Method and device for controlling intake air quantity of engine based on low-pressure EGR system

Abstract

The present application discloses a method and device for controlling the intake air volume of an engine based on a low-pressure EGR system. The low-pressure EGR system includes a throttle module, a negative pressure valve module, an EGR valve module, and a supercharger module. The control method includes: determining the EGR operating condition of the engine based on the operating parameters of the engine; determining the operation sequence of the throttle module, the negative pressure valve module, the EGR valve module, and the supercharger module based on the EGR operating condition; determining the operation rate of the throttle module, the negative pressure valve module, the EGR valve module, and the supercharger module based on the EGR operating condition and a preset rate; and controlling the throttle module, the negative pressure valve module, the EGR valve module, and the supercharger module to execute the operation sequence and the operation rate. The technical solution provided by the present application can accurately control the intake air volume of an engine based on a low-pressure EGR system.

Description

Technical Field

[0001] The present application belongs to the field of engine technology, and in particular relates to a method and device for controlling the intake air volume of an engine based on a low-pressure EGR system. Background Art

[0002] To improve the thermal efficiency of gasoline engines, various companies have begun researching and mass-producing gasoline engines that utilize low-pressure exhaust gas recirculation (EGR) systems. Compared to traditional high-pressure EGR systems, low-pressure EGR systems significantly expand the engine's available EGR range, meeting the EGR requirements of common hybrid engine operating conditions and thus reducing fuel consumption.

[0003] At present, engines generally adopt high-pressure EGR systems. Compared with high-pressure EGR systems, low-pressure EGR systems have an additional negative pressure valve. The action of the negative pressure valve will affect the pressure and flow of the engine's intake system. Therefore, how to control the intake volume of engines based on low-pressure EGR systems is an urgent problem to be solved. Summary of the Invention

[0004] The embodiments of the present application provide a method and apparatus for controlling the intake air volume of an engine based on a low-pressure EGR system, thereby enabling precise control of the intake air volume of an engine based on a low-pressure EGR system, at least to a certain extent.

[0005] Other features and advantages of the present application will become apparent from the following detailed description, or may be learned in part by practice of the present application.

[0006] According to a first aspect of an embodiment of the present application, a method for controlling the intake air volume of an engine based on a low-pressure EGR system is provided. The low-pressure exhaust gas recirculation (EGR) system includes a throttle module, a negative pressure valve module, an EGR valve module, and a supercharger module. The control method includes:

[0007] determining an EGR operating condition of the engine according to operating parameters of the engine;

[0008] determining an operating sequence of the throttle module, the negative pressure valve module, the EGR valve module, and the supercharger module according to the EGR operating condition;

[0009] Determining the action rates of the throttle module, the negative pressure valve module, the EGR valve module, and the supercharger module according to the EGR operating condition and a preset rate;

[0010] The throttle module, the negative pressure valve module, the EGR valve module, and the supercharger module are controlled to execute the action sequence and the action rate.

[0011] In some embodiments of the present application, based on the aforementioned solution, the operating parameters include speed and load, and determining the EGR operating condition of the engine according to the engine operating parameters includes:

[0012] determining a first state of the engine according to whether the speed and the load meet operating conditions of a low-pressure EGR system, wherein the first state includes being in an EGR zone or being outside an EGR zone;

[0013] determining a second state of the engine according to whether the speed and the load change, wherein the second state includes being in a steady state or in a transient state;

[0014] The EGR operating condition of the engine is determined according to the first state and the second state.

[0015] In some embodiments of the present application, based on the aforementioned solution, determining the first state of the engine according to whether the speed and the load meet the operating conditions of the low-pressure EGR system includes:

[0016] determining that the engine is in the EGR zone when the speed and the load meet the operating conditions of the low-pressure EGR system;

[0017] When the rotation speed and the load do not satisfy the operating conditions, it is determined that the engine is outside the EGR region.

[0018] In some embodiments of the present application, based on the aforementioned solution, determining the second state of the engine according to whether the speed and the load change, where the second state includes being in a steady state or in a transient state, includes:

[0019] determining that the engine is in the transient state when at least one of the speed and the load changes;

[0020] When neither the speed nor the load changes, it is determined that the engine is in the steady state.

[0021] In some embodiments of the present application, based on the aforementioned solution, determining the EGR operating condition of the engine according to the first state and the second state includes:

[0022] Determine the operating condition in which the first state is outside the EGR region and the second state is in the steady state as the first operating condition;

[0023] Determining the operating condition in which the first state is in the EGR region and the second state is in the steady state as a second operating condition;

[0024] Determining the operating condition in which the first state is outside the EGR region and the second state is in the transient state as a third operating condition;

[0025] Determining an operating condition in which the first state is in the EGR region, the second state is in the transient state, and the rate of change of the speed and / or the rate of change of the load is less than a preset value as a fourth operating condition;

[0026] Determining an operating condition in which the first state is in the EGR region, the second state is in the transient state, and the rate of change of the speed and / or the rate of change of the load is greater than a preset value as a fifth operating condition;

[0027] Determine the operating condition in which the first state is switched from being in the EGR area to being outside the EGR area, the second state is in the transient state, and the load is reduced as a sixth operating condition;

[0028] Determine the operating condition in which the first state is switched from being in the EGR area to being outside the EGR area, the second state is in the transient state, and the load increases as a seventh operating condition;

[0029] Switching the first state from outside the EGR zone to inside the EGR zone, wherein the second state is the transient state and the load is reduced, and is determined as the eighth operating condition;

[0030] The first state is switched from being outside the EGR area to being inside the EGR area, and the second state is the operating condition in the transient state and the load increases, which is determined as the ninth operating condition.

[0031] In some embodiments of the present application, based on the aforementioned solution, determining the operation sequence of the throttle module, the negative pressure valve module, the EGR valve module, and the supercharger module according to the EGR operating condition includes:

[0032] When the EGR operating condition is the first operating condition or the second operating condition, keeping the throttle module, the negative pressure valve module, the EGR valve module and the supercharger module inactive;

[0033] When the EGR operating condition is the third operating condition, controlling the throttle module and the supercharger module to operate in sequence, and keeping the negative pressure valve module and the EGR valve module inactive;

[0034] When the EGR operating condition is the fourth operating condition, the fifth operating condition, the sixth operating condition, the seventh operating condition, the eighth operating condition or the ninth operating condition, the throttle module, the negative pressure valve module, the EGR valve module and the supercharger module are controlled to operate in a preset order.

