An EGR control method and related apparatus

Abstract

An EGR control method and related device relate to the technical field of engines, and a scheme comprises the following steps: firstly, judging whether the engine is in a high load region marked in advance; when the engine is in the high load region, obtaining a combustion chamber temperature and pressure; then, further obtaining knock sensitivity matched with the combustion chamber temperature and pressure based on a preset mapping relationship; then, adjusting a target P parameter in closed-loop proportional control based on the knock sensitivity and a load change rate; and finally, performing closed-loop control on the EGR based on the determined target P parameter. The target P parameter is directly related to the response rate of the closed-loop control, the greater the value of the target P parameter, the faster the response rate of the closed-loop control, the faster the response rate of the closed-loop control, the more timely the adjustment of the EGR opening degree, therefore, the faster the EGR opening degree is adjusted, the lower the engine knock probability, and therefore, the scheme can effectively reduce the engine knock probability under a high load working condition.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of engines, in particular to an EGR control method and related device. BACKGROUND

[0002] In the field of spark-ignition engines (such as natural gas engines, methanol engines, etc.), knock phenomenon is a very common and intractable problem. When the engine operates in the high load region, the temperature and pressure in the combustion chamber rise sharply, and the probability of knock also increases significantly. Once knock occurs, it is like a "civil unrest" that can seriously disrupt the normal operation of the engine, leading to a significant decline in engine performance, a significant reduction in service life, and an increase in harmful emissions, causing more serious pollution to the environment.

[0003] The traditional EGR (Exhaust Gas Recirculation) control method only uses one fixed control strategy. However, the working characteristics of the engine in different load regions are very different, and this "one-size-fits-all" control method is obviously difficult to adapt. Especially in the high load region, due to the lack of precise adaptation to the working condition characteristics, low-precision EGR control can easily cause instability in the combustion process, like adding weight to a building that is already on the verge of collapse, and may even further exacerbate the knock phenomenon, causing the engine to fall into a more dangerous situation.

[0004] Therefore, it is urgent to develop an EGR control strategy that can precisely exert force and effectively suppress the probability of knock in high load conditions. SUMMARY

[0005] Therefore, the embodiments of the present application provide an EGR control method and related device to reduce the probability of knock in high load conditions of the engine.

[0006] To achieve the above object, the embodiments of the present application provide the following technical solutions:

[0007] An EGR control method, comprising:

[0008] determining whether the engine is in a pre-labeled high load region;

[0009] when the engine is in the high load region, obtaining the temperature and pressure of the combustion chamber;

[0010] obtaining the knock sensitivity matched with the temperature and pressure of the combustion chamber based on a preset mapping relationship;

[0011] obtaining the load change rate of the engine;

[0012] adjusting the target P parameter in the closed-loop proportional control based on the knock sensitivity and the load change rate;

[0013] The EGR is closed-loop controlled based on a target P parameter.

[0014] Optionally, in the EGR control method, the EGR is closed-loop controlled based on a target P parameter, comprising:

[0015] A proportional control function is constructed based on the target P parameter;

[0016] A set EGR flow rate and an actual EGR flow rate are obtained;

[0017] The EGR is closed-loop P controlled based on the set EGR flow rate and the actual EGR flow rate by using the proportional control function, to obtain an EGR closed-loop opening degree;

[0018] An EGR feedforward opening degree matching the set EGR flow rate is obtained;

[0019] A sum of the EGR closed-loop opening degree and the EGR feedforward opening degree is taken as an EGR set opening degree;

[0020] The opening degree of the EGR valve is controlled based on the EGR set opening degree.

[0021] Optionally, in the EGR control method, the target P parameter in the closed-loop proportional control is adjusted based on the knock sensitivity and the load change rate, comprising:

[0022] A target P parameter in the closed-loop proportional control matching the magnitude of the knock sensitivity and the magnitude of the load change rate is obtained, wherein the greater the knock sensitivity and the load change rate, the greater the P parameter, and the smaller the knock sensitivity and the load change rate, the smaller the P parameter.

