Method and apparatus for controlling switching between series / parallel driving mode of hybrid vehicle, vehicle, device, and medium

Abstract

A method and apparatus for controlling switching between series / parallel driving mode of a hybrid vehicle, which are used to solve the problems of being unable to complete series / parallel switching due to model selection not matching between an engine and a P1 generator, a P1 generator being in capable of speed adjustment, and a vehicle unexpectedly accelerating or decelerating. The method for controlling switching between series / parallel driving mode of a hybrid vehicle comprises: when a series / parallel switching request is received, reading relevant parameters of a vehicle and the current driving mode of the vehicle; preprocessing target torques of an engine, a generator, and a driving motor on the basis of the current driving mode of the vehicle and the relevant parameters of the vehicle; identifying a target driving mode of the vehicle on the basis of the received series / parallel switching request; and after the torque preprocessing is complete, according to the relevant parameters, the current driving mode, and the target driving mode of the vehicle, controlling switching between series / parallel driving mode of the vehicle.

Description

A hybrid vehicle series-parallel drive mode switching control method, device, vehicle, equipment and medium Technical Field

[0001] The present application relates to the field of hybrid vehicle control, and specifically to a method, device, vehicle, equipment, and medium for controlling series-parallel drive mode switching of a hybrid vehicle. Background Art

[0002] In recent years, faced with the oil crisis and increasingly stringent fuel consumption regulations, hybrid vehicles have become a research hotspot for major manufacturers. Among these, the P13 configuration, a relatively easy-to-implement hybrid configuration, has attracted increasing research attention. As shown in Figure 1, at low vehicle speeds, the K3 clutch is disengaged, and the vehicle operates in series drive mode. The engine does not directly drive the vehicle, generating power through the P1 generator. The P3 drive motor draws power from the power battery or the P1 generator to drive the vehicle. At medium and high speeds, the K3 clutch is engaged, and the vehicle operates in parallel drive mode. The engine directly drives the vehicle, while the P3 motor assists in adjusting the engine operating point to maintain a low fuel consumption range. Based on vehicle economy and power requirements, the optimal drive mode is selected according to vehicle status. The typical series-parallel drive mode switching process requires coordination of the speed and torque of the engine, P1 generator, and P3 drive motor, as well as control of the K3 clutch. This is relatively complex and has attracted increasing research.

[0003] CN113335262A - A control method, vehicle, and storage medium for hybrid vehicle drive mode switching. This patent application provides a control method for switching from series to parallel, including adjusting the engine torque to the target engine torque in the parallel drive mode, adjusting the engine speed to the same speed as the drive motor speed in the series drive mode, engaging the clutch, reducing the generator torque to zero, and simultaneously reducing the generator torque by the same amount. The control method for switching from parallel to series includes increasing the negative torque of the generator to absorb the engine torque to adjust the drive motor torque to the target torque in the series drive mode, disengaging the clutch, and adjusting the engine torque and speed to the target torque and target speed in the series drive mode.

[0004] Although the above scheme provides a basic control method for the series-parallel switching process, it obviously has the following problems: 1. It does not take into account the matching of engine and generator selection. For example, the target torque of the engine in parallel drive mode exceeds the maximum power generation torque of the P1 generator. At the beginning of series-to-parallel switching, the engine target torque cannot be adjusted to the engine target torque in the parallel drive mode; at the beginning of parallel-to-series switching, the P1 generator cannot absorb the negative torque of the engine in the parallel drive mode, resulting in the inability to complete the series-to-parallel switching. 2. When the P1 generator is generating electricity at its maximum capacity, it will not be able to adjust the speed, nor will it be able to complete the series-to-parallel switching. 3. The torque transmission characteristics of clutch closing and disengagement are not considered, resulting in unexpected acceleration and deceleration of the vehicle.

[0005] Summary of the Invention

[0006] The present application provides a series-parallel drive mode switching control method, apparatus, vehicle, equipment and medium for a hybrid vehicle, which are used to solve the problems of inability to complete series-parallel switching due to mismatch between engine and P1 generator selection, inability to adjust the speed of the P1 generator, and unexpected acceleration and deceleration of the vehicle during the series-parallel switching process.

[0007] The technical solution of this application is:

[0008] The present application provides a series-parallel drive mode switching control method for a hybrid vehicle. The hybrid system of the hybrid vehicle includes at least: a power battery, an engine, a drive motor, a generator, and a clutch. The engine can be connected to or disconnected from the wheel end through the clutch. The drive motor is directly connected to the wheel end. The drive motor is connected to the power battery, the generator is connected to the engine, and the generator is connected to the power battery and / or the drive motor. The method includes:

[0009] When receiving a series-parallel switching request, read relevant parameters of the vehicle and the current driving mode of the vehicle;

[0010] Preprocessing the target torque of the engine, generator, and drive motor based on the vehicle's current driving mode and relevant vehicle parameters;

[0011] identifying a target driving mode of the vehicle based on the received series-parallel switching request;

[0012] After the torque preprocessing is completed, the series-parallel drive mode switching control of the vehicle is performed according to the relevant parameters of the vehicle, the current drive mode and the target drive mode.

[0013] Optionally, the relevant parameters of the vehicle include: vehicle speed, accelerator pedal opening, actual engine torque, actual generator torque, current engine target torque, current generator target torque, current drive motor target torque, maximum generator torque, maximum engine torque, engine-to-generator speed ratio, generator-to-drive motor speed ratio, drive motor-to-wheel speed ratio, and clutch oil pressure. Based on the current driving mode of the vehicle and the relevant parameters of the vehicle, the step of preprocessing the target torques of the engine, the generator, and the drive motor includes:

[0014] Determine the maximum available torque of the engine during series-parallel switching based on the maximum generating torque of the generator and the maximum torque of the engine;

[0015] Determining the target engine torque and the target generator torque during series-parallel switching based on the current driving mode of the vehicle, the maximum available engine torque during series-parallel switching, and the current target engine torque;

[0016] Based on the current driving mode of the vehicle, the engine target torque and the generator target torque during series-parallel switching, updating the current engine target torque value and the current generator target torque value;

[0017] Based on the driver's required torque, the drive motor to wheel speed ratio, the engine to generator speed ratio, the generator to drive motor speed ratio, the actual engine torque, the actual generator torque, and the clutch oil pressure, the drive motor target torque is determined during series-parallel switching, and the current drive motor target torque value is updated;

[0018] The driver's required torque is obtained by looking up the table based on the vehicle speed and the accelerator pedal opening.

[0019] Optionally, the absolute value of the maximum power generation torque of the generator and the smaller value of the maximum torque of the engine are first determined, and then the smaller value is added to the first preset torque value to determine the maximum available torque of the engine during the series-parallel drive mode switching control;

[0020] Determining the smaller value of the maximum available engine torque during series-parallel switching and the current engine target torque as the engine target torque during series-parallel drive mode switching control;

[0021] If the current driving mode of the vehicle is the parallel driving mode, the target torque of the generator during series-parallel switching is determined to be 0;

[0022] If the current driving mode of the vehicle is the series driving mode, the target torque of the generator during series-parallel switching is determined to be the actual torque of the generator.

