Engine control method for hybrid vehicle, medium, controller and vehicle

Abstract

An engine control method for a hybrid vehicle comprises: in response to a shutdown requirement of an engine, controlling the engine to perform torque reduction, and using an ISG motor to stabilize the rotating speed of the engine at the minimum idling power generation rotating speed; and when the torque of the engine is reduced to zero and the rotating speed of the engine is stabilized at the minimum idling power generation rotating speed for a first preset time, controlling the ISG motor to drag-stop the engine.

Description

Hybrid vehicle engine control method, medium, controller, and vehicle

[0001] Priority information

[0002] This application claims priority and benefits of patent application No. 2024102201282 filed with the State Intellectual Property Office of China on February 28, 2024, and the entire text of which is incorporated herein by reference. Technical Field

[0003] The present application relates to the field of engine control, and in particular to an engine control method, medium, controller, and vehicle for a hybrid vehicle. Background Art

[0004] The related engine shutdown control technology uses the engine control unit to perform closed-loop control of the engine speed, which has the disadvantages of slow speed convergence, long shutdown time, inability to quickly reach the target speed, and limited adjustment range.

[0005] Summary of the Invention

[0006] The present application aims to at least partially address one of the technical problems in the related art. To this end, one object of the present application is to provide an engine control method for a hybrid vehicle, which has the advantages of rapid engine speed control response before shutdown, controllable engine speed changes during shutdown, and stable system state.

[0007] A second object of the present application is to provide a computer-readable storage medium.

[0008] The third objective of this application is to provide a controller.

[0009] A fourth objective of the present application is to provide a hybrid vehicle.

[0010] To achieve the above-mentioned purpose, the first aspect embodiment of the present application proposes an engine control method for a hybrid vehicle, wherein the hybrid vehicle includes an engine and an ISG motor, and the method includes: in response to the shutdown requirement of the engine, controlling the engine to reduce the torque, and using the ISG motor to stabilize the speed of the engine at the idle minimum power generation speed; when the torque of the engine is reduced to zero and the time for the engine speed to stabilize at the idle minimum power generation speed reaches a first preset time, controlling the ISG motor to stop the engine.

[0011] According to the engine control method of the hybrid vehicle in the embodiment of the present application, the engine torque reduction control is performed while the ISG motor is used to control the engine speed, thereby accelerating the convergence of the engine speed before shutdown, and when the engine torque is reduced to zero, the ISG motor controls the engine speed, thereby ensuring a rapid response of the engine speed control before shutdown, controllable engine speed changes during shutdown, and stable system status.

[0012] In addition, the engine control method for a hybrid vehicle according to the above embodiment of the present application may also have the following additional technical features:

[0013] According to one embodiment of the present application, the engine is controlled to reduce torque, and the engine speed is adjusted to the idle minimum power generation speed by using the ISG motor, including: determining the idle target indicated torque and the idle minimum power generation speed; controlling the torque of the engine to reduce to the idle target indicated torque, and controlling the ISG motor according to the real-time speed of the engine to stabilize the engine speed at the idle minimum power generation speed; when the time when the engine speed is stabilized at the idle minimum power generation speed reaches a second preset time, controlling the engine torque to reduce from the idle target indicated torque to zero, and controlling the ISG motor to increase torque, so that the time when the engine speed is stabilized at the idle minimum power generation speed reaches a first preset time.

[0014] According to one embodiment of the present application, the method further includes: controlling the pressure in the cylinder of the engine when the torque of the engine is reduced to zero.

[0015] According to an embodiment of the present application, determining the idle target indicated torque includes: determining the idle target indicated torque according to the engine speed and coolant temperature before responding to the engine shutdown request.

[0016] According to one embodiment of the present application, determining the idle minimum power generation speed includes: determining the idle minimum power generation speed based on the smaller value of the engine speed before responding to the engine shutdown requirement and the idle shutdown maximum speed.

[0017] According to one embodiment of the present application, controlling the pressure in the cylinder of the engine includes: controlling the engine to prohibit fuel injection and closing the throttle of the engine.

