Multi-cylinder engine, control method and motor vehicle

Abstract

The disclosure provides a multi-cylinder engine, a control method and a motor vehicle, and relates to the technical field of engines, and the multi-cylinder engine comprises a monolithic cylinder head and a plurality of cylinders and a first regulating valve. Each cylinder is provided with an independent intake passage and an exhaust passage. The monolithic cylinder head is integrated with a common EGR passage and a first branch corresponding to each cylinder for connecting the intake passage of the cylinder and the common EGR passage. The first regulating valve is arranged in the first branch corresponding to the corresponding cylinder. The opening degree of each first regulating valve is configured to be related to the valve timing of the corresponding cylinder and the actual operating parameter of the multi-cylinder engine, so that the combustion state of each cylinder is consistent in the manner of single-cylinder EGR regulation. The design of the monolithic cylinder head of the multi-cylinder engine integrates the common EGR passage and the first branch, and the first regulating valve arranged in the first branch realizes single-cylinder EGR rate control, thereby realizing the consistency of the combustion state of each cylinder.

Description

TECHNICAL FIELD

[0001] The present disclosure belongs to the technical field of engines, and particularly relates to a multi-cylinder engine, a control method and a motor vehicle. BACKGROUND

[0002] Exhaust gas recirculation (EGR) has a significant impact on the combustion temperature in the cylinder of an engine. As the EGR rate increases, the transient maximum temperature and the average temperature in the cylinder decrease. Since a high-temperature environment is a necessary condition for the generation of nitrogen oxides, the increase in the EGR rate helps to reduce the emission of nitrogen oxides. However, the increase in the EGR rate means that the amount of fresh air entering the cylinder decreases, which leads to deterioration of the in-cylinder combustion condition, reduction of economy and increase of soot emission.

[0003] In the related art, a scheme for reducing the emission of nitrogen oxides in an engine is to introduce part of the exhaust gas before the turbine into the exhaust pipe, pass it through an EGR valve into the intake passage, and then mix it with fresh air before entering each cylinder again. In actual application, due to various factors such as machining tolerances, component fitting errors and fuel injector atomization in the engine, there are obvious differences in the working conditions of each cylinder when this scheme is applied. When the EGR rate of the intake manifold is high, the cylinders with obvious differences in working conditions have phenomena such as combustion deterioration, insufficient combustion and sudden increase of particulate matter emission due to the excessively high EGR rate compared with other cylinders. SUMMARY

[0004] The present disclosure provides a multi-cylinder engine, a control method and a motor vehicle, aiming to at least partially solve the technical problem that part of the cylinders is prone to combustion deterioration due to the inability to individually adjust the combustion state of each cylinder in the related art.

[0005] At least one embodiment of the present disclosure provides a multi-cylinder engine, comprising:

[0006] a plurality of cylinders, each of which is provided with an independent intake passage and an exhaust passage;

[0007] a monolithic cylinder head integrated with a common EGR passage and a first branch corresponding to each of the cylinders for connecting the intake passage and the common EGR passage; and

[0008] a plurality of first regulating valves, each of which is arranged in the first branch corresponding to the corresponding cylinder;

[0009] wherein the opening degree of each of the first regulating valves is configured to be related to the valve timing of the corresponding cylinder and the actual operating parameters of the multi-cylinder engine, so as to make the combustion state of each of the cylinders consistent in a single-cylinder EGR regulation manner.

[0010] In the multi-cylinder engine provided by at least one embodiment of the present disclosure, the integrated cylinder head further integrates a second branch for connecting the exhaust passage of each of the cylinders to the common EGR passage, and the multi-cylinder engine further comprises:

[0011] a plurality of second regulating valves, each of which is arranged in the second branch corresponding to a respective cylinder;

[0012] wherein the opening degree of each of the second regulating valves is configured to be related to the valve timing of the respective cylinder and the actual operating parameter of the multi-cylinder engine, so as to make the exhaust state of each of the cylinders consistent in a single-cylinder EGR regulation manner.

[0013] In the multi-cylinder engine provided by at least one embodiment of the present disclosure, the integrated cylinder head further integrates the intake passage and the exhaust passage of each of the cylinders and the intake valve and the exhaust valve of each of the cylinders, and the intake valve is arranged at the outlet of the intake passage of the respective cylinder, and the exhaust valve is arranged at the inlet of the exhaust passage of the respective cylinder.

[0014] The multi-cylinder engine provided by at least one embodiment of the present disclosure further comprises:

[0015] a controller configured to control the action of each of the first regulating valves.

[0016] In the multi-cylinder engine provided by at least one embodiment of the present disclosure, the common EGR passage is in a ring topology and arranged around the plurality of cylinders, or the common EGR passage is in a tree topology and arranged on one side of the plurality of cylinders, and the multi-cylinder engine further comprises:

[0017] a controller configured to control the action of each of the first regulating valves and each of the second regulating valves.

[0018] At least one embodiment of the present disclosure further provides a method for controlling a multi-cylinder engine, comprising:

[0019] In a multi-cylinder engine comprising a plurality of cylinders, an integrated cylinder head, and a plurality of first regulating valves, the valve timing of each of the cylinders and the actual operating parameter of the multi-cylinder engine are obtained; and,

[0020] for each of the cylinders, the opening degree of the first regulating valve corresponding to the cylinder is adjusted based on the valve timing of the cylinder and the actual operating parameter of the multi-cylinder engine, so as to make the combustion state of each of the cylinders consistent in a single-cylinder EGR regulation manner.

[0021] The method provided by at least one embodiment of the present disclosure further comprises:

[0022] In the multi-cylinder engine comprising a plurality of second adjusting valves, for each cylinder, the opening degree of the second adjusting valve corresponding to the cylinder is adjusted based on the valve timing of the cylinder and the actual operating parameter of the multi-cylinder engine, so as to make the exhaust state of each cylinder consistent in a single-cylinder EGR regulation manner.

[0023] In the method provided in at least one embodiment of the present disclosure, the valve timing comprises an ignition advance angle and an overlap angle, the actual operating parameter comprises an engine speed, an engine fuel injection amount, an engine intake amount and an engine exhaust gas circulation amount, and the adjusting the opening degree of the first adjusting valve corresponding to the cylinder based on the valve timing of the cylinder and the actual operating parameter of the multi-cylinder engine comprises:

[0024] generating an EGR rate set value of the cylinder based on the engine intake amount or the engine exhaust gas circulation amount, wherein the EGR rate set value of each cylinder is the same;

[0025] obtaining an EGR flow set value of the cylinder based on the EGR rate of the cylinder;

[0026] obtaining a control logic of the first adjusting valve corresponding to the cylinder, generating an EGR flow actual value of the cylinder based on the engine intake amount, the engine fuel injection amount and the control logic;

[0027] generating an opening degree feedforward value of the first adjusting valve based on the EGR flow set value and the engine speed; and,

[0028] obtaining a deviation between the EGR flow set value and the EGR flow actual value, and performing a PID control with feedforward on the opening degree of the first adjusting valve based on the deviation and the opening degree feedforward value, so as to make the combustion state of each cylinder consistent by adjusting the EGR rate of the cylinder.

