A control method, device, vehicle, equipment and medium for switching between series-parallel drive modes of a hybrid vehicle

Abstract

The present invention provides a control method, device, vehicle, equipment and medium for switching between series-parallel drive modes of a hybrid vehicle, which are used to solve the problems of inability to complete series-parallel switching, inability to adjust the speed of the P1 generator, and unexpected acceleration and deceleration of the vehicle caused by the mismatch in the selection of the engine and the P1 generator. The present invention provides a control method for switching between series-parallel drive modes of a hybrid vehicle, and the method includes: when receiving a series-parallel switching request, reading relevant parameters of the vehicle and the current drive mode of the vehicle; based on the current drive mode of the vehicle and the relevant parameters of the vehicle, performing target torque preprocessing on the engine, generator and drive motor; based on the received series-parallel switching request, identifying the target drive mode of the vehicle; after completing the torque preprocessing, performing control for switching between series-parallel drive modes of the vehicle according to the relevant parameters of the vehicle, the current drive mode and the target drive mode.

Description

Technical Field

[0001] The present invention relates to the field of control of hybrid vehicles, and particularly to a control method, device, vehicle, equipment and medium for switching between series-parallel drive modes of a hybrid vehicle. Background Art

[0002] In recent years, in the face of the oil energy crisis and increasingly strict fuel consumption regulations, hybrid vehicles have become a research focus of major manufacturers. Among them, the P13 configuration, as a relatively easy-to-implement hybrid configuration, is taken as an example and has been studied more and more. For example Figure 1 , when the vehicle is at a low speed, the K3 clutch is disengaged, and the whole vehicle operates in a series drive mode. The engine does not directly participate in driving, but generates electricity through the P1 generator. The P3 drive motor obtains electrical energy through the power battery or the P1 generator and conducts driving. When the vehicle is at a medium or high speed, the K3 clutch is engaged, and the whole vehicle operates in a parallel drive mode. The engine directly participates in driving, and the P3 motor assists in adjusting the operating point of the engine to ensure that the engine is in the low fuel consumption economic zone. Based on the vehicle economy and power demand, the optimal drive mode is selected according to the vehicle state. The typical series-parallel drive mode switching process requires the coordination of the engine speed, P1 generator speed, P3 drive motor speed and torque, as well as the control of the K3 clutch, which is relatively complex and has been studied more and more.

[0003] CN113335262A - Control method, vehicle and storage medium for switching drive modes of a hybrid vehicle. This patent provides a series-to-parallel switching control method, including adjusting the engine torque to the engine target torque in the parallel drive mode, adjusting the engine speed to the same as the drive motor speed in the series drive mode, engaging the clutch, reducing the generator torque to 0 and at the same time reducing the drive motor by the same torque as the generator. The parallel-to-series control method includes increasing the generator negative torque to absorb the engine torque, adjusting 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 solution provides a basic control method for the series-parallel switching process, there are obvious problems as follows: 1. The matching of the engine and generator models is not considered. For example, the target torque of the engine in the parallel drive mode exceeds the maximum power generation torque of the P1 generator, and 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 engine negative torque in the parallel drive mode, resulting in the inability to complete the series-parallel switching. 2. When the P1 generator is generating electricity at its maximum capacity, it cannot be speed-adjusted and the series-parallel switching cannot be completed either. 3. The torque transmission characteristics of the clutch engagement and disengagement are not considered, which brings unexpected acceleration and deceleration to the vehicle. Summary of the Invention

[0005] The present invention provides a method, device, vehicle, equipment and medium for controlling the series-parallel drive mode switching of a hybrid vehicle, which is used to solve the problems that the selection of the engine and the P1 generator does not match, the P1 generator cannot adjust the speed, resulting in the inability to complete the series-parallel switching, and the vehicle will have unexpected acceleration and deceleration during the series-parallel switching process.

[0006] The technical solution of the present invention is as follows:

[0007] The present invention provides a method for controlling the series-parallel drive mode switching of a hybrid vehicle. The hybrid system of the hybrid vehicle at least includes: a power battery, an engine, a drive motor, a generator and a clutch. The engine can be coupled 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. The generator is connected to the power battery and / or the drive motor. The method includes:

[0008] When receiving a series-parallel switching request, read the relevant parameters of the vehicle and the current drive mode of the vehicle;

[0009] Based on the current drive mode of the vehicle and the relevant parameters of the vehicle, perform target torque preprocessing on the engine, generator and drive motor;

[0010] Based on the received series-parallel switching request, identify the target drive mode of the vehicle;

[0011] After completing the torque preprocessing, perform 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.

[0012] Preferably, 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 power generation 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 steps of performing target torque preprocessing on the engine, generator and drive motor based on the current drive mode of the vehicle and the relevant parameters of the vehicle include:

[0013] Based on the maximum generator power generation torque and the maximum engine torque, determine the maximum available engine torque during series-parallel switching;

[0014] Based on the current drive mode of the vehicle, the maximum available engine torque during series-parallel switching and the current engine target torque, determine the engine target torque and the generator target torque during series-parallel switching;

[0015] Based on the current driving mode of the vehicle, the engine target torque and the generator target torque during series-parallel switching, and update the values of the current engine target torque and the current generator target torque;

[0016] Based on the driver demand 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, determine the drive motor target torque during series-parallel switching, and update the value of the current drive motor target torque;

[0017] Among them, the driver demand torque is obtained by looking up a table according to the vehicle speed and the throttle pedal opening.

[0018] Preferably, first determine the smaller value between the absolute value of the maximum power generation torque of the generator and the maximum torque of the engine, and then determine the sum of the smaller value and the first preset torque value as the maximum available torque of the engine during series-parallel drive mode switching control;

[0019] Determine the smaller value between the maximum available torque of the engine during series-parallel switching and the current engine target torque as the engine target torque during series-parallel drive mode switching control;

[0020] If the current driving mode of the vehicle is the parallel drive mode, determine that the generator target torque during series-parallel switching is 0;

[0021] If the current driving mode of the vehicle is the series drive mode, determine that the generator target torque during series-parallel switching is the actual generator torque.

