Control method, device and storage medium of engine

Abstract

The application discloses a control method and device of an engine and a storage medium, and belongs to the technical field of vehicle control. The method comprises the following steps: correcting an initial EGR rate by using the intake humidity of the engine to obtain a corrected EGR rate; calculating the water content of the engine intake air based on the intake flow, intake temperature, intake humidity and the corrected EGR rate of the engine; calculating the water density of the engine intake air based on the water content of the engine intake air; calculating the water density of the intercooled mixed gas with the second preset humidity based on the temperature of the intercooled mixed gas, the second preset humidity is 100%, and the first preset humidity is less than the second preset humidity; and in response to the water density of the engine intake air being greater than or equal to the water density of the intercooled mixed gas with the second preset humidity, the EGR rate is controlled to be reduced at the first preset step. The method can avoid engine misfire caused by condensed water when the humidity of the air entering the engine is high, thereby ensuring the safety of the engine and the vehicle.

Description

Technical Field

[0001] This application relates to the field of vehicle control technology, and in particular to an engine control method, device and storage medium. Background Technology

[0002] As energy consumption and environmental pollution gain increasing attention, fuel consumption standards for vehicles are becoming increasingly stringent. To meet these standards, the engine's maximum thermal efficiency needs to be increased to over 45%. To achieve this, EGR (Exhaust Gas Recirculation) is required. The main components of the exhaust gas in EGR are carbon dioxide and water vapor.

[0003] For turbocharged intercooled engines using EGR technology, when the humidity of the air entering the engine is high, liquid condensate will form after the intercooler. When this condensate enters the engine combustion chamber with the intake airflow and participates in combustion, it can cause misfire, resulting in a short-term loss of engine power. Therefore, preventing engine misfire caused by condensate when the humidity of the air entering the engine is high is crucial for ensuring the safety of the engine and the vehicle. Summary of the Invention

[0004] This application provides an engine control method, device, and storage medium, which can be used to prevent engine misfire caused by condensation when the humidity of the air entering the engine is high. The technical solution is as follows: On one hand, embodiments of this application provide an engine control method, the method comprising: The engine's intake air flow rate, intake air temperature, intake air humidity, initial EGR rate, intercooled gas mixture temperature, EGR gas temperature, and EGR gas humidity are obtained, wherein the initial EGR rate is the engine's EGR rate at a first preset humidity. The initial EGR rate is corrected by the intake air humidity to obtain the corrected EGR rate; The water content of the engine intake air is calculated based on the intake air flow rate, the intake air temperature, the intake air humidity, and the corrected EGR rate. Calculate the water density of the engine intake air based on the water content of the engine intake air; The water density of the intercooled mixed gas after the temperature of the intercooled mixed gas is calculated based on the second preset humidity, where the second preset humidity is 100% and the first preset humidity is less than the second preset humidity. In response to the water density of the engine intake air being greater than or equal to the water density of the intercooled after-mixture gas with the second preset humidity, the EGR rate is controlled to decrease by a first preset step size.

[0005] On the other hand, an engine control device is provided, the device comprising: The acquisition module is used to acquire the engine's intake air flow rate, intake air temperature, intake air humidity, initial EGR rate, intercooled gas mixture temperature, EGR gas temperature and EGR gas humidity, wherein the initial EGR rate is the engine's EGR rate at a first preset humidity. The correction module is used to correct the initial EGR rate based on the intake air humidity to obtain the corrected EGR rate. The first calculation module is used to calculate the water content of the engine intake air based on the intake air flow rate, the intake air temperature, the intake air humidity and the corrected EGR rate; The second calculation module is used to calculate the water density of the engine intake air based on the water content of the engine intake air. The third calculation module is used to calculate the water density of the intercooled mixed gas at a second preset humidity based on the temperature of the intercooled mixed gas. The second preset humidity is 100%, and the first preset humidity is less than the second preset humidity. The control module is configured to control the EGR rate to decrease in response to the water density of the engine intake air being greater than or equal to the water density of the intercooled after-mixture gas at the second preset humidity, with a first preset step size.

[0006] On the other hand, a non-transitory computer-readable storage medium is also provided, characterized in that the computer-readable storage medium stores a computer program, which is loaded and executed by a processor to implement any of the above-described engine control methods.

[0007] On the other hand, a computer program product is also provided, the computer program product including computer instructions, which, when executed by a processor, implement the steps of any of the above-described engine control methods.

