Engine control method and device and storage medium

Abstract

The invention discloses an engine control method and device and a storage medium, and belongs to the technical field of vehicle control. The method comprises the steps that the rotating speed, the load, the variable valve timing angle, the water temperature and the intake manifold temperature before an engine stops are obtained; calculating the oil film residual volume on the inner wall surface of the combustion chamber when the engine is shut down; calculating a preset throttle opening degree when the engine is stopped based on the oil film residual amount and the rotating speed of the engine; the engine is controlled to start to execute shutdown ventilation operation at the preset throttle opening degree; the air-fuel ratio of gas exhausted by the engine is continuously obtained in the shutdown ventilation operation; whether the air inflow of the engine reaches the air inflow needed in the engine shutdown process or not is judged based on the air-fuel ratio; and in response to the fact that the air inflow of the engine reaches the air inflow needed in the engine shutdown process, the engine is controlled to be shut down through the motor. Fuel oil in the combustion chamber is discharged through exhaust of the engine, and the compression ignition phenomenon during next-time starting is avoided.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of vehicle control technology, and in particular to a method, device and storage medium for controlling an engine. Background Art

[0002] During engine operation, a certain amount of fuel will be stored in the narrow gaps and pits in the combustion chamber, such as the gaps around the valve and between the cylinder head. When the engine is shut down after being fully warmed up, the cooling water and oil cooling stop, and the temperature in the combustion chamber further increases, causing the fuel in the gaps and pits to volatilize and remain in the combustion chamber. When the air-fuel ratio in the combustion chamber reaches the compression ignition condition, if the engine is started again, when the engine speed reaches 200-500rpm, the engine will undergo compression ignition, resulting in reduced fuel efficiency, increased harmful substances emitted by the vehicle, and even engine damage. Therefore, how to avoid the occurrence of compression ignition is a problem that needs to be solved. Summary of the invention

[0003] The present application provides an engine control method, device and storage medium, which can be used to prevent compression ignition from occurring in the engine. The technical solution is as follows:

[0004] In one aspect, an embodiment of the present application provides a method for controlling an engine, the method comprising:

[0005] Obtain the engine speed, load, variable valve timing angle, water temperature and intake manifold temperature before shutdown;

[0006] Calculating the amount of oil film residue on the inner wall surface of the combustion chamber when the engine is stopped based on the speed, the load, the variable valve timing angle, the water temperature, and the intake manifold temperature;

[0007] calculating a preset throttle opening when the engine is stopped based on the residual oil film amount and the engine speed, wherein the preset throttle opening is considered to satisfy the intake air amount required during the engine stop process;

[0008] Controlling the engine to start a stop ventilation operation at the preset throttle opening;

[0009] Continuously obtaining the air-fuel ratio of the gas exhausted by the engine during the shutdown ventilation operation;

[0010] determining, based on the air-fuel ratio, whether the intake air amount of the engine reaches the intake air amount required during the engine shutdown process;

[0011] In response to the intake air amount of the engine reaching the intake air amount required during the engine stop process, the engine is stopped by controlling the motor.

[0012] In another aspect, a control device for an engine is provided, the device comprising:

[0013] A first acquisition module is used to acquire the speed, load, variable valve timing angle, water temperature and intake manifold temperature of the engine before shutdown;

[0014] A first calculation module, configured to calculate the amount of residual oil film on the inner wall surface of the combustion chamber when the engine is stopped based on the rotation speed, the load, the variable valve timing angle, the water temperature, and the intake manifold temperature;

[0015] a second calculation module, configured to calculate a preset throttle opening when the engine is stopped based on the residual oil film amount and the engine speed, wherein the preset throttle opening is considered to satisfy the intake air volume required during the engine stop process;

[0016] A first control module, used for controlling the engine to start the shutdown ventilation operation at the preset throttle opening;

[0017] A second acquisition module, used for continuously acquiring the air-fuel ratio of the gas exhausted by the engine during the shutdown ventilation operation;

[0018] A judgment module, used for judging whether the intake air amount of the engine reaches the intake air amount required during the engine shutdown process based on the air-fuel ratio;

[0019] The second control module is used for controlling the engine to stop through a motor in response to the intake air volume of the engine reaching the intake air volume required during the engine stop process.