[0029] In the method provided in at least one embodiment of the present disclosure, the EGR rate set value is positively correlated with the EGR flow set value, and the generating the EGR rate set value of the cylinder based on the engine intake amount or the engine exhaust gas circulation amount comprises:

[0030] inputting the engine intake amount and the engine exhaust gas circulation amount into a pre-set EGR rate set value generation model to obtain the EGR rate set value of the cylinder, wherein the EGR rate set value generation model is configured to generate the EGR rate set value based on the engine intake amount and the engine exhaust gas circulation amount.

[0031] In the method provided by at least one embodiment of the present disclosure, the control logic is intake-exhaust stroke-based control logic, and the control logic is configured to include:

[0032] The first adjusting valve and the second adjusting valve corresponding to different cylinder pairs in which an exhaust stroke and an intake stroke overlap each other are both opened in the overlap time to achieve single-cylinder EGR regulation.

[0033] The method provided by at least one embodiment of the present disclosure further includes: for each of the cylinders, obtaining an IQA code of an oil injector in the cylinder, and adjusting a drive waveform of the first adjusting valve and the second adjusting valve based on the IQA code; and

[0034] The EGR flow actual value of the cylinder is generated based on the engine intake amount, the engine fuel injection amount, and the control logic, including:

[0035] The engine intake amount and the engine fuel injection amount are input into a pre-set excess air coefficient generation model to obtain an excess air coefficient, wherein the excess air coefficient generation model is configured to generate the excess air coefficient based on the engine intake amount and the engine fuel injection amount;

[0036] The overlap angle and the ignition advance angle of the cylinder in the current working cycle are obtained based on the control logic;

[0037] The number of cylinders of the multi-cylinder engine is obtained, and the opening and closing state and the opening time of the first adjusting valve corresponding to the cylinder are generated based on the overlap angle, the ignition advance angle, and the number of cylinders; and

[0038] The EGR flow actual value is generated based on the excess air coefficient and the opening and closing state and the opening time of the first adjusting valve.

[0039] At least one embodiment of the present disclosure further provides a motor vehicle, which includes the multi-cylinder engine provided by any one of the embodiments of the present disclosure.

[0040] Compared with the related art, the multi-cylinder engine, the control method and the motor vehicle provided by the embodiments of the present disclosure can accurately control the operation of each cylinder. From the perspective of structure, the multi-cylinder engine particularly adds a first branch as an auxiliary passage in the intake passage of each cylinder of the integrated cylinder head, the intake end of the first branch is connected to the common EGR passage inside the integrated cylinder head, and the first branch is provided with a first adjusting valve for controlling the on-off of the first branch and the size of the EGR exhaust flow. The multi-cylinder engine has a simple structure and relatively lower manufacturing and maintenance costs. From the perspective of control mode, by accurately adjusting the opening size of each first adjusting valve and using the flow characteristics of the common EGR passage and the first branch, the exhaust gas of each cylinder can be effectively utilized and finely adjusted and controlled. In this way, the overall efficiency of the exhaust system is improved, and each cylinder can achieve the best emission state and performance during the operation process, ensuring the uniformity of the operation of each cylinder and solving the technical problem that part of the cylinders are prone to combustion deterioration due to the inability to individually adjust the combustion state of each cylinder in the related art.

[0041] It should be understood that the foregoing general description and the following detailed description are only exemplary and explanatory, and cannot limit the present disclosure. BRIEF DESCRIPTION OF DRAWINGS

[0042] In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure, the drawings needed in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present disclosure, and other drawings can be obtained by those skilled in the art without creative labor.

[0043] Figure 1 A composition schematic diagram of a multi-cylinder engine provided for at least one embodiment of the present disclosure;

[0044] Figure 2 A composition schematic diagram of a multi-cylinder engine provided for at least one embodiment of the present disclosure; Figure 1 A cross-sectional schematic diagram of an integrated cylinder head in the multi-cylinder engine;

[0045] Figure 3 A composition schematic diagram of another multi-cylinder engine provided for at least one embodiment of the present disclosure;

[0046] Figure 4 A composition schematic diagram of another multi-cylinder engine provided for at least one embodiment of the present disclosure; Figure 3 A cross-sectional schematic diagram of an integrated cylinder head in the multi-cylinder engine;

[0047] Figure 5 A composition schematic diagram of another multi-cylinder engine provided for at least one embodiment of the present disclosure;

[0048] Figure 6 A flowchart of a method for controlling a multi-cylinder engine provided for at least one embodiment of the present disclosure;

[0049] Figure 7 A schematic diagram of an operating cycle of a six-cylinder in-line engine according to at least one embodiment of the present disclosure;

[0050] Figure 8 A flow chart of an example of a method of controlling a multi-cylinder engine according to at least one embodiment of the present disclosure;

[0051] Figure 9 A block diagram of a motor vehicle according to at least one embodiment of the present disclosure.

[0052] Reference Signs

[0053] 1 - cylinder; 2 - monoblock cylinder head; 3 - first regulating valve; 4 - second regulating valve; 5 - intake valve; 6 - exhaust valve; 7 - controller; 8 - external exhaust pipe; 11 - intake passage; 12 - exhaust passage; 21 - common EGR passage; 22 - first branch; 23 - second branch; 100 - motor vehicle; 101 - multi-cylinder engine. DETAILED DESCRIPTION

[0054] The present disclosure will be further described by way of illustration with reference to the accompanying drawings and embodiments. It is specifically intended that the embodiments are illustrative of the present disclosure, but are not limiting thereof. Likewise, it is intended that the present disclosure encompass all alternatives, modifications and equivalents falling within the scope of the appended claims. It will be apparent to those skilled in the art that numerous and various embodiments can be derived from the teachings of the present disclosure without departing from the scope of the present disclosure.

[0055] The terms "first", "second" and "third" are used only for descriptive purposes and are not to be construed as indicating or implying relative importance or a quantity of the indicated technical features. Thus, a feature defined with "first", "second" and "third" can include at least one of the features.

[0056] In the description of the present disclosure, the meaning of "a plurality of" is at least two, such as two or three, unless otherwise specifically defined.

[0057] In this disclosure, the terms “one embodiment”, “some embodiments”, “an example”, “a specific example” or “some examples” etc. mean that a particular feature, structure, material or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the disclosure. The illustrative representations of the above terms in this specification do not necessarily refer to the same embodiment or example. Moreover, the particular features, structures, materials or characteristics described can be combined in any suitable manner in one or more embodiments or examples. In addition, different embodiments or examples described in this specification and the features of different embodiments or examples can be combined and combined by those skilled in the art without contradiction, if necessary.