[0023] Optionally, the target drive mode includes a parallel drive mode, and the relevant parameters of the vehicle include: actual engine torque, actual generator speed, actual generator torque, actual clutch oil pressure, current generator target speed, and engine target torque, generator target torque, drive motor target torque, and generator target speed output by the vehicle's torque distribution module in the parallel drive mode. If the target drive mode is the parallel drive mode, the steps of performing series-parallel drive mode switching control of the vehicle according to the relevant parameters of the vehicle, the current drive mode, and the target drive mode include:

[0024] Entering the generator speed synchronization stage: setting the actual generator torque as the generator target torque, and gradually adjusting the current generator target speed to the generator target synchronous speed;

[0025] In the generator speed synchronization stage, if the absolute value of the difference between the generator synchronization target speed and the generator actual speed is less than the first preset speed value, the clutch closing stage is entered: clutch closing control is performed;

[0026] After completing the clutch closing control, if the actual clutch oil pressure is greater than or equal to the first preset oil pressure, the torque recovery stage is entered: the generator control mode is adjusted from speed control to torque control, and the values ​​of the engine target torque, generator target torque, drive motor target torque and generator target speed during series-parallel switching are adjusted to the engine target torque, generator target torque, drive motor target torque and generator target speed output by the vehicle's torque distribution module in parallel drive mode.

[0027] Optionally, the relevant parameters of the vehicle include: vehicle speed, generator-to-wheel end speed ratio, and tire diameter; wherein the generator target synchronous speed is calculated by the formula:

[0028] Calculated, where VehSpd is the vehicle speed, P1Ratio is the generator to wheel speed ratio, and D is the tire diameter.

[0029] Optionally, the target drive mode includes a series drive mode, and the relevant parameters of the vehicle include: actual engine torque, actual generator torque, actual generator speed, actual clutch oil pressure, engine-to-generator speed ratio, and target engine torque, generator target torque, drive motor target torque, and generator target speed output by the vehicle's torque distribution module in the series drive mode. If the target drive mode is the series drive mode, the steps of performing series-parallel drive mode switching control of the vehicle according to the relevant vehicle parameters, the current drive mode, and the target drive mode include:

[0030] Entering the torque exchange phase: gradually increasing the generator target torque from the generator target torque during series-parallel switching to the negative value of the engine target torque during series-parallel switching multiplied by the engine-to-generator speed ratio, while adjusting the drive motor target torque to follow the changes and meet the driver's torque demand; setting the actual generator speed to the generator target speed during series-parallel switching;

[0031] If the absolute value of the sum of the actual torque of the engine and the actual torque of the generator is less than or equal to the sixth preset torque value during the torque exchange phase, the clutch disconnection phase is entered: clutch disconnection control is performed;

[0032] After completing the clutch disconnection control, if the actual clutch oil pressure is less than or equal to the second preset oil pressure, the speed and torque recovery stage is entered: the generator mode control is adjusted from torque control to speed control, and the engine target torque, generator target torque, drive motor target torque, and generator target speed values ​​during series-parallel switching are adjusted to the engine target torque, generator target torque, drive motor target torque, and generator target speed output by the vehicle's torque distribution module in the series drive mode.

[0033] Optionally, after completing the numerical adjustment of the engine target torque, the generator target torque, the drive motor target torque, and the generator target speed, the method further includes:

[0034] If the absolute value of the difference between the engine target torque and the actual engine torque output by the vehicle's torque distribution module in parallel drive mode is less than or equal to the second preset torque value, the absolute value of the difference between the generator target torque and the actual generator torque output by the vehicle's torque distribution module in parallel drive mode is less than or equal to the third preset torque value, and the absolute value of the difference between the drive motor target torque and the actual drive motor torque output by the vehicle's torque distribution module in parallel drive mode is less than or equal to the fourth preset torque value, it is determined that the vehicle has completed switching from series drive mode to parallel drive mode.

[0035] Optionally, the target torque P3TqReq of the driving motor during series-parallel switching is calculated by the formula:

[0036] P3TqReq={DrvTqReq / P3Ratio-(EngTqAct*EngP1Ratio+P1TqAct) / abs(EngTqAct*EngP1Ratio+P1TqAct)*min[abs(EngTqAct*EngP1Ratio+P1TqAct),CluCarryTq]*P1P3Ratio}

[0037] Calculated, DrvTqReq is the driver's required torque, which is obtained by looking up the table based on the vehicle speed and accelerator pedal opening; P3Ratio is the speed ratio from the drive motor to the wheel end, EngTqAct is the actual engine torque, EngP1Ratio is the speed ratio from the engine to the generator, P1TqAct is the actual torque of the generator, P1P3Ratio is the speed ratio from the generator to the drive motor, and CluCarryTq is the clutch's transmittable torque, which is obtained by looking up the clutch oil pressure characteristic curve that represents the correlation between the actual clutch oil pressure and the clutch's transmittable torque CluCarryTq.

[0038] Optionally, after adjusting the target torque of the engine, the target torque of the generator, the target torque of the drive motor, and the target speed of the generator, the method further includes:

[0039] If the absolute value of the difference between the engine target torque and the actual engine torque output by the vehicle's torque distribution module in the series drive mode is less than or equal to the eighth preset torque value, the absolute value of the difference between the generator target speed and the actual generator speed output by the vehicle's torque distribution module in the series drive mode is less than or equal to the eighth preset speed value, and the absolute value of the difference between the drive motor target torque and the actual drive motor torque output by the vehicle's torque distribution module in the series drive mode is less than or equal to the ninth preset torque value, it is determined that the vehicle has completed switching from the parallel drive mode to the series drive mode.

[0040] The present application also provides a series-parallel drive mode switching control device for a hybrid vehicle, wherein the hybrid system of the hybrid vehicle comprises at least: a power battery, an engine, a drive motor, a generator, and a clutch, wherein the engine can be connected to or disconnected from the wheel end via the clutch, the drive motor is directly connected to the wheel end, the drive motor is connected to the power battery, the generator is connected to the engine, and the generator is connected to the power battery and / or the drive motor, and the device comprises:

[0041] A parameter reading module is used to read relevant parameters of the vehicle and the current driving mode of the vehicle when receiving a series-parallel switching request;

[0042] A torque preprocessing module is used to preprocess the target torque of the engine, generator and drive motor based on the current driving mode of the vehicle and relevant parameters of the vehicle;

[0043] a target driving mode identification module, configured to identify a target driving mode of the vehicle based on the received series-parallel switching request;

[0044] The driving mode switching control module is used to control the series-parallel driving mode switching of the vehicle according to the relevant parameters of the vehicle, the current driving mode and the target driving mode after completing the torque preprocessing.

[0045] Optionally, the vehicle-related parameters include: vehicle speed, accelerator pedal opening, actual engine torque, actual generator torque, current engine target torque, current generator target torque, current drive motor target torque, maximum generator torque, maximum engine torque, engine-to-generator speed ratio, generator-to-drive motor speed ratio, drive motor-to-wheel-end speed ratio, and clutch oil pressure. The torque preprocessing module includes:

[0046] an engine maximum available torque determination unit, configured to determine the engine maximum available torque during series-parallel switching based on the generator maximum generating torque and the engine maximum torque;

[0047] an engine and generator target torque determination unit, configured to determine the engine target torque and the generator target torque during series-parallel switching based on the vehicle's current driving mode, the maximum available engine torque during series-parallel switching, and the current engine target torque;

[0048] an engine and generator target torque value updating unit, configured to update a current engine target torque value and a current generator target torque value based on a current driving mode of the vehicle, and the engine target torque and the generator target torque during series-parallel switching;

[0049] a drive motor target torque determination and value update unit, configured to determine the drive motor target torque during series-parallel switching based on the driver's required torque, the drive motor-to-wheel speed ratio, the engine-to-generator speed ratio, the generator-to-drive motor speed ratio, the actual engine torque, the actual generator torque, and the clutch oil pressure, and to update the current drive motor target torque value;

[0050] The driver's required torque is obtained by looking up the table based on the vehicle speed and the accelerator pedal opening.