[0022] Preferably, the target driving mode includes the parallel drive mode, and the relevant parameters of the vehicle include: the actual engine torque, the actual generator speed, the actual generator torque, the actual clutch oil pressure, the current generator target speed, and the engine target torque, generator target torque, drive motor target torque, and generator target speed output by the vehicle torque distribution module in the parallel drive mode. If the target driving mode is the parallel drive mode, the steps for series-parallel drive mode switching control of the vehicle according to the relevant parameters of the vehicle, the current driving mode, and the target driving mode include:

[0023] 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 synchronization speed;

[0024] During the generator speed synchronization stage, if the absolute value of the difference between the generator synchronization target speed and the actual generator speed is less than the first preset speed value, enter the clutch closing stage: Perform clutch closing control;

[0025] After the clutch closing control is completed, if the actual clutch oil pressure is greater than or equal to the first preset oil pressure, enter the torque recovery stage: adjust the generator control mode from speed control to torque control, and correspondingly adjust the values of the engine target torque, generator target torque, drive motor target torque, and generator target speed during series-parallel switching 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.

[0026] Preferably, the relevant parameters of the vehicle include: vehicle speed, generator-to-wheel speed ratio, and tire diameter; among them, the generator target synchronous speed is calculated by the formula:

[0027]

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

[0029] Preferably, 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 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. The target drive mode includes the series drive mode. If the target drive mode is the series drive mode, according to the relevant parameters of the vehicle, the current drive mode, and the target drive mode, the steps for switching control of the vehicle's series-parallel drive mode include:

[0030] Enter the torque exchange stage: gradually increase 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, 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 during series-parallel switching;

[0031] If in the torque exchange stage, the absolute value of the sum of the actual engine torque and the actual generator torque is less than or equal to the sixth preset torque value, enter the clutch disconnection stage: perform clutch disconnection control;

[0032] After the clutch disconnection control is completed, if the actual clutch oil pressure is less than or equal to the second preset oil pressure, enter the speed-torque recovery stage: adjust the generator mode control from torque control to speed control, and respectively adjust the values of the engine target torque, generator target torque, drive motor target torque, and generator target speed during series-parallel switching 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] Preferably, after the numerical adjustment of the engine target torque, the generator target torque, the drive motor target torque, and the generator target speed is completed, the method further includes:

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

[0035] Preferably, the drive motor target torque P3TqReq during series-parallel switching is obtained through the formula:

[0036] P3TqReq = {DrvTqReq / P3Ratio - (EngTqAct*EngP1Ratio + P1TqAct) / abs(EngTqAct

[0037] *EngP1Ratio + P1TqAct)*min[abs(EngTqAct*EngP1Ratio

[0038] + P1TqAct), CluCarryTq]*P1P3Ratio}

[0039] The calculation is obtained as follows: DrvTqReq is the driver demand torque, which is obtained by looking up a table according to the vehicle speed and the throttle pedal opening; P3Ratio is the speed ratio from the drive motor to the wheel end; EngTqAct is the engine actual torque; EngP1Ratio is the speed ratio from the engine to the generator; P1TqAct is the generator actual torque; P1P3Ratio is the speed ratio from the generator to the drive motor; CluCarryTq is the clutch transmissible torque, and the clutch transmissible torque CluCarryTq is obtained by looking up a table from the clutch oil pressure characteristic curve representing the relationship between the actual clutch oil pressure and the clutch transmissible torque CluCarryTq.

[0040] Preferably, after the adjustment of the engine target torque, the generator target torque, the drive motor target torque, and the generator target speed is completed, the method further includes:

[0041] If the absolute value of the difference between the target engine torque and the actual engine torque output by the torque distribution module of the vehicle in the series drive mode is less than or equal to the eighth preset torque value, the absolute value of the difference between the target generator speed and the actual generator speed output by the torque distribution module of the vehicle in the series drive mode is less than or equal to the eighth preset torque value, and the absolute value of the difference between the target drive motor torque and the actual drive motor torque output by the torque distribution module of the vehicle in the series drive mode is less than or equal to the ninth preset torque value, it is determined that the vehicle has completed the switch from the parallel drive mode to the series drive mode.

[0042] The present invention also provides a control device for switching between series and parallel drive modes of a hybrid vehicle. The hybrid system of the hybrid vehicle at least includes: a power battery, an engine, a drive motor, a generator, and a clutch. The engine can be coupled 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. The generator is connected to the power battery and / or the drive motor. The device includes:

[0043] A parameter reading module, configured to read relevant parameters of the vehicle and the current drive mode of the vehicle when receiving a series-parallel switching request;

[0044] A torque preprocessing module, configured to perform target torque preprocessing on the engine, the generator, and the drive motor based on the current drive mode of the vehicle and the relevant parameters of the vehicle;

[0045] A target drive mode recognition module, configured to recognize the target drive mode of the vehicle based on the received series-parallel switching request;

[0046] A drive mode switching control module, configured to perform series-parallel drive mode switching control of the vehicle based on the relevant parameters of the vehicle, the current drive mode, and the target drive mode after completing the torque preprocessing.

[0047] Preferably, the relevant parameters of the vehicle include: 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 power generation 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:

[0048] An engine maximum available torque determination unit, configured to determine the maximum available torque of the engine during series-parallel switching based on the maximum generator power generation torque and the maximum engine torque;

[0049] An engine and generator target torque determination unit for determining the engine target torque and generator target torque during series-parallel switching based on the current driving mode of the vehicle, the maximum available torque of the engine during series-parallel switching, and the current engine target torque;

[0050] An engine and generator target torque value update unit for updating the values of the current engine target torque and the current generator target torque based on the current driving mode of the vehicle, the engine target torque and generator target torque during series-parallel switching;

[0051] A drive motor target torque determination and value update unit for determining the drive motor target torque during series-parallel switching based on the driver demand torque, the drive motor to wheel end 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 updating the value of the current drive motor target torque;

[0052] Wherein, the driver demand torque is obtained by looking up a table according to the vehicle speed and the throttle pedal opening.