[0058] The terms “include” and “have” and any variations thereof in the embodiments of the disclosure are intended to cover non-exclusive inclusion. For example, a process, a multi-cylinder engine, a system, a product or an apparatus including a series of steps or units is not limited to the listed steps or units, but can optionally include steps or units not listed, or can optionally include other steps or components inherent to the process, the multi-cylinder engine, the product or the apparatus.

[0059] The term “exhaust gas recirculation”, abbreviated as EGR, in the embodiments of the disclosure refers to the re-introduction of a portion of the exhaust gas discharged from the engine into the intake system, which is mixed with fresh air and then enters the cylinder again to participate in combustion. This technology aims to reduce the combustion temperature, reduce the emission of nitrogen oxides, and improve the fuel economy and performance of the engine.

[0060] The term “EGR rate” in the embodiments of the disclosure refers to the exhaust gas recirculation rate, i.e. the proportion of EGR exhaust gas that is re-introduced into the intake system, mixed with fresh air and participates in combustion.

[0061] The term “ignition advance angle” in the embodiments of the disclosure refers to the angle of the piston from the top dead center when the spark plug ignites the mixture in the cylinder.

[0062] The term “overlap angle” in the embodiments of the disclosure refers to the range of crankshaft rotation when the intake valve and the exhaust valve of the cylinder are opened at the same time.

[0063] The term “top dead center”, abbreviated as TDC, in the embodiments of the disclosure refers to the state when the piston moves to its highest position in the cylinder. In the working cycle of a multi-cylinder engine, TDC is a key time point, which marks the end of the compression stroke and the beginning of the power stroke in the cylinder.

[0064] The term "injection correction code" in the embodiments of the present disclosure, referred to as IQA code, contains the deviation information of the actual injection amount of the injector from the nominal value. Through the code, the output oil amount of the injector in the cylinder can be finely adjusted to adapt to various engine operating conditions and fuel characteristics, thereby improving the performance and fuel economy of the engine.

[0065] The related art has the technical problem that the combustion state of each cylinder cannot be adjusted individually, resulting in combustion deterioration in some cylinders. After the combustion deteriorates, the particulate matter in the EGR exhaust gas flowing into the intake pipe (also referred to as the intake passage) can cause pollution to the heating grid component, thereby triggering abnormal conditions, and even possibly causing damage to the engine. Moreover, as the EGR rate increases, the ignition timing of some cylinders is continuously delayed, the flame propagation rate after ignition is slowed down, the in-cylinder pressure and maximum explosion pressure are significantly reduced, the time to reach the peak pressure is delayed, the peak value of the heat release rate is reduced, and the overall heat release rate curve is shifted backward, resulting in continuous deterioration of the combustion state in the cylinder.

[0066] To solve the above technical problems, the present disclosure provides a multi-cylinder engine that can precisely control the combustion state of each cylinder. A common EGR passage is provided in the integrated cylinder head, a first branch is provided between the common EGR passage and the intake passage of each cylinder, and a first regulating valve is installed on the first branch. By controlling the opening degree of the first regulating valve, the precise control effect of the combustion state of each cylinder is achieved, thereby ensuring that the working states of the cylinders are consistent.

[0067] Figure 1 A schematic diagram of a multi-cylinder engine according to at least one embodiment of the present disclosure is provided. As shown in Figure 1 , the multi-cylinder engine can include a plurality of cylinders 1, an integrated cylinder head 2, and a plurality of first regulating valves 3.

[0068] Each cylinder 1 is provided with an independent intake passage 11 and an exhaust passage 12.

[0069] The integrated cylinder head 2 integrates a common EGR passage 21 and a first branch 22 corresponding to each cylinder 1 for connecting its intake passage 11 and the common EGR passage 21. Figure 1 (not shown in the figure), see Figure 2 ).

[0070] Each first regulating valve 3 is arranged in the first branch 22 corresponding to the corresponding cylinder 1.

[0071] Each first regulating valve 3 is arranged in the first branch 22 corresponding to the corresponding cylinder 1.

[0072] It should be noted that each cylinder 1 corresponds to at least one first regulating valve 3. The present disclosure does not limit the setting position of the intake passage 11 and the exhaust passage 12 and the driving type of the first regulating valve 3. For example, the intake passage 11 and the exhaust passage 12 can be integrated in the monolithic cylinder head 2 as shown in Figure 1 , or be set in other positions.

[0073] In the above scheme, the cross section of the monolithic cylinder head 2 is shown in Figure 2 . Based on Figure 1 , Figure 2 , the connection relationship between the common EGR passage 21 and the intake passage 11 of each cylinder 1 can be more clearly seen. The first branch 22 branches from the common EGR passage 21 and leads to the intake passage 11 of each cylinder 1. The first regulating valve 3 for adjusting the actual value of the EGR rate of the corresponding cylinder 1 is arranged on the first branch 22. This design enables the EGR gas to be uniformly and accurately distributed to each cylinder 1, thereby ensuring that the working states of the cylinders 1 are consistent. In addition, the structure of the monolithic cylinder head 2 is relatively compact, reducing the number of components and assembly complexity, and improving the reliability and durability of the engine.

[0074] In the above scheme, the consistency of the combustion state of each cylinder 1 can be determined by various measures, and the embodiments of the present disclosure do not limit this. For example, a cylinder pressure measuring device is installed in each cylinder 1 to obtain a cylinder pressure curve, the combustion pressure curve is measured in real time, and the consistency of the combustion state of the multiple cylinders 1 is determined by comparing parameters such as peak pressure, pressure rise rate, and combustion phase. For another example, the instantaneous speed fluctuation of the corresponding cylinder 1 is detected by using a crankshaft speed sensor, and if the combustion of a certain cylinder is weak, the speed of the working stroke of the cylinder will be less improved. Based on this, the consistency of the combustion state of the multiple cylinders 1 is determined. For another example, a vibration acceleration sensor is installed in each cylinder 1, and when the combustion of a certain cylinder is weak, the vibration energy of the corresponding frequency band is low. Based on this, the consistency of the combustion state of the multiple cylinders 1 is determined. In actual application, appropriate determination methods can be selected according to specific needs.

[0075] In implementation, the opening of each first regulating valve 3 can be controlled and adjusted based on the valve timing of the corresponding cylinder 1 and the actual operating parameters of the multi-cylinder engine, so that the combustion state of each cylinder 1 is adjusted based on the differences between the cylinders 1, and then the combustion state of each cylinder 1 is consistent.

