Vehicle control method and vehicle

Abstract

The application provides a vehicle control method and a vehicle, and relates to the technical field of vehicle control. The method acquires transmission system state information and running state information of a vehicle in response to a current accelerator pedal opening being greater than a preset opening threshold value, determines a current power transmission working mode and an available power transmission working mode according to the transmission system state information, so as to identify the current power transmission working mode and select the available power transmission working mode; and according to the running state information, determines a target power transmission working mode that can provide driving force greater than that provided by the current power transmission working mode from the available power transmission working modes, and switches the current power transmission working mode to the target power transmission working mode, thereby solving the technical problem of driving force attenuation caused by forced switching of a series mode.

Description

Technical Field

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

[0002] When a four-wheel drive hybrid vehicle is in pure electric driving mode and a high torque demand from the driver is detected, the conventional control logic prioritizes starting the engine to switch to the direct drive mode with optimal power performance. If a direct drive-related component malfunctions and prevents the direct drive mode from being activated, the existing strategy will directly start the engine to switch to the series drive mode. However, the series drive mode only relies on the rear axle motor to output torque, which has a lower power limit compared to the pure electric four-wheel drive mode that can output combined front and rear axle drive force. This makes it unable to match the driver's high torque demand and results in insufficient power output. Summary of the Invention

[0003] In view of this, the purpose of this application is to propose a vehicle control method and a vehicle to improve the power performance and driving reliability of hybrid four-wheel drive vehicles under fault conditions and high torque conditions.

[0004] To achieve the above objectives, this application provides a vehicle control method, the method comprising:

[0005] In response to the current accelerator pedal opening being greater than a preset opening threshold, the system acquires the vehicle's transmission system status information and operating status information. Based on the transmission system status information, determine the current power transmission operating mode and the available power transmission operating modes; Based on the operating status information, among the available power transmission operating modes, a target power transmission operating mode that can provide the vehicle with a driving force greater than that provided by the current power transmission operating mode is determined. Switch the current power transmission operating mode to the target power transmission operating mode.

[0006] Specifically, in response to the current accelerator pedal opening exceeding a preset threshold, the system acquires the vehicle's transmission system status and operating status information to identify the driver's high torque demand. Vehicle-related status information is only collected when a high driving force request is detected, avoiding meaningless data collection and reducing controller computational overhead. Based on the transmission system status information, the current powertrain operating mode and available powertrain operating modes are determined. Based on the actual hardware status and fault conditions of the transmission system, the system identifies the vehicle's current actual powertrain operating mode and eliminates unusable modes due to hardware faults, resulting in a set of compliant and usable modes to prevent issuing invalid control commands to faulty hardware. Based on the operating status information, among the available powertrain operating modes, a target powertrain operating mode that can provide the vehicle with a driving force greater than that provided by the current powertrain operating mode is determined. This target powertrain operating mode with a driving force greater than the current powertrain operating mode is selected by combining the vehicle's operating status, balancing the driver's driving force demand with the vehicle's actual operating constraints, ensuring that the driving force output matches the driver's operating intentions as closely as possible. The current powertrain operating mode is switched to the target powertrain operating mode. This mode switching action completes the transition from the current powertrain operating mode to the target powertrain operating mode, allowing the vehicle to operate according to the driving force provided by the target powertrain operating mode. This matches the driver's driving force requirements and responds to the driver's power requests. This solves the technical problem of power attenuation caused by forced switching to series mode in existing solutions under high throttle conditions, balancing the driver's power needs with the actual operating constraints of the vehicle, ensuring that the power output matches the driver's operating intentions.

[0007] Based on the same inventive concept, this application also provides a vehicle, the vehicle comprising: Memory, used to store executable program code; A processor is configured to call and run the executable program code from the memory, causing the vehicle to perform the method as described in any of the preceding claims. Attached Figure Description To more clearly illustrate the technical solutions in this application or related technologies, the drawings used in the description of the embodiments or related technologies will be briefly introduced below. Obviously, the drawings described below are only embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0008] Figure 1 This is a schematic diagram of the direct drive mode driving principle structure according to an embodiment of this application; Figure 2 This is a schematic diagram of the serial mode driving principle structure according to an embodiment of this application; Figure 3This is a schematic diagram of the pure electric four-wheel drive mode driving principle structure according to an embodiment of this application; Figure 4 This is a schematic diagram of the pure electric two-wheel drive mode driving principle structure according to an embodiment of this application; Figure 5 This is a schematic flowchart of a vehicle control method according to an embodiment of this application; Figure 6 This is a schematic diagram of the structural framework of a vehicle control device according to an embodiment of this application; Figure 7 This is a schematic diagram of the hardware structure of an electronic device according to an embodiment of this application. Detailed Implementation

[0009] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with specific embodiments and the accompanying drawings.

[0010] It should be noted that, unless otherwise defined, the technical or scientific terms used in the embodiments of this application should have the ordinary meaning understood by one of ordinary skill in the art to which this application pertains. The terms "first," "second," and similar terms used in the embodiments of this application do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are only used to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0011] In this article, it is important to understand that any number of elements in the accompanying figures is for illustrative purposes and not for limitation, and any naming is for distinction only and has no limiting meaning.

[0012] Based on the above background description, the following situations also exist in the related technologies: Current four-wheel drive hybrid vehicles possess multiple power transmission modes, including pure electric two-wheel drive, pure electric four-wheel drive, series drive, and engine direct drive (hereinafter referred to as direct drive mode). The overall vehicle power output capability varies significantly between these modes, with the power output capability from highest to lowest being: engine direct drive mode, pure electric four-wheel drive mode, pure electric two-wheel drive mode, and series drive mode. The series drive mode and pure electric two-wheel drive mode rely solely on the rear axle motor to output drive torque, and their maximum power output is the same. It should be noted that this power refers to the wheel-end driving force of the vehicle.

[0013] like Figure 1 The diagram illustrates the direct-drive mode. In this mode, clutch K1 or clutch K2 is engaged, and the synchronizers on the odd-numbered or even-numbered shafts are engaged in the corresponding G1 / G3 or G2 / G4 gears. Engine power is directly transmitted to the front wheels via the clutch and gearbox gears. The rear axle motor synchronously outputs drive torque. The front motor can provide power assist or generate electricity depending on the operating conditions. The entire vehicle is driven by the engine, front motor, and rear motor, corresponding to the arrows in the diagram that indicate the power output from the front engine, front motor, and rear axle motor to the front and rear wheels, respectively. This is the mode with the strongest power output among the four modes, suitable for high-speed, high-torque scenarios. For an example, please refer to the following for details. Figure 1 In engine direct drive mode, you can select to engage clutch K1 and shift the odd-numbered gearbox shafts to G1 or G3, or engage clutch K2 and shift the even-numbered gearbox shafts to G2 or G4. Engine power is transmitted to the gearbox shafts via the corresponding engaged clutches, and mechanical drive force is output to the front wheels via the gear mechanism. The rear axle motor can participate in driving the rear wheels according to the working conditions, realizing a transmission path where the front wheels are directly driven by the engine and the rear wheels are assisted by the motor. In this mode, the front motor can rotate with the corresponding gear shaft, and can act as a motor to output assist torque or as a generator to generate electricity. The attached diagram only shows the basic mechanical connection relationship. Both of the above motor working states can be realized on this hardware path.

[0014] Figure 2 The diagram illustrates a series drive mode. In this mode, clutch K2 is engaged, the synchronizers on even-numbered shafts are in neutral, and the synchronizers on odd-numbered shafts are also in neutral, resulting in a neutral front axle. The engine drives the front motor to generate electricity solely through the engaged clutch K2. Electrical energy is then supplied to the battery and the rear axle motor. The front axle receives no mechanical power output; the rear wheels are driven solely by the rear motor. This corresponds to the power flow characteristic shown in the diagram, where the engine power is directed only to the front motor, and only the rear axle drives the wheels. The overall vehicle driving capability is equivalent to a pure electric two-wheel drive mode. For an example, please refer to [link / reference]. Figure 2 In this mode, the engine stops, K1 and clutch K2 gears are all disengaged, the synchronizers of odd and even shafts are in neutral, the front motor has no power output, the power battery only supplies power to the rear axle rear motor, and the rear motor drives the rear wheels alone. This corresponds to the structural characteristics in the diagram where only the rear axle has the power arrows for driving the wheels and the front axle has no power output line. This is the basic pure electric operating condition under low load and low torque requirements.

[0015] Figure 3The diagram illustrates the pure electric four-wheel drive mode. In this mode, the engine remains off, and gears K1 and clutch K2 are fully disengaged. The even-numbered shaft synchronizer is engaged in gears G2 / G4. The battery simultaneously supplies power to both the front and rear motors. The front motor drives the front wheels via the even-numbered shaft gearbox, and the rear motor drives the rear wheels via the rear axle reduction gearbox. Power arrows pointing to the wheels are present on both the front and rear axles in the diagram. This four-wheel drive is achieved through the combined power of the front and rear motors, resulting in a higher maximum driving force than the series and pure electric two-wheel drive modes. See details below. Figure 3 In pure electric four-wheel drive mode, the engine stops, and both K1 and clutch K2 gears are disengaged, completely decoupling the engine from the transmission. The even-numbered shaft of the transmission is engaged in G2 or G4 gear, and the power battery simultaneously supplies power to the front motor and the rear motor. The front motor drives the front wheels through the even-numbered shaft gear, and the rear motor drives the rear wheels, realizing four-wheel drive between the front and rear wheels. In some fault scenarios, if the even-numbered shaft path is unavailable, this pure electric four-wheel drive mode cannot be established, and it can only be switched to pure electric two-wheel drive mode.

[0016] Figure 4 The diagram shows a pure electric two-wheel drive mode. In this mode, the engine is off, clutches K1 and K2 are fully disengaged, the synchronizers on odd and even shafts are in neutral, the front motor has no power output, and the power battery only supplies power to the rear axle motor. The rear motor drives the rear wheels independently. This corresponds to the structural features in the diagram where only the rear axle has the power arrows for driving the wheels and the front axle has no power output circuit. This is the basic pure electric operating condition under low load and low torque requirements.

[0017] Specific reference Figure 4 In two-wheel drive mode, the engine stops, clutches K1 and K2 are disengaged, and both odd and even shafts of the transmission are in neutral. There is no mechanical power output from the front axle, and the power battery only supplies power to the rear motor of the rear axle, which drives the rear wheels independently. This mode is the basic rear-wheel drive pure electric condition and is not constrained by conditions other than failure of the front transmission or front motor circuit. The attached diagram only shows the power flow of the rear-wheel drive.

[0018] The existing vehicle control logic does not perform start-stop source correction and optimization for fault scenarios such as abnormalities in direct drive path components and inability to activate direct drive mode. If the system detects that direct drive mode is unavailable, it will directly trigger engine start and switch to series drive mode. The power output capability of series drive mode is much lower than that of pure electric four-wheel drive mode, which cannot match the driver's high torque demand, resulting in a decrease in the actual power output of the vehicle and a large discrepancy between the driving experience and the driver's torque expectation. At the same time, the existing control logic does not coordinate the differentiating mode switching control based on multiple dimensions such as the remaining battery charge, the fault status of the series path, and the current operating transmission mode. Under fault conditions, the engine start-stop and power mode switching logic is simplistic, making it difficult to balance the power performance and the energy maintenance needs of the power battery, resulting in poor adaptability of the vehicle under operating conditions.

[0019] To solve the above technical problems, such as Figure 5 As shown, this application provides a vehicle control method, including the following steps: Step 102: In response to the current accelerator pedal opening being greater than the preset opening threshold, obtain the vehicle's transmission system status information and operating status information.

