining power of the power battery and determine whether the driver has a strong power demand.

[0127] In this embodiment, when the vehicle is in power split mode, the HCU will obtain real-time vehicle operating condition information and driver operation information to determine whether to control the vehicle to switch from power split mode to direct drive mode. The operating condition information may specifically include the current SOC (State of Charge) of the power battery, also known as the remaining power.

[0128] In this embodiment, by detecting the current remaining power of the power battery, it is possible to effectively determine whether the power battery has sufficient remaining power to support the vehicle in direct drive mode. At the same time, by detecting the driver's operation information, it is possible to effectively determine whether the driver has a strong power demand.

[0129] In a specific implementation, the driver operation information may specifically include the current throttle opening and the current throttle opening change rate of the accelerator pedal. Furthermore, when the HCU detects that the current throttle opening is greater than an opening threshold and the current throttle opening change rate is greater than a change rate threshold, it determines that the driver has a strong power demand.

[0130] In this embodiment, by comprehensively considering the current throttle opening change rate based on the current throttle opening, the driver's strong power demand can be identified more accurately, thereby effectively avoiding the phenomenon of incorrect mode switching.

[0131] S302: When it is determined that the driver has a strong power demand and the current remaining power is greater than a power threshold, it is determined that the vehicle meets a mode switching condition for switching from a power split mode to a direct drive mode.

[0132] In this embodiment, if the HCU detects that the driver has a strong power demand and the current remaining power is greater than the power threshold, it will automatically control the vehicle to switch from power diversion mode to direct drive mode to achieve automatic switching of vehicle modes, thereby quickly and effectively meeting the driver's power demand.

[0133] For example, the step of adjusting the torque of the engine 101 and the first motor 103 in S201 may specifically include the following sub-steps:

[0134] S201 - 1 : Based on a preset torque adjustment gradient, control the current engine torque of the engine 101 and the current motor torque of the first motor 103 to follow a preset first target torque.

[0135] It should be noted that the first target torque represents the torque at which the first synchronizer 105 can shift from the power-split gear to the engagement gear. Specifically, the first target torque can be set based on actual shifting requirements. For example, to maximize the service life of the first synchronizer 105, the first target torque can be set to zero; to maximize shifting speed, the first target torque can be set to the maximum torque that can achieve gear engagement; or the first target torque can be set to a torque between zero and the maximum torque, thereby, to some extent, improving shifting speed while also ensuring the service life of the first synchronizer 105.

[0136] In this embodiment, after determining the first target torque, the HCU will activate the torque control mode of the motor controller so that the motor controller adjusts the current motor torque of the first motor 103 to the first target torque; at the same time, the HCU will also activate the torque control mode of the engine controller so that the engine controller adjusts the current engine torque of the engine 101 to the first target torque.

[0137] In a specific implementation, the current engine torque of the engine 101 and the current motor torque of the first motor 103 can gradually reach the first target torque according to a preset torque adjustment gradient. The torque adjustment gradient represents the change in torque per unit time and can be set to, for example, 200 N·m / s.

[0138] In this embodiment, by adjusting the torque of the engine 101 and the first motor 103 according to the torque adjustment gradient, it is possible to avoid a drastic change in torque that affects the driving stability of the vehicle.

[0139] Exemplarily, the vehicle further includes a second motor, and the vehicle mode switching method may further include the following steps:

[0140] S401 : Determine a compensation torque of the second motor based on the current engine torque and the current motor torque.

[0141] In this embodiment, considering that the front axle torque will continue to decrease during the torque adjustment of the engine 101 and the first motor 103, in order to ensure the power demand of the entire vehicle during the mode switching process, torque compensation will be performed by the second motor.

[0142] 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.

[0143] In one example, before torque adjustment is performed on the engine 101 and the first motor 103 , 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.

[0144] S402 : Determine a target driving torque of the second motor based on the compensation torque and the current driving torque of the second motor.

[0145] In this embodiment, the HCU will further add the compensation torque on the basis of the current driving torque of the second motor to obtain the target 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.