[0076] Some embodiments of the present disclosure also provide a control method corresponding to the above multi-cylinder engine and a motor vehicle.

[0077] The multi-cylinder engine provided by at least one embodiment of the present disclosure is suitable for any application scenario of the multi-cylinder engine, and embodiments of the present disclosure do not limit the application scenario. For example, the multi-cylinder engine can be applied to various devices requiring power output, such as cars, trucks, buses, ships, and generator sets. In these application scenarios, the engine generates power by burning fuel to drive the vehicle or device to run. Through the multi-cylinder engine provided by the embodiment of the present disclosure, the combustion states of the plurality of cylinders 1 are consistent by precisely controlling the combustion state of each cylinder 1, thereby improving the stability of the engine, reducing emissions, and optimizing fuel economy. In addition, the design of the integrated cylinder head 2 integrates the common EGR passage 21 and the first branch passage 22, optimizes the structure of the engine, reduces the manufacturing cost, and is beneficial to the later maintenance and maintenance.

[0078] Compared with the related art, the present disclosure provides a multi-cylinder engine that can precisely control the operation of each cylinder 1. From the structural point of view, the multi-cylinder engine specially adds the first branch passage 22 as an auxiliary passage in the intake passage 11 of each cylinder 1 of the integrated cylinder head 2, the intake end of the first branch passage 22 is connected to the common EGR passage 21 inside the integrated cylinder head 2, and the first branch passage 22 is provided with the first regulating valve 3 for controlling the on-off of the first branch passage 22 and the size of the EGR exhaust flow. The multi-cylinder engine has a simple structure and relatively lower manufacturing and maintenance costs. From the perspective of control mode, by precisely adjusting the opening size of each first regulating valve 3 and using the flow characteristics of the common EGR passage 21 and the first branch passage 22, the exhaust gas of each cylinder 1 can be effectively utilized and finely adjusted and controlled. In this way, not only the overall efficiency of the exhaust system is improved, but also each cylinder 1 can achieve the best emission state and performance during the working process, ensuring the uniformity of the work of each cylinder 1 and solving the technical problem that part of the cylinders 1 are prone to combustion deterioration due to the inability to individually adjust the combustion state of each cylinder 1 in the related art.

[0079] Each cylinder 1 has the main function of providing power output and participating in the combustion process. The cylinder 1 realizes the four strokes of fuel suction, compression, combustion, and exhaust gas emission through the reciprocating motion of the internal piston and the opening and closing of the intake valve and the exhaust valve. In this process, the cylinder 1 not only drives the crankshaft to rotate to provide power output, but also cooperates with other cylinders 1 by precisely controlling the EGR rate to ensure the consistency of the combustion state of the entire engine to improve the stability, reduce the emissions, and optimize the fuel economy.

[0080] The main function of the integrated cylinder head 2 is to integrate the EGR system of the engine, and can also integrate the intake system and exhaust system of the engine. The integrated cylinder head 2 connects the common EGR passage 21 and the intake passage 11 and the exhaust passage 12 of each cylinder 1 through its unique design, realizing the compactness of the engine structure. This design not only reduces the number of engine parts and reduces manufacturing costs, but also improves the reliability and durability of the engine. At the same time, the integrated design of the integrated cylinder head 2 also facilitates later maintenance and maintenance, reducing the use cost.

[0081] The main function of the first regulating valve 3 is to accurately regulate the flow of EGR exhaust gas entering the corresponding cylinder. By accurately controlling the opening and closing time of the first regulating valve 3 and the opening degree, the accurate metering of the EGR exhaust gas can be realized, so as to ensure that the EGR rate can meet the needs of the engine under different working conditions. This fine control helps to further optimize the combustion process of the engine, reduce the emission of harmful substances such as nitrogen oxides, and at the same time maintain the power and economy of the engine.

[0082] Figure 3 Another schematic diagram of a multi-cylinder engine is provided for at least one embodiment of the present disclosure. Based on Figure 1 , as shown in Figure 3 , in order to realize the separate control of the exhaust gas of each cylinder, the integrated cylinder head 2 also integrates the second branch 23 corresponding to each cylinder 1 for connecting the exhaust passage 12 and the common EGR passage 21 of each cylinder 1, and the multi-cylinder engine also includes a plurality of second regulating valves 4, each second regulating valve 4 is arranged in the second branch 23 corresponding to the corresponding cylinder 1. The opening degree of each second regulating valve 4 is configured to be related to the valve timing of the corresponding cylinder 1 and the actual operating parameters of the multi-cylinder engine, so as to make the exhaust state of each cylinder 1 consistent through single-cylinder EGR regulation.

[0083] Among them, the main function of the second regulating valve 4 is to regulate the EGR flow of each cylinder 1 to the common EGR passage 21, to ensure that the EGR flow of each cylinder 1 can be flexibly adjusted according to the real-time working condition and valve timing of the engine. The scheme adds a second branch 23 in the exhaust passage 12 of each cylinder 1 of the integrated cylinder head 2, the exhaust end of the second branch 23 is connected with the common EGR passage 21, and a second regulating valve 4 is arranged on the second branch 23, so that the exhaust utilization and accurate adjustment between each cylinder 1 can be effectively realized. This design not only optimizes the overall performance of the exhaust system, but also improves the working efficiency and environmental protection performance of the engine, and ensures the stability and controllability of the exhaust process. By accurately controlling the opening degree of the second regulating valve 4, compared with Figures 1-2The scheme can further optimize the combustion efficiency of the engine, balance the exhaust states of the cylinders 1, reduce the generation of emissions, and improve the overall performance and stability of the engine. The first regulating valve 3 and the second regulating valve 4 of each cylinder 1 are controlled, and the common EGR gas passage is used to achieve accurate regulation of the EGR rate and exhaust utilization between the cylinders 1.

[0084] In some embodiments, in order to achieve accurate control of the cylinder exhaust, the consistency of the exhaust state of each cylinder 1 includes but is not limited to judging by the following measures: real-time monitoring and recording of key parameters such as exhaust temperature, exhaust pressure and exhaust flow of each cylinder 1; by comparing and analyzing the change trend and numerical range of these parameters, it can be preliminarily evaluated whether the exhaust state of each cylinder 1 is consistent, wherein when the exhaust parameters of all cylinders 1 are stable within the preset reasonable range and the difference between them is within the minimum allowable limit, it can be judged that the exhaust state of the multiple cylinders 1 is consistent.