[0035] In some embodiments of the present application, based on the aforementioned solution, when the EGR operating condition is the fourth operating condition, the fifth operating condition, the sixth operating condition, the seventh operating condition, the eighth operating condition, or the ninth operating condition, controlling the throttle module, the negative pressure valve module, the EGR valve module, and the supercharger module to operate in a preset sequence includes:

[0036] When the EGR operating condition is the fourth operating condition, controlling the negative pressure valve module, the EGR valve module, the throttle module and the supercharger module to operate in sequence;

[0037] When the EGR operating condition is the fifth operating condition, controlling the EGR valve module, the throttle module, the supercharger module and the negative pressure valve module to operate in sequence;

[0038] When the EGR operating condition is the sixth operating condition, controlling the throttle module, the EGR valve module, the supercharger module and the negative pressure valve module to operate in sequence;

[0039] When the EGR operating condition is the seventh operating condition, controlling the EGR valve module, the throttle module, the supercharger module and the negative pressure valve module to operate in sequence;

[0040] When the EGR operating condition is the eighth operating condition, controlling the negative pressure valve module, the supercharger module, the EGR valve module and the throttle module to operate in sequence;

[0041] When the EGR operating condition is the ninth operating condition, the throttle module, the negative pressure valve module, the EGR valve module and the supercharger module are controlled to operate in sequence.

[0042] In some embodiments of the present application, based on the above solution, the control method further includes:

[0043] determining an air volume change rate according to a required air volume and an actual air volume of the engine;

[0044] The action time intervals among the throttle module, the negative pressure valve module, the EGR valve module and the supercharger module are determined according to the gas volume change rate, wherein the gas volume change rate is negatively correlated with the action time intervals.

[0045] In some embodiments of the present application, based on the aforementioned solution, the preset rate includes a first rate, a second rate, or a third rate that increases sequentially, and determining the action rates of the throttle module, the negative pressure valve module, the EGR valve module, and the supercharger module according to the EGR operating condition and the preset rate includes:

[0046] When the EGR operating condition is the first operating condition or the second operating condition, controlling the action rates of the throttle module, the negative pressure valve module, the EGR valve module and the supercharger module to be zero;

[0047] When the EGR operating condition is the third operating condition, controlling the action rates of the throttle module and the supercharger module to be the second rate, and controlling the action rates of the negative pressure valve module and the EGR valve module to be zero;

[0048] When the EGR operating condition is the fourth operating condition, the fifth operating condition, the sixth operating condition, the seventh operating condition, the eighth operating condition or the ninth operating condition, the action rates of the throttle module, the negative pressure valve module and the supercharger module are controlled to be the preset rate, and the action rate of the EGR valve module is controlled to be the preset rate multiplied by a correction coefficient.

[0049] In some embodiments of the present application, based on the aforementioned solution, controlling the action rates of the throttle module, the negative pressure valve module, and the supercharger module to be the preset rate includes:

[0050] When the EGR operating condition is the fourth operating condition, the fifth operating condition, the seventh operating condition, or the ninth operating condition, controlling the action rate of the throttle module to be the third rate, and the action rates of the negative pressure valve module and the supercharger module to be the first rate;

[0051] When the EGR operating condition is the sixth operating condition, the action rate of the throttle module is controlled to be the second rate, and the action rates of the negative pressure valve module and the supercharger module are both controlled to be the third rate;

[0052] When the EGR operating condition is the eighth operating condition, the action rates of the throttle module and the supercharger module are controlled to be the third rate, and the action rate of the negative pressure valve module is controlled to be the second rate.

[0053] In some embodiments of the present application, based on the above solution, the correction coefficient includes a knock correction coefficient, and the action rate of controlling the EGR valve module is the preset rate multiplied by the correction coefficient, including:

[0054] When the EGR operating condition is the fifth operating condition, controlling the actuation rate of the EGR valve module is the third rate multiplied by the knock correction coefficient;

[0055] When the EGR operating condition is the sixth operating condition or the seventh operating condition, the actuation rate of the EGR valve module is controlled by multiplying the second rate by the knock correction coefficient.

[0056] In some embodiments of the present application, based on the aforementioned solution, the correction coefficient includes a knock correction coefficient and a gas volume correction coefficient, and the action rate of controlling the EGR valve module is the preset rate multiplied by the correction coefficient, including:

[0057] When the EGR operating condition is the fourth operating condition, the eighth operating condition, or the ninth operating condition, the action rate of controlling the EGR valve module is the first rate multiplied by the knock correction coefficient and the gas volume correction coefficient.

[0058] In some embodiments of the present application, based on the aforementioned solution, the control method further includes: determining the knock correction coefficient according to the knock recession angle of the engine and a preset mapping relationship.

[0059] In some embodiments of the present application, based on the aforementioned solution, the control method further includes: determining the air volume correction coefficient according to the actual air intake volume of the engine and a preset formula.

[0060] According to a second aspect of an embodiment of the present application, a device for controlling the intake air volume of an engine based on a low-pressure EGR system is provided. The low-pressure exhaust gas recirculation (EGR) system includes a throttle module, a negative pressure valve module, an EGR valve module, and a supercharger module. The control device includes:

[0061] An EGR operating condition determining unit, configured to determine the EGR operating condition of the engine according to operating parameters of the engine;

[0062] an action sequence determining unit, configured to determine an action sequence of the throttle module, the negative pressure valve module, the EGR valve module, and the supercharger module according to the EGR operating condition;

[0063] an action rate determination unit, configured to determine action rates of the throttle module, the negative pressure valve module, the EGR valve module, and the supercharger module according to the EGR operating condition and a preset rate;

[0064] An action execution unit is used to control the throttle module, the negative pressure valve module, the EGR valve module and the supercharger module to execute the action sequence and the action rate.

[0065] According to a third aspect of an embodiment of the present application, a control device for the intake air volume of an engine based on a low-pressure EGR system is provided, comprising a processor and a memory, wherein the memory stores computer program instructions that can be executed by the processor, and when the processor executes the computer program instructions, the steps of the method described in any one of the first aspects above are implemented.

[0066] According to a fourth aspect of an embodiment of the present application, a computer-readable storage medium is provided, in which computer program instructions are stored. When the computer program instructions are executed by a processor, the processor is prompted to implement the steps of the method described in any one of the first aspects above.

[0067] In the present application, the EGR operating condition of the engine is determined according to the operating parameters of the engine; the action sequence of the throttle module, the negative pressure valve module, the EGR valve module and the supercharger module is determined according to the EGR operating condition; the action rate of the throttle module, the negative pressure valve module, the EGR valve module and the supercharger module is determined according to the EGR operating condition and a preset rate; and the throttle module, the negative pressure valve module, the EGR valve module and the supercharger module are controlled to execute the action sequence and the action rate, thereby achieving precise control of the intake amount of the engine based on the low-pressure EGR system.

[0068] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0069] The accompanying drawings are incorporated into and constitute a part of the specification, illustrating embodiments consistent with the present application and, together with the specification, serving to explain the principles of the present application. It is obvious that the drawings described below are merely some embodiments of the present application, and a person skilled in the art can derive other drawings based on these drawings without inventive effort. In the drawings:

[0070] Figure 1 A schematic structural diagram of a low-pressure EGR system in one embodiment is shown;

[0071] Figure 2 A flow chart of a method for controlling the intake air volume of an engine based on a low-pressure EGR system in one embodiment is shown;

[0072] Figure 3 A detailed schematic diagram of step 201 in one embodiment is shown;

[0073] Figure 4 A detailed schematic diagram of step 202 in one embodiment is shown;

[0074] Figure 5 A detailed schematic diagram of step 203 in one embodiment is shown;

[0075] Figure 6 A block diagram of a device for controlling the intake air quantity of an engine based on a low-pressure EGR system in one embodiment is shown;

[0076] Figure 7 A schematic structural diagram of an engine intake air quantity control device based on a low-pressure EGR system in one embodiment is shown. DETAILED DESCRIPTION

[0077] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0078] In addition, described feature, structure or characteristic can be combined in one or more embodiments in any suitable manner.In the following description, many specific details are provided so as to provide a full understanding of the embodiments of the present application. However, it will be appreciated by those skilled in the art that the technical scheme of the present application can be put into practice without one or more of the specific details, or other methods, components, devices, steps etc. can be adopted. In other cases, known methods, devices, implementations or operations are not shown or described in detail to avoid blurring the various aspects of the application.