[0008] The technical solution provided in this application brings at least the following beneficial effects: This application calculates the water content of the engine intake air by acquiring intake air flow rate, intake air temperature, intake air humidity, and a corrected EGR rate; then calculates the water density of the engine intake air based on the water content; and calculates the water density of the intercooled after-mixture at a second preset humidity based on the intercooled after-mixture temperature; when the water density of the engine intake air is greater than or equal to the water density of the intercooled after-mixture at the second preset humidity, the EGR rate is controlled to decrease by a first preset step size. This avoids engine misfire caused by condensation when the humidity of the air entering the engine is high, thereby ensuring the safety of the engine and the vehicle. Attached Figure Description

[0009] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0010] Figure 1 This is a schematic diagram of an implementation environment provided in an embodiment of this application; Figure 2 This is a flowchart of an engine control method provided in an embodiment of this application; Figure 3 This is a schematic diagram of the structure of an engine control device provided in an embodiment of this application. Detailed Implementation

[0011] To make the objectives, technical solutions, and advantages of this application clearer, the embodiments of this application will be described in further detail below with reference to the accompanying drawings.

[0012] This application provides an engine control method, please refer to... Figure 1 The diagram illustrates the implementation environment of the method provided in this application embodiment. This implementation environment may include: an ECU (Engine Control Unit) 11, a MAF (Mass Air Flow) sensor 12, an IAT (Intake Air Temperature) sensor 13, a first humidity sensor 14, a first temperature sensor 15, a second temperature sensor 16, a second humidity sensor 17, a MAP (Manifold Absolute Pressure) sensor 18, and an EGR valve drive motor 19.

[0013] Optionally, the MAF sensor 12 is installed on the intake manifold after the air filter and before the throttle valve to obtain the engine's intake air flow and send it to the ECU 11; the IAT sensor 13 can be integrated inside the MAF or installed on the intake manifold to obtain the engine's intake air temperature and send it to the ECU 11; the first humidity sensor 14 is installed on the intake manifold after the air filter and before the intercooler to obtain the engine's intake air humidity and send it to the ECU 11; the first temperature sensor 15 is installed on the intake manifold at the intercooler outlet and before the throttle valve to obtain the temperature of the air-fuel mixture after intercooling and send it to the ECU 11.

[0014] For example, the second temperature sensor 16 is installed on the EGR line after the EGR valve and before it merges with the intake manifold, for acquiring the EGR gas temperature and sending it to the ECU 11; the second humidity sensor 17 is installed on the EGR line after the EGR valve and before it merges with the intake manifold, for acquiring the EGR gas temperature and sending it to the ECU 11; the MAP sensor 18 is installed on the engine's intake manifold, for acquiring the intake manifold absolute pressure and sending it to the ECU 11; the EGR valve drive motor 19 is used to receive the PWM (Pulse Width Modulation) signal output by the ECU 11, and control the valve opening according to the PWM signal, thereby controlling the change of the EGR rate.

[0015] In one possible implementation, the ECU11, MAF sensor 12, IAT sensor 13, first humidity sensor 14, first temperature sensor 15, second temperature sensor 16, second humidity sensor 17, MAP sensor 18, and EGR valve drive motor 19 establish a communication connection via a wired or wireless network.

[0016] Based on the above Figure 1 The implementation environment shown in this application provides an engine control method, such as... Figure 2 As shown, taking the application of this method to an ECU as an example, the method includes steps 201-206.

[0017] In step 201, the ECU acquires the engine's intake air flow, intake air temperature, intake air humidity, initial EGR rate, intercooled mixture temperature, EGR gas temperature, and EGR gas humidity. The initial EGR rate is the engine's EGR rate at a first preset humidity.

[0018] In one possible implementation, the ECU acquires the engine's intake air flow, intake air temperature, intake air humidity, intercooled after-mixture temperature, EGR gas temperature, and EGR gas humidity in the following ways: the ECU acquires the engine's intake air flow via a MAF sensor, wherein the MAF sensor is installed on the intake manifold after the air filter and before the throttle valve; the ECU acquires the engine's intake air temperature via an IAT sensor, wherein the IAT sensor can be integrated inside the MAF or installed on the intake manifold; the ECU acquires the engine's intake air humidity via a first humidity sensor, wherein the first humidity sensor is installed on the intake manifold after the air filter and before the intercooler; the ECU acquires the intercooled after-mixture temperature via a first temperature sensor, wherein the first temperature sensor is installed on the intake manifold at the intercooler outlet and before the throttle valve; the ECU acquires the EGR gas temperature via a second temperature sensor, wherein the second temperature sensor is installed on the EGR line after the EGR valve and before it merges with the intake manifold; the ECU acquires the EGR gas temperature via a second humidity sensor, wherein the second humidity sensor is installed on the EGR line after the EGR valve and before it merges with the intake manifold.

