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

Abstract

The present application belongs to the technical field of vehicle control. Provided are a vehicle mode switching method, apparatus and system, and a vehicle, a computer program and a readable medium. In the embodiments of the present application, when it is determined that a driver has the intent of reversing, by means of identifying operating condition information of a vehicle, whether the vehicle meets a mode switching condition for switching from a series mode to a power-split mode can be accurately determined; thus, when the vehicle meets the mode switching condition, a clutch can be kept in an engaged state, and a first electric motor can be kept in a power generation state; and torque regulation is performed on an engine, and then rotation speed regulation is performed on the first electric motor, so that in the process of vehicle mode switching, gear shifting operations of a first synchronizer and a second synchronizer can be sequentially completed while the clutch is not disengaged and the first electric motor is kept generating power. In this way, in the process of mode switching, an engine can continuously drive a first electric motor to charge a power battery, and the mode switching duration can also be effectively shortened, thereby improving the power response performance of vehicles, and thus realizing rapid reversing.

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 202311866447.2 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 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 switching from series mode (when driving straight ahead) to power-split mode (when reversing), the vehicle typically first opens the clutch, then performs torque reduction and speed regulation on the engine and motor. After these operations are complete, the clutch is re-engaged to complete the mode switch. However, due to the clutch opening and closing process, this method not only prevents the engine from driving the motor to charge the power battery after the clutch is opened, but also results in a longer mode switch time and untimely engine power response, which in turn affects the vehicle's mode switching process. Summary of the Invention

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

[0006] In a first aspect, an embodiment of the present application provides a vehicle mode switching method, wherein the vehicle includes an engine, a clutch, a first motor, and a gearbox; the gearbox 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:

[0007] If it is determined that the driver has a reverse intention, determining whether the vehicle meets a mode switching condition for switching from the series mode to the power split mode based on the operating condition information of the vehicle;

[0008] When it is determined that the vehicle meets the mode switching condition, the clutch is kept in a closed state, the first motor is in a generating state, and the engine torque is adjusted so that the first synchronizer meets the first gear switching condition;

[0009] When the first synchronizer satisfies the first gear shifting condition, the first synchronizer is controlled to switch from the engagement gear to the power split gear; and the speed of the first motor is adjusted 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 the current gear to the reverse gear, so that the vehicle switches from the series mode to the power split mode.

[0011] In some embodiments of the present application, the operating condition information includes the current driving mode, the current road condition, and the current remaining power of the power battery;

[0012] The step of determining whether the vehicle satisfies a mode switching condition for switching from a series mode to a power split mode based on the operating condition information of the vehicle includes:

[0013] When the current driving mode is the series mode, the current road condition is a preset road condition, and the current remaining power is less than a power threshold, it is determined that the vehicle meets the mode switching condition for switching from the series mode to the power split mode.

[0014] 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;

[0015] The step of adjusting the torque of the engine comprises:

[0016] When the current gear position of the first synchronizer is the engagement gear, determining the speed ratio between the sun gear and the planet carrier to be a first speed ratio;

[0017] determining a target engine torque of the engine based on the raw motor torque of the first motor and the first speed ratio;

[0018] Based on a preset torque adjustment gradient, the engine is controlled to gradually reduce the original engine torque to the target engine torque.

[0019] In some embodiments of the present application, the vehicle further includes a second motor, and the method further includes:

[0020] determining a compensation torque for the second electric machine based on the raw engine torque and the raw electric machine torque;

[0021] determining a target driving torque of the second motor based on the compensation torque and an original driving torque of the second motor;

[0022] During the process of torque regulation of the engine, the second motor is controlled to gradually increase from the original driving torque to the target driving torque based on the torque regulation gradient.

[0023] In some embodiments of the present application, the method further comprises:

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

[0025] When the first duration is greater than a first duration threshold, it is determined that the first synchronizer meets the first gear shift condition.

[0026] In some embodiments of the present application, the step of adjusting the speed of the first motor includes:

[0027] determining a target motor speed of the first motor based on a current wheel speed of a target wheel, a current gear position of the first synchronizer, and a target gear position of the second synchronizer;

[0028] The current motor speed of the first motor is controlled to follow the target motor speed.

[0029] In some embodiments of the present application, the step of determining the target motor speed of the first motor based on the current wheel speed of the target wheel, the current gear position of the first synchronizer, and the target gear position of the second synchronizer includes:

[0030] When the current gear position of the first synchronizer is the power split gear, determining the speed ratio between the sun gear and the ring gear to be a second speed ratio;

[0031] When the target gear position of the second synchronizer is the reverse gear, determining the speed ratio between the transmission input shaft and the target wheel to be a third speed ratio;

[0032] determining a fourth speed ratio between the target wheel and the first motor based on the second speed ratio and the third speed ratio;

[0033] 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.

[0034] In some embodiments of the present application, the method further comprises:

[0035] When the current motor speed of the first motor reaches the target motor speed, triggering timing of a second duration during which the fluctuation amplitude of the current motor speed is less than a speed threshold;

[0036] When the second duration is greater than a second duration threshold, it is determined that the second synchronizer meets the second gear shift condition.

[0037] In a second aspect, an embodiment of the present application provides a vehicle mode switching device, the vehicle comprising an engine, a clutch, a first motor, and a gearbox; the gearbox comprising: a power split mechanism, a gearbox input shaft, a gearbox output shaft, a first synchronizer, and a second synchronizer; the engine is connected to a first input end of the power split mechanism via the clutch, the first motor is connected to a second input end of the power split mechanism, the output end of the power split mechanism is connected to the gearbox input shaft, the second synchronizer is disposed between the gearbox input shaft and the gearbox output shaft, and the first synchronizer is disposed between the first input end and the output end; the device comprises:

[0038] a condition determination module, configured to determine, based on the operating condition information of the vehicle, whether the vehicle satisfies a mode switching condition for switching from the series mode to the power split mode when it is determined that the driver has a reverse intention;

[0039] a torque adjustment module, configured to, upon determining that the vehicle satisfies the mode switching condition, maintain the clutch in a closed state, the first motor in a generating state, and adjust the engine torque so that the first synchronizer satisfies the first gear switching condition;

[0040] 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 speed of the first motor so that the second synchronizer satisfies the second gear switching condition;

[0041] The mode switching module is configured to control the second synchronizer to switch from the current gear to the reverse 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.