[0146] S403 : During the process of torque adjustment of the engine 101 and the first motor 103 , the second motor 103 is controlled to gradually increase its driving torque from the current driving torque to the target driving torque based on the torque adjustment gradient.

[0147] In this embodiment, during the process of performing torque adjustment on the engine 101 and the first motor 103 according to the torque adjustment gradient, the HCU will also synchronously control the second motor to perform torque compensation according to the same torque adjustment gradient.

[0148] In one example, the torque adjustment gradient is set to 200 N·m / s, and the first target torque is set to 0 N·m. If the HCU detects that the engine 101 outputs 800 N·m, the first motor 103 outputs -300 N·m, and the second motor outputs 400 N·m, and then detects that the vehicle meets the mode switching request, the HCU will control the engine 101 to gradually decrease from 800 N·m to 0 N·m according to the torque adjustment gradient of 200 N·m / s, and control the first motor 103 to gradually increase from -300 N·m to 0 N·m. At the same time, the compensation torque of the second motor is calculated to be 500 N·m, and the target drive torque is 900 N·m. Then, the second motor is synchronously controlled to gradually increase from 400 N·m to 900 N·m according to the torque adjustment gradient of 200 N·m / s.

[0149] 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.

[0150] Exemplarily, the vehicle mode switching method may further include the following steps:

[0151] S501 : When a first torque difference between a current engine torque and a first target torque is smaller than a first torque threshold, triggering timing of a first duration during which the first torque difference is smaller than the first torque threshold.

[0152] 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 first torque difference between the current engine torque and the first target torque is less than the first torque threshold, the first timer is triggered to accumulate timing for the first duration, and then based on the first duration, it is determined whether the engine 101 is stably operating at the first target torque.

[0153] S502 : When a second torque difference between the current motor torque and the first target torque is smaller than a second torque threshold, trigger timing of a second duration for which the second torque difference is smaller than the second torque threshold.

[0154] In this embodiment, during the process of torque regulation of the first motor 103, the HCU will obtain the current motor torque of the first motor 103 fed back in real time by the motor controller, and then, when it detects that the second torque difference between the current motor torque and the first target torque is less than the second torque threshold, the second timer is triggered to accumulate timing for the second duration, and then based on the second duration, it is determined whether the first motor 103 is stably operating at the first target torque.

[0155] S503 : 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 105 meets the torque condition.

[0156] In this embodiment, if the HCU detects that the first duration and the second duration are both greater than their respective corresponding duration thresholds, it is considered that the engine 101 and the first motor 103 are both stably operating at the first target torque, and further determines that the first synchronizer 105 has met the torque condition.

[0157] In this embodiment, by monitoring the first duration and the second duration, it is possible to effectively avoid controlling the first synchronizer 105 to perform a gear shifting operation when there is abnormal torque fluctuation in the engine 101 or the first motor 103, thereby ensuring the gear shifting safety of the first synchronizer 105.

[0158] 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.

[0159] It should be noted that, 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 in sequence through multiple planetary gears 1043 and the sun gear 1042 to the first motor 103 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 in sequence through multiple planetary gears 1043, the ring gear 1041, the gearbox input shaft 107, the second synchronizer 106, the gearbox output shaft 108 and the front axle differential 109 to the front axle of the vehicle to drive the vehicle.

[0160] In direct drive 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. The driving force output by the engine 101 will be transmitted to the transmission input shaft 107 through the planetary carrier 1044, the first synchronizer 105 and the ring gear 1041 in sequence, and the driving force output by the first motor 103 will be transmitted to the transmission input shaft 107 through the sun gear 1042, multiple planetary gears 1043 and the ring gear 1041, that is, the engine 101 and the first motor 103 transmit the driving force to the transmission input shaft 107 together through two different power paths, and then the transmission input shaft 107 transmits this part of the driving force to the 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.

[0161] Based on the above structure, the step of adjusting the speed of the first motor 103 in S202 may specifically include the following sub-steps:

[0162] S202 - 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 first speed ratio.