[0020] On the other hand, a non-temporary computer-readable storage medium is also provided, characterized in that a computer program is stored in the computer-readable storage medium, and the computer program is loaded and executed by a processor to implement any of the above-mentioned engine control methods.

[0021] On the other hand, a computer program product is also provided, the computer program product comprising computer instructions, and the computer instructions, when executed by a processor, implement the steps of any of the above-mentioned engine control methods.

[0022] The technical solution provided by this application brings at least the following beneficial effects:

[0023] The present application calculates the amount of oil film residue on the wall surface of the combustion chamber when the engine is stopped by obtaining the speed, load, variable valve timing angle, water temperature and intake manifold temperature before the engine is stopped; then presets a preset throttle opening when the engine is stopped according to the amount of oil film residue and the speed of the engine; controls the engine to start the shutdown ventilation operation with the preset throttle opening, and continuously obtains the air-fuel ratio of the gas exhausted by the engine during the shutdown ventilation operation, so as to judge whether the intake volume of the engine reaches the intake volume required during the engine shutdown process; in response to the intake volume of the engine reaching the intake volume required during the engine shutdown process, controls the engine to stop through a motor, and discharges the fuel in the combustion chamber through the engine exhaust, so as to avoid compression ignition at the next start, thereby ensuring the safety of the engine and the vehicle while avoiding a decrease in fuel efficiency and an increase in harmful substances emitted by the vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0025] Figure 1 It is a schematic diagram of an implementation environment provided by an embodiment of the present application;

[0026] Figure 2 is a flow chart of an engine control method provided by an embodiment of the present application;

[0027] Figure 3 It is a control logic diagram of an engine provided by an embodiment of the present application;

[0028] Figure 4 It is a structural schematic diagram of an engine control device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0029] In order to make the objectives, technical solutions and advantages of the present application clearer, the implementation methods of the present application will be further described in detail below with reference to the accompanying drawings.

[0030] The present application provides a method for controlling an engine. Figure 1, which shows a schematic diagram of the implementation environment of the method provided in the embodiment of the present application. The implementation environment may include: ECU (Electronic Control Unit) 11, speed sensor 12, intake manifold absolute pressure sensor 13, position sensor 14, first temperature sensor 15, second temperature sensor 16, throttle position sensor 17, front oxygen sensor 18, fuel injection system 19, ETC (Electronic Throttle Control) system 20, throttle actuator 21 and motor 22.

[0031] For example, the speed sensor 12 is used to obtain the speed of the engine before stopping and send it to the ECU 11, wherein the speed sensor 12 can be installed on the crankshaft or the flywheel. The intake manifold absolute pressure sensor 13 is used to measure the intake pressure of the engine and send it to the ECU 11, and the ECU 11 calculates the load of the engine according to the intake pressure, wherein the intake manifold absolute pressure sensor 13 can be installed upstream of the intake manifold and close to the throttle position.

[0032] In a possible implementation, the position sensor 14 is used to read the variable valve timing angle before the engine is stopped and send it to the ECU 11, wherein the position sensor 14 can be installed on the camshaft or the valve. The first temperature sensor 15 is used to detect the water temperature before the engine is stopped and send it to the ECU 11, wherein the first temperature sensor 15 can be installed near the thermostat or the radiator. The second temperature sensor 16 is used to detect the intake manifold temperature before the engine is stopped and send it to the ECU 11, wherein the second temperature sensor 16 can be installed on the intake manifold.

[0033] Optionally, the fuel injection system 19 is used to inject fuel into the engine, and the fuel interruption of the engine can be achieved by controlling the fuel injection system 19. The ETC system 20 is used to send a control signal corresponding to a preset throttle opening to the throttle actuator 21, and the throttle actuator 21 is used to adjust the throttle to the preset throttle opening. The throttle position sensor 17 is used to monitor the actual opening of the current throttle in real time and send it to the ECU 11. The motor 22 is used to control the engine to rotate or stop.

[0034] In a possible implementation, the front oxygen sensor 18 is used to continuously obtain the oxygen concentration in the gas exhausted by the engine during the shutdown ventilation operation and send it to the ECU 11, wherein the front oxygen sensor 18 is usually installed in the exhaust system. The oxygen concentration is used to calculate the air-fuel ratio of the gas exhausted by the engine, and based on the air-fuel ratio, it is determined whether the intake amount of the engine reaches the intake amount required during the engine shutdown process.