[0042] In some embodiments of the present application, the operating condition information includes the current driving mode, the current road condition, and the current remaining power of the power battery; the condition determination module includes:

[0043] The switching condition determination submodule is used to determine that the vehicle meets the mode switching conditions for switching from the series mode to the power split mode when the current driving mode is the series mode, the current road condition is the preset road condition, and the current remaining power is less than the power threshold.

[0044] 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 torque regulation module includes:

[0045] a speed ratio determining submodule, configured to determine, when the current gear position of the first synchronizer is the engagement gear, the speed ratio between the sun gear and the planet carrier as a first speed ratio;

[0046] an engine torque determination submodule, configured to determine a target engine torque of the engine based on an original motor torque of the first motor and the first speed ratio;

[0047] The engine torque control submodule is configured to control the engine to gradually reduce the original engine torque to the target engine torque based on a preset torque adjustment gradient.

[0048] In some embodiments of the present application, the vehicle mode switching device further includes:

[0049] a compensation torque determination module, configured to determine a compensation torque for the second motor based on the original engine torque and the original motor torque;

[0050] a driving torque determination module for determining a target driving torque of the second motor based on the compensation torque and an original driving torque of the second motor;

[0051] The driving torque control module is configured to control the second motor to gradually increase the original driving torque to the target driving torque based on the torque adjustment gradient during the process of adjusting the torque of the engine.

[0052] In some embodiments of the present application, the vehicle mode switching device further includes:

[0053] a first timing module, configured to trigger timing of a first duration of time during which the torque difference between the current engine torque of the engine and the target engine torque is less than a torque threshold when the torque difference between the current engine torque and the target engine torque is less than a torque threshold;

[0054] 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.

[0055] In some embodiments of the present application, the speed adjustment module includes:

[0056] a motor speed determination submodule, configured to determine a target motor speed of the first motor based on a current wheel speed of a target wheel, a current gear position of the first synchronizer, and a target gear position of the second synchronizer;

[0057] The motor speed control submodule is used to control the current motor speed of the first motor to follow the target motor speed.

[0058] In some embodiments of the present application, the motor speed determination submodule includes:

[0059] 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 sun gear and the ring gear is a second speed ratio;

[0060] a second speed ratio determining unit, configured to determine, when the target gear position of the second synchronizer is the reverse gear, that the speed ratio between the transmission input shaft and the target wheel is a third speed ratio;

[0061] 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 and the third speed ratio;

[0062] 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.

[0063] In some embodiments of the present application, the vehicle mode switching device further includes:

[0064] a second timing module, configured to trigger timing of a second duration during which a 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;

[0065] The second condition determination module is configured to determine that the second synchronizer satisfies the second gear shift condition when the second duration is greater than a second duration threshold.

[0066] 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 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,

[0067] The vehicle controller is configured to, upon determining that the driver has an intention to reverse, determine, based on the vehicle's operating condition information, whether the vehicle satisfies a mode switching condition for switching from a series mode to a power split mode; and, upon determining that the vehicle satisfies the mode switching condition, send an engine torque adjustment request to the engine controller, send a clutch state maintaining request to the transmission controller, and send a motor state maintaining request to the motor controller;

[0068] The transmission controller is configured to maintain the clutch in a closed state in response to the clutch state maintaining request; the motor controller is configured to maintain the first motor in a power generation state in response to the motor state maintaining request;

[0069] The engine controller is configured to adjust the engine torque in response to the engine torque adjustment request so that the first synchronizer satisfies a first gear shift condition;

[0070] The vehicle controller is further configured to send a first gear shift request to the transmission controller and a motor speed adjustment request to the motor controller when the first synchronizer satisfies the first gear shift condition;

[0071] The transmission controller is further configured to control the first synchronizer to switch from the engagement gear to the power split gear in response to the first gear shift request; the motor controller is further configured to adjust the speed of the first motor in response to the motor speed adjustment request so that the second synchronizer meets the second gear shift condition;

[0072] The vehicle controller is further configured to send a second gear shift request to the transmission controller when the second synchronizer satisfies the second gear shift condition;

[0073] The transmission controller is further configured to control the second synchronizer to shift from a current gear to a reverse gear in response to the second gear shift request, so as to switch the vehicle from the series mode to the power split mode.

[0074] In a fourth aspect, an embodiment of the present application provides a vehicle, including the vehicle mode switching system proposed in the third aspect of the present application.

[0075] 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.

[0076] 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.

[0077] Compared with the prior art, this application has the following advantages:

[0078] An embodiment of the present application provides a vehicle mode switching method, which determines whether the vehicle meets the mode switching conditions for switching from the series mode to the power split mode based on the vehicle's operating condition information when it is determined that the driver has the intention to reverse. When it is determined that the vehicle meets the mode switching conditions, the clutch is kept in a closed state, the first motor is in a generating state, and the engine is torque-adjusted so that when the first synchronizer meets the first gear switching condition, the first synchronizer can be controlled to switch from the engagement gear to the power split gear; and by adjusting the speed of the first motor, when the second synchronizer meets the second gear switching condition, the second synchronizer can be controlled to switch from the current gear to the reverse gear, so that the vehicle switches from the series mode to the power split mode.