[0018] According to one embodiment of the present application, the method further includes: prohibiting ignition of the engine.

[0019] According to one embodiment of the present application, controlling the ISG motor according to the real-time speed of the engine to stabilize the speed of the engine at the idle minimum power generation speed includes: calculating the difference between the real-time speed of the engine and the idle minimum power generation speed; controlling the ISG motor according to the difference to stabilize the speed of the engine at the idle minimum power generation speed.

[0020] According to one embodiment of the present application, in the process of controlling the ISG motor according to the real-time speed of the engine to stabilize the speed of the engine at the idle minimum power generation speed, the method further includes: if the real-time speed of the engine is less than the minimum preset speed, reducing the output torque of the ISG motor; if the real-time speed of the engine is greater than or equal to the minimum preset speed and less than the idle minimum power generation speed, executing the step of controlling the ISG motor to stop the engine.

[0021] According to one embodiment of the present application, controlling the torque increase of the ISG motor includes: reducing the slope of loading or unloading of the output torque of the ISG motor in the target torque range according to the idle minimum power generation speed.

[0022] According to one embodiment of the present application, the method further includes: in the process of controlling the torque increase of the ISG motor to stabilize the speed of the engine at the idle minimum power generation speed, when the speed of the engine fluctuates, the output torque of the ISG motor is unidirectionally limited.

[0023] To achieve the above-mentioned purpose, the second embodiment of the present application proposes a computer-readable storage medium on which a computer program is stored. When the computer program is executed by a processor, the engine control method of a hybrid vehicle proposed in the first embodiment of the present application is implemented.

[0024] To achieve the above-mentioned purpose, the third embodiment of the present application proposes a controller, including a memory and a processor, wherein a computer program is stored in the memory. When the computer program is executed by the processor, the engine control method of the hybrid vehicle proposed in the first embodiment of the present application is implemented.

[0025] To achieve the above-mentioned objectives, the fourth embodiment of the present application proposes a hybrid vehicle, comprising: an engine, an ISG motor and a controller as proposed in the third embodiment of the present application.

[0026] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] FIG1 is a flow chart of an engine control method for a hybrid vehicle according to an embodiment of the present application;

[0028] FIG2 is a flow chart of adjusting the engine speed to the idle minimum power generation speed according to one embodiment of the present application;

[0029] FIG3 is a flow chart of an engine control method for a hybrid vehicle according to a specific embodiment of the present application;

[0030] FIG4 is a block diagram of a controller according to an embodiment of the present application;

[0031] FIG5 is a schematic diagram of a hybrid vehicle according to an embodiment of the present application. DETAILED DESCRIPTION

[0032] The following describes in detail embodiments of the present application, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limiting the present application.

[0033] The engine control method and medium, controller 500, and vehicle 1000 of the hybrid vehicle according to the embodiment of the present application are described in detail below with reference to Figures 1-5 of the specification and specific implementation methods.

[0034] In the embodiment of the present application, the hybrid vehicle 1000 may include an engine 100 and an ISG (Integrated Starter and Generate motor) motor 300 .

[0035] FIG1 is a flow chart of an engine control method for a hybrid vehicle according to an embodiment of the present invention. As shown in FIG1 , the engine control method for a hybrid vehicle may include:

[0036] S101, in response to a shutdown request of the engine 100, controlling the engine 100 to reduce torque, and utilizing the ISG motor 300 to stabilize the speed of the engine 100 at the minimum idle power generation speed;

[0037] S102 , when the torque of the engine 100 is reduced to zero and the time during which the speed of the engine 100 is stabilized at the idle minimum power generation speed reaches a first preset time, the ISG motor 300 is controlled to stop the engine 100 .

[0038] For example, when the target operating mode of the engine 100 is switched from the parallel / series operating mode to the shutdown operating mode, or when it is determined that the engine 100 needs to be shut down based on the state of charge (SOC), discharge power, driving demand power, etc. of the power battery, the engine 100 is shut down.

[0039] The embodiment of the present application uses a power domain controller to control the engine controller (Engine Control Module, ECM) and the ISG motor 300 to complete the shutdown control of the engine 100.

