Low-pressure EGR flow control method, control system, storage medium and control device

Abstract

The present invention provides a low-pressure EGR flow control method, control system, storage medium, and control device. The low-pressure EGR flow control method includes: obtaining a target EGR flow and adjusting the EGR valve opening according to the target EGR flow; determining an interference valve; and entering the interference valve adjustment process. The interference valve adjustment process includes: determining a current opening combination of the interference valve and obtaining a first EGR flow change value corresponding to a collection period of the current opening combination of the interference valve; adjusting the opening of the interference valve and obtaining multiple adjustment opening combinations of the interference valve and second EGR flow change values ​​corresponding to the collection period of each adjustment opening combination; selecting the largest one of the first EGR flow change value and each second EGR flow change value, and using the corresponding opening combination as the current opening combination of the interference valve for the next cycle. The low-pressure EGR flow control method of the present invention can reduce the time when the engine and EGR flow are mismatched.

Description

Technical Field

[0001] The present application relates to the field of engine technology, and in particular to a low-pressure EGR flow control method, control system, storage medium, and control device. Background Art

[0002] In related technologies, when the engine operating conditions change, the EGR target flow rate is adjusted, and the EGR valve opening is adjusted accordingly, and the relevant control parameters of the engine change accordingly. Since the EGR valve opening changes, the flow through the EGR valve does not reach the target flow rate immediately, but there will be a certain delay in time, resulting in a mismatch between the relevant control parameters of the engine and the EGR flow rate within a certain period of time, causing combustion deterioration or detonation. Summary of the Invention

[0003] In view of this, the embodiments of the present application hope to provide a low-pressure EGR flow control method, control system, storage medium and control device, which can reduce the flow delay time of the EGR valve and reduce the time when the engine and EGR flow do not match.

[0004] To achieve the above objectives, an embodiment of the present application provides a low-pressure EGR flow control method, comprising:

[0005] Obtaining a target EGR flow rate and adjusting an EGR valve opening according to the target EGR flow rate;

[0006] Identify the interfering valve;

[0007] Entering the interference valve adjustment process, the interference valve adjustment process includes:

[0008] Determining a current opening combination of the interference valve, and obtaining a first EGR flow rate change value corresponding to a collection period of the current opening combination of the interference valve;

[0009] Adjusting the opening of the interference valve to obtain a plurality of adjustment opening combinations of the interference valve and a second EGR flow rate change value corresponding to a collection period of each adjustment opening combination;

[0010] Selecting the largest one among the first EGR flow rate change value and each second EGR flow rate change value, and using the opening combination corresponding thereto as the current opening combination of the interference valve in the next cycle;

[0011] It is determined whether the interference valve adjustment process is completed. If not, the interference valve adjustment process is circulated until it is determined that the interference valve adjustment process is completed.

[0012] In some embodiments, the step of determining the interfering valve comprises:

[0013] Determine whether the current working condition is a supercharging condition;

[0014] If so, determine that the turbine valve and mixing valve are interfering valves;

[0015] If not, determine that the throttle and mixing valves are interfering valves.

[0016] In some embodiments, the steps of determining the current opening combination of the interference valve and obtaining the first EGR flow rate change value corresponding to the acquisition period of the current opening combination of the interference valve include:

[0017] Establish multiple acquisition cycles of the current opening combination and obtain the first EGR flow rate at the start and end of each acquisition cycle;

[0018] According to the first EGR flow rates corresponding to the start point and the end point of the collection period, the first EGR flow rate change value corresponding to each collection period of the interference valve current opening combination is obtained.