[0035] Among them, ECU 11, speed sensor 12, intake manifold absolute pressure sensor 13, position sensor 14, first temperature sensor 15, second temperature sensor 16, throttle position sensor 17, front oxygen sensor 18, fuel injection system 19, ETC system 20, throttle actuator 21 and motor 22 establish communication connection through wired or wireless network.

[0036] Based on the above Figure 1 In the implementation environment shown, the present application embodiment provides a method for controlling an engine as shown in FIG. Figure 2 As shown, taking the method applied to ECU as an example, the method includes steps 201 to 207.

[0037] In step 201 , the ECU obtains the speed, load, variable valve timing angle, water temperature and intake manifold temperature before the engine is shut down.

[0038] Exemplarily, the following is an example of a method for obtaining various parameters of an engine.

[0039] (1) Obtain the engine speed before shutdown

[0040] In a possible implementation, the ECU can obtain the engine speed before shutdown through a speed sensor. The speed sensor is installed on the crankshaft or flywheel, detects the engine speed, and converts the engine speed into an electrical signal and sends it to the ECU. The ECU obtains the engine speed before shutdown by analyzing the electrical signal corresponding to the speed.

[0041] (2) Obtain the load before the engine stops

[0042] Optionally, the ECU can measure the intake pressure of the engine through an intake manifold absolute pressure sensor, and then calculate the engine load based on the intake pressure. Among them, the intake manifold absolute pressure sensor can detect the intake pressure of the engine.

[0043] (3) Obtaining the variable valve timing angle before the engine stops

[0044] For example, the ECU can read the variable valve timing angle before the engine stops through a position sensor installed on the camshaft or the valve, wherein the position sensor is installed on the camshaft or the valve to measure the position of the VVT ​​actuator.

[0045] (4) Obtain the water temperature before the engine stops

[0046] In a possible implementation, the ECU can detect the water temperature before the engine is shut down through a first temperature sensor, wherein the first temperature sensor is installed near a thermostat or a radiator and can directly measure the temperature of the engine coolant.

[0047] (5) Obtain the intake manifold temperature before engine shutdown

[0048] Optionally, the ECU can detect the intake manifold temperature before the engine is shut down through a second temperature sensor, wherein the second temperature sensor is installed on the intake manifold to detect the intake manifold temperature.

[0049] In step 202, the ECU calculates the amount of oil film residue on the inner wall of the combustion chamber when the engine is stopped based on the speed, load, variable valve timing angle, water temperature and intake manifold temperature.

[0050] In one possible implementation, after obtaining the speed, load, variable valve timing angle, water temperature and intake manifold temperature before the engine is shut down, the ECU calculates the residual amount of oil film on the inner wall of the combustion chamber when the engine is shut down based on the speed, load, variable valve timing angle, water temperature and intake manifold temperature, including: the ECU inputs the speed, load, variable valve timing angle, water temperature and intake manifold temperature into a preset model for calculating the residual amount of oil film on the inner wall of the combustion chamber to obtain the residual amount of oil film on the inner wall of the combustion chamber.

[0051] Exemplarily, the model for calculating the residual amount of oil film on the inner wall of the combustion chamber can be obtained through data training. For example, for a certain model of vehicle, an initial calculation model can be established based on experience in combination with the performance of the vehicle, and then the initial model is trained through multiple sets of speed, load, variable valve timing angle, water temperature and intake manifold temperature of the vehicle of the model and the corresponding residual amount of oil film on the inner wall of the combustion chamber, so as to obtain a model for calculating the residual amount of oil film on the inner wall of the combustion chamber suitable for the vehicle of the model.

[0052] In step 203, the ECU calculates a preset throttle opening when the engine is stopped based on the residual oil film and the engine speed. The preset throttle opening is considered to meet the required intake air volume during the engine stop process.

[0053] Optionally, after completing the calculation of the residual oil film on the inner wall of the combustion chamber, the ECU calculates the preset throttle opening when the engine is stopped based on the residual oil film and the engine speed, wherein the preset throttle opening is considered to meet the required intake volume during the engine shutdown process.