[0040] In the embodiment of the present application, the power domain controller may be a powertrain control module (PCM), a vehicle control unit (VCU), an electronic control unit (ECU), or the like.

[0041] In the embodiment of the present application, when the engine 100 is shut down, in order to accelerate the convergence of the engine 100 speed, the PCM controls the ECM to reduce the torque of the engine 100 and reduce the speed of the engine 100, while also controlling the output torque of the ISG motor 300. That is, the speed of the engine 100 is controlled jointly by the ECM and the ISG motor 300 to quickly adjust the speed of the engine 100 to the idle minimum power generation speed and stabilize it at the idle minimum power generation speed. When the PCM controls the ECM to reduce the torque of the engine 100 and reduces the torque of the engine 100 to zero, the ISG motor 300 independently controls the speed of the engine 100, and when the time for the engine 100 speed to stabilize at the idle minimum power generation speed reaches the first preset time N1, the ISG motor 300 is controlled to stop the engine 100, thereby ensuring the stability of the system state before shutdown.

[0042] In an embodiment of the present application, when controlling the ISG motor 300 to stop the engine 100, the target speed of the ISG motor 300 can be changed to 0 rpm (revolutions per minute) so that the speed of the engine 100 can be dragged back to 0 rpm to stop by outputting feedback torque through the ISG motor 300.

[0043] In one embodiment of the present application, as shown in FIG2 , controlling the engine 100 to reduce torque and using the ISG motor 300 to stabilize the speed of the engine 100 at the idle minimum power generation speed may include:

[0044] S201, determining an idle target indicated torque and an idle minimum generating speed;

[0045] S202 , controlling the torque of the engine 100 to decrease to the idle target indicated torque, and controlling the ISG motor 300 according to the real-time speed of the engine 100 to stabilize the speed of the engine 100 at the idle minimum generating speed;

[0046] S203, when the time when the speed of the engine 100 is stabilized at the idle minimum power generation speed reaches the second preset time, the torque of the engine 100 is controlled to drop from the idle target indicated torque to zero, and the ISG motor 300 is controlled to increase the torque so that the speed of the engine 100 is stabilized at the idle minimum power generation speed for the first preset time.

[0047] Specifically, after the PCM determines the idle target indicated torque T1 and the idle minimum power generation speed, it sends the idle target indicated torque T1 to the ECM. In response to the idle target indicated torque T1 sent by the PCM, the ECM controls the torque of the engine 100 to be reduced to the idle target indicated torque T1. While sending the idle target indicated torque T1 to the ECM, the PCM also sends the idle minimum power generation speed to the ISG motor 300. This controls the ECM to reduce the engine 100 torque while controlling the ISG output load torque based on the real-time engine 100 speed and the idle minimum power generation speed. The ECM and ISG motor 300 jointly adjust the engine 100 speed, allowing the engine 100 speed to be quickly adjusted to the idle minimum power generation speed.

[0048] The embodiment of the present application quickly adjusts the speed of the engine 100 to the idle minimum power generation speed and stabilizes it at the idle minimum power generation speed by feedforward adjusting the torque of the engine 100 and feedback adjusting the torque of the ISG motor 300, thereby achieving rapid convergence of the engine 100 speed.

[0049] When the engine 100 speed remains stable at the idle minimum generating speed for a second predetermined time N2, the PCM decays the target indicated torque T1 to zero at a predetermined rate. The ECM controls the engine 100 torque to decrease from the idle target indicated torque T1 to zero torque. Simultaneously, the ISG motor 300 is controlled to begin a step-by-step torque increase. This transitions from joint control of the engine 100 speed by the ECM and ISG motor 300 to independent control of the engine 100 speed by the ISG, stabilizing the engine 100 speed at the idle minimum generating speed.

[0050] Before controlling the engine 100 to shut down, the embodiment of the present application coordinates the speed of the engine 100 through the ECM and the ISG motor 300, and the speed transition of the engine 100 is jointly controlled by the ISG motor 300 and the ECM, and the speed of the engine 100 is controlled solely by the ISG, thereby ensuring that the system state is stable before shutdown.