[0019] For example, the ECU obtains the initial EGR rate by using the engine's intake air humidity at a first preset humidity level as the initial EGR rate. The engine's intake air humidity at the first preset humidity level can be predetermined, and the first preset humidity level can be set empirically.

[0020] In step 202, the ECU corrects the initial EGR rate based on the intake air humidity to obtain the corrected EGR rate.

[0021] Optionally, after obtaining the engine's intake air humidity, the ECU corrects the initial EGR rate based on the intake air humidity to obtain a corrected EGR rate. This includes: the ECU determining the EGR rate corresponding to the current engine's intake air humidity based on the correspondence between engine intake air humidity and EGR rate, and using this as the corrected EGR rate. For example, the correspondence between engine intake air humidity and EGR rate can be preset.

[0022] Based on a predetermined relationship between engine intake air humidity and EGR rate, the initial EGR rate is corrected in real time using the current engine intake air humidity. The corrected EGR rate is then used to calculate the water content of the engine intake air, ensuring that the EGR rate used to calculate the water content of the engine intake air is the same as the current engine intake air humidity in real time. This improves the accuracy of the calculated water content of the engine intake air and the determination of whether there is a risk of condensation.

[0023] In step 203, the ECU calculates the water content of the engine intake air based on the intake air flow rate, intake air temperature, intake air humidity, and the corrected EGR rate.

[0024] In one possible implementation, after obtaining the engine's intake air flow rate, intake air temperature, intake air humidity, and corrected EGR rate, the ECU calculates the water content of the engine intake air based on the intake air flow rate, intake air temperature, intake air humidity, and corrected EGR rate, including: calculating the water content of the fresh air in the engine intake air based on the intake air flow rate, intake air temperature, and intake air humidity; calculating the water content of the EGR gas in the engine intake air based on the intake air flow rate, EGR gas temperature, EGR gas humidity, and corrected EGR rate; and calculating the water content of the engine intake air based on the water content of the fresh air in the engine intake air and the water content of the EGR gas in the engine intake air.

[0025] For example, the ECU calculates the water content of the fresh air in the engine intake based on the intake air flow rate, intake air temperature, and intake air humidity, including: calculating a first saturated water vapor pressure based on the intake air temperature; calculating a first actual water vapor pressure based on the first saturated water vapor pressure and the intake air humidity; calculating a first water vapor density based on the first actual water vapor pressure and the intake air temperature; and calculating the water content of the fresh air in the engine intake based on the first water vapor density and the intake air flow rate.

[0026] Optionally, the ECU calculates the first saturated vapor pressure based on the intake air temperature, including: substituting the engine's intake air temperature into the formula for calculating the first saturated vapor pressure to obtain the first saturated vapor pressure. The formula for calculating the first saturated vapor pressure is shown below:

[0027] This refers to the engine's intake air temperature, which can be expressed in °C (degrees Celsius). This is the first saturated vapor pressure, and the unit can be kPa (kilopascal).

[0028] In one possible implementation, after calculating the first saturated vapor pressure, the ECU calculates the first actual vapor pressure based on the first saturated vapor pressure and the intake air humidity. This includes: the ECU multiplying the first saturated vapor pressure by the engine's intake air humidity, and using the result as the first actual vapor pressure. Optionally, the unit of the first actual vapor pressure can be kPa, and the engine's intake air humidity can be a number between 0 and 1.

[0029] For example, after calculating the first actual water vapor pressure, the ECU calculates the first water vapor density based on the first actual water vapor pressure and the intake air temperature. This includes: the ECU substituting the first actual water vapor pressure and the engine's intake air temperature into the formula for calculating the first water vapor density to obtain the first water vapor density. The formula for calculating the first water vapor density is as follows:

[0030] This is the first actual water vapor pressure, and the unit can be kPa; The density of water vapor is the first unit, which can be kg / m³ (kilograms per cubic meter). Let be the gas constant of water vapor. The value can be 461.5 J / (kg·K) (joules / (kg·Kelvin)).

