Control method, control device, and electronic device for an egr valve

Abstract

The application provides a control method, a control device and an electronic device of an EGR valve. The method comprises the following steps: obtaining a temperature after cooling and an EGR valve current opening; calculating a cooling efficiency of an EGR cooler; in the case that the cooling efficiency is less than or equal to a first preset threshold, obtaining a correction factor, calculating a product of the cooling efficiency, the correction factor and the EGR valve current opening to obtain an EGR valve target opening, and controlling the opening of the EGR valve to be the EGR valve target opening, wherein the correction factor is used to correct the opening of the EGR valve, and the cooling efficiency is the efficiency of the EGR cooler in cooling exhaust gas of an engine; and in the case that the cooling efficiency is greater than the first preset threshold and the temperature after cooling is greater than or equal to a second preset threshold, the EGR valve is controlled to be closed. Through the application, the problem that high-temperature exhaust gas causes the EGR valve to be burnt is solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of control of EGR valves, and in particular, to a control method of an EGR valve, a control device, a computer readable storage medium and an electronic device. BACKGROUND

[0002] An EGR system (Exhaust Gas Re-circulatuon, EGR system for short) mainly consists of an EGR cooler, a one-way valve, an electrically controlled EGR valve and the like. When a diesel engine adopts an electrically controlled high-pressure cooling EGR system, exhaust gas is directly introduced from the front of the turbine into the EGR cooler, cooled by the EGR cooler, and then flows into the intake pipe through the one-way valve and the electrically controlled EGR valve. The one-way valve is installed to avoid the backflow of fresh air when the intake pressure is higher than the pressure in front of the turbine under certain working conditions. During the operation of the diesel engine, if the EGR cooler fails, the temperature of the exhaust gas introduced from the front of the turbine will be too high, which will cause the EGR one-way valve and the electrically controlled EGR valve to melt, and cause engine failure. The existing method will monitor the cooling efficiency of the EGR cooler and report related faults, which will cause the engine to be limited in torque, but the engine is still running, and the high-temperature EGR exhaust gas flow will still pass through the one-way valve and the EGR valve. The EGR one-way valve and the EGR valve will be impacted or melted by high-temperature gas, the engine intake temperature will be abnormal, and the NOx emission will be abnormal.

[0003] Therefore, there is a need for a method to solve the problem of EGR valve melting. SUMMARY

[0004] The main purpose of the present application is to provide a control method of an EGR valve, a control device, a computer readable storage medium and an electronic device to at least solve the problem of EGR melting caused by high-temperature exhaust gas in the prior art.

[0005] In order to achieve the above object, according to one aspect of the present application, a control method of an EGR valve is provided, the EGR valve is included in an EGR system, the EGR system further comprises an EGR cooler and a one-way valve, the EGR cooler, the one-way valve and the EGR valve are sequentially connected in order, comprising: obtaining a gas temperature of exhaust gas of an engine after the exhaust gas is cooled by the EGR cooler, obtaining a cooled temperature, and obtaining a current opening degree of the EGR valve, obtaining an EGR valve current opening degree, wherein the EGR system is included in the engine; calculating a cooling efficiency of the EGR cooler, in a case that the cooling efficiency is less than or equal to a first preset threshold, obtaining a correction factor, calculating a product of the cooling efficiency, the correction factor and the EGR valve current opening degree, obtaining an EGR valve target opening degree, and in a case that the EGR valve target opening degree is different from the EGR valve current opening degree, controlling an opening degree of the EGR valve to be the EGR valve target opening degree, wherein the correction factor is used to correct the opening degree of the EGR valve, the cooling efficiency is an efficiency of the EGR cooler cooling the exhaust gas of the engine; in a case that the cooling efficiency is greater than the first preset threshold and the cooled temperature is greater than or equal to a second preset threshold, controlling the EGR valve to be closed.

[0006] Optionally, the cooling efficiency of the EGR cooler is calculated, comprising: obtaining a gas temperature of the exhaust gas of the engine before the exhaust gas is cooled by the EGR cooler, obtaining a pre-cooling temperature; calculating a ratio of the cooled temperature and the pre-cooling temperature, and calculating a difference between 1 and the ratio, obtaining the cooling efficiency.

[0007] Optionally, the correction factor is obtained, comprising: obtaining a plurality of historical cooled temperatures, a plurality of historical EGR valve flow rates and a historical correction factor corresponding to each of the historical cooled temperatures and each of the historical EGR valve flow rates, obtaining a one-to-one mapping relationship of the cooled temperature, the EGR valve flow rate and the correction factor; obtaining a current EGR valve flow rate, determining a historical correction factor corresponding to the cooled temperature and the current EGR valve flow rate through the one-to-one mapping relationship of the cooled temperature, the EGR valve flow rate and the correction factor, obtaining the correction factor.

[0008] Optionally, in the case that the cooling efficiency is less than or equal to the first preset threshold or in the case that the cooling efficiency is greater than the first preset threshold and the temperature after cooling is greater than or equal to the second preset threshold, the control method further comprises: in the case that the duration that the cooling efficiency is less than or equal to the first preset threshold is greater than or equal to a first preset time period, controlling the EGR cooler to generate an alarm signal to prompt the EGR cooler failure; in the case that the duration that the cooling efficiency is greater than the first preset threshold is greater than or equal to a second preset time period and the duration that the temperature after cooling is greater than or equal to the second preset threshold is greater than or equal to the second preset time period, controlling the EGR cooler to generate the alarm signal to prompt the EGR cooler failure.

[0009] Optionally, the control method further comprises: obtaining a current torque of the engine, wherein the EGR system is included in the engine; in the case that the cooling efficiency is less than or equal to the first preset threshold, calculating a product of the cooling efficiency, the correction factor and the current torque to obtain a target torque, and controlling the engine to operate at the target torque; in the case that the temperature after cooling is greater than or equal to the second preset threshold, controlling a speed of the engine to be an idle speed.

[0010] Optionally, the control method further comprises: obtaining a current speed and a current oil amount of the engine; determining a cooling efficiency threshold corresponding to the current speed and the current oil amount through a one-to-one mapping relationship of speed, oil amount and cooling efficiency threshold to obtain the first preset threshold, wherein the one-to-one mapping relationship of speed, oil amount and cooling efficiency threshold comprises a plurality of historical speeds and the historical oil amount and historical cooling efficiency threshold corresponding to each of the historical speeds; determining a temperature threshold corresponding to the current speed and the current oil amount through a one-to-one mapping relationship of speed, oil amount and temperature threshold after cooling to obtain the second preset threshold, wherein the one-to-one mapping relationship of speed, oil amount and temperature threshold after cooling comprises a plurality of historical speeds and the historical oil amount and historical temperature threshold corresponding to each of the historical speeds.

[0011] Optionally, obtaining a temperature of gas after exhaust gas of the engine is cooled by the EGR cooler to obtain the temperature after cooling comprises: in the case that a current opening degree of the EGR valve is greater than or equal to 0 and the engine in which the EGR system is located has no error, obtaining the temperature of the gas after the exhaust gas of the engine is cooled by the EGR cooler to obtain the temperature after cooling.

[0012] According to another aspect of the present application, there is provided a control device of an EGR valve, the EGR valve being included in an EGR system, the EGR system further comprising an EGR cooler and a one-way valve, the EGR cooler, the one-way valve and the EGR valve being connected in sequence, comprising: a first obtaining unit configured to obtain a temperature of exhaust gas of an engine after the exhaust gas passes through the EGR cooler, to obtain a cooled temperature, and to obtain a current opening degree of the EGR valve, to obtain an EGR valve current opening degree, wherein the EGR system is included in the engine; a first control unit configured to calculate a cooling efficiency of the EGR cooler, to obtain a correction factor in a case where the cooling efficiency is less than or equal to a first preset threshold, to calculate a product of the cooling efficiency, the correction factor and the EGR valve current opening degree, to obtain an EGR valve target opening degree, and to control an opening degree of the EGR valve to be the EGR valve target opening degree in a case where the EGR valve target opening degree is different from the EGR valve current opening degree, wherein the correction factor is used to correct the opening degree of the EGR valve, and the cooling efficiency is an efficiency of the EGR cooler cooling the exhaust gas of the engine; and a second control unit configured to control the EGR valve to be closed in a case where the cooling efficiency is greater than the first preset threshold and the cooled temperature is greater than or equal to a second preset threshold.

[0013] According to still another aspect of the present application, there is provided a computer-readable storage medium including a stored program, wherein the computer-readable storage medium is caused to perform any of the control methods when the program is executed.

[0014] According to yet another aspect of the present application, there is provided an electronic device comprising one or more processors, a memory, and one or more programs, wherein the one or more programs are stored in the memory and configured to be executed by the one or more processors, and the one or more programs include a program for performing any of the control methods.