[0051] In one embodiment of the present application, determining the idle target indicated torque may include:

[0052] The idle target indicated torque is determined based on the speed of engine 100 and the coolant temperature before responding to the stop request of engine 100 .

[0053] Specifically, the PCM may determine the idle target indicated torque T1 based on the speed of the engine 100 and the coolant temperature before responding to the shutdown request of the engine 100 using a table lookup method, and send the idle target indicated torque T1 to the ECM.

[0054] In the embodiment of the present application, the engine 100 speed and coolant temperature are used to look up the system resistance torque of the engine 100 as a feedforward link.

[0055] In one embodiment of the present application, determining the minimum idle power generation speed may include:

[0056] The idle minimum power generation speed is determined based on the smaller value of the speed of the engine 100 before responding to the stop request of the engine 100 and the idle stop maximum speed.

[0057] Specifically, the PCM takes the smaller value between the engine speed before responding to the shutdown request of the engine 100 and the idle shutdown maximum speed, uses the smaller value as the idle minimum power generation speed, and sends the idle minimum power generation speed to the ISG motor 300.

[0058] In one embodiment of the present application, controlling the ISG motor 300 according to the real-time speed of the engine 100 to stabilize the speed of the engine 100 at the idle minimum power generation speed may include:

[0059] Calculating the difference between the real-time speed of the engine 100 and the idle minimum power generation speed;

[0060] The ISG motor 300 is controlled according to the difference to stabilize the rotation speed of the engine 100 at the idle minimum power generation speed.

[0061] Specifically, the difference between the real-time speed of the engine 100 and the idle minimum power generation speed is calculated, and based on the calculated difference, the ISG torque is output for feedback control to stabilize the speed of the engine 100 at the idle minimum power generation speed.

[0062] The embodiment of the present application controls the ISG motor 300 to perform closed-loop coordinated control on the speed of the engine 100, and close-loop adjusts the speed of the engine 100 to the minimum idle power generation speed.

[0063] In one embodiment of the present application, in the process of controlling the ISG motor 300 according to the real-time speed of the engine 100 to stabilize the speed of the engine 100 at the idle minimum power generation speed, the engine control method of the hybrid vehicle may further include:

[0064] If the real-time speed of the engine 100 is less than the minimum preset speed, the output torque of the ISG motor 300 is reduced;

[0065] If the real-time speed of the engine 100 is greater than or equal to the lowest preset speed and less than the idle minimum power generation speed, the step of controlling the ISG motor 300 to stop the engine 100 is executed.

[0066] Specifically, the ISG motor 300 is controlled based on the real-time speed of the engine 100 to stabilize the speed of the engine 100 at the minimum idle power generation speed. If the speed of the engine 100 falls below the minimum set speed during the adjustment process, the output torque of the ISG motor 300 is controlled to be reduced to prevent excessive load torque on the engine 100, which could cause the engine 100 to stall. If the output torque of the ISG motor 300 is reduced to 0 and the speed of the engine 100 is still below the minimum set speed, the ISG motor 300 is controlled to shut down the engine 100. If the real-time speed of the engine 100 is greater than or equal to the minimum set speed and less than the minimum idle power generation speed, the ISG motor 300 is controlled to shut down the engine 100.

[0067] In an embodiment of the present application, the minimum preset rotation speed may be 500 rpm-800 rpm.

[0068] In one embodiment of the present application, the engine control method of a hybrid vehicle further includes:

[0069] When the torque of the engine 100 is reduced to zero, the pressure in the cylinder of the engine 100 is controlled.

[0070] Specifically, when the torque of the engine 100 is reduced to zero, the PCM controls the ECM to control the pressure in the cylinder of the engine 100, so that the pressure in the cylinder of the engine 100 is controlled, thereby avoiding abnormal knocking noise during the shutdown process.

[0071] In one embodiment of the present application, controlling the pressure in the cylinder of the engine 100 includes: controlling the engine 100 to prohibit fuel injection and closing the throttle of the engine 100 .