[0051] Optionally, the target driving mode includes a parallel driving mode, and the relevant parameters of the vehicle include: actual engine torque, actual generator speed, actual generator torque, actual clutch oil pressure, current generator target speed, and engine target torque, generator target torque, drive motor target torque, and generator target speed output by the vehicle's torque distribution module in the parallel driving mode. If the target driving mode is the parallel driving mode, the driving mode switching control module includes:

[0052] The generator speed synchronization unit is used to enter the generator speed synchronization stage: set the actual generator torque to the generator target torque, and gradually adjust the current generator target speed to the generator target synchronous speed;

[0053] a clutch closing unit, configured to, during the generator speed synchronization phase, enter a clutch closing phase if the absolute value of the difference between the generator synchronization target speed and the generator actual speed is less than a first preset speed value: perform clutch closing control;

[0054] The torque recovery unit is used to enter the torque recovery stage if the actual clutch oil pressure is greater than or equal to the first preset oil pressure after completing the clutch closing control: the generator control mode is adjusted from speed control to torque control, and the values ​​of the engine target torque, generator target torque, drive motor target torque and generator target speed during series-parallel switching are adjusted to the engine target torque, generator target torque, drive motor target torque and generator target speed output by the vehicle's torque distribution module in the parallel drive mode.

[0055] Optionally, the target drive mode includes a series drive mode, and the relevant parameters of the vehicle include: actual engine torque, actual generator torque, actual generator speed, actual clutch oil pressure, engine-to-generator speed ratio, and engine target torque, generator target torque, drive motor target torque, and generator target speed output by the vehicle's torque distribution module in the series drive mode. If the target drive mode is the series drive mode, the drive mode switching control module includes: a torque exchange unit, configured to enter a torque exchange phase: gradually increase the generator target torque from the generator target torque at the time of series-parallel switching to the negative value of the engine target torque at the time of series-parallel switching multiplied by the engine-to-generator speed ratio, and at the same time adjust the drive motor target torque to follow the change to meet the driver's required torque; set the actual generator speed to the generator target speed at the time of series-parallel switching;

[0056] A clutch disconnection unit is configured to, if in the torque exchange phase, the absolute value of the sum of the actual torque of the engine and the actual torque of the generator is less than or equal to a sixth preset torque value, enter a clutch disconnection phase: and perform clutch disconnection control;

[0057] The speed torque recovery unit is used to enter the speed torque recovery stage if the actual clutch oil pressure is less than or equal to the second preset oil pressure after completing the clutch disconnection control: the generator mode control is adjusted from torque control to speed control, and the values ​​of the engine target torque, generator target torque, drive motor target torque, and generator target speed during series-parallel switching are adjusted to the engine target torque, generator target torque, drive motor target torque, and generator target speed output by the vehicle's torque distribution module in the series drive mode.

[0058] The present application also provides a vehicle, comprising the above-mentioned series-parallel drive mode switching control device for a hybrid vehicle.

[0059] The present application also provides a control device, including a processor, a memory, and a program or instruction stored in the memory and executable on the processor. When the program or instruction is executed by the processor, the steps of the series-parallel drive mode switching control method for a hybrid vehicle as described above are implemented.

[0060] The present application also provides a readable storage medium, which stores a program or instruction. When the program or instruction is executed by a processor, the steps of the series-parallel drive mode switching control method of the hybrid vehicle are implemented as described above.

[0061] The beneficial effects of this application are:

[0062] When a series-parallel switching request is received, to avoid the problem of being unable to update to the target torque or speed of the target drive mode and unable to adjust the speed due to engine and generator selection mismatch, especially when the vehicle is operating in parallel drive mode, where the engine target torque may exceed the engine and generator coupling boundary capacity, this solution proposes to pre-process the engine and generator target torques before the series-parallel switching is performed. By calculating the engine and generator coupling boundary and reserving torque for speed adjustment at the coupling boundary, the engine and generator target torques are constrained by the coupling boundary after processing as the target torque during the series-parallel switching process. At the same time, the drive motor target torque is also adaptively adjusted to ensure the driver's torque demand. This solution completely solves the problem of being unable to update to the target torque of the target drive mode and unable to adjust the speed during the series-parallel switching process. In addition, during the clutch charging and discharging process, the power source target torque calculation incorporates the clutch torque transmission characteristics, making the power source target torque calculation more reasonable and realistic, and avoiding the problem of unintended vehicle acceleration and deceleration caused by ignoring the actual power source torque output to the vehicle during the clutch charging and discharging process. BRIEF DESCRIPTION OF THE DRAWINGS

[0063] FIG1 is a schematic diagram of the P13 configuration in this embodiment;

[0064] FIG2 is a flow chart of the method in this embodiment;

[0065] FIG3 is a structural block diagram of the device in this embodiment. DETAILED DESCRIPTION

[0066] The following will describe the embodiments of the present application with reference to the accompanying drawings and preferred embodiments. Those skilled in the art can easily understand the other advantages and effects of the present application from the contents disclosed in this specification. The present application can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present application. It should be understood that the preferred embodiments are only for the purpose of illustrating the present application and are not intended to limit the scope of protection of the present application.

[0067] It should be noted that the illustrations provided in the following embodiments are only schematic illustrations of the basic concept of the present application. Therefore, the illustrations only show components related to the present application and are not drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component can be changed at will, and the component layout type may also be more complicated.

[0068] 1 , the series-parallel drive mode switching control method for the hybrid vehicle provided in this embodiment is mainly applicable to hybrid vehicles with the following characteristics: the hybrid vehicle at least includes: a power battery, an engine, a drive motor, a generator, and a clutch. The engine can be connected to or disconnected from the wheel end through the clutch, the drive motor is directly connected to the wheel end, the drive motor is connected to the power battery, the generator is connected to the engine, and the generator is connected to the power battery and / or the drive motor. Specifically, for the hybrid vehicle with the P13 configuration in FIG1 , the generator refers to the P1 motor in FIG1 , the drive motor refers to the P3 motor in FIG1 , and the clutch refers to the K3 clutch in FIG1 . For the hybrid vehicle with the P13 configuration, the P1 generator is connected to both the power battery and the P3 drive motor. In this embodiment, the above-mentioned hybrid vehicle can also be applied to vehicles with other configurations, as long as the vehicles with these configurations have the above-mentioned specific characteristics.

[0069] As shown in FIG2 , the series-parallel driving mode switching control method of the hybrid vehicle provided in this embodiment specifically includes:

[0070] Step S1: upon receiving a series-parallel switching request output by a series-parallel timing determination function, reading relevant parameters of the vehicle and the current driving mode of the vehicle;

[0071] Step S2: Based on the relevant parameters of the vehicle and the current driving mode of the vehicle, enter torque preprocessing. After completing step S2, enter step S3 or S4;

[0072] Step S3: If the series-parallel switching request is a series-to-parallel switching request, entering series-to-parallel switching control; specifically, based on the received series-parallel switching request, identifying that the target driving mode of the vehicle is the parallel driving mode; after completing torque preprocessing, controlling the vehicle to switch from the series driving mode to the parallel driving mode based on relevant vehicle parameters, the current driving mode, and the target driving mode;

[0073] Step S4: If the series-parallel switching request is a parallel-to-series switching request, enter parallel-to-series control; specifically, based on the received series-parallel switching request, identify the target drive mode of the vehicle as the series drive mode; after completing torque preprocessing, control the vehicle to switch from the parallel drive mode to the series drive mode according to relevant vehicle parameters, the current drive mode, and the target drive mode.