[0079] The embodiment of the present application can control the vehicle to automatically switch from series mode to power split mode by identifying the vehicle's operating condition information when the driver has the intention to reverse. At the same time, by adjusting the torque of the engine and then adjusting the speed of the first motor, during the vehicle mode switching process, the shifting operations of the first synchronizer and the second synchronizer can be completed in sequence without opening the clutch and keeping the first motor generating electricity. In this way, the engine can not only continue to drive the first motor to charge the power battery, but also enable the vehicle to switch more quickly and smoothly from series mode to power split mode in the reverse state, while meeting the charging needs of the power battery, effectively shortening the mode switching time, allowing the engine to quickly output torque and achieve rapid reversing, thereby effectively improving the vehicle's power response performance during the mode switching process.

[0080] 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

[0081] 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.

[0082] FIG1 is a schematic structural diagram of a hybrid vehicle in an embodiment of the present application.

[0083] FIG2 is a flowchart of the steps of a vehicle mode switching method in an embodiment of the present application.

[0084] FIG3 is a schematic diagram of functional modules of a vehicle mode switching device in an embodiment of the present application.

[0085] FIG4 is a schematic structural diagram of a vehicle mode switching system in an embodiment of the present application.

[0086] FIG5 is a schematic structural diagram of a vehicle in an embodiment of the present application.

[0087] 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

[0088] 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

[0089] 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.

[0090] 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.

[0091] 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.

[0092] 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.

[0093] 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.

[0094] The hybrid vehicle using the above architecture is equipped with a power split mechanism 104, which is connected to the engine 101, the first motor 103, and the transmission input shaft 107. This allows the vehicle to have multiple driving modes, including a series mode and a power split mode. Furthermore, by changing the gear position of the first synchronizer 105 and the second synchronizer 106, the vehicle can switch between different driving modes. Specifically:

[0095] 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.

[0096] 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.

[0097] Specifically, when the vehicle is reversing in the power split mode, the second synchronizer 106 is in the R gear (reverse gear). At this time, the R gear is reversed to achieve vehicle reversal; when the vehicle is moving straight in the series mode, the second synchronizer 106 is in the D gear (forward gear), such as D1 (first gear), D2 (second gear) or D3 (third gear).

[0098] In related technologies, depending on road conditions and driving demands, a hybrid vehicle may need to switch from a series mode in straight-ahead driving to a power-split mode in reverse. In conventional vehicle mode switching strategies, the vehicle first needs to disengage the clutch 104, then perform torque reduction and speed regulation on the engine 101 and the first motor 103. After the torque reduction and speed regulation are complete, the clutch 104 is re-engaged to complete the mode switch. However, due to the process of opening and closing the clutch 104, this approach not only results in the engine 101 being unable to drive the first motor 103 to charge the power battery after the clutch 104 is opened, but also results in a longer mode switch time and untimely power response from the engine 101, thereby affecting the vehicle's power response performance during the mode switch.

[0099] In response to the problem that the current hybrid vehicle interrupts the charging process of the power battery and has poor vehicle dynamic response performance when switching from series mode to power split mode in reverse, the present application aims to provide a vehicle mode switching method, device, system, vehicle, computer program and computer-readable medium, which can keep the clutch 102 in a closed state and the first motor 103 in a power generation state, and by adjusting the torque of the engine 101 and then adjusting the speed of the first motor 103, during the vehicle mode switching process, the second synchronizer 106 and the first synchronizer 105 can be completed in sequence without opening the clutch 102. In this way, the engine 101 can not only continue to drive the first motor 103 to charge the power battery, but also enable the vehicle to switch from the power split mode to the series mode more quickly and smoothly in reverse, while meeting the charging needs of the power battery, effectively shortening the mode switching time, allowing the engine 101 to quickly output torque, and improving the vehicle's dynamic response performance during the mode switching process.

[0100] 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:

[0101] S201: When it is determined that the driver has a reverse intention, determine whether the vehicle meets a mode switching condition for switching from the series mode to the power split mode based on the vehicle's operating condition information.

[0102] It should be noted that the execution entity of this embodiment can be a computing service device with data processing, network communication, and program execution functions, or an electronic device with the above functions, such as a driving computer, an onboard computer, etc., such as an ECU (Electronic Control Unit), a BCM (Body Control Module), or an HCU (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.

[0103] In this embodiment, the HCU can detect the position of the vehicle's gear lever to determine whether the driver has a reverse intention. For example, if the HCU detects that the gear lever has switched from the current position to the reverse position, the HCU determines that the driver has a reverse intention. The current position can be the neutral position or the park position.

[0104] For example, after determining that the driver intends to reverse, the HCU will obtain the vehicle's operating condition information, and then based on the operating condition information, determine whether the vehicle needs to switch from the series mode to the power split mode in the reverse state.

[0105] In a specific implementation, operating condition information may include the current driving mode, current road conditions, and the current SOC (State of Charge) of the power battery. The HCU determines that the vehicle meets the conditions for switching from series mode to power split mode when the current driving mode is series mode, the current road conditions are preset, and the current remaining battery capacity is less than a threshold. The current road conditions can be determined based on the perception system's perception of the road surface and driving status information, including the current vehicle speed and acceleration.

[0106] It should be noted that the preset road condition represents a road condition that requires the vehicle to be in four-wheel drive mode, such as desert road conditions, muddy road conditions and snowy road conditions; the power threshold represents the charging balance point of the power battery, for example, it can be set to 20%, that is, when the current SOC of the power battery is less than 20%, it means that before the mode is switched, that is, in the series mode, the remaining power of the power battery has not been charged to above the charging balance point. Therefore, after the vehicle enters the reverse state, the charging demand of the power battery still needs to be met, that is, the vehicle is controlled to perform the power diversion mode in the reverse state.

[0107] In this embodiment, by analyzing the operating condition information when the driver intends to reverse, the vehicle can be controlled to automatically switch from series mode to power split mode, thereby effectively meeting the driver's driving needs under preset road conditions while meeting the charging needs of the power battery.