[0072] Specifically, when the torque of the engine 100 is unloaded to zero, the engine 100 is controlled to prohibit fuel injection and close the throttle of the engine 100 .

[0073] In practice, the PCM controls the ECM to execute the throttle closing action and sends a fuel injection prohibition instruction to the ECM. In response to the fuel injection prohibition instruction, the ECM controls the engine 100 to prohibit fuel injection. It should be noted that the engine 100 prohibits fuel injection but does not stop ignition.

[0074] Before controlling the engine 100 to shut down, the embodiment of the present application controls the throttle of the engine 100 to close, so that the pressure in the cylinder can be controlled, suppressing excessive torsional vibration and reverse rotation of the shut-down engine 100, and avoiding problems such as gear pair knocking caused by the reverse rotation of the engine 100.

[0075] In one embodiment of the present application, the engine control method for a hybrid vehicle further includes: prohibiting ignition of the engine 100 .

[0076] Specifically, the PCM sends a stop command, and the ECM responds to the stop command by controlling ignition enable prohibition to prohibit ignition of the engine 100 .

[0077] In one embodiment of the present application, controlling the torque of the ISG motor 300 may include:

[0078] According to the idle minimum power generation speed, the slope of loading or unloading of the output torque of the ISG motor 300 is reduced in the target torque range.

[0079] Specifically, while controlling the torque of the engine 100 to decrease from the idle target indicated torque T1 to zero torque, the slope of loading or unloading the output torque of the ISG motor 300 is reduced in the target torque range according to the idle minimum power generation speed.

[0080] In one embodiment of the present application, the engine control method of a hybrid vehicle further includes:

[0081] In the process of controlling the torque increase of the ISG motor 300 to stabilize the speed of the engine 100 at the idle minimum power generation speed, when the speed of the engine 100 fluctuates, the output torque of the ISG motor 300 is unidirectionally limited.

[0082] Specifically, when controlling the torque increase of the ISG motor 300 to stabilize the engine 100 speed at the minimum idle power generation speed, if the engine 100 speed fluctuates, the output torque of the ISG motor 300 is unidirectionally limited. That is, the positive or negative value of the output torque of the ISG motor 300 at the previous moment is determined based on the positive or negative value of the output torque of the ISG motor 300, thereby preventing gear rattle caused by frequent changes in the ISG torque exceeding zero.

[0083] As a specific embodiment, as shown in FIG3 , the PCM sends the idle target indicated torque T1 to the ECM and starts timing Time1. The PCM performs a smaller cutoff between the speed of the engine 100 before responding to the shutdown request of the engine 100 and the idle shutdown maximum speed, and sends the idle minimum power generation speed to the ISG motor 300. The PCM compares the real-time speed of the engine 100 with the idle minimum power generation speed, and calculates the ISG speed adjustment torque based on the difference obtained from the comparison, which is then executed by the ISG. If the speed of the engine 100 is less than the minimum set speed during the adjustment process, the ISG adjustment torque is reduced to prevent the engine 100 load torque from being too large, causing the engine 100 to stall. If the speed of the engine 100 is greater than or equal to the minimum set speed and less than the idle minimum power generation speed, the ISG motor 300 is controlled to pull the engine 100 to stop. When timer Time1 is reached (it should be noted that reaching timer Time1 allows the engine 100 speed to stabilize at the idle minimum generating speed for a second predetermined time N2, i.e., Time1>N2), the PCM decays target indicated torque T1 at a predetermined rate and begins timer Time2. As ISG torque begins to decay at target indicated torque T1, it is further adjusted based on the idle minimum generating speed, reducing the slope of ISG torque loading or unloading within the torque range [-T_isg, T_isg]. When engine 100 torque drops to zero, the PCM controls the ECM to close the throttle and sends a fuel injection disable command to the ECM. In response to the fuel injection disable command, the ECM controls engine 100 to disable fuel injection. When timer Time2 is reached (it should be noted that reaching timer Time2 allows the engine 100 speed to stabilize at the idle minimum generating speed for a first predetermined time N1, i.e., Time2>N1), the ISG motor 300 is controlled to stop the engine 100.