[0015] The application obtains the temperature after cooling of the EGR cooler and the current opening degree of the EGR valve in the EGR system, calculates the cooling efficiency of the EGR cooler, and obtains the target opening degree of the EGR valve by calculating the product of the cooling efficiency, the correction factor and the current opening degree of the EGR valve when the cooling efficiency is less than the first preset threshold; controls the EGR valve to be closed when the cooling efficiency is greater than the first preset threshold and the temperature after cooling is greater than the second preset threshold. In this way, by monitoring the cooling efficiency and the temperature after cooling of the EGR cooler, when the EGR cooling efficiency is low or the temperature after cooling is too high, the flow of the EGR valve can be reduced or interrupted in time to avoid the EGR valve from being burned by hot gas. Compared with the prior art, in which the high-temperature EGR waste flow still flows through the EGR valve after the EGR cooler fails, the EGR valve can be burned, the application reduces or interrupts the flow of the high-temperature waste of the EGR valve in time to avoid further burning or damage of the EGR valve, and thus the problem of burning of the EGR valve caused by high-temperature waste gas in the prior art can be solved. BRIEF DESCRIPTION OF DRAWINGS

[0016] The accompanying drawings, which form a part of the present description, illustrate the present application and together with the written description serve to explain the application. In the drawings:

[0017] Figure 1 A hardware structure block diagram of a mobile terminal for executing the control method of the EGR valve is shown;

[0018] Figure 2 A flowchart of the control method of the EGR valve is shown;

[0019] Figure 3 A flowchart of the calculation method of the cooling efficiency in the control method of the EGR valve is shown;

[0020] Figure 4 An engine device schematic diagram to which the control method of the EGR valve is applied is shown;

[0021] Figure 5 A flowchart of a specific control method of the EGR valve is shown;

[0022] Figure 6 A structure block diagram of a control device of the EGR valve is shown.

[0023] Among the above-mentioned drawings, the following reference signs are included:

[0024] 102, processor; 104, memory; 106, transmission device; 108, input and output device; 1, EGR cooler front temperature sensor; 2, EGR cooler rear temperature sensor; 3, EGR cooler; 4, check valve; 5, EGR valve; 6, intake manifold; 7, exhaust manifold. DETAILED DESCRIPTION

[0025] It should be noted that the embodiments and features of the embodiments in the present application can be combined with each other without conflict. The technical solutions in the embodiments of the present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0026] In order for those skilled in the art to better understand the scheme of the present application, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, not all. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor should be within the scope of protection of the present application.

[0027] It should be noted that the terms "first", "second" and the like in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and do not necessarily describe a specific order or sequence. It should be understood that the data thus used can be interchanged under appropriate circumstances, so that the embodiments of the present application described herein can be implemented. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device including a series of steps or units does not necessarily limit to those steps or units clearly listed, but can include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0028] For the convenience of description, the following describes some nouns or terms related to the embodiments of the present application:

[0029] EGR system: Exhaust Gas Re-circulation, commonly known as EGR system, which returns part of the exhaust gas discharged by the engine to the intake manifold and enters the cylinder again with fresh mixture.

[0030] As introduced in the background, high temperature exhaust gas can cause EGR melting in the case of EGR cooler failure in the prior art. To solve the problem that high temperature exhaust gas can cause EGR melting, the embodiments of the present application provide a control method, control device, computer readable storage medium and electronic equipment of EGR valve.

[0031] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

[0032] The methods and embodiments provided in this application can be executed on a mobile terminal, computer terminal, or similar computing device. Taking running on a mobile terminal as an example, Figure 1 This is a hardware structure block diagram of a mobile terminal for an EGR valve control method according to an embodiment of the present invention. Figure 1 As shown, a mobile terminal may include one or more ( Figure 1 Only one is shown in the diagram. A processor 102 (which may include, but is not limited to, a microprocessor MCU or a programmable logic device FPGA, etc.) and a memory 104 for storing data are also shown. The mobile terminal may further include a transmission device 106 for communication functions and an input / output device 108. Those skilled in the art will understand that... Figure 1 The structure shown is for illustrative purposes only and does not limit the structure of the mobile terminal described above. For example, the mobile terminal may also include components that are more... Figure 1 The more or fewer components shown, or having the same Figure 1 The different configurations shown.

[0033] The memory 104 can be used to store computer programs, such as application software programs and modules, like the computer program corresponding to the EGR valve control method in this embodiment of the invention. The processor 102 executes various functional applications and data processing by running the computer program stored in the memory 104, thereby implementing the above-described method. The memory 104 may include high-speed random access memory and non-volatile memory, such as one or more magnetic storage devices, flash memory, or other non-volatile solid-state memory. In some instances, the memory 104 may further include memory remotely located relative to the processor 102, and these remote memories can be connected to the mobile terminal via a network. Examples of the aforementioned networks include, but are not limited to, the Internet, corporate intranets, local area networks, mobile communication networks, and combinations thereof. The transmission device 106 is used to receive or send data via a network. Specific examples of the aforementioned networks may include wireless networks provided by the mobile terminal's communication provider. In one example, the transmission device 106 includes a network interface controller (NIC), which can be connected to other network devices via a base station to communicate with the Internet. In one example, the transmission device 106 may be a radio frequency (RF) module, which is used to communicate with the Internet wirelessly.

[0034] A control method of an EGR valve running on a mobile terminal, a computer terminal or the like is provided in the embodiment. It should be noted that the steps shown in the flowchart of the drawings can be executed in a computer system such as a set of computer executable instructions, and although a logical sequence is shown in the flowchart, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0035] Figure 2 A flowchart of a control method of an EGR valve according to the embodiment of the application is shown in FIG. 1. The EGR valve is included in an EGR system, which further includes an EGR cooler and a check valve. The EGR cooler, the check valve and the EGR valve are connected in sequence as shown in FIG. 2. The method includes the following steps: Figure 2

[0036] In step S201, the temperature of the exhaust gas of the engine after being cooled by the EGR cooler is obtained to obtain a cooled temperature, and the current opening of the EGR valve is obtained to obtain an EGR valve current opening. The EGR system is included in the engine.

[0037] Specifically, the EGR is an exhaust gas recirculation system of the engine. The exhaust gas of the engine is introduced into the intake manifold again to be introduced into the cylinder again together with fresh mixture. This process first needs to be cooled by the EGR cooler, otherwise the high-temperature gas passing through the check valve will cause burning problem. Therefore, the cooler front temperature sensor and the cooler rear temperature sensor are usually provided on the EGR cooler. The temperatures before and after the exhaust gas of the engine passing through the EGR cooler can be measured by the corresponding sensors. The current opening of the EGR valve is also needed to be obtained to determine whether the EGR cooler fails subsequently.

[0038] In step S202, the cooling efficiency of the EGR cooler is calculated. In the case that the cooling efficiency is less than or equal to a first preset threshold, a correction factor is obtained. The product of the cooling efficiency, the correction factor and the EGR valve current opening is calculated to obtain an EGR valve target opening. In the case that the EGR valve target opening is different from the EGR valve current opening, the opening of the EGR valve is controlled to be the EGR valve target opening. The correction factor is used to correct the opening of the EGR valve. The cooling efficiency is the efficiency of the EGR cooler cooling the exhaust gas of the engine.

[0039] ​Specifically, whether the EGR cooler can cool the exhaust gas of the engine, i.e., whether the EGR cooler can work normally, is generally determined by the cooling efficiency of the EGR cooler, and therefore, the cooling efficiency of the EGR cooler is first calculated, and the first preset threshold, i.e., the EGR cooler efficiency threshold corresponding to the current speed and the oil amount, is obtained by querying the pre-calibrated MAP, that is, the efficiency threshold that the EGR cooler should reach under the current speed and the oil amount, and in the case that the calculated EGR cooling efficiency is less than or equal to the efficiency threshold, it is indicated that the efficiency of the EGR cooler does not meet the minimum requirement, and it is further indicated that the cooling efficiency of the EGR cooler is low, and the EGR cooler has a fault. In this case, a correction factor is obtained, and the correction factor is obtained by querying the pre-calibrated EGR cooling temperature, EGR exhaust flow and correction factor MAP according to the cooling temperature, the current exhaust flow, and in the case that the correction factor is obtained, the product of the above cooling efficiency, the correction factor and the current opening degree of the EGR valve is calculated to correct the current opening degree of the EGR valve, and the target opening degree of the EGR valve is obtained. The value of the correction factor is less than 1, i.e., the target opening degree of the EGR valve is reduced compared with the current opening degree of the EGR valve.

[0040] Step S203, in the case that the above cooling efficiency is greater than the above first preset threshold and the above cooling temperature is greater than or equal to the above second preset threshold, the above EGR valve is controlled to be closed.

[0041] Specifically, in the case that the cooling efficiency is normal, i.e., the cooling efficiency is greater than the first preset threshold, it is judged whether the cooling temperature is greater than or equal to the second preset threshold, and the second preset threshold is the maximum temperature threshold corresponding to the speed and the oil amount. The maximum temperature threshold is generally 20℃ lower than the limit high temperature that the EGR one-way valve can withstand. In the case that the cooling temperature after the cooler is greater than or equal to the maximum temperature threshold, it is indicated that the cooling temperature is too high, and it is further indicated that the cooler cannot cool the exhaust, and the cooler has a fault. In this case, the opening degree of the EGR valve is directly controlled to be 0, i.e., the EGR valve is closed. The smaller the cooling efficiency of the EGR cooler is, the faster the closing rate of the EGR valve is.