[0108] S202: When it is determined that the vehicle meets the mode switching condition, the clutch 102 is kept in a closed state, the first motor is in a power generation state, and the engine 101 is torque-regulated so that the first synchronizer 105 meets the first gear switching condition.

[0109] In this embodiment, after determining that the vehicle meets the mode switching conditions, the HCU 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, the HCU sends a motor state maintaining request to the motor controller, so that the motor controller responds to the motor state maintaining request and keeps the first motor 103 in a power generation state, that is, keeps the original power generation torque unchanged; at the same time, the HCU also 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.

[0110] 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.

[0111] In this embodiment, considering that when the clutch 102 is closed, the torque 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 engine torque of the engine 101, the torque applied by the engine 101 to the power split mechanism 104 can be used to offset the torque applied by the first motor to the power split mechanism 104, and then the torque of the power split mechanism 104 acting on the first synchronizer 105 can be adjusted. In this way, the torque output by the first synchronizer 105 can be balanced to the torque required for shifting the gear without opening the clutch 102 and without reducing the torque of the first motor, so that the first synchronizer 105 meets the first gear switching condition.

[0112] S203 : 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 speed of the first motor is adjusted to make the second synchronizer 106 meet the second gear switching condition.

[0113] 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 request for indicating that the target gear is the power split gear to the transmission controller, so that the transmission controller responds to the first gear request and controls the first synchronizer 105 to shift gears to the power split gear.

[0114] 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 motor speed adjustment request including the target motor speed to the motor controller, so that the motor controller responds to the motor speed adjustment request and adjusts the current motor speed of the first motor 103 based on the target motor speed so that the second synchronizer 106 meets the second gear switching condition.

[0115] 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. Before the second synchronizer 106 is engaged from the current gear into reverse gear, the speed difference across the second synchronizer 106 must be adjusted to a minimum value, ideally zero. Since the vehicle also passes through neutral when shifting from forward gear to reverse gear, the current gear can be set to neutral.

[0116] For example, considering that the first motor 103 is connected to the power splitting mechanism 104 and the torque balance of the first motor has been achieved by using the engine 101, therefore, by adjusting the speed of the first motor 103, the speed of the transmission input shaft 107 can also be adjusted without opening the clutch 102 and keeping the first motor generating electricity, so that the second synchronizer 106 meets the second gear switching condition.

[0117] S204 : When the second synchronizer 106 satisfies the second gear switching condition, the second synchronizer 106 is controlled to switch from the current gear to the reverse gear, so that the vehicle switches from the series mode to the power split mode.

[0118] In this embodiment, after detecting that the second synchronizer 106 meets the second gear switching condition, the HCU will send a second gear request including a target gear being a reverse gear to the transmission controller, so that the transmission controller responds to the second gear request and controls the second synchronizer 106 to switch from the current gear to the reverse gear.

[0119] 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 engine 101, the first motor 103 and the second motor to output torque according to the torque distribution strategy in the power split mode to drive the vehicle to reverse.

[0120] 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.

[0121] 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.

[0122] A vehicle mode switching method provided in an embodiment of the present application can control the vehicle to automatically switch from series mode to power split mode by identifying the vehicle's operating condition information when the driver has the intention to reverse; at the same time, it is only necessary to adjust the torque of the engine 101 and then adjust the speed of the first motor, so that during the vehicle mode switching process, without opening the clutch 102 and keeping the first motor generating electricity, the shifting operations of the first synchronizer 105 and the second synchronizer 106 can be completed in sequence. In this way, the engine 101 can not only continue to drive the first motor to charge the power battery, but also enable the vehicle to switch more quickly and smoothly from the series mode to the power split mode in the reverse state, while meeting the charging needs of the power battery, effectively shortening the mode switching time, so that the engine 101 can quickly output torque and achieve rapid reversing, thereby effectively improving the vehicle's power response performance during the mode switching process.

[0123] For example, continuing to refer to Figure 1, the power splitting mechanism 104 may specifically include a ring gear 1041, a sun gear 1042, a plurality of planetary gears 1043 meshed between the ring gear 1041 and the sun gear 1042, and a planetary carrier 1044 rotatably connected to the plurality of planetary gears 1043; the planetary carrier 1044 is connected to the engine 101 as the first input end of the power splitting mechanism 104, the sun gear 1042 is connected to the first motor 103 as the second input end of the power splitting mechanism 104, the ring gear 1041 is connected to the gearbox input shaft 107 as the output end of the power splitting mechanism 104, and the first synchronizer 105 is arranged between the planetary carrier 1044 and the ring gear 1041.

[0124] In series mode, the first synchronizer 105 is in the engaged gear and the second synchronizer 106 is in neutral. At this point, the planetary carrier 1044 and the ring gear 1041 are locked. Since the second synchronizer 106 is in neutral, the driving force transmitted from the engine 101 to the planetary carrier 1044 via the clutch 102 is not transmitted to the transmission output shaft 108 via the first synchronizer 105, the ring gear 1041, or the transmission input shaft 107. Instead, it is transmitted to the first motor 103 via the plurality of planetary gears 1043 and the sun gear 1042 in sequence, driving the first motor 103 to generate electricity. The generated electricity is then supplied to the second motor to drive the vehicle.

[0125] In the power split mode, the first synchronizer 105 is in the power split gear. At this time, the planetary carrier 1044 and the ring gear 1041 are in the disconnected state. The driving force output by the engine 101 will be transmitted to the planetary carrier 1044 through the clutch 102, and the planetary carrier 1044 will transmit part of the driving force to the first motor 103 through multiple planetary gears 1043 and the sun gear 1042 in sequence to drive the first motor 103 to charge the power battery; at the same time, the planetary carrier 1044 will transmit another part of the driving force to the front axle of the vehicle through multiple planetary gears 1043, the ring gear 1041, the gearbox input shaft 107, the second synchronizer 106, the gearbox output shaft 108 and the front axle differential 109 in sequence to drive the vehicle to move.