[0079] The block diagrams shown in the accompanying drawings are merely functional entities and do not necessarily correspond to physically separate entities. That is, these functional entities may be implemented in software, in one or more hardware modules or integrated circuits, or in different networks and / or processor devices and / or microcontroller devices.

[0080] The flowcharts shown in the accompanying drawings are for illustrative purposes only and do not necessarily include all contents and operations / steps, nor must they be executed in the order described. For example, some operations / steps may be decomposed, while others may be combined or partially combined. Therefore, the actual execution order may vary depending on the actual situation.

[0081] It should also be noted that the terms "first," "second," and the like in the specification and claims of this application and the accompanying drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or precedence. It should be understood that the terms used in this manner are interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than that shown or described.

[0082] In order to make those skilled in the art better understand this application, first combine Figure 1 The low-pressure EGR system involved in this application is briefly described.

[0083] Figure 1 FIG. 1 shows a schematic structural diagram of a low-pressure EGR system in one embodiment. Figure 1 As shown, the low-pressure EGR system includes a throttle module, a negative pressure valve module, an EGR valve module, a supercharger module, an EGR cooler, an intercooler, a catalyst, a gasoline particulate filter (GPF), and other components. The throttle module includes a throttle valve and its corresponding actuator, the negative pressure valve module includes a negative pressure valve and its corresponding actuator, the EGR valve module includes an EGR valve and its corresponding actuator, and the supercharger module includes a supercharger and its corresponding actuator. In the low-pressure EGR system, reducing the valve opening of the negative pressure valve module creates negative pressure, which generates flow dynamics for the gas in the low-pressure EGR system.

[0084] The low-pressure EGR system extracts exhaust gas from the GPF, passing it through the EGR cooler and EGR valve module before entering the compressor line. After passing through the air filter and the negative pressure valve module, the air mixes with the exhaust gas in the compressor line before entering the compressor, passing through the intercooler and throttle module and entering the engine cylinders. The engine's air intake volume is determined by the throttle module, negative pressure valve module, EGR valve module, and supercharger module.

[0085] Figure 2 FIG. 1 is a flow chart showing a method for controlling the intake air volume of an engine based on a low-pressure EGR system in one embodiment. Figure 2 As shown, a method for controlling the intake air amount of an engine based on a low-pressure EGR system is provided. The method may include the following steps 201 to 204.

[0086] Step 201: Determine the EGR operating condition of the engine according to the operating parameters of the engine.

[0087] Among them, the operating parameters of the engine may include parameters such as the engine speed, load, torque, etc., which are not limited in this embodiment of the present application.

[0088] The EGR operating condition of the engine refers to the operating condition related to the low-pressure EGR system, including whether it is in the EGR area or outside the EGR area.

[0089] During the implementation process, the electronic control unit (ECU) of the vehicle can obtain the operating parameters of the engine and determine the EGR operating condition of the engine according to the operating parameters.

[0090] Figure 3 A detailed schematic diagram of step 201 in one embodiment is shown. Step 201 may include the following steps:

[0091] Step 301, determining a first state of the engine based on whether the speed and load meet the operating conditions of the low-pressure EGR system, wherein the first state includes being in the EGR zone or being outside the EGR zone;

[0092] Step 302: determining a second state of the engine according to whether the speed and load change, wherein the second state includes being in a steady state or in a transient state;

[0093] Step 303: Determine the EGR operating condition of the engine according to the first state and the second state.

[0094] Among them, the operating conditions of the low-pressure EGR system can be set according to specific circumstances. For example, when the engine speed is between 20% and 80% of the rated speed and the engine load is between 15% and 90% of the maximum rated load, the low-pressure EGR system needs to be operated. The operating conditions of the low-pressure EGR system are that the speed is between 20% and 80% of the rated speed and the load is between 15% and 90% of the maximum rated load.

[0095] In some embodiments, when the speed and load meet the operating conditions of the low-pressure EGR system, the engine is determined to be in the EGR zone; when the speed and load do not meet the operating conditions, the engine is determined to be outside the EGR zone.

[0096] Taking the above operating conditions as an example, if the engine speed is between 20% and 80% of the rated speed and the load is between 15% and 90% of the maximum rated load, the engine is determined to be in the EGR zone; otherwise, the engine is determined to be outside the EGR zone.

[0097] In some embodiments, when at least one of the speed and the load changes, the engine is determined to be in a transient state; when neither the speed nor the load changes, the engine is determined to be in a steady state.

[0098] It can be understood that if either the speed or the load changes, or both of them change, it is determined that the engine is in a transient state; if neither of them changes, it is determined that the engine is in a steady state.

[0099] In some embodiments, the operating condition in which the first state is outside the EGR zone and the second state is in a steady state can be determined as the first operating condition; the operating condition in which the first state is in the EGR zone and the second state is in a steady state can be determined as the second operating condition; the operating condition in which the first state is outside the EGR zone and the second state is in a transient state can be determined as the third operating condition; the operating condition in which the first state is in the EGR zone, the second state is in a transient state, and the rate of change of the speed and / or the rate of change of the load is less than a preset value can be determined as the fourth operating condition; the operating condition in which the first state is in the EGR zone, the second state is in a transient state, and the rate of change of the speed and / or the rate of change of the load is less than a preset value can be determined as the fourth operating condition; The operating condition in which the rate is greater than the preset value is determined as the fifth operating condition; the operating condition in which the first state is switched from being in the EGR area to being outside the EGR area, the second state is in a transient state, and the load is reduced is determined as the sixth operating condition; the operating condition in which the first state is switched from being in the EGR area to being outside the EGR area, the second state is in a transient state, and the load is increased is determined as the seventh operating condition; the operating condition in which the first state is switched from being outside the EGR area to being in the EGR area, the second state is in a transient state, and the load is reduced is determined as the eighth operating condition; the operating condition in which the first state is switched from being outside the EGR area to being in the EGR area, the second state is in a transient state, and the load is increased is determined as the ninth operating condition.

[0100] It is understandable that the first operating condition may also be referred to as a steady-state operating condition outside the EGR region. Under this operating condition, there is no EGR request, and the engine speed and load remain unchanged, and the engine operates in a steady state.

[0101] The second operating condition may also be referred to as a steady-state operating condition in the EGR region. Under this operating condition, there is an EGR request, and the engine speed and load remain unchanged, and the engine operates in a steady state.