[0163] 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 two gears must be adjusted to ensure that the speed difference between the two ends of the first synchronizer 105 is less than a predetermined speed difference threshold. Furthermore, since the planetary carrier 1044 is connected to the engine 101, the speed of the planetary carrier 1044 is the engine speed. Furthermore, since the ring gear 1041 is connected to the first motor 103 via the plurality of planetary gears 1043, the sun gear 1042, and the first motor 103, the speed of the ring gear 1041 can be converted to the speed of the first motor 103. This allows the speed of the first synchronizer 105 to be adjusted to meet the speed requirement while maintaining the engine speed.

[0164] In this embodiment, considering that the speed ratio between the planetary carrier 1044 and the ring gear 1041 is different at different gears of the first synchronizer 105, the speed ratio between the planetary carrier 1044 and the ring gear 1041 will be determined as the first speed ratio based on the current gear of the first synchronizer 105.

[0165] S202 - 2 : Determine a target ring gear speed of the ring gear 1041 based on the current engine speed of the engine 101 and the first speed ratio.

[0166] In this embodiment, the HCU uses the current engine speed of the engine 101 as a speed control reference to control the speed of the first motor 103, thus eliminating the need to adjust the engine speed. Furthermore, based on the current engine speed of the engine 101 and the first gear ratio, the target ring gear speed of the ring gear 1041 can be determined.

[0167] S202 - 3 : Determine a target motor speed of the first motor 103 based on the target ring gear speed and the second speed ratio between the ring gear 1041 and the sun gear 1042 .

[0168] In this embodiment, according to the second speed ratio between the ring gear 1041 and the sun gear 1042 , the target ring gear speed can be further converted into a target motor speed required by the first motor 103 .

[0169] In a specific implementation, the target motor speed can be calculated according to the following formula: n1=n0×i1×i2 (1);

[0170] Among them, n1 represents the target motor speed of the first motor 103, n0 represents the current engine speed of the engine 101, i1 represents the first speed ratio, which represents the speed ratio between the planetary carrier 1044 and the ring gear 1041 when the first synchronizer 105 is in the power split gear, and i2 represents the second speed ratio between the ring gear 1041 and the sun gear 1042.

[0171] S202 - 4 : Control the current motor speed of the first motor 103 to follow the target motor speed.

[0172] In this embodiment, when the HCU sends a speed control request including the target motor speed 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, thereby achieving precise control of the speed of the first motor 103.

[0173] 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.

[0174] 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.

[0175] 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.

[0176] In a feasible implementation manner, the vehicle mode switching method may further include the following steps:

[0177] S601: Determine a current ring gear speed of the ring gear based on the current motor speed and the second speed ratio.

[0178] 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 .

[0179] S602: Determine a current planetary carrier rotational speed of the planetary carrier based on the current engine torque.

[0180] 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.

[0181] S603 : 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 speed condition.

[0182] 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 speed condition.

[0183] In this embodiment, by monitoring the speed difference between the two ends of the first synchronizer 105 in real time, the shifting safety of the first synchronizer 105 can be effectively guaranteed.

[0184] Exemplarily, S203 may specifically include the following sub-steps:

[0185] S203 - 1 : When the first synchronizer 105 meets the speed condition, the sum of the first target torque and the preset shift assist torque is determined as the second target torque.

[0186] 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, an engaging assist torque is added to the first target torque, and the first motor 103 is controlled to output a second target torque, so that the first motor 103 can assist the first synchronizer 105 in smoothly completing the shift operation. The engaging assist torque can be set to 2 N·m.

[0187] S203 - 1 : Control the current motor torque of the first motor 103 to follow the second target torque, so as to assist the first synchronizer 105 in switching from the power split gear to the engagement gear.

[0188] In a specific implementation, the HCU sends a second motor torque adjustment request including the second target torque to the motor controller, causing the motor controller to adjust the torque of the first motor 103 in response to the second motor torque adjustment request so that the first motor 103 outputs the second target torque. When the first target torque is set to zero, the second target torque is the shift assist torque.