[0020] In this step, the accelerator pedal position sensor collects the analog signal of the pedal travel in real time. The sensor converts the opening into a voltage signal and transmits it to the Vehicle Control Unit (VCU). The analog-to-digital converter module inside the VCU converts the analog voltage into a standardized opening percentage (0%~100%), enabling real-time reading of the opening value. The preset opening threshold can be calibrated by looking up a table based on vehicle speed, vehicle load, and gradient. For example, the preset opening threshold is calibrated to 30% for flat roads and low-to-medium speed (0~60km / h) scenarios; when the driver presses the accelerator to 30% or more, a high torque demand is determined. For high-speed conditions (>90km / h), the preset opening threshold is calibrated to 40%; at high speeds, a pedal opening exceeding 40% triggers the determination of a high torque demand. For heavy-load scenarios on slopes, the preset opening threshold is lowered to 20%, and a small, deeper press of the accelerator is sufficient to identify high torque requests for overtaking and climbing. In other words, the preset opening threshold in this application can be determined based on the vehicle's driving conditions. When the accelerator pedal opening exceeds the preset threshold for the corresponding operating condition, it is determined that the driver has a high torque driving demand, and two types of vehicle information are collected simultaneously. Specifically, the clutch travel position sensor and clutch temperature sensor, in conjunction with the transmission control unit (TCU), collect the fault status of clutch K1 and clutch K2 gears and the clutch disengagement / engagement status. The synchronizer position displacement sensor, in conjunction with the TCU, collects the transmission fault status, all gear damage status, the position of the odd-numbered shaft synchronizer, and the position of the even-numbered shaft synchronizer. The front motor rotary transformer and front motor controller (MCU) collect the front motor fault status, front motor start / stop status, and front motor drive or generator operation status. The rear motor rotary transformer and rear axle motor controller (MCU) collect the rear motor fault status, rear motor start / stop, and torque output status. All the above sensor data are integrated to form the vehicle's transmission system status information, used to determine the hardware integrity and actual position of the mechanical mechanisms in each power transmission path. The battery management system (BMS) collects the real-time remaining power of the power battery. This remaining power data constitutes the vehicle operating status information required by this application, used to constrain the power mode selection logic under different power ranges. This step uses the driver's acceleration intention as the strategy trigger entry point, and fully collects core parameters such as transmission hardware faults, gear positions, and remaining battery power. This provides complete and accurate underlying data support for subsequent power mode recognition and available mode selection. It can accurately distinguish between normal driving and high torque conditions such as overtaking and climbing, avoiding meaningless and frequent calculations in the control logic. It can also help to understand the fault status of transmission components and the upper limit of battery energy supply in advance, preventing subsequent mode switching failures and power battery depletion issues.

[0021] Step 104: Determine the current power transmission working mode and available power transmission working modes based on the transmission system status information.

[0022] In this step, based on the above embodiments, when the accelerator pedal opening exceeds the preset opening threshold for the corresponding operating condition, it is determined that the driver has a high torque driving demand, and then two types of vehicle information are collected simultaneously. Among them, the clutch travel position sensor and clutch temperature sensor, together with the transmission controller TCU, collect the fault status of K1 and clutch K2 gears and the clutch disengagement / engagement working status; the synchronizer position displacement sensor, together with the TCU, collects the transmission fault status, the damage status of all gears, the position of the odd-numbered shaft synchronizer, and the position of the even-numbered shaft synchronizer; the front motor rotary transformer and the front motor controller MCU collect the front motor fault status, the front motor start / stop status, and the front motor drive or generator working status; the rear motor rotary transformer and the rear axle motor controller MCU collect the rear motor fault status, the rear motor start / stop and torque output status. All the above sensor data are integrated to form the vehicle's transmission system status information, which is used to determine the hardware integrity and actual position of the mechanical mechanism of each power transmission path; the battery management system BMS collects the real-time remaining power of the power battery, and this remaining power data constitutes the vehicle operating status information required by this application, which is used to constrain the power mode selection logic under different power ranges. This step uses the driver's acceleration intention as the strategy trigger entry point, and fully collects core parameters such as transmission hardware faults, gear positions, and remaining battery power. This provides complete and accurate underlying data support for subsequent power mode recognition and available mode selection. It can accurately distinguish between normal driving and high torque conditions such as overtaking and climbing, avoiding meaningless and frequent calculations in the control logic. It can also help to understand the fault status of transmission components and the upper limit of battery energy supply in advance, preventing subsequent mode switching failures and power battery depletion issues.

[0023] Specifically, the transmission system status information includes: clutch working status, gearbox gear position status, front motor status, front motor drive status, front motor working status, rear motor status, even-numbered shaft synchronizer position, and odd-numbered shaft synchronizer position. It should be noted that, in combination Figure 1-4As shown, the clutch operating status represents the physical engagement / disengagement of clutches K1 and K2, categorized into three states: fully disengaged, odd-numbered gears engaged (K1 only), and even-numbered gears engaged (K2 only). This status is used to determine whether a mechanical transmission link has been established between the engine and the odd-numbered and even-numbered shafts. The gearbox gear status includes overall gearbox fault signals and hardware damage indicators for each gear, assisting in determining whether the corresponding gear path can establish normal power transmission. The front motor status is divided into two indicators: stopped and started, distinguishing whether the front motor has completed power-on operation. The front motor drive status includes two categories: electric drive and engine drive mode. Electric drive mode indicates that the power battery powers the front motor to output power, while engine drive mode indicates that the engine drives the front motor to rotate via the clutch. The front motor operating status includes output torque and generator mode. Output torque mode corresponds to the front motor outputting drive torque, while generator mode corresponds to the front motor absorbing mechanical energy and converting it into electrical energy. The rear motor status is divided into two indicators: stopped and started, representing whether the rear axle drive motor is in an operating state capable of outputting torque. Even-numbered shaft synchronizer positions: divided into neutral position and even-numbered gear (G2 / G4), determining the mechanical connection between the even-numbered shaft and the front wheel differential. Odd-numbered shaft synchronizer positions: divided into neutral position and odd-numbered gear (G1 / G3), determining the mechanical connection between the odd-numbered shaft and the front wheel differential.

[0024] Determining the current power transmission operating mode based on the transmission system status information includes the following steps: Step 104-11: In response to the engine being in a stopped state, the clutch being in a fully disengaged state, the front motor being in a stopped state, and the rear motor being in a started state, determine that the current power transmission working mode is a pure electric two-wheel drive mode.

[0025] In this step, such as Figure 4As shown, when the engine is stopped, the clutch is fully disengaged, the front motor is stopped, and the rear motor is running (i.e., the engine is stopped, both K1 and K2 gears of the clutch are fully disengaged, the front motor is stopped, and the rear motor is running), the transmission system status information is as described above. The current power transmission mode is pure electric two-wheel drive. The operating logic of pure electric two-wheel drive is as follows: the engine is completely off, both clutches are fully disengaged, and the engine is completely decoupled from the front gearbox; the front motor is not powered and has no power output; the synchronizers of the odd and even shafts are in neutral, and there is no driving torque on the front axle; only the rear axle motor is powered and operates, relying solely on the rear motor to drive the rear wheels, which is the principle of pure electric two-wheel drive. For example, suitable driving conditions for this mode include: smooth low-speed cruising in the city, sufficient battery charge, and the driver using a light throttle. The vehicle operates in this pure electric two-wheel drive mode under these conditions.

[0026] In this embodiment, the engine is completely shut off, clutches K1 and K2 are fully disengaged, and the engine is completely decoupled from the front transmission. The front motor is not powered on and is off, and the synchronizers of both odd and even shafts are in neutral, resulting in no drive torque output from the front axle. Only the rear motor of the rear axle is powered on and operates independently, driving the rear wheels. This is suitable for low-speed, stable driving conditions in urban areas with low torque requirements. Thus, relying solely on the characteristic combination of complete disengagement of the front transmission components and operation of only the rear motor, the basic rear-wheel-drive pure electric driving condition can be accurately identified. The judgment conditions are simple, and the controller's calculation time is short. It can accurately distinguish low-load driving states without the participation of the front motor, providing accurate operating condition data for maintaining two-wheel-drive driving in subsequent low-battery and low-power demand scenarios, avoiding unnecessary engine starts and four-wheel-drive intervention, and saving energy.

[0027] Step 104-12: In response to the engine being in a stopped state, the clutch being in a fully disengaged state, the even-numbered shaft synchronizer being in an even-numbered gear position, the front motor being in an electric drive state, the front motor being in an output torque state, and the rear motor being in a start state, determine that the current power transmission working mode is a pure electric four-wheel drive mode.

[0028] In this step, such as Figure 3As shown, when the engine is stopped, the clutch is fully disengaged, the even-numbered shaft synchronizer is in an even-numbered gear position, the front motor is in electric drive mode, the front motor is in output mode, and the rear motor is in start mode, i.e., the engine is stopped, the clutches in K1 (odd-numbered gear) and K2 (even-numbered gear) are fully disengaged, the even-numbered shaft synchronizer is engaged in G2 or G4 even-numbered gear, the front motor is in electric drive mode and output torque mode, and the rear motor is in start mode, and the transmission system status information is as described above, the current power transmission mode is pure electric four-wheel drive mode. The operating logic of pure electric four-wheel drive mode is as follows: the engine remains off, the clutch is fully disengaged, and the engine does not participate in transmission; the even-numbered shaft synchronizer is engaged in an even-numbered gear, the power battery simultaneously supplies power to the front motor and the rear motor, the front motor outputs drive torque to the front wheels through the even-numbered shaft, and the rear motor outputs drive torque to the rear wheels, realizing the combined four-wheel drive of the front and rear wheels by the front and rear motors. The pure electric four-wheel drive mode is applicable to the following conditions: when the driver presses the accelerator hard, when the road surface is slippery and requires stronger grip, or when climbing hills and requires high torque, the vehicle switches to this pure electric four-wheel drive mode.

[0029] In this embodiment, the engine remains off, clutches K1 and K2 are fully disengaged, and the engine does not engage in transmission. The even-numbered shaft synchronizer is engaged in G2 / G4 gear, and the power battery simultaneously supplies power to the front and rear motors. The front motor outputs drive torque to the wheels via the even-numbered shaft, and the rear motor synchronously drives the rear wheels, achieving four-wheel joint drive. This is suitable for conditions requiring high driving force and high grip, such as climbing hills, slippery roads, and overtaking at high throttle. In this way, by synchronously constraining multiple conditions such as even-numbered shaft engagement, front motor electric drive output, and rear motor operation, the four-wheel drive conditions of the front and rear motors are accurately identified, clearly distinguishing them from pure electric two-wheel drive. The identification results can provide the maximum driving force alternative for subsequent direct drive failure conditions, supporting the core control logic of "prioritizing the retention of four-wheel drive when direct drive is unavailable," and solving the defect of existing solutions that directly switch series drives, resulting in driving force attenuation.

[0030] Step 104-13: In response to the engine being in the start state, the clutch being in the even-numbered shaft gear closed state, the even-numbered shaft synchronizer being in the neutral position, the odd-numbered shaft synchronizer being in the neutral position, the front motor being in the engine drive mode, the front motor being in the generator state, and the rear motor being in the start state, determine that the current power transmission working mode is the series mode.

[0031] In this step, when the engine is in the started state, the clutch is in the even-numbered shaft gear closed state, the even-numbered shaft synchronizer is in the neutral position, the odd-numbered shaft synchronizer is in the neutral position, the front motor is in engine drive mode, the front motor is in generator mode, and the rear motor is in the started state, that is, when the engine is in the started state, the clutch is in the even-numbered shaft gear closed state (i.e., K2 is engaged), the even-numbered shaft synchronizer and the odd-numbered shaft synchronizer are both in the neutral position, the front motor is in engine drive mode, the front motor is in generator mode, and the rear motor is in the started state; and the transmission system status information is as described above, the current power transmission operating mode is series mode. The operating logic of the series mode is as follows: when the engine is ignited and running, the clutch K2 gear is closed to establish a mechanical connection between the engine and the even-numbered shaft and the front motor; when the synchronizer of the even-numbered shaft is in neutral, the mechanical path from the front motor to the front wheel is cut off, and all the engine torque is used to drive the front motor; when the front motor is working in the generator mode, the generated electrical energy is supplied to the rear motor of the rear axle, and the rear wheels are driven only by the rear motor, and the front axle has no mechanical driving force output.

[0032] In this embodiment, the engine is ignited and running, clutch K2 is engaged, and a mechanical connection is established between the engine and the front motor. All synchronizers on both odd and even shafts are in neutral, cutting off the mechanical transmission from the front motor to the front wheels. All engine torque is used to drive the front motor to generate electricity. The electricity generated by the front motor supplies the rear motor, and the entire vehicle is driven solely by the rear axle motor. This system balances battery charging and basic driving power, and is often used in scenarios with low battery charge or direct-drive hardware failure. Thus, by using the three core characteristics of synchronized K2 engagement, dual-shaft synchronizer neutral engagement, and front motor power generation, the system accurately distinguishes the series-driven power generation mode, preventing confusion with the direct-drive mode. It can accurately identify special conditions where only the rear axle outputs power and the engine only generates electricity without driving the wheels, providing a reliable basis for switching to series charging under low battery conditions and limiting power output in fault conditions, protecting the battery from deep discharge.

[0033] Steps 104-14: In response to the engine being in the started state, the clutch being in the odd-numbered gear engaged state, the odd-numbered shaft synchronizer being in the odd-numbered gear position, the front motor being in the started state, and the rear motor being in the started state, or... In response to the engine being in the started state, the clutch being in the even-numbered gear engaged state, the even-numbered shaft synchronizer being in the even-numbered gear position, the front motor being in the started state, and the rear motor being in the started state, the current power transmission operating mode is determined to be direct drive mode.

[0034] In this step, when the engine is running, the clutch is in odd-numbered gear engaged, the odd-numbered shaft synchronizer is in odd-numbered gear position, and both the front and rear motors are running—that is, when the engine is running, the clutch is in odd-numbered gear engaged (K1 engaged), the odd-numbered shaft synchronizer is engaged in odd-numbered gears (G1 / G3), and both the front and rear motors are running—the current power transmission mode is direct drive. The operating logic of direct drive under this condition is as follows: the engine connects to the odd-numbered shaft via clutch K1, the odd-numbered shaft synchronizer engages in odd-numbered gear, and the engine's mechanical power is directly transmitted to the front wheels; the front and rear motors operate simultaneously, coordinating torque output to achieve engine direct drive + front and rear motor assistance, resulting in optimal overall vehicle drive force output.