[0102] The third operating condition may also be referred to as an out-of-EGR transient operating condition. Under this operating condition, there is no EGR request, and the engine speed and / or load changes, resulting in transient engine operation.

[0103] The fourth operating condition can also be called the transient operation in the EGR area and the low-pressure EGR system is continuously turned on operating condition. Under this operating condition, there is an EGR request, and the engine speed and / or load changes, the engine operates transiently, but because the rate of change of speed and / or load is small, the low-pressure EGR system is continuously turned on during the transient operation of the engine.

[0104] The fifth operating condition can also be called the transient operation in the EGR area and the instantaneous shutdown of the low-pressure EGR system. Under this operating condition, there is an EGR request, and the engine speed and / or load changes, and the engine runs transiently, but due to the large rate of change of speed and / or load, the low-pressure EGR system is closed during the transient operation of the engine.

[0105] The sixth operating condition can also be called the EGR area transient downward out of the EGR area operating condition. Under this operating condition, the operating point is reduced from the load in the EGR area to outside the EGR area.

[0106] The seventh operating condition can also be called the EGR zone transient upward out of the EGR zone operating condition. Under this operating condition, the operating point increases the load from the EGR zone to outside the EGR zone.

[0107] The eighth operating condition can also be called the transient downward-into-EGR-area operating condition outside the EGR area. Under this operating condition, the operating point reduces the load from outside the EGR area to inside the EGR area.

[0108] The ninth operating condition can also be called the transient upward-to-EGR-area operating condition outside the EGR area. Under this operating condition, the operating point increases the load from outside the EGR area to inside the EGR area.

[0109] Step 202 : determining the operation sequence of the throttle module, the negative pressure valve module, the EGR valve module, and the supercharger module according to the EGR operating condition.

[0110] It is understandable that the action sequence of the throttle module, negative pressure valve module, EGR valve module and supercharger module is different depending on the EGR working conditions. By subdividing the EGR working conditions and then controlling the above four modules in an orderly manner according to different EGR working conditions, not only can the precise control of the engine intake volume be achieved, but also the smoothness of the engine can be guaranteed.

[0111] Figure 4 A detailed schematic diagram of step 202 in one embodiment is shown, as shown in FIG. Figure 4 As shown, step 202 may include the following steps:

[0112] Step 401: When the EGR operating condition is the first operating condition or the second operating condition, the throttle module, the negative pressure valve module, the EGR valve module, and the supercharger module are kept inactive.

[0113] Step 402 , when the EGR operating condition is the third operating condition, controlling the throttle module and the supercharger module to operate in sequence, and keeping the negative pressure valve module and the EGR valve module inactive;

[0114] Step 403 , when the EGR operating condition is the fourth operating condition, the fifth operating condition, the sixth operating condition, the seventh operating condition, the eighth operating condition or the ninth operating condition, the throttle module, the negative pressure valve module, the EGR valve module and the supercharger module are controlled to operate in a preset order.

[0115] In some embodiments, when the EGR operating condition is the fourth operating condition, the negative pressure valve module, the EGR valve module, the throttle module and the supercharger module are controlled to operate in sequence; when the EGR operating condition is the fifth operating condition, the EGR valve module, the throttle module, the supercharger module and the negative pressure valve module are controlled to operate in sequence; when the EGR operating condition is the sixth operating condition, the throttle module, the EGR valve module, the supercharger module and the negative pressure valve module are controlled to operate in sequence; when the EGR operating condition is the seventh operating condition, the EGR valve module, the throttle module, the supercharger module and the negative pressure valve module are controlled to operate in sequence; when the EGR operating condition is the eighth operating condition, the negative pressure valve module, the supercharger module, the EGR valve module and the throttle module are controlled to operate in sequence; when the EGR operating condition is the ninth operating condition, the throttle module, the negative pressure valve module, the EGR valve module and the supercharger module are controlled to operate in sequence.

[0116] Assuming that the EGR operating conditions from the first to the ninth operating conditions are from A1 to A9, the throttle module is M1, the negative pressure valve module is M2, the EGR valve module is M3, and the supercharger module is M4, X represents no action, and 1 to 4 represent the action sequence, the operation sequence of each module can be referred to in the following Table 1:

[0117] Table 1

[0118] A1 A2 A3 A4 A5 A6 A7 A8 A9 M1 X X 1 3 2 1 2 4 1 M2 X X X 1 4 4 4 1 2 M3 X X X 2 1 2 1 3 3 M4 X X 2 4 3 3 3 2 4

[0119] As shown in Table 1, in the first or second operating condition, the engine is in a steady state, and the throttle module, negative pressure valve module, EGR valve module and supercharger module are all inactive; in the third operating condition, the engine is outside the EGR area and is operating transiently. At this time, the negative pressure valve module and the EGR valve module are both inactive, and the low-pressure EGR system is not opened; in the fourth to ninth operating conditions, the engine is in a transient state, and the throttle module, negative pressure valve module, EGR valve module and supercharger module all need to operate in a preset order.

[0120] It should be noted that, in the fourth to ninth operating conditions, the action sequence of the four modules may also be other sequences besides the sequence shown in Table 1. The sequence shown in Table 1 is a preferred sequence. The four modules can operate in this sequence to make the engine smoother.

[0121] In some embodiments, the ECU can determine the air volume change rate based on the required air volume and actual air volume of the engine; determine the action time interval between the throttle module, the negative pressure valve module, the EGR valve module and the supercharger module based on the air volume change rate, wherein the air volume change rate is negatively correlated with the action time interval.

[0122] It can be understood that the air volume change rate can be obtained by dividing the difference between the required air volume and the actual air volume by the actual air volume. The larger the air volume change rate, the shorter the action time interval, thereby quickly controlling the engine's air volume; the smaller the air volume change rate, the longer the action time interval.

[0123] Step 203 : determining the action rates of the throttle module, the negative pressure valve module, the EGR valve module, and the supercharger module according to the EGR operating condition and the preset rate.

[0124] It is understandable that the preset rate may include multiple rates, and the throttle module, the negative pressure valve module, the EGR valve module and the supercharger module may be controlled to operate at different rates according to different EGR operating conditions.

[0125] Figure 5 A detailed schematic diagram of step 203 in one embodiment is shown, as shown in FIG. Figure 5 As shown, step 203 may include the following steps:

[0126] Step 501, when the EGR operating condition is the first operating condition or the second operating condition, controlling the action rates of the throttle module, the negative pressure valve module, the EGR valve module and the supercharger module to be zero;

[0127] Step 502 , when the EGR operating condition is the third operating condition, controlling the actuation rates of the throttle module and the supercharger module to be the second rate, and controlling the actuation rates of the negative pressure valve module and the EGR valve module to be zero;

[0128] Step 503, when the EGR operating condition is the fourth operating condition, the fifth operating condition, the sixth operating condition, the seventh operating condition, the eighth operating condition or the ninth operating condition, the action rate of the throttle module, the negative pressure valve module and the supercharger module is controlled to be a preset rate, and the action rate of the EGR valve module is controlled to be the preset rate multiplied by a correction coefficient.