[0054] Exemplarily, the ECU calculates a preset throttle opening when the engine is stopped based on the amount of oil film residue and the engine speed, including: the ECU calculates the intake amount required during the engine stop process based on the amount of oil film residue and the engine speed; and calculates the preset throttle opening when the engine is stopped based on the intake amount.

[0055] In a possible implementation, the ECU may determine the required intake air volume during the engine stop process corresponding to the current oil film residual amount and the engine speed based on the oil film residual amount and the engine speed, according to the corresponding relationship between the oil film residual amount and the engine speed and the intake air volume required during the engine stop process. Alternatively, the corresponding relationship between the oil film residual amount and the engine speed and the intake air volume required during the engine stop process may be determined based on experiments.

[0056] In a possible implementation, after determining the intake amount required during the current engine shutdown, the ECU calculates the preset throttle opening when the engine is shut down based on the intake amount, including: based on the intake amount required during the current engine shutdown, determining the preset throttle opening when the engine is shut down according to the correspondence between the intake amount required during the engine shutdown and the throttle opening. Exemplarily, the correspondence between the intake amount required during the engine shutdown and the throttle opening can be determined based on experiments.

[0057] In step 204, the ECU controls the engine to start the stop ventilation operation with a preset throttle opening.

[0058] Optionally, after calculating the preset throttle opening, the ECU controls the engine to start a shutdown ventilation operation with the preset throttle opening, including: the ECU controls the engine's fuel cutoff, adjusts the throttle to the preset throttle opening and controls the engine to rotate at a preset speed through the motor.

[0059] In a possible implementation, the ECU stops injecting fuel to the engine through the fuel injection system to control the fuel interruption of the engine. Then, the actual opening of the current throttle is obtained in real time through the throttle position sensor, and a control signal corresponding to the preset throttle opening is sent to the throttle actuator through the ETC system, and the throttle actuator adjusts the throttle to the preset throttle opening. For example, the preset speed can be set based on experience.

[0060] In step 205, the ECU continuously obtains the air-fuel ratio of the gas exhausted by the engine during the stop ventilation operation.

[0061] Optionally, after starting the shutdown ventilation operation, the ECU continuously obtains the air-fuel ratio of the gas exhausted by the engine during the shutdown ventilation operation, including: continuously obtaining the oxygen concentration in the gas exhausted by the engine during the shutdown ventilation operation; and calculating the air-fuel ratio of the gas exhausted by the engine based on the oxygen concentration.

[0062] For example, the ECU can continuously obtain the oxygen concentration in the gas exhausted by the engine during the shutdown ventilation operation through the front oxygen sensor, wherein the front oxygen sensor is usually installed in the exhaust system, can monitor the oxygen concentration in the gas exhausted by the engine, and output a voltage signal corresponding to the oxygen concentration. Then, the oxygen concentration in the gas exhausted by the engine is determined based on the voltage signal obtained from the front oxygen sensor, and based on the oxygen concentration, the air-fuel ratio of the gas exhausted by the engine is calculated according to the corresponding relationship between the oxygen concentration and the air-fuel ratio. In a possible implementation, the corresponding relationship between the oxygen concentration and the air-fuel ratio and the voltage values ​​corresponding to different oxygen concentrations can be determined based on experiments.

[0063] In step 206 , the ECU determines whether the intake air amount of the engine reaches the intake air amount required during the engine shutdown process based on the air-fuel ratio.

[0064] Optionally, after obtaining the air-fuel ratio of the gas exhausted by the engine, the ECU determines whether the engine's intake volume reaches the intake volume required during the engine shutdown process based on the air-fuel ratio, including: in response to the air-fuel ratio being lower than an air-fuel ratio threshold, the ECU determines that the engine has not reached the intake volume required during the engine shutdown process, and the air-fuel ratio threshold is the air-fuel ratio when the engine is in a stable operating state; in response to the air-fuel ratio curve being higher than the air-fuel ratio threshold, the ECU determines that the engine has reached the intake volume required during the engine shutdown process.