[0053] Preferably, the target driving mode includes a parallel driving mode, and the relevant parameters of the vehicle include: the actual engine torque, the actual generator speed, the actual generator torque, the actual clutch oil pressure, the current generator target speed, and 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 driving mode. If the target driving mode is the parallel driving mode, the driving mode switching control module includes:

[0054] A generator speed synchronization unit for entering the generator speed synchronization stage: setting the actual generator torque to the generator target torque and gradually adjusting the current generator target speed to the generator target synchronization speed;

[0055] A clutch closing unit for entering the clutch closing stage if the absolute value of the difference between the generator synchronization target speed and the actual generator speed is less than the first preset speed value during the generator speed synchronization stage: performing clutch closing control;

[0056] A torque recovery unit for entering 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: adjusting the generator control mode from speed control to torque control, and correspondingly adjusting the values of the engine target torque, generator target torque, drive motor target torque, and generator target speed during series-parallel switching 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 driving mode.

[0057] Preferably, the relevant parameters of the vehicle include: the actual engine torque, the actual generator torque, the actual generator speed, the actual clutch oil pressure, the engine-to-generator speed ratio, and 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. The target drive mode includes 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 for entering the torque exchange stage: gradually increasing the generator target torque from the generator target torque at the series-parallel switch to the negative value of the engine target torque at the series-parallel switch multiplied by the engine-to-generator speed ratio, and at the same time adjusting the drive motor target torque to follow the change to meet the driver's required torque; setting the actual generator speed to the generator target speed at the series-parallel switch;

[0058] A clutch disconnection unit for entering the clutch disconnection stage if, during the torque exchange stage, the absolute value of the sum of the actual engine torque and the actual generator torque is less than or equal to the sixth preset torque value: performing clutch disconnection control;

[0059] A speed and torque recovery unit for, if the actual clutch oil pressure is less than or equal to the second preset oil pressure after the clutch disconnection control is completed, entering the speed and torque recovery stage: adjusting the generator mode control from torque control to speed control, and respectively adjusting the values of the engine target torque, generator target torque, drive motor target torque, and generator target speed at the series-parallel switch 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.

[0060] The present invention also provides a vehicle, including the series-parallel drive mode switching control device of the above hybrid vehicle.

[0061] The present invention also provides a control device, including a processor, a memory, and a program or instruction stored on 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 of the above hybrid vehicle are implemented.

[0062] The present invention also provides a readable storage medium, on which a program or instruction is stored. When the program or instruction is executed by a processor, the steps of the series-parallel drive mode switching control method of the above hybrid vehicle are implemented.

[0063] The beneficial effects of the present invention are:

[0064] When a series - parallel switching request is received, to avoid problems such as the inability to update to the target torque or speed of the target drive mode due to a mismatch between the engine and generator selections, and the inability to adjust the speed. Especially when the vehicle is operating in the parallel drive mode, there may be a situation where the target torque of the engine exceeds the coupling boundary capacity of the engine and the generator. This solution proposes to pre - process the target torques of the engine and the generator before series - parallel switching. By calculating the coupling boundary of the engine and the generator, and reserving torque for adjusting the speed at the coupling boundary, the processed coupling boundary is used to limit the target torques of the engine and the generator as the target torques during the series - parallel switching process. At the same time, to ensure the driver's required torque, the target torque of the drive motor is also adjusted adaptively. Through the above - mentioned solution, the problems of being unable to update to the target torque of the target drive mode during series - parallel switching and being unable to adjust the speed during the series - parallel switching process can be completely solved. In addition, during the clutch filling and draining process, considering the torque transmission characteristics of the clutch when calculating the target torque of the power source can make the calculation of the target torque of the power source more reasonable and in line with the actual situation, avoiding the problem of unexpected acceleration and deceleration of the vehicle caused by ignoring the actual torque output of the power source to the vehicle end during the clutch filling and draining process. Description of the Drawings

[0065] Figure 1 It is a schematic diagram of the P13 configuration in this embodiment;

[0066] Figure 2 It is a flowchart of the method in this embodiment;

[0067] Figure 3 It is a structural block diagram of the device in this embodiment. Detailed Embodiments

[0068] The following will describe the embodiments of the present invention with reference to the drawings and preferred embodiments. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be understood that the preferred embodiments are only for explaining the present invention, rather than for limiting the protection scope of the present invention.

[0069] It should be noted that the diagrams provided in the following embodiments only illustrate the basic concept of the present invention in a schematic manner. Therefore, only the components related to the present invention are shown in the diagrams, rather than being drawn according to the number, shape, and size of the components in actual implementation. The type, quantity, and ratio of each component in actual implementation can be arbitrarily changed, and the component layout type may also be more complex.

[0070] Refer to Figure 1The series-parallel drive mode switching control method for a hybrid vehicle provided in this embodiment is mainly applicable to hybrid vehicles with the following characteristics: a hybrid vehicle at least comprising: 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. Figure 1 For the P13 hybrid vehicle, the generator is Figure 1 The P1 motor in the figure is the drive motor. Figure 1 The P3 motor in the clutch refers to Figure 1 For a hybrid vehicle with a P13 configuration, the P1 generator is connected to both the power battery and the P3 drive motor. In this embodiment, the hybrid vehicle described above can also be applied to vehicles with other configurations, as long as the vehicles have the aforementioned specific features.

[0071] like Figure 2 The series-parallel driving mode switching control method of the hybrid vehicle provided in this embodiment specifically includes:

[0072] 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;

[0073] 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;

[0074] 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;

[0075] 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.

[0076] 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.