[0042] By the embodiment, the temperature after cooling of the EGR cooler and the current opening degree of the EGR valve in the EGR system are obtained, and the cooling efficiency of the EGR cooler is calculated. In the case that the cooling efficiency is less than a first preset threshold, the product of the cooling efficiency, the correction factor and the current opening degree of the EGR valve is calculated to obtain the target opening degree of the EGR valve. In the case that the cooling efficiency is greater than the first preset threshold and the temperature after cooling is greater than a second preset threshold, the EGR valve is controlled to be closed. In this way, by monitoring the cooling efficiency and the temperature after cooling of the EGR cooler, when the EGR cooling efficiency is low or the temperature after cooling is too high, the flow of the exhaust gas of the EGR valve can be reduced or interrupted in time, so as to avoid the EGR valve from being burned and fused due to the hot gas impact. Compared with the prior art in which the high-temperature EGR exhaust flow still flows through the EGR valve after the EGR cooler fails, which can cause the EGR valve to be burned and fused, the present application reduces or interrupts the flow of the high-temperature exhaust of the EGR valve in time, so as to avoid further burning and fusing or damage of the EGR valve, and thus the problem of the EGR valve being burned and fused due to the high-temperature exhaust in the prior art can be solved.

[0043] In the implementation process, the above step S202 can be implemented by the following steps: as shown in the figure: Figure 3 Step S2021: obtaining the temperature of the exhaust gas of the engine before being cooled by the EGR cooler to obtain the temperature before cooling; and step S2022: calculating the ratio of the temperature after cooling to the temperature before cooling, and calculating the difference between 1 and the ratio to obtain the cooling efficiency. The cooling efficiency is calculated by the temperature before cooling and the temperature after cooling, so that the cooling efficiency can be accurately calculated, and then whether the EGR cooler is faulty is determined by the cooling efficiency.

[0044] Specifically, the cooling efficiency can be calculated by (1-temperature after cooling / temperature before cooling), so that the cooling efficiency can be accurately obtained by only obtaining the temperature before cooling and calculating. The temperature before cooling and the temperature after cooling can be measured by the temperature sensors arranged at the front end and the rear end of the EGR cooler. The front end and the rear end refer to the direction of the gas flow, that is, the end flowing first is the front end, and the end flowing last is the rear end.

[0045] In order to accurately obtain the correction factor for correcting the opening degree of the EGR valve, the above step S202 can also be implemented by the following steps: obtaining a plurality of historical cooled temperatures, a plurality of historical EGR valve flows, and a historical correction factor corresponding to each of the historical cooled temperatures and the historical EGR valve flows, to obtain a one-to-one mapping relationship among the cooled temperature, the EGR valve flow, and the correction factor; obtaining a current EGR valve flow, determining a historical correction factor corresponding to the current cooled temperature and the current EGR valve flow through the one-to-one mapping relationship among the cooled temperature, the EGR valve flow, and the correction factor, to obtain the correction factor. This method calibrates the historical correction factor according to the historical cooled temperature and the historical EGR valve flow, to obtain a one-to-one mapping relationship among the parameters, so that the correction factor corresponding to the current cooled temperature and the current EGR valve flow can be determined through the one-to-one mapping relationship.

[0046] In the specific implementation process, a plurality of historical cooled temperatures, a plurality of historical EGR valve flows, and a historical correction factor corresponding to each of the parameters are obtained through experiments or simulations, to obtain a one-to-one mapping relationship among the cooled temperature, the EGR valve flow, and the correction factor. The one-to-one mapping relationship can be in the form of a MAP (i.e., a map) or a table having a one-to-one mapping relationship. After the current cooled temperature and the current EGR valve flow are obtained, the historical correction factor corresponding to the historical cooled temperature and the historical EGR valve flow that are the same as the current cooled temperature and the current EGR valve flow in the one-to-one mapping relationship can be determined as the correction factor corresponding to the current cooled temperature and the current EGR valve flow.

[0047] The above method further includes the following steps, for example: in a case where the duration during which the cooling efficiency is less than or equal to the first preset threshold is greater than or equal to a first preset time period, controlling the EGR cooler to generate an alarm signal to prompt a failure of the EGR cooler; and in a case where the duration during which the cooling efficiency is greater than the first preset threshold is greater than or equal to a second preset time period and the duration during which the cooled temperature is greater than or equal to the second preset threshold is greater than or equal to the second preset time period, controlling the EGR cooler to generate the alarm signal to prompt the failure of the EGR cooler. In a case where the cooling efficiency or the cooled temperature indicates a failure of the cooler, the method generates an alarm signal to prompt the failure of the EGR cooler, so as to prompt the driver to troubleshoot the failure, and to ensure the safety of the EGR system of the subsequent vehicle and the stability of the engine or the emission.

[0048] Specifically, in the case that the cooling efficiency is less than or equal to the first preset threshold for a duration greater than or equal to the first preset time period, or in the case that the cooling efficiency is greater than the first preset threshold for a duration greater than or equal to the second preset time period and the temperature after cooling is greater than or equal to the second preset threshold for a duration greater than or equal to the second preset time period, it indicates that the EGR cooler is malfunctioning, and thus an alarm signal is generated, i.e., an EGR cooler malfunction is reported, the engine light is on, and the driver is prompted to handle it in time.

[0049] In order to limit the torque of the engine in the case of EGR cooler malfunction and avoid causing engine malfunction, in some embodiments, the method can further include the steps of: obtaining the current torque of the engine, wherein the EGR system is included in the engine; in the case that the cooling efficiency is less than or equal to the first preset threshold, calculating the product of the cooling efficiency, the correction factor and the current torque to obtain a target torque, and controlling the engine to operate at the target torque; and in the case that the temperature after cooling is greater than or equal to the second preset threshold, controlling the engine speed to be idle. The method further corrects the engine torque by the correction factor, so that in the case of EGR cooler malfunction, the EGR opening is limited while the EGR torque is limited, avoiding the malfunction of the EGR valve and the engine.

[0050] In the specific implementation process, the torque of the engine is simultaneously limited while the opening of the EGR valve is controlled to decrease to the target opening or be closed. The same as the correction method of the opening of the EGR valve, in the case that the cooling efficiency is less than or equal to the first preset threshold, i.e., the cooling efficiency is lower than the efficiency threshold, the product of the cooling efficiency, the correction factor and the current torque is calculated to correct the current torque and obtain a target torque, and the engine is controlled to operate at the target torque. In the case that the temperature after cooling is greater than or equal to the second preset threshold, i.e., the temperature after cooling is higher than the maximum temperature threshold, the product of the correction factor and the current torque is calculated to obtain a target torque, i.e., the target torque is 0, the torque of the engine is controlled to be 0, or the engine speed is controlled to be idle, i.e., the engine operates in neutral.

[0051] In some optional embodiments, the control method further comprises the following steps: obtaining a current speed and a current oil amount of the engine; determining a cooling efficiency threshold corresponding to the current speed and the current oil amount through a one-to-one mapping relationship between the speed, the oil amount, and the cooling efficiency threshold, to obtain the first preset threshold, wherein the one-to-one mapping relationship between the speed, the oil amount, and the cooling efficiency threshold comprises a plurality of historical speeds and the historical oil amount and the historical cooling efficiency threshold corresponding to each of the historical speeds; and determining a temperature threshold corresponding to the current speed and the current oil amount through a one-to-one mapping relationship between the speed, the oil amount, and the cooled temperature threshold, to obtain the second preset threshold, wherein the one-to-one mapping relationship between the speed, the oil amount, and the cooled temperature threshold comprises a plurality of historical speeds and the historical oil amount and the historical temperature threshold corresponding to each of the historical speeds. The method determines the first preset threshold through the one-to-one mapping relationship between the speed, the oil amount, and the cooling efficiency threshold, and determines the second preset threshold through the one-to-one mapping relationship between the speed, the oil amount, and the cooled temperature threshold, so that the first preset threshold and the second preset threshold can be accurately determined.

[0052] Specifically, the current speed and the current oil amount of the engine are obtained, the historical cooling efficiency threshold corresponding to the historical speed and the historical oil amount same as the current speed and the current oil amount in the one-to-one mapping relationship between the speed, the oil amount, and the cooling efficiency threshold is taken as the first preset threshold, and the historical temperature threshold corresponding to the historical speed and the historical oil amount same as the current speed and the current oil amount in the one-to-one mapping relationship between the speed, the oil amount, and the cooled temperature threshold is taken as the second preset threshold.

[0053] To make the calculation of the EGR cooling efficiency more accurate, the step S201 can be implemented through the following steps: obtaining the gas temperature of the exhaust gas of the engine after the exhaust gas is cooled by the EGR cooler to obtain the cooled temperature, in the case that the current opening degree of the EGR valve is greater than or equal to 0 and the engine in which the EGR system is located has no error. The method obtains the cooled temperature and performs subsequent judgment only under the above conditions, so that the calculation of the cooling efficiency is performed under the above conditions, so as to more accurately calculate the EGR cooling efficiency.

[0054] In the specific implementation process, the calculation of the EGR cooler cooling efficiency and the obtaining of the cooled temperature are further performed only under the conditions that the engine is running and has no related faults, and the EGR rate or the EGR opening degree is greater than or equal to 0. If the above conditions are not met, for example, the engine is not in a running state, it is not necessary to determine whether the EGR cooler is faulty, or in the case that the engine has reported a fault, it is not necessary to determine the EGR cooling efficiency and whether a fault occurs.