[0085] Figure 3 In the scheme, the cross section of the integrated cylinder head 2 is as shown in Figure 4 On the basis of Figure 3 , as shown in Figure 4 , in order to simplify the structure, the integrated cylinder head 2 also integrates the intake valve 5 and the exhaust valve 6 of each cylinder 1, the intake valve 5 is arranged at the outlet of the intake passage of the corresponding cylinder 1, and the exhaust valve 6 is arranged at the inlet of the exhaust passage of the corresponding cylinder 1. Among them, this design not only further simplifies the structure of the engine and reduces the number of parts, but also improves the overall performance and reliability of the engine. At the same time, the integrated intake valve 5 and exhaust valve 6 also facilitate later maintenance and replacement, reducing the use cost. In addition, by accurately controlling the opening and closing time of the intake valve 5 and the exhaust valve 6, the combustion process of the engine can be further optimized, the fuel economy can be improved, and the emissions can be reduced.

[0086] Figure 5 Another composition schematic diagram of a multi-cylinder engine is provided for at least one embodiment of the present disclosure. On the basis of Figure 1 , as shown in Figure 5 , in order to facilitate later maintenance, the multi-cylinder engine further includes a plurality of external exhaust pipes 8, wherein one end of each external exhaust pipe 8 is connected to the exhaust passage 12 of the corresponding cylinder 1 of the integrated cylinder head 2, and the other end of each external exhaust pipe 8 is connected to the common EGR passage 21 of the integrated cylinder head 2. Among them, this design makes the exhaust of each cylinder 1 can be separately led out and collected into the common EGR passage 21 through the external exhaust pipe 8. The design of the external exhaust pipe 8 helps the later maintenance and repair, reduces the use cost, and improves the reliability and durability of the engine.

[0087] As shown in Figure 5As shown, in order to achieve the control of the combustion state of each cylinder 1, the multi-cylinder engine further comprises a controller 7 for controlling the action of each first regulating valve 3. Moreover, the controller 7 is configured to the steps of the following method embodiment, which will not be repeated here.

[0088] In some embodiments, in order to achieve the dual control of the combustion state and the exhaust state of each cylinder 1, the controller 7 is used to control the action of each first regulating valve 3 and each second regulating valve 4. Moreover, the controller 7 is configured to the steps of the following method embodiment, which will not be repeated here.

[0089] In some embodiments, in order to enhance the exhaust flow smoothness of the engine, the common EGR passage 21 is of a ring topology and is arranged around the plurality of cylinders 1. Among them, the common EGR passage 21 of such a ring topology is designed so that the exhaust gas can be more evenly distributed to each cylinder 1, further improving the combustion efficiency and fuel economy of the engine. At the same time, the ring topology also helps to reduce the pressure loss in the exhaust system, thereby enhancing the exhaust flow smoothness of the engine. In addition, such a design also makes the common EGR passage 21 more compact, saving space for the engine, and helps to improve the power density and overall performance of the engine.

[0090] In some embodiments, in order to optimize the exhaust distribution strategy, the common EGR passage 21 is of a tree topology and is arranged on one side of the plurality of cylinders 1, as shown in Figure 5 Among them, the common EGR passage 21 of such a tree topology is designed so that the exhaust gas can be more flexibly distributed to each cylinder 1, and accurately regulated according to the working requirements of different cylinders 1. This design optimizes the exhaust distribution strategy, which helps to further improve the combustion efficiency and fuel economy of the engine. At the same time, the tree topology also has good scalability, which provides convenience for future possible engine upgrades or improvements. In addition, arranging the common EGR passage 21 on one side of the plurality of cylinders 1 helps to simplify the layout of the exhaust system, reduce manufacturing difficulty and cost, and also facilitate the later maintenance and repair work.

[0091] Figure 6 A flowchart of a method for controlling a multi-cylinder engine is provided for at least one embodiment of the present disclosure. The method can be applied to a multi-cylinder engine including but not limited to Figures 1-5 As shown, and the method is a balanced control method. As shown, the method can include the following steps S10-S20. Figure 6

[0092] Step S10: Obtain the valve timing of each cylinder 1 in the multi-cylinder engine and the actual operating parameters of the multi-cylinder engine.

[0093] ​Step S20: For each cylinder 1, adjust the opening of the first regulating valve 3 based on the valve timing of the cylinder 1 and the actual operating parameters of the multi-cylinder engine, so as to make the combustion state of each cylinder 1 consistent in a single-cylinder EGR control manner.

[0094] Wherein, through real-time monitoring and analysis of the valve timing of each cylinder 1 in the multi-cylinder engine and the actual operating parameters of the multi-cylinder engine, the controller 7 can accurately determine whether the combustion state of each cylinder 1 is consistent, and then take corresponding adjustment measures. In step S20, the controller 7 controls the opening of the corresponding first regulating valve 3 according to the valve timing of each cylinder 1 and the actual operating parameters, so as to ensure that each cylinder 1 can obtain an appropriate amount of EGR flow, thereby achieving the purposes of optimizing the combustion state, improving the engine performance and reducing the emissions. In addition, compared with the multi-cylinder engine control scheme shown in Figure 3 and Figure 4 The multi-cylinder engine control scheme shown in Figure 1 and Figure 2 The multi-cylinder engine control scheme shown in

[0095] In some embodiments, in order to realize the consistency of the exhaust state of each cylinder, the method can further include the following step S30.

[0096] Step S30: For each cylinder 1, adjust the opening of the second regulating valve 4 corresponding to the cylinder 1 based on the valve timing of the cylinder 1 and the actual operating parameters of the multi-cylinder engine, so as to make the exhaust state of each cylinder 1 consistent in a single-cylinder EGR control manner.

[0097] Wherein, through further analysis of the valve timing of each cylinder 1 in the multi-cylinder engine and the actual operating parameters, the controller 7 can more finely control the exhaust state of each cylinder 1. In step S30, in addition to the first regulating valve 3, the controller 7 also controls the opening of the corresponding second regulating valve 4 according to the valve timing of each cylinder 1 and the actual operating parameters. This step aims to ensure that each cylinder 1 can maintain consistent exhaust pressure, temperature and flow during the exhaust process, thereby further optimizing the combustion efficiency and emission performance of the engine. By comprehensively adjusting the openings of the first regulating valve 3 and the second regulating valve 4, the method can realize the overall optimization of the combustion and exhaust processes of the multi-cylinder engine.

[0098] In some embodiments, in order to further comprehensively optimize the combustion and exhaust process of each cylinder 1, the valve timing of the cylinder 1 includes the ignition advance angle (also referred to as the TDC-based advance angle) and the overlap angle of the cylinder, and the actual operating parameters of the multi-cylinder engine include the engine speed, the engine fuel injection amount, the engine intake amount, and the engine exhaust gas circulation amount. Among them, the engine speed, the engine fuel injection amount, the engine intake amount, and the engine exhaust gas circulation amount are important parameters reflecting the operating state of the engine. By monitoring these parameters and adjusting the opening degree of the first adjusting valve 3 based on these parameters, the EGR rate of each cylinder 1 can be further optimized, so that the combustion state of each cylinder 1 is more consistent, thereby improving the overall performance and environmental performance of the engine.