[0074] In this embodiment, the series-parallel switching request is specifically a series-to-parallel switching request or a parallel-to-series switching request, and the output of the request is implemented by the existing technology.

[0075] In this embodiment, for the series-parallel switching timing determination function in step S1, specifically, the series-parallel switching request can be output by comprehensively considering the economy and power of the vehicle through the vehicle state and the driver's needs. The series-parallel switching request can be a request obtained using existing technology (such as the method introduced in the background technology). The specific information carried in the series-parallel switching request signal can be a parallel switching request when the vehicle needs to enter the series drive mode from the parallel drive mode or a series switching request when the vehicle needs to enter the parallel drive mode from the series drive mode.

[0076] In this embodiment, the torque preprocessing process in step S2 can be specifically understood as: determining the maximum available engine torque during series-parallel switching based on the maximum generator torque and the maximum engine torque; determining the engine target torque and the generator target torque during series-parallel switching based on the vehicle's current driving mode, the maximum available engine torque during series-parallel switching, and the current engine target torque; updating the current engine target torque and the current generator target torque based on the vehicle's current driving mode, the engine target torque and the generator target torque during series-parallel switching; determining the drive motor target torque during series-parallel switching and updating the current drive motor target torque based on the driver's required torque, the drive motor-to-wheel speed ratio, the engine-to-generator speed ratio, the generator-to-drive motor speed ratio, the engine actual torque, the generator actual torque, and the clutch oil pressure. The above-mentioned vehicle-related parameters include: vehicle speed, accelerator pedal opening, engine actual torque, generator actual torque, current engine target torque, current generator target torque, current drive motor target torque, generator maximum torque, engine maximum torque, engine-to-drive motor speed ratio, generator-to-drive motor speed ratio, drive motor-to-wheel speed ratio, and clutch oil pressure.

[0077] In this embodiment, EngTqMaxSPC is the maximum available torque of the engine during series-parallel switching, and its calculation formula is as follows:

[0078] EngTqMaxSPC=min([EngTqMax,abs(P1GenTqMax)])-TBD1

[0079] Wherein, EngTqMax is the maximum torque of the engine, P1GenTqMax is the maximum power generation torque of the generator (in this embodiment, it is the maximum power generation torque of the P1 generator of the P13 configuration), and TBD1 is a calibration value.

[0080] Furthermore, EngTqReqSPC is the target engine torque during series-parallel switching, and the specific calculation formula is as follows:

[0081] EngTqReqSPC=min(EngTqReq,EngTqMaxSPC)

[0082] Among them, EngTqReq is the current engine target torque.

[0083] The target torque P3TqReq of the drive motor during series-parallel switching is calculated by the formula:

[0084] P3TqReq={DrvTqReq / P3Ratio-(EngTqAct*EngP1Ratio+P1TqAct) / abs(EngTqAct*EngP1Ratio+P1TqAct)*min[abs(EngTqAct*EngP1Ratio+P1TqAct),CluCarryTq]*P1P3Ratio}

[0085] Calculated, DrvTqReq is the driver's required torque, which is obtained by looking up the table based on the vehicle speed and accelerator pedal opening; P3Ratio is the speed ratio from the drive motor to the wheel end, EngTqAct is the actual engine torque, EngP1Ratio is the speed ratio from the engine to the generator, P1TqAct is the actual torque of the generator, P1P3Ratio is the speed ratio from the generator to the drive motor, and CluCarryTq is the clutch's transmittable torque, which is obtained by looking up the clutch oil pressure characteristic curve that represents the correlation between the actual clutch oil pressure and the clutch's transmittable torque CluCarryTq.

[0086] In step S3 , based on the received series-parallel switching request, it is first identified that the target driving mode of the vehicle is the parallel driving mode.

[0087] The specific process of performing the series-parallel drive mode switching control is as follows: performing the series-parallel drive mode switching control of the vehicle according to the relevant parameters of the vehicle, the current drive mode and the target drive mode.

[0088] As shown in FIG2 , step S3 specifically includes the following steps:

[0089] (S301) Speed ​​synchronization stage. Specifically, the target engine torque, generator target torque, and drive motor target torque during series-parallel switching are calculated according to the method described in step S2. The generator target speed is gradually adjusted from the current generator target speed to the generator target synchronous speed during series-parallel switching. The generator target synchronous speed during series-parallel switching is calculated based on the vehicle speed, the generator-to-wheel speed ratio, and the tire diameter. The adjustment process should ensure smooth target speed adjustment, and no specific requirements are imposed on the implementation method, such as slope restrictions.

[0090] If the following formula is satisfied, then proceed to step (302):

[0091] |P1SpsReqsyn-P1SpdAct|≤TBD2

[0092] Among them, P1SpsReqsyn is the generator synchronous target speed during series-parallel switching (in this embodiment, it is the P1 generator target synchronous speed of the P13 configuration), P1SpdAct is the actual speed of the P1 motor, and TBD2 is a calibration value (first preset speed value), such as 50rpm.

[0093] Furthermore, for the target synchronous speed P1SpdReqsyn of the generator during series-parallel switching, its calculation formula is as follows:

[0094] Among them, VehSpd is the vehicle speed, P1Ratio is the speed ratio from the generator to the wheel end, and D is the tire diameter.

[0095] (S302) Clutch closing stage, specifically, the clutch solenoid valve is opened and the hydraulic module is filled with oil to complete clutch closing.

[0096] The target torque of the engine and the target torque of the generator during series-parallel switching are obtained by the calculation method described in step S2, and the target speed of the generator during series-parallel switching is obtained by the calculation method described in step S301.

[0097] If the following formula is satisfied, proceed to step (S303):

[0098] CluPrsAct≥TBD3

[0099] Among them, CluPrsAct is the actual oil pressure of the clutch (obtained by the transmission control unit), and TBD3 is a calibration value (first preset oil pressure), such as 10 bar.

[0100] (S303) Torque recovery stage, specifically, the generator control mode is adjusted from speed control to torque control, and the engine target torque and generator target torque during series-parallel switching calculated according to the method described in step S2, the drive motor target torque during series-parallel switching calculated according to the method described in step S302, and the generator target speed during series-parallel switching calculated according to the method described in step S301 are respectively adjusted to the target torque value and generator target speed value outputted by the vehicle's torque distribution module in the parallel drive mode. The target torque should be smooth during the adjustment process, and there are no specific requirements for the implementation method, such as using slope limitation and other methods.

[0101] Furthermore, if the following formulas (a), (b), and (c) are satisfied at the same time, the series-to-parallel switching process ends.

[0102] |EngTqReqPHEV-EngTqAct|≤TBD4 (a)

[0103] |P1TqReqPHEV-P1TqAct|≤TBD5 (b)

[0104] |P3TqReqPHEV-P3TqAct|≤TBD6 (c)

[0105] EngTqReqPHEV, P1TqReqPHEV, and P3TqReqPHEV are respectively the engine target torque, generator target torque (in this embodiment, the P1 generator target torque of the P13 configuration), and drive motor target torque (in this embodiment, the P3 drive motor target torque of the P13 configuration) output by the torque distribution function in the parallel drive mode; EngTqAct, P1TqAct, and P3TqAct are respectively the engine actual torque, generator actual torque (in this embodiment, the P1 generator actual torque of the P13 configuration), and drive motor actual torque (in this embodiment, the P13 drive motor actual torque of the P13 configuration); TBD4 is a calibration value (corresponding to the second preset torque value), such as 5Nm, TBD5 is a calibration value (corresponding to the third preset torque value), such as 5Nm, and TBD6 is a calibration value (corresponding to the fourth preset torque value), such as 5Nm.