[0035] Alternatively, when the engine is running, the clutch is in an even-numbered gear engaged, the even-numbered shaft synchronizer is in an even-numbered gear position, the front motor is running, and the rear motor is running—that is, the engine is running, the clutch is in an even-numbered gear engaged (K2 engaged), the even-numbered shaft synchronizer is engaged in G2 / G4 even-numbered gears, and both the front and rear motors are running—the current powertrain operating mode is direct drive mode. The operating logic of direct drive mode under this condition is as follows: the engine connects to the even-numbered shaft via clutch K2, the even-numbered shaft synchronizer engages in an even-numbered gear, and the engine's mechanical power is directly transmitted to the front wheels; the front and rear motors synchronously participate in the drive, superimposed with the engine's torque output. Direct drive mode is suitable for: high-speed overtaking, long-distance hill climbing, when the driver has a continuous high torque demand, and when there are no faults in the relevant direct drive transmission components, the vehicle enters direct drive mode.

[0036] In this embodiment, two sets of parallel judgment conditions are set, and satisfying either set determines direct drive. The first set is for odd-gear direct drive: clutch K1 is engaged, odd-gear shaft is engaged with G1 / G3, the engine mechanically drives the front wheels via the odd-gear shaft, and the front and rear motors operate synchronously to assist. The second set is for even-gear direct drive: clutch K2 is engaged, even-gear shaft is engaged with G2 / G4, the engine drives the front wheels via the even-gear shaft, and the front and rear motors output torque synchronously. Direct drive is the mode with the highest power limit of the whole vehicle, which is suitable for high-speed and continuous high torque requirements. In this way, both odd-gear and even-gear direct drive paths are covered, which fully adapts to all engine mechanical direct drive conditions of this architecture. By jointly verifying the clutch engagement gear and synchronizer engagement status, it is possible to distinguish between direct drive with partial faults and direct drive with complete failure, providing an accurate condition identification basis for selecting the corresponding slip-start strategy for direct drive-limited scenarios. It accurately identifies the maximum driving force condition of the whole vehicle, ensuring that direct drive operation is maintained first when high torque is required.

[0037] In steps 104-11 to 104-14, by jointly determining multiple dimensions of parameters such as clutch, synchronizer, and motor start / stop / operation status, it can accurately distinguish four completely different transmission structures: pure electric two-wheel drive, pure electric four-wheel drive, series drive, and direct drive. This avoids mode misjudgment and omission, ensuring the vehicle controller accurately identifies the current driving condition. It distinguishes subdivided states such as motor drive / generator, clutch engagement gear, and synchronizer position, fully covering all normal operating conditions of this hybrid architecture and adapting to various scenarios such as fault restriction and normal driving. The mode recognition is completed based on the actual physical state of the hardware, and the recognition results can be directly used as the input basis for subsequent screening of available power modes and switching of target power transmission operating modes, ensuring the consistency of the data source for the entire control logic. The judgment logic is clearly layered, with clear and non-overlapping judgment conditions set for each type of mode. The controller's operation logic is simple and efficient, reducing the vehicle control operation load and improving the mode recognition response speed. Meanwhile, the four modes are independent of each other and do not overlap or conflict. They rely on the joint judgment of the real physical state of the multi-dimensional hardware, such as the clutch, synchronizer, motor start / stop, and motor working mode, to avoid misjudgment or omission of modes and achieve high accuracy in working condition identification. They also distinguish between four power output levels: pure electric two-wheel drive, pure electric four-wheel drive, series drive, and direct drive, fully covering all normal driving, fault-limited, and low-battery charging conditions of hybrid vehicles, and adapting to all-scenario control needs.

[0038] Furthermore, based on the previously collected status information of the entire transmission system, including the clutch, gearbox, front and rear motors, and synchronizer positions, a graded fault flag corresponding to four power modes is first generated. Then, based on the fault flag, three modes are distinguished: completely unusable, partially restricted, and fault-free. Available power transmission operating modes that are allowed to operate under hardware conditions are selected, providing a candidate set for subsequent selection of the target power transmission operating mode with the maximum driving force. Specifically, determining the available power transmission operating modes based on the transmission system status information includes the following steps: Step 104-21: Determine the fault flag information of the power transmission working mode based on the transmission system status information.

[0039] In this step, based on the collected status of various transmission hardware such as clutches, gearboxes, synchronizers, and front and rear motors, standardized fault flag information is generated for four power transmission modes: direct drive, pure electric four-wheel drive, pure electric two-wheel drive, and series drive. The fault flags are divided into two categories: mode completely unusable fault flags and partially restricted fault flags (e.g., odd gear fault of clutch or even gear fault of clutch). Different component abnormalities will generate corresponding power mode fault labels, completing the conversion of hardware faults into mode availability labels.

[0040] For example, if a clutch K2 gear malfunction is detected, a fault flag indicating that the series mode is completely unavailable and a fault flag indicating that the direct drive even-numbered gear is unavailable will be generated simultaneously. If a front motor hardware malfunction is detected, fault flags indicating that the pure electric four-wheel drive mode and the series mode are completely unavailable will be generated simultaneously. In this embodiment, scattered component fault signals are uniformly converted into standardized fault identifiers corresponding to the corresponding power modes, distinguishing between two fault levels: complete failure and partial limitation. This simplifies the subsequent availability judgment logic and provides a basis for determining differentiated engine start-up and mode switching strategies under fault conditions.

[0041] Specifically, the transmission system status parameters used to determine fault indicators include clutch fault status, gearbox fault status, clutch in gear status, odd-numbered shaft synchronizer gear status, even-numbered shaft synchronizer gear status, front motor fault status, and rear motor fault status. The vehicle includes four powertrain operating modes: direct drive mode, pure electric four-wheel drive mode, pure electric two-wheel drive mode, and series mode. The vehicle controller, based on the above hardware status, generates fault indicators corresponding to each mode through six branches. Specifically, the transmission system status information includes: clutch fault status, gearbox fault status, clutch in gear status, odd-numbered shaft synchronizer gear status, even-numbered shaft synchronizer gear status, front motor fault status, and rear motor fault status. The power transmission operating modes include: direct drive mode, pure electric four-wheel drive mode, pure electric two-wheel drive mode, and series mode; The step of determining the fault flag information of the power transmission operating mode based on the transmission system status information includes the following steps: Steps 104-211: In response to the clutch fault state being either an odd-numbered gear fault or an even-numbered gear fault, or the transmission fault state being that all gears of the transmission are damaged, determine that the fault flag information for the direct drive mode is an unavailable fault flag.

[0042] In this step, the transmission system status parameters used to determine the fault signs include clutch fault status, gearbox fault status, clutch in gear status, odd-numbered shaft synchronizer gear status, even-numbered shaft synchronizer gear status, front motor fault status, and rear motor fault status. The vehicle includes four power transmission operating modes: direct drive mode, pure electric four-wheel drive mode, pure electric two-wheel drive mode, and series mode. The vehicle controller combines the above hardware status to generate the fault signs corresponding to each mode in six branches.

[0043] For example, if the TCU reports a fault in both the K1 and K2 gears of the clutch while the vehicle is in motion, the controller determines that the direct drive mode is unavailable; or if all four gears of the transmission fail, a direct drive unavailable fault flag is generated. This judgment condition enables accurate identification of the condition where the direct drive mode is completely unavailable, marking in advance that the maximum driving force mode of the entire vehicle is completely unusable, thus preventing subsequent control logic from attempting to switch to direct drive mode and causing switching failure and power interruption.

[0044] Steps 104-212: In response to the clutch fault state being an odd gear fault or the odd shaft synchronizer being in an unavailable gear state, determine the fault flag information of the direct drive mode as a clutch odd gear fault flag.

[0045] In this step, a type of partially restricted fault flag is marked in the direct drive mode, where only the transmission path corresponding to the odd gear fails: either the clutch K1 gear fails and cannot engage, or the odd shaft synchronizer cannot engage the G1 / G3 gear. Only the odd gear direct drive path fails, while the hardware of the even gear direct drive path is intact and can still work normally. Only the clutch odd gear fault flag is generated, that is, a partially restricted fault flag one (in this embodiment, the odd gear fault flag) is generated instead of a completely unusable fault flag.

[0046] For example, if a fault is detected in clutch K1, the controller generates a fault flag for odd-numbered clutch gears. The vehicle can still use clutch K2 and even-numbered gears to complete direct drive. This embodiment distinguishes between partial and complete direct drive faults, and will not directly disable the direct drive mode due to the failure of a single gear path. It retains the direct drive capability of another set of intact gears, maintaining the maximum driving force output capability under fault conditions.

[0047] Steps 104-213: In response to the clutch fault state being an even-numbered gear fault or the even-numbered shaft synchronizer being in an unavailable gear state, determine the fault flag information of the direct drive mode as a clutch even-numbered gear fault flag.

[0048] In this step, another type of direct drive partial restriction fault is marked, where only the even-numbered gear transmission path fails: the clutch K2 gear is faulty or the even-numbered shaft synchronizer cannot engage G2 / G4 gear, the even-numbered gear direct drive cannot be used, but the odd-numbered gear direct drive hardware is normal, only the clutch even-numbered gear fault flag is generated, that is, the partial restriction fault flag two is generated (in this embodiment, the even-numbered gear fault flag).

[0049] For example, if the even-numbered shaft synchronizer is stuck and cannot engage an even-numbered gear, a direct-drive even-numbered gear fault flag is generated, and the vehicle can continue direct drive normally using K1 and odd-numbered gears. In this embodiment, in conjunction with the previous step, a dual-path fault stratification marking for direct drive is completed, accurately distinguishing between odd-numbered and even-numbered gear single-sided faults, providing a basis for judgment to match the corresponding engine slip-start strategy after a fault occurs.

[0050] Steps 104-214: In response to the transmission fault state being all gears of the transmission damaged, the front motor fault state being damaged, or the rear motor fault state being damaged, determine that the pure electric four-wheel drive mode is an unavailable fault sign.

[0051] In this step, the pure electric four-wheel drive relies on the front motor to drive the front wheels via even-numbered shafts and the rear motor to drive the rear wheels. Any of the three types of faults will disrupt the four-wheel drive power link: all gears are damaged and cannot engage even-numbered gears to transmit power to the front motor; the front motor is damaged and there is no driving force for the front wheels; the rear motor is damaged and there is no driving force for the rear wheels. If any of these conditions are triggered, the pure electric four-wheel drive cannot be established at all, and an unusable fault flag will be marked.

[0052] For example, if the front motor controller reports a hardware malfunction, the controller directly determines that the pure electric four-wheel drive is unavailable and can only switch to pure electric two-wheel drive or series mode for driving. In this embodiment, if the front motor controller reports a hardware malfunction, the controller directly determines that the pure electric four-wheel drive is unavailable and can only switch to pure electric two-wheel drive or series mode for driving.

[0053] Steps 104-215: In response to the front motor being damaged and the rear motor being damaged, determine that the pure electric two-wheel drive mode is an unavailable fault flag.

[0054] In this step, the pure electric two-wheel drive relies solely on the rear motor to drive the rear wheels. Only when both the front and rear motors fail simultaneously, resulting in no pure electric power source for the entire vehicle, is the pure electric two-wheel drive deemed unusable. A failure of only one side motor will not trigger this flag, and the pure electric two-wheel drive can be maintained as long as the rear motor is intact.

[0055] For example, if both the front and rear motors report hardware failures simultaneously, the entire pure electric driving path of the vehicle becomes unusable, generating a pure electric two-wheel drive unavailable fault flag and a pure electric four-wheel drive unavailable fault flag. The vehicle can only drive in series or direct drive mode. In this embodiment, the failure boundary of the pure electric two-wheel drive is accurately distinguished. Pure electric rear drive is only disabled if both the front and rear motors fail simultaneously. A single motor failure still retains the basic pure electric driving capability, improving the fault tolerance range of pure electric operating conditions.

[0056] Steps 104-216: In response to the clutch fault state being an even-numbered gear fault, the even-numbered shaft synchronizer being unavailable in its gear position, or the front motor being damaged, determine that the fault flag information for the series mode is an unavailable fault flag.

[0057] In the process, the series mode relies on three hardware components: the clutch K2 gear (represented as an even gear) connecting the engine and the front motor, the even-numbered shaft synchronizer being in neutral, and the front motor generating electricity. If any of these three components fails, the series power generation drive link will break: a clutch K2 gear failure will prevent the connection between the engine and the front motor; an even-numbered shaft synchronizer failure to be in neutral will result in the front axle having driving force; and damage to the front motor will prevent it from generating electricity. If any of these conditions are met, the series mode is deemed unusable.