[0126] Based on the above structure, the step of adjusting the torque of the engine 101 in S202 may specifically include the following sub-steps:

[0127] S202 - 1 : When the current gear position of the first synchronizer 105 is the engagement gear, the speed ratio between the sun gear 1042 and the planet carrier 1044 is determined to be the first speed ratio.

[0128] It should be noted that since the first synchronizer 105 has different gears, the planetary carrier 1044 and the ring gear 1041 have different speed ratios, and the sun gear 1042 has the same speed as the first motor 103, and the planetary carrier 1044 has the same speed as the engine 101. Therefore, based on the current gear of the first synchronizer 105, the speed ratio between the first motor 103 and the engine 101 can be determined.

[0129] In this embodiment, since the current gear position of the first synchronizer 105 is the engagement gear before the gear shift, the HCU determines that the speed ratio between the sun gear 1042 and the planet carrier 1044 is the first speed ratio.

[0130] S202 - 2 : Determine the target engine torque of the engine 101 based on the original motor torque of the first motor and the first speed ratio.

[0131] In this embodiment, since the rotational speed and the torque are in inverse proportion, the target engine torque of the engine 101 can be inversely calculated based on the first speed ratio and the current motor torque of the first motor 103 .

[0132] S202 - 3 : Based on a preset torque adjustment gradient, control the engine 101 to gradually reduce the original engine torque to the target engine torque.

[0133] In this embodiment, after determining the target engine torque, the HCU activates the torque control mode of the engine controller, so that the engine controller adjusts the current engine torque of the engine 101 to the target engine torque.

[0134] In a specific implementation, the current engine torque of the engine 101 can be controlled to follow the target engine torque according to a preset torque adjustment gradient, wherein the torque adjustment gradient represents the change in torque per unit time, for example, it can be set to 200 N·m / s.

[0135] In this embodiment, by adjusting the torque of the engine 101 according to the torque adjustment gradient, it is possible to avoid excessive torque changes that may affect the driving stability of the vehicle.

[0136] Exemplarily, the vehicle further includes a second motor, and the vehicle mode switching method may further include the following steps:

[0137] S301 : Determine a compensation torque of a second motor based on an original engine torque and an original motor torque.

[0138] In this embodiment, considering that the torque used to drive the front axle wheels will continue to decrease during the process of torque regulation of the engine 101, in order to ensure the power demand of the entire vehicle during the mode switching process, torque compensation will be performed through the second motor.

[0139] In this embodiment, since the original motor torque is negative torque and is used to offset a portion of the positive torque of the original engine torque, the HCU may determine the sum of the original engine torque and the original motor torque as the compensation torque of the second motor.

[0140] It should be noted that the original engine torque refers to the engine torque before the torque adjustment is performed on the engine 101 ; the original motor torque refers to the motor torque before the torque adjustment is performed on the engine 101 .

[0141] For example, before the torque of the engine 101 is adjusted, if the original engine torque is 800 N·m and the original motor torque is -300 N·m, the compensation torque of the second motor is 500 N·m.

[0142] S302 : Determine a target driving torque of the second motor based on the compensation torque and the original driving torque of the second motor.

[0143] In this embodiment, the HCU will further add a compensation torque to the original 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.

[0144] It should be noted that the original driving torque represents the torque output by the second motor before torque adjustment is performed on the engine 101 .

[0145] S303 : During the process of torque regulation of the engine 101 , the second motor is controlled to gradually increase the original driving torque to the target driving torque based on the torque regulation gradient.

[0146] In this embodiment, during the process of performing torque regulation on the engine 101 according to the torque regulation gradient, the HCU will also synchronously control the second motor to perform torque compensation according to the same torque regulation gradient.

[0147] In one example, the torque adjustment gradient is set to 200 N·m / s. If the HCU detects that the original engine torque output by the engine 101 is 800 N·m, the original motor torque output by the first motor 103 is -300 N·m, and the original drive torque output by the second motor is 400 N·m, then in response to the mode switch request, the HCU controls the engine 101 to gradually decrease from 800 N·m to 300 N·m according to the torque adjustment gradient of 200 N·m / s; while simultaneously controlling the second motor to gradually increase from 400 N·m to 900 N·m.

[0148] 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 jerking of the vehicle.

[0149] Exemplarily, the vehicle mode switching method may further include the following steps:

[0150] S401 : When the torque difference between the current engine torque of the engine 101 and the target engine torque is smaller than a torque threshold, timing of a first duration during which the torque difference is smaller than the torque threshold is triggered.

[0151] In this embodiment, while adjusting the torque of engine 101, the HCU obtains the current engine torque from the engine controller in real time. Upon detecting that the torque difference between the current engine torque and the target engine torque is less than a torque threshold, the HCU uses a timer to accumulate a first duration. Based on the first duration, the HCU determines whether the engine 101 is operating stably at the target engine torque. The first duration represents the duration of continuous and stable torque operation of the engine 101, and can be set to 50ms.

[0152] S402 : When the first duration is greater than a first duration threshold, determine that the second synchronizer 106 meets a first gear shift condition.

[0153] In this embodiment, if the HCU detects that the first duration is greater than the first duration threshold, it is considered that the engine 101 is stably running at the target engine torque, and further determines that the second synchronizer 106 meets the first gear shift condition.

[0154] In this embodiment, by monitoring the first duration, it is possible to effectively avoid controlling the second synchronizer 106 to perform a gear shift operation when abnormal torque fluctuation occurs in the engine 101, thereby ensuring that the second synchronizer 106 can shift gears smoothly.