[0031] Optionally, after calculating the first water vapor density, the ECU calculates the water content of the fresh air in the engine intake based on the first water vapor density and the intake air flow rate. This includes: the ECU substituting the first water vapor density and the engine intake air flow rate into the formula for calculating the water content of the fresh air to obtain the water content of the fresh air. The formula for calculating the water content of the fresh air is as follows:

[0032] The water content of fresh air, where the unit can be kg / s (kilograms per second). This refers to the engine's intake airflow, which can be measured in kg / s. This is the dry air density, used to convert the engine's intake airflow from a mass-based flow rate to a volume-based flow rate. The value can be 1.225 kg / m³ (kilograms per cubic meter).

[0033] For example, after calculating the water content of the fresh air, the ECU calculates the water content of the EGR gas in the engine intake air based on the intake air flow rate, EGR gas temperature, EGR gas humidity, and the corrected EGR rate, including: calculating the EGR flow rate based on the intake air flow rate and the corrected EGR rate; calculating the second saturated vapor pressure based on the EGR gas temperature; calculating the second actual vapor pressure based on the second saturated vapor pressure and the EGR gas humidity; calculating the second water vapor density based on the second actual vapor pressure and the EGR gas temperature; and calculating the water content of the EGR gas in the engine intake air based on the second water vapor density and the EGR flow rate.

[0034] Optionally, the ECU calculates the EGR flow rate based on the intake airflow and the corrected EGR rate, including: the ECU substituting the engine's intake airflow and the corrected EGR rate into the formula for calculating the EGR flow rate to obtain the EGR flow rate. The formula for calculating the EGR flow rate is as follows:

[0035] EGR flow rate, the unit can be kg / s; This is the corrected EGR rate, a number between 0 and 1.

[0036] Optionally, after calculating the EGR flow rate, the ECU calculates the second saturated water vapor pressure based on the EGR gas temperature, including: substituting the EGR gas temperature into the formula for calculating the second saturated water vapor pressure to obtain the second saturated water vapor pressure. The formula for calculating the second saturated water vapor pressure is shown below:

[0037] The temperature of the EGR gas can be expressed in °C. This is the second saturated vapor pressure, and the unit can be kPa.

[0038] In one possible implementation, after calculating the second saturated vapor pressure, the ECU calculates the second actual vapor pressure based on the second saturated vapor pressure and the EGR gas humidity. This includes: the ECU calculating the result of multiplying the second saturated vapor pressure by the EGR gas humidity, and using the result as the second actual vapor pressure. Optionally, the unit of the second actual vapor pressure can be kPa, and the EGR gas humidity can be a number between 0 and 1.

[0039] For example, after calculating the second actual water vapor pressure, the ECU calculates the second water vapor density based on the second actual water vapor pressure and the EGR gas temperature. This includes: the ECU substituting the second actual water vapor pressure and the EGR gas temperature into the formula for calculating the second water vapor density to obtain the second water vapor density. The formula for calculating the second water vapor density is as follows:

[0040] This is the second actual water vapor pressure, and the unit can be kPa; This is the second water vapor density, and the unit can be kg / m³.

[0041] Optionally, after calculating the second water vapor density, the ECU calculates the water content of the EGR gas in the engine intake air based on the second water vapor density and the EGR flow rate. This includes: the ECU substituting the second water vapor density and the EGR flow rate into the formula for calculating the water content of the EGR gas to obtain the water content of the EGR gas. The formula for calculating the water content of the EGR gas is as follows:

[0042] The water content of the EGR gas is given by the unit kg / s (kilograms per second).

[0043] In one possible implementation, after calculating the water content of the fresh air in the engine intake and the water content of the EGR gas, the water content of the engine intake is calculated based on the water content of the fresh air in the engine intake and the water content of the EGR gas in the engine intake. This includes: calculating the sum of the water content of the fresh air in the engine intake and the water content of the EGR gas, and using the calculation result as the water content of the engine intake.

[0044] In step 204, the ECU calculates the water density of the engine intake air based on the water content of the engine intake air.

[0045] For example, after calculating the water content of the engine intake air, the ECU calculates the water density of the engine intake air based on the water content of the engine intake air, including: obtaining the volumetric flow rate of fresh air in the engine intake air and the volumetric flow rate of EGR gas in the engine intake air; calculating the sum of the volumetric flow rate of fresh air in the engine intake air and the volumetric flow rate of EGR gas in the engine intake air as the total volumetric flow rate of the mixed gas; and calculating the water density of the engine intake air based on the water content of the engine intake air and the total volumetric flow rate.