[0058] For example, when the clutch K2 gear fails, the controller generates a series unavailable fault flag. In low-battery conditions, the series generator cannot be started, and the vehicle can only operate in pure electric mode. This embodiment fully covers the hardware conditions for series mode failure, allowing for early identification of series charging failure in low-battery scenarios. Subsequent control logic then switches strategies in a timely manner to mitigate the risk of deep battery depletion.

[0059] In steps 104-211 to 104-216, "completely unusable fault flags" and "partially restricted fault flags" are generated hierarchically for the four types of power modes through multiple independent decision branches, fully covering all hardware fault scenarios of clutch, transmission, synchronizer, and front and rear motors; for partial faults of a single gear or a single motor, only the restricted state is marked, while the remaining intact power paths are preserved, and the high-drive-force mode is not disabled in a one-size-fits-all manner; the standardized fault flags can be directly used for subsequent screening of available modes and matching of differentiated engine start-stop strategies, realizing the unified logic of the entire chain of fault identification, mode screening, and power switching.

[0060] Step 104-22: Determine the available power transmission working modes based on the fault flag information of the power transmission working modes.

[0061] In this step, available power modes are selected based on the various fault flags generated in the previous step. If a power transmission mode has a completely unusable fault flag, the mode is removed. Power modes with only partially limited fault flags or no fault flags are all determined to be available power transmission working modes. Finally, a set of candidate modes that are supported by all hardware conditions is output.

[0062] For example, when the system has a series completely unavailable fault flag and a direct drive partially restricted fault flag, only the series mode is eliminated, while the direct drive mode, pure electric four-wheel drive mode, and pure electric two-wheel drive mode are retained as available modes. If both the direct drive mode and the pure electric four-wheel drive mode trigger the completely unavailable fault flag, only the pure electric two-wheel drive mode is retained as an available mode. This embodiment preemptively filters out power modes with completely failed hardware, avoiding the risk of switching failure and power interruption. Power modes marked with partially restricted fault flags are retained to fully utilize intact transmission paths, improve the vehicle's power redundancy under fault conditions, and provide an effective candidate range for downstream selection of target power transmission modes with greater driving force.

[0063] Specifically, determining the available power transmission operating mode based on the fault flag information of the power transmission operating mode includes: The power transmission operating mode in which the fault flag information is the clutch odd gear fault flag, the clutch second gear fault flag, or the fault flag information is empty is designated as the available power transmission operating mode.

[0064] In this step, based on the fault flag information of each power transmission mode generated in the previous step, the criteria for determining the usable modes are defined, distinguishing two categories of power transmission modes that can be used normally: The first category is power transmission modes with only partial restricted fault flags, including direct drive modes with only odd-numbered clutch gear fault flags and only even-numbered clutch gear fault flags; in this type of mode, only one side of the gear transmission path is failed, while the gear hardware on the other side is intact, and direct drive can still be achieved by relying on the intact gear, so it is not eliminated; The second category is power transmission modes with no fault flag information, which means that all transmission components in this mode are normal and the complete power transmission path can be used normally; any power transmission mode marked with a completely unusable fault flag is not included in the set of usable power transmission working modes and is directly eliminated.

[0065] For example, the direct drive mode only has a clutch even-number gear fault indicator, the pure electric four-wheel drive and pure electric two-wheel drive have no fault indicators, and the series mode has a completely unusable fault indicator; according to the rules, the direct drive mode, pure electric four-wheel drive mode and pure electric two-wheel drive mode are determined to be usable power transmission working modes, and the series mode is eliminated.

[0066] The direct drive mode has a clutch odd gear fault indicator, while the other four modes have no fault indicator; all direct drive, pure electric four-wheel drive, pure electric two-wheel drive, and series drive modes are all determined to be usable modes.

[0067] The direct drive mode has a completely unavailable fault sign, the pure electric four-wheel drive has a completely unavailable fault sign, and the pure electric two-wheel drive has no fault sign; only the pure electric two-wheel drive is the only available power transmission mode.

[0068] The direct drive mode has a completely unavailable fault sign, the pure electric four-wheel drive has a completely unavailable fault sign, and the pure electric two-wheel drive has no fault sign; only the pure electric two-wheel drive is the only available power transmission mode.

[0069] In this embodiment, partial faults and complete failure faults are distinguished in layers. The direct drive high-power mode is not directly abandoned due to single-sided clutch or gear path failures. This maximizes the retention of the vehicle's power output capability under fault conditions and alleviates the problem of drive force attenuation after a fault in existing solutions. The judgment rules are clear and unified. Mode selection can be quickly completed by simply using the fault flag type, reducing the logic operation load of the vehicle controller and improving the mode selection response speed. A standardized set of available mode candidates is output, providing accurate input for subsequent selection of the target power transmission working mode with the maximum drive force based on the remaining battery power.

[0070] In steps 104-21 to 104-22, a two-level hierarchical logic of fault flags and availability screening of power transmission working modes is used to complete the determination of available modes. Based on the actual hardware status of the transmission system, the degree of failure of the driving force path is distinguished. This not only shields the complete failure mode that poses safety and operational risks, but also prevents the entire power system from being completely disabled due to a partial failure of a single component, thus greatly improving the driving fault tolerance and power performance of hybrid vehicles in fault conditions.

[0071] Step 106: Based on the operating status information, determine a target power transmission operating mode among the available power transmission operating modes that can provide the vehicle with a driving force greater than that provided by the current power transmission operating mode.

[0072] In this step, the vehicle's power output capability, from highest to lowest, is as follows: direct drive mode, pure electric four-wheel drive mode, pure electric two-wheel drive mode, and series mode. It should be noted that in this embodiment, the vehicle's power output capability refers to the wheel-end driving force output capability. The upper limit of the driving force in the pure electric two-wheel drive mode and the series mode is consistent. The vehicle controller uses the remaining battery charge as the core constraint condition and selects the target power transmission mode from the set of available power transmission operating modes output in the above steps, based on different scenarios: When the remaining battery charge is greater than or equal to a preset charge threshold, the mode with the highest driving force output capability among the available modes is directly selected as the target power transmission operating mode; when the remaining battery charge is less than the preset charge threshold, and the available modes include series mode but not direct drive mode, the series mode is selected as the target power transmission operating mode, relying on the engine to generate electricity to maintain vehicle operation and replenish battery charge; when the remaining battery charge is less than the preset charge threshold, and there is neither direct drive mode nor series mode among the available modes, the current operating mode is not switched, and the current power transmission operating mode is directly used as the target power transmission operating mode. For example, if the available modes include direct drive mode and pure electric four-wheel drive mode, and the battery has sufficient remaining charge, the direct drive mode with the best power performance (i.e., the greatest driving force) is selected first. If the direct drive mode is unavailable due to a fault, the battery charge is low, and the series mode hardware is intact, the series mode is selected. If both direct drive and series modes fail, the current operating mode remains unchanged. This step addresses the defect of existing control strategies that force a switch to series mode after direct drive failure, resulting in power attenuation. It meets the driver's demand for high torque driving force while also protecting the power battery energy. Under low charge conditions, it prioritizes the use of series generators to avoid deep battery depletion and damage to the battery cells. The multiple decision logic can maintain the original driving state when all oil drive modes fail, significantly reducing the probability of sudden power loss of the vehicle.

[0073] Specifically, this application limits the operating status information to include only the remaining power battery charge (State of Charge, SOC). The power output capability priority of the four power modes of the vehicle is fixed as follows: direct drive mode > pure electric four-wheel drive mode > pure electric two-wheel drive mode = series mode. The vehicle controller uses a preset charge threshold as a boundary to filter the target power transmission working mode in three categories of charge conditions, taking into account both the driver's high torque driving force requirements and the power battery's anti-discharge protection requirements. Specifically, the operating status information includes: remaining power charge; The step of determining, based on the operating status information, a target power transmission operating mode that can provide the vehicle with a driving force greater than that provided by the current power transmission operating mode among the available power transmission operating modes includes the following steps: Step 1061: In response to the remaining power being greater than or equal to a preset power threshold, the power transmission mode with the maximum driving force among the available power transmission modes is taken as the target power transmission mode.

[0074] In this step, when the remaining battery power is greater than or equal to the preset battery power threshold, it indicates that the power battery has sufficient remaining power. When the remaining battery power is sufficient and reaches or exceeds the system's preset battery power threshold, the battery discharge power can fully support the continuous output of the pure electric high-drive-force mode, without the need to prioritize starting the engine to generate electricity for supplementary power. The vehicle controller directly selects the highest-ranked mode with the highest upper limit of drive force output from the set of all available power modes output in the above embodiment, according to the priority of drive force performance in the order of "direct drive mode > pure electric four-wheel drive mode > pure electric two-wheel drive mode = series mode", as the target power transmission working mode. This prioritizes matching the driver's high torque demand for high throttle, climbing, and overtaking, without actively limiting power output.

[0075] For example, the preset battery power threshold is set to 20%, and the current battery remaining power (SOC) is 35% (≥20%); the available mode set includes direct drive mode, pure electric four-wheel drive, and pure electric two-wheel drive, with the maximum driving force being direct drive mode, and direct drive mode is determined as the target power transmission working mode.

[0076] The current remaining battery power is 28%. The fault flag information for direct drive mode is an unavailable fault flag. Therefore, direct drive mode is eliminated due to the unavailable fault flag. The available modes are pure electric four-wheel drive mode and pure electric two-wheel drive mode. The pure electric four-wheel drive mode with stronger driving force is selected as the target power transmission working mode.

[0077] The current remaining battery level is 40%. The fault indicators for both direct drive mode and pure electric four-wheel drive mode are "unavailable." Therefore, direct drive mode and pure electric four-wheel drive mode are excluded due to these unavailable fault indicators. Only pure electric two-wheel drive and series mode are available, and their power limits are the same. Either mode can be selected as the target power transmission mode. In this embodiment, the preset battery level threshold can be set based on ambient temperature, battery discharge power, vehicle speed, or actual conditions. A common setting is 20%-30%, but the specific setting of the preset battery level threshold is not discussed here.

[0078] In this embodiment, when the battery is fully charged, the vehicle's maximum power is released first, completely solving the defect of the existing technology where the forced switching to series drive after direct drive failure leads to a significant decrease in driving force. This matches the driver's power expectation when pressing the accelerator hard, improving the acceleration and hill-climbing driving experience. The control logic is simple and intuitive, with high controller efficiency and faster mode switching response under high torque requests, using only power strength as the selection criterion. It makes full use of the power battery's surplus power, reduces unnecessary engine starts, lowers fuel consumption and noise, and balances the vehicle's power and economy.

[0079] Step 1062: In response to the remaining power being less than a preset power threshold, the available power transmission operating modes not including direct drive mode and the available power transmission operating modes including series mode, the series mode is taken as the target power transmission operating mode.

[0080] In this step, when the remaining battery power is less than a preset threshold, it indicates that the remaining battery power is insufficient. When the remaining battery power is low, below the preset threshold, and a hardware failure renders the direct drive mode, which offers the strongest driving force, completely unavailable, but the series mode hardware path is intact and can operate normally, the vehicle controller selects the series mode as the target mode. In series mode, the engine drives the front motor to continuously generate electricity, which supplies the rear motor on the rear axle to drive the vehicle. This ensures basic driving power while continuously replenishing the battery power, preventing cell damage and vehicle power limitation caused by continuous deep discharge. This logic is only triggered when direct drive is completely unavailable; if direct drive is available, it will still be the preferred mode.

[0081] For example, with a preset battery threshold of 20% and the current remaining battery level at only 15%, the fault indicator in direct drive mode is an unavailable fault indicator, while the fault indicator in series mode is empty, indicating that series mode is available. The controller switches to series mode, and the engine starts to generate electricity to drive the vehicle and replenish the battery. It should be noted that in series mode, the engine starts to drive the front motor to generate electricity.

[0082] The current remaining battery power is 12%. The fault flag information for direct drive mode is "unavailable" and the fault flag information for pure electric four-wheel drive mode is "unavailable". The available modes are pure electric two-wheel drive and series mode. The series mode is selected first, relying on the engine to generate electricity to prevent the battery from continuously depleting.

[0083] Step 1063: In response to the remaining power being less than a preset power threshold and the available power transmission operating modes not including direct drive mode and series mode, the current power transmission operating mode is taken as the target power transmission operating mode.

[0084] In this step, when the remaining battery power is less than the preset threshold, it indicates that the remaining battery power is insufficient. When the remaining battery power is below the preset threshold, and the fault flags for both direct drive mode and series mode are unavailable, it means that both types of hybrid modes with an engine are completely unavailable due to hardware failure. The vehicle has no power generation path and cannot replenish the battery power through the engine. At this time, the controller does not actively switch to a new power mode, but directly maintains the current power mode of the vehicle without initiating a mode switching action. This avoids frequent switching to pure electric mode, which accelerates battery consumption, while continuously reminding the driver of the risk of battery depletion.