[0023] Optionally, in the EGR control method, the actual EGR flow rate is obtained, comprising:

[0024] The actual EGR flow rate is calculated by using an EGR valve model.

[0025] Optionally, in the EGR control method, when the engine is not in the high load region, the method further comprises:

[0026] The opening degree of the EGR valve is adjusted based on the working condition of the engine, wherein the working condition of the engine at least includes the engine speed and the engine intake amount.

[0027] Optionally, in the EGR control method, the determination of whether the engine is in the pre-labeled high load region comprises:

[0028] The load value of the engine is obtained;

[0029] When the load value of the engine is greater than a target load, it is determined that the engine is in the high load region.

[0030] determining that the engine is in a low load region when the load value of the engine is not greater than a target load.

[0031] Optionally, in the EGR control method, the combustion chamber temperature and pressure are obtained, comprising:

[0032] obtaining an engine load, an engine speed, an intake air temperature and a cooling water temperature;

[0033] calculating the combustion chamber temperature and pressure based on the engine load, the engine speed, the intake air temperature and the cooling water temperature by using a combustion chamber temperature and pressure model.

[0034] An EGR control device, comprising:

[0035] a load region identification unit configured to determine whether the engine is in a pre-labeled high load region;

[0036] a combustion chamber data calculation unit configured to obtain a combustion chamber temperature and pressure when the engine is in the high load region;

[0037] a knock sensitivity calculation unit configured to obtain a knock sensitivity matched with the combustion chamber temperature and pressure based on a pre-set mapping relationship;

[0038] a load change rate acquisition unit configured to obtain a load change rate of the engine;

[0039] a proportional control parameter configuration unit configured to adjust a target P parameter in closed-loop proportional control based on the knock sensitivity and the load change rate;

[0040] a closed-loop control unit configured to perform closed-loop control on the EGR based on the target P parameter.

[0041] An electronic device comprising at least one processing device and a storage device connected to the processing device, wherein:

[0042] the storage device is configured to store a computer program;

[0043] the processing device is configured to execute the computer program to enable the electronic device to implement the EGR control method as described in any one of the above.

[0044] An automobile comprising the electronic device as described above.

[0045] Based on the technical scheme, the scheme provided by the embodiment of the application first judges whether the engine is in a high load region previously calibrated; when the engine is in the high load region, the combustion chamber temperature and pressure are acquired; then the knock sensitivity matched with the combustion chamber temperature and pressure is further acquired based on a preset mapping relationship; then the target P parameter in the closed-loop proportional control is adjusted based on the knock sensitivity and the load change rate; finally, the EGR is controlled in a closed loop based on the determined target P parameter. The target P parameter is directly related to the response rate of the closed-loop control, the greater the value of the target P parameter, the faster the response rate of the closed-loop control, the faster the response rate of the closed-loop control, and the more timely the adjustment of the EGR opening degree. Therefore, the faster the EGR opening degree is adjusted, the lower the engine knock probability is. Therefore, the scheme can effectively reduce the engine knock probability in a high load working condition. BRIEF DESCRIPTION OF DRAWINGS

[0046] In order to more clearly illustrate the technical scheme in the embodiments of the application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced. Obviously, the drawings in the following description are only embodiments of the application, and other drawings can be obtained by those skilled in the art without creative labor on the basis of the provided drawings.

