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

Abstract

The application discloses an engine control method and medium, controller and vehicle of a hybrid vehicle, the hybrid vehicle comprising an engine and an ISG motor, the method comprising: in response to a shutdown requirement of the engine, controlling the engine to reduce torque, and using the ISG motor to stabilize the rotating speed of the engine at an idle minimum power generation rotating speed; when the torque of the engine is reduced to zero, and the time for stabilizing the rotating speed of the engine at the idle minimum power generation rotating speed reaches a first preset time, controlling the ISG motor to pull the engine to a stop. The method has the advantages that the rotating speed control response of the engine before shutdown is fast, the rotating speed change of the engine during shutdown is controllable, and the system state is stable.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of engine control, in particular to an engine control method and medium, controller and vehicle of a hybrid vehicle. BACKGROUND

[0002] The related engine shutdown control technology, the engine speed is closed-loop controlled by the engine control unit, has the shortcomings of slow convergence of speed, long shutdown time, unable to quickly reach the target speed and limited adjustment range. SUMMARY

[0003] The present application aims to at least solve 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 of a hybrid vehicle, which has the advantages of fast response of engine speed control before shutdown, controllable engine speed change during shutdown, and stable system state.

[0004] A second object of the present application is to provide a computer-readable storage medium.

[0005] A third object of the present application is to provide a controller.

[0006] A fourth object of the present application is to provide a hybrid vehicle.

[0007] To achieve the above-mentioned objects, the first aspect of the present application provides an engine control method of a hybrid vehicle, the hybrid vehicle comprising an engine and an ISG motor, the method comprising: in response to a shutdown requirement of the engine, controlling the engine to reduce torque, and using the ISG motor to stabilize the engine speed at an 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.

[0008] According to the engine control method of the hybrid vehicle of the present application, the engine is controlled to reduce torque while the ISG motor is used to control the engine speed, which accelerates the convergence of the engine speed before shutdown, and when the engine torque is reduced to zero, the ISG motor is used to control the engine speed, which ensures fast response of engine speed control before shutdown, controllable engine speed change during shutdown, and stable system state.

[0009] In addition, the engine control method of the hybrid vehicle according to the above-mentioned embodiments of the present application can also have the following additional technical features:

[0010] According to one embodiment of the present application, the controlling the engine to reduce torque, and adjusting the engine speed of the engine to an idle minimum power generation speed by the ISG motor comprises: determining an idle target indicated torque and an 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 for stabilizing the engine speed at the idle minimum power generation speed reaches a second preset time, controlling the torque of the engine to reduce from the idle target indicated torque to zero, and controlling the ISG motor to increase torque to stabilize the engine speed at the idle minimum power generation speed when the time reaches a first preset time.

[0011] According to one embodiment of the present application, the method further comprises: controlling the pressure in the cylinder of the engine when the torque of the engine is reduced to zero.

[0012] According to one embodiment of the present application, the determining the idle target indicated torque comprises: determining the idle target indicated torque according to the engine speed and coolant temperature before the engine is required to stop.

[0013] According to one embodiment of the present application, the determining the idle minimum power generation speed comprises: determining the idle minimum power generation speed according to the smaller value of the engine speed and an idle stop maximum speed before the engine is required to stop.

[0014] According to one embodiment of the present application, the controlling the pressure in the cylinder of the engine comprises: controlling the engine to prohibit fuel injection and close the throttle valve of the engine.

[0015] According to one embodiment of the present application, the method further comprises: prohibiting ignition of the engine.

[0016] According to one embodiment of the present application, the 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 comprises: calculating the difference between the real-time speed of the engine and the idle minimum power generation speed; and controlling the ISG motor according to the difference to stabilize the engine speed at the idle minimum power generation speed.

[0017] According to one embodiment of the present application, in the process of controlling the ISG motor to increase the torque to stabilize the engine speed at the idle minimum power generation speed, the method further comprises: if the real-time engine speed is less than a minimum preset speed, reducing the output torque of the ISG motor; if the real-time engine speed is greater than or equal to the minimum preset speed and less than the idle minimum power generation speed, performing the step of controlling the ISG motor to pull the engine to stop.

[0018] According to one embodiment of the present application, the step of controlling the ISG motor to increase the torque comprises: according to the idle minimum power generation speed, reducing the slope of the load or unload of the output torque of the ISG motor in a target torque interval.