[0085] For example, with a preset battery threshold of 20% and a current remaining battery of 13%, the fault flag information for both direct drive mode and series mode carries an unavailable fault flag, and only pure electric two-wheel drive is available. If the vehicle is currently running pure electric two-wheel drive, the target mode will remain pure electric two-wheel drive, and no switching will be performed. The current remaining battery level is 10%. The fault indicator for both direct drive mode and series drive mode is "unavailable" (a clutch K2 gear malfunction causes series drive unavailability). The vehicle is currently operating in pure electric four-wheel drive mode, so it will continue to drive in pure electric four-wheel drive mode. Simultaneously, the vehicle's instrument panel will display a low battery warning. In this embodiment, under extreme low battery conditions where both the hydraulic drive mode and generator mode are unavailable, the power mode is not forcibly switched to reduce the additional energy consumption caused by frequent gearbox and clutch operation, thus slowing down the battery depletion rate. The strategy of maintaining the existing mode avoids torque fluctuations and jerking caused by multiple mode switching, ensuring driving stability. The power limit is locked in advance, and the fault warning allows the driver to promptly understand the risk of battery depletion, facilitating adjustments to driving intensity and preventing the vehicle from losing power mid-journey.

[0086] In steps 1061-1063, the remaining battery power is used as the core of the hierarchical judgment. A three-level progressive screening logic is established in combination with the hardware status of the available power transmission modes: when the battery power is sufficient, the high torque driving force demand of the driver is prioritized; when the battery power is low and there is a series path, the generator is activated to protect the battery; when there is no generator path, the existing operating conditions are maintained for backup driving. This perfectly overcomes the pain point of the existing control strategy of forcibly switching to series after a direct drive failure, resulting in a significant reduction in driving force. At the same time, the hierarchical approach takes into account the overall vehicle power performance, power battery energy protection, and driving stability under extreme fault conditions, and fully covers the mode selection needs of full battery power and all fault scenarios under high torque request.

[0087] In some embodiments, the power sources included in different types of target powertrain operating modes are clearly distinguishable. Pure electric four-wheel drive mode and pure electric two-wheel drive mode rely solely on electric motor drive and do not require engine start, while direct drive mode and series mode require synchronous engine participation in power output. If mode switching is performed directly without prior identification of the power source type and without matching an appropriate engine start scheme based on the current transmission hardware fault state, problems such as blind engine start without strategy, engine start failure under clutch and synchronizer failure conditions, drastic torque fluctuations during the switching process, and interruption of driving force can easily occur. Therefore, it is necessary to first identify the power source composition of the target powertrain operating mode, and only when the power source includes an engine, to match the corresponding engine start control strategy in combination with transmission system status information and fault flag information, providing a preliminary control basis for the subsequent smooth and reliable completion of mode switching. Specifically, the following steps are also included: Step 1071: Determine the power source in the target power transmission working mode.

[0088] In this step, the vehicle controller reads the target powertrain operating modes obtained from the above screening and, referring to the power source composition rules corresponding to the four types of powertrain operating modes, identifies all power sources participating in the output drive torque within the target powertrain operating mode. The power sources for each powertrain operating mode are fixedly divided as follows: direct drive mode includes the engine, front motor, and rear motor; series mode includes the engine, front motor, and rear motor; pure electric four-wheel drive mode includes the front motor and rear motor, but not the engine; pure electric two-wheel drive mode includes only the rear motor, but not the engine. After the vehicle controller completes the matching, it marks whether the target powertrain operating mode includes the engine as a power source, providing a basis for determining whether to activate the engine start control strategy subsequently.

[0089] For example, if the selected target powertrain mode is direct drive, matching will determine that the power source in this mode is the engine, front motor, and rear motor. If the selected target powertrain mode is pure electric four-wheel drive, matching will determine that the power source in this mode is the front motor and rear motor, with no engine power source. If the selected target powertrain mode is series drive, matching will determine that the power source in this mode is the engine, front motor, and rear motor. If the selected target powertrain mode is pure electric two-wheel drive, matching will determine that the power source in this mode is only the rear motor.

[0090] In this embodiment, the system accurately distinguishes whether the target powertrain operating mode requires engine startup, thereby achieving control logic offloading. For pure electric four-wheel drive and pure electric two-wheel drive modes without an engine, the engine startup strategy matching process can be skipped directly, reducing invalid calculations by the vehicle controller and improving the mode switching response speed. The system standardizes the power source identification standard, which fully corresponds to the definitions of the four types of powertrain operating modes, ensuring the consistency of the vehicle controller's judgment logic and avoiding control defects such as engine misstart or missed start. The system provides a clear and unique pre-judgment condition for the next-level engine startup strategy matching step, achieving two-level logic connection between power source identification and engine startup control.

[0091] Step 1072: In response to the power source including the engine, determine the engine start control strategy based on the transmission system status information, the fault flag information and the target power transmission operating mode.

[0092] In this step, when the power source of the identified target powertrain operating mode includes an engine, the vehicle controller synchronously retrieves three types of basic data as the basis for starting strategy matching. These three types of data are: the collected transmission system status information, the generated fault flag information for the powertrain operating mode, and the determined target powertrain operating mode. Combining the combined status of these three types of data, a unique engine starting control strategy is matched to adapt to the current hardware fault, synchronizer gear position, and target operating mode. The engine starting control strategy includes three complete naming formats: front motor-driven engine starting strategy, clutch odd-gear slip start strategy, and clutch even-gear slip start strategy. Each starting control strategy corresponds to a unique condition for different transmission hardware states, different fault flag information, and different target powertrain operating modes, with no abbreviations or mixed descriptions. If the target powertrain operating mode does not include an engine power source, the strategy matching operation corresponding to this step is not executed, and the powertrain mode switching process is directly initiated.

[0093] For example, the target powertrain operating mode is direct drive mode, and the power source includes an engine; the fault indication information is an odd-numbered gear clutch fault, and the transmission system status information shows that the synchronizer position of the odd-numbered shaft is in neutral and the synchronizer position of the even-numbered shaft is in neutral; the vehicle controller matches the engine starting strategy driven by the front motor. The target powertrain operating mode is direct drive mode, and the power source includes an engine; the fault indication information is an odd-numbered gear clutch fault, and the transmission system status information shows that the synchronizer position of the even-numbered shaft is in even-numbered gear; the vehicle controller matches the clutch even-numbered gear slip-start strategy. The target powertrain operating mode is direct drive mode, and the power source includes an engine; the fault indication information is an even-numbered gear clutch fault, and the vehicle controller matches the clutch odd-numbered gear slip-start strategy. The target powertrain operating mode is series mode, and the power source includes an engine; the transmission system status information shows that the clutch operating status is even-numbered gear engaged and the synchronizer position of the even-numbered shaft is in neutral; the vehicle controller matches the engine starting strategy driven by the front motor.

[0094] In this embodiment, the starting strategy is determined by considering three dimensions: real-time status of the transmission hardware, fault classification identification, and target operating mode. Even under partial fault conditions in direct drive mode, the engine can still be started using an appropriate slip start method, preventing the engine from losing its starting capability due to a single-sided clutch or synchronizer failure, thus significantly improving the vehicle's power redundancy under fault conditions. At the same time, the engine starting control strategy is matched one-to-one with the fault scenario, avoiding the problem of starting failure and power interruption under hardware fault scenarios when a fixed single starting method is used, thereby improving the engine starting success rate. The strategy matching logic relies on the standardized data collected and generated in the previous section, and the terminology and judgment conditions remain consistent throughout the process. The entire control logic is coherent and unified, reducing the probability of software logic conflicts and judgment errors.

[0095] Specifically, based on the transmission system status information, the fault indicator information, and the target power transmission operating mode, an engine start-up control strategy is determined, including: In response to the target power transmission operating mode being direct drive mode, an engine start control strategy is determined based on the fault flag information of the direct drive mode and the transmission system status information.

[0096] In this step, when the vehicle controller needs to start the engine, it first identifies the target powertrain operating mode. If the target powertrain operating mode is determined to be direct drive mode, it separately retrieves the fault flag information corresponding to the direct drive mode and the transmission system status information including the position of the synchronizer on the odd-numbered shaft and the position of the synchronizer on the even-numbered shaft. Using these two types of parameters as the basis for judgment, it further refines and matches the engine-specific start control strategy adapted to the current hardware conditions.

[0097] Specifically, the transmission system status information includes the positions of the odd-numbered axis synchronizers and the even-numbered axis synchronizers; The step of determining the engine start control strategy based on the fault flag information of the direct drive mode and the transmission system status information includes: In response to the fault flag information of the direct drive mode being a clutch odd gear fault flag, the odd shaft synchronizer being in neutral, and the even shaft synchronizer being in neutral, the engine start control strategy is determined to be a front motor-driven engine start strategy.

[0098] Specifically, in the current direct-drive mode, only the odd-numbered gear fault indicator of the clutch is present, indicating that clutch K1 gear is faulty and the odd-numbered shaft transmission path is unusable, but clutch K2 gear and even-numbered shaft hardware are undamaged. Simultaneously, the vehicle controller reads the transmission system status information and identifies that both the odd-numbered and even-numbered shaft synchronizer positions are in neutral, with no gears engaged in the transmission. At this time, the mechanical conditions for coasting start-up are not met. The vehicle controller selects a front motor-driven engine starting strategy: controlling clutch K2 to close, relying on the intact even-numbered shaft mechanical link to connect the front motor and engine, with the front motor outputting stable torque to drive the engine to ignite and start; after engine ignition, the even-numbered shaft synchronizer is then engaged in an even-numbered gear to establish a direct drive path for the engine to the front wheels.

[0099] For example, the target power transmission operating mode is direct drive mode, the fault indication information is the odd-numbered gear clutch fault indication, the TCU feedback shows that the odd-numbered shaft synchronizer is in neutral, and the even-numbered shaft synchronizer is also in neutral. The controller matches the engine starting strategy driven by the front motor, first closing the clutch K2 gear, using the front motor to drive the engine to ignite, and after engaging the gear, entering the even-numbered gear for direct drive. In this embodiment, under the condition that both synchronizers are in neutral and the odd-numbered clutch is faulty, the engine is started by driving the front motor, avoiding the transmission shock and gear noise caused by slippage during starting without gear engagement; it makes full use of the intact clutch K2 gear and the even-numbered shaft passage to achieve engine ignition, and will not fail to start the engine due to a single-sided clutch failure, improving the fault tolerance of the driving force under fault conditions; the timing of starting the engine first and then engaging the driving gear avoids sudden changes in the transmission load during the starting phase, protecting the synchronizers and transmission gears.

[0100] In response to the fault flag information of the direct drive mode being a clutch odd-gear fault flag and the even-gear synchronizer being in an even-gear position, the engine start control strategy is determined to be a clutch even-gear slip start strategy.

[0101] Specifically, the current direct-drive mode fault flag is a clutch odd-gear fault flag, indicating that clutch K1 gear is unusable, while clutch K2 gear and the even-gear shaft transmission path are intact. The transmission system status information shows that the even-gear synchronizer has been pre-engaged in an even-gear position, and the even-gears of the transmission remain engaged, providing the mechanical basis for starting in gear. The vehicle controller selects a clutch even-gear slip-start strategy: controlling clutch K2 gear to engage slowly under slip-working conditions, relying on clutch slip-working to transmit torque, directly driving the engine to ignite via the reverse load of the wheels, without requiring the front motor to output a large drag torque separately; after the engine starts, clutch K2 gear is fully engaged, maintaining even-gear direct-drive driving.

[0102] For example, in direct drive mode, if there is a clutch odd-gear fault indicator, and the even-gear synchronizer is already engaged in the G2 even-gear position, the vehicle controller executes the clutch even-gear slip start strategy. The engine is started by transmitting torque through K2 slip start. After starting, the clutch is fully locked, and the engine directly drives the front wheels. In this embodiment, slip start is used when the even-gear is engaged, eliminating the synchronizer shifting action, shortening mode switching time, and providing faster drive force response under high torque requests. The engine is assisted by road load, reducing the starting torque requirement of the front motor, minimizing high-current discharge of the front motor, and saving battery power. Even-gear engagement is maintained throughout the process, allowing direct entry into stable direct drive conditions after starting without secondary shifting jerks, resulting in better driving smoothness.

[0103] It should be noted that slip start is a starting method that utilizes the clutch in a semi-engaged slipping state under gear conditions, using the vehicle's inertia to reverse-drive the engine for ignition. It is divided into K1 (odd-gear slip start) and K2 (even-gear slip start). The synchronizer needs to be pre-engaged in the corresponding driving gear, and the controller controls the clutch oil pressure to create a controllable speed difference between the primary and driven plates. The friction torque drives the crankshaft to the ignition speed. After successful engine ignition, the clutch is fully locked, entering direct drive operation. Its driving force comes from the vehicle's inertia, eliminating the need for a large drag torque output from the front motor and saving the gear shifting action after starting. The mode switching response is fast, but it is necessary to protect and control the slipping time, temperature, and oil pressure to avoid damage to the friction plates. This starting method is different from the front motor-driven engine starting strategy that requires the synchronizer to be in neutral and relies on the front motor's output torque to drag the engine. It is suitable for direct drive conditions where one side of the clutch fails.