[0055] In order to enable those skilled in the art to more clearly understand the technical solutions of the present application, the implementation process of the EGR valve control method of the present application will be described in detail below in conjunction with specific embodiments.

[0056] The present embodiment relates to a specific EGR valve control method, Figure 4 The present embodiment relates to a specific EGR valve control method, Figure 5 The present embodiment relates to a specific EGR valve control method,

[0057] Step S1: When the engine is running and there is no fault, and the EGR rate or EGR opening (current opening of the EGR valve) is greater than or equal to 0, proceed to the next step.

[0058] Step S2: Obtain the normal EGR cooler rear temperature (cooled rear temperature) and the normal EGR cooler front temperature (cooler front temperature), calculate the cooling efficiency of the EGR cooler = (1-normal EGR cooler rear temperature ÷ normal EGR cooler front temperature), determine the EGR cooler efficiency threshold value (first preset threshold value) corresponding to the current speed and oil amount according to the speed, oil amount and EGR cooler efficiency threshold value MAP, in the case of EGR cooler efficiency threshold value ≤ EGR cooler efficiency threshold value, after the above state passes through the delay time, then the EGR cooler efficiency is low and an error is reported (alarm signal), " / 1 / " represents that the "EGR cooler efficiency is low and an error is reported" satisfies the enabling condition, in the case of EGR cooler efficiency threshold value > EGR cooler efficiency threshold value, the "EGR cooler efficiency is low and an error is reported" does not satisfy the enabling condition, the speed, oil amount and EGR cooler efficiency threshold value MAP are pre-labeled through experimental data such as speed, oil amount and EGR cooler efficiency threshold value;

[0059] Step S3: In the case that the EGR cooler efficiency > EGR cooler efficiency threshold value (first preset threshold value), i.e., the EGR cooler efficiency does not satisfy the enabling condition of "EGR cooler efficiency is low and an error is reported", further determine the maximum temperature threshold value (second preset threshold value) corresponding to the current speed and oil amount according to the speed, oil amount and maximum temperature threshold value MAP, determine whether the normal EGR cooler rear temperature is greater than or equal to the maximum temperature threshold value (second preset threshold value), in the case of normal EGR cooler rear temperature ≥ maximum temperature threshold value, after passing through the delay time, the enabling condition of "EGR cooler efficiency is low and an error is reported" is satisfied, then the EGR cooler efficiency is low and an error is reported (alarm signal);

[0060] Step S4: determining the correction factor corresponding to the current EGR cooler rear temperature and the EGR exhaust gas amount according to the EGR cooler rear temperature, the EGR exhaust gas flow and the correction factor MAP, multiplying the correction factor, the EGR cooling efficiency and the EGR opening degree to obtain the EGR opening degree (EGR valve target opening degree) under the condition that the EGR cooler efficiency threshold value ≤ the EGR cooler efficiency threshold value is met, and controlling the EGR valve to be the EGR opening degree (EGR valve target opening degree), and multiplying the correction factor, the EGR cooling efficiency and the engine torque to obtain the engine torque (target torque), and controlling the engine to operate at the target torque;

[0061] Step S5: multiplying 0, the correction factor and the EGR opening degree to obtain the EGR opening degree, i.e. the EGR valve target opening degree is 0, and the EGR valve is closed under the condition that the normal EGR cooler rear temperature ≥ the maximum temperature threshold value is met;

[0062] Step S6: multiplying the correction factor, the EGR cooling efficiency and the EGR opening degree to obtain the EGR opening degree (EGR valve target opening degree) under the condition that both of the above two conditions are met, i.e. the EGR cooler efficiency threshold value ≤ the EGR cooler efficiency threshold value and the normal EGR cooler rear temperature ≥ the maximum temperature threshold value, and controlling the EGR valve to be the EGR opening degree (EGR valve target opening degree), and multiplying 0, the correction factor and the engine torque to obtain the engine torque as 0, i.e. controlling the engine torque as 0.

[0063] The embodiment of the present application also provides an EGR valve control device. It should be noted that the EGR valve control device of the embodiment of the present application can be used to execute the control method for the EGR valve provided by the embodiment of the present application. The device is used to realize the above-mentioned embodiment and preferred embodiment, and the description is not repeated. As used below, the term "module" can be a combination of software and / or hardware that realizes a predetermined function. Although the device described in the following embodiment is preferably realized in software, the realization of hardware, or a combination of software and hardware, is also possible and conceived.

[0064] The EGR valve control device provided by the embodiment of the present application is described below.

[0065] Figure 6 is a schematic diagram of the EGR valve control device according to the embodiment of the present application. The above-mentioned EGR valve is included in an EGR system, and the above-mentioned EGR system further includes an EGR cooler and a one-way valve, and the above-mentioned EGR cooler, one-way valve and EGR valve are connected in sequence, as shown in Figure 6 the device includes:

[0066] The first acquisition unit 10 is configured to acquire the temperature of the exhaust gas of the engine after the exhaust gas is cooled by the EGR cooler to obtain a cooled temperature, and acquire a current opening degree of the EGR valve to obtain an EGR valve current opening degree, wherein the EGR system is included in the engine;

[0067] Specifically, the EGR is an exhaust gas recirculation system of the engine, and the exhaust gas of the engine is introduced into the intake manifold again to be introduced into the cylinder again together with fresh mixture. This process first needs to be cooled by the EGR cooler, otherwise the high-temperature gas will cause burning problems after passing through the one-way valve. Therefore, the EGR cooler is usually provided with a cooler front temperature sensor and a cooler rear temperature sensor. The temperatures of the exhaust gas of the engine before and after the exhaust gas is cooled by the EGR cooler can be measured by the corresponding sensors. In addition, the current opening degree of the EGR valve needs to be acquired so as to subsequently judge whether the EGR cooler fails.

[0068] The first control unit 20 is configured to calculate a cooling efficiency of the EGR cooler, acquire a correction factor in a case where the cooling efficiency is less than or equal to a first preset threshold, calculate a product of the cooling efficiency, the correction factor and the EGR valve current opening degree to obtain an EGR valve target opening degree, and control the opening degree of the EGR valve to be the EGR valve target opening degree in a case where the EGR valve target opening degree is different from the EGR valve current opening degree, wherein the correction factor is used to correct the opening degree of the EGR valve, and the cooling efficiency is an efficiency of the EGR cooler cooling the exhaust gas of the engine;

[0069] Specifically, whether the EGR cooler can cool the exhaust gas of the engine, that is, whether the EGR cooler can work normally, is determined by the cooling efficiency of the EGR cooler. Therefore, the cooling efficiency of the EGR cooler is first calculated. The first preset threshold is an EGR cooler efficiency threshold corresponding to the current speed and the oil amount, which is obtained by querying a pre-labeled MAP. That is, the efficiency threshold that the EGR cooler should reach under the current speed and the oil amount. In a case where the calculated EGR cooling efficiency is less than or equal to the efficiency threshold, it is indicated that the efficiency of the EGR cooler does not meet the minimum requirement, and it is further indicated that the cooling efficiency of the EGR cooler is low, and the EGR cooler fails. In this case, the correction factor is acquired. The correction factor is obtained by querying a pre-labeled EGR cooled temperature, EGR exhaust gas flow and correction factor MAP according to the cooled temperature and the current exhaust gas flow. After the correction factor is obtained, the current opening degree of the EGR valve is corrected by calculating the product of the cooling efficiency, the correction factor and the EGR valve current opening degree to obtain the EGR valve target opening degree. The value of the correction factor is less than 1, that is, the EGR valve target opening degree is reduced compared with the EGR valve current opening degree.

[0070] The second control unit 30 is configured to control the EGR valve to be closed when the cooling efficiency is greater than the first preset threshold and the temperature after cooling is greater than or equal to the second preset threshold.

[0071] Specifically, when the cooling efficiency is normal, i.e., the cooling efficiency is greater than the first preset threshold, it is determined whether the temperature after cooling is greater than or equal to the second preset threshold, which is the maximum temperature threshold corresponding to the speed and the oil amount. The maximum temperature threshold is generally 20℃ lower than the maximum high temperature that the EGR check valve can withstand. When the temperature after cooling of the cooler is greater than or equal to the maximum temperature threshold, it indicates that the temperature after cooling is too high, and further indicates that the cooler cannot cool the exhaust gas, and the cooler is malfunctioning. In this case, the opening of the EGR valve is directly controlled to be 0, i.e., the EGR valve is closed. The smaller the cooling efficiency of the EGR cooler, the faster the closing rate of the EGR valve.

[0072] According to the embodiment, the temperature after cooling of the EGR cooler and the current opening of the EGR valve in the EGR system are obtained, and the cooling efficiency of the EGR cooler is calculated. When the cooling efficiency is less than the first preset threshold, the product of the cooling efficiency, the correction factor and the current opening of the EGR valve is calculated to obtain the target opening of the EGR valve. When the cooling efficiency is greater than the first preset threshold and the temperature after cooling is greater than the second preset threshold, the EGR valve is controlled to be closed. In this way, by monitoring the cooling efficiency and the temperature after cooling of the EGR cooler, when the cooling efficiency of the EGR cooler is low or the temperature after cooling is too high, the flow of the exhaust gas of the EGR valve can be reduced or interrupted in time, so as to avoid the EGR valve from being burned and melted due to the impact of hot gas. Compared with the prior art, in which the flow of high-temperature exhaust gas of the EGR cooler still passes through the EGR valve after the EGR cooler fails, which can cause the EGR valve to be burned and melted, the present application reduces or interrupts the flow of high-temperature exhaust gas of the EGR valve in time, so as to avoid further burning and melting or damage of the EGR valve, and thus the problem of the EGR valve being burned and melted caused by high-temperature exhaust gas in the prior art can be solved.