[0129] The preset rate may include a first rate, a second rate, or a third rate, wherein the first rate is a slower rate, the second rate is a basic rate, and the third rate is a faster rate.

[0130] In the first or second operating conditions, none of the four modules are active, so their actuation rates are all zero. In the third operating condition, only the throttle and supercharger modules are active, and the base actuation rates for these two modules can be used. In the fourth through ninth operating conditions, the actuation rates of the four modules can be designed based on the specific operating conditions.

[0131] In some embodiments, when the EGR operating condition is the fourth operating condition, the fifth operating condition, the seventh operating condition or the ninth operating condition, the action rate of the throttle module is controlled to be the third rate, and the action rates of the negative pressure valve module and the supercharger module are both the first rate; when the EGR operating condition is the sixth operating condition, the action rate of the throttle module is controlled to be the second rate, and the action rates of the negative pressure valve module and the supercharger module are both the third rate; when the EGR operating condition is the eighth operating condition, the action rates of the throttle module and the supercharger module are both controlled to be the third rate, and the action rate of the negative pressure valve module is the second rate.

[0132] It is understandable that when the engine is in a transient state, the EGR valve module's action rate is too fast, which can easily cause knock and lead to engine damage. Therefore, it is necessary to use the knock correction coefficient to correct the action rate of the EGR module to slow down the action rate of the EGR valve module when more knock occurs.

[0133] In some embodiments, the correction coefficient includes a knock correction coefficient, and the action rate of the EGR valve module controlled is a preset rate multiplied by the correction coefficient, which may include: when the EGR operating condition is the fifth operating condition, the action rate of the EGR valve module controlled is a third rate multiplied by the knock correction coefficient; when the EGR operating condition is the sixth operating condition or the seventh operating condition, the action rate of the EGR valve module controlled is the second rate multiplied by the knock correction coefficient.

[0134] In other embodiments, the correction coefficient includes a knock correction coefficient and an air volume correction coefficient, and the action rate of the EGR valve module is controlled to be a preset rate multiplied by the correction coefficient, which may include: when the EGR operating condition is the fourth operating condition, the eighth operating condition or the ninth operating condition, the action rate of the EGR valve module is controlled to be the first rate multiplied by the knock correction coefficient and the air volume correction coefficient.

[0135] It should be noted that in order to rapidly increase the EGR rate and minimize the engine's transient fuel consumption, the EGR valve module's actuation rate needs to be corrected based on the engine's actual intake air volume. For operating conditions 5, 6, and 7, the engine's actual intake air volume is low, so the air volume correction factor is not needed to correct the EGR valve module's actuation rate. For operating conditions 4, 8, and 9, the engine's actual intake air volume is high, requiring the EGR valve module's actuation rate to be accelerated. Therefore, the air volume correction factor is used to correct the EGR valve module's actuation rate. This speeds up the EGR valve module's actuation rate, improves the EGR rate's response speed at medium and high loads, and reduces transient fuel consumption.

[0136] Assuming that the EGR operating conditions from the first to the ninth operating conditions are from A1 to A9, the throttle module is M1, the negative pressure valve module is M2, the EGR valve module is M3, and the supercharger module is M4, X represents the action rate zero, 1 represents the first rate, 2 represents the second rate, 3 represents the third rate, i represents the knock correction coefficient, and n represents the gas volume correction coefficient. The operating rates of each module can be referred to in the following Table 2:

[0137] Table 2

[0138] A1 A2 A3 A4 A5 A6 A7 A8 A9 M1 X X 2 3 3 2 3 3 3 M2 X X X 1 1 3 1 2 1 M3 X X X 1*i*n 3*i 2*i 2*i 1*i*n 1*i*n M4 X X 2 1 1 3 1 3 1

[0139] It can be understood that the first rate, the second rate, the third rate, the knock correction coefficient and the gas volume correction coefficient can be set according to actual conditions, and the embodiments of the present application do not limit this.

[0140] In some embodiments, the knock correction coefficient may be determined based on the knock recession angle of the engine and a preset mapping relationship.

[0141] During implementation, a preset mapping relationship between knock recession angle and knock correction coefficient can be obtained through experimentation. Specifically, if the engine experiences knock during transient conditions, the knock recession angle is recorded. After 300 knocks have occurred, the average of the 300 knock recession angles, the cumulative duration of the 300 knocks, and the corresponding knock correction coefficient are calculated. The knock correction coefficient is then updated every 300 knocks.

[0142] The preset mapping relationship can be referred to in Table 3 below:

[0143] Table 3

[0144] 2 3 4 5 6 8 1000 0.85 0.75 0.65 0.5 0.3 0.2 3000 0.91 0.78 0.7 0.54 0.34 0.2 6000 1.00 0.85 0.75 0.61 0.41 0.2 10000 1.00 0.9 0.8 0.7 0.5 0.2

[0145] In Table 3, the first row is the average value of the knock retreat angle, the first column is the cumulative duration, and the decimal in the middle is the knock correction coefficient.

[0146] The ECU can look up a table based on the engine's knock recession angle and knock duration to obtain the corresponding knock correction coefficient, and use the knock correction coefficient to correct the preset rate.

[0147] In some embodiments, the air volume correction coefficient may be determined based on the actual air intake volume of the engine and a preset formula.

[0148] Specifically, the formula n=(m+450) / 800 may be used, wherein n is the air volume correction coefficient, and m is the actual intake air volume.

[0149] Step 204 : Control the throttle module, the negative pressure valve module, the EGR valve module, and the supercharger module to execute an action sequence and an action rate.

[0150] It is understood that once the action sequence and action rate of each module are determined, they can be written into the calibration software and executed. By observing indicators such as the tracking speed and fluctuation amplitude of the actual intake volume, the difference between the actual intake volume and the estimated intake volume, engine knock, and fuel consumption results, the action time interval, action rate, knock correction factor, and air volume correction factor of each module can be adjusted to achieve the optimal actual intake volume.

[0151] The embodiments of the present application precisely classify EGR operating conditions and control the sequence and rate of operation of the throttle module, negative pressure valve module, EGR valve module, and supercharger module according to different operating conditions, thereby achieving precise control of engine intake volume and improving engine torque response speed and smoothness. Furthermore, the EGR valve module's operation rate is self-learned based on engine knock conditions, reducing engine knock and effectively protecting the engine. The EGR valve module's operation rate is adjusted based on the intake volume, maximizing the EGR rate and reducing transient fuel consumption.

[0152] The following describes an embodiment of the device of the present application, which can be used to implement the method for controlling the intake air volume of an engine based on a low-pressure EGR system described in the above-mentioned embodiment of the present application. For details not disclosed in the embodiment of the device of the present application, please refer to the embodiment of the method for controlling the intake air volume of an engine based on a low-pressure EGR system described in the above-mentioned embodiment of the present application.

[0153] See also Figure 6 , shows a block diagram of a control device for the intake air amount of an engine based on a low-pressure EGR system in an embodiment of the present application.