[0065] Exemplarily, during the execution of the shutdown ventilation operation, after obtaining the air-fuel ratio of the gas exhausted by the engine, the ECU compares the air-fuel ratio of the gas exhausted by the engine with the air-fuel ratio threshold. If the air-fuel ratio is lower than the air-fuel ratio threshold, the ECU determines that the engine has not reached the intake volume required during the engine shutdown process; if the air-fuel ratio curve is higher than the air-fuel ratio threshold, the ECU determines that the engine has reached the intake volume required during the engine shutdown process. In a possible implementation, the air-fuel ratio threshold is the air-fuel ratio when the engine is in a stable working state, which can be predetermined based on experiments.

[0066] In step 207 , in response to the intake air amount of the engine reaching the intake air amount required during the engine shutdown process, the ECU controls the engine to shut down through the motor.

[0067] In a possible implementation, after determining that the engine reaches the intake volume required during the engine shutdown process, the ECU controls the engine to shut down through the motor, including: the ECU starts to pull down the engine speed through the motor until the engine speed is 0.

[0068] In summary, a control logic diagram of an engine provided in an embodiment of the present application is used as an example for illustration. The execution subject may be an ECU. Step 301, the engine starts the shutdown ventilation operation. Step 302, the oil film residual amount calculation module on the inner wall of the combustion chamber calculates the oil film residual amount on the inner wall of the engine combustion chamber. Step 303, the intake air amount calculation module calculates the intake air amount required during the engine shutdown process. Step 304, the throttle opening calculation module calculates the preset throttle opening when the engine is shut down based on the intake air amount. Step 305, the air-fuel ratio calculation module determines whether the intake air amount of the engine reaches the intake air amount required during the engine shutdown process. If the intake air amount of the engine reaches the intake air amount required during the engine shutdown process, enter step 306; if the intake air amount of the engine does not reach the intake air amount required during the engine shutdown process, enter step 302. Step 306, control the engine shutdown through the motor. Step 307, the engine completes shutdown.

[0069] The embodiment of the present application calculates the amount of oil film residue on the wall surface of the combustion chamber when the engine is stopped by obtaining the speed, load, variable valve timing angle, water temperature and intake manifold temperature before the engine is stopped; then presets a preset throttle opening when the engine is stopped according to the amount of oil film residue and the speed of the engine; controls the engine to start the shutdown ventilation operation with the preset throttle opening, and continuously obtains the air-fuel ratio of the gas exhausted by the engine during the shutdown ventilation operation, so as to judge whether the intake volume of the engine reaches the intake volume required during the engine shutdown process; in response to the intake volume of the engine reaching the intake volume required during the engine shutdown process, controls the engine to stop through a motor, and discharges the fuel in the combustion chamber through the engine exhaust, so as to avoid compression ignition at the next start, thereby ensuring the safety of the engine and the vehicle while avoiding a decrease in fuel efficiency and an increase in harmful substances emitted by the vehicle.

[0070] See also Figure 4 , an embodiment of the present application provides a control device for an engine, the device comprising:

[0071] The first acquisition module 401 is used to acquire the speed, load, variable valve timing angle, water temperature and intake manifold temperature of the engine before shutdown;

[0072] The first calculation module 402 is used to calculate the oil film residual amount on the inner wall surface of the combustion chamber when the engine is stopped based on the speed, load, variable valve timing angle, water temperature and intake manifold temperature;

[0073] A second calculation module 403 is used to calculate a preset throttle opening when the engine is stopped based on the residual oil film and the engine speed, and the preset throttle opening is considered to meet the intake volume required during the engine stop process;

[0074] The first control module 404 is used to control the engine to start the shutdown ventilation operation with a preset throttle opening;

[0075] The second acquisition module 405 is used to continuously acquire the air-fuel ratio of the gas exhausted by the engine during the shutdown ventilation operation;

[0076] A judgment module 406, for judging whether the intake air volume of the engine reaches the intake air volume required during the engine shutdown process based on the air-fuel ratio;

[0077] The second control module 407 is used to control the engine to stop through the motor in response to the intake air volume of the engine reaching the intake air volume required during the engine stop process.

[0078] In a possible implementation, the second calculation module 403 is used to calculate the intake air volume required during the engine shutdown process based on the oil film residual amount and the engine speed; and calculate the preset throttle opening when the engine is shut down based on the intake air volume.

[0079] In a possible implementation, the first control module 404 is used to control the fuel cutoff of the engine, adjust the throttle to a preset throttle opening and control the engine to rotate at a preset speed through a motor.