[0106] That is to say, if the absolute value of the difference between the engine target torque and the actual engine torque output by the vehicle's torque distribution module in the parallel drive mode is less than or equal to the second preset torque value, the absolute value of the difference between the generator target torque and the actual generator torque output by the vehicle's torque distribution module in the parallel drive mode is less than or equal to the third preset torque value, and the absolute value of the difference between the drive motor target torque and the actual drive motor torque output by the vehicle's torque distribution module in the parallel drive mode is less than or equal to the fourth preset torque value, it is determined that the vehicle is switched from the series drive mode to the parallel drive mode, and then controlled according to the target torques allocated to the engine, generator and drive motor respectively in the parallel drive mode.

[0107] To switch modules in parallel or in series, the specific steps are as follows:

[0108] (S401) Torque exchange phase. Specifically, the current engine target torque is gradually adjusted to the engine target torque during series-parallel switching. Meanwhile, the generator target torque is gradually increased from the generator target torque during series-parallel switching to the negative value of the engine target torque during series-parallel switching multiplied by the engine-to-generator speed ratio. Simultaneously, the drive motor target torque is adjusted to follow the change to meet the driver's torque demand, and the actual generator speed is set to the generator target speed during series-parallel switching.

[0109] Among them, the calculation formula of the generator target torque P1TqReq during series-parallel switching is:

[0110] P1TqReq=-EngTqReq*EngP1Ratio

[0111] EngTqReq is the target torque of the engine during series-parallel switching calculated by the method described in step S2, and EngP1Ratio is the speed ratio from the engine to the generator end.

[0112] The target torque of the drive motor during series-parallel switching is calculated according to the following method. At this time, the target torque of the drive motor during series-parallel switching, P3TqReq, is obtained by the formula:

[0113] P3TqReq={DrvTqReq / P3Ratio-(EngTqAct*EngP1Ratio+P1TqAct) / abs(EngTqAct*EngP1Ratio+P1TqAct)*min[abs(EngTqAct*EngP1Ratio+P1TqAct),CluCarryTq]*P1P3Ratio}

[0114] Calculated, DrvTqReq is the driver's required torque, obtained by looking up the table based on vehicle speed and accelerator pedal opening, P3Ratio is the speed ratio from the drive motor to the wheel end, EngTqAct is the actual engine torque, EngP1Ratio is the speed ratio from the engine to the generator, P1TqAct is the actual torque of the generator, P1P3Ratio is the speed ratio from the generator to the drive motor, and CluCarryTq is the clutch's transmittable torque. The clutch's transmittable torque CluCarryTq is obtained by looking up the clutch oil pressure characteristic curve that represents the correlation between the actual clutch oil pressure and the clutch's transmittable torque CluCarryTq.

[0115] If the following formula is satisfied, proceed to step (S402)

[0116] |EngTqAct+P1TqAct|≤TBD8

[0117] EngTqAct is the actual torque of the engine; P1TqAct is the actual torque of the generator;

[0118] Wherein, TBD8 is a calibration value (sixth preset torque value), such as 5 Nm.

[0119] (S402) Clutch disconnection stage. Specifically, the clutch solenoid valve is closed and the hydraulic module releases the oil pressure to complete the clutch disconnection;

[0120] The target torque of the engine, the target torque of the generator, the target torque of the drive motor, and the target speed of the generator are obtained by the calculation method described in step S401. If the following formula is satisfied, the process proceeds to step (S403):

[0121] CluPrsAct≤TBD9

[0122] Among them, CluPrsAct is the actual oil pressure of the clutch, and TBD9 is a calibration value (second preset oil pressure), such as 2 bar.

[0123] (S403) Speed ​​and Torque Recovery Phase. The generator control mode is adjusted from torque control to speed control. The engine target torque, generator target torque, drive motor target torque, and generator target speed calculated according to the method described in step S401 are adjusted to the target torque and generator target speed values ​​corresponding to the torque distribution in the series drive mode. The adjustment process should ensure the smoothness of the target torque or speed. There are no specific requirements for the implementation method, such as slope limit.

[0124] If the following formulas (d), (e) and (f) are satisfied at the same time, the series-to-parallel switching process ends.

[0125] |EngTqReqsHEV-EngTqAct|≤TBD10 (d)

[0126] |P1SpdReqSHEV-P1SpdAct|≤TBD11 (e)

[0127] |P3TqReqsHEV-P3TqAct|≤TBD12 (f)

[0128] EngTqReqsHEV, P1SpdReqSHEV, and P3TqReqsHEV are respectively the engine target torque, P1 generator target speed, and P3 drive motor target torque output by the torque distribution function in the series drive mode; EngTqAct, P1SpdAct, and P3TqAct are respectively the engine actual torque, P1 generator actual speed, and P3 drive motor actual torque, TBD10 is a calibration value (corresponding to the seventh preset torque value), such as 5Nm, TBD11 is a calibration value (corresponding to the eighth preset speed value), such as 25rpm, and TBD12 is a calibration value (corresponding to the ninth preset torque value), such as 5Nm.

[0129] That is to say, if the absolute value of the difference between the engine target torque and the actual engine torque output by the vehicle's torque distribution module in the series drive mode is less than or equal to the eighth preset torque value, the absolute value of the difference between the generator target speed and the actual generator speed output by the vehicle's torque distribution module in the series drive mode is less than or equal to the eighth preset speed value, and the absolute value of the difference between the drive motor target torque and the actual drive motor torque output by the vehicle's torque distribution module in the series drive mode is less than or equal to the ninth preset torque value, it is determined that the vehicle has completed switching from the parallel drive mode to the series drive mode, and then the vehicle is controlled according to the target torque and target speed allocated to the engine, generator and drive motor respectively in the series drive mode.

[0130] As shown in Figure 3, the present application provides a series-parallel drive mode switching control device for a hybrid vehicle. The hybrid system of the hybrid vehicle includes at least: a power battery, an engine, a drive motor, a generator, and a clutch. The engine can be connected to or disconnected from the wheel end through the clutch. The drive motor is directly connected to the wheel end. The drive motor is connected to the power battery, the generator is connected to the engine, and the generator is connected to the power battery and / or the drive motor. The device includes:

[0131] The parameter reading module 101 is used to read the relevant parameters of the vehicle and the current driving mode of the vehicle when receiving the series-parallel switching request;

[0132] The torque pre-processing module 102 is used to pre-process the target torque of the engine, the generator and the drive motor based on the current driving mode of the vehicle and relevant parameters of the vehicle;

[0133] a target driving mode identification module 103 for identifying a target driving mode of the vehicle based on the received series-parallel switching request;

[0134] The driving mode switching control module 104 is used to control the series-parallel driving mode switching of the vehicle according to relevant parameters of the vehicle, the current driving mode and the target driving mode after completing the torque preprocessing.