[0154] like Figure 6 As shown, the control device for the intake amount of an engine based on a low-pressure EGR system in an embodiment of the present application may include: an EGR operating condition determination unit 601, an action sequence determination unit 602, an action rate determination unit 603 and an action execution unit 604, wherein the EGR operating condition determination unit 601 is used to determine the EGR operating condition of the engine according to the operating parameters of the engine; the action sequence determination unit 602 is used to determine the action sequence of the throttle module, the negative pressure valve module, the EGR valve module and the supercharger module according to the EGR operating condition; the action rate determination unit 603 is used to determine the action rate of the throttle module, the negative pressure valve module, the EGR valve module and the supercharger module according to the EGR operating condition and the preset rate; the action execution unit 604 is used to control the throttle module, the negative pressure valve module, the EGR valve module and the supercharger module to execute the action sequence and action rate.

[0155] In some embodiments of the present application, based on the aforementioned scheme, the operating parameters include speed and load, and the EGR operating condition determination unit 601 is also used to determine the first state of the engine according to whether the speed and load meet the operating conditions of the low-pressure EGR system, wherein the first state includes being in the EGR area or outside the EGR area; determine the second state of the engine according to whether the speed and load change, wherein the second state includes being in a steady state or in a transient state; determine the EGR operating condition of the engine according to the first state and the second state.

[0156] In some embodiments of the present application, based on the aforementioned scheme, the EGR operating condition determination unit 601 is also used to determine that the engine is in the EGR zone when the speed and load meet the operating conditions of the low-pressure EGR system; and to determine that the engine is outside the EGR zone when the speed and load do not meet the operating conditions.

[0157] In some embodiments of the present application, based on the aforementioned scheme, the EGR operating condition determination unit 601 is also used to determine that the engine is in a transient state when at least one of the speed and load changes; and to determine that the engine is in a steady state when neither the speed nor the load changes.

[0158] In some embodiments of the present application, based on the aforementioned scheme, the EGR operating condition determination unit 601 is further used to determine the operating condition in which the first state is outside the EGR zone and the second state is in a steady state as the first operating condition; determine the operating condition in which the first state is in the EGR zone and the second state is in a steady state as the second operating condition; determine the operating condition in which the first state is outside the EGR zone and the second state is in a transient state as the third operating condition; determine the operating condition in which the first state is in the EGR zone, the second state is in a transient state, and the rate of change of the speed and / or the rate of change of the load is less than a preset value as the fourth operating condition; determine the operating condition in which the first state is in the EGR zone, the second state is in a transient state, and the rate of change of the speed and / or the rate of change of the load is less than a preset value as the fourth operating condition; determine the operating condition in which the first state is in the EGR zone, the second state is in a transient state, and the speed is less than a preset value as the fourth operating condition. The operating condition in which the rate of change of and / or the rate of change of load is greater than a preset value is determined as the fifth operating condition; the operating condition in which the first state is switched from being in the EGR area to being outside the EGR area, the second state is in a transient state, and the load is reduced is determined as the sixth operating condition; the operating condition in which the first state is switched from being in the EGR area to being outside the EGR area, the second state is in a transient state, and the load is increased is determined as the seventh operating condition; the operating condition in which the first state is switched from being outside the EGR area to being in the EGR area, the second state is in a transient state, and the load is reduced is determined as the eighth operating condition; the operating condition in which the first state is switched from being outside the EGR area to being in the EGR area, the second state is in a transient state, and the load is increased is determined as the ninth operating condition.

[0159] In some embodiments of the present application, based on the aforementioned scheme, the action sequence determination unit 602 is also used to keep the throttle module, the negative pressure valve module, the EGR valve module and the supercharger module inactive when the EGR operating condition is the first operating condition or the second operating condition; when the EGR operating condition is the third operating condition, control the throttle module and the supercharger module to operate in sequence, and keep the negative pressure valve module and the EGR valve module inactive; when the EGR operating condition is the fourth operating condition, the fifth operating condition, the sixth operating condition, the seventh operating condition, the eighth operating condition or the ninth operating condition, control the throttle module, the negative pressure valve module, the EGR valve module and the supercharger module to operate in a preset order.

[0160] In some embodiments of the present application, based on the above-mentioned scheme, the action sequence determination unit 602 is also used to control the negative pressure valve module, EGR valve module, throttle module and supercharger module to operate in sequence when the EGR operating condition is the fourth operating condition; control the EGR valve module, throttle module, supercharger module and negative pressure valve module to operate in sequence when the EGR operating condition is the fifth operating condition; control the throttle module, EGR valve module, supercharger module and negative pressure valve module to operate in sequence when the EGR operating condition is the sixth operating condition; control the throttle module, EGR valve module, supercharger module and negative pressure valve module to operate in sequence when the EGR operating condition is the seventh operating condition; control the EGR valve module, throttle module, supercharger module and negative pressure valve module to operate in sequence; control the negative pressure valve module, supercharger module, EGR valve module and throttle module to operate in sequence when the EGR operating condition is the eighth operating condition; control the negative pressure valve module, supercharger module, EGR valve module and throttle module to operate in sequence; and control the throttle module, negative pressure valve module, EGR valve module and supercharger module to operate in sequence when the EGR operating condition is the ninth operating condition.

[0161] In some embodiments of the present application, based on the above solution, a time interval determination unit (not shown) is further included, which is used to determine the air volume change rate according to the required air volume and the actual air volume of the engine;

[0162] The action time intervals among the throttle module, the negative pressure valve module, the EGR valve module and the supercharger module are determined according to the air volume change rate, wherein the air volume change rate is negatively correlated with the action time interval.

[0163] In some embodiments of the present application, based on the above-mentioned scheme, the action rate determination unit 603 is also used to control the action rate of the throttle module, the negative pressure valve module, the EGR valve module and the supercharger module to be zero when the EGR operating condition is the first operating condition or the second operating condition; when the EGR operating condition is the third operating condition, the action rates of the throttle module and the supercharger module are controlled to be the second rate, and the action rates of the negative pressure valve module and the EGR valve module are controlled to be zero; when the EGR operating condition is the fourth operating condition, the fifth operating condition, the sixth operating condition, the seventh operating condition, the eighth operating condition or the ninth operating condition, the action rates of the throttle module, the negative pressure valve module and the supercharger module are controlled to be preset rates, and the action rate of the EGR valve module is controlled to be the preset rate multiplied by the correction coefficient.

[0164] In some embodiments of the present application, based on the above-mentioned scheme, the action rate determination unit 603 is also used to control the action rate of the throttle module to be the third rate, and the action rates of the negative pressure valve module and the supercharger module to be the first rate when the EGR operating condition is the fourth operating condition, the fifth operating condition, the seventh operating condition or the ninth operating condition; when the EGR operating condition is the sixth operating condition, the action rate of the throttle module is controlled to be the second rate, and the action rates of the negative pressure valve module and the supercharger module are both the third rate; when the EGR operating condition is the eighth operating condition, the action rates of the throttle module and the supercharger module are controlled to be the third rate, and the action rate of the negative pressure valve module is the second rate.