[0099] In some embodiments, in order to further improve the response speed and stability of the method, step S20 is refined to include the following sub-steps S201-S205.

[0100] Sub-step S201: generating the EGR rate set value of the cylinder 1 based on the engine intake amount or the engine exhaust gas circulation amount, wherein the EGR rate set value of each cylinder 1 is the same.

[0101] Sub-step S202: obtaining the EGR flow set value of the cylinder 1 based on the EGR rate of the cylinder 1.

[0102] Sub-step S203: obtaining the control logic of the first adjusting valve 3 corresponding to the cylinder 1, and generating the EGR flow actual value of the cylinder 1 based on the engine intake amount, the engine fuel injection amount, and the control logic.

[0103] Sub-step S204: generating the opening degree feedforward value of the first adjusting valve 3 based on the EGR flow set value and the engine speed corresponding to the cylinder 1.

[0104] Sub-step S205: obtaining the deviation between the EGR flow set value and the EGR flow actual value, and performing PID control on the opening degree of the first adjusting valve 3 corresponding to the cylinder 1 with feedforward based on the deviation and the opening degree feedforward value, so as to make the combustion state of each cylinder 1 consistent by adjusting the EGR rate of the cylinder 1.

[0105] It should be noted that the PID control with feedforward is an advanced control strategy commonly used in the field, which combines feedforward control and PID control. The feedforward control preliminarily adjusts the opening of the first regulating valve 3 through the pre-set opening feedforward value, so as to quickly respond to the change of the EGR flow set value; and the PID control finely adjusts based on the deviation between the EGR flow set value and the actual value, so as to ensure that the opening of the first regulating valve 3 can accurately reach the target value, thereby realizing accurate control of the EGR rate of the cylinder 1. The PID control includes proportional control, integral control and differential control. The proportional control is used to adjust the opening of the first regulating valve 3 corresponding to the cylinder 1 according to the deviation, the integral control is used to eliminate the cumulative effect of the deviation, and the differential control is used to predict the trend of the deviation and adjust the opening of the first regulating valve 3 corresponding to the cylinder 1 in advance.

[0106] Through the scheme of sub-steps S201-S205, the EGR rate of each cylinder 1 can be accurately controlled, and the emission consistency of each cylinder 1 can be ensured. This control strategy combining feedforward and PID not only improves the response speed of the EGR system, but also effectively reduces the overshoot and steady-state error, so that the combustion state of each cylinder 1 is more consistent, thereby improving the overall performance and stability of the engine.

[0107] In some embodiments, in order to balance fuel performance and emissions, sub-step S201 is refined to include: inputting the engine intake amount and the engine exhaust gas circulation amount into a pre-set EGR rate set value generation model to obtain the EGR rate set value of the cylinder 1. The EGR rate set value generation model is configured to generate the EGR rate set value corresponding to the cylinder 1 based on the engine intake amount and the engine exhaust gas circulation amount. The EGR rate set value generation model can use an advanced algorithm, which comprehensively considers the influence of the engine intake amount and the engine exhaust gas circulation amount on the EGR rate. Through a large amount of experimental data and analysis of engine operating characteristics, the model can accurately predict the EGR rate set value that achieves the best combustion effect and emission performance under different intake amounts and engine exhaust gas circulation amounts. The implementation of this refinement step not only improves the accuracy of EGR rate control, but also helps the engine to maintain stable performance and low emissions under different working conditions.

[0108] In some embodiments, in order to facilitate implementation, the EGR rate set value generation model is configured as:

[0109] EGR rate set value = (engine exhaust gas circulation amount) / (engine intake amount + engine exhaust gas circulation amount),

[0110] Wherein, the engine exhaust gas circulation amount refers to the amount of exhaust gas entering the cylinder 1 through the first adjusting valve 3, which can be accurately measured or estimated by parameters such as the opening degree of the EGR valve and the exhaust gas pressure. The engine intake amount refers to the amount of fresh air entering the cylinder 1, which can also be measured in real time by sensors such as air flow meters. Through the above formula, the EGR rate set value under the current working condition can be quickly and accurately calculated, thereby providing a reliable basis for subsequent EGR control. This calculation method is simple and intuitive, easy to implement, and can fully consider the influence of engine exhaust gas circulation amount and engine intake amount on EGR rate, thereby ensuring the accuracy and effectiveness of EGR control.

[0111] In some embodiments, in sub-step S202, the EGR rate set value is positively correlated with the EGR flow set value. Wherein, the higher the EGR rate set value, the greater the required EGR flow set value, to ensure sufficient exhaust gas recirculation amount to achieve the expected combustion effect. This positive correlation is based on the operating characteristics and combustion requirements of the engine, aiming to optimize the emission performance and fuel economy of the engine. By accurately controlling the EGR flow set value, accurate adjustment of the EGR rate can be achieved, thereby further improving the combustion state and overall performance of the engine.

[0112] In some embodiments, the control logic of sub-step S203 is based on the intake and exhaust stroke control logic, and the control logic is configured to include opening both the first adjusting valve 3 and the second adjusting valve 4 corresponding to different cylinders 1 with overlapping exhaust and intake strokes within the overlap time, to realize single-cylinder EGR regulation. Wherein, the first adjusting valve 3 corresponding to the cylinder 1 is arranged on the exhaust manifold of the cylinder 1 in the exhaust stroke, for adjusting the exhaust gas pressure in the exhaust manifold; the second adjusting valve 4 corresponding to the cylinder 1 is arranged on the intake manifold of the cylinder 1 in the intake stroke, for adjusting the air flow in the intake manifold. During the period of mutual overlap of the exhaust and intake strokes, by simultaneously opening the first adjusting valve 3 and the second adjusting valve 4, part of the exhaust gas in the cylinder 1 in the exhaust stroke can be mixed with fresh air through the opened second adjusting valve 4, common EGR passage 21, first adjusting valve 3, and then enter the cylinder 1 in the intake stroke. This control method can flexibly adjust the exhaust and intake states of the cylinder 1, thereby realizing accurate control of the EGR rate and further optimizing the combustion efficiency and emission performance of the engine.

[0113] The following describes the intake and exhaust stroke-based control logic of the present disclosure taking a six-cylinder in-line engine as an example.

[0114] Figure 7 The working cycle diagram of the six-cylinder in-line engine provided in at least one embodiment of the present disclosure is shown in FIG. 1. The relationship between the crankshaft angle (i.e., engine rotation angle) and the working cycle of each cylinder is shown in FIG. 2.Figure 6 As shown, the engine rotates clockwise, and the firing order is A cylinder - E cylinder - C cylinder - F cylinder - B cylinder - D cylinder. There is an overlap relationship between the exhaust stroke of each cylinder and the intake stroke of other cylinders, which is shown in Table 1.