[0073] In a specific implementation process, the first control unit includes a first acquisition module and a first calculation module. The first acquisition module is configured to obtain the temperature of the exhaust gas of the engine before being cooled by the EGR cooler to obtain the temperature before cooling. The first calculation module is configured to calculate the ratio of the temperature after cooling to the temperature before cooling, and calculate the difference between 1 and the ratio to obtain the cooling efficiency. This method calculates the cooling efficiency by the temperature before cooling and the temperature after cooling, so that the cooling efficiency can be accurately calculated, and then it is determined whether the EGR cooler is malfunctioning by the cooling efficiency.

[0074] Specifically, the cooling efficiency can be calculated by (1-cooling after temperature / cooling before temperature), so that only the cooling before temperature needs to be obtained and the cooling efficiency can be accurately obtained by calculation. The cooling before temperature and the cooling after temperature can be measured by temperature sensors arranged at the front end and the rear end of the EGR cooler. The front end and the rear end refer to the direction of the gas flow, the end flowing first is the front end, and the end flowing last is the rear end.

[0075] In order to accurately obtain the correction factor to correct the opening of the EGR valve, the first control unit further comprises a second obtaining module and a determining module. The second obtaining module is configured to obtain a plurality of historical cooling after temperatures, a plurality of historical EGR valve flow rates, and a historical correction factor corresponding to each of the historical cooling after temperatures and each of the historical EGR valve flow rates, to obtain a one-to-one mapping relationship among the cooling after temperature, the EGR valve flow rate, and the correction factor. The determining module is configured to obtain a current EGR valve flow rate, determine a historical correction factor corresponding to the cooling after temperature and the current EGR valve flow rate through the one-to-one mapping relationship among the cooling after temperature, the EGR valve flow rate, and the correction factor, and obtain the correction factor. This method calibrates the historical correction factor according to the historical cooling after temperature and the historical EGR valve flow rate, to obtain a one-to-one mapping relationship among the parameters. Thus, the correction factor corresponding to the current cooling after temperature and the current EGR valve flow rate can be determined through the one-to-one mapping relationship.

[0076] In the specific implementation process, a plurality of historical cooling after temperatures, a plurality of historical EGR valve flow rates, and a historical correction factor corresponding to each of the parameters are obtained through experiments or simulations, to obtain a one-to-one mapping relationship among the cooling after temperature, the EGR valve flow rate, and the correction factor. The one-to-one mapping relationship can be in the form of a MAP (map) or a table with a one-to-one mapping relationship. After the cooling after temperature and the current EGR valve flow rate are obtained, the historical correction factor corresponding to the historical cooling after temperature and the historical EGR valve flow rate in the one-to-one mapping relationship can be determined as the correction factor corresponding to the cooling after temperature and the current EGR valve flow rate.

[0077] The method further comprises a third control unit and a fourth control unit. The third control unit is configured to control the EGR cooler to generate an alarm signal to indicate a failure of the EGR cooler when the cooling efficiency is less than or equal to the first preset threshold for a duration greater than or equal to the first preset time period. The fourth control unit is configured to control the EGR cooler to generate the alarm signal to indicate the failure of the EGR cooler when the cooling efficiency is greater than the first preset threshold for a duration greater than or equal to the second preset time period and the temperature after cooling is greater than or equal to the second preset threshold for a duration greater than or equal to the second preset time period. In the case where the cooling efficiency or the temperature after cooling indicates a failure of the cooler, the alarm signal is generated to indicate the failure of the EGR cooler, so as to prompt the driver to troubleshoot the failure and ensure the safety of the EGR system of the subsequent vehicle and the stability of the engine or emission.

[0078] Specifically, in the case where the cooling efficiency is less than or equal to the first preset threshold for a duration greater than or equal to the first preset time period or in the case where the cooling efficiency is greater than the first preset threshold for a duration greater than or equal to the second preset time period and the temperature after cooling is greater than or equal to the second preset threshold for a duration greater than or equal to the second preset time period, the EGR cooler is indicated to fail, and thus the alarm signal is generated, i.e., the EGR cooler failure is reported, and the engine is lighted to prompt the driver to timely handle.

[0079] In order to limit the torque of the engine in the case where the EGR cooler fails and avoid causing the failure of the engine, in some embodiments, the device further comprises a second acquisition unit, a fifth control unit and a sixth control unit. The current torque of the engine is acquired, and the second acquisition unit is configured to acquire the EGR system in the engine. The fifth control unit is configured to calculate a product of the cooling efficiency, the correction factor and the current torque to obtain a target torque when the cooling efficiency is less than or equal to the first preset threshold, and control the engine to operate at the target torque. The sixth control unit is configured to control the engine to rotate at an idle speed when the temperature after cooling is greater than or equal to the second preset threshold. The method further corrects the torque of the engine through the correction factor, so as to limit the EGR opening and the EGR torque in the case where the EGR cooler fails, and avoid causing the failure of the EGR valve and the engine.

[0080] In the specific implementation process, while the opening of the EGR valve is controlled to decrease to the target opening or to be closed, the torque of the engine is simultaneously limited. The same as the above-mentioned correction method of the opening of the EGR valve, in the case that the cooling efficiency is less than or equal to the first preset threshold, i.e., the cooling efficiency is lower than the efficiency threshold, the product of the cooling efficiency, the correction factor and the current torque is calculated, the current torque is corrected to obtain the target torque, and the engine is controlled to operate at the target torque; in the case that the temperature after cooling is greater than or equal to the second preset threshold, i.e., the temperature after cooling is higher than the maximum temperature threshold, the product of 0, the correction factor and the current torque is calculated to obtain the target torque, i.e., the target torque is 0, the torque of the engine is controlled to be 0, or the speed of the engine is controlled to be the idle speed, i.e., the engine operates in the neutral gear.

[0081] In some optional embodiments, the control method further comprises a third acquisition unit, a first determination unit and a second determination unit. The third acquisition unit is configured to acquire the current speed and the current oil amount of the engine. The first determination unit is configured to determine the cooling efficiency threshold corresponding to the current speed and the current oil amount according to a one-to-one mapping relationship among the speed, the oil amount and the cooling efficiency threshold, to obtain the first preset threshold. The one-to-one mapping relationship among the speed, the oil amount and the cooling efficiency threshold comprises a plurality of historical speeds, and the historical cooling efficiency threshold corresponding to each of the historical speeds and the historical oil amount. The second determination unit is configured to determine the temperature threshold corresponding to the current speed and the current oil amount according to a one-to-one mapping relationship among the speed, the oil amount and the temperature threshold after cooling, to obtain the second preset threshold. The one-to-one mapping relationship among the speed, the oil amount and the temperature threshold after cooling comprises a plurality of historical speeds, and the historical temperature threshold corresponding to each of the historical speeds and the historical oil amount. The first preset threshold is determined according to the one-to-one mapping relationship among the speed, the oil amount and the cooling efficiency threshold, and the second preset threshold is determined according to the one-to-one mapping relationship among the speed, the oil amount and the temperature threshold after cooling, so that the first preset threshold and the second preset threshold can be accurately determined.

[0082] Specifically, the current speed and the current oil amount of the engine are acquired, the historical cooling efficiency threshold corresponding to the historical speed and the historical oil amount same as the current speed and the current oil amount in the one-to-one mapping relationship among the speed, the oil amount and the cooling efficiency threshold is taken as the first preset threshold, and the historical temperature threshold corresponding to the historical speed and the historical oil amount same as the current speed and the current oil amount in the one-to-one mapping relationship among the speed, the oil amount and the temperature threshold after cooling is taken as the second preset threshold.

[0083] In order to make the calculation of the above-mentioned EGR cooling efficiency more accurate, the above-mentioned first acquisition unit comprises a third acquisition module, configured to acquire the gas temperature of the exhaust gas of the engine after being cooled by the EGR cooler under the condition that the current opening degree of the EGR valve is greater than or equal to 0 and the engine in which the EGR system is located has no error, and obtain the cooled temperature. The method acquires the cooled temperature and performs subsequent judgment only under the above-mentioned condition, so that the calculation of the cooling efficiency is performed under the above-mentioned condition, so as to more accurately calculate the EGR cooling efficiency.

[0084] In the specific implementation process, the calculation of the EGR cooler cooling efficiency and the acquisition of the cooled temperature are further performed only under the condition that the engine is running and has no related fault and the EGR rate or the EGR opening degree is greater than or equal to 0, and if the above-mentioned condition is not met, for example, the engine is not in a running state, it is not necessary to determine whether the EGR cooler is faulty, or in the case that the engine has reported a fault, it is also not necessary to determine the EGR cooling efficiency and whether the fault occurs.

[0085] The control device of the above-mentioned EGR valve comprises a processor and a memory, and the above-mentioned first acquisition unit, the first control unit and the second control unit are all stored in the memory as program units, and the corresponding functions are realized by the processor executing the above-mentioned program units stored in the memory. The above-mentioned modules are all located in the same processor, or the above-mentioned modules are respectively located in different processors in any combination.