[0165] In some embodiments of the present application, based on the aforementioned scheme, the action rate determination unit 603 is also used to control the action rate of the EGR valve module to be the third rate multiplied by the knock correction coefficient when the EGR operating condition is the fifth operating condition; and to control the action rate of the EGR valve module to be the second rate multiplied by the knock correction coefficient when the EGR operating condition is the sixth operating condition or the seventh operating condition.

[0166] In some embodiments of the present application, based on the above-mentioned scheme, the action rate determination unit 603 is also used to control the action rate of the EGR valve module to be the first rate multiplied by the knock correction coefficient and the gas volume correction coefficient when the EGR operating condition is the fourth operating condition, the eighth operating condition or the ninth operating condition.

[0167] In some embodiments of the present application, based on the aforementioned solution, the action rate determination unit 603 is further configured to determine a knock correction coefficient according to the knock retreat angle of the engine and a preset mapping relationship.

[0168] In some embodiments of the present application, based on the aforementioned solution, the action rate determination unit 603 is further configured to determine an air volume correction coefficient according to the actual air intake volume of the engine and a preset formula.

[0169] Based on the same inventive concept, the embodiment of the present application also provides a control device for the intake air volume of an engine based on a low-pressure EGR system, referring to Figure 7 , shows a structural schematic diagram of the intake air quantity control device of the engine based on the low-pressure EGR system in an embodiment of the present application, the intake air quantity control device of the engine based on the low-pressure EGR system includes one or more memories 704, one or more processors 702 and at least one computer program (computer program instruction) stored on the memory 704 and executable on the processor 702, and the method described above is implemented when the processor 702 executes the computer program.

[0170] Among them, Figure 7 In the embodiment of the present invention, a bus architecture (represented by bus 700) is shown. Bus 700 may include any number of interconnected buses and bridges, and bus 700 links various circuits including one or more processors represented by processor 702 and memory represented by memory 704. Bus 700 may also link various other circuits such as peripherals, voltage regulators, and power management circuits, which are well known in the art and therefore will not be described further herein. Bus interface 705 provides an interface between bus 700 and receiver 701 and transmitter 703. Receiver 701 and transmitter 703 may be the same component, namely a transceiver, which provides a unit for communicating with various other devices over a transmission medium. Processor 702 is responsible for managing bus 700 and general processing, while memory 704 may be used to store data used by processor 702 when performing operations.

[0171] Based on the same inventive concept, an embodiment of the present application provides a computer-readable storage medium, in which computer program instructions are stored. When the computer program instructions are executed by a processor, the processor is prompted to implement the steps of the method as described above.

[0172] The functions described herein may be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, the functions may be stored as one or more instructions or codes on or transmitted via a computer-readable medium. Other examples and implementations are within the scope and spirit of this application and the appended claims. For example, due to the nature of software, the functions described above may be implemented using software executed by a processor, hardware, firmware, hardwiring, or a combination of any of these. Furthermore, the functional units may be integrated into a single processing unit, each unit may exist physically separately, or two or more units may be integrated into a single unit.

[0173] In the several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. Among them, the device embodiments described above are only exemplary. For example, the division of the units can be a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of units or modules, which can be electrical or other forms.

[0174] The units described as separate components may or may not be physically separate, and the components of the control device may or may not be physical units, that is, they may be located in one place or distributed across multiple units. Some or all of the units may be selected according to actual needs to achieve the purpose of the present embodiment.

[0175] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application is essentially or the part that contributes to the prior art or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions for enabling a computer device (which can be a personal computer, a server or a network device, etc.) to execute all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: U disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), mobile hard disk, magnetic disk or optical disk, etc. Various media that can store computer program instructions.

[0176] The foregoing is merely an embodiment of the present application and is not intended to limit the present application. Various modifications and variations are possible for those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present application shall be included within the scope of the claims of the present application.

Claims

1. A method for controlling the intake air volume of an engine based on a low-pressure EGR system, characterized in that: The low-pressure exhaust gas recirculation (EGR) system includes four modules: a throttle module, a negative pressure valve module, an EGR valve module, and a supercharger module. The control method includes: Determine the EGR operating conditions of the engine according to the operating parameters of the engine; Determine the action sequence of the four modules according to the EGR operating conditions; Determine the action rates of the four modules based on EGR operating conditions and preset rates; Control the execution sequence and speed of the four modules; The EGR operating conditions include the first to ninth operating conditions, the operating parameters include speed and load, and the control method further includes: The first operating condition is determined as the first operating condition, in which the first state is outside the EGR area and the second state is in a steady state; the second operating condition is determined as the second operating condition, in which the first state is inside the EGR area and the second state is in a steady state; the third operating condition is determined as the first operating condition, in which the first state is outside the EGR area and the second state is in a transient state; the fourth operating condition is determined as the first operating condition, in which the first state is inside the EGR area, the second state is in a transient state, and the rate of change of the speed and / or the rate of change of the load is less than a preset value; the fourth operating condition is determined as the first operating condition, in which the first state is inside the EGR area, the second state is in a transient state, and the rate of change of the speed and / or the rate of change of the load is greater than a preset value. The operating condition of the first state being switched from being in the EGR area to being outside the EGR area, the second state being in a transient state, and the load being reduced is determined as the sixth operating condition; the operating condition of the first state being switched from being in the EGR area to being outside the EGR area, the second state being in a transient state, and the load being increased is determined as the seventh operating condition; the operating condition of the first state being switched from being outside the EGR area to being in the EGR area, the second state being in a transient state, and the load being reduced is determined as the eighth operating condition; the operating condition of the first state being switched from being outside the EGR area to being in the EGR area, the second state being in a transient state, and the load being increased is determined as the ninth operating condition; When the EGR operating condition is the first operating condition or the second operating condition, the four modules are kept inactive; When the EGR operating condition is the third operating condition, the throttle module and the supercharger module are controlled to operate in sequence, and the negative pressure valve module and the EGR valve module are kept inactive; When the EGR operating condition is any one of the fourth to ninth operating conditions, the four modules are controlled to operate in sequence according to a preset order.

2. The control method according to claim 1, characterized in that: The engine's EGR operating conditions are determined based on the engine's operating parameters, including: determining a first state of the engine according to whether the speed and load meet the operating conditions of the low-pressure EGR system, wherein the first state includes being in the EGR zone or being outside the EGR zone; determining a second state of the engine according to whether the speed and the load change, wherein the second state includes being in a steady state or in a transient state; An EGR operating condition of the engine is determined according to the first state and the second state.

3. The control method according to claim 2, characterized in that: Determining a first state of the engine based on whether the speed and load meet the operating conditions of the low-pressure EGR system includes: When the speed and load meet the operating conditions of the low-pressure EGR system, determine that the engine is in the EGR zone; When the speed and load do not meet the operating conditions, it is determined that the engine is outside the EGR area.

4. The control method according to claim 2, characterized in that: Determine the second state of the engine based on whether the speed and load change, where the second state includes being in a steady state or in a transient state, including: determining that the engine is in a transient state when at least one of the speed and the load changes; The engine is determined to be in steady state when neither speed nor load changes.