[0155] In a feasible implementation, the step of adjusting the speed of the first motor 103 in S203 may specifically include the following sub-steps:

[0156] S203 - 1 : Determine a target motor speed of the first motor based on the current wheel speed of the target wheel, the current gear position of the first synchronizer 105 , and the target gear position of the second synchronizer 106 .

[0157] 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 wheel speed of the target wheel and the current gear of the first synchronizer 105 and the target gear of the second synchronizer 106.

[0158] 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.

[0159] In a specific implementation, S203-1 may include the following sub-steps:

[0160] S203 - 1 - 1 : When the current gear position of the first synchronizer 105 is the power split gear, determine that the speed ratio between the sun gear 1042 and the ring gear 1041 is the second speed ratio.

[0161] It should be noted that, since the current gear of the first synchronizer 105 is the power split gear, the planetary carrier 1044 and the ring gear 1041 are in a disengaged state. At this time, the speed between the engine 101 and the transmission input shaft 107 is decoupled. Therefore, while keeping the speed of the engine 101 unchanged, the speed of the transmission input shaft 107 can be adjusted by the first motor to make the second synchronizer 106 meet the second gear switching conditions.

[0162] It should be noted that different gears of the first synchronizer 105 correspond to different speed ratios. Specifically, when the current gear of the first synchronizer 105 is the power split gear, the speed ratio between the sun gear 1042 and the ring gear 1041 is the second speed ratio.

[0163] S203-1-2: When the target gear position of the second synchronizer 106 is the reverse gear, the speed ratio between the transmission input shaft 107 and the target wheel is determined to be the third speed ratio.

[0164] In this embodiment, different gear positions of the second synchronizer 106 correspond to different speed ratios. When the target gear position of the second synchronizer 106 is reverse, the speed ratio between the transmission input shaft 107 and the target wheel is the target speed ratio. This target speed ratio represents the speed ratio between the transmission input shaft 107 and the transmission output shaft 108. Therefore, based on the target speed ratio and in combination with 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.

[0165] S203-1-3: Determine a fourth speed ratio between the target wheel and the first motor based on the second speed ratio and the third speed ratio.

[0166] In this embodiment, based on the second speed ratio, the speed ratio between the sun gear 1042 and the ring gear 1041 can be calculated. Since the rotational speeds of the first motor 103 and the sun gear 1042 are the same, and the rotational speeds of the ring gear 1041 and the transmission input shaft 107 are the same, the fourth speed ratio between the first motor 103 and the target wheel can be calculated by further combining the third speed ratio.

[0167] In a specific implementation, the fourth speed ratio between the first motor 103 and the target wheel can be calculated according to the following formula: i3 = i1 × i2 (1);

[0168] Among them, i3 represents the fourth speed ratio between the first motor 103 and the target wheel, i1 represents the second speed ratio between the sun gear 1042 and the ring gear 1041, and i2 represents the third speed ratio between the transmission input shaft 107 and the target wheel.

[0169] S203-1-4: Determine the target motor speed of the first motor based on the fourth speed ratio and the current wheel speed of the target wheel.

[0170] In a specific implementation, the target motor speed of the first motor 103 can be calculated according to the following formula: n=n0×i3(2);

[0171] Wherein, n represents the target motor speed of the first motor 103 , n0 represents the current wheel speed of the target wheel, and i3 represents the fourth speed ratio between the first motor 103 and the target wheel.

[0172] S203 - 2 : Control the current motor speed of the first motor to follow the target motor speed.

[0173] 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.

[0174] 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.

[0175] 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.

[0176] 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.

[0177] 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.

[0178] Exemplarily, the vehicle mode switching method may further include the following steps:

[0179] S501 : When the current motor speed of the first motor reaches the target motor speed, trigger timing of a second duration for which the fluctuation amplitude of the current motor speed is less than a speed threshold.

[0180] 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.

[0181] In a specific implementation, the HCU will trigger the timing of the second duration after first detecting that the current motor speed reaches the target motor speed. The second duration represents the duration of continuous and stable operation of the first motor 103 in terms of speed, and can be specifically set to 50ms.

[0182] S502 : When the second duration is greater than a second duration threshold, determine that the second synchronizer 106 meets a second gear shifting condition.

[0183] In this embodiment, when the second duration is greater than the second 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.

[0184] 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.

[0185] 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, and a gearbox; the gearbox includes a power split mechanism 104 , a gearbox input shaft 107 , a gearbox output shaft 108 , a first synchronizer 105 , and a second synchronizer 106 ; the engine 101 is connected to a first input end of the power split mechanism 104 via the clutch 102 , the first motor 103 is connected to a second input end of the power split mechanism 104 , the output end of the power split mechanism 104 is connected to the gearbox input shaft 107 , the 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:

[0186] a condition determination module 301 for determining, based on the vehicle's operating condition information, whether the vehicle satisfies a mode switching condition for switching from the series mode to the power split mode when it is determined that the driver has a reverse intention;

[0187] The torque adjustment module 302 is configured to, upon determining that the vehicle satisfies the mode switching condition, maintain the clutch 102 in a closed state, the first motor in a generating state, and adjust the torque of the engine 101 so that the first synchronizer 105 satisfies the first gear switching condition;

[0188] The speed regulating module 303 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 switching condition; and to regulate the speed of the first motor so that the second synchronizer 106 satisfies the second gear switching condition;

[0189] The mode switching module 304 is configured to control the second synchronizer 106 to switch from the current gear to the reverse gear when the second synchronizer 106 satisfies the second gear switching condition, so as to switch the vehicle from the series mode to the power split mode.

[0190] In one embodiment of the present application, the operating condition information includes the current driving mode, the current road condition, and the current remaining power of the power battery; the condition determination module 301 includes:

[0191] The switching condition determination submodule is used to determine whether the vehicle meets the mode switching conditions for switching from the series mode to the power split mode when the current driving mode is the series mode, the current road condition is the preset road condition, and the current remaining power is less than the power threshold.