[0135] Optionally, the vehicle-related parameters include: vehicle speed, accelerator pedal opening, engine actual torque, generator actual torque, current engine target torque, current generator target torque, current drive motor target torque, generator maximum power generation torque, engine maximum torque, engine to generator speed ratio, generator to drive motor speed ratio, drive motor to wheel end speed ratio and clutch oil pressure. The torque preprocessing module 102 includes:

[0136] The engine maximum available torque determination unit 1021 is used to determine the engine maximum available torque during series-parallel switching based on the generator maximum generating torque and the engine maximum torque;

[0137] An engine and generator target torque determination unit 1022 is configured to determine an engine target torque and a generator target torque during series-parallel switching based on a current vehicle driving mode, a maximum available engine torque during series-parallel switching, and a current engine target torque;

[0138] The engine and generator target torque value updating unit 1023 is used to update the current engine target torque value and the current generator target torque value based on the current driving mode of the vehicle, the engine target torque and the generator target torque during series-parallel switching;

[0139] The drive motor target torque determination and value update unit 1024 is used to determine the drive motor target torque during series-parallel switching based on the driver's required torque, the drive motor-to-wheel speed ratio, the engine-to-generator speed ratio, the generator-to-drive motor speed ratio, the actual engine torque, the actual generator torque, and the clutch oil pressure, and to update the current drive motor target torque value;

[0140] The driver's required torque is obtained by looking up the table based on the vehicle speed and the accelerator pedal opening.

[0141] Optionally, the target driving mode includes a parallel driving mode, and the relevant parameters of the vehicle include: actual generator speed, actual generator torque, actual clutch oil pressure, current generator target speed, and engine target torque, generator target torque, drive motor target torque, and generator target speed output by the vehicle's torque distribution module in the parallel driving mode. If the target driving mode is the parallel driving mode, the driving mode switching control module 104 includes:

[0142] The generator speed synchronization unit 1041 is used to enter the generator speed synchronization phase: set the actual generator torque to the generator target torque, and gradually adjust the current generator target speed to the generator target synchronous speed;

[0143] The clutch closing unit 1042 is configured to enter a clutch closing phase and perform clutch closing control if the absolute value of the difference between the generator synchronization target speed and the generator actual speed is less than a first preset speed value during the generator speed synchronization phase;

[0144] The torque recovery unit 1043 is used to enter the torque recovery stage after completing the clutch closing control if the actual clutch oil pressure is greater than or equal to the first preset oil pressure: the generator control mode is adjusted from speed control to torque control, and the values ​​of the engine target torque, generator target torque, drive motor target torque and generator target speed during series-parallel switching are adjusted to the engine target torque, generator target torque, drive motor target torque and generator target speed output by the vehicle's torque distribution module in the parallel drive mode.

[0145] Optionally, the relevant parameters of the vehicle include: actual engine torque, actual generator torque, actual generator speed, actual clutch oil pressure, engine-to-generator speed ratio, and target engine torque, generator target torque, drive motor target torque, and generator target speed output by the vehicle's torque distribution module in a series drive mode. The target drive mode includes a series drive mode. If the target drive mode is the series drive mode, the drive mode switching control module 104 includes:

[0146] The torque exchange unit 1044 is used to enter the torque exchange phase: gradually increase the generator target torque from 0 to the negative value of the engine target torque during series-parallel switching multiplied by the engine-to-generator speed ratio, and adjust the drive motor target torque to follow the change to meet the driver's torque demand; set the actual generator speed to the generator target speed during series-parallel switching;

[0147] The clutch disconnection unit 1045 is configured to, if the absolute value of the sum of the actual torque of the engine and the actual torque of the generator is less than or equal to a sixth preset torque value during the torque exchange phase, enter the clutch disconnection phase and perform clutch disconnection control;

[0148] The speed torque recovery unit 1046 is used to enter the speed torque recovery stage if the actual clutch oil pressure is less than or equal to the second preset oil pressure after completing the clutch disconnection control: the generator mode control is adjusted from torque control to speed control, and the values ​​of the engine target torque, generator target torque, drive motor target torque, and generator target speed during series-parallel switching are adjusted to the engine target torque, generator target torque, drive motor target torque, and generator target speed output by the vehicle's torque distribution module in the series drive mode.

[0149] The present application also provides a vehicle, comprising the above-mentioned series-parallel drive mode switching control device for a hybrid vehicle.

[0150] The present application also provides a control device, including a processor, a memory, and a program or instruction stored in the memory and executable on the processor. When the program or instruction is executed by the processor, the steps of the series-parallel drive mode switching control method for a hybrid vehicle as described above are implemented.

[0151] The present application also provides a readable storage medium, which stores a program or instruction. When the program or instruction is executed by a processor, the steps of the series-parallel drive mode switching control method of the hybrid vehicle are implemented as described above.

Claims

1. A method for controlling switching between series and parallel driving modes of a hybrid vehicle, characterized in that a hybrid system of the hybrid vehicle at least comprises a power battery, an engine, a driving motor, an electric generator and a clutch, wherein the engine can be connected to or disconnected from a wheel end by means of the clutch, the driving motor is directly connected to the wheel end, the driving motor is connected to the power battery, the electric generator is connected to the engine, the electric generator is connectable to the power battery and / or the driving motor, and the method comprises:reading relevant parameters of the vehicle and a current driving mode of the vehicle when receiving a series-parallel switching request;performing target torque preprocessing on the engine, the electric generator and the driving motor based on the current driving mode of the vehicle and the relevant parameters of the vehicle;identifying a target driving mode of the vehicle based on the received series-parallel switching request; andperforming, after the torque preprocessing is completed, switching control between series and parallel driving modes of the vehicle according to the relevant parameters, the current driving mode and the target driving mode of the vehicle;wherein the relevant parameters of the vehicle comprise: a vehicle speed, an accelerator pedal opening degree, an actual torque of the engine, an actual torque of the electric generator, a current target torque of the engine, a current target torque of the electric generator, a current target torque of the driving motor, a maximum electricity-generating torque of the electric generator, a maximum torque of the engine, an engine-to-electric generator speed ratio, an electric generator-to-driving motor speed ratio, a driving motor-to-wheel end speed ratio and an oil pressure of the clutch; and the step of performing target torque preprocessing on the engine, the electric generator and the driving motor based on the current driving mode of the vehicle and the relevant parameters of the vehicle comprises:determining a maximum available torque of the engine during series-parallel switching2024246157   15 Sep 2026based on the maximum electricity-generating torque of the electric generator and the maximum torque of the engine;determining a target torque of the engine and a target torque of the electric generator during the series-parallel switching based on the current driving mode of the vehicle, the maximum available torque of the engine during the series-parallel switching and the current target torque of the engine;updating a value of the current target torque of the engine and a value of the current target torque of the electric generator based on the current driving mode of the vehicle, and the target torque of the engine and the target torque of the electric generator during the series-parallel switching; anddetermining a target torque of the driving motor during the series-parallel switching based on a driver required torque, the driving motor-to-wheel end speed ratio, the engine-to-electric generator speed ratio, the electric generator-to-driving motor speed ratio, the actual torque of the engine, the actual torque of the electric generator and the oil pressure of the clutch, and updating a value of the current target torque of the driving motor;wherein, the driver required torque is obtained by performing a lookup operation in a table according to the vehicle speed and the accelerator pedal opening degree.