[0077] In this embodiment, for the determination function of the series-parallel switching timing in step S1, specifically, it is also possible to output a series-parallel switching request by comprehensively considering the economy and power performance of the vehicle based on the vehicle state and the driver's demand. This series-parallel switching request can be a request obtained by using existing technologies (such as the method introduced in the background technology). The specific information carried in this series-parallel switching request signal can be a parallel-to-series switching request when the vehicle needs to switch from the parallel drive mode to the series drive mode or a series-to-parallel switching request when the vehicle needs to switch from the series drive mode to the parallel drive mode.

[0078] In this embodiment, the process of torque preprocessing in step S2 can be specifically understood as follows: Based on the maximum power generation torque of the generator and the maximum torque of the engine, determine the maximum available torque of the engine during series-parallel switching; Based on the current drive mode of the vehicle, the maximum available torque of the engine during series-parallel switching, and the current engine target torque, determine the engine target torque and the generator target torque during series-parallel switching; Based on the current drive mode of the vehicle, the engine target torque and the generator target torque during series-parallel switching, and update the values of the current engine target torque and the current generator target torque; Based on the driver's demand torque, the speed ratio from the drive motor to the wheel, the speed ratio from the engine to the generator, the speed ratio from the generator to the drive motor, the actual torque of the engine, the actual torque of the generator, and the clutch oil pressure, determine the target torque of the drive motor during series-parallel switching, and update the value of the current drive motor target torque. Among them, the relevant parameters of the vehicle mentioned above include: vehicle speed, throttle pedal opening, actual torque of the engine, actual torque of the generator, current engine target torque, current generator target torque, current drive motor target torque, maximum power generation torque of the generator, maximum torque of the engine, speed ratio from the engine to the drive motor, speed ratio from the generator to the drive motor, speed ratio from the drive motor to the wheel, and clutch oil pressure.

[0079] In this embodiment, EngTqMax SPC is the maximum available torque of the engine during series-parallel switching, and its calculation formula is as follows:

[0080] EngTqMax SPC = min([EngTqMax, abs(P1GenTqMax)]) - TBD1

[0081] Among them, 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 in the P13 configuration), and TBD1 is a calibrated value.

[0082] Furthermore, EngTqReq SPC is the engine target torque during series-parallel switching, and the specific calculation formula is as follows:

[0083] EngTqReq SPC = min(EngTqReq, EngTqMax SPC )

[0084] Among them, EngTqReq is the current engine target torque.

[0085] The target torque P3TqReq of the drive motor during series - parallel switching is obtained through the formula:

[0086] P3TqReq = {DrvTqReq / P3Ratio - (EngTqAct * EngP1Ratio + P1TqAct) / abs(EngTqAct

[0087] * EngP1Ratio + P1TqAct) * min[abs(EngTqAct * EngP1Ratio

[0088] + P1TqAct), CluCarryTq] * P1P3Ratio}

[0089] It is calculated that DrvTqReq is the driver - demand torque, which is obtained by looking up a table according to the vehicle speed and the throttle 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 generator torque, P1P3Ratio is the speed ratio from the generator to the drive motor, and CluCarryTq is the clutch - transmissible torque, which is obtained by looking up a table from the clutch - oil - pressure characteristic curve representing the relationship between the actual clutch oil pressure and the clutch - transmissible torque CluCarryTq.

[0090] In step S3, first, based on the received series - parallel switching request, the target drive mode of the vehicle is identified as the parallel - drive mode.

[0091] The specific process of series - parallel drive - mode switching control is as follows: According to the relevant parameters of the vehicle, the current drive mode, and the target drive mode, the series - parallel drive - mode switching control of the vehicle is carried out.

[0092] Such as Figure 2 , this step S3 specifically includes the following steps:

[0093] (S301) Speed synchronization stage. Specifically, according to the calculation methods described in step S2, the engine target torque at series-parallel switching, the generator target torque at series-parallel switching, and the drive motor target torque at series-parallel switching are obtained. The generator target speed is gradually adjusted from the current generator target speed to the generator target synchronous speed at series-parallel switching. The generator target synchronous speed at series-parallel switching is calculated from the vehicle speed, the speed ratio from the generator to the wheel end, and the tire diameter. The adjustment process should ensure the smoothness of the target speed, and the implementation method is not specifically required, such as slope limitation.

[0094] If the following formula is satisfied, then enter step (302).

[0095] |P1SpsReq syn -P1SpdAct|≤TBD2

[0096] Wherein, P1SpsReq syn is the generator synchronous target speed at series-parallel switching (the P1 generator target synchronous speed in the P13 configuration in this embodiment), P1SpdAct is the actual speed of the P1 motor, and TBD2 is a calibrated value (the first preset speed value), such as 50 rpm.

[0097] Furthermore, for the generator target synchronous speed P1SpdReq syn at series-parallel switching, its calculation formula is as follows:

[0098]

[0099] Wherein, VehSpd is the vehicle speed, η P1 is the speed ratio from the P1 generator to the drive motor, and D is the tire diameter.

[0100] (S302) Clutch closing stage. Specifically, the clutch solenoid valve is opened, and the hydraulic module is filled with oil to complete the clutch closing.

[0101] The engine target torque at series-parallel switching and the generator target torque obtained according to the calculation methods described in step S2, and the generator target speed at series-parallel switching obtained according to the calculation method described in step S301.

[0102] If the following formula is satisfied, then enter step (S303):

[0103] CluPrsAct≥TBD3

[0104] Wherein, CluPrsAct is the actual oil pressure of the clutch (obtained by the transmission control unit), and TBD3 is a calibrated value (the first preset oil pressure), such as 10 bar.

[0105] (S303) Torque recovery phase. Specifically, change the generator control mode from speed control to torque control, and adjust the engine target torque, generator target torque calculated according to the method described in step S2 during series-parallel switching, the drive motor target torque calculated according to the method described in step S302 during series-parallel switching, and the generator target speed calculated according to the method described in step S301 during series-parallel switching to the target torque values and generator target speed values respectively output by the vehicle's torque distribution module in the parallel drive mode. During the adjustment process, the smoothness of the target torque should be ensured, and the implementation method is not specifically required, such as achieving it by slope limiting or other means.