[0019] In some embodiments, the step of adjusting the opening of the interference valve and obtaining a plurality of adjustment opening combinations of the interference valve and a second EGR flow rate change value corresponding to a collection period of each adjustment opening combination includes:

[0020] Determining a unit adjustment amount within a preset opening adjustment range of the interference valve;

[0021] Adjusting the current opening of the interference valve by a unit adjustment amount in a forward direction and a reverse direction to obtain multiple adjustment opening combinations of the interference valve;

[0022] Establishing a plurality of collection cycles for each adjustment opening combination, and obtaining a second EGR flow rate at a start point and an end point of each collection cycle for each adjustment opening combination;

[0023] According to the second EGR flow rates at the start and end points of each acquisition period of each adjustment opening combination, a second EGR flow rate change value corresponding to each acquisition period of each adjustment opening combination is obtained.

[0024] In some embodiments, if the throttle valve and the mixing valve are interference valves, the step of adjusting the opening of the interference valve and obtaining multiple adjustment opening combinations of the interference valve includes:

[0025] Determining a unit adjustment amount within a preset opening adjustment range of the throttle valve and the mixing valve;

[0026] Adjusting the current openings of the throttle valve and the mixing valve by a unit adjustment amount in a forward direction and a reverse direction to obtain the adjustment openings of the two throttle valves and the adjustment openings of the two mixing valves;

[0027] Combinations are established for the adjustment openings of the two throttle valves and the adjustment openings of the two mixing valves to obtain four adjustment opening combinations.

[0028] In some implementation schemes, the preset opening adjustment range is ±5% of the current opening combination of the interference valve.

[0029] In some embodiments, the step of determining whether the interference valve adjustment process is completed includes at least one of the following:

[0030] Determine the limit opening of the interference valve according to the current opening combination of the interference valve and the preset opening adjustment range; judge whether the current opening combination of the interference valve is not less than the limit opening of the interference valve; if so, the interference valve adjustment process cycle ends;

[0031] Obtaining a difference between the EGR flow rate of the current opening combination and the target EGR flow rate; determining whether the difference between the EGR flow rate of the current opening combination and the target EGR flow rate is within a preset range; if so, terminating the interference valve adjustment process loop;

[0032] Determine whether the opening combination corresponding to the largest EGR flow change value is the current opening combination. If so, the loop stops.

[0033] An embodiment of the present application provides a storage medium storing computer-executable instructions. The computer-executable instructions can be executed by a processor to implement the steps of a low-pressure EGR flow control method.

[0034] An embodiment of the present application provides a low-pressure EGR system, comprising:

[0035] An acquisition module is used to obtain a target EGR flow rate and adjust the EGR valve opening according to the target EGR flow rate;

[0036] A determination module, configured to determine the interference valve;

[0037] A process module is used to enter the interference valve adjustment process, and the interference valve adjustment process includes: determining the current opening combination of the interference valve, obtaining the first EGR flow change value corresponding to the acquisition period of the current opening combination of the interference valve; adjusting the opening of the interference valve, obtaining multiple adjustment opening combinations of the interference valve and the second EGR flow change value corresponding to the acquisition period of each adjustment opening combination; selecting the largest one among the first EGR flow change value and each second EGR flow change value, and using the corresponding opening combination as the current opening combination of the interference valve in the next cycle; judging whether the interference valve adjustment process is ended, and if not, looping the interference valve adjustment process until it is judged that the interference valve adjustment process is ended.

[0038] An embodiment of the present application provides a low-pressure EGR flow control device, the low-pressure EGR flow control device comprising:

[0039] a memory, wherein the memory stores computer-executable instructions;

[0040] A processor is used to execute the computer executable instructions to implement the steps of the low-pressure EGR flow control method.