[0189] In this embodiment, by controlling the first motor 103 to further superimpose the gear-shifting auxiliary torque on the basis of the first target torque, the first synchronizer 105 can effectively improve the gear shifting efficiency under the auxiliary drive of the first motor 103, while avoiding the gear shifting failure of the first synchronizer 105.

[0190] 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 first synchronizer 105 , and a gearbox input shaft 107 . 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 , and the first synchronizer 105 is disposed between the first input end and the output end. The vehicle mode switching device 300 includes:

[0191] The torque adjustment module 301 is configured to maintain the clutch 102 in a closed state and adjust the torque of the engine 101 and the first motor 103 so that the first synchronizer 105 meets the torque condition when the vehicle meets the mode switching condition for switching from the power split mode to the direct drive mode;

[0192] The speed regulating module 302 is configured to regulate the speed of the first motor 103 when the first synchronizer 105 satisfies the torque condition, so that the first synchronizer 105 satisfies the speed condition;

[0193] The gear switching module 303 is used to control the first synchronizer 105 to switch from the power split gear to the engagement gear when the first synchronizer 105 meets the speed condition, so as to switch the vehicle from the power split mode to the direct drive mode.

[0194] Exemplarily, the vehicle mode switching device 300 further includes:

[0195] The information acquisition submodule is used to obtain the current remaining power of the power battery and determine whether the driver has a strong power demand when the vehicle is in power split mode;

[0196] The condition determination submodule is used to determine whether the vehicle meets the mode switching conditions for switching from the power split mode to the direct drive mode when it is determined that the driver has a strong power demand and the current remaining power is greater than the power threshold.

[0197] Exemplarily, the information acquisition submodule includes:

[0198] A pedal information acquisition unit, configured to acquire the current throttle opening and the current throttle opening change rate of the throttle pedal;

[0199] The power demand determination unit is used to determine that the driver has a strong power demand when the current throttle opening is greater than the opening threshold and the current throttle opening change rate is greater than the change rate threshold.

[0200] Exemplarily, the torque adjustment module 301 includes:

[0201] The torque regulation submodule is configured to control the current engine torque of the engine 101 and the current motor torque of the first motor 103 to follow a preset first target torque based on a preset torque regulation gradient.

[0202] Exemplarily, the vehicle further includes a second motor, and the vehicle mode switching device 300 further includes:

[0203] 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;

[0204] 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;

[0205] 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 and the first motor 103 .

[0206] Exemplarily, the vehicle mode switching device 300 further includes:

[0207] a first timing module, configured to trigger timing of a first duration of time during which the first torque difference is less than the first torque threshold when a first torque difference between the current engine torque and the first target torque is less than a first torque threshold;

[0208] a second timing module, configured to trigger timing of a second duration of time during which the second torque difference is less than the second torque threshold when a second torque difference between the current motor torque and the first target torque is less than a second torque threshold;

[0209] The first condition determination module is configured to determine that the second synchronizer 106 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.

[0210] Exemplarily, the power split mechanism 104 includes a ring gear, a sun gear, a plurality of planetary gears meshed between the ring gear and the sun gear, and a planet carrier rotatably connected to the plurality of planetary gears; the planet carrier 1044 is connected to the engine 101 as a first input end of the power split mechanism 104, the sun gear 1042 is connected to the first motor 103 as a second input end of the power split mechanism 104, the ring gear 1041 is connected to the transmission input shaft 107 as an output end of the power split mechanism 104, and the first synchronizer 105 is disposed between the planet carrier 1044 and the ring gear 1041; the speed regulation module 302 includes:

[0211] a speed ratio determination submodule, configured to determine the speed ratio between the planet carrier and the ring gear as the first speed ratio when the current gear position of the first synchronizer 105 is the power split gear;

[0212] a target ring gear speed determination submodule, configured to determine a target ring gear speed of the ring gear based on a current engine speed of the engine 101 and the first gear ratio;

[0213] a motor speed determination submodule, configured to determine a target motor speed of the first motor 103 based on the target ring gear speed and a second speed ratio between the ring gear and the sun gear;

[0214] The motor speed control submodule is used to control the current motor speed of the first motor 103 to follow the target motor speed.