[0106] Further, if the following formulas (a), (b), and (c) are satisfied simultaneously, the series-to-parallel switching process ends.

[0107] |EngTqReq PHEV -EngTqAct|≤TBD4 (a)

[0108] |P1TqReq PHEV -P1TqAct|≤TBD5 (b)

[0109] |P3TqReq PHEV -P3TqAct|≤TBD6 (c)

[0110] EngTqReq PHEV 、P1TqReq PHEV 、P3TqReq PHEV are the engine target torque, generator target torque (the P1 generator target torque in the P13 configuration in this embodiment), and drive motor target torque (the P3 drive motor target torque in the P13 configuration in this embodiment) output by the torque distribution function in the parallel drive mode respectively; EngTqAct, P1TqAct, and P3TqAct are the actual engine torque, actual generator torque (the actual P1 generator torque in the P13 configuration in this embodiment), and actual drive motor torque (the actual P13 drive motor torque in the P13 configuration in this embodiment) respectively; TBD4 is a calibrated value (corresponding to the second preset torque value), such as 5 Nm, TBD5 is a calibrated value (corresponding to the third preset torque value), such as 5 Nm, and TBD6 is a calibrated value (corresponding to the fourth preset torque value), such as 5 Nm.

[0111] That is to say, if the absolute value of the difference between the target engine torque and the actual engine torque output by the torque distribution module of the vehicle in the parallel drive mode is less than or equal to the second preset torque value, the absolute value of the difference between the target generator torque and the actual generator torque output by the torque distribution module of the vehicle 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 target drive motor torque and the actual drive motor torque output by the torque distribution module of the vehicle in the parallel drive mode is less than or equal to the fourth preset torque value, it is determined that the vehicle has completed the switch from the series drive mode to the parallel drive mode, and then the vehicle is controlled according to the target torques respectively allocated to the engine, the generator, and the drive motor in the parallel drive mode.

[0112] (S4) The parallel-to-series switching module specifically performs the following steps:

[0113] (S401) Torque exchange stage. Specifically, the current target engine torque is gradually adjusted to the target engine torque at the series-parallel switch, while the target generator torque is gradually increased from the target generator torque at the series-parallel switch to the negative value of the target engine torque at the series-parallel switch multiplied by the engine-to-generator speed ratio. At the same time, the target drive motor torque is adjusted to follow the change to meet the driver's required torque, and the actual generator speed is set to the target generator speed at the series-parallel switch.

[0114] Among them, the calculation formula for the target generator torque P1TqReq at the series-parallel switch is:

[0115] P1TqReq = -EngTqReq * EngP1Ratio

[0116] . EngTqReq is the target engine torque at the series-parallel switch calculated by the method described in step S2, and EngP1Ratio is the engine-to-generator speed ratio.

[0117] The target drive motor torque at the series-parallel switch is obtained according to the following calculation method. At this time, the target drive motor torque P3TqReq at the series-parallel switch is calculated by the formula:

[0118] P3TqReq = {DrvTqReq / P3Ratio - (EngTqAct * EngP1Ratio + P1TqAct) / abs(EngTqAct

[0119] * EngP1Ratio + P1TqAct) * min[abs(EngTqAct * EngP1Ratio

[0120] + P1TqAct), CluCarryTq] * P1P3Ratio}

[0121] Calculated, DrvTqReq is the driver demand torque, obtained by looking up a table according to the vehicle speed and the throttle 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 generator torque. P1P3Ratio is the speed ratio from the generator to the drive motor. CluCarryTq is the clutch transmissible torque, obtained by looking up a table from the clutch oil pressure characteristic curve that characterizes the relationship between the actual clutch oil pressure and the clutch transmissible torque CluCarryTq.

[0122] If the following formula is satisfied, go to step (S402)

[0123] |EngTqAct + P1TqAct| ≤ TBD8

[0124] EngTqAct is the actual engine torque; P1TqAct is the actual generator torque;

[0125] Wherein, TBD8 is a calibrated value (the sixth preset torque value), such as 5 Nm.

[0126] (S402) Clutch disengagement stage. Specifically, the clutch solenoid valve is closed, and the hydraulic module releases the oil pressure to complete the clutch disengagement;

[0127] The engine target torque, generator target torque, drive motor target torque, and generator target speed obtained according to the calculation method described in step S401. If the following formula is satisfied, go to step (S403):

[0128] CluPrsAct ≤ TBD9

[0129] Wherein, CluPrsAct is the actual clutch oil pressure, and TBD9 is a calibrated value (the second preset oil pressure), such as 2 bar.

[0130] (S403) Speed and torque recovery stage. Adjust the generator control mode from torque control to speed control, and adjust the engine target torque, generator target torque, drive motor target torque, and generator target speed obtained according to the method described in step S401 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, and the implementation method is not specifically required, such as slope limitation.

[0131] If the following formulas (d), (e), and (f) are satisfied simultaneously, the series-to-parallel switching process ends.

[0132] |EngTqReqs HEV-EngTqAct|≤TBD10 (d)

[0133] |P1SpdReq SHEV -P1SpdAct|≤TBD11 (e)

[0134] |P3TqReqs HEV -P3TqAct|≤TBD12 (f)

[0135] EngTqReqs HEV , P1SpdReq SHEV , P3TqReqs HEV are the engine target torque, the P1 generator target speed, and the P3 drive motor target torque output by the torque distribution function in the series drive mode respectively; EngTqAct, P1SpdAct, and P3TqAct are the engine actual torque, the P1 generator actual speed, and the P3 drive motor actual torque respectively. TBD10 is a calibrated value (corresponding to the seventh preset torque value), such as 5 Nm, TBD11 is a calibrated value (corresponding to the eighth preset torque value), such as 25 rpm, and TBD12 is a calibrated value (corresponding to the ninth preset torque value), such as 5 Nm.