2. The method for controlling switching between series and parallel driving modes of a hybrid vehicle according to claim 1, characterized in thatfirstly, a smaller value selected from an absolute value of the maximum electricitygenerating torque of the electric generator and the maximum torque of the engine is determined, and then a sum of the selected smaller value and a first preset torque value is determined to be the maximum available torque of the engine during the series-parallel switching;a smaller value selected from the maximum available torque of the engine during the series-parallel switching and the current target torque of the engine is determined to be the target torque of the engine during the series-parallel switching;if the current driving mode of the vehicle is a parallel driving mode, the target torque of the electric generator during the series-parallel switching is determined to be 0; and2024246157   15 Sep 2026if the current driving mode of the vehicle is a series driving mode, the target torque of the electric generator during the series-parallel switching is determined to be the actual torque of the electric generator.

3. The method for controlling switching between series and parallel driving modes of a hybrid vehicle according to claim 1 or 2, characterized in that the target driving mode comprises a parallel driving mode; the relevant parameters of the vehicle comprise: an actual torque of the engine, an actual rotation speed of the electric generator, an actual torque of the electric generator, an actual oil pressure of the clutch, a current target rotation speed of the electric generator, as well as a target torque of the engine, a target torque of the electric generator, a target torque of the driving motor and a target rotation speed of the electric generator that are outputted by a torque distribution module of the vehicle in the parallel driving mode; and if the target driving mode is the parallel driving mode, the step of performing switching control between series and parallel driving modes of the vehicle according to the relevant parameters, the current driving mode and the target driving mode of the vehicle comprises:proceeding to an electric generator rotation speed synchronization stage, wherein the actual torque of the electric generator is set to be the target torque of the electric generator and the current target rotation speed of the electric generator is gradually adjusted to a target synchronous rotation speed of the electric generator;when an absolute value of a difference between the target synchronous rotation speed of the electric generator and the actual rotation speed of the electric generator becomes less than a first preset rotation speed value in the electric generator rotation speed synchronization stage, proceeding to a clutch closing stage for clutch closing control; andwhen the actual oil pressure of the clutch becomes greater than or equal to a first preset oil pressure after the clutch closing control is completed, proceeding to a torque recovery stage, wherein an electric generator control mode is converted from rotation speed control to torque control, and values of the target torque of the engine, the target torque of the electric generator, the target torque of the driving motor and the target rotation speed of the electric generator during the series-parallel switching are respectively adjusted to the target torque of the engine,2024246157   15 Sep 2026the target torque of the electric generator, the target torque of the driving motor and the target rotation speed of the electric generator that are outputted by the torque distribution module of the vehicle in the parallel driving mode.

4. The method for controlling switching between series and parallel driving modes of a hybrid vehicle according to claim 3, characterized in that the relevant parameters of the vehicle comprise: a vehicle speed, an electric generator-to-wheel end speed ratio and a tire diameter, wherein the target synchronous rotation speed of the electric generator is calculated by the following formula:PlSpdSyn —VchSpd * 1000 * PIRatio60hDwhere, VehSpd is the vehicle speed, P1Ratio is the electric generator-to-wheel end speedratio, and D is the tire diameter.

5. The method for controlling switching between series and parallel driving modes of a hybrid vehicle according to claim 1 or 2, characterized in that the target driving mode comprises a series driving mode; the relevant parameters of the vehicle comprise: an actual torque of the engine, an actual torque of the electric generator, an actual rotation speed of the electric generator, an actual oil pressure of the clutch, an engine-to-electric generator speed ratio, as well as a target torque of the engine, a target torque of the electric generator, a target torque of the driving motor and a target rotation speed of the electric generator that are outputted by a torque distribution module of the vehicle in the series driving mode; and if the target driving mode is the series driving mode, the step of performing switching control between series and parallel driving modes of the vehicle according to the relevant parameters, the current driving mode and the target driving mode of the vehicle comprises:proceeding to a torque exchange stage wherein a target torque of the electric generator is gradually increased from the target torque of the electric generator during the series-parallel switching to a negative value of the target torque of the engine during the series-parallel switching multiplied by the engine-to-electric generator speed ratio, and at the same time the2024246157   15 Sep 2026target torque of the driving motor is adjusted to follow the change so as to meet a driver required torque, and the actual rotation speed of the electric generator is set to be the target rotation speed of the electric generator during the series-parallel switching;when an absolute value of a sum of the actual torque of the engine and the actual torque of the electric generator becomes less than or equal to a sixth preset torque value in the torque exchange stage, proceeding to a clutch disconnection stage for clutch disconnection control; andwhen the actual oil pressure of the clutch becomes less than or equal to a second preset oil pressure after the clutch disconnection control is completed, proceeding to a rotation speed and torque recovery stage, wherein an electric generator control mode is converted from torque control to rotation speed control, and values of the target torque of the engine, the target torque of the electric generator, the target torque of the driving motor and the target rotation speed of the electric generator during the series-parallel switching are respectively adjusted to the target torque of the engine, the target torque of the electric generator, the target torque of the driving motor and the target rotation speed of the electric generator that are outputted by the torque distribution module of the vehicle in the series driving mode.

6. The method for controlling switching between series and parallel driving modes of a hybrid vehicle according to claim 3, characterized in that, after adjusting the values of the target torque of the engine, the target torque of the electric generator, the target torque of the driving motor and the target rotation speed of the electric generator, the method further comprises:if an absolute value of a difference between the target torque of the engine outputted by the torque distribution module of the vehicle in the parallel driving mode and the actual torque of the engine is less than or equal to a second preset torque value, an absolute value of a difference between the target torque of the electric generator outputted by the torque distribution module of the vehicle in the parallel driving mode and the actual torque of the electric generator is less than or equal to a third preset torque value, and an absolute value of a difference between the target torque of the driving motor outputted by the torque distribution module of the vehicle in the parallel driving mode and the actual torque of the driving motor is less than or equal to a2024246157   15 Sep 2026fourth preset torque value, determining that the switching of the vehicle from the series driving mode to the parallel driving mode is completed.

7. The method for controlling switching between series and parallel driving modes of a hybrid vehicle according to claim 1, characterized in that the target torque P3TqReq of the driving motor during the series-parallel switching is calculated by the following formula:P3TqReq = {DrvTqReq / P3Ratio - (EngTqAct*EngP1Ratio+P1TqAct) / abs(EngTqAct*EngP1Ratio + P1TqAct) *min [abs (EngTqAct*EngP1Ratio+P1TqAct), CluCarryTq]* P1P3Ratio}where, DrvTqReq is the driver required torque, which is obtained by performing a lookup operation in a table according to the vehicle speed and the accelerator pedal opening degree; P3Ratio is the driving motor-to-wheel end speed ratio; EngTqAct is the actual torque of the engine; EngP1Ratio is the engine-to-electric generator speed ratio; P1TqAct is the actual torque of the electric generator; P1P3Ratio is the electric generator-to-driving motor speed ratio; CluCarryTq is a transmissible torque of the clutch; wherein the transmissible torque CluCarryTq of the clutch is obtained by performing a lookup operation in a table based on a clutch oil pressure characteristic curve characterizing an association relationship between an actual oil pressure of the clutch and the transmissible torque CluCarryTq of the clutch.

8. The method for controlling switching between series and parallel driving modes of a hybrid vehicle according to claim 5, characterized in that, after adjusting the target torque of the engine, the target torque of the electric generator, the target torque of the driving motor and the target rotation speed of the electric generator, the method further comprises:if an absolute value of a difference between the target torque of the engine outputted by the torque distribution module of the vehicle in the series driving mode and the actual torque of the engine is less than or equal to an eighth preset torque value, an absolute value of a difference between the target rotation speed of the electric generator outputted by the torque distribution module of the vehicle in the series driving mode and the actual rotation speed of the electric generator is less than or equal to an eighth preset rotation speed value, and an absolute value of2024246157   15 Sep 2026a difference between the target torque of the driving motor outputted by the torque distribution module of the vehicle in the series driving mode and the actual torque of the driving motor is less than or equal to a ninth preset torque value, determining that the switching of the vehicle from the parallel driving mode to the series driving mode is completed.