[0019] According to one embodiment of the present application, the method further comprises: in the process of controlling the ISG motor to increase the torque to stabilize the engine speed at the idle minimum power generation speed, when the engine speed fluctuates, unidirectionally limiting the output torque of the ISG motor.

[0020] To achieve the above object, a second aspect of the present application provides a computer readable storage medium, which stores a computer program, and the computer program is executed by a processor to implement the engine control method of the hybrid vehicle according to the first aspect of the present application.

[0021] To achieve the above object, a third aspect of the present application provides a controller, which comprises a memory and a processor, and the memory stores a computer program, and the computer program is executed by the processor to implement the engine control method of the hybrid vehicle according to the first aspect of the present application.

[0022] To achieve the above object, a fourth aspect of the present application provides a hybrid vehicle, which comprises an engine, an ISG motor and a controller according to the third aspect of the present application.

[0023] Additional aspects and advantages of the present application will be given in part in the following description, become apparent from the following description, or be understood through practice of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 is a flow chart of the engine control method of the hybrid vehicle according to one embodiment of the present application;

[0025] Figure 2 is a flow chart of the process of adjusting the engine speed to the idle minimum power generation speed according to one embodiment of the present application;

[0026] Figure 3is a flowchart of an engine control method of a hybrid vehicle according to an embodiment of the present application;

[0027] Figure 4 is a structural block diagram of a controller according to an embodiment of the present application;

[0028] Figure 5 is a schematic diagram of a hybrid vehicle according to an embodiment of the present application. DETAILED DESCRIPTION

[0029] Embodiments of the present application are described in detail below with reference to the accompanying drawings, in which like or similar elements or components are denoted by like reference numbers throughout the several views. The embodiments described below are exemplary, and are intended to explain the present application, and are not to be understood as limiting the present application.

[0030] Embodiments of the present application are described in detail below with reference to the accompanying drawings, in which like or similar elements or components are denoted by like reference numbers throughout the several views. The embodiments described below are exemplary, and are intended to explain the present application, and are not to be understood as limiting the present application. Figures 1-5 Embodiments of the present application are described in detail below with reference to the accompanying drawings, in which like or similar elements or components are denoted by like reference numbers throughout the several views. The embodiments described below are exemplary, and are intended to explain the present application, and are not to be understood as limiting the present application.

[0031] In an embodiment of the present application, the hybrid vehicle can include an engine and an ISG (Integrated Starter and Generate motor) motor.

[0032] Figure 1 is a flowchart of an engine control method of a hybrid vehicle according to an embodiment of the present application. As shown in Figure 1 the engine control method of the hybrid vehicle can include:

[0033] S101, in response to a shutdown demand of the engine, controlling the engine to reduce torque, and using the ISG motor to stabilize the engine speed at an idle minimum power generation speed;

[0034] S102, 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 pull the engine to a stop.

[0035] For example, when the target operating mode of the engine is switched from parallel / series operating mode to shutdown operating mode, or when it is determined that the engine needs to be shut down according to the State of Charge (SOC) of the power battery, the discharge power, the driving demand power, etc.

[0036] The embodiment of the present application adopts a power domain controller to control an engine controller (ECM) and an ISG motor, and completes the stop control of the engine.

[0037] In the embodiment of the present application, the power domain controller can be a power-train control module (PCM), a vehicle control unit (VCU), an electronic control unit (ECU), etc.

[0038] In the embodiment of the present application, when the engine is controlled to stop, in order to accelerate the convergence of the engine speed, the PCM controls the output torque of the ISG motor while controlling the ECM to reduce the torque of the engine and reduce the engine speed. That is, the engine speed is controlled by the ECM and the ISG motor together, so as to quickly adjust the engine speed to the idle speed minimum power generation speed and stabilize at the idle speed minimum power generation speed. When the PCM controls the ECM to reduce the torque of the engine to zero, the engine speed is controlled by the ISG motor alone, and when the time for the engine speed to stabilize at the idle speed minimum power generation speed reaches the first preset time N1, the engine is stopped by controlling the ISG motor, so as to ensure the stability of the system state before stopping.

[0039] In the embodiment of the present application, when the ISG motor is controlled to stop the engine, the target speed of the ISG motor can be converted to 0 rpm (revolutions per minute), so as to reverse the engine speed to 0 rpm by the feedback torque output by the ISG motor.