[0041] The low-pressure EGR flow control method, control system, storage medium and control device of the embodiment of the present application adjust the EGR valve opening according to the target EGR flow, adjust the opening of the interference valve, cause disturbance to the actual EGR flow of the EGR valve, and obtain the first EGR flow change value corresponding to the acquisition period of the current opening combination of the interference valve by determining the current opening combination of the interference valve; adjust the opening of the interference valve to obtain multiple adjustment opening combinations of the interference valve and the second EGR flow change value corresponding to the acquisition period of each adjustment opening combination; among the first EGR flow change value and each second EGR flow change value, select the largest one, that is, the one that most significantly reduces the time it takes for the actual EGR flow to reach the target EGR flow within the acquisition period, and use its corresponding opening combination as the current opening combination of the interference valve in the next cycle, so as to achieve the purpose of reducing the time it takes for the actual EGR flow to reach the target EGR flow by adjusting the opening of the interference valve. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 Schematic diagram of a low-pressure EGR flow control method according to an embodiment of the present application. DETAILED DESCRIPTION

[0043] The following embodiments of the present invention are described in further detail with reference to the accompanying drawings and examples. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0044] In the description of the embodiments of the present application, the terms "first", "second" and "third" are used for descriptive purposes only and should not be understood as indicating or implying relative importance.

[0045] The present invention provides a method for controlling low-pressure EGR flow, comprising the following steps:

[0046] S1. Obtain target EGR flow rate and adjust the EGR valve opening according to the target EGR flow rate.

[0047] S2. Determine the interference valve. It is understandable that the interference valve is located in the airflow path of the engine intake and exhaust.

[0048] S3, entering the interference valve adjustment process, the interference valve adjustment process includes:

[0049] S4. Determine the current opening combination of the interference valve, and obtain a first EGR flow rate change value corresponding to a collection period of the current opening combination of the interference valve.

[0050] S5. Adjust the opening of the interference valve, obtain multiple adjustment opening combinations of the interference valve and second EGR flow rate change values ​​corresponding to the collection period of each adjustment opening combination.

[0051] S6. Select the largest one among the first EGR flow rate change value and each second EGR flow rate change value, and use the corresponding opening combination as the current opening combination of the interference valve in the next cycle.

[0052] S7. Determine whether the interference valve adjustment process is completed. If not, loop the interference valve adjustment process until it is determined that the interference valve adjustment process is completed.

[0053] It should be noted that in step S1, the actual EGR flow of the EGR valve is constantly approaching the target EGR flow, and the above process is inevitable even if the interference valve is not adjusted. In step S5, adjusting the opening of the interference valve will cause disturbances to the actual EGR flow of the EGR valve.

[0054] In steps S4 and S5, the magnitude of the first EGR flow change value and each second EGR flow change value indicates the degree of change of the EGR flow during the acquisition period. If the actual EGR flow after the disturbance changes less during the acquisition period, that is, the value of the first EGR flow change value or each second EGR flow change value is small, it means that the speed at which the actual EGR flow approaches the target EGR flow is slowing down. If the actual EGR flow after the disturbance changes more during the acquisition period, that is, the value of the first EGR flow change value or each second EGR flow change value is large, it means that the speed at which the actual EGR flow approaches the target EGR flow is accelerating.

[0055] The low-pressure EGR flow control method of the present invention adjusts the EGR valve opening according to a target EGR flow, adjusts the opening of the interference valve, and thereby disturbs the actual EGR flow of the EGR valve. The method determines a current opening combination of the interference valve and obtains a first EGR flow change value corresponding to a collection period of the current opening combination of the interference valve. The method also adjusts the opening of the interference valve to obtain multiple opening combinations of the interference valve and second EGR flow change values ​​corresponding to the collection period of each opening combination. The method then selects the largest of the first and second EGR flow change values, i.e., the one that most significantly reduces the time required for the actual EGR flow to reach the target EGR flow within the collection period, and uses the opening combination corresponding to the largest value as the current opening combination of the interference valve for the next cycle. This method reduces the time required for the actual EGR flow to reach the target EGR flow by adjusting the opening of the interference valve, thereby reducing the risk of mismatch between relevant engine control parameters and the actual EGR flow. The relevant engine control parameters may include ignition angle, variable valve timing (VVT), etc.

[0056] It should be noted that the EGR flow rate is the engine exhaust gas circulation flow rate. The engine exhaust gas flows into the circulation branch after passing through the turbine valve of the turbine. The circulation branch is equipped with an EGR valve. The exhaust gas flowing out of the circulation branch is mixed with the fresh air passing through the mixing valve, and flows into the engine after passing through the compressor and throttle.