[0115] Table 1

[0116]

[0117] According to this overlap relationship, in the 180° crank angle interval corresponding to the exhaust stroke of each cylinder, there is an angle range of 120° that overlaps with the intake strokes of the other two cylinders. Moreover, in the middle section of the exhaust stroke (an angle range of about 60°), the cylinder is completely overlapped with the other two cylinders in the intake state. Due to the existence of the overlap angle, the actual intake and exhaust angles are greater than 180°, and therefore the overlap range is also greater than 60°. The above is the introduction of the stroke theory.

[0118] The above embodiments of the present disclosure control the opening of the first regulating valve 3 and the second regulating valve 4 corresponding to different cylinders in the above completely overlapped overlap time, that is, the single-cylinder EGR control effect can be achieved.

[0119] In some embodiments, in order to improve the control accuracy, the first regulating valve 3 and the second regulating valve 4 are both electric regulating valves. The electric regulating valve has the advantages of fast response speed, high control accuracy, easy integration into the engine control system, etc. Through the electric driving mode, accurate control of the first regulating valve 3 and the second regulating valve 4 can be realized, so as to ensure that the first regulating valve 3 and the second regulating valve 4 can be opened synchronously and accurately in the time period when the exhaust stroke and the intake stroke overlap with each other, so as to meet the flexible adjustment requirements of the cylinder exhaust state and the intake state. In addition, the electric regulating valve also has a long service life and a low maintenance cost, which helps to improve the reliability and economy of the entire engine system.

[0120] In some embodiments, the driving waveform of the first regulating valve 3 and the second regulating valve 4 is configured to be related to the IQA code of the fuel injector in the corresponding cylinder. By associating the driving waveform of the first regulating valve 3 and the second regulating valve 4 with the IQA code of the fuel injector in the corresponding cylinder, more precise adjustment of the engine intake state and exhaust state can be realized. Specifically, according to the working condition of the engine and the IQA code of the fuel injector, the required EGR rate can be calculated, and the opening time and opening degree of the first regulating valve 3 and the second regulating valve 4 are adjusted accordingly, so as to ensure that the engine can maintain the best combustion efficiency and emission performance under different loads, speeds and emission requirements. This control method not only improves the flexibility of the engine, but also further improves the fuel economy and environmental performance of the engine.

[0121] In some embodiments, to more accurately obtain the actual EGR flow value of each cylinder 1 of the multi-cylinder engine under different operating conditions, the generation method of sub-step S203 can be further refined into the following sub-steps S203a-S203d.

[0122] Sub-step S203a: input the engine intake volume and engine fuel injection volume into the pre-set excess air coefficient generation model to obtain the excess air coefficient, wherein the excess air coefficient generation model is configured to generate the excess air coefficient based on the engine intake volume and the engine fuel injection volume.

[0123] Sub-step S203b: obtain the overlap angle and the ignition advance angle of the cylinder 1 in the current working cycle based on the above control logic.

[0124] Sub-step S203c: obtain the number of cylinders of the multi-cylinder engine, and based on the overlap angle, the ignition advance angle and the number of cylinders, generate the opening and closing state and the opening time of the first regulating valve 3 corresponding to the cylinder 1.

[0125] Sub-step S203d: generate the actual EGR flow value of the cylinder 1 based on the excess air coefficient and the opening and closing state and the opening time of the first regulating valve 3 corresponding to the cylinder 1.

[0126] Wherein, the generation process of the actual EGR flow value of the cylinder 1 takes into account the real-time operating conditions of the engine, ensuring accurate control of the EGR system. By comprehensively considering the excess air coefficient, the opening and closing state and the opening time of the first regulating valve 3, the EGR flow can be dynamically adjusted to meet the needs of the engine under different operating conditions. This refined control method not only optimizes the combustion process of the engine, but also further reduces emissions and improves the overall performance of the engine.

[0127] In some embodiments, the excess air coefficient generation model is configured as:

[0128] Excess air coefficient = (engine intake volume) / (air volume required by engine fuel injection volume),

[0129] Wherein, the engine intake volume is the data obtained by real-time monitoring through intake manifold pressure sensor and air flow meter, etc. These data reflect the amount of air inhaled by the engine at a certain time. The air volume required by the engine fuel injection volume is the theoretical value calculated according to the engine fuel injection strategy, fuel properties and combustion requirements under the current operating conditions. By comparing the two values, the excess air coefficient can be obtained, which reflects the richness of air in the engine combustion chamber and is one of the important indicators for evaluating the combustion efficiency and emission performance of the engine. In the process of controlling the multi-cylinder engine, accurate calculation of the excess air coefficient is of great significance to optimize the combustion process, reduce emissions and improve the performance of the engine.

[0130] Figure 8 A flow chart of an example of a method for controlling a multi-cylinder engine is provided for at least one embodiment of the present disclosure. As shown in Figure 8 , the method includes the following:

[0131] a) EGR rate set value calculation based on engine speed, engine intake air amount, and engine exhaust gas circulation amount;

[0132] b) Excess air coefficient calculation based on engine speed, engine intake air amount, and engine fuel injection amount;

[0133] c) First adjusting valve 3 (or second adjusting valve 4) opening and closing state and opening time calculation based on engine speed and each cylinder 1 overlap angle, ignition advance angle, and cylinder number;

[0134] d) EGR flow set value calculation based on the EGR rate set value obtained in a);

[0135] e) EGR flow actual value calculation based on the excess air coefficient obtained in b) and the first adjusting valve 3 opening and closing state and opening time obtained in c);

[0136] f) Deviation calculation between the EGR flow set value and the EGR flow actual value for PID control;

[0137] g) Opening degree feedforward value acquisition according to the EGR flow set value and engine speed from the multi-cylinder engine working MAP;

[0138] h) First adjusting valve 3 (or second adjusting valve 4) adjustment to a certain reasonable range through pre-calibrated P parameter, I parameter, and D parameter according to the deviation obtained in f) and the opening degree feedforward value obtained in g).

[0139] Figure 9 A structural block diagram of a motor vehicle is provided for at least one embodiment of the present disclosure. As shown in Figure 9 , the motor vehicle 100 includes a multi-cylinder engine 101 as described in the above embodiments.

[0140] Although the embodiments of the present disclosure have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present disclosure, and those of ordinary skill in the art can make changes, modifications, replacements, and variations to the above embodiments within the scope of the present disclosure.