[0040] In one embodiment of the present application, as shown in Figure 2 controlling the engine to reduce the torque and stabilizing the engine speed at the idle speed minimum power generation speed by using the ISG motor can include:

[0041] S201, determining the idle speed target indicated torque and the idle speed minimum power generation speed;

[0042] S202, controlling the torque of the engine to reduce to the idle speed target indicated torque, and controlling the ISG motor according to the real-time speed of the engine, so as to stabilize the engine speed at the idle speed minimum power generation speed;

[0043] S203, when the time for the engine speed to stabilize at the idle speed minimum power generation speed reaches the second preset time, controlling the torque of the engine to reduce from the idle speed target indicated torque to zero, and controlling the ISG motor to increase the torque, so as to stabilize the engine speed at the idle speed minimum power generation speed when the time reaches the first preset time.

[0044] Specifically, after determining the idle target indicative torque T1 and the idle minimum generating speed, the PCM sends the idle target indicative torque T1 to the ECM. The ECM controls the torque of the engine to decrease to the idle target indicative torque T1 in response to the idle target indicative torque T1 sent by the PCM. The PCM sends the idle minimum generating speed to the ISG motor at the same time when sending the idle target indicative torque T1 to the ECM, so as to control the output load torque of the ISG motor according to the real-time speed of the engine and the idle minimum generating speed while the ECM is controlling the engine torque to decrease. The speed of the engine is adjusted by the ECM and the ISG motor together, so that the speed of the engine is quickly adjusted to the idle minimum generating speed.

[0045] The embodiment of the present application quickly adjusts the speed of the engine to the idle minimum generating speed and stabilizes the speed of the engine at the idle minimum generating speed by the way of feeding forward adjusting the engine torque and feeding back adjusting the ISG motor torque, so as to realize the quick convergence of the speed of the engine.

[0046] When the time for stabilizing the speed of the engine at the idle minimum generating speed reaches the second preset time N2, the PCM decays the target indicative torque T1 to zero at a certain rate, and controls the torque of the engine to decrease from the idle target indicative torque T1 to zero torque by the ECM, while controlling the ISG motor to start the segmented torque increase. The stable control of the speed of the engine by the ECM and the ISG motor together is changed to the stable control of the speed of the engine by the ISG motor alone, so that the speed of the engine is stabilized at the idle minimum generating speed.

[0047] Before controlling the engine to stop, the embodiment of the present application controls the speed of the engine by the ECM and the ISG motor together, and controls the speed of the engine by the ISG motor and the ECM together to transit to the control of the speed of the engine by the ISG motor alone, so as to ensure the stable system state before the engine stops.

[0048] In an embodiment of the present application, the determination of the idle target indicative torque can include:

[0049] The idle target indicative torque is determined according to the speed of the engine before the engine stops in response to the stop demand of the engine and the coolant temperature.

[0050] Specifically, the PCM can determine the idle target indicative torque according to the speed of the engine before the engine stops in response to the stop demand of the engine and the coolant temperature by the look-up table method, and send the idle target indicative torque T1 to the ECM.

[0051] The embodiment of the present application takes the engine system resistance torque looked up from the engine speed and the coolant temperature as the feed-forward link.

[0052] In an embodiment of the present application, the determination of the idle minimum generating speed can include:

[0053] The idle minimum power generation rotation speed is determined according to the smaller one of the rotation speed of the engine before the engine stop demand and the idle stop maximum rotation speed.

[0054] Specifically, the PCM determines the smaller one of the rotation speed of the engine before the engine stop demand and the idle stop maximum rotation speed, and sends the idle minimum power generation rotation speed to the ISG motor.

[0055] In one embodiment of the present application, the ISG motor is controlled according to the real-time rotation speed of the engine to stabilize the rotation speed of the engine at the idle minimum power generation rotation speed, which can include:

[0056] calculating the difference between the real-time rotation speed of the engine and the idle minimum power generation rotation speed;

[0057] controlling the ISG motor according to the difference to stabilize the rotation speed of the engine at the idle minimum power generation rotation speed.

[0058] Specifically, the difference between the real-time rotation speed of the engine and the idle minimum power generation rotation speed is calculated, and the ISG torque is output according to the calculated difference to perform feedback control to stabilize the rotation speed of the engine at the idle minimum power generation rotation speed.