[0136] That is to say, if the absolute value of the difference between the engine target torque and the engine actual torque output by the torque distribution module of the vehicle 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 generator actual speed output by the torque distribution module of the vehicle in the series drive mode is less than or equal to the eighth preset torque value, and the absolute value of the difference between the drive motor target torque and the drive motor actual torque output by the torque distribution module of the vehicle in the series drive mode is less than or equal to the ninth preset torque value, it is determined that the vehicle has completed the switch from the parallel drive mode to the series drive mode, and then the control is carried out according to the target torques respectively allocated to the engine, the generator, and the drive motor in the series drive mode.

[0137] For example Figure 3 , the present invention provides a series-parallel drive mode switching control device for a hybrid vehicle. The hybrid system of the hybrid vehicle at least includes: a power battery, an engine, a drive motor, a generator, and a clutch. The engine can be coupled 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. The generator is connected to the power battery and / or the drive motor. The device includes:

[0138] A parameter reading module 101, configured to read relevant parameters of the vehicle and the current drive mode of the vehicle when receiving a series-parallel switching request;

[0139] The torque preprocessing module 102 is configured to perform target torque preprocessing on the engine, generator, and drive motor based on the current driving mode of the vehicle and relevant parameters of the vehicle;

[0140] The target driving mode recognition module 103 is configured to recognize the target driving mode of the vehicle based on the received series-parallel switching request;

[0141] The driving mode switching control module 104 is configured to perform series-parallel driving mode switching control of the vehicle based on relevant parameters of the vehicle, the current driving mode, and the target driving mode after completing the torque preprocessing.

[0142] Preferably, 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 power generation 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 102 includes:

[0143] The engine maximum available torque determination unit 1021 is configured to determine the maximum available torque of the engine during series-parallel switching based on the maximum generator power generation torque and the maximum engine torque;

[0144] The engine and generator target torque determination unit 1022 is configured to determine the engine target torque and the generator target torque during series-parallel switching based on the current driving mode of the vehicle, the maximum available torque of the engine during series-parallel switching, and the current engine target torque;

[0145] The engine and generator target torque value update unit 1023 is configured to update the values of the current engine target torque and the current generator target torque based on the current driving mode of the vehicle, the engine target torque and the generator target torque during series-parallel switching;

[0146] The drive motor target torque determination and value update unit 1024 is configured to determine the drive motor target torque during series-parallel switching based on the driver demand torque, the drive motor-to-wheel end 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 update the value of the current drive motor target torque;

[0147] Wherein, the driver demand torque is obtained by looking up a table according to the vehicle speed and the accelerator pedal opening.

[0148] Preferably, the target driving mode includes a parallel driving mode, and the relevant parameters of the vehicle include: the actual generator speed, the actual generator torque, the actual clutch oil pressure, the current target generator speed, and the engine target torque, the generator target torque, the driving motor target torque, and the target generator 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:

[0149] The generator speed synchronization unit 1041 is used to enter the generator speed synchronization stage: set the actual generator torque to the target generator torque, and gradually adjust the current target generator speed to the target generator synchronization speed;

[0150] The clutch closing unit 1042 is used to enter the clutch closing stage if the absolute value of the difference between the target generator synchronization speed and the actual generator speed is less than the first preset speed value during the generator speed synchronization stage: perform clutch closing control;

[0151] The torque recovery unit 1043 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 the clutch closing control is completed: then adjust the generator control mode from speed control to torque control, and correspondingly adjust the values of the engine target torque, the generator target torque, the driving motor target torque, and the target generator speed during series-parallel switching to the engine target torque, the generator target torque, the driving motor target torque, and the target generator speed output by the vehicle's torque distribution module in the parallel driving mode.

[0152] Preferably, the relevant parameters of the vehicle include: the actual engine torque, the actual generator torque, the actual generator speed, the actual clutch oil pressure, the engine-to-generator speed ratio, and the engine target torque, the generator target torque, the driving motor target torque, and the target generator speed output by the vehicle's torque distribution module in the series driving mode. The target driving mode includes a series driving mode. If the target driving mode is the series driving mode, the driving mode switching control module 104 includes:

[0153] The torque exchange unit 1044 is used to enter the torque exchange stage: 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 at the same time adjust the driving motor target torque to follow the change to meet the driver's required torque; set the actual generator speed to the target generator speed during series-parallel switching;

[0154] The clutch disconnection unit 1045 is used to enter the clutch disconnection stage if the absolute value of the sum of the actual engine torque and the actual generator torque is less than or equal to the sixth preset torque value during the torque exchange stage: perform clutch disconnection control;

[0155] A rotational speed and torque recovery unit 1046, which is used to, after the clutch disconnection control is completed, if the actual oil pressure of the clutch is less than or equal to the second preset oil pressure, in the rotational speed and torque recovery stage: adjust the generator mode control from torque control to speed control, and adjust the values of the engine target torque, generator target torque, drive motor target torque, and generator target speed during series-parallel switching 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 respectively.

[0156] The present invention also provides a vehicle, including the series-parallel drive mode switching control device of the above hybrid vehicle.

[0157] The present invention also provides a control device, including a processor, a memory, and a program or instruction stored on 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 of the above hybrid vehicle are implemented.

[0158] The present invention also provides a readable storage medium, on which a program or instruction is stored. When the program or instruction is executed by a processor, the steps of the series-parallel drive mode switching control method of the above hybrid vehicle are implemented.