[0057] The specific implementation of the above steps S4 to S7 will be described in detail below.

[0058] In step S4, the current opening combination of the interference valve is determined, and the first EGR flow change value corresponding to the acquisition period of the current opening combination of the interference valve is obtained. Wherein, if the number of the interference valve is one, the current opening combination of the interference valve is the current opening of the interference valve. If the number of the interference valve is multiple, the current opening combination of the interference valve is the current opening of multiple interference valves. At this time, the first EGR flow change value corresponding to the acquisition period of the current opening combination is the multiple first EGR flow change values ​​corresponding to the acquisition period of multiple current opening combinations. Wherein, the first EGR flow change value is the absolute value of the EGR flow change. The EGR flow is the exhaust gas circulation flow, which can be obtained at the EGR valve, for example, by setting a flow meter at the outlet of the EGR valve.

[0059] It should be noted that the number of collection cycles can be one or more. When the number of collection cycles is more than one, the first EGR flow rate change value corresponding to the collection cycle of the current opening combination is the multiple first EGR flow rate change values ​​corresponding to the multiple collection cycles of the current opening combination.

[0060] It is understandable that the duration of the acquisition cycle is very short, for example, 10 milliseconds.

[0061] In step S5, the opening of the interference valve is adjusted to obtain a plurality of adjustment opening combinations of the interference valve and a second EGR flow rate change value corresponding to a collection period of each adjustment opening combination. The adjustment opening combination is the adjustment opening combination of the interference valve.

[0062] It is understandable that the number of collection cycles can be one or more. When the number of collection cycles is multiple, the second EGR flow rate change value corresponding to the collection cycle of each of the adjustment opening combinations is the multiple second EGR flow rate change values ​​corresponding to each collection cycle of the multiple adjustment opening combinations.

[0063] The largest one is selected, and its corresponding opening combination is used as the current opening combination of the interference valve for the next cycle. That is, the interference valve opening combination that can shorten the time it takes for the actual EGR flow rate to reach the target EGR flow rate is selected as the current opening combination of the interference valve for the next cycle, and this time can be shortened with each cycle.

[0064] In step S6, the largest of the first EGR flow rate change value and each of the second EGR flow rate change values ​​is selected, and the corresponding opening combination is used as the current opening combination of the interference valve for the next cycle. It is understood that each first EGR flow rate change value corresponds to a current opening combination, and each second EGR flow rate change value corresponds to an adjusted opening combination.

[0065] It can be understood that after adjusting the EGR valve opening according to the target EGR flow rate, the actual EGR flow rate of the EGR valve continuously approaches the target EGR flow rate until it reaches the target EGR flow rate. During this process, adjusting the opening of the interference valve will cause a disturbance in the actual EGR flow rate of the EGR valve. If the actual EGR flow rate after the disturbance changes little during the acquisition cycle, it indicates that the speed at which the actual EGR flow rate approaches the target EGR flow rate is slowing down. If the actual EGR flow rate after the disturbance changes significantly during the acquisition cycle, it indicates that the actual EGR flow rate is approaching the target EGR flow rate faster, thus shortening the overall time.

[0066] For example, in step S4, the first EGR flow rate change value is n1, and in step S5, the second EGR flow rate change value is n 2a 、n 2b ...If n 2a The largest, indicating that n 2a The corresponding adjustment opening combination changes most significantly in this acquisition cycle, that is, in this acquisition cycle, the speed at which the actual EGR flow approaches the target EGR flow is significantly accelerated, thus shortening the overall time.

[0067] That is, an interference valve opening combination that can shorten the time it takes for the actual EGR flow to reach the target EGR flow is selected as the current opening combination of the interference valve in the next cycle, and the above time can be shortened in each cycle.