[0059] The embodiment of the present application controls the ISG motor to perform closed-loop coordinated control on the rotation speed of the engine, and adjusts the rotation speed of the engine to the idle minimum power generation rotation speed.

[0060] In one embodiment of the present application, during the process of controlling the ISG motor according to the real-time rotation speed of the engine to stabilize the rotation speed of the engine at the idle minimum power generation rotation speed, the engine control method of the hybrid vehicle can further include:

[0061] if the real-time rotation speed of the engine is less than the minimum preset rotation speed, reducing the output torque of the ISG motor;

[0062] if the real-time rotation speed of the engine is greater than or equal to the minimum preset rotation speed and less than the idle minimum power generation rotation speed, performing the step of controlling the ISG motor to pull the engine to stop.

[0063] Specifically, during the process of controlling the ISG motor according to the real-time rotation speed of the engine to stabilize the rotation speed of the engine at the idle minimum power generation rotation speed, if the rotation speed of the engine is lower than the minimum set rotation speed during the adjustment process, the output torque of the ISG motor is controlled to be reduced to prevent the engine load torque from being too large and causing the engine to stall. If the rotation speed of the engine is still lower than the minimum set rotation speed when the output torque of the ISG motor is reduced to 0, the ISG motor is controlled to pull the engine to stop. If the real-time rotation speed of the engine is greater than or equal to the minimum preset rotation speed and less than the idle minimum power generation rotation speed, the ISG motor is controlled to pull the engine to stop.

[0064] In an embodiment of the present application, the minimum preset rotation speed can be 500-800 rpm.

[0065] In an embodiment of the present application, the engine control method of the hybrid vehicle further comprises:

[0066] The pressure in the engine cylinder is controlled when the torque of the engine is reduced to zero.

[0067] Specifically, the PCM controls the ECM to control the pressure in the engine cylinder when the torque of the engine is reduced to zero, so that the pressure in the engine cylinder is controlled, and knocking noise generated during the shutdown process is avoided.

[0068] In an embodiment of the present application, controlling the pressure in the engine cylinder comprises: controlling the engine to prohibit fuel injection and closing the throttle valve of the engine.

[0069] Specifically, when the torque of the engine is unloaded to zero, the engine is controlled to prohibit fuel injection and the throttle valve of the engine is closed.

[0070] The PCM can control the ECM to perform the throttle valve closing action and send a fuel injection prohibition instruction to the ECM, and the ECM controls the engine to prohibit fuel injection in response to the fuel injection prohibition instruction. It should be noted that the engine prohibits fuel injection but does not stop ignition.

[0071] The embodiment of the present application controls the throttle valve of the engine to be closed before controlling the engine to be shut down, so that the in-cylinder pressure is controlled, the excessive torque vibration and reverse rotation of the engine during shutdown are inhibited, and the problem of gear pair knocking caused by engine reverse rotation is avoided.

[0072] In an embodiment of the present application, the engine control method of the hybrid vehicle further comprises: prohibiting ignition of the engine.

[0073] Specifically, the PCM sends a shutdown command, and the ECM controls the ignition to be enabled to be prohibited in response to the shutdown command, so as to prohibit the ignition of the engine.

[0074] In an embodiment of the present application, controlling the ISG motor to increase torque can comprise:

[0075] According to the idle minimum power generation rotation speed, the slope of the load or unload of the ISG motor output torque in the target torque range is reduced.

[0076] Specifically, while the torque of the engine is reduced from the idle target indication torque T1 to zero torque, according to the idle minimum power generation rotation speed, the slope of the load or unload of the ISG motor output torque in the target torque range is reduced.

[0077] In an embodiment of the present application, the engine control method of the hybrid vehicle further comprises:

[0078] In the process of controlling the ISG motor to increase torque to stabilize the engine speed at the idle minimum power generation speed, when the engine speed fluctuates, the output torque of the ISG motor is unidirectionally limited.

[0079] Specifically, in the process of controlling the ISG motor to increase torque to stabilize the engine speed at the idle minimum power generation speed, when the engine speed fluctuates, the output torque of the ISG motor is unidirectionally limited. That is, according to the positive or negative of the output torque of the ISG motor at the last moment, the positive or negative of the output torque of the ISG motor at the current moment is determined, to avoid the gear knocking caused by the frequent change of the ISG torque over 0.