[0104] In response to the fault flag information of the direct drive mode being a clutch even-gear fault flag, the engine start control strategy is determined to be a clutch odd-gear slip start strategy.

[0105] Specifically, the current direct-drive mode fault flag is a clutch even-gear fault flag, indicating that the clutch K2 gear and even-gear shaft transmission path are faulty, while only the clutch K1 gear and odd-gear hardware are intact. Regardless of whether the odd-gear synchronizer is in neutral or an odd gear, the vehicle controller uniformly matches the clutch odd-gear slip-start strategy. The execution logic is divided into two sub-scenarios: if the odd-gear synchronizer is already engaged in an odd gear, the clutch K1 gear is directly controlled to slip-engage, relying on the driving load to drive the engine for ignition; if the odd-gear synchronizer is in neutral, the synchronizer is first controlled to engage an odd gear, and then the clutch K1 gear slip-start is executed. After the engine ignites, the clutch is fully engaged, relying on the odd gear to achieve direct engine drive. For example, when the direct-drive mode fault flag is a clutch even-gear fault flag, the vehicle controller directly selects the clutch odd-gear slip-start strategy; if the current odd-gear synchronizer is in neutral, the controller first controls the synchronizer to engage the G1 odd gear, and then controls the clutch K1 gear to slip-start the engine. In this embodiment, a differentiated starting strategy matching the mechanical structure is set for all combinations of operating conditions, including single-sided clutch failure and different synchronizer gear positions in direct drive mode. This fully covers direct drive partial fault scenarios and avoids engine start failure. By jointly determining the dual conditions of fault flag and synchronizer position, two starting methods are distinguished: front motor driven start and clutch slip start. Different gearbox gear states are matched to reduce transmission shock, abnormal noise, and component wear. The three branches are mutually exclusive and the judgment boundaries are clear, forming a clear distinction from the single starting strategy of the series mode mentioned above. This achieves logical isolation between the two types of starting modes, including direct drive and series, and the control program has no logical conflicts. After all starting strategies are matched, a unified standard command is output, providing a precise timing sequence for the coordinated control of the engine, clutch, and synchronizer in the mode switching process. This ensures continuous power and no significant torque interruption during the direct drive mode switching process.

[0106] Furthermore, based on the transmission system status information, the fault flag information, and the target power transmission operating mode, an engine start-up control strategy is determined, including: In response to the target power transmission operating mode being a series mode, an engine start-up control strategy is determined based on the fault flag information of the series mode and the transmission system status information.

[0107] In this step, when the vehicle controller needs to start the engine, it first identifies the target powertrain operating mode. If the target powertrain operating mode is determined to be a series mode, it separately retrieves the fault flag information corresponding to the series mode, the transmission system status information of the odd-numbered shaft synchronizer position and the even-numbered shaft synchronizer position. Using these two types of parameters as the basis for judgment, it further refines and matches the engine-specific start control strategy adapted to the current hardware conditions.

[0108] Specifically, based on the fault flag information of the series mode and the transmission system status information, the engine start-up control strategy is determined, including: In response to the fault flag information of the series mode being no fault flag, the fault flag information of the direct drive mode not being a clutch even-numbered gear fault flag, the odd-numbered shaft synchronizer being in neutral, or the even-numbered shaft synchronizer being in neutral, the engine start control strategy is determined to be the front motor-driven engine start strategy.

[0109] In this step, all necessary conditions for starting the series mode are as follows: First, the fault indicator information for the series mode is a fault-free indicator, meaning that the clutch K2 gear, even-numbered shaft synchronizer, and front motor hardware are all fault-free, and the hardware path for series power generation is intact; Second, the fault indicator information for the direct drive mode is not a clutch even-numbered gear fault indicator, meaning that the clutch K2 gear can work normally and can establish a mechanical connection between the engine and the front motor; Third, the transmission system status information feedback shows that the odd-numbered shaft synchronizer position is in neutral and the even-numbered shaft synchronizer position is in neutral, meaning that neither the odd-numbered nor even-numbered shafts of the transmission are engaged in driving gears, preventing the transmission from outputting unnecessary driving torque to the front wheels during the start-up phase, which would disrupt the undriven working characteristics of the front axle in the series mode.

[0110] When all the above conditions are met simultaneously, the engine starting control strategy is determined to be the front motor-driven engine starting strategy. The execution sequence of this strategy is as follows: keep the odd-numbered shaft synchronizers and even-numbered shaft synchronizers in neutral, engage the clutch in gear K2, and the front motor outputs drag torque to drive the engine to rotate. After the engine reaches the ignition speed, it completes fuel injection and ignition. After the engine starts successfully, keep the dual-shaft synchronizers in neutral, and the engine drives the front motor to enter the generator mode. The generated electricity supplies the rear motor, which drives the vehicle to move independently.

[0111] If any one of the conditions is not met, the starting strategy will not be executed; for example, if there is an unavailable fault flag in the series mode, or if any synchronizer is not in neutral, it means that the mechanical conditions for the series mode operation are not met, the series mode is unavailable, and the engine start command will not be issued.

[0112] For example, the target power transmission operating mode is series mode. The fault sign information in series mode is no fault sign. In direct drive mode, there is no even-numbered gear fault sign for the clutch. The synchronizer positions of odd-numbered shafts and even-numbered shafts are both in neutral. The vehicle controller determines that the engine start control strategy is the front motor-driven engine start strategy. The clutch K2 gear is closed according to the procedure, and the engine is ignited by the front motor. Then it enters series mode operation.

[0113] The target power transmission operating mode is series mode. There is no fault indicator in series mode, but the even-number shaft synchronizer is in the even-number gear position, which does not meet all the conditions. The front motor to drive the engine starting strategy is not invoked, and the series mode cannot be started.

[0114] The target powertrain operating mode is series mode. In series mode, the fault indicator is normal, but in direct drive mode, there is a clutch even-numbered gear fault indicator, indicating a fault in clutch K2. The dual verification fails, and engine start in series mode is not executed. This embodiment uses a combination of multiple conditions—series fault indicator, secondary verification of K2 clutch status, and dual-shaft synchronizer neutral status—to ensure that the mechanical path fully meets the architecture requirements before starting in series mode. This avoids starting the engine while the synchronizer is engaged, which could cause unexpected torque output to the front wheels and lead to vehicle jerking. In series mode, only the front motor drives the engine for starting, avoiding slip start, which aligns with the mechanical constraint that the front axle must be in neutral in series mode, preventing overheating and damage to the friction plates due to abnormal clutch slip. A dual verification of the clutch K2 gear's availability status avoids starting failures caused by a single fault indicator, improving engine starting reliability. Only after all conditions are met is a uniquely determined starting strategy output, providing a clear coordinated control sequence for series mode switching and ensuring a smooth and safe transition.

[0115] In this embodiment, independent start-up judgment logic is set up for the two power modes that require engine starting, namely direct drive and series, which are isolated from each other. The direct drive mode combines its own local fault flag and the position of the dual synchronizers to distinguish three adaptation strategies: front motor driven start, odd / even gear slip start, etc. This fully covers various working conditions such as single-sided clutch failure, synchronizer neutral or gear engagement. It can avoid gear impact caused by slip without gear and protect transmission components. It can also shorten the switching time and reduce the power consumption of the front motor by relying on slip start, ensuring continuous and smooth driving force during the direct drive switching process. The series mode only uses front motor driven start. With the triple verification mechanism of series fault flag, K2 clutch status, and dual synchronizer neutral, it avoids the risk of abnormal clutch slip burn and front wheel lurching. The standardized start-up sequence is only executed after all hardware and gear conditions are met, so as to achieve a smooth switching of series power generation working conditions. The two types of start-up branches have clear boundaries and no logical conflicts, which greatly improves the engine start success rate under fault conditions, reduces transmission mechanism wear and vehicle torque fluctuation, and takes into account the driving force output under fault conditions, power battery energy consumption protection and component life.

[0116] In steps 1071-1072, before officially switching the power mode, the power source identification and engine start strategy pre-matching are completed. First, the pure electric no-engine working conditions are diverted to simplify the calculation. Then, for the working conditions that require engine start, a dedicated start scheme is customized based on the hardware status and fault signs. This can reduce redundant calculations in the controller, speed up the mode switching response, and ensure reliable engine start in the event of partial failure of the clutch or synchronizer. It avoids problems such as engine start failure, mode switching lag, and power output interruption, and provides complete and suitable preconditions for the smooth completion of the power transmission working mode switch.

[0117] Step 108: Switch the current power transmission working mode to the target power transmission working mode.

[0118] In this step, the vehicle controller, based on the determined target powertrain operating mode, coordinates the clutch, transmission synchronizer, engine, and front and rear motors to complete the powertrain mode switching. During the switching process, torque compensation is performed in real time to ensure that the vehicle's drive torque is continuous and without fluctuations. If the target powertrain operating mode includes the engine, the vehicle controller combines the transmission system fault flag information and synchronizer position to match the corresponding engine-specific start control strategy. When there is a partial fault in the direct drive mode, the front motor quick start, K1 slip start, and K2 slip start strategies can be selected to complete the engine ignition. If the target powertrain operating mode is consistent with the current powertrain operating mode, no component action is performed, and the existing transmission state continues to operate. For example, if the vehicle is currently operating in pure electric two-wheel drive mode, the target powertrain mode is direct drive mode, and the clutch K2 gear is faulty, then the K1 slip start strategy is used to ignite the engine. The clutch K1 gear is closed, and the odd-numbered shaft synchronizer is engaged in either the first gear (G1) or the third gear (G3) to complete the direct drive switch. If the vehicle is currently operating in pure electric four-wheel drive mode, and the target powertrain mode is series mode when the battery is low, then the even-numbered shaft synchronizer is placed in neutral, the clutch K2 gear is closed, and the front motor drives the engine into generator mode, with the vehicle driven only by the rear motor. If neither direct drive nor series drive is available, and the target powertrain mode is the same as the current mode, then the original pure electric driving state is maintained. This step adapts differentiated engine starting logic for different fault conditions. Even with partial transmission faults, the corresponding gear direct drive can still be activated, maximizing the vehicle's power output in fault scenarios. Multi-component collaborative control combined with a torque compensation mechanism eliminates mode switching jerks and optimizes ride comfort. When there is no switching requirement, the component states remain unchanged, reducing frequent clutch and synchronizer wear and extending the service life of the transmission system.

[0119] In steps 102-108, after recognizing the driver's high torque demand when the accelerator pedal opening exceeds a preset threshold, various hardware faults in the transmission system, mechanism position signals, and remaining battery power information are collected uniformly. This step can accurately identify high torque driving intentions such as overtaking and hill climbing, and only activate subsequent logic when there is a demand for high driving force, reducing the controller's computational load. At the same time, it fully collects core parameters of the transmission and battery, providing a comprehensive and reliable data foundation for mode recognition and fault determination, and proactively avoiding subsequent mode switching failures and battery power limitations. Based on the collected transmission system information, the real-time power transmission mode of the vehicle is identified, and graded fault flags are generated according to the fault status of components. Completely failed power modes are eliminated, and a set of usable modes where the hardware can operate normally is selected. This step can accurately distinguish between four types of transmission conditions: direct drive, pure electric four-wheel drive, pure electric two-wheel drive, and series drive, ensuring uninterrupted power during mode switching. At the same time, through two-level judgment of partial faults and complete faults, some usable driving force paths are retained, improving driving redundancy in fault conditions and preventing the loss of driving force due to the selection of a failure mode from the source. Subsequently, constrained by the remaining power battery charge, and prioritizing power according to the order of direct drive > pure electric four-wheel drive > pure electric two-wheel drive = series drive, the target power transmission mode is determined for three scenarios: high charge, low charge, and complete failure of the hydraulic drive mode. This step overcomes the shortcomings of existing solutions that force a switch to series drive after a direct drive failure, resulting in significant power attenuation. High charge prioritizes matching the maximum driving force mode to meet the driver's acceleration expectations; low charge activates series generator to protect the battery; and when all hydraulic drive modes fail, the current driving state is maintained, balancing power performance and power battery lifespan. Based on the selected target power transmission mode, the clutch, synchronizer, engine, and front and rear motors are coordinated to complete the switching. For target power transmission modes containing an engine, a dedicated engine starting strategy adapted to the fault state is matched. If the target power transmission mode is the same as the current mode, no switching action is performed. This step can activate the corresponding gear direct drive under partial transmission fault conditions to maximize power output in the fault scenario. During the switching process, torque compensation eliminates jerking and improves ride comfort. When there is no switching requirement, frequent operation of the transmission mechanism is reduced, reducing component wear and extending the service life of the transmission system. In summary, this application first accurately captures the driver's driving force requirements and completes full-domain status collection, then distinguishes the current operating conditions, eliminates faulty driving force paths, and combines battery power to select the target power transmission mode with the maximum driving force. Finally, it adapts to fault conditions to complete the smooth mode switch. In fault scenarios where direct drive mode components are abnormal and cannot be used, it no longer forces a switch to the weaker series mode. When the battery is sufficient, it prioritizes retaining the stronger pure electric four-wheel drive, effectively matching the driver's high torque expectations, while also taking into account the energy protection of the power battery and the durability of the transmission system, significantly improving the power performance and driving reliability of four-wheel drive hybrid vehicles under fault conditions and high torque conditions.