[0047] Figure 1 A flowchart of an EGR control method provided by an embodiment of the application;

[0048] Figure 2 A flowchart of a closed-loop control method of an EGR valve opening degree provided by an embodiment of the application;

[0049] Figure 3 A strategy diagram of the closed-loop control of the EGR valve opening degree;

[0050] Figure 4 A schematic diagram of the change trend of the set EGR flow and the actual EGR flow in the closed-loop control process;

[0051] Figure 5 A strategy diagram of the EGR control when the engine is in a low load region disclosed by the embodiment of the application;

[0052] Figure 6 A structure diagram of an EGR control device disclosed by the embodiment of the application;

[0053] Figure 7 A structure schematic diagram of an electronic device provided by the embodiment of the application. DETAILED DESCRIPTION

[0054] The technical solutions in the embodiments of the present application will be clearly and completely described with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative effort belong to the scope of protection of the present application.

[0055] First, the professional technical terms used in this application are explained:

[0056] Knock: Knock is an abnormal combustion phenomenon in the operation process of a spark-ignition engine, usually manifested as irregular explosive combustion, which causes the engine to vibrate, make noise, and may damage engine parts.

[0057] EGR: Exhaust Gas Recirculation, exhaust gas recirculation, the exhaust gas discharged by the engine is introduced into the intake pipe and mixed with fresh gas before entering the combustion chamber for combustion. The EGR system can dilute the combustible mixture and reduce the combustion temperature to suppress the occurrence of knock, so that the rapid and accurate control of EGR to the specified position is an important means of knock suppression.

[0058] ECU: Electronic Control Unit, electronic control unit.

[0059] In the prior art, the EGR control method usually adopts a fixed control strategy, such as the EGR closed-loop control method based on PID control. This kind of method adjusts according to the deviation between the set EGR target value and the actual EGR value during engine operation to realize EGR control. However, this kind of method has the following shortcomings:

[0060] In the high load area, due to the high combustion temperature and pressure, the knock sensitivity increases, and the traditional PID control method is difficult to quickly and accurately adjust the EGR rate, which makes it difficult to effectively suppress the knock phenomenon.

[0061] In the low load area, due to the low knock sensitivity, the traditional control method may over-adjust the EGR rate, resulting in a decrease in system stability, and even affecting the combustion efficiency of the engine.

[0062] The present application proposes a gas engine EGR control method based on load adaptation, which effectively suppresses the knock phenomenon in the high load area by using different EGR control strategies in the high load area and the low load area, while optimizing the combustion efficiency and emission performance of the engine.

[0063] Referring to Figure 1 The EGR control method disclosed in the embodiments of the present application comprises:

[0064] Step S101: judging whether the engine is in a pre-labeled high load region.

[0065] In this embodiment, the operating load of the engine is divided into a high load region and a low load region. Generally, the high load region refers to a region where the engine load exceeds a certain pre-set target load (for example, set to 70%, but this value can be flexibly adjusted according to the actual knock condition of the engine), and the low load region corresponds to the case where the engine load is lower than the target load.

[0066] In the specific operation steps, after obtaining the real-time load value of the engine, it is compared with the pre-set target load. If the load value is higher than the target load, it is determined that the engine is currently in a high load operating state; otherwise, if the load value does not exceed the target load, it is determined that the engine is in a low load operating region.

[0067] Step S102: when the engine is in the high load region, obtaining the combustion chamber temperature and pressure.

[0068] In this scheme, a dynamic model of the combustion chamber temperature and pressure changing with the parameters such as EGR rate, engine load, engine speed, intake temperature and cooling water temperature can be constructed by combining experiments and simulations, which is denoted as a combustion chamber temperature and pressure model. Then the combustion chamber temperature and pressure are calculated by using the pre-constructed combustion chamber temperature and pressure model, wherein the input data of the combustion chamber temperature and pressure model can include any one or a combination of multiple items of EGR rate, engine load, engine speed, intake temperature and cooling water temperature, and the output of the combustion chamber temperature and pressure model is the combustion chamber temperature and pressure.

[0069] Step S103: obtaining the knock sensitivity matched with the combustion chamber temperature and pressure based on a pre-set mapping relationship.