[0046] Optionally, the ECU acquires the volumetric flow rate of fresh air and EGR gas in the engine intake air, including: the ECU acquiring the intake manifold absolute pressure via a MAP sensor, wherein the MAP sensor is mounted on the engine's intake manifold; and substituting the engine's intake air flow rate, intake air temperature, intake manifold absolute pressure, and air gas constant into the formula for calculating the volumetric flow rate of fresh air to obtain the volumetric flow rate of fresh air. The formula for calculating the volumetric flow rate of fresh air is shown below:

[0047] The volumetric flow rate of fresh air, the unit can be... (cubic meters per second); Let be the gas constant of air. The value can be 287 J / (kg·K); This is the absolute pressure in the intake manifold, and the unit can be K (Kelvin).

[0048] In one possible implementation, the EGR flow rate, EGR gas temperature, intake manifold absolute pressure, and air gas constant are substituted into the formula for calculating the volumetric flow rate of the EGR gas to obtain the volumetric flow rate of the EGR gas. The formula for calculating the volumetric flow rate of the EGR gas is shown below:

[0049] This refers to the volumetric flow rate of the EGR gas, and the unit can be... .

[0050] For example, after calculating the volumetric flow rate of fresh air and EGR gas in the engine intake, the ECU calculates the sum of the volumetric flow rates of fresh air and EGR gas in the engine intake, and uses the result as the total volumetric flow rate of the gas mixture. Then, based on the water content and total volumetric flow rate of the engine intake, the ECU calculates the water density of the engine intake, including: dividing the water content of the engine intake by the total volumetric flow rate of the gas mixture, and using the result as the water density of the engine intake. The unit of the water density of the engine intake can be kg / m³.

[0051] In step 205, the ECU calculates the water density of the intercooled gas mixture based on the temperature of the intercooled gas mixture after the intercooling, with the second preset humidity being 100%, and the first preset humidity being less than the second preset humidity.

[0052] Optionally, after obtaining the temperature of the intercooled gas mixture, the water density of the intercooled gas mixture at the second preset humidity is calculated based on the intercooled gas mixture temperature, including: calculating the third saturated vapor pressure based on the intercooled gas mixture temperature; calculating the third actual vapor pressure based on the third saturated vapor pressure and the second preset humidity; and calculating the water density of the intercooled gas mixture at the second preset humidity based on the third actual vapor pressure and the intercooled gas mixture temperature. In one possible implementation, the second preset humidity is 1, and the first preset humidity is less than the second preset humidity.

[0053] For example, the ECU calculates the third saturated vapor pressure based on the temperature of the air-fuel mixture after intercooling, including: substituting the temperature of the air-fuel mixture after intercooling into the formula for calculating the third saturated vapor pressure to obtain the third saturated vapor pressure. The formula for calculating the third saturated vapor pressure is as follows:

[0054] This refers to the temperature of the mixed gas after intercooling, and the unit can be ℃. This is the third saturated vapor pressure, and the unit can be kPa.

[0055] In one possible implementation, after calculating the third saturated vapor pressure, the ECU calculates the third actual vapor pressure based on the third saturated vapor pressure and the second preset humidity. This includes: the ECU calculating the result of multiplying the third saturated vapor pressure by the second preset humidity, and using the result as the third actual vapor pressure. Optionally, the unit of the third actual vapor pressure can be kPa.

[0056] For example, after calculating the third actual water vapor pressure, the ECU calculates the water density of the intercooled gas mixture at the second preset humidity based on the third actual water vapor pressure and the temperature of the intercooled gas mixture after cooling. This includes: the ECU substituting the third actual water vapor pressure and the temperature of the intercooled gas mixture after cooling into the formula for calculating the water density of the intercooled gas mixture after cooling to obtain the water density of the intercooled gas mixture at the second preset humidity. The formula for calculating the water density of the intercooled gas mixture after cooling is as follows:

[0057] This is the third actual water vapor pressure, and the unit can be kPa; The water density of the intercooled mixed gas at the second preset humidity can be expressed in kg / m³.

[0058] In step 206, in response to the water density of the engine intake air being greater than or equal to the water density of the intercooled after-mixture at a second preset humidity, the ECU controls the EGR rate to decrease by a first preset step size.

[0059] Optionally, after obtaining the water density of the engine intake air and the water density of the intercooled after-mixture at the second preset humidity, the water density of the engine intake air is compared with the water density of the intercooled after-mixture at the second preset humidity. In response to the water density of the engine intake air being greater than or equal to the water density of the intercooled after-mixture at the second preset humidity, the ECU controls the EGR rate to decrease by a first preset step size; in response to the water density of the engine intake air being less than the water density of the intercooled after-mixture at the second preset humidity, the EGR rate is controlled to increase by a second preset step size until the EGR rate reaches a preset bench calibration value.