[0080] As a specific embodiment, as shown in Figure 3 The PCM sends the idle target indication torque T1 to the ECM and starts timing Time1. The PCM sends the idle minimum power generation speed to the ISG motor according to the minimum of the engine speed before the engine stops in response to the engine stop demand and the idle stop maximum speed. The PCM compares the real-time engine speed with the idle minimum power generation speed, calculates the ISG adjustment speed torque according to the difference obtained by comparison, and executes the ISG. If the engine speed is less than the minimum set speed during the adjustment, the ISG adjustment torque is reduced to prevent the engine load torque from being too large, which causes the engine to stall. If the engine speed is greater than or equal to the minimum set speed and less than the idle minimum power generation speed, the ISG motor is controlled to pull the engine to stop. When the timing Time1 is reached (it is to be noted that the time for the engine speed to stabilize at the idle minimum power generation speed reaches the second preset time N2, i.e., Time1>N2), the PCM decays the target indication torque T1 at a certain rate and starts timing Time2. The ISG torque is further adjusted according to the idle minimum power generation speed when the target indication torque T1 starts to decay, and the slope of the ISG torque loading or unloading is reduced in the torque [-T_isg, T_isg] interval. When the torque of the engine is reduced to zero, the PCM controls the ECM to perform the throttle closing action and sends the prohibition of fuel injection instruction to the ECM, and the ECM controls the engine to prohibit fuel injection in response to the prohibition of fuel injection instruction. When the timing Time2 is reached (it is to be noted that the time for the engine speed to stabilize at the idle minimum power generation speed reaches the first preset time N1, i.e., Time2>N1), the ISG motor is controlled to pull the engine to stop.

[0081] The engine control method of the hybrid vehicle of the embodiment of the present application controls the ISG and the engine in coordination, so that the engine speed and the rotational inertia before shutdown have high consistency; the control of the throttle valve before shutdown can inhibit excessive torsional vibration and reverse rotation of the engine before shutdown, and avoid problems such as gear pair knocking caused by engine reverse rotation.

[0082] The engine control method of the hybrid vehicle of the embodiment of the present application uses the regulation mode of feedforward plus feedback to quickly stabilize the engine speed, and changes the control of the engine speed before shutdown from being controlled by the ISG and the ECM together to being controlled by the ISG alone, thereby ensuring stable system state before shutdown, and making the cylinder pressure controllable by closing the throttle valve and prohibiting fuel injection before shutdown, and avoiding knocking noise during shutdown.

[0083] It should be noted that the ISG motor is usually used for starting the hybrid vehicle, and for the hybrid vehicle with double-motor series-parallel connection or extended-range structure, the engine and the generator are connected through a gear pair and a torque damper, and the inertia of the generator is much larger than that of the conventional vehicle with a starter, so the stability of the engine speed and the load torque and the cylinder pressure at the initial state before shutdown have obvious influence on the NVH (Noise, Vibration, Harshness) quality. The control method of the embodiment of the present application can also improve the shutdown NVH quality of the hybrid vehicle.

[0084] The present application provides a computer readable storage medium.

[0085] In this embodiment, the computer readable storage medium stores a computer program, and the computer program is executed by the processor to implement the engine control method of the hybrid vehicle as described above.

[0086] The present application provides a controller.

[0087] In this embodiment, the controller can include a memory and a processor, and the memory stores a computer program, and the computer program is executed by the processor to implement the engine control method of the hybrid vehicle as described above.

[0088] Figure 4 The present application provides a controller.

[0089] As shown in Figure 4 The controller 500 includes a processor 501 and a memory 503. The processor 501 and the memory 503 are connected, for example, through a bus 502. Optionally, the controller 500 can also include a transceiver 504. It should be noted that in actual application, the transceiver 504 is not limited to one, and the structure of the controller 500 does not constitute a limitation on the embodiments of the present application.

[0090] The processor 501 can 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 device, transistor logic device, hardware component, or any combination thereof. It can implement or execute various exemplary logical blocks, modules and circuits described in conjunction with the present disclosure. The processor 501 can 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.

[0091] The bus 502 can include a path for transmitting information between the above-mentioned components. The bus 502 can be a PCI (Peripheral Component Interconnect) bus or an EISA (Extended Industry Standard Architecture) bus, or the like. The bus 502 can be divided into an address bus, a data bus, a control bus, and the like. For convenience of representation, Figure 4 In the figure, only one thick line is used to represent, but it does not mean that there is only one bus or only one type of bus.