[0070] In this scheme, a relationship model between knock sensitivity and combustion chamber temperature and pressure can be constructed based on experimental data in advance, which is denoted as a knock sensitivity model. After the combustion chamber temperature and pressure are determined, the knock sensitivity is calculated based on the knock sensitivity model.

[0071] Step S104: obtaining the load change rate of the engine.

[0072] In this step, the load change rate of the engine is calculated based on the load change of the engine.

[0073] The engine load change rate refers to the change amount of the engine load per unit time, which reflects the speed of the change of the engine load with time, and is usually expressed in percentage per second (% / s). Its calculation formula is:

[0074] Load change rate = (current load value - previous load value) ÷ previous load value × 100% ÷ time interval.

[0075] Step S105: adjusting the target P parameter in the closed-loop proportional control based on the knock sensitivity and the load change rate;

[0076] In this solution, a mapping relationship between knock sensitivity and load change rate and the target P parameter in closed-loop proportional control can be established in advance. In this mapping relationship, the greater the knock sensitivity and the load change rate, the larger the P parameter, and the smaller the knock sensitivity and the load change rate, the smaller the P parameter. The target P parameter is the proportional control parameter in PID control.

[0077] Step S106: performing closed-loop control on the EGR based on the target P parameter.

[0078] The closed-loop control refers to PID closed-loop control, in which the size of the P parameter is directly related to the response rate of the closed-loop control. The larger the value of the P parameter, the faster the response speed of the closed-loop control, and vice versa, the slower the response speed of the closed-loop control. Therefore, the present application configures corresponding target P parameters for the closed-loop control under high-load conditions, thereby improving the response rate of the closed-loop control under high-load conditions. The faster the closed-loop control response, the lower the probability of engine knock.

[0079] See also Figure 2 In this embodiment, the closed-loop control of the EGR is performed based on the target P parameter, including:

[0080] Step S201: constructing a proportional control function based on the target P parameter.

[0081] After the target P parameter is determined, a proportional control function in PID control is constructed based on the target P parameter.

[0082] Step S202: Acquire the set EGR flow rate and the actual EGR flow rate.

[0083] In this step, the actual EGR flow rate E needs to be obtained act , the actual EGR flow E act It can be calculated by the EGR valve physical model. The input of the EGR valve physical model includes the actual EGR opening and at least one of the pressure and temperature parameters before and after the EGR valve. The output of the EGR valve physical model is the actual EGR flow rate E act .

[0084] Specifically, the EGR valve physical model is: ;

[0085] Wherein the formula is:

[0086] M is the flow rate through the EGR valve, i.e. the actual EGR flow rate;

[0087] Ac max is the maximum flow area of the EGR valve, which is calibrated according to the specific situation;

[0088] rA is the proportion curve of the maximum flow area corresponding to each EGR opening degree r, which is specifically obtained by calibration.

[0089] P us and T us are the pressure and temperature upstream of the EGR valve.

[0090] is the flow function, which is a function of P us and P ds , P ds is the pressure downstream of the EGR valve.

[0091] The set EGR flow rate is an EGR flow rate set based on engine operating conditions, including engine speed and engine intake air quantity, i.e. the set EGR flow rate is calculated based on engine speed and engine intake air quantity.

[0092] Step S203: using the proportional control function to perform closed-loop P control based on the set EGR flow rate and the actual EGR flow rate to obtain an EGR closed-loop opening degree;

[0093] After obtaining the set EGR flow rate and the actual EGR flow rate, closed-loop P control is performed based on the deviation between the two, i.e. referring to Figure 3 , the deviation between the set EGR flow rate and the actual EGR flow rate is denoted as E dvt , a P controller is used to perform closed-loop P control based on E dvt and a target P parameter to obtain an EGR closed-loop opening degree matching the E dvt .