[0060] In one possible implementation, if the water density of the engine intake air is greater than or equal to the water density of the intercooled after-mixture at a second preset humidity, the ECU controls the EGR rate to decrease by a first preset step size. This includes: the ECU outputting a PWM signal with a first preset duty cycle to the EGR valve drive motor to control the valve opening to decrease, thereby reducing the EGR rate by the first preset step size. Optionally, the first preset duty cycle is a positive duty cycle, which can be determined based on the first preset step size. The first preset step size and the correspondence between the first preset duty cycle and the first preset step size can be set empirically.

[0061] For example, if the water density of the engine intake air is less than the water density of the intercooled after-mixture at a second preset humidity, the EGR rate is controlled to increase by a second preset step size until the EGR rate reaches a preset bench calibration value. This includes: the ECU outputting a PWM signal with a second preset duty cycle to the EGR valve drive motor to control the valve opening to increase, thereby increasing the EGR rate by the second preset step size until the EGR rate reaches a preset EGR rate threshold. Then, the ECU stops outputting the PWM signal to the EGR valve drive motor, maintaining the current EGR rate. In one possible implementation, the second preset duty cycle is an inverse duty cycle. The second preset duty cycle can be determined based on the second preset step size, and the second preset step size and its correspondence can be set empirically.

[0062] This embodiment calculates the water content of the engine intake air by acquiring intake air flow rate, intake air temperature, intake air humidity, and a corrected EGR rate; then, it calculates the water density of the engine intake air based on the water content; and finally, it calculates the water density of the intercooled after-mixture at a second preset humidity based on the intercooled after-mixture temperature. When the water density of the engine intake air is greater than or equal to the water density of the intercooled after-mixture at the second preset humidity, the EGR rate is controlled to decrease by a first preset step size. This avoids engine misfires caused by condensation when the humidity of the air entering the engine is high, thereby ensuring the safety of the engine and the vehicle.

[0063] See Figure 3 This application provides an engine control device, which includes: The acquisition module 301 is used to acquire the engine's intake air flow, intake air temperature, intake air humidity, initial EGR rate, intercooled gas mixture temperature, EGR gas temperature and EGR gas humidity, wherein the initial EGR rate is the engine's EGR rate at a first preset humidity. Correction module 302 is used to correct the initial EGR rate by the intake air humidity to obtain the corrected EGR rate; The first calculation module 303 is used to calculate the water content of the engine intake air based on the intake air flow, intake air temperature, intake air humidity and the corrected EGR rate; The second calculation module 304 is used to calculate the water density of the engine intake air based on the water content of the engine intake air. The third calculation module 305 is used to calculate the water density of the intercooled mixed gas based on the temperature of the intercooled mixed gas after the second preset humidity, where the second preset humidity is 100% and the first preset humidity is less than the second preset humidity. The control module 306 is used to control the EGR rate to decrease in response to the water density of the intercooled after-mixture gas being greater than or equal to the water density of the engine intake air being greater than or equal to the water density of the intercooled after-mixture gas being a second preset humidity, with a first preset step size.

[0064] In one possible implementation, the first calculation module 303 is used to calculate the water content of the fresh air in the engine intake based on the intake air flow rate, intake air temperature, and intake air humidity; calculate the water content of the EGR gas in the engine intake based on the intake air flow rate, EGR gas temperature, EGR gas humidity, and the corrected EGR rate; and calculate the water content of the engine intake based on the water content of the fresh air in the engine intake and the water content of the EGR gas in the engine intake.

[0065] In one possible implementation, the first calculation module 303 is used to calculate a first saturated water vapor pressure based on the intake air temperature; calculate a first actual water vapor pressure based on the first saturated water vapor pressure and the intake air humidity; calculate a first water vapor density based on the first actual water vapor pressure and the intake air temperature; and calculate the water content of the fresh air in the engine intake based on the first water vapor density and the intake air flow rate.

[0066] In one possible implementation, the first calculation module 303 is used to calculate the EGR flow rate based on the intake air flow rate and the corrected EGR rate; calculate the second saturated water vapor pressure based on the EGR gas temperature; calculate the second actual water vapor pressure based on the second saturated water vapor pressure and the EGR gas humidity; calculate the second water vapor density based on the second actual water vapor pressure and the EGR gas temperature; and calculate the water content of the EGR gas in the engine intake air based on the second water vapor density and the EGR flow rate.