[0120] For example, in conjunction with the hybrid four-wheel drive vehicle control scheme of this application, a layered scenario determination is completed based on the direct drive mode fault flag, the power battery state of charge (SOC), the driver's torque demand, the current power transmission operating mode, and the series mode unavailable fault flag. The power output priority of the four power transmission operating modes is: direct drive mode > pure electric four-wheel drive mode > pure electric two-wheel drive mode = series mode. The vehicle controller (VCU) executes the following multiple scenario control logics: The current powertrain operating mode is pure electric two-wheel drive mode (EV rear-wheel drive): The vehicle controller recognizes that the driver's accelerator pedal opening is greater than a preset threshold, determining that there is a high torque demand; at the same time, the fault flag information for direct drive mode is an unavailable fault flag and the remaining battery power is greater than or equal to a preset battery power threshold. In order to match the driver's intention to output high torque, the vehicle controller requests to switch to pure electric four-wheel drive mode, does not generate an engine start command, and suppresses the engine start action.

[0121] The current powertrain operating mode is pure electric four-wheel drive mode: the vehicle controller detects that the driver's accelerator pedal opening is greater than a preset threshold, determining that there is a high torque demand; at the same time, the fault information for direct drive mode is an unavailable fault flag and the remaining battery power is greater than or equal to a preset battery power threshold. In order to continuously meet the driver's torque demand, the vehicle controller maintains the current pure electric four-wheel drive mode and does not generate an engine start command, thus suppressing the engine start action.

[0122] The current powertrain operating mode is pure electric two-wheel drive mode: the vehicle controller detects that the driver's accelerator pedal opening is greater than a preset threshold, determining that there is a high torque demand; at the same time, the fault flag information for direct drive mode is an unavailable fault flag, and the remaining battery power is less than a preset threshold. Because the direct drive mode is completely ineffective and cannot output maximum driving force, in order to balance the driver's torque demand and the power battery's power depletion protection, a layered judgment is made: if the fault flag information for series mode is empty (no fault in series mode, hardware circuit is intact), the vehicle controller requests to switch to series mode and issues an engine start control command; if the fault flag information for series mode is an unavailable fault flag, the vehicle controller requests to switch to pure electric four-wheel drive mode, suppresses engine start, and simultaneously reports a fault warning through the instrument panel: both direct drive mode and series mode are unavailable, and the power battery is at risk of deep power depletion.

[0123] The current powertrain operating mode is pure electric four-wheel drive mode: The vehicle controller detects that the driver's accelerator pedal opening is greater than the preset threshold, indicating a high torque demand; simultaneously, the fault flag information for direct drive mode is an unavailable fault flag, and the remaining battery charge is less than the preset threshold. Since direct drive mode is completely ineffective and cannot output maximum power, to balance the driver's torque demand and the battery's depletion protection, a tiered judgment is made: If the fault flag information for series mode is empty (no fault in series mode, hardware circuit intact), the vehicle controller requests a switch to series mode and issues an engine start control command; if the fault flag information for series mode is an unavailable fault flag, the vehicle controller maintains pure electric four-wheel drive operation, suppresses engine start, and simultaneously reports a fault warning via the instrument panel: both direct drive mode and series mode are unavailable, and the battery is at risk of deep depletion.

[0124] The engine has been ignited and started. The current power transmission mode is direct drive mode. The direct drive mode fault flag has been changed to an unavailable fault flag. The driver's required torque is greater than the torque threshold, and the remaining battery power is greater than or equal to the preset battery power threshold. The vehicle controller issues an engine shutdown command, requesting to switch to pure electric four-wheel drive mode, relying on the front and rear motors to output four-wheel drive power to match the driver's torque requirements.

[0125] The engine has been ignited and started. The current power transmission mode is series mode. The direct drive mode fault flag has been switched to an unavailable fault flag. The driver's required torque is greater than the torque threshold, and the remaining battery power is greater than or equal to the preset battery power threshold. The vehicle controller issues an engine shutdown command, requesting to switch to pure electric four-wheel drive mode, relying on the front and rear motors to output four-wheel drive power to match the driver's torque requirements.

[0126] The engine has been ignited and started. The current powertrain operating mode is direct drive mode. The direct drive mode fault flag has been changed to an unavailable fault flag. The driver's required torque is greater than the torque threshold, and the remaining battery power is less than the preset battery power threshold. Layered judgment is made: If the series mode fault flag is empty (the series circuit hardware is intact), the vehicle controller controls the powertrain system to switch to series mode operation, relying on the engine to drive the front motor to generate electricity to replenish the power battery; if the series mode fault flag is an unavailable fault flag, the vehicle controller issues an engine shutdown command and switches to pure electric four-wheel drive mode. At the same time, the instrument panel reports a fault reminder: both direct drive mode and series mode are unavailable, and the power battery is at risk of deep discharge.

[0127] The engine has been ignited and started. The current powertrain mode is series mode. The direct drive mode fault flag has been changed to an unavailable fault flag. The driver's required torque is greater than the torque threshold, and the remaining battery power is less than the preset battery power threshold. The following tiered judgment is made: If the series mode fault flag is empty (the series circuit hardware is intact), the vehicle controller maintains the current series mode operation and continues to generate electricity from the engine to maintain the battery power and supply the rear motor to drive the vehicle; if the series mode fault flag is an unavailable fault flag, the vehicle controller issues an engine shutdown command and switches to pure electric four-wheel drive mode. At the same time, the instrument panel reports a fault warning: both direct drive mode and series mode are unavailable, and the power battery is at risk of deep discharge.

[0128] It should be noted that the method in this embodiment can be executed by a single device, such as a computer or server. The method can also be applied in a distributed scenario, where multiple devices cooperate to complete the task. In such a distributed scenario, one of these devices may execute only one or more steps of the method in this embodiment, and the multiple devices will interact with each other to complete the method described.

[0129] It should be noted that the above description describes some embodiments of this application. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recorded in the claims can be performed in a different order than that shown in the above embodiments and still achieve the desired result. Furthermore, the processes depicted in the drawings do not necessarily require a specific or sequential order to achieve the desired result. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0130] Based on the same inventive concept, corresponding to any of the above embodiments, this application also provides a vehicle control device.

[0131] refer to Figure 6 The vehicle control device includes: The acquisition module 202 is configured to acquire the vehicle's transmission system status information and operating status information in response to the current accelerator pedal opening being greater than a preset opening threshold. The first determining module 204 is configured to determine the current power transmission working mode and the available power transmission working modes based on the transmission system status information. The second determining module 206 is configured to determine, based on the operating status information, a target power transmission operating mode that can provide the vehicle with a driving force greater than that provided by the current power transmission operating mode among the available power transmission operating modes. The switching module 208 is configured to switch the current power transmission operating mode to the target power transmission operating mode.

[0132] The first determining module 204 is further configured to determine the available power transmission operating mode based on the transmission system status information, including: Based on the transmission system status information, determine the fault flag information of the power transmission working mode; Based on the fault flag information of the power transmission operating mode, the available power transmission operating modes are determined.

[0133] The first determining module 204 is further configured such that the transmission system status information includes: clutch fault status, gearbox fault status, clutch in gear status, odd-numbered shaft synchronizer in gear status, even-numbered shaft synchronizer in gear status, front motor fault status, and rear motor fault status. The power transmission operating modes include: direct drive mode, pure electric four-wheel drive mode, pure electric two-wheel drive mode, and series mode; The step of determining the fault flag information of the power transmission operating mode based on the transmission system status information includes: In response to the clutch fault state being either an odd-numbered gear fault or an even-numbered gear fault, or the transmission fault state being that all gears of the transmission are damaged, the fault flag information for the direct drive mode is determined to be an unavailable fault flag. In response to the clutch fault state being an odd gear fault or the odd gear synchronizer being in an unavailable state, the fault flag information of the direct drive mode is determined to be a clutch odd gear fault flag. In response to the clutch fault state being an even-numbered gear fault or the even-numbered shaft synchronizer being in an unavailable gear state, the fault flag information for the direct drive mode is determined to be a clutch even-numbered gear fault flag. In response to the transmission failure status being all gears of the transmission damaged, the front motor failure status being damaged, or the rear motor failure status being damaged, the pure electric four-wheel drive mode is determined to be an unavailable fault flag; In response to the front motor being damaged and the rear motor being damaged, the pure electric two-wheel drive mode is determined to be an unavailable fault flag. In response to the clutch fault state being an even-numbered gear fault, the even-numbered shaft synchronizer being unavailable in its gear position, or the front motor being damaged, the fault flag information for the series mode is determined to be an unavailable fault flag.

[0134] The first determining module 204 is further configured to determine the available power transmission operating mode based on the fault flag information of the power transmission operating mode, including: The power transmission operating mode in which the fault flag information is the clutch odd gear fault flag, the clutch second gear fault flag, or the fault flag information is empty is designated as the available power transmission operating mode.

[0135] The second determining module 206, wherein the operating status information includes: remaining battery power; The step of determining, based on the operating status information, a target power transmission operating mode that can provide the vehicle with a driving force greater than that provided by the current power transmission operating mode among the available power transmission operating modes includes: In response to the remaining power being greater than or equal to a preset power threshold, the power transmission working mode with the maximum driving force among the available power transmission working modes is taken as the target power transmission working mode. In response to the remaining power being less than a preset power threshold, the available power transmission operating modes not including direct drive mode and the available power transmission operating modes including series mode, the series mode is taken as the target power transmission operating mode. In response to the remaining power being less than a preset power threshold and the available power transmission operating modes not including direct drive mode and series mode, the current power transmission operating mode is taken as the target power transmission operating mode.

[0136] The device further includes: a third determining module 210, configured to determine the power source in the target power transmission operating mode; and in response to the power source including an engine, to determine an engine start-up control strategy based on the transmission system status information, the fault flag information and the target power transmission operating mode.

[0137] The third determining module 210 is configured to determine the engine start-up control strategy based on the transmission system status information, the fault flag information, and the target power transmission operating mode, including: In response to the target power transmission operating mode being direct drive mode, an engine start control strategy is determined based on the fault flag information of the direct drive mode and the transmission system status information.

[0138] The third determining module 210 is configured such that the transmission system status information includes the position of the odd-numbered axis synchronizer and the position of the even-numbered axis synchronizer; The step of determining the engine start control strategy based on the fault flag information of the direct drive mode and the transmission system status information includes: In response to the fault flag information of the direct drive mode being a clutch odd gear fault flag, the odd shaft synchronizer being in neutral, and the even shaft synchronizer being in neutral, the engine start control strategy is determined to be a front motor-driven engine start strategy. In response to the fault flag information of the direct drive mode being a clutch odd-gear fault flag and the even-gear synchronizer being in an even-gear position, the engine start control strategy is determined to be a clutch even-gear slip start strategy. In response to the fault flag information of the direct drive mode being a clutch even-gear fault flag, the engine start control strategy is determined to be a clutch odd-gear slip start strategy.

[0139] The first determining module 204 is further configured such that the transmission system status information includes: clutch working status, gearbox gear position status, front motor status, front motor drive status, front motor working status, rear motor status, even-numbered shaft synchronizer position, and odd-numbered shaft synchronizer position. Determining the current power transmission operating mode based on the transmission system status information includes: In response to the engine being in a stopped state, the clutch being in a fully disengaged state, the front motor being in a stopped state, and the rear motor being in a started state, the current power transmission operating mode is determined to be a pure electric two-wheel drive mode. In response to the engine being in a stopped state, the clutch being in a fully disengaged state, the even-numbered shaft synchronizer being in an even-numbered gear position, the front motor being in an electric drive state, the front motor being in an output torque state, and the rear motor being in a start state, the current power transmission working mode is determined to be a pure electric four-wheel drive mode. In response to the engine being in the start state, the clutch being in the even-numbered shaft gear being closed, the even-numbered shaft synchronizer being in the neutral position, the odd-numbered shaft synchronizer being in the neutral position, the front motor being in engine drive mode, the front motor being in generator mode, and the rear motor being in the start state, the current power transmission mode is determined to be a series mode. In response to the engine being in the started state, the clutch being in the odd-numbered gear engaged state, the odd-numbered shaft synchronizer being in the odd-numbered gear position, the front motor being in the started state, and the rear motor being in the started state, or, In response to the engine being in the started state, the clutch being in the even-numbered gear engaged state, the even-numbered shaft synchronizer being in the even-numbered gear position, the front motor being in the started state, and the rear motor being in the started state, the current power transmission operating mode is determined to be direct drive mode.