[0192] In one embodiment of the present application, the power split mechanism 104 includes a ring gear 1041, a sun gear 1042, a plurality of planetary gears 1043 meshed between the ring gear 1041 and the sun gear 1042, and a planetary carrier 1044 rotatably connected to the plurality of planetary gears 1043; the planetary carrier 1044 is connected to the engine 101 as a first input end, the sun gear 1042 is connected to the first motor as a second input end, the ring gear 1041 is connected to the transmission input shaft 107 as an output end, and the first synchronizer 105 is disposed between the planetary carrier 1044 and the ring gear 1041; the torque adjustment module 302 includes:

[0193] A speed ratio determination submodule, configured to determine that the speed ratio between the sun gear 1042 and the planet carrier 1044 is the first speed ratio when the current gear position of the first synchronizer 105 is the engagement gear;

[0194] an engine torque determination submodule, configured to determine a target engine torque of the engine 101 based on the original motor torque of the first motor and the first gear ratio;

[0195] The engine torque control submodule is configured to control the engine 101 to gradually reduce the original engine torque to the target engine torque based on a preset torque adjustment gradient.

[0196] In one embodiment of the present application, the vehicle mode switching device 300 further includes:

[0197] a compensation torque determination module, configured to determine a compensation torque for the second motor based on the original engine torque and the original motor torque;

[0198] a driving torque determination module for determining a target driving torque of the second motor based on the compensation torque and the original driving torque of the second motor;

[0199] The driving torque control module is configured to control the second motor to gradually increase the original driving torque to the target driving torque based on the torque adjustment gradient during the process of adjusting the torque of the engine 101 .

[0200] In one embodiment of the present application, the vehicle mode switching device 300 further includes:

[0201] a timing module, configured to trigger timing of a first duration of time during which the torque difference is less than the torque threshold when the torque difference between the current engine torque of the engine 101 and the target engine torque is less than the torque threshold;

[0202] The first condition determination module is configured to determine that the first synchronizer 105 meets a first gear shift condition when the first duration is greater than a first duration threshold.

[0203] In one embodiment of the present application, the speed adjustment module 300 includes:

[0204] a motor speed determination submodule, configured to determine a target motor speed of the first motor based on a current wheel speed of the target wheel and a current gear position of the first synchronizer 105 and a target gear position of the second synchronizer 106;

[0205] The motor speed control submodule is used to control the current motor speed of the first motor to follow the target motor speed.

[0206] In one embodiment of the present application, the motor speed determination submodule includes:

[0207] 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 sun gear 1042 and the ring gear 1041 is the second speed ratio;

[0208] a second speed ratio determining unit, configured to determine, when the target gear position of the second synchronizer 106 is the reverse gear, that the speed ratio between the transmission input shaft 107 and the target wheel is a third speed ratio;

[0209] 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 and the third speed ratio;

[0210] 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.

[0211] In one embodiment of the present application, the vehicle mode switching device 300 further includes:

[0212] a second timing module, configured to trigger timing of a second duration for which a fluctuation amplitude of the current motor speed is less than a speed threshold when the current motor speed of the first motor reaches a target motor speed;

[0213] The second condition determination module is configured to determine that the second synchronizer 106 satisfies a second gear shift condition when the second duration is greater than a second duration threshold.

[0214] 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.

[0215] In 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 and a gearbox; the gearbox includes a power splitting mechanism 104 , a gearbox input shaft 107 , a gearbox output shaft 108 , a first synchronizer 105 and a second synchronizer 106 , the engine 101 is connected to the first input end of the power splitting mechanism 104 through the clutch 102 , the first motor 103 is connected to the second input end of the power splitting mechanism 104 , the output end of the power splitting mechanism 104 is connected to the gearbox input shaft 107 , the second synchronizer 106 is arranged between the gearbox input shaft 107 and the gearbox output shaft 108 , and the first synchronizer 105 is arranged between the first input end and the output end; the system includes a vehicle controller 401 , a gearbox controller 402 , a motor controller 403 and an engine controller 404 ; wherein,

[0216] The vehicle controller 401 is configured to, upon determining that the driver intends to reverse, determine whether the vehicle satisfies a mode switching condition for switching from the series mode to the power split mode based on the vehicle's operating condition information; and, upon determining that the vehicle satisfies the mode switching condition, send an engine torque adjustment request to the engine controller 404, send a clutch state maintenance request to the transmission controller 402, and send a motor state maintenance request to the motor controller 403;

[0217] The transmission controller 402 is used to keep the clutch 102 in a closed state in response to the clutch state keeping request; the motor controller 403 is used to keep the first motor in a generating state in response to the motor state keeping request;

[0218] The engine controller 404 is configured to adjust the torque of the engine 101 in response to the engine torque adjustment request so that the first synchronizer 105 satisfies the first gear shift condition;

[0219] The vehicle controller 401 is further configured to send a first gear shift request to the transmission controller 402 and a motor speed adjustment request to the motor controller 403 when the first synchronizer 105 satisfies the first gear shift condition;

[0220] The transmission controller 402 is further configured to control the first synchronizer 105 to switch from the engagement gear to the power split gear in response to the first gear shift request; the motor controller 403 is further configured to adjust the speed of the first motor in response to the motor speed adjustment request so that the second synchronizer 106 meets the second gear shift condition;

[0221] The vehicle controller 401 is further configured to send a second gear shift request to the transmission controller 402 when the second synchronizer 106 satisfies the second gear shift condition;

[0222] The transmission controller 402 is further configured to control the second synchronizer 106 to shift from the current gear to the reverse gear in response to the second gear shift request, so as to switch the vehicle from the series mode to the power split mode.

[0223] 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.

[0224] 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.

[0225] 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.

[0226] 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.

[0227] 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.

[0228] 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.