[0084] The engine control method of the hybrid vehicle in the embodiment of the present application coordinates control between the ISG and the engine 100, so that the speed and moment of inertia of the engine 100 before shutdown have high consistency; controlling the throttle valve to close before shutdown can suppress excessive torsional vibration and reversal of the stopped engine 100, avoiding problems such as gear pair knocking caused by the reversal of the engine 100.

[0085] The engine control method of the hybrid vehicle in the embodiment of the present application adopts a feedforward plus feedback adjustment method to quickly stabilize the speed of the engine 100. The speed control before shutdown is changed from being jointly controlled by the ISG and the ECM to being controlled solely by the ISG, ensuring that the system state is stable before shutdown. Before shutdown, the throttle is closed and fuel injection is prohibited so that the pressure in the cylinder can be controlled, avoiding knocking noises during the shutdown process.

[0086] It should be noted that hybrid vehicles 1000 often use an ISG motor 300 for starting. For hybrid vehicles 1000 with dual motors in series-parallel or range-extended configurations, the engine 100 and generator are rigidly connected via a gear pair and torque damper, and the generator inertia is much greater than in traditional vehicles 1000 with a starter. The engine 100 speed and load torque stability, as well as the cylinder pressure, in the initial shutdown state significantly affect the shutdown NVH (Noise, Vibration, Harshness) quality. Using the control method of the present embodiment can also improve the shutdown NVH quality of hybrid vehicles 1000.

[0087] The present application provides a computer-readable storage medium.

[0088] In this embodiment, a computer program is stored on a computer-readable storage medium. When the computer program is executed by a processor, the engine control method of a hybrid vehicle as described above is implemented.

[0089] The present application provides a controller 500 .

[0090] In this embodiment, the controller 500 may include a memory and a processor. The memory stores a computer program. When the computer program is executed by the processor, the engine control method of the hybrid vehicle as described above is implemented.

[0091] FIG4 is a structural block diagram of the controller 500 according to an embodiment of the present application.

[0092] As shown in Figure 4, controller 500 includes a processor 501 and a memory 503. Processor 501 and memory 503 are connected, for example, via a bus 502. Optionally, controller 500 may also include a transceiver 504. It should be noted that in practical applications, there is not limited to one transceiver 504, and the structure of controller 500 does not constitute a limitation on the embodiments of this application.

[0093] The processor 501 may be a CPU (Central Processing Unit), a general-purpose processor, a DSP (Digital Signal Processor), an ASIC (Application Specific Integrated Circuit), an FPGA (Field Programmable Gate Array), or other programmable logic devices, transistor logic devices, hardware components, or any combination thereof. It may implement or execute the various exemplary logic blocks, modules, and circuits described in conjunction with the disclosure of this application. The processor 501 may also be a combination that implements computing functions, such as a combination of one or more microprocessors, a combination of a DSP and a microprocessor, and the like.

[0094] Bus 502 may include a path for transmitting information between the aforementioned components. Bus 502 may be a PCI (Peripheral Component Interconnect) bus or an EISA (Extended Industry Standard Architecture) bus, for example. Bus 502 may be divided into an address bus, a data bus, a control bus, and so on. For ease of illustration, FIG4 shows only one thick line, but this does not indicate that there is only one bus or only one type of bus.

[0095] The memory 503 is used to store a computer program corresponding to the hybrid vehicle engine control method of the above embodiment of the present application, and the computer program is controlled and executed by the processor 501. The processor 501 is used to execute the computer program stored in the memory 503 to implement the content shown in the above method embodiment.

[0096] The controller 500 includes, but is not limited to, mobile terminals such as mobile phones, laptop computers, digital broadcast receivers, PDAs (personal digital assistants), PADs (tablet computers), PMPs (portable multimedia players), and in-vehicle terminals (e.g., in-vehicle navigation terminals), as well as fixed terminals such as digital TVs and desktop computers. The controller 500 shown in FIG4 is merely an example and should not limit the functionality and scope of use of the embodiments of the present application.