[0140] For ease of description, the above devices are described in terms of function, divided into various modules. Of course, in implementing this application, the functions of each module can be implemented in one or more software and / or hardware.

[0141] The apparatus described above is used to implement a corresponding vehicle control method in any of the foregoing embodiments, and has the beneficial effects of the corresponding method embodiments, which will not be repeated here.

[0142] Based on the same inventive concept, corresponding to any of the above embodiments, this application also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement a vehicle control method as described in any of the above embodiments.

[0143] Figure 7 This embodiment illustrates a more specific hardware structure of an electronic device. The device may include a processor 1010, a memory 1020, an input / output interface 1030, a communication interface 1040, and a bus 1050. The processor 1010, memory 1020, input / output interface 1030, and communication interface 1040 are interconnected internally via the bus 1050.

[0144] The processor 1010 can be implemented using a general-purpose CPU (Central Processing Unit), microprocessor, application-specific integrated circuit (ASIC), or one or more integrated circuits, and is used to execute relevant programs to implement the technical solutions provided in the embodiments of this specification.

[0145] The memory 1020 can be implemented in the form of ROM (Read Only Memory), RAM (Random Access Memory), static storage device, dynamic storage device, etc. The memory 1020 can store the operating system and other applications. When the technical solutions provided in the embodiments of this specification are implemented by software or firmware, the relevant program code is stored in the memory 1020 and is called and executed by the processor 1010.

[0146] The input / output interface 1030 is used to connect input / output modules to realize information input and output. Input / output modules can be configured as components within the device (not shown in the figure) or externally connected to the device to provide corresponding functions. Input devices may include keyboards, mice, touchscreens, microphones, various sensors, etc., while output devices may include displays, speakers, vibrators, indicator lights, etc.

[0147] The communication interface 1040 is used to connect a communication module (not shown in the figure) to enable communication between this device and other devices. The communication module can communicate via wired means (such as USB, Ethernet cable, etc.) or wireless means (such as mobile network, WIFI, Bluetooth, etc.).

[0148] Bus 1050 includes a pathway for transmitting information between various components of the device, such as processor 1010, memory 1020, input / output interface 1030, and communication interface 1040.

[0149] It should be noted that although the above-described device only shows the processor 1010, memory 1020, input / output interface 1030, communication interface 1040, and bus 1050, in specific implementations, the device may also include other components necessary for normal operation. Furthermore, those skilled in the art will understand that the above-described device may only include the components necessary for implementing the embodiments of this specification, and not necessarily all the components shown in the figures.

[0150] The electronic devices described above are used to implement a corresponding vehicle control method in any of the foregoing embodiments and have the beneficial effects of the corresponding method embodiments, which will not be repeated here.

[0151] Based on the same inventive concept, corresponding to the methods of any of the above embodiments, this application also provides a non-transitory computer-readable storage medium that stores computer instructions for causing the computer to execute a vehicle control method as described in any of the above embodiments.

[0152] The computer-readable medium of this embodiment includes permanent and non-permanent, removable and non-removable media, and information storage can be implemented by any method or technology. Information can be computer-readable instructions, data structures, program modules, or other data. Examples of computer storage media include, but are not limited to, phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, CD-ROM, digital versatile optical disc (DVD) or other optical storage, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other non-transfer medium that can be used to store information accessible by a computing device.

[0153] The computer instructions stored in the storage medium of the above embodiments are used to cause the computer to execute a vehicle control method as described in any of the above embodiments, and have the beneficial effects of the corresponding method embodiments, which will not be repeated here.

[0154] Based on the same concept, corresponding to any of the above embodiments, this application also provides a computer program product, including computer program instructions, which, when run on a computer, cause the computer to perform the method described in any of the above embodiments, and have the beneficial effects of the corresponding method embodiments, which will not be repeated here.

[0155] Based on the same inventive concept, corresponding to any of the above embodiments, this application also provides a vehicle, including the electronic device or vehicle control device of the above embodiments, and executes a vehicle control method as described in any of the above embodiments through the electronic device or vehicle control device of the above embodiments, and has the beneficial effects of the corresponding method embodiments, which will not be repeated here.

[0156] It is understood that before using the technical solutions of the various embodiments in this application, users will be informed of the type, scope of use, and usage scenarios of the personal information involved in an appropriate manner, and user authorization will be obtained.

[0157] For example, upon receiving a user's active request, a prompt message is sent to the user to explicitly inform them that the requested operation will require the acquisition and use of the user's personal information. This allows the user to independently choose, based on the prompt message, whether to provide personal information to the software or hardware such as electronic devices, applications, servers, or storage media performing the operations described in this application.

[0158] As an optional but not limited implementation, in response to a user's active request, sending a prompt message to the user can be done via a pop-up window, where the prompt message can be presented in text format. Furthermore, the pop-up window can also include a selection control allowing the user to choose "agree" or "disagree" to provide personal information to the electronic device.

[0159] It is understood that the above notification and user authorization process is merely illustrative and does not limit the implementation of this application. Other methods that comply with relevant laws and regulations may also be applied to the implementation of this application.

[0160] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of this application is limited to these examples; under the concept of this application, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of different aspects of the embodiments of this application as described above, which are not provided in detail for the sake of brevity.

[0161] Additionally, to simplify the description and discussion, and to avoid obscuring the embodiments of this application, the well-known power / ground connections to integrated circuit (IC) chips and other components may or may not be shown in the provided drawings. Furthermore, the apparatus may be shown in block diagram form to avoid obscuring the embodiments of this application, and this also takes into account the fact that the details of the implementation of these block diagram apparatuses are highly dependent on the platform on which the embodiments of this application will be implemented (i.e., these details should be fully understood by those skilled in the art). While specific details (e.g., circuits) have been set forth to describe exemplary embodiments of this application, it will be apparent to those skilled in the art that the embodiments of this application can be implemented without these specific details or with variations thereof. Therefore, these descriptions should be considered illustrative rather than restrictive.

[0162] Although this application has been described in conjunction with specific embodiments thereof, many substitutions, modifications, and variations of these embodiments will be apparent to those skilled in the art from the foregoing description. For example, other memory architectures (e.g., dynamic RAM (DRAM)) may be used with the embodiments discussed.

[0163] The embodiments of this application are intended to cover all such substitutions, modifications, and variations that fall within the broad scope of the claims of this application. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the embodiments of this application should be included within the protection scope of this application.

Claims

1. A vehicle control method, wherein, The method includes: In response to the current accelerator pedal opening being greater than a preset opening threshold, the system acquires the vehicle's transmission system status information and operating status information. Based on the transmission system status information, determine the current power transmission operating mode and the available power transmission operating modes; Based on the operating status information, among the available power transmission operating modes, a target power transmission operating mode that can provide the vehicle with a driving force greater than that provided by the current power transmission operating mode is determined. Switch the current power transmission operating mode to the target power transmission operating mode.

2. The method according to claim 1, wherein, Based on the transmission system status information, the available power transmission operating modes are determined, including: Based on the transmission system status information, determine the fault flag information of the power transmission working mode; Based on the fault flag information of the power transmission operating mode, the available power transmission operating modes are determined.

3. The method according to claim 2, wherein, The transmission system status information includes: clutch fault status, gearbox fault status, clutch in gear status, odd-numbered shaft synchronizer in gear status, even-numbered shaft synchronizer in gear status, front motor fault status, and rear motor fault status. The power transmission operating modes include: direct drive mode, pure electric four-wheel drive mode, pure electric two-wheel drive mode, and series mode; The step of determining the fault flag information of the power transmission operating mode based on the transmission system status information includes: In response to the clutch fault state being either an odd-numbered gear fault or an even-numbered gear fault, or the transmission fault state being that all gears of the transmission are damaged, the fault flag information for the direct drive mode is determined to be an unavailable fault flag. In response to the clutch fault state being an odd gear fault or the odd gear synchronizer being in an unavailable state, the fault flag information of the direct drive mode is determined to be a clutch odd gear fault flag. In response to the clutch fault state being an even-numbered gear fault or the even-numbered shaft synchronizer being in an unavailable gear state, the fault flag information for the direct drive mode is determined to be a clutch even-numbered gear fault flag. In response to the transmission failure status being all gears of the transmission damaged, the front motor failure status being damaged, or the rear motor failure status being damaged, the pure electric four-wheel drive mode is determined to be an unavailable fault flag; In response to the front motor being damaged and the rear motor being damaged, the pure electric two-wheel drive mode is determined to be an unavailable fault flag. In response to the clutch fault state being an even-numbered gear fault, the even-numbered shaft synchronizer being unavailable in its gear position, or the front motor being damaged, the fault flag information for the series mode is determined to be an unavailable fault flag.

4. The method according to claim 3, wherein, The step of determining the available power transmission operating mode based on the fault flag information of the power transmission operating mode includes: The power transmission operating mode in which the fault flag information is the clutch odd gear fault flag, the clutch second gear fault flag, or the fault flag information is empty is designated as the available power transmission operating mode.

5. The method according to claim 4, wherein, The operating status information includes: remaining battery power; The step of determining, based on the operating status information, a target power transmission operating mode that can provide the vehicle with a driving force greater than that provided by the current power transmission operating mode among the available power transmission operating modes includes: In response to the remaining power being greater than or equal to a preset power threshold, the power transmission working mode with the maximum driving force among the available power transmission working modes is taken as the target power transmission working mode. In response to the remaining power being less than a preset power threshold, the available power transmission operating modes not including direct drive mode and the available power transmission operating modes including series mode, the series mode is taken as the target power transmission operating mode. In response to the remaining power being less than a preset power threshold and the available power transmission operating modes not including direct drive mode and series mode, the current power transmission operating mode is taken as the target power transmission operating mode.

6. The method according to claim 2, wherein, Before switching the current powertrain operating mode to the target powertrain operating mode, the following steps are also included: Determine the power source in the target power transmission operating mode; In response to the power source including an engine, an engine start-up control strategy is determined based on the transmission system status information, the fault flag information, and the target power transmission operating mode.

7. The method according to claim 6, wherein, Based on the transmission system status information, the fault indicator information, and the target power transmission operating mode, the engine start-up control strategy is determined, including: In response to the target power transmission operating mode being direct drive mode, an engine start control strategy is determined based on the fault flag information of the direct drive mode and the transmission system status information.

8. The method according to claim 7, wherein, The transmission system status information includes the positions of the odd-numbered axis synchronizers and the even-numbered axis synchronizers; The step of determining the engine start control strategy based on the fault flag information of the direct drive mode and the transmission system status information includes: In response to the fault flag information of the direct drive mode being a clutch odd gear fault flag, the odd shaft synchronizer being in neutral, and the even shaft synchronizer being in neutral, the engine start control strategy is determined to be a front motor-driven engine start strategy. In response to the fault flag information of the direct drive mode being a clutch odd gear fault flag and the even shaft synchronizer being in an even gear position, the engine start control strategy is determined to be a clutch even gear slip start strategy. In response to the fault flag information of the direct drive mode being a clutch even-gear fault flag, the engine start control strategy is determined to be a clutch odd-gear slip start strategy.

9. The method according to claim 1, wherein, The transmission system status information includes: clutch working status, gearbox gear position status, front motor status, front motor drive status, front motor working status, rear motor status, even-numbered shaft synchronizer position, and odd-numbered shaft synchronizer position. Determining the current power transmission operating mode based on the transmission system status information includes: In response to the engine being in a stopped state, the clutch being in a fully disengaged state, the front motor being in a stopped state, and the rear motor being in a started state, the current power transmission operating mode is determined to be a pure electric two-wheel drive mode. In response to the engine being in a stopped state, the clutch being in a fully disengaged state, the even-numbered shaft synchronizer being in an even-numbered gear position, the front motor being in an electric drive state, the front motor being in an output torque state, and the rear motor being in a start state, the current power transmission working mode is determined to be a pure electric four-wheel drive mode. In response to the engine being in the start state, the clutch being in the even-numbered shaft gear being closed, the even-numbered shaft synchronizer being in the neutral position, the odd-numbered shaft synchronizer being in the neutral position, the front motor being in engine drive mode, the front motor being in generator mode, and the rear motor being in the start state, the current power transmission mode is determined to be a series mode. In response to the engine being in the started state, the clutch being in the odd-numbered gear engaged state, the odd-numbered shaft synchronizer being in the odd-numbered gear position, the front motor being in the started state, and the rear motor being in the started state, or, In response to the engine being in the started state, the clutch being in the even-numbered gear engaged state, the even-numbered shaft synchronizer being in the even-numbered gear position, the front motor being in the started state, and the rear motor being in the started state, the current power transmission operating mode is determined to be direct drive mode.

10. A vehicle, wherein, The vehicles include: Memory, used to store executable program code; A processor for calling and running the executable program code from the memory, causing the vehicle to perform the method as described in any one of claims 1 to 9.

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