[0080] In a possible implementation, the second acquisition module 405 is used to continuously acquire the oxygen concentration in the gas exhausted by the engine during the shutdown ventilation operation; and calculate the air-fuel ratio of the gas exhausted by the engine based on the oxygen concentration.

[0081] In one possible implementation, the judgment module 406 is used to determine that the engine has not reached the intake volume required during the engine shutdown process in response to the air-fuel ratio being lower than the air-fuel ratio threshold, and the air-fuel ratio threshold is the air-fuel ratio when the engine is in a stable operating state; in response to the air-fuel ratio curve being higher than the air-fuel ratio threshold, determine that the engine has reached the intake volume required during the engine shutdown process.

[0082] In one possible implementation, the first calculation module 402 is used to input the speed, load, variable valve timing angle, water temperature and intake manifold temperature into a preset model for calculating the residual oil film on the inner wall of the combustion chamber to obtain the residual oil film on the inner wall of the combustion chamber.

[0083] The device calculates the amount of oil film residue on the combustion chamber wall surface when the engine is stopped by obtaining the engine speed, load, variable valve timing angle, water temperature and intake manifold temperature before the engine is stopped; then presets a preset throttle opening when the engine is stopped according to the amount of oil film residue and the engine speed; controls the engine to start the shutdown ventilation operation with the preset throttle opening, and continuously obtains the air-fuel ratio of the gas exhausted by the engine during the shutdown ventilation operation, so as to judge whether the engine's intake volume reaches the intake volume required during the engine shutdown process; in response to the engine's intake volume reaching the intake volume required during the engine shutdown process, controls the engine to stop through a motor, and discharges the fuel in the combustion chamber through the engine exhaust, so as to avoid compression ignition at the next start, thereby ensuring the safety of the engine and the vehicle while avoiding a decrease in fuel efficiency and an increase in harmful substances emitted by the vehicle.

[0084] It should be noted that the device provided in the above embodiment only uses the division of the above functional modules as an example to implement its functions. In actual applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the device is divided into different functional modules to complete all or part of the functions described above. In addition, the device and method embodiments provided in the above embodiment belong to the same concept, and their specific implementation process is detailed in the method embodiment, which will not be repeated here.

[0085] In an exemplary embodiment, a computer-readable storage medium is also provided, in which at least one computer program is stored. The at least one computer program is loaded and executed by a processor of a computer device so that the computer implements any of the above-mentioned engine control methods.

[0086] In one possible implementation, the computer-readable storage medium may be a read-only memory (ROM), a random access memory (RAM), a compact disc (CD-ROM), a magnetic tape, a floppy disk, an optical data storage device, etc.

[0087] In an exemplary embodiment, a computer program product or a computer program is also provided, the computer program product or the computer program comprising computer instructions, the computer instructions being stored in a computer-readable storage medium. A processor of a computer device reads the computer instructions from the computer-readable storage medium, and the processor executes the computer instructions, so that the computer device performs any of the above-mentioned engine control methods.

[0088] It should be noted that the information (including but not limited to user device information, user personal information, etc.), data (including but not limited to data for analysis, stored data, displayed data, etc.) and signals involved in this application are all authorized by the user or fully authorized by all parties, and the collection, use and processing of relevant data must comply with the relevant laws, regulations and standards of relevant countries and regions. For example, the engine speed, load, variable valve timing angle, water temperature, intake manifold temperature, residual oil film on the inner wall of the combustion chamber, air-fuel ratio of the exhaust gas and preset throttle opening involved in this application are all obtained with full authorization.

[0089] It should be understood that the "plurality" mentioned in this article refers to two or more. "And / or" describes the association relationship of the associated objects, indicating that there can be three relationships. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. The character " / " generally indicates that the associated objects are in an "or" relationship.

[0090] It should be noted that the terms "first", "second", etc. (if any) in the specification and claims of the present application are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present application. On the contrary, they are merely examples of devices and methods consistent with some aspects of the present application as detailed in the appended claims.

[0091] The above description is only an exemplary embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions, improvements, etc. made within the principles of the present application shall be included in the protection scope of the present application.