[0068] Exemplarily, step S2 includes:

[0069] S21. Determine whether the current operating condition is a supercharging condition.

[0070] S22. If yes, determine that the turbine valve and the mixing valve are interference valves.

[0071] The turbine valve controls the flow and pressure of intake and exhaust air to ensure the proper operation of the turbine. It is located in the upstream pipeline of the EGR valve, between the engine's exhaust port and the EGR valve's intake port. The mixing valve regulates engine intake and is located upstream of the engine's intake port.

[0072] S23. If not, determine that the throttle valve and the mixing valve are interfering valves.

[0073] Among them, the throttle is a controllable valve located upstream of the engine air intake and is used to control the mixture of air and exhaust gas entering the engine.

[0074] It should be noted that the purpose of specifying the turbine valve and mixing valve as interfering valves during boost conditions, and the throttle valve and mixing valve as interfering valves during non-boost conditions, is to achieve decoupling, reduce the number of variable modification dimensions, simplify the model, and improve efficiency. Specifically, if there are more than two interfering valves, the number of adjustment opening combinations involved in step S5 will increase significantly, making the calculation complex and implementation difficult.

[0075] The following uses the example of multiple collection cycles as an example:

[0076] Exemplarily, step S4 includes:

[0077] S41. Establish multiple collection cycles for the current opening combination and obtain the first EGR flow rate at the start and end of each collection cycle. It is understood that the duration of each collection cycle is equal. Each collection cycle can be a continuous period of multiple time periods. The first EGR flow rate at the start and end of each collection cycle refers to the EGR flow rate obtained at the start time of each collection cycle and the EGR flow rate obtained at the end time of each collection cycle.

[0078] S42. Obtain a first EGR flow rate change value corresponding to each collection period for the current combination of the interference valve opening based on the first EGR flow rates corresponding to the start and end points of the collection period. In some embodiments, the absolute value of the difference between the first EGR flow rate corresponding to the start point of the collection period and the first EGR flow rate corresponding to the end point of the collection period is used as the first EGR flow rate change value for that collection period. The first EGR flow rate change value corresponding to each collection period is calculated in this manner.

[0079] Exemplarily, step S5 includes:

[0080] S51 . Determine a unit adjustment amount within a preset opening adjustment range of the interference valve.

[0081] It should be noted that the preset opening adjustment range of the interference valve is different from the opening range of the interference valve. The preset opening adjustment range of the interference valve is the maximum adjustment range after entering the interference valve adjustment process. In some embodiments, the preset opening adjustment range is ±5% of the current opening combination of the interference valve. The opening range of the interference valve is between 0-100%.

[0082] S52: Adjust the current opening of the interference valve by one unit adjustment amount in the forward direction and the reverse direction to obtain multiple adjustment opening combinations. It can be understood that adjusting the current opening of the interference valve by one unit adjustment amount in the forward direction and the reverse direction, i.e., increasing the current opening by one unit adjustment amount and decreasing the current opening by one unit adjustment amount, respectively, obtains two adjustment openings after the interference valve is adjusted.

[0083] S53. Establish multiple collection cycles for each adjustment opening combination, and obtain the second EGR flow rate at the start and end of each collection cycle for each adjustment opening combination. It is understood that the duration of each collection cycle is equal. Each collection cycle can be a plurality of consecutive time periods.

[0084] The second EGR flow rate at the start and end point of each acquisition period of each adjustment opening combination, that is, the EGR flow rate obtained at the start time point of each acquisition period of each adjustment opening combination and the EGR flow rate obtained at the end time point of each acquisition period of each adjustment opening combination.

[0085] For example, if there are four adjustment opening combinations and four collection cycles, the second EGR flow rate is obtained at the start and end points of each collection cycle for each opening combination. This results in a total of 16 starting second EGR flow rates and 16 ending second EGR flow rates. If the collection cycles are consecutive, the second EGR flow rate at the start and end points of two adjacent collection cycles will be the same.