[0094] In an engine control system, using a closed-loop P control strategy to calculate an EGR closed-loop opening degree based on the deviation between a set EGR flow rate and an actual EGR flow rate is a key link to ensure accurate control of the EGR system. Closed-loop P control, i.e. proportional control, is a basic link in PID control. The core idea is to amplify the deviation between the set value (set EGR flow rate) and the actual value (actual EGR flow rate) through a proportional coefficient, so as to adjust the control quantity (EGR closed-loop opening degree) to make the actual value approach the set value as soon as possible.

[0095] The target P parameter in the P controller can be calibrated and queried according to the load change rate parameter and the knock sensitivity parameter to more reasonably monitor and control the knock. As shown in Table 1, the horizontal axis represents the load change rate parameter and the vertical axis represents the knock sensitivity parameter. This solution calibrates the target parameter P based on these two parameters. If the load change rate is large and the knock sensitivity is high, the target P parameter can be calibrated slightly larger (for example, calibrated to 4), which can adjust the EGR more quickly and reduce the knock behavior ( Figure 4 The short-dashed line represents the actual EGR flow following curve with a larger target P parameter calibration, and the long-dashed line represents the actual EGR flow following curve with a smaller P parameter calibration).

[0096]

[0097] Table 1

[0098] Step S204: obtaining an EGR feedforward opening that matches the set EGR flow rate;

[0099] In this step, the EGR feedforward opening corresponds to the set EGR flow. After determining the set EGR flow, the EGR feedforward opening can be determined based on the corresponding relationship. In this solution, the relationship between the two can be stored in the EGR valve inverse model. The input of the EGR valve inverse model is the set EGR flow, and the output is the EGR feedforward opening.

[0100] The EGR valve model and the EGR valve inverse model are completely inverse to each other. Since the EGR valve model and the inverse model are completely inverse to each other, the EGR flow rate E is set under the steady state of the engine. des and the actual EGR flow E act are completely equal, and there is only a deviation E between the two in the transient process dvt .like Figure 4 Compared with traditional PID closed-loop control, this solution can reduce EGR overshoot during transient processes. Furthermore, because the valve physical model has higher accuracy in the high-load region (due to the larger EGR flow rate in this region, the calculation accuracy is higher than in the low-load region), this solution can achieve fast and accurate EGR regulation, reducing knock in this high-load region.

[0101] Step S205: taking the sum of the EGR closed-loop opening and the EGR feedforward opening as the EGR set opening;

[0102] In this step, after the EGR closed-loop opening and the EGR feedforward opening are calculated, the sum of the EGR feedforward opening and the EGR closed-loop opening is used as the final required EGR opening of this application, that is, the EGR set opening.

[0103] Step S206: controlling the opening degree of the EGR valve based on the EGR set opening degree.

[0104] In this step, the EGR valve position closed loop module is used to control the actual opening degree of the EGR valve based on the EGR set opening degree. According to the basic principle of closed loop control, there is a transient deviation between the EGR set opening degree and the actual opening degree. Because the physical existence of the transient deviation between the EGR valve set opening degree and the actual opening degree leads to a transient deviation between the set EGR flow and the actual EGR flow. The model-based closed loop control method can quickly and accurately adjust the EGR valve to the predetermined position in the high load region, thereby effectively suppressing the generation of knock.

[0105] When the engine is in the low load region, the response speed and control accuracy of the EGR control can be appropriately reduced, and the control strategy can be simplified to improve the stability of the entire engine system, because the possibility of knock occurring in the engine in this region is relatively low. At this time, the open loop control method is used to control the opening degree of the EGR valve, that is, the opening degree of the EGR valve is directly adjusted based on the working condition of the engine (for example: speed and air volume), as shown in Figure 5 After the engine speed and engine intake volume are obtained, the base opening degree matched with the engine speed and engine intake volume is determined based on the base opening degree MAP, the opening degree change rate is determined based on the engine speed, and the base opening degree is corrected based on the opening degree change rate to obtain the EGR control opening degree. By adjusting the base opening degree by using the opening degree change rate, the opening degree change of the EGR can be made more gentle, and the stability of the entire system can be improved.