[0215] Exemplarily, the vehicle mode switching device 300 further includes:

[0216] a current ring gear speed determining module, configured to determine a current ring gear speed of the ring gear based on a current motor speed and a second speed ratio;

[0217] a current planet carrier speed determining module, configured to determine a current planet carrier speed of the planet carrier based on a current engine torque;

[0218] The second condition determination module is configured to determine that the first synchronizer 105 meets the speed condition when the speed difference between the current ring gear speed and the current planet carrier speed is less than a speed difference threshold.

[0219] Exemplarily, the gear switching module 303 includes:

[0220] a target torque determination submodule, configured to determine the sum of the first target torque and a preset shift assist torque as a second target torque when the first synchronizer 105 satisfies a speed condition;

[0221] The gear shift submodule is configured to control the current motor torque of the first motor 103 to follow the second target torque, so as to assist the first synchronizer 105 in switching from the power split gear to the engagement gear.

[0222] 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.

[0223] 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 first synchronizer 105 and a gearbox input shaft 107, the engine 101 is connected to the first input end of the power splitting mechanism 104 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, 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.

[0224] The vehicle controller 401 is configured to send a clutch state maintaining request to the transmission controller 402, an engine torque adjustment request to the engine controller 404, and a motor torque adjustment request to the motor controller 403 when the vehicle meets the mode switching conditions for switching from the power split mode to the direct drive mode;

[0225] The transmission controller 402 is configured to keep the clutch 102 in a closed state in response to the clutch state keeping request;

[0226] The engine controller 404 is used to adjust the torque of the engine 101 in response to the engine torque adjustment request. The motor controller 403 is used to adjust the torque of the first motor 103 in response to the motor torque adjustment request so that the first synchronizer 105 meets the torque condition.

[0227] The vehicle controller 401 is further configured to send a speed adjustment request to the motor controller 403 when the first synchronizer 105 meets the torque condition;

[0228] The motor controller 403 is further configured to adjust the speed of the first motor 103 in response to the speed adjustment request so that the first synchronizer 105 meets the speed condition;

[0229] The vehicle controller 401 is further configured to send a gear shift request to the transmission controller 402 when the first synchronizer 105 meets the speed condition;

[0230] The transmission controller 402 is further configured to control the first synchronizer 105 to switch from the power split gear to the engagement gear in response to a gear shift request, so as to switch the vehicle from the power split mode to the direct drive mode.

[0231] 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.

[0232] 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.

[0233] 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.

[0234] 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.

[0235] 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.

[0236] 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.

[0237] 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.

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 splitting mechanism, a first synchronizer, and a transmission input shaft. The engine is connected to a first input end of the power splitting mechanism through the clutch, the first motor is connected to a second input end of the power splitting mechanism, an output end of the power splitting mechanism is connected to the transmission input shaft, and the first synchronizer is arranged between the first input end and the output end; the method includes: When the vehicle meets the mode switching condition for switching from the power splitting mode to the direct drive mode, keep the clutch in a closed state, and adjust the torques of the engine and the first motor so that the first synchronizer meets the torque condition; When the first synchronizer meets the torque condition, adjust the speed of the first motor so that the first synchronizer meets the speed condition; When the first synchronizer meets the speed condition, control the first synchronizer to switch from the power splitting gear to the engaged gear so that the vehicle switches from the power splitting mode to the direct drive mode.

2. The vehicle mode switching method according to claim 1, wherein The method further includes: When the vehicle is in the power splitting mode, obtain the current remaining power of the power battery and determine whether the driver has a strong power demand; When it is determined that the driver has the strong power demand and the current remaining power is greater than the power threshold, determine that the vehicle meets the mode switching condition for switching from the power splitting mode to the direct drive mode.