[0086] S54 , obtaining a second EGR flow rate change value corresponding to each collection period of each adjustment opening combination according to the second EGR flow rates at the start and end points of each collection period of each adjustment opening combination.

[0087] In some embodiments, the absolute value of the difference between the second EGR flow rate corresponding to the start point of a collection period and the second EGR flow rate corresponding to the end point of the collection period is used as the second EGR flow rate change value for that collection period. Based on this, the second EGR flow rate change value corresponding to each collection period for each of the aforementioned control opening combinations is calculated.

[0088] For example, if the interfering valve is a throttle valve and a mixing valve, that is, if the working condition is non-boosting, in step S5, the step of adjusting the opening of the interfering valve and obtaining multiple adjustment opening combinations of the interfering valve includes:

[0089] S51a: Determine a unit adjustment amount within the preset opening adjustment ranges of the throttle valve and the mixing valve. That is, the preset opening adjustment range of the throttle valve is divided into a plurality of unit adjustment amounts. The preset opening adjustment range of the mixing valve is also divided into a plurality of unit adjustment amounts.

[0090] It should be noted that if the preset opening adjustment range is too large, it will cause greater negative disturbances to the engine intake and exhaust. After testing, it has been determined that when the preset opening adjustment range is ±5% of the current opening combination of the interference valve, the above negative disturbances can be greatly reduced.

[0091] For example, if the current opening of the throttle and the mixing valve are both k, the preset opening adjustment range of the throttle is k±5%, and the preset opening adjustment range of the mixing valve is k±5%. If the above preset opening adjustment range is divided into multiple intervals, each of which is 1%, the unit adjustment amount is 1%.

[0092] S52a, adjusting the current openings of the throttle valve and the mixing valve by a unit adjustment amount in a forward direction and a reverse direction to obtain the adjustment openings of the two throttle valves and the adjustment openings of the two mixing valves.

[0093] The adjustment amount is adjusted by one unit in the forward direction and the reverse direction, that is, the adjustment amount is increased by one unit and decreased by one unit. In this way, two adjustment openings of the throttle valve and two adjustment openings of the mixing valve are obtained after adjustment.

[0094] S52b: Create combinations of the adjustment openings of the two throttle valves and the adjustment openings of the two mixing valves to obtain four combinations of adjustment openings.

[0095] For example, the throttle valve has two adjustable openings, K1 and K2, and the mixing valve has two adjustable openings, K3 and K4. After establishing the combination, four adjustable opening combinations are obtained: (K1, K3); (K1, K4); (K2, K3); (K2, K4).

[0096] It can be understood that if it is a boost working condition, that is, when the interfering valve is a turbine valve and a mixing valve, in step S5, the steps of adjusting the opening of the interfering valve and obtaining multiple adjustment opening combinations of the interfering valve are roughly the same as the above steps.

[0097] Exemplarily, step S7 includes at least one of the following:

[0098] S7a. Determine the limit opening of the interference valve according to the current opening of the interference valve and the preset opening adjustment range; judge whether the current opening combination of the interference valve is not less than the limit opening of the interference valve; if so, the interference valve adjustment process cycle ends.

[0099] S7b. Obtain the difference between the EGR flow rate of the current opening combination and the target EGR flow rate; determine whether the difference between the EGR flow rate of the current opening combination and the target EGR flow rate is within a preset range; if so, the interference valve adjustment process cycle ends.

[0100] S7c. Determine whether the opening combination corresponding to the largest one of the first EGR flow rate change value and each second EGR flow rate change value is the current opening combination. If so, the loop stops.

[0101] It can be understood that step S7 includes one or more of steps S7a, S7b, and S7c.

[0102] In some embodiments, step S7 includes three of steps S7a, S7b, and S7c, and the loop stops if any one of S7a, S7b, and S7c is satisfied.

[0103] The above steps S7a, S7b, and S7c are described in detail below.