[0097] The computer-readable storage medium and controller 500 of the embodiment of the present application utilize the engine control method of the hybrid vehicle mentioned above to ensure that the speed control response of the engine 100 before shutdown is fast and the system state is stable, so that the speed change of the engine 100 during shutdown is controllable, and abnormal knocking noise is avoided during the shutdown process.

[0098] The present application provides a hybrid vehicle 1000 .

[0099] Fig. 5 is a schematic diagram of a hybrid vehicle 1000 according to an embodiment of the present application. As shown in Fig. 5 , the hybrid vehicle 1000 may include: an engine 100, an ISG motor 300, and a controller 500 as described above.

[0100] It should be noted that the controller 500 is a power domain controller, which can be exemplified by a PCM, a VCU, an ECU, etc.

[0101] The hybrid vehicle 1000 of the embodiment of the present application ensures a rapid response of the engine 100 speed control before shutdown and a stable system state, so that the engine 100 speed change during shutdown is controllable and abnormal knocking noise is avoided during the shutdown process.

[0102] It should be noted that the logic and / or steps represented in the flowcharts or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing the logical functions, and can be embodied in any computer-readable medium for use by an instruction execution system, apparatus, or device (such as a computer-based system, a system including a processor, or other system that can fetch and execute instructions from an instruction execution system, apparatus, or device), or in conjunction with such instruction execution system, apparatus, or device. For the purposes of this specification, a "computer-readable medium" can be any device that can contain, store, communicate, propagate, or transmit a program for use by an instruction execution system, apparatus, or device, or in conjunction with such instruction execution system, apparatus, or device. More specific examples (non-exhaustive list) of computer-readable media include the following: an electrical connection portion having one or more wires (electronic device), a portable computer disk cartridge (magnetic device), random access memory (RAM), read-only memory (ROM), erasable and programmable read-only memory (EPROM or flash memory), fiber optic devices, and portable compact disc read-only memory (CDROM). Furthermore, the computer-readable medium may even be paper or other suitable medium on which the program is printed, since the program may be obtained electronically, for example, by optically scanning the paper or other medium and then editing, interpreting or processing it in another suitable manner if necessary, and then storing it in a computer memory.

[0103] It should be understood that various parts of the present application can be implemented using hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented using software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented using hardware, as in another embodiment, any one of the following technologies known in the art or a combination thereof can be used to implement: a discrete logic circuit having a logic gate circuit for implementing a logic function on a data signal, an application-specific integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0104] Throughout this specification, reference to terms such as "one embodiment," "some embodiments," "examples," "specific examples," or "some examples" means that a specific feature, structure, material, or characteristic described in conjunction with that embodiment or example is included in at least one embodiment or example of the present application. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0105] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0106] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of such features. Throughout the description of this application, "plurality" means at least two, for example, two, three, etc., unless otherwise specifically defined.

[0107] In this application, unless otherwise specified or limited, the terms "installed," "connected," "connect," "fixed," etc. should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; internal communication between two elements or interaction between two elements, unless otherwise specified. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0108] In this application, unless otherwise expressly specified or limited, when a first feature is "above" or "below" a second feature, it may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Furthermore, when a first feature is "above," "above," or "above" a second feature, it may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. When a first feature is "below," "below," or "below" a second feature, it may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0109] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A method for controlling an engine of a hybrid vehicle, wherein: The hybrid vehicle (1000) comprises an engine (100) and an ISG motor (300), and the method comprises: In response to a shutdown requirement of the engine (100), the engine (100) is controlled to reduce torque, and the rotation speed of the engine (100) is stabilized at an idle minimum power generation speed by using the ISG motor (300); When the torque of the engine (100) is reduced to zero and the time during which the rotation speed of the engine (100) is stabilized at the idle minimum power generation rotation speed reaches a first preset time, the ISG motor (300) is controlled to stop the engine (100).