[0086] The processor comprises a core, and the core retrieves the corresponding program unit from the memory. The core can be one or more, and the problem of EGR valve burning can be solved by adjusting the core parameters.

[0087] The memory can include a non-permanent memory in a computer readable medium, a random access memory (RAM) and / or a non-volatile memory such as a read-only memory (ROM) or a flash memory (flash RAM), and the memory comprises at least one memory chip.

[0088] The embodiment of the application provides a computer readable storage medium, and the computer readable storage medium comprises a stored program, wherein the computer readable storage medium controls a device in which the computer readable storage medium is located to execute the control method of the EGR valve when the program runs.

[0089] Specifically, the control method of the EGR valve comprises:

[0090] In step S201, the gas temperature of the exhaust gas of the engine after being cooled by the EGR cooler is acquired to obtain the cooled temperature, and the current opening degree of the EGR valve is acquired to obtain the current opening degree of the EGR valve, wherein the EGR system is included in the engine.

[0091] Specifically, the EGR is an exhaust gas recirculation system of the engine, which introduces the exhaust gas of the engine into the intake manifold again, and introduces it into the cylinder again with fresh mixture. This process first needs to be cooled by the EGR cooler, otherwise the high-temperature gas will cause burning problems after passing through the one-way valve. Therefore, a cooler front temperature sensor and a cooler rear temperature sensor are usually arranged on the EGR cooler, and the temperatures before and after the exhaust gas of the engine passes through the EGR cooler can be measured by the corresponding sensors. The current opening of the EGR valve also needs to be obtained, so as to subsequently judge whether the EGR cooler has failed.

[0092] In step S202, the cooling efficiency of the EGR cooler is calculated. In the case where the cooling efficiency is less than or equal to a first preset threshold, a correction factor is obtained, the product of the cooling efficiency, the correction factor and the current opening of the EGR valve is calculated to obtain an EGR valve target opening, and in the case where the EGR valve target opening is different from the current opening of the EGR valve, the opening of the EGR valve is controlled to be the EGR valve target opening. The correction factor is used to correct the opening of the EGR valve, and the cooling efficiency is the efficiency of the EGR cooler cooling the exhaust gas of the engine.

[0093] Specifically, whether the EGR cooler can cool the exhaust gas of the engine, that is, whether the EGR cooler can work normally, is usually determined by the cooling efficiency of the EGR cooler. Therefore, the cooling efficiency of the EGR cooler is first calculated. The first preset threshold is the EGR cooler efficiency threshold corresponding to the current speed and oil quantity, which is obtained by querying the pre-calibrated MAP. That is, under the current speed and oil quantity, the efficiency threshold that the EGR cooler should reach. In the case where the calculated EGR cooling efficiency is less than or equal to the efficiency threshold, it indicates that the efficiency of the EGR cooler does not meet the minimum requirement, and further indicates that the cooling efficiency of the EGR cooler is low, and the EGR cooler has failed. In this case, a correction factor is obtained. The correction factor is obtained by querying the pre-calibrated EGR cooling temperature, EGR exhaust gas flow and correction factor MAP according to the cooling temperature and the current exhaust gas flow. After obtaining the correction factor, the current opening of the EGR valve is corrected by calculating the product of the cooling efficiency, the correction factor and the current opening of the EGR valve to obtain the EGR valve target opening. The value of the correction factor is less than 1, that is, the EGR valve target opening is reduced compared with the current opening of the EGR valve.

[0094] In step S203, in the case where the cooling efficiency is greater than the first preset threshold and the cooling temperature is greater than or equal to the second preset threshold, the EGR valve is controlled to be closed.

[0095] Specifically, in the case that the cooling efficiency is normal, i.e., the cooling efficiency is greater than a first preset threshold, it is determined whether the temperature after cooling is greater than or equal to a second preset threshold, the second preset threshold being a maximum temperature threshold corresponding to the rotation speed and the oil amount, and the maximum temperature threshold generally being 20℃ less than the limit high temperature that the EGR one-way valve can withstand. In the case that the temperature after cooling of the cooler is greater than or equal to the maximum temperature threshold, it is indicated that the temperature after cooling is too high, and it is further indicated that the cooler cannot cool the exhaust gas, and the cooler is malfunctioning. In this case, the opening of the EGR valve is directly controlled to be 0, i.e., the EGR valve is closed. The smaller the cooling efficiency of the EGR cooler, the faster the closing rate of the EGR valve.

[0096] Optionally, the cooling efficiency of the EGR cooler is calculated, including: obtaining a temperature of the exhaust gas of the engine before the exhaust gas is cooled by the EGR cooler, to obtain a temperature before cooling; calculating a ratio of the temperature after cooling to the temperature before cooling, and calculating a difference between 1 and the ratio, to obtain the cooling efficiency.

[0097] Optionally, the correction factor is obtained, including: obtaining a plurality of historical temperatures after cooling, a plurality of historical EGR valve flow rates, and a historical correction factor corresponding to each of the historical temperatures after cooling and each of the historical EGR valve flow rates, to obtain a one-to-one mapping relationship among the temperature after cooling, the EGR valve flow rate, and the correction factor; obtaining a current EGR valve flow rate, and determining a historical correction factor corresponding to the temperature after cooling and the current EGR valve flow rate through the one-to-one mapping relationship among the temperature after cooling, the EGR valve flow rate, and the correction factor, to obtain the correction factor.

[0098] Optionally, in the case that the cooling efficiency is less than or equal to the first preset threshold or in the case that the cooling efficiency is greater than the first preset threshold and the temperature after cooling is greater than or equal to the second preset threshold, the control method further includes: in the case that a duration in which the cooling efficiency is less than or equal to the first preset threshold is greater than or equal to a first preset time period, controlling the EGR cooler to generate an alarm signal to prompt that the EGR cooler is malfunctioning; and in the case that a duration in which the cooling efficiency is greater than the first preset threshold is greater than or equal to a second preset time period and a duration in which the temperature after cooling is greater than or equal to the second preset threshold is greater than or equal to the second preset time period, controlling the EGR cooler to generate the alarm signal to prompt that the EGR cooler is malfunctioning.

[0099] Optionally, the control method further comprises: obtaining a current torque of the engine, wherein the EGR system is included in the engine; in a case where the cooling efficiency is less than or equal to the first preset threshold, calculating a product of the cooling efficiency, the correction factor and the current torque to obtain a target torque, and controlling the engine to operate at the target torque; and in a case where the post-cooling temperature is greater than or equal to the second preset threshold, controlling a rotation speed of the engine to be an idle speed.

[0100] Optionally, the control method further comprises: obtaining a current rotation speed and a current oil amount of the engine; determining a cooling efficiency threshold corresponding to the current rotation speed and the current oil amount through a one-to-one mapping relationship between rotation speed, oil amount and cooling efficiency threshold to obtain the first preset threshold, wherein the one-to-one mapping relationship between rotation speed, oil amount and cooling efficiency threshold comprises a plurality of historical rotation speeds and a historical oil amount and a historical cooling efficiency threshold corresponding to each of the historical rotation speeds; and determining a post-cooling temperature threshold corresponding to the current rotation speed and the current oil amount through a one-to-one mapping relationship between rotation speed, oil amount and post-cooling temperature threshold to obtain the second preset threshold, wherein the one-to-one mapping relationship between rotation speed, oil amount and post-cooling temperature threshold comprises a plurality of historical rotation speeds and a historical oil amount and a historical post-cooling temperature threshold corresponding to each of the historical rotation speeds.

[0101] Optionally, the obtaining of the post-cooling temperature of the exhaust gas of the engine after being cooled by the EGR cooler comprises: in a case where the current opening degree of the EGR valve is greater than or equal to 0 and the engine in which the EGR system is located has no error, obtaining the post-cooling temperature of the exhaust gas of the engine after being cooled by the EGR cooler.

[0102] An embodiment of the present application provides a device, which comprises a processor, a memory and a program stored in the memory and capable of running on the processor, and the processor implements at least the following steps when executing the program:

[0103] In step S201, the post-cooling temperature of the exhaust gas of the engine after being cooled by the EGR cooler is obtained, and the current opening degree of the EGR valve is obtained, wherein the EGR system is included in the engine.

[0104] In step S202, the cooling efficiency of the EGR cooler is calculated. If the cooling efficiency is less than or equal to a first preset threshold, a correction factor is obtained, the product of the cooling efficiency, the correction factor and the current opening degree of the EGR valve is calculated to obtain a target opening degree of the EGR valve, and if the target opening degree of the EGR valve is different from the current opening degree of the EGR valve, the opening degree of the EGR valve is controlled to be the target opening degree of the EGR valve, wherein the correction factor is used to correct the opening degree of the EGR valve, and the cooling efficiency is the efficiency of the EGR cooler cooling the exhaust gas of the engine.

[0105] In step S203, if the cooling efficiency is greater than the first preset threshold and the cooled temperature is greater than or equal to a second preset threshold, the EGR valve is controlled to be closed.

[0106] The device herein can be a server, a PC, a PAD, a mobile phone, etc.