[0229] 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 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 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 method includes: When it is determined that the driver has a reverse intention, based on the operating condition information of the vehicle, determine whether the vehicle meets the mode switching condition for switching from the series mode to the power split mode; When it is determined that the vehicle meets the mode switching condition, keep the clutch in a closed state, keep the first motor in a power generation state, and adjust the torque of the engine so that the first synchronizer meets the first gear switching condition; When the first synchronizer meets the first gear switching condition, control the first synchronizer to switch from the engaged gear to the power split gear; and adjust the speed of the first motor so that the second synchronizer meets the second gear switching condition; When the second synchronizer meets the second gear switching condition, control the second synchronizer to switch from the current gear to the reverse 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 operating condition information includes the current driving mode, the current road condition, and the current remaining power of the power battery; The step of determining whether the vehicle meets the mode switching condition for switching from the series mode to the power split mode based on the operating condition information of the vehicle includes: When the current driving mode is the series mode, the current road condition is a preset road condition, and the current remaining power is less than the power threshold, determine that the vehicle meets the mode switching condition for switching from the series mode to the power split mode.

3. The vehicle mode switching method according to claim 1, characterized in that The power split mechanism includes a ring gear, a sun gear, a plurality of planet gears meshing between the ring gear and the sun gear, and a planet carrier rotatably connected to the plurality of planet gears; the planet carrier is connected to the engine as the first input end, the sun gear is connected to the first motor as the second input end, the ring gear is connected to the transmission input shaft as the output end, and the first synchronizer is arranged between the planet carrier and the ring gear; The step of adjusting the torque of the engine includes: When the current gear of the first synchronizer is the engaged gear, determine that the transmission ratio between the sun gear and the planet carrier is the first transmission ratio; Based on the original motor torque of the first motor and the first transmission ratio, determine the target engine torque of the engine; Based on a preset torque adjustment gradient, control the engine to gradually decrease from the original engine torque to the target engine torque.

4. The vehicle mode switching method according to claim 3, wherein, The vehicle further includes a second motor, and the method further includes: Determine the compensation torque of the second motor based on the original engine torque and the original motor torque; Determine the target drive torque of the second motor based on the compensation torque and the original drive torque of the second motor; During the process of torque adjustment of the engine, control the second motor to gradually increase from the original drive torque to the target drive torque based on the torque adjustment gradient.

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

6. The vehicle mode switching method according to claim 3, wherein, The step of adjusting the speed of the first motor includes: Determine the target motor speed of the first motor based on the current wheel speed of the target wheel, the current gear position of the first synchronizer, and the target gear position of the second synchronizer; Control the current motor speed of the first motor to follow the target motor speed.

7. The vehicle mode switching method according to claim 6, wherein, The step of determining the target motor speed of the first motor based on the current wheel speed of the target wheel, 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, determine that the speed ratio between the sun gear and the ring gear is the second speed ratio; When the target gear position of the second synchronizer is the reverse gear position, determine that the speed ratio between the transmission input shaft and the target wheel is the third speed ratio; Determine the fourth speed ratio between the target wheel and the first motor based on the second speed ratio and the third speed ratio; Determine the target motor speed of the first motor based on the fourth speed ratio and the current wheel speed of the target wheel.

8. The vehicle mode switching method according to claim 6, wherein The method further includes: When the current motor speed of the first motor reaches the target motor speed, trigger the timing of the second duration for which the fluctuation amplitude of the current motor speed is less than the speed threshold; When the second duration is greater than the second duration threshold, determine that the second synchronizer meets the second gear shifting condition.

9. 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 vehicle mode switching device includes: A condition determination module, configured to determine whether the vehicle meets the mode switching condition for switching from the series mode to the power split mode based on the working condition information of the vehicle when it is determined that the driver has a reverse intention; The torque adjustment module is used to keep the clutch in a closed state and the first motor in a power generation state when it is determined that the vehicle meets the mode switching condition, and adjust the torque of the engine to make the first synchronizer meet the first gear shifting condition; The speed adjustment module is used to control the first synchronizer to switch from the engaged gear to the power split gear when the first synchronizer meets the first gear shifting condition; and adjust the speed of the first motor to make the second synchronizer meet the second gear shifting condition; The mode switching module is used to control the second synchronizer to switch from the current gear to the reverse 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.

10. 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 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 system includes a vehicle controller, a transmission controller, a motor controller and an engine controller; wherein, The vehicle controller is used to determine whether the vehicle meets the mode switching condition from the series mode to the power split mode based on the working condition information of the vehicle when it is determined that the driver has a reverse intention; and when it is determined that the vehicle meets the mode switching condition, send an engine torque adjustment request to the engine controller, send a clutch state holding request to the transmission controller, and send a motor state holding request to the motor controller; The transmission controller is used to keep the clutch in a closed state in response to the clutch state holding request; the motor controller is used to keep the first motor in a power generation state in response to the motor state holding request; The engine controller is used to adjust the torque of the engine in response to the engine torque adjustment request to make the first synchronizer meet the first gear shifting condition; The vehicle controller is further used to send a first gear shifting request to the transmission controller and send a motor speed adjustment request to the motor controller when the first synchronizer meets the first gear shifting condition; The transmission controller is further used to control the first synchronizer to switch from the engaged gear to the power split gear in response to the first gear shifting request; the motor controller is further used to adjust the speed of the first motor in response to the motor speed adjustment request to make the second synchronizer meet the second gear shifting condition; The vehicle controller is further configured to send a second shift request to the transmission controller when the second synchronizer meets the second gear shifting condition; The transmission controller is further configured to control the second synchronizer to shift from the current gear to the reverse gear in response to the second shift request, so as to switch the vehicle from the series mode to the power split mode.

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

12. 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 1-8.

13. A computer-readable medium, characterized in that, Wherein a computer program according to claim 12 is stored.

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