[0067] In one possible implementation, the third calculation module 305 is used to calculate the third saturated vapor pressure based on the temperature of the intercooled mixed gas; calculate the third actual vapor pressure based on the third saturated vapor pressure and the second preset humidity; and calculate the water density of the intercooled mixed gas with the second preset humidity based on the third actual vapor pressure and the temperature of the intercooled mixed gas.

[0068] In one possible implementation, the second calculation module 304 is used to obtain the volumetric flow rate of fresh air in the engine intake and the volumetric flow rate of EGR gas in the engine intake; calculate the sum of the volumetric flow rate of fresh air in the engine intake and the volumetric flow rate of EGR gas in the engine intake as the total volumetric flow rate of the mixed gas; and calculate the water density of the engine intake based on the water content and the total volumetric flow rate.

[0069] In one possible implementation, the first calculation module 303 is further configured to control the EGR rate to increase by a second preset step size in response to the water density of the engine intake air being less than the water density of the intercooled after-mixture gas at a second preset humidity, until the EGR rate reaches a preset bench calibration value.

[0070] This device calculates the water content of the engine intake air by acquiring intake air flow rate, intake air temperature, intake air humidity, and a corrected EGR rate; then it calculates the water density of the engine intake air based on the water content; and further calculates the water density of the intercooled after-mixture at a second preset humidity based on the intercooled after-mixture temperature. If the water density of the engine intake air is greater than or equal to the water density of the intercooled after-mixture at the second preset humidity, the EGR rate is controlled to decrease by a first preset step size. This prevents engine misfires caused by condensation when the humidity of the air entering the engine is high, thereby ensuring the safety of the engine and the vehicle.

[0071] It should be noted that the apparatus provided in the above embodiments is only illustrated by the division of the above functional modules. In practical applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above. In addition, the apparatus and method embodiments provided in the above embodiments belong to the same concept, and their specific implementation process can be found in the method embodiments, which will not be repeated here.

[0072] In an exemplary embodiment, a computer-readable storage medium is also provided, which stores at least one computer program that is loaded and executed by a processor of a computer device to enable the computer to implement any of the above-described engine control methods.

[0073] In one possible implementation, the aforementioned computer-readable storage medium may be a read-only memory (ROM), a random access memory (RAM), a compact disc read-only memory (CD-ROM), magnetic tape, floppy disk, and optical data storage device, etc.

[0074] In an exemplary embodiment, a computer program product or computer program is also provided, which includes computer instructions stored in a computer-readable storage medium. A processor of a computer device reads the computer instructions from the computer-readable storage medium and executes the computer instructions, causing the computer device to perform any of the above-described engine control methods.

[0075] It should be noted that all information (including but not limited to user equipment information, user personal information, etc.), data (including but not limited to data used for analysis, data stored, data displayed, etc.), and signals involved in this application are authorized by the user or fully authorized by all parties, and the collection, use, and processing of related data must comply with the relevant laws, regulations, and standards of the relevant countries and regions. For example, the engine intake airflow, intake air temperature, intake air humidity, initial EGR rate, intercooled after-mixture temperature, EGR gas temperature, EGR gas humidity, corrected EGR rate, engine intake air water content, engine intake air water density, and the water density of the intercooled after-mixture at the second preset humidity involved in this application were all obtained with full authorization.

[0076] It should be understood that "multiple" as used in this article refers to two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone. The character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0077] It should be noted that the terms "first," "second," etc. (if applicable) in the specification and claims of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.

[0078] The above description is merely an exemplary embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the principles of this application should be included within the protection scope of this application.

Claims

1. A method for controlling an engine, characterized in that, The method includes: The engine's intake air flow rate, intake air temperature, intake air humidity, initial EGR rate, intercooled gas mixture temperature, EGR gas temperature, and EGR gas humidity are obtained, wherein the initial EGR rate is the engine's EGR rate at a first preset humidity. The initial EGR rate is corrected by the intake air humidity to obtain the corrected EGR rate; The water content of the engine intake air is calculated based on the intake air flow rate, the intake air temperature, the intake air humidity, and the corrected EGR rate. Calculate the water density of the engine intake air based on the water content of the engine intake air; The water density of the intercooled mixed gas after the temperature of the intercooled mixed gas is calculated based on the second preset humidity, where the second preset humidity is 100% and the first preset humidity is less than the second preset humidity. In response to the water density of the engine intake air being greater than or equal to the water density of the intercooled after-mixture gas with the second preset humidity, the EGR rate is controlled to decrease by a first preset step size.