Claims

1. A method for controlling an engine, characterized in that: The method comprises: Obtain the engine speed, load, variable valve timing angle, water temperature and intake manifold temperature before shutdown; Calculating the amount of oil film residue on the inner wall surface of the combustion chamber when the engine is stopped based on the speed, the load, the variable valve timing angle, the water temperature, and the intake manifold temperature; calculating a preset throttle opening when the engine is stopped based on the residual oil film amount and the engine speed, wherein the preset throttle opening is considered to satisfy the intake air amount required during the engine stop process; Controlling the engine to start a stop ventilation operation at the preset throttle opening; Continuously obtaining the air-fuel ratio of the gas exhausted by the engine during the shutdown ventilation operation; determining, based on the air-fuel ratio, whether the intake air amount of the engine reaches the intake air amount required during the engine shutdown process; In response to the intake air amount of the engine reaching the intake air amount required during the engine stop process, the engine is stopped by controlling the motor.

2. The method according to claim 1, characterized in that The calculating of a preset throttle opening when the engine is stopped based on the residual oil film amount and the rotation speed of the engine includes: Calculating the intake air volume required during the engine shutdown process based on the oil film residual amount and the engine speed; A preset throttle opening when the engine is stopped is calculated based on the intake air amount.

3. The method according to claim 1, characterized in that The controlling the engine to start the stop ventilation operation at the preset throttle opening comprises: The fuel cutoff of the engine is controlled, the throttle is adjusted to the preset throttle opening and the engine is controlled to rotate at a preset speed through the motor.

4. The method according to claim 1, characterized in that: The step of continuously obtaining the air-fuel ratio of the gas exhausted by the engine during the shutdown ventilation operation includes: Continuously obtaining the oxygen concentration in the gas exhausted by the engine during the shutdown ventilation operation; An air-fuel ratio of the engine exhaust gas is calculated based on the oxygen concentration.

5. The method according to claim 1, characterized in that The determining, based on the air-fuel ratio, whether the intake air amount of the engine reaches the intake air amount required during the engine shutdown process includes: In response to the air-fuel ratio being lower than an air-fuel ratio threshold, determining that the engine has not reached the intake air amount required during the engine shutdown process, the air-fuel ratio threshold being the air-fuel ratio when the engine is in a stable operating state; In response to the air-fuel ratio curve being higher than the air-fuel ratio threshold, it is determined that the engine has achieved a required intake air amount during the engine shutdown process.

6. The method according to claim 1, characterized in that The calculation of the oil film residual amount on the inner wall surface of the combustion chamber when the engine is stopped based on the speed, the load, the variable valve timing angle, the water temperature and the intake manifold temperature includes: The rotational speed, the load, the variable valve timing angle, the water temperature and the intake manifold temperature are input into a preset model for calculating the residual amount of oil film on the inner wall of the combustion chamber to obtain the residual amount of oil film on the inner wall of the combustion chamber.

7. An engine control device, characterized in that: The device comprises: A first acquisition module is used to acquire the speed, load, variable valve timing angle, water temperature and intake manifold temperature of the engine before shutdown; A first calculation module, configured to calculate the amount of residual oil film on the inner wall surface of the combustion chamber when the engine is stopped based on the rotation speed, the load, the variable valve timing angle, the water temperature, and the intake manifold temperature; a second calculation module, configured to calculate a preset throttle opening when the engine is stopped based on the residual oil film amount and the engine speed, wherein the preset throttle opening is considered to satisfy the intake air volume required during the engine stop process; A first control module, used for controlling the engine to start the shutdown ventilation operation at the preset throttle opening; A second acquisition module, used for continuously acquiring the air-fuel ratio of the gas exhausted by the engine during the shutdown ventilation operation; A judgment module, used for judging whether the intake air amount of the engine reaches the intake air amount required during the engine shutdown process based on the air-fuel ratio; The second control module is used for controlling the engine to stop through a motor in response to the intake air volume of the engine reaching the intake air volume required during the engine stop process.

8. The device according to claim 7, characterized in that The second calculation module is used to calculate the intake air volume required during the engine shutdown process based on the oil film residual amount and the engine speed; A preset throttle opening when the engine is stopped is calculated based on the intake air amount.

9. A computer program product, comprising computer instructions, which, when executed by a processor, implement the steps of the engine control method according to any one of claims 1 to 6.

10. A non-transitory computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, which is loaded and executed by a processor to implement the engine control method according to any one of claims 1 to 6.

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