Claims

1. A multi-cylinder engine, characterized by, The method comprises: a plurality of cylinders (1), each of which is provided with an independent intake passage (11) and an exhaust passage (12); a monolithic cylinder head (2) integrated with a common EGR passage (21) and a first branch (22) corresponding to each of the cylinders (1) for connecting its intake passage (11) and the common EGR passage (21); a plurality of first regulating valves (3), each of which is arranged in the first branch (22) corresponding to the corresponding cylinder (1); and a controller (7) for controlling the action of each of the first regulating valves (3); wherein the controller (7) is configured to: obtain the valve timing of each cylinder (1) and the actual operating parameters of the multi-cylinder engine, wherein the actual operating parameters include engine speed, engine fuel injection amount, engine intake amount and engine exhaust gas recirculation amount; for each of the cylinders (1), generate an EGR rate set value of the cylinder (1) based on the engine intake amount or the engine exhaust gas recirculation amount, wherein the EGR rate set value of each of the cylinders (1) is the same; obtain the EGR flow set value of the cylinder (1) based on the EGR rate of the cylinder (1); obtain the control logic of the first regulating valve (3) corresponding to the cylinder (1), generate the EGR flow actual value of the cylinder (1) based on the engine intake amount, the engine fuel injection amount and the control logic; generate an opening degree feedforward value of the first regulating valve (3) based on the EGR flow set value and the engine speed; and obtain the deviation between the EGR flow set value and the EGR flow actual value, and perform PID control on the opening degree of the first regulating valve (3) with feedforward based on the deviation and the opening degree feedforward value, so as to make the combustion state of each of the cylinders (1) consistent by adjusting the EGR rate of the cylinder (1).

2. The multi-cylinder engine according to claim 1, characterized by, The monolithic cylinder head (2) is also integrated with a second branch (23) corresponding to each of the cylinders (1) for connecting its exhaust passage (12) and the common EGR passage (21), and the multi-cylinder engine further comprises: a plurality of second regulating valves (4), each of which is arranged in the second branch (23) corresponding to the corresponding cylinder (1); wherein the opening degree of each of the second regulating valves (4) is configured to be related to the valve timing of the corresponding cylinder (1) and the actual operating parameters of the multi-cylinder engine, so as to make the exhaust state of each of the cylinders (1) consistent in the manner of single-cylinder EGR regulation.

3. The multi-cylinder engine according to claim 1 or 2, characterized by, The monolithic cylinder head (2) is also integrated with the intake passage (11) and the exhaust passage (12) of each of the cylinders (1) and the intake valve (5) and the exhaust valve (6) of each of the cylinders (1), and the intake valve (5) is arranged at the outlet of the intake passage (11) of the corresponding cylinder (1), and the exhaust valve (6) is arranged at the inlet of the exhaust passage of the corresponding cylinder (1).

4. The multi-cylinder engine of claim 2, wherein The common EGR passage (21) is arranged in a ring topology and surrounds the plurality of cylinders (1), or the common EGR passage (21) is arranged in a tree topology and is arranged on one side of the plurality of cylinders (1), and the multi-cylinder engine further comprises: a controller (7) configured to control the action of each of the first regulating valves (3) and each of the second regulating valves (4).

5. A method of controlling a multi-cylinder engine, characterized by, comprising: In a multi-cylinder engine comprising a plurality of cylinders (1), a monoblock cylinder head (2), and a plurality of first regulating valves (3), the valve timing of each cylinder (1) and the actual operating parameters of the multi-cylinder engine are obtained, wherein the actual operating parameters include engine speed, engine fuel injection amount, engine intake air amount, and engine exhaust gas recirculation amount; and, For each of the cylinders (1), an EGR rate set value of the cylinder (1) is generated based on the engine intake air amount or the engine exhaust gas recirculation amount, wherein the EGR rate set value of each of the cylinders (1) is the same; An EGR flow set value of the cylinder (1) is obtained based on the EGR rate of the cylinder (1); The control logic of the corresponding first regulating valve (3) of the cylinder (1) is obtained, and an EGR flow actual value of the cylinder (1) is generated based on the engine intake air amount, the engine fuel injection amount, and the control logic; An opening degree feedforward value of the first regulating valve (3) is generated based on the EGR flow set value and the engine speed; and, The deviation between the EGR flow set value and the EGR flow actual value is obtained, and a PID control with feedforward is performed on the opening degree of the first regulating valve (3) based on the deviation and the opening degree feedforward value, so that the combustion state of each of the cylinders (1) is consistent by adjusting the EGR rate of the cylinder (1).

6. The method of claim 5, wherein, Further comprising: In the multi-cylinder engine comprising a plurality of second regulating valves (4), for each of the cylinders (1), the opening degree of the corresponding second regulating valve (4) of the cylinder (1) is adjusted based on the valve timing of the cylinder (1) and the actual operating parameters of the multi-cylinder engine, so that the exhaust state of each of the cylinders (1) is consistent by means of single-cylinder EGR regulation.

7. The method of claim 6, wherein, The valve timing includes spark advance angle and overlap angle.

8. The method of claim 7, wherein, The EGR rate set value is positively correlated with the EGR flow set value, and the EGR rate set value of the cylinder (1) is generated based on the engine intake air amount or the engine exhaust gas recirculation amount, comprising: The engine intake air amount and the engine exhaust gas recirculation amount are input into a pre-set EGR rate set value generation model to obtain the EGR rate set value of the cylinder (1), wherein the EGR rate set value generation model is configured to generate the EGR rate set value based on the engine intake air amount and the engine exhaust gas recirculation amount.

9. The method according to claim 7 or 8, characterized in that, The control logic is a control logic based on intake and exhaust strokes, and the control logic is configured to include: The first regulating valve (3) and the second regulating valve (4) corresponding to different cylinders (1) in which exhaust strokes and intake strokes are overlapped are both opened in the overlapping time to realize single-cylinder EGR control.

10. The method according to claim 7 or 8, characterized in that, The method further comprises: for each of the cylinders (1), obtaining an IQA code of an oil injector in the cylinder (1), and adjusting a driving waveform of the first regulating valve (3) and the second regulating valve (4) based on the IQA code; and, The EGR flow actual value of the cylinder (1) is generated based on the engine intake amount, the engine fuel injection amount and the control logic, which comprises: The engine intake amount and the engine fuel injection amount are input into a preset excess air coefficient generation model to obtain an excess air coefficient, wherein the excess air coefficient generation model is configured to generate the excess air coefficient based on the engine intake amount and the engine fuel injection amount; The overlap angle and the ignition advance angle of the cylinder (1) in the current working cycle are obtained based on the control logic; The number of cylinders of the multi-cylinder engine is obtained, and the opening and closing state and the opening time of the first regulating valve (3) corresponding to the cylinder (1) are generated based on the overlap angle, the ignition advance angle and the number of cylinders; and, The EGR flow actual value is generated based on the excess air coefficient and the opening and closing state and the opening time of the first regulating valve (3).

11. A motor vehicle, characterized in that The motor vehicle comprises the multi-cylinder engine according to any one of claims 1 to 4.

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