2. The hybrid vehicle engine control method according to claim 1, wherein: The controlling of the engine (100) to reduce torque and stabilizing the rotation speed of the engine (100) at an idle minimum power generation speed by using the ISG motor (300) comprises: Determine the idle target indicated torque and the idle minimum generating speed; Controlling the torque of the engine (100) to decrease to the idle target indicated torque, and controlling the ISG motor (300) according to the real-time rotation speed of the engine (100) to stabilize the rotation speed of the engine (100) at the idle minimum power generation rotation speed; When the time for the rotation speed of the engine (100) to be stabilized at the idle minimum power generation speed reaches a second preset time, the torque of the engine (100) is controlled to decrease from the idle target indicated torque to zero, and the ISG motor (300) is controlled to increase the torque, so that the rotation speed of the engine (100) is stabilized at the idle minimum power generation speed until the time reaches a first preset time.

3. The hybrid vehicle engine control method according to claim 1, wherein: The method further comprises: When the torque of the engine (100) is reduced to zero, the pressure in the cylinder of the engine (100) is controlled.

4. The engine control method for a hybrid vehicle according to claim 2, wherein: Determining the idle target indicated torque includes: The idle target indicated torque is determined based on the rotational speed and coolant temperature of the engine (100) before responding to a shutdown request of the engine (100).

5. The engine control method for a hybrid vehicle according to claim 2, wherein: Determining the idle minimum generating speed includes: The idle minimum power generation speed is determined according to the smaller value of the speed of the engine (100) before responding to the shutdown requirement of the engine (100) and the idle shutdown maximum speed.

6. The engine control method for a hybrid vehicle according to claim 3, wherein: The controlling of the pressure in the cylinder of the engine (100) comprises: The engine (100) is controlled to prohibit fuel injection and close the throttle of the engine (100).

7. The engine control method for a hybrid vehicle according to claim 6, wherein: The method further comprises: Ignition of the engine (100) is inhibited.

8. The engine control method for a hybrid vehicle according to claim 2, wherein: The controlling of the ISG motor (300) according to the real-time rotation speed of the engine (100) to stabilize the rotation speed of the engine (100) at the idle minimum power generation speed comprises: Calculating the difference between the real-time rotation speed of the engine (100) and the idle minimum power generation rotation speed; The ISG motor (300) is controlled according to the difference to stabilize the rotation speed of the engine (100) at the idle minimum power generation rotation speed.

9. The hybrid vehicle engine control method according to claim 2, wherein: In the process of controlling the ISG motor (300) according to the real-time rotation speed of the engine (100) to stabilize the rotation speed of the engine (100) at the idle minimum power generation rotation speed, the method further comprises: If the real-time speed of the engine (100) is less than a minimum preset speed, reducing the output torque of the ISG motor (300); If the real-time speed of the engine (100) is greater than or equal to the lowest preset speed and less than the idle minimum power generation speed, the step of controlling the ISG motor (300) to stop the engine (100) is performed.

10. The engine control method for a hybrid vehicle according to claim 2, wherein: The controlling of the ISG motor (300) to increase torque comprises: According to the idle minimum power generation speed, the slope of loading or unloading of the output torque of the ISG motor (300) is reduced in the target torque range.

11. The engine control method for a hybrid vehicle according to claim 8, wherein: The method further comprises: In the process of controlling the torque increase of the ISG motor (300) to stabilize the rotation speed of the engine (100) at the idle minimum power generation rotation speed, when the rotation speed of the engine (100) fluctuates, the output torque of the ISG motor (300) is unidirectionally limited.

12. A computer-readable storage medium having a computer program stored thereon, wherein: When the computer program is executed by a processor, the method for controlling the engine (100) of the hybrid vehicle (1000) according to any one of claims 1 to 11 is implemented.

13. A controller (500), comprising a memory (503) and a processor (501), wherein the memory (503) stores a computer program, wherein: When the computer program is executed by the processor (501), the engine control method for a hybrid vehicle according to any one of claims 1 to 11 is implemented.

14. A hybrid vehicle (1000), wherein: include: An engine (100), an ISG motor (300), and a controller (500) as claimed in claim 13.

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