2. The method according to claim 1, characterized in that, The calculation of the water content in the engine intake air based on the intake air flow rate, the intake air temperature, the intake air humidity, and the corrected EGR rate includes: The water content of the fresh air in the engine intake is calculated based on the intake flow rate, the intake temperature, and the intake humidity. The water content of the EGR gas in the engine intake air is calculated based on the intake air flow rate, the EGR gas temperature, the EGR gas humidity, and the corrected EGR rate. The water content of the engine intake is calculated based on the water content of the fresh air in the engine intake and the water content of the EGR gas in the engine intake.

3. The method according to claim 2, characterized in that, The calculation of the water content of the fresh air in the engine intake based on the intake flow rate, the intake temperature, and the intake humidity includes: Calculate the first saturated vapor pressure based on the inlet air temperature; The first actual water vapor pressure is calculated based on the first saturated water vapor pressure and the inlet air humidity. The first water vapor density is calculated based on the first actual water vapor pressure and the inlet air temperature; The water content of the fresh air in the engine intake is calculated based on the first water vapor density and the intake flow rate.

4. The method according to claim 2, characterized in that, The calculation of the water content of EGR gas in the engine intake air based on the intake air flow rate, the EGR gas temperature, the EGR gas humidity, and the corrected EGR rate includes: Calculate the EGR flow rate based on the intake flow rate and the corrected EGR rate; Calculate the second saturated water vapor pressure based on the EGR gas temperature; The second actual water vapor pressure is calculated based on the second saturated water vapor pressure and the EGR gas humidity. The second water vapor density is calculated based on the second actual water vapor pressure and the EGR gas temperature; The water content of the EGR gas in the engine intake is calculated based on the second water vapor density and the EGR flow rate.

5. The method according to claim 1, characterized in that, The calculation of the water density of the intercooled gas mixture with the second preset humidity based on the temperature of the intercooled gas mixture includes: Calculate the third saturated water vapor pressure based on the temperature of the mixed gas after intercooling; The third actual water vapor pressure is calculated based on the third saturated water vapor pressure and the second preset humidity. The water density of the intermediate-cooled mixed gas with the second preset humidity is calculated based on the third actual water vapor pressure and the temperature of the intermediate-cooled mixed gas.

6. The method according to claim 1, characterized in that, The calculation of the water density of the engine intake air based on the water content of the engine intake air includes: The volumetric flow rate of fresh air in the engine intake and the volumetric flow rate of EGR gas in the engine intake are obtained. The sum of the volumetric flow rate of fresh air in the engine intake and the volumetric flow rate of EGR gas in the engine intake is calculated as the total volumetric flow rate of the mixed gas. The water density of the engine intake air is calculated based on the water content of the engine intake air and the total volumetric flow rate.

7. The method according to claim 1, characterized in that, After calculating the water content of the EGR gas in the engine intake air based on the intake air flow rate, the EGR gas temperature, the EGR gas humidity, and the corrected EGR rate, the method further includes: In response to the fact that the water density of the engine intake air is less than the water density of the intercooled after-mixture gas with the second preset humidity, the EGR rate is controlled to increase by a second preset step size until the EGR rate reaches a preset bench calibration value.

8. A control device for an engine, characterized in that, The device includes: The acquisition module is used to acquire the engine's intake air flow rate, intake air temperature, intake air humidity, initial EGR rate, intercooled gas mixture temperature, EGR gas temperature and EGR gas humidity, wherein the initial EGR rate is the engine's EGR rate at a first preset humidity. The correction module is used to correct the initial EGR rate based on the intake air humidity to obtain the corrected EGR rate. The first calculation module is used to calculate the water content of the engine intake air based on the intake air flow rate, the intake air temperature, the intake air humidity and the corrected EGR rate; The second calculation module is used to calculate the water density of the engine intake air based on the water content of the engine intake air. The third calculation module is used to calculate the water density of the intercooled mixed gas at a second preset humidity based on the temperature of the intercooled mixed gas. The second preset humidity is 100%, and the first preset humidity is less than the second preset humidity. The control module is configured to control the EGR rate to decrease in response to the water density of the engine intake air being greater than or equal to the water density of the intercooled after-mixture gas at the second preset humidity, with a first preset step size.

9. A computer program product comprising computer instructions that, when executed by a processor, implement the steps of the engine control method as claimed in any one of claims 1 to 7.

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 as described in any one of claims 1 to 7.

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