Claims

1. A control method for switching between series-parallel drive modes of a hybrid vehicle, characterized in that, The hybrid system of the hybrid vehicle at least includes: a power battery, an engine, a drive motor, a generator, and a clutch. The engine can be coupled 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. The generator is connected to the power battery and / or the drive motor. The method includes: When receiving a series-parallel switching request, read the relevant parameters of the vehicle and the current driving mode of the vehicle; Based on the current driving mode of the vehicle and the relevant parameters of the vehicle, perform target torque preprocessing on the engine, generator, and drive motor; Based on the received series-parallel switching request, identify the target driving mode of the vehicle; After completing the torque preprocessing, perform series-parallel driving mode switching control on the vehicle according to the relevant parameters of the vehicle, the current driving mode, and the target driving mode; 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 power generation 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 steps of performing target torque preprocessing on the engine, generator, and drive motor based on the current driving mode of the vehicle and the relevant parameters of the vehicle include: Based on the maximum generator power generation torque and the maximum engine torque, determine the maximum available engine 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 engine target torque, determine the engine target torque and the generator target torque during series-parallel switching; Based on the current driving mode of the vehicle, the engine target torque and the generator target torque during series-parallel switching, and update the values of the current engine target torque and the current generator target torque; Based on the driver demand torque, drive motor-to-wheel end speed ratio, engine-to-generator speed ratio, generator-to-drive motor speed ratio, actual engine torque, actual generator torque, and clutch oil pressure, determine the drive motor target torque during series-parallel switching, and update the value of the current drive motor target torque; Among them, the driver demand torque is obtained by looking up a table according to the vehicle speed and the accelerator pedal opening.

2. The series-parallel driving mode switching control method for a hybrid vehicle according to claim 1, wherein First, determine the smaller value between the absolute value of the maximum generator power generation torque and the maximum engine torque, and then determine the sum of the smaller value and the first preset torque value as the maximum available engine torque during series-parallel driving mode switching control; Determine the smaller value between the maximum available engine torque during series-parallel switching and the current engine target torque as the engine target torque during series-parallel driving mode switching control; If the current driving mode of the vehicle is a parallel driving mode, determine that the generator target torque during series-parallel switching is 0; If the current driving mode of the vehicle is a series driving mode, determine that the generator target torque during series-parallel switching is the actual generator torque.

3. The series-parallel drive mode switching control method for a hybrid vehicle according to claim 1 or 2, characterized in that The target drive mode includes a parallel drive mode. The relevant parameters of the vehicle include: the actual engine torque, the actual generator speed, the actual generator torque, the actual clutch oil pressure, the current target generator speed, and the engine target torque, the generator target torque, the drive motor target torque, and the target generator speed output by the vehicle's torque distribution module in the parallel drive mode. If the target drive mode is the parallel drive mode, according to the relevant parameters of the vehicle, the current drive mode, and the target drive mode, the steps for controlling the series-parallel drive mode switching of the vehicle include: Enter the generator speed synchronization stage: Set the actual generator torque to the target generator torque, and gradually adjust the current target generator speed to the target generator synchronization speed; If the absolute value of the difference between the target generator synchronization speed and the actual generator speed is less than the first preset speed value during the generator speed synchronization stage, enter the clutch closing stage: Perform clutch closing control; If the actual clutch oil pressure is greater than or equal to the first preset oil pressure after completing the clutch closing control, enter the torque recovery stage: Then adjust the generator control mode from speed control to torque control, and correspondingly adjust the values of the engine target torque, the generator target torque, the drive motor target torque, and the target generator speed during series-parallel switching to the engine target torque, the generator target torque, the drive motor target torque, and the target generator speed output by the vehicle's torque distribution module in the parallel drive mode.

4. The series-parallel drive mode switching control method for a hybrid vehicle according to claim 3, characterized in that The relevant parameters of the vehicle include: vehicle speed, generator-to-wheel speed ratio, and tire diameter; among them, the target generator synchronization speed is obtained through the formula: Calculated, where VehSpd is the vehicle speed, P1Ratio is the generator-to-wheel speed ratio, and D is the tire diameter.

5. The series-parallel drive mode switching control method for a hybrid vehicle according to claim 1 or 2, characterized in that The relevant parameters of the vehicle include: the actual engine torque, the actual generator torque, the actual generator speed, the actual clutch oil pressure, the engine-to-generator speed ratio, and the engine target torque, the generator target torque, the drive motor target torque, and the target generator speed output by the vehicle's torque distribution module in the series drive mode. The target drive mode includes a series drive mode. If the target drive mode is the series drive mode, according to the relevant parameters of the vehicle, the current drive mode, and the target drive mode, the steps for controlling the series-parallel drive mode switching of the vehicle include: Enter the torque exchange stage: Gradually increase 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, 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 during series-parallel switching; If the absolute value of the sum of the actual engine torque and the actual generator torque is less than or equal to the sixth preset torque value during the torque exchange stage, enter the clutch disconnection stage: Perform clutch disconnection control; After the clutch disconnection control is completed, if the actual clutch oil pressure is less than or equal to the second preset oil pressure, during the rotational speed and torque recovery stage: the generator mode control is adjusted from torque control to rotational speed control, and the values of the engine target torque, generator target torque, drive motor target torque, and generator target rotational speed during series-parallel switching are respectively adjusted to the engine target torque, generator target torque, drive motor target torque, and generator target rotational speed output by the vehicle's torque distribution module in the series drive mode.

6. The series-parallel drive mode switching control method for a hybrid vehicle according to claim 3 or 5, characterized in that, After the values of the engine target torque, generator target torque, drive motor target torque, and generator target rotational speed are adjusted, the method further includes: If the absolute value of the difference between the engine target torque output by the vehicle's torque distribution module in the parallel drive mode and the actual engine torque is less than or equal to the second preset torque value, the absolute value of the difference between the generator target torque output by the vehicle's torque distribution module in the parallel drive mode and the actual generator torque is less than or equal to the third preset torque value, and the absolute value of the difference between the drive motor target torque output by the vehicle's torque distribution module in the parallel drive mode and the actual drive motor torque is less than or equal to the fourth preset torque value, it is determined that the vehicle has completed the switch from the series drive mode to the parallel drive mode.