[0107] Optionally, the cooling efficiency of the EGR cooler is calculated by obtaining the temperature of the exhaust gas of the engine before being cooled by the EGR cooler to obtain a pre-cooling temperature, calculating the ratio of the cooled temperature to the pre-cooling temperature, and calculating the difference between 1 and the ratio to obtain the cooling efficiency.

[0108] Optionally, the correction factor is obtained by obtaining a plurality of historical cooled temperatures, a plurality of historical EGR valve flow rates and a historical correction factor corresponding to each of the historical cooled temperatures and each of the historical EGR valve flow rates to obtain a one-to-one mapping relationship among the cooled temperature, the EGR valve flow rate and the correction factor, obtaining a current EGR valve flow rate, determining the historical correction factor corresponding to the cooled temperature and the current EGR valve flow rate through the one-to-one mapping relationship among the cooled temperature, the EGR valve flow rate and the correction factor, and obtaining the correction factor.

[0109] Optionally, in the case that the cooling efficiency is less than or equal to the first preset threshold or in the case that the cooling efficiency is greater than the first preset threshold and the cooled temperature is greater than or equal to the second preset threshold, the control method further comprises: if the duration that the cooling efficiency is less than or equal to the first preset threshold is greater than or equal to a first preset time period, controlling the EGR cooler to generate an alarm signal to prompt that the EGR cooler is faulty; and if the duration that the cooling efficiency is greater than the first preset threshold is greater than or equal to a second preset time period and the duration that the cooled temperature is greater than or equal to the second preset threshold is greater than or equal to the second preset time period, controlling the EGR cooler to generate the alarm signal to prompt that the EGR cooler is faulty.

[0110] Optionally, the control method further comprises: obtaining a current torque of the engine, wherein the EGR system is included in the engine; in a case where the cooling efficiency is less than or equal to the first preset threshold, calculating a product of the cooling efficiency, the correction factor and the current torque to obtain a target torque, and controlling the engine to operate at the target torque; and in a case where the post-cooling temperature is greater than or equal to the second preset threshold, controlling a rotation speed of the engine to be an idle speed.

[0111] Optionally, the control method further comprises: obtaining a current rotation speed and a current oil amount of the engine; determining a cooling efficiency threshold corresponding to the current rotation speed and the current oil amount through a one-to-one mapping relationship between rotation speed, oil amount and cooling efficiency threshold to obtain the first preset threshold, wherein the one-to-one mapping relationship between rotation speed, oil amount and cooling efficiency threshold comprises a plurality of historical rotation speeds and, for each historical rotation speed, a historical oil amount corresponding to the historical rotation speed and a historical cooling efficiency threshold; and determining a post-cooling temperature threshold corresponding to the current rotation speed and the current oil amount through a one-to-one mapping relationship between rotation speed, oil amount and post-cooling temperature threshold to obtain the second preset threshold, wherein the one-to-one mapping relationship between rotation speed, oil amount and post-cooling temperature threshold comprises a plurality of historical rotation speeds and, for each historical rotation speed, a historical oil amount corresponding to the historical rotation speed and a historical post-cooling temperature threshold.

[0112] Optionally, the obtaining of the post-cooling temperature comprises: in a case where the current opening degree of the EGR valve is greater than or equal to 0 and the engine in which the EGR system is located has no error, obtaining the gas temperature after the exhaust gas of the engine is cooled by the EGR cooler to obtain the post-cooling temperature.

[0113] The application further provides a computer program product adapted to execute a program comprising at least the following method steps when executed on a data processing device:

[0114] In step S201, the gas temperature after the exhaust gas of the engine is cooled by the EGR cooler is obtained to obtain a post-cooling temperature, and the current opening degree of the EGR valve is obtained to obtain an EGR valve current opening degree, wherein the EGR system is included in the engine.

[0115] In step S202, the cooling efficiency of the EGR cooler is calculated. If the cooling efficiency is less than or equal to a first preset threshold, a correction factor is obtained, the product of the cooling efficiency, the correction factor and the current opening degree of the EGR valve is calculated to obtain a target opening degree of the EGR valve, and if the target opening degree of the EGR valve is different from the current opening degree of the EGR valve, the opening degree of the EGR valve is controlled to be the target opening degree of the EGR valve, wherein the correction factor is used to correct the opening degree of the EGR valve, and the cooling efficiency is the efficiency of the EGR cooler cooling the exhaust gas of the engine.

[0116] In step S203, if the cooling efficiency is greater than the first preset threshold and the cooled temperature is greater than or equal to a second preset threshold, the EGR valve is controlled to be closed.

[0117] Optionally, the cooling efficiency of the EGR cooler is calculated by obtaining the gas temperature of the exhaust gas of the engine before being cooled by the EGR cooler to obtain a pre-cooling temperature, calculating the ratio of the cooled temperature to the pre-cooling temperature, and calculating the difference between 1 and the ratio to obtain the cooling efficiency.

[0118] Optionally, the correction factor is obtained by obtaining a plurality of historical cooled temperatures, a plurality of historical EGR valve flow rates and a historical correction factor corresponding to each of the historical cooled temperatures and each of the historical EGR valve flow rates to obtain a one-to-one mapping relationship among the cooled temperature, the EGR valve flow rate and the correction factor, obtaining a current EGR valve flow rate, and determining the historical correction factor corresponding to the cooled temperature and the current EGR valve flow rate through the one-to-one mapping relationship among the cooled temperature, the EGR valve flow rate and the correction factor to obtain the correction factor.

[0119] Optionally, in the case that the cooling efficiency is less than or equal to the first preset threshold or in the case that the cooling efficiency is greater than the first preset threshold and the cooled temperature is greater than or equal to the second preset threshold, the control method further comprises: if the duration that the cooling efficiency is less than or equal to the first preset threshold is greater than or equal to a first preset time period, controlling the EGR cooler to generate an alarm signal to prompt that the EGR cooler is faulty; and if the duration that the cooling efficiency is greater than the first preset threshold is greater than or equal to a second preset time period and the duration that the cooled temperature is greater than or equal to the second preset threshold is greater than or equal to the second preset time period, controlling the EGR cooler to generate the alarm signal to prompt that the EGR cooler is faulty.

[0120] Optionally, the control method further comprises: obtaining a current torque of the engine, wherein the EGR system is included in the engine; in the case that the cooling efficiency is less than or equal to the first preset threshold, calculating a product of the cooling efficiency, the correction factor and the current torque to obtain a target torque, and controlling the engine to operate at the target torque; in the case that the post-cooling temperature is greater than or equal to the second preset threshold, controlling a rotation speed of the engine to be an idle speed.

[0121] Optionally, the control method further comprises: obtaining a current rotation speed and a current oil amount of the engine; determining a cooling efficiency threshold corresponding to the current rotation speed and the current oil amount through a one-to-one mapping relationship of rotation speed, oil amount and cooling efficiency threshold to obtain the first preset threshold, wherein the one-to-one mapping relationship of rotation speed, oil amount and cooling efficiency threshold comprises a plurality of historical rotation speeds and the historical oil amount and the historical cooling efficiency threshold corresponding to each of the historical rotation speeds; determining a post-cooling temperature threshold corresponding to the current rotation speed and the current oil amount through a one-to-one mapping relationship of rotation speed, oil amount and post-cooling temperature threshold to obtain the second preset threshold, wherein the one-to-one mapping relationship of rotation speed, oil amount and post-cooling temperature threshold comprises a plurality of historical rotation speeds and the historical oil amount and the historical post-cooling temperature threshold corresponding to each of the historical rotation speeds.

[0122] Optionally, the obtaining of the post-cooling temperature of the exhaust gas of the engine after being cooled by the EGR cooler comprises: in the case that the current opening degree of the EGR valve is greater than or equal to 0 and the engine in which the EGR system is located has no error, obtaining the post-cooling temperature of the exhaust gas of the engine after being cooled by the EGR cooler.

[0123] Obviously, those skilled in the art should understand that each module or each step of the present application described above can be realized by a general computing device, which can be concentrated on a single computing device or distributed on a network composed of multiple computing devices, and can be realized by program codes executable by the computing device, so that they can be stored in a storage device and executed by the computing device, and in some cases, the steps shown or described can be executed in different order, or they can be manufactured into each integrated circuit module respectively, or multiple modules or steps among them can be manufactured into a single integrated circuit module. Therefore, the present application is not limited to any specific combination of hardware and software.

[0124] Those skilled in the art will appreciate that embodiments of the application can be readily used as software, hardware, or a combination of software and hardware. In a typical configuration, a computing device includes one or more processors (CPUs), input / output interfaces, network interfaces, and memory.

[0125] The computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart block or blocks. Figure 1 The computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart block or blocks. Figure 1 The computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart block or blocks. The computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart block or blocks.

[0126] The computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart block or blocks. Figure 1 The computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart block or blocks. Figure 1 The computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart block or blocks. The computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart block or blocks.

[0127] The computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart block or blocks. Figure 1 The computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart block or blocks. Figure 1 The computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart block or blocks.

[0128] In a typical configuration, a computing device includes one or more processors (CPUs), input / output interfaces, network interfaces, and memory.

[0129] The memory can include non-persistent memory and / or volatile memory, such as random access memory (RAM) and / or cache memory, non-volatile memory, etc. in the form of computer-readable media. The memory is an example of computer-readable media.