[0106] An EGR control device is also disclosed in the embodiment. The specific working content of each unit in the device is described in the above method embodiment.

[0107] The EGR control device provided in the embodiment of the application is described below. The EGR control device described below can be referred to in correspondence with the EGR control method described above.

[0108] Referring to Figure 6 , the EGR control device can include:

[0109] A load region identification unit 10 is configured to determine whether the engine is in a pre-labeled high load region.

[0110] A combustion chamber data calculation unit 20 is configured to obtain the combustion chamber temperature and pressure when the engine is in the high load region.

[0111] A knock sensitivity calculation unit 30 is configured to obtain the knock sensitivity matched with the combustion chamber temperature and pressure based on a pre-set mapping relationship.

[0112] The load change rate acquisition unit 40 is configured to acquire a load change rate of the engine.

[0113] The proportional control parameter configuration unit 50 is configured to adjust a target P parameter in the closed-loop proportional control based on the knock sensitivity and the load change rate.

[0114] The closed-loop control unit 60 is configured to perform closed-loop control on the EGR based on the target P parameter.

[0115] In the above scheme, first, the load region identification unit 10 is used to determine whether the engine is in a pre-labeled high load region; when the engine is in the high load region, the combustion chamber data calculation unit 20 is used to acquire the combustion chamber temperature and pressure; then the knock sensitivity calculation unit 30 is further used to acquire the knock sensitivity matched with the combustion chamber temperature and pressure based on a pre-set mapping relationship; then the proportional control parameter configuration unit 50 is used to adjust the target P parameter in the closed-loop proportional control based on the knock sensitivity and the load change rate, and finally the closed-loop control unit 60 is used to perform closed-loop control on the EGR based on the determined target P parameter. The target P parameter is directly related to the response rate of the closed-loop control. The greater the value of the target P parameter, the faster the response rate of the closed-loop control. The faster the response rate of the closed-loop control, the more timely the adjustment of the EGR opening degree. Therefore, the faster the EGR opening degree is adjusted, the lower the engine knock probability is. Therefore, the scheme can effectively reduce the engine knock probability under high load conditions.

[0116] Corresponding to the above method, the present application also discloses an electronic device, which can include at least one processing device and a storage device connected to the processing device, wherein: the storage device is used to store a computer program; the processing device is used to execute the computer program, so that the electronic device can implement the EGR control method as described in any one of the above.

[0117] Reference Figure 7 The electronic device in the embodiments of the present application can include but is not limited to fixed terminals such as ECU (Electronic Control Unit), VCU (Vehicle Control Unit), MCU (Micro Controller Unit), HCU (Hybrid Control Unit) and the like. Figure 7 The electronic device shown is only an example and should not bring any limitation to the functions and use range of the embodiments of the present application.

[0118] As Figure 7As shown, the electronic device can include a processing device (e.g., a central processor, a graphics processor, etc.) 601 that can perform various appropriate actions and processes according to programs stored in a read only memory (ROM) 602 or loaded into a random access memory (RAM) 603 from a storage device 608. In a state where the electronic device is powered on, various programs and data required for operation of the electronic device are also stored in the RAM 603. The processing device 601, the ROM 602, and the RAM 603 are connected to each other through a bus 604. An input / output (I / O) interface 605 is also connected to the bus 604.

[0119] Generally, the following devices can be connected to the I / O interface 605: input devices 606 including, for example, a touch screen, a touch pad, a keyboard, a mouse, a camera, a microphone, an accelerometer, a gyroscope, etc.; output devices 607 including, for example, a liquid crystal display (LCD), a speaker, a vibrator, etc.; storage devices 608 including, for example, a memory card, a hard disk, etc.; and communication devices 609. The communication devices 609 can allow the electronic device to communicate wirelessly or wiredly with other devices to exchange data. Although Figure 7 An electronic device having various devices is shown, but it should be understood that all of the shown devices are not required to be implemented or possessed. More or fewer devices can be alternatively implemented or possessed.