5. The control method according to claim 1, characterized in that: When the EGR operating condition is any of the fourth to ninth operating conditions, the four modules are controlled to operate in sequence according to a preset order, including: When the EGR working condition is the fourth working condition, the negative pressure valve module, the EGR valve module, the throttle module and the supercharger module are controlled to operate in sequence; When the EGR working condition is the fifth working condition, the EGR valve module, the throttle module, the supercharger module and the negative pressure valve module are controlled to operate in sequence; When the EGR working condition is the sixth working condition, the throttle module, the EGR valve module, the supercharger module and the negative pressure valve module are controlled to operate in sequence; When the EGR working condition is the seventh working condition, the EGR valve module, the throttle module, the supercharger module and the negative pressure valve module are controlled to operate in sequence; When the EGR working condition is the eighth working condition, the negative pressure valve module, the supercharger module, the EGR valve module and the throttle module are controlled to operate in sequence; When the EGR operating condition is the ninth operating condition, the throttle module, the negative pressure valve module, the EGR valve module and the supercharger module are controlled to operate in sequence.

6. The control method according to claim 1, characterized in that: Also includes: Determine the air volume change rate based on the engine's required air volume and actual air volume; The action time intervals among the throttle module, the negative pressure valve module, the EGR valve module and the supercharger module are determined according to the air volume change rate, wherein the air volume change rate is negatively correlated with the action time interval.

7. The control method according to claim 1, characterized in that: The preset rates include a first rate, a second rate, or a third rate that increases in sequence. The action rates of the four modules are determined according to the EGR operating conditions and the preset rates, including: When the EGR operating condition is the first operating condition or the second operating condition, the action rates of the throttle module, the negative pressure valve module, the EGR valve module and the supercharger module are controlled to be zero; When the EGR operating condition is the third operating condition, the action rates of the throttle module and the supercharger module are controlled to be the second rate, and the action rates of the negative pressure valve module and the EGR valve module are controlled to be zero; When the EGR operating condition is the fourth operating condition, the fifth operating condition, the sixth operating condition, the seventh operating condition, the eighth operating condition or the ninth operating condition, the action rate of the throttle module, the negative pressure valve module and the supercharger module is controlled to be the preset rate, and the action rate of the EGR valve module is controlled to be the preset rate multiplied by the correction coefficient.

8. The control method according to claim 7, characterized in that: Control the action rate of the throttle module, negative pressure valve module and supercharger module to the preset rate, including: When the EGR operating condition is the fourth operating condition, the fifth operating condition, the seventh operating condition or the ninth operating condition, the action rate of the throttle module is controlled to be the third rate, and the action rates of the negative pressure valve module and the supercharger module are both controlled to be the first rate; When the EGR operating condition is the sixth operating condition, the action rate of the throttle module is controlled to be the second rate, and the action rates of the negative pressure valve module and the supercharger module are both controlled to be the third rate; When the EGR operating condition is the eighth operating condition, the action rates of the throttle module and the supercharger module are controlled to be the third rate, and the action rate of the negative pressure valve module is controlled to be the second rate.

9. The control method according to claim 7, characterized in that: The correction coefficient includes a knock correction coefficient, which controls the action rate of the EGR valve module to be a preset rate multiplied by the correction coefficient, including: When the EGR operating condition is the fifth operating condition, the action rate of the EGR valve module is controlled to be the third rate multiplied by the knock correction coefficient; When the EGR operating condition is the sixth operating condition or the seventh operating condition, the action rate of controlling the EGR valve module is the second rate multiplied by the knock correction coefficient.

10. The control method according to claim 7, characterized in that: The correction coefficients include the knock correction coefficient and the gas volume correction coefficient. The action rate of the EGR valve module is controlled by multiplying the preset rate by the correction coefficient, including: When the EGR operating condition is the fourth operating condition, the eighth operating condition, or the ninth operating condition, the action rate of controlling the EGR valve module is the first rate multiplied by the knock correction coefficient and the gas volume correction coefficient.

11. The control method according to claim 9 or 10, characterized in that: Also includes: The knock correction coefficient is determined based on the engine's knock recession angle and a preset mapping relationship.

12. The control method according to claim 10, characterized in that: Also includes: Determine the air volume correction coefficient based on the actual air intake volume of the engine and the preset formula.

13. A control device for the intake air quantity of an engine based on a low-pressure EGR system, characterized in that: The low-pressure exhaust gas recirculation (EGR) system consists of four modules: a throttle module, a negative pressure valve module, an EGR valve module, and a supercharger module. The control device includes: An EGR operating condition determination unit, configured to determine the EGR operating condition of the engine according to operating parameters of the engine; An action sequence determination unit, used to determine the action sequence of the four modules according to the EGR operating conditions; An action rate determination unit, used to determine the action rates of the four modules according to the EGR operating conditions and the preset rates; The action execution unit is used to control the action sequence and action rate of the four modules; Among them, the EGR operating conditions include the first to ninth operating conditions, and the operating parameters include speed and load. The EGR operating condition determination unit is also used to determine the operating condition in which the first state is outside the EGR area and the second state is in a steady state as the first operating condition; determine the operating condition in which the first state is in the EGR area and the second state is in a steady state as the second operating condition; determine the operating condition in which the first state is outside the EGR area and the second state is in a transient state as the third operating condition; determine the operating condition in which the first state is in the EGR area, the second state is in a transient state, and the rate of change of speed and / or load is less than a preset value as the fourth operating condition; determine the operating condition in which the first state is in the EGR area and the second state is in a transient state , and the rate of change of speed and / or the rate of change of load is greater than a preset value, which is determined as the fifth operating condition; the operating condition in which the first state is switched from being in the EGR area to being outside the EGR area, the second state is in a transient state, and the load is reduced is determined as the sixth operating condition; the operating condition in which the first state is switched from being in the EGR area to being outside the EGR area, the second state is in a transient state, and the load is increased is determined as the seventh operating condition; the operating condition in which the first state is switched from being outside the EGR area to being in the EGR area, the second state is in a transient state, and the load is reduced is determined as the eighth operating condition; the operating condition in which the first state is switched from being outside the EGR area to being in the EGR area, the second state is in a transient state, and the load is increased is determined as the ninth operating condition; The action sequence determination unit is also used to keep the four modules inactive when the EGR operating condition is the first operating condition or the second operating condition; to control the throttle module and the supercharger module to operate in sequence and keep the negative pressure valve module and the EGR valve module inactive when the EGR operating condition is the third operating condition; and to control the four modules to operate in sequence according to a preset order when the EGR operating condition is any one of the fourth to ninth operating conditions.

14. A device for controlling the intake air volume of an engine based on a low-pressure EGR system, comprising a processor and a memory, wherein: The memory stores computer program instructions that can be executed by the processor. When the processor executes the computer program instructions, the steps of the method according to any one of claims 1 to 12 are implemented.

15. A computer-readable storage medium, characterized in that The computer-readable storage medium stores computer program instructions, which, when executed by a processor, prompt the processor to implement the steps of the method according to any one of claims 1 to 12.

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