[0130] Computer-readable media includes permanent and non-permanent, movable and non-movable media that can be implemented by any method or technology to store information. The information can be computer-readable instructions, data structures, program modules or other data. Examples of computer storage media include, but are not limited to, phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, compact disc read-only memory (CD-ROM), digital versatile disc (DVD) or other optical storage, magnetic cassette, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other non-transmission medium that can be used to store information accessible by a computing device. According to the definition herein, computer-readable media does not include transitory media such as modulated data signals and carriers.

[0131] It should also be noted that the terms "comprising", "including", or any other variant thereof are intended to cover non-exclusive inclusion, so that processes, methods, articles or devices including a series of elements not only include those elements, but also include other elements not explicitly listed, or inherent to such processes, methods, articles or devices. Without more limitations, the element defined by the statement "comprising a" does not exclude the presence of other identical elements in the process, method, article or device including the element.

[0132] From the above description, it can be seen that the above-mentioned embodiments of the present application achieve the following technical effects:

[0133] 1) The control method of the EGR valve of the application, the cooling temperature of the EGR cooler in the EGR system and the current opening of the EGR valve are obtained, and the cooling efficiency of the EGR cooler is calculated. In the case where the cooling efficiency is less than the first preset threshold, the product of the cooling efficiency, the correction factor and the current opening of the EGR valve is calculated to obtain the target opening of the EGR valve. In the case where the cooling efficiency is greater than the first preset threshold and the cooling temperature is greater than the second preset threshold, the EGR valve is controlled to be closed. In this way, by monitoring the cooling efficiency and the cooling temperature of the EGR cooler, when the EGR cooling efficiency is low or the cooling temperature is too high, the flow of the EGR valve can be reduced or interrupted in time to avoid the EGR valve from being burned by hot gas. Compared with the prior art, after the EGR cooler fails, the high-temperature EGR waste flow still flows through the EGR valve, which can cause the EGR valve to burn. The application reduces or interrupts the flow of the EGR valve to avoid further EGR valve burning or damage, etc. Therefore, the problem of EGR valve burning caused by high-temperature exhaust gas in the prior art can be solved.

[0134] 2) The control device of the EGR valve of the application, the cooling temperature of the EGR cooler in the EGR system and the current opening of the EGR valve are obtained, and the cooling efficiency of the EGR cooler is calculated. In the case where the cooling efficiency is less than the first preset threshold, the product of the cooling efficiency, the correction factor and the current opening of the EGR valve is calculated to obtain the target opening of the EGR valve. In the case where the cooling efficiency is greater than the first preset threshold and the cooling temperature is greater than the second preset threshold, the EGR valve is controlled to be closed. In this way, by monitoring the cooling efficiency and the cooling temperature of the EGR cooler, when the EGR cooling efficiency is low or the cooling temperature is too high, the flow of the EGR valve can be reduced or interrupted in time to avoid the EGR valve from being burned by hot gas. Compared with the prior art, after the EGR cooler fails, the high-temperature EGR waste flow still flows through the EGR valve, which can cause the EGR valve to burn. The application reduces or interrupts the flow of the EGR valve to avoid further EGR valve burning or damage, etc. Therefore, the problem of EGR valve burning caused by high-temperature exhaust gas in the prior art can be solved.

[0135] The above is only the preferred embodiment of the application and is not intended to limit the application. Those skilled in the art can make various changes and modifications to the application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the application shall be included in the protection scope of the application.

Claims

1. A control method for an EGR valve, characterized in that, The EGR valve is included in the EGR system, which also includes an EGR cooler and a check valve. The EGR cooler, check valve, and EGR valve are connected in sequence, including: The temperature of the exhaust gas from the engine after it has been cooled by the EGR cooler is obtained, and the current opening degree of the EGR valve is obtained, wherein the EGR system is included in the engine. The cooling efficiency of the EGR cooler is calculated. If the cooling efficiency is less than or equal to a first preset threshold, a correction factor is obtained. The product of the cooling efficiency, the correction factor, and the current opening of the EGR valve is calculated to obtain the target opening of the EGR valve. If the target opening of the EGR valve is different from the current opening of the EGR valve, the opening of the EGR valve is controlled to be the target opening. The correction factor is used to correct the opening of the EGR valve, and the cooling efficiency is the efficiency of the EGR cooler in cooling the exhaust gas of the engine. When the cooling efficiency is greater than the first preset threshold and the temperature after cooling is greater than or equal to the second preset threshold, the EGR valve is controlled to close.

2. The control method according to claim 1, characterized in that, Calculating the cooling efficiency of the EGR cooler includes: The temperature of the exhaust gas from the engine before it is cooled by the EGR cooler is obtained to get the temperature before cooling. Calculate the ratio of the cooled temperature to the uncooled temperature, and calculate the difference between 1 and the ratio to obtain the cooling efficiency.

3. The control method according to claim 1, characterized in that, Obtain the correction factor, including: Obtain multiple historical post-cooling temperatures, multiple historical EGR valve flow rates, and historical correction factors corresponding to each historical post-cooling temperature and each historical EGR valve flow rate to obtain a one-to-one mapping relationship between post-cooling temperature, EGR valve flow rate, and correction factors; Obtain the current EGR valve flow rate, and determine the historical correction factor corresponding to the cooling temperature and the current EGR valve flow rate through the one-to-one mapping relationship between the cooling temperature, the EGR valve flow rate and the correction factor, and obtain the correction factor.

4. The control method according to claim 1, characterized in that, When the cooling efficiency is less than or equal to a first preset threshold, or when the cooling efficiency is greater than the first preset threshold and the cooled temperature is greater than or equal to a second preset threshold, the control method further includes: If the duration during which the cooling efficiency is less than or equal to the first preset threshold is greater than or equal to the first preset time period, the EGR cooler is controlled to generate an alarm signal to indicate that the EGR cooler is faulty. If the duration for which the cooling efficiency is greater than the first preset threshold is greater than or equal to the second preset time period, and the duration for which the temperature after cooling is greater than or equal to the second preset threshold is greater than or equal to the second preset time period, the EGR cooler is controlled to generate the alarm signal to indicate that the EGR cooler is faulty.

5. The control method according to claim 1, characterized in that, The control method further includes: Obtain the current torque of the engine, wherein the EGR system is included in the engine; If the cooling efficiency is less than or equal to the first preset threshold, the product of the cooling efficiency, the correction factor, and the current torque is calculated to obtain the target torque, and the engine is controlled to operate at the target torque. When the temperature after cooling is greater than or equal to the second preset threshold, the engine speed is controlled to idle.

6. The control method according to claim 1, characterized in that, The control method further includes: Obtain the current engine speed and current fuel level; The cooling efficiency threshold corresponding to the current speed and the current oil quantity is determined by a one-to-one mapping relationship between speed, oil quantity and cooling efficiency threshold, and the first preset threshold is obtained. The one-to-one mapping relationship between speed, oil quantity and cooling efficiency threshold includes multiple historical speeds and historical oil quantity and historical cooling efficiency threshold corresponding to each historical speed. The temperature threshold corresponding to the current rotation speed and the current oil quantity is determined by a one-to-one mapping relationship between rotation speed, oil quantity and the temperature threshold after cooling, and the second preset threshold is obtained. The one-to-one mapping relationship between rotation speed, oil quantity and the temperature threshold after cooling includes multiple historical rotation speeds and the historical oil quantity and historical temperature threshold corresponding to each historical rotation speed.

7. The control method according to claim 1, characterized in that, The temperature of the engine exhaust gas after being cooled by the EGR cooler is obtained, including: If the current opening of the EGR valve is greater than or equal to 0 and the engine in which the EGR system is located has no error, the temperature of the exhaust gas of the engine after being cooled by the EGR cooler is obtained, and the cooled temperature is obtained.

8. A control device for an EGR valve, characterized in that, The EGR valve is included in the EGR system, which also includes an EGR cooler and a check valve. The EGR cooler, check valve, and EGR valve are connected in sequence, including: The first acquisition unit is used to acquire the temperature of the exhaust gas of the engine after it has been cooled by the EGR cooler, and to acquire the current opening degree of the EGR valve, wherein the EGR system is included in the engine. A first control unit is configured to calculate the cooling efficiency of the EGR cooler, and if the cooling efficiency is less than or equal to a first preset threshold, obtain a correction factor, calculate the product of the cooling efficiency, the correction factor, and the current opening of the EGR valve to obtain the target opening of the EGR valve, and if the target opening of the EGR valve is different from the current opening of the EGR valve, control the opening of the EGR valve to be the target opening of the EGR valve. The correction factor is used to correct the opening of the EGR valve, and the cooling efficiency is the efficiency of the EGR cooler in cooling the exhaust gas of the engine. The second control unit is used to control the EGR valve to close when the cooling efficiency is greater than the first preset threshold and the temperature after cooling is greater than or equal to the second preset threshold.

9. A computer-readable storage medium, characterized in that, The computer-readable storage medium includes a stored program, wherein, when the program is executed, it controls the device on which the computer-readable storage medium is located to perform the control method according to any one of claims 1 to 7.

10. An electronic device, characterized in that, include: One or more processors, a memory, and one or more programs, wherein the one or more programs are stored in the memory and configured to be executed by the one or more processors, the one or more programs including methods for performing the control method according to any one of claims 1 to 7.

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