3. The vehicle mode switching method according to claim 2, characterized in that The step of determining whether the driver has a strong power demand includes: Obtain the current throttle opening and the current throttle opening change rate of the throttle pedal; When the current throttle opening is greater than the opening threshold and the current throttle opening change rate is greater than the change rate threshold, determine that the driver has a strong power demand.

4. The vehicle mode switching method according to claim 1, wherein The step of adjusting the torques of the engine and the first motor includes: Based on a preset torque adjustment gradient, control the current engine torque of the engine and the current motor torque of the first motor to follow a preset first target torque.

5. The vehicle mode switching method according to claim 4, 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 torques of the engine and the first motor, based on the torque adjustment gradient, control the second motor to gradually increase from the current driving torque to the target driving torque.

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

7. 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 arranged between the planet carrier and the ring gear; The step of adjusting the speed of the first motor 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 first speed ratio; Based on the current engine speed of the engine and the first speed ratio, determining the target ring gear speed of the ring gear; Based on the target ring gear speed and the second speed ratio between the ring gear and the sun gear, determining the target motor speed of the first motor; Controlling the current motor speed of the first motor to follow the target motor speed.

8. The vehicle mode switching method according to claim 7, wherein, The method further includes: Based on the current motor speed and the second speed ratio, determining the current ring gear speed of the ring gear; Based on the current engine torque, determining the current planet carrier speed of the planet carrier; When the speed difference between the current ring gear speed and the current planet carrier speed is less than the speed difference threshold, it is determined that the first synchronizer meets the speed condition.

9. The vehicle mode switching method according to claim 4, characterized in that, When the first synchronizer meets the speed condition, the step of controlling the first synchronizer to switch from the power split gear position to the engaged gear position includes: When the first synchronizer meets the speed condition, determining the sum of the first target torque and the preset shift assist torque as the second target torque; Controlling the current motor torque of the first motor to follow the second target torque to assist the first synchronizer to switch from the power split gear position to the engaged gear position.

10. 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 first synchronizer, and a transmission input shaft. 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, and the first synchronizer is arranged between the first input end and the output end; the device includes: A torque adjustment module, configured to keep the clutch in a closed state and adjust the torques of the engine and the first motor when the vehicle meets the mode switching condition for switching from the power split mode to the direct drive mode, so that the first synchronizer meets the torque condition; A speed adjustment module, configured to adjust the speed of the first motor when the first synchronizer meets the torque condition, so that the first synchronizer meets the speed condition; The gear shift module is configured to control the first synchronizer to shift from the power split gear to the engaged gear when the first synchronizer meets the rotational speed condition, so as to switch the vehicle from the power split mode to the direct drive mode.

11. 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 first synchronizer, and a transmission input shaft. 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, and the first synchronizer is arranged 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 send a clutch state holding request to the transmission controller, an engine torque adjustment request to the engine controller, and a motor torque adjustment request to the motor controller when the vehicle meets the mode switching condition for switching from the power split mode to the direct drive mode; The transmission controller is configured to keep the clutch in a closed state in response to the clutch state holding request; The engine controller is configured to adjust the torque of the engine in response to the engine torque adjustment request, and the motor controller is configured to adjust the torque of the first motor in response to the motor torque adjustment request, so that the first synchronizer meets the torque condition; The vehicle controller is further configured to send a rotational speed adjustment request to the motor controller when the first synchronizer meets the torque condition; The motor controller is further configured to adjust the rotational speed of the first motor in response to the rotational speed adjustment request, so that the first synchronizer meets the rotational speed condition; The vehicle controller is further configured to send a gear shift request to the transmission controller when the first synchronizer meets the rotational speed condition; The transmission controller is further configured to control the first synchronizer to shift from the power split gear to the engaged gear in response to the gear shift request, so as to switch the vehicle from the power split mode to the direct drive mode.

12. A vehicle, characterized in that, It includes the vehicle mode switching system as described in claim 11.

13. 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 1-9.

14. A computer-readable medium, characterized in that, It stores the computer program as described in claim 13.

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