[0092] The memory 503 is used to store a computer program corresponding to the engine control method of the hybrid vehicle of the above-mentioned embodiments of the present application, which is controlled and executed by the processor 501. The processor 501 is used to execute the computer program stored in the memory 503 to realize the content shown in the foregoing method embodiments.

[0093] The controller 500 includes, but is not limited to, a mobile terminal such as a mobile phone, a notebook computer, a digital broadcast receiver, a PDA (Personal Digital Assistant), a PAD (Tablet Personal Computer), a PMP (Portable Multimedia Player), a vehicle terminal (such as a vehicle navigation terminal), and the like, and a fixed terminal such as a digital TV, a desktop computer, and the like. Figure 4 The controller 500 shown is only an example, and should not bring any limitation to the functions and use range of the embodiments of the present application.

[0094] The computer readable storage medium and the controller of the embodiments of the present application utilize the above-mentioned engine control method of the hybrid vehicle, ensure that the engine speed control response before shutdown is fast, the system state is stable, the engine speed change at shutdown is controllable, and knocking abnormal sound during shutdown process is avoided.

[0095] The present application provides a hybrid vehicle.

[0096] Figure 5 is a schematic diagram of a hybrid vehicle according to an embodiment of the present application. As shown, the hybrid vehicle 100 can include an engine, an ISG motor and a controller as described above. Figure 5

[0097] It is noted that the controller described above is a power domain controller. Exemplarily, a PCM, a VCU, an ECU, etc. can be used.

[0098] The hybrid vehicle according to the embodiment of the present application ensures the fast response of the engine speed control before shutdown, the stability of the system state, and the controllability of the engine speed change at shutdown, thereby avoiding the knocking abnormal sound during the shutdown process.

[0099] It is noted that the logic and / or steps represented in the flowcharts and / or otherwise described herein, for example, can be considered as a list of executable instructions for implementing logic functions, and can be specifically embodied in any computer-readable medium for use by or in connection with an instruction execution system, apparatus or device, such as a computer-based system, a processor-based system, or other system that can fetch the instructions from the instruction execution system, apparatus or device and execute the instructions, or in conjunction with which the instructions can be executed. For the purpose of this specification, a "computer-readable medium" can be any apparatus that can contain, store, communicate, propagate or transport the program for use by or in connection with the instruction execution system, apparatus or device, or in conjunction with which the instructions can be executed. More specific examples (a non-exhaustive list) of the computer-readable medium include the following: an electrical connection having one or more wires (electronic devices), a portable computer diskette (magnetic devices), a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber device, and a portable compact disc read-only memory (CDROM). In addition, the computer-readable medium can even be paper or other suitable medium on which the program can be printed, as the program can be electronically obtained, for example, by optical scanning of the paper or other medium, followed by electronic conversion of the scanned program, and then storage in a computer memory if necessary. The program can be processed by one or more processors, such as one or more digital signal processors (DSPs), general purpose microprocessors, application specific integrated circuits (ASICs), field programmable gate arrays (FPGAs), or other equivalent integrated circuits or logic elements.

[0100] ​It should be understood that aspects of the application can be implemented in hardware, software, firmware or combinations thereof. In the embodiments described above, various steps or methods can be implemented, for example, through software or firmware in storage media which are executable by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, any of the following technologies, known in the art, or their combinations, can be employed: discrete logic circuitry having logic gates for implementing logic functions upon an application of data signals, application-specific integrated circuits having appropriate combinational logic gates, programmable gate arrays (PGA), field-programmable gate arrays (FPGA), and so on.

[0101] In the description of the present application, the description of the terms "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are contained in at least one embodiment or example of the present application. In the present description, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0102] In the description of the present application, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0103] In addition, the terms "first", "second" are only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined with "first", "second" can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "a plurality of" is at least two, for example, two, three, etc., unless otherwise specifically limited.

[0104] In the present application, unless specifically defined otherwise, the terms "mounting", "connected", "connecting", "fixed", and the like should be construed broadly, for example, can be fixed connection, can also be detachable connection, or integral; can be mechanical connection, can also be electrical connection; can be directly connected, can also be indirectly connected through an intermediate medium, can be the internal communication of two elements or the interaction relationship of two elements, unless specifically defined otherwise. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0105] In the present application, unless specifically defined otherwise, the first feature is "on" or "under" the second feature can be that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature "above", "over" and "on" the second feature can be that the first feature is directly above or obliquely above the second feature, or only indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature "below", "under" and "under" the second feature can be that the first feature is directly below or obliquely below the second feature, or only indicates that the horizontal height of the first feature is less than that of the second feature.