[0120] The embodiments of the present application also provide a computer program product including computer readable instructions, which, when executed on an electronic device, cause the electronic device to implement any of the EGR control methods provided by the embodiments of the present application.

[0121] The embodiments of the present application also provide a computer readable storage medium carrying one or more computer programs, which, when executed by an electronic device, can cause the electronic device to implement any of the EGR control methods provided by the embodiments of the present application.

[0122] A car including the electronic device described above, which can be a fuel car, a gas car, or a hybrid car, and the car model can be any car model, for example, an engineering car (truck, excavator, dumper), a family car (sedan, SUV, business car), etc.

[0123] For the convenience of description, the above system is described in various modules according to functions. Of course, the functions of each module can be implemented in the same or more software and / or hardware when implementing the present application.

[0124] The various embodiments described in this specification are described in progressive order of complexity, from the simplest embodiment to more complex embodiments. Embodiments discussed in later paragraphs of this specification can apply to some, none, or all of the embodiments described in previous paragraphs. Different embodiments can be implemented only for particular instances of the various embodiments. Each of the various embodiments can be used independently and for that reason many repetitive elements of the various embodiments will not be repeated for the sake of brevity. The same or similar elements in the various embodiments are referred to by the same reference numerals. It is to be understood that the various embodiments described herein are merely exemplary in nature and that numerous changes to the embodiments described herein can be made without departing from the scope of the application. It is to be understood that the phraseology and terminology used herein is for the purpose of description and not of limitation. Any terminology consistent with the technical field of the application, or one of skill in the art, is intended to be interpreted by those skilled in the art in the context of the relevant art and the technical features disclosed herein.

[0125] Those skilled in the art will further appreciate that the units and algorithms described in connection with the examples disclosed herein can be embodied in electronic hardware, computer software, or combinations of both. To clearly illustrate this interchangeability of hardware and software, various examples disclosed herein have been described generally in terms of their functionality, without reference to the corresponding

[0126] The steps of a method or algorithm described in connection with the examples disclosed herein can be embodied directly in hardware, in a software module executed by a processor, or in a combination of the two. A software module can reside in random access memory (RAM), flash memory, read-only memory (ROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), registers, hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art. An exemplary storage medium is tangible.

[0127] It is also to be understood that the terminology and phraseology employed herein are for the purpose of description and should not be regarded as limiting. The use of "including" and "comprising" and variations thereof is meant to encompass the items listed thereafter and equivalents thereof as well as additional items and equivalents thereof. Further, the terms "a" and "an" are defined as one or more unless explicitly stated otherwise, and the terms "first" and "second" are not intended to denote a temporal sequence but to denote a classification.

[0128] The foregoing description of the disclosed embodiments enables a person skilled in the art to make or use the application. Numerous modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein can be applied to other embodiments without the use of the inventive faculty. Therefore, the present application is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An EGR control method characterized by, The method comprises: determining whether the engine is in a pre-labeled high load area; when the engine is in the high load area, obtaining the combustion chamber temperature and pressure; obtaining the knock sensitivity matched with the combustion chamber temperature and pressure based on a preset mapping relationship; obtaining the load change rate of the engine; adjusting the target P parameter in the closed-loop proportional control based on the knock sensitivity and the load change rate; performing closed-loop control on the EGR based on the target P parameter; performing closed-loop control on the EGR based on the target P parameter, comprising: constructing a proportional control function based on the target P parameter; obtaining the set EGR flow and the actual EGR flow; performing closed-loop P control based on the set EGR flow and the actual EGR flow by using the proportional control function to obtain the EGR closed-loop opening degree; obtaining the EGR feedforward opening degree matched with the set EGR flow; taking the sum of the EGR closed-loop opening degree and the EGR feedforward opening degree as the EGR set opening degree; controlling the opening degree of the EGR valve based on the EGR set opening degree; adjusting the target P parameter in the closed-loop proportional control based on the knock sensitivity and the load change rate, comprising: obtaining the target P parameter in the closed-loop proportional control matched with the size of the knock sensitivity and the size of the load change rate, wherein the larger the knock sensitivity and the load change rate are, the larger the P parameter is, and the smaller the knock sensitivity and the load change rate are, the smaller the P parameter is.