7. The series-parallel drive mode switching control method for a hybrid vehicle according to claim 1, wherein The drive motor target torque P3TqReq during series-parallel switching is calculated by the formula: P3TqReq = {DrvTqReq / P3Ratio - (EngTqAct*EngP1Ratio + P1TqAct) / abs(EngTqAct*EngP1Ratio + P1TqAct)*min[abs(EngTqAct*EngP1Ratio + P1TqAct), CluCarryTq]*P1P3Ratio} where DrvTqReq is the driver demand torque, obtained by looking up a table according to the vehicle speed and throttle 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 generator torque, P1P3Ratio is the speed ratio from the generator to the drive motor, and CluCarryTq is the clutch transmissible torque, obtained by looking up the clutch transmissible torque CluCarryTq from the clutch oil pressure characteristic curve representing the relationship between the actual clutch oil pressure and the clutch transmissible torque CluCarryTq.

8. The series-parallel drive mode switching control method for a hybrid vehicle according to claim 5, wherein After the engine target torque, generator target torque, drive motor target torque, and generator target rotational speed are adjusted, the method further includes: If the absolute value of the difference between the target engine torque and the actual engine torque output by the torque distribution module of the vehicle in the series drive mode is less than or equal to the eighth preset torque value, the absolute value of the difference between the target generator speed and the actual generator speed output by the torque distribution module of the vehicle in the series drive mode is less than or equal to the eighth preset torque value, and the absolute value of the difference between the target drive motor torque and the actual drive motor torque output by the torque distribution module of the vehicle in the series drive mode is less than or equal to the ninth preset torque value, it is determined that the vehicle has completed the switch from the parallel drive mode to the series drive mode.

9. A series-parallel drive mode switching control device for a hybrid vehicle, characterized in that, The hybrid system of the hybrid vehicle at least includes: a power battery, an engine, a drive motor, a generator, and a clutch. The engine can be coupled 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. The generator is connected to the power battery and / or the drive motor. The device includes: A parameter reading module, configured to read the relevant parameters of the vehicle and the current drive 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 generator, and the drive motor based on the current drive mode of the vehicle and the relevant parameters of the vehicle. A target drive mode recognition module, configured to recognize the target drive mode of the vehicle based on the received series-parallel switching request. A drive mode switching control module, configured to perform series-parallel drive mode switching control of the vehicle based on the relevant parameters of the vehicle, the current drive mode, and the target drive mode after completing the torque preprocessing. The relevant parameters of the vehicle include: 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 power generation 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: An engine maximum available torque determination unit, configured to determine the maximum available torque of the engine during series-parallel switching based on the maximum generator power generation torque and the maximum engine torque. An engine and generator target torque determination unit, configured to determine the target torque of the engine and the target torque of the generator during series-parallel switching based on the current drive mode of the vehicle, the maximum available torque of the engine during series-parallel switching, and the current engine target torque. An engine and generator target torque value update unit, configured to update the value of the current engine target torque and the value of the current generator target torque based on the current drive mode of the vehicle, the target torque of the engine during series-parallel switching, and the target torque of the generator during series-parallel switching. A driving motor target torque determination and value update unit, which is used to determine the driving motor target torque during series-parallel switching based on the driver's required torque, the speed ratio from the driving motor to the wheel end, the speed ratio from the engine to the generator, the speed ratio from the generator to the driving motor, the actual engine torque, the actual generator torque, and the clutch oil pressure, and update the value of the current driving motor target torque; Among them, the driver's required torque is obtained by looking up a table according to the vehicle speed and the throttle pedal opening.

10. The series-parallel drive mode switching control device for a hybrid vehicle according to claim 9, characterized in that, The target driving mode includes a parallel driving mode. The relevant parameters of the vehicle include: the actual engine torque, the actual generator speed, the actual generator torque, the actual clutch oil pressure, the current generator target speed, and the engine target torque, generator target torque, driving 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: A generator speed synchronization unit, which 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 synchronization speed; A clutch closing unit, which is used to enter the clutch closing stage if the absolute value of the difference between the generator synchronization target speed and the actual generator speed is less than the first preset speed value during the generator speed synchronization stage: perform clutch closing control; A torque recovery unit, which 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 the clutch closing control is completed: adjust the generator control mode from speed control to torque control, and correspondingly adjust the values of the engine target torque, generator target torque, driving motor target torque, and generator target speed during series-parallel switching to the engine target torque, generator target torque, driving motor target torque, and generator target speed output by the vehicle's torque distribution module in the parallel driving mode.

11. The series-parallel drive mode switching control device for a hybrid vehicle according to claim 9, wherein The relevant parameters of the vehicle include: the actual engine torque, the actual generator torque, the actual generator speed, the actual clutch oil pressure, the speed ratio from the engine to the generator, and the engine target torque, generator target torque, driving motor target torque, and generator target speed output by the vehicle's torque distribution module in the series driving mode. The target driving mode includes a series driving mode. If the target driving mode is the series driving mode, the driving mode switching control module includes: a torque exchange unit, which is used to enter the torque exchange stage: gradually increase 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 speed ratio from the engine to the generator, and at the same time adjust the driving motor target torque to follow the change to meet the driver's required torque; set the actual generator speed to the generator target speed during series-parallel switching; A clutch disconnection unit, which is used to enter the clutch disconnection stage if the absolute value of the sum of the actual engine torque and the actual generator torque is less than or equal to the sixth preset torque value during the torque exchange stage: perform clutch disconnection control; A rotational speed and torque recovery unit, which is used to, after the clutch disconnection control is completed, if the actual oil pressure of the clutch is less than or equal to the second preset oil pressure, during the rotational speed and torque recovery stage: adjust the generator mode control from torque control to rotational speed control, and adjust the values of the engine target torque, generator target torque, drive motor target torque, and generator target rotational speed during series-parallel switching to the engine target torque, generator target torque, drive motor target torque, and generator target rotational speed output by the torque distribution module of the vehicle in the series drive mode respectively.

12. A vehicle, characterized in that, It includes the series-parallel drive mode switching control device of the hybrid vehicle according to any one of claims 9 to 11.

13. A control device, characterized in that, It includes a processor, a memory, and a program or instruction stored on 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 of the hybrid vehicle according to any one of claims 1 to 8 are implemented.

14. A readable storage medium, characterized in that, A program or instruction is stored on the readable storage medium. 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 according to any one of claims 1 to 8 are implemented.

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