[0106] 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 construed as limiting the present application, and those skilled in the art can make changes, modifications, replacements and variations to the above embodiments within the scope of the present application.

Claims

1. An engine control method for a hybrid vehicle, characterized in that, The hybrid vehicle includes an engine and an ISG motor, and the method includes: In response to the engine's shutdown requirement, the engine is controlled to reduce torque, and the ISG motor is used to stabilize the engine speed at the minimum idle speed for generating electricity. When the engine torque drops to zero and the engine speed stabilizes at the minimum idle speed for a first preset time, the ISG motor is controlled to stop the engine.

2. The engine control method for a hybrid vehicle according to claim 1, characterized in that, The control of the engine to reduce torque and the use of the ISG motor to stabilize the engine speed at the minimum idle speed for power generation include: Determine the target idle torque and the minimum idle generator speed; The torque of the engine is controlled to be reduced to the idle target indicated torque, and the ISG motor is controlled according to the real-time speed of the engine to stabilize the speed of the engine at the minimum idle generating speed. When the engine speed stabilizes at the minimum idle speed for a second preset time, the engine torque is controlled to drop from the target idle torque to zero, and the ISG motor is controlled to increase torque so that the engine speed is stabilized at the minimum idle speed for a first preset time.

3. The engine control method for a hybrid vehicle according to claim 1, characterized in that, The method further includes: When the torque of the engine drops to zero, the pressure inside the engine cylinder is controlled.

4. The engine control method for a hybrid vehicle according to claim 2, characterized in that, Determining the target idle torque includes: The idle target indicated torque is determined based on the engine speed and coolant temperature prior to the engine shutdown requirement.

5. The engine control method for a hybrid vehicle according to claim 2, characterized in that, Determining the minimum idle speed for power generation includes: The minimum idle speed for generating electricity is determined based on the smaller of the engine speed before responding to the engine shutdown request and the maximum idle shutdown speed.

6. The engine control method for a hybrid vehicle according to claim 3, characterized in that, The control of the pressure within the engine cylinder includes: Control the engine to disable fuel injection and close the engine throttle valve.

7. The engine control method for a hybrid vehicle according to claim 6, characterized in that, The method further includes: Ignition of the engine is prohibited.

8. The engine control method for a hybrid vehicle according to claim 2, characterized in that, The step of controlling the ISG motor according to the real-time speed of the engine to stabilize the engine speed at the minimum idle speed includes: Calculate the difference between the real-time speed of the engine and the minimum idle speed for generating electricity; The ISG motor is controlled based on the difference to stabilize the engine speed at the minimum idle speed for generating electricity.

9. The engine control method for a hybrid vehicle according to claim 2, characterized in that, The method further includes controlling the ISG motor according to the real-time speed of the engine to stabilize the engine speed at the minimum idle speed for power generation. If the real-time speed of the engine is less than the minimum preset speed, the output torque of the ISG motor is reduced. If the real-time speed of the engine is greater than or equal to the minimum preset speed and less than the minimum idle speed for generating electricity, then the step of controlling the ISG motor to stop the engine is executed.

10. The engine control method for a hybrid vehicle according to claim 2, characterized in that, The control of the ISG motor to increase torque includes: Based on the minimum idle speed for generating electricity, the slope of loading or unloading the output torque of the ISG motor is reduced within the target torque range.

11. The engine control method for a hybrid vehicle according to claim 8, characterized in that, The method further includes: In the process of controlling the ISG motor to increase torque and stabilize the engine speed at the minimum idle speed, when the engine speed fluctuates, the output torque of the ISG motor is unidirectionally limited.

12. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the engine control method for a hybrid vehicle as described in any one of claims 1-11.

13. A controller, comprising a memory and a processor, wherein the memory stores a computer program, characterized in that, When the computer program is executed by the processor, it implements the engine control method for a hybrid vehicle as described in any one of claims 1-11.

14. A hybrid vehicle, characterized in that, include: The engine, the ISG motor, and the controller as described in claim 13.

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