2. The EGR control method according to claim 1, characterized by, obtaining the actual EGR flow, comprising: calculating the actual EGR flow by using an EGR valve model.

3. The EGR control method according to claim 1, characterized by, when the engine is not in the high load area, the method further comprises: adjusting the EGR valve opening degree based on the working condition of the engine, wherein the working condition of the engine at least comprises the engine speed and the engine intake amount.

4. The EGR control method according to claim 1, characterized by, determining whether the engine is in a pre-labeled high load area, comprising: obtaining the load value of the engine; when the load value of the engine is greater than the target load, determining that the engine is in the high load area; when the load value of the engine is not greater than the target load, determining that the engine is in the low load area.

5. The EGR control method according to claim 1, characterized by, obtaining the combustion chamber temperature and pressure, comprising: obtaining the engine load, the engine speed, the intake temperature and the cooling water temperature; calculating the combustion chamber temperature and pressure based on the engine load, the engine speed, the intake temperature and the cooling water temperature by using a combustion chamber temperature and pressure model.

6. An EGR control device characterized by comprising: comprising: a load area identification unit for determining whether the engine is in a pre-labeled high load area; a combustion chamber data calculation unit for obtaining the combustion chamber temperature and pressure when the engine is in the high load area; a knock sensitivity calculation unit for obtaining the knock sensitivity matched with the combustion chamber temperature and pressure based on a preset mapping relationship; a load change rate acquisition unit for obtaining the load change rate of the engine; a proportional control parameter configuration unit for adjusting the target P parameter in the closed-loop proportional control based on the knock sensitivity and the load change rate; a closed-loop control unit for performing closed-loop control on the EGR based on the target P parameter; wherein performing closed-loop control on the EGR based on the target P parameter comprises: constructing a proportional control function based on the target P parameter; obtaining the set EGR flow and the actual EGR flow; performing closed-loop P control based on the set EGR flow and the actual EGR flow by using the proportional control function to obtain the EGR closed-loop opening degree; obtaining the EGR feedforward opening degree matched with the set EGR flow; taking the sum of the EGR closed-loop opening degree and the EGR feedforward opening degree as the EGR set opening degree; controlling the opening degree of the EGR valve based on the EGR set opening degree; construct a proportional control function based on the target P parameter; obtain a set EGR flow and an actual EGR flow; perform closed-loop P control based on the set EGR flow and the actual EGR flow using the proportional control function to obtain an EGR closed-loop opening degree; obtain an EGR feedforward opening degree matched with the set EGR flow; sum the EGR closed-loop opening degree and the EGR feedforward opening degree as an EGR set opening degree; control the opening degree of an EGR valve based on the EGR set opening degree; and adjust the target P parameter in the closed-loop proportional control based on the knock sensitivity and the load change rate, including: obtain a target P parameter in the closed-loop proportional control matched with the magnitude of the knock sensitivity and the magnitude of the load change rate, wherein the greater the knock sensitivity and the load change rate, the greater the P parameter, and the smaller the knock sensitivity and the load change rate, the smaller the P parameter.

7. An electronic device, comprising: comprise at least one processing device and a storage device connected to the processing device, wherein: the storage device is configured to store a computer program; the processing device is configured to execute the computer program to enable the electronic device to implement the EGR control method according to any one of claims 1 to 5.

8. An automobile characterized by comprising: the electronic device according to claim 7.

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