9. An apparatus for controlling switching between series and parallel driving modes of a hybrid vehicle, characterized in that a hybrid system of the hybrid vehicle at least comprises a power battery, an engine, a driving motor, an electric generator and a clutch, wherein the engine can be connected to or disconnected from a wheel end by means of the clutch, the driving motor is directly connected to the wheel end, the driving motor is connected to the power battery, the electric generator is connected to the engine, the electric generator is connectable to the power battery and / or the driving motor, and the apparatus comprises:a parameter reading module configured to read relevant parameters of the vehicle and a current driving mode of the vehicle when receiving a series-parallel switching request;a torque preprocessing module configured to perform target torque preprocessing on the engine, the electric generator and the driving motor based on the current driving mode of the vehicle and the relevant parameters of the vehicle;a target driving mode identification module configured to identify a target driving mode of the vehicle based on the received series-parallel switching request; anda driving mode switching control module configured to perform, after the torque preprocessing is completed, switching control between series and parallel driving modes of the vehicle according to the relevant parameters, the current driving mode and the target driving mode of the vehicle;wherein the relevant parameters of the vehicle comprise: a vehicle speed, an accelerator pedal opening degree, an actual torque of the engine, an actual torque of the electric generator, a current target torque of the engine, a current target torque of the electric generator, a current target torque of the driving motor, a maximum electricity-generating torque of the electric generator, a maximum torque of the engine, an engine-to-electric generator speed ratio, an electric generator-to-driving motor speed ratio, a driving motor-to-wheel end speed ratio and2024246157   15 Sep 2026an oil pressure of the clutch; and the torque preprocessing module comprises:an engine maximum available torque determining unit configured to determine a maximum available torque of the engine during series-parallel switching based on the maximum electricity-generating torque of the electric generator and the maximum torque of the engine;an engine and electric generator target torque determining unit configured to determine a target torque of the engine and a target torque of the electric generator during the series-parallel switching based on the current driving mode of the vehicle, the maximum available torque of the engine during the series-parallel switching and the current target torque of the engine;an engine and electric generator target torque value updating unit configured to update a value of the current target torque of the engine and a value of the current target torque of the electric generator based on the current driving mode of the vehicle, and the target torque of the engine and the target torque of the electric generator during the series-parallel switching; anda driving motor target torque determining and value updating unit configured to determine a target torque of the driving motor during the series-parallel switching based on a driver required torque, the driving motor-to-wheel end speed ratio, the engine-to-electric generator speed ratio, the electric generator-to-driving motor speed ratio, the actual torque of the engine, the actual torque of the electric generator and the oil pressure of the clutch, and update a value of the current target torque of the driving motor;wherein, the driver required torque is obtained by performing a lookup operation in a table according to the vehicle speed and the accelerator pedal opening degree.

10. The apparatus for controlling switching between series and parallel driving modes of a hybrid vehicle according to claim 9, characterized in that the target driving mode comprises a parallel driving mode; the relevant parameters of the vehicle comprise:an actual torque of the engine, an actual rotation speed of the electric generator, an actual torque of the electric generator, an actual oil pressure of the clutch, a current target rotation speed of the electric generator, as well as a target torque of the engine, a target torque of the electric generator, a target torque of the driving motor and a target rotation speed of the electric2024246157   15 Sep 2026generator that are outputted by a torque distribution module of the vehicle in the parallel driving mode; and if the target driving mode is the parallel driving mode, the driving mode switching control module comprises:an electric generator rotation speed synchronization unit configured to proceed to an electric generator rotation speed synchronization stage, wherein the actual torque of the electric generator is set to be the target torque of the electric generator and the current target rotation speed of the electric generator is gradually adjusted to a target synchronous rotation speed of the electric generator;a clutch closing unit configured to: when an absolute value of a difference between the target synchronous rotation speed of the electric generator and the actual rotation speed of the electric generator becomes less than a first preset rotation speed value in the electric generator rotation speed synchronization stage, proceed to a clutch closing stage for clutch closing control; anda torque recovery unit configured to: when the actual oil pressure of the clutch becomes greater than or equal to a first preset oil pressure after the clutch closing control is completed, proceed to a torque recovery stage, wherein an electric generator control mode is converted from rotation speed control to torque control, and values of the target torque of the engine, the target torque of the electric generator, the target torque of the driving motor and the target rotation speed of the electric generator during the series-parallel switching are respectively adjusted to the target torque of the engine, the target torque of the electric generator, the target torque of the driving motor and the target rotation speed of the electric generator that are outputted by the torque distribution module of the vehicle in the parallel driving mode.

11. The apparatus for controlling switching between series and parallel driving modes of a hybrid vehicle according to claim 9, characterized in that the target driving mode comprises a series driving mode; the relevant parameters of the vehicle comprise: an actual torque of the engine, an actual torque of the electric generator, an actual rotation speed of the electric generator, an actual oil pressure of the clutch, an engine-to-electric generator speed ratio, as well as a target torque of the engine, a target torque of the electric generator, a target torque of2024246157   15 Sep 2026the driving motor and a target rotation speed of the electric generator that are outputted by a torque distribution module of the vehicle in the series driving mode; and if the target driving mode is the series driving mode, the driving mode switching control module comprises:a torque exchange unit configured to proceed to a torque exchange stage wherein a target torque of the electric generator is gradually increased from the target torque of the electric generator during the series-parallel switching to a negative value of the target torque of the engine during the series-parallel switching multiplied by the engine-to-electric generator speed ratio and at the same time the target torque of the driving motor is adjusted to follow the change so as to meet a driver required torque, and the actual rotation speed of the electric generator is set to be the target rotation speed of the electric generator during the series-parallel switching;a clutch disconnection unit configured to: when an absolute value of a sum of the actual torque of the engine and the actual torque of the electric generator becomes less than or equal to a sixth preset torque value in the torque exchange stage, proceed to a clutch disconnection stage for clutch disconnection control; anda rotation speed and torque recovery unit configured to: when the actual oil pressure of the clutch becomes less than or equal to a second preset oil pressure after the clutch disconnection control is completed, proceed to a rotation speed and torque recovery stage, wherein an electric generator control mode is converted from torque control to rotation speed control, and values of the target torque of the engine, the target torque of the electric generator, the target torque of the driving motor and the target rotation speed of the electric generator during the series-parallel switching are respectively adjusted to the target torque of the engine, the target torque of the electric generator, the target torque of the driving motor and the target rotation speed of the electric generator that are outputted by the torque distribution module of the vehicle in the series driving mode.

12. A vehicle, characterized by comprising the apparatus for controlling switching between series and parallel driving modes of a hybrid vehicle according to any one of claims 9 to 11.

13. A control device, characterized by comprising a processor, a memory, and a program or2024246157   15 Sep 2026instructions stored in the memory and executable by the processor, wherein the program or instructions, when executed by the processor, cause the steps of the method for controlling switching between series and parallel driving modes of a hybrid vehicle according to any one of claims 1 to 8 to be implemented.

14. A readable storage medium, characterized by having a program or instructions stored therein, wherein the program or instructions, when executed by a processor, cause the steps of the method for controlling switching between series and parallel driving modes of a hybrid vehicle according to any one of claims 1 to 8 to be implemented.

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