[0104] S7a, determining the limit opening of the interference valve according to the current opening of the interference valve and the preset opening adjustment range. For example, if the current opening is K and the preset opening adjustment range is ±5%, the limit openings are K+5% and K-5% respectively.

[0105] A determination is made as to whether the current opening combination of the interference valve is not less than the maximum opening of the interference valve; if so, the interference valve adjustment process loop ends. It will be appreciated that the current opening combination of the interference valve may change during the interference valve adjustment process loop. After multiple cycles, the current opening combination of the interference valve may reach the maximum opening, at which point the interference valve adjustment process loop ends.

[0106] S7b: Obtain the difference between the EGR flow rate of the current opening combination and the target EGR flow rate. Determine whether the difference between the EGR flow rate of the current opening combination and the target EGR flow rate is within a preset range; if so, the interference valve adjustment process loop ends.

[0107] It will be understood that the EGR flow rate for the current opening combination is the measured EGR flow rate for the current opening combination. The preset range can be zero, meaning that the interference valve adjustment process cycle ends when the EGR flow rate for the current opening is equal to the target EGR flow rate. The preset range can also be a range of values ​​not equal to zero, such that the interference valve adjustment process cycle ends when the EGR flow rate for the current opening is close to the target EGR flow rate.

[0108] S7c. Determine whether the opening combination corresponding to the largest one of the first EGR flow rate change value and each second EGR flow rate change value is the current opening combination. If so, the loop stops.

[0109] It can be understood that if the largest one among the EGR flow rate change values ​​is the current opening combination, it means that the current opening combination is already the fastest and most time-saving opening combination to adjust, so the cycle stops.

[0110] An embodiment of the present application further provides a storage medium storing computer-executable instructions, which can be executed by a processor to implement the steps of the low-pressure EGR flow control method.

[0111] The present application also provides a low-pressure EGR system, comprising:

[0112] The acquisition module is used to obtain the target EGR flow rate and adjust the EGR valve opening according to the target EGR flow rate.

[0113] A determination module is used to determine the interference valve.

[0114] A process module is used to enter the interference valve adjustment process, and the interference valve adjustment process includes: determining the current opening combination of the interference valve, obtaining the first EGR flow change value corresponding to the acquisition period of the current opening combination of the interference valve; adjusting the opening of the interference valve, obtaining multiple adjustment opening combinations of the interference valve and the second EGR flow change value corresponding to the acquisition period of each adjustment opening combination; selecting the largest one among the first EGR flow change value and each second EGR flow change value, and using the corresponding opening combination as the current opening combination of the interference valve in the next cycle; judging whether the interference valve adjustment process is ended, and if not, looping the interference valve adjustment process until it is judged that the interference valve adjustment process is ended.

[0115] The embodiment of the present application further provides a low-pressure EGR flow control device, the low-pressure EGR flow control device comprising:

[0116] A memory is provided for storing computer-executable instructions.

[0117] A processor is used to execute the computer executable instructions to implement the steps of the low-pressure EGR flow control method.

[0118] In the description of this application, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the embodiments of the present application. In this application, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine different embodiments or examples described in this application and features of different embodiments or examples without contradiction.

[0119] The foregoing description is merely a preferred embodiment of the present application and is not intended to limit the present application. Persons skilled in the art will readily appreciate that various modifications and variations are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present application shall be included within the scope of protection of the present application.

Claims

1. A low-pressure EGR flow control method, characterized in that: include: Obtaining a target EGR flow rate and adjusting an EGR valve opening according to the target EGR flow rate; Identify the interfering valve; Entering the interference valve adjustment process, the interference valve adjustment process includes: Determining a current opening combination of the interference valve, and obtaining a first EGR flow rate change value corresponding to a collection period of the current opening combination of the interference valve; Adjusting the opening of the interference valve to obtain a plurality of adjustment opening combinations of the interference valve and a second EGR flow rate change value corresponding to a collection period of each adjustment opening combination; Selecting the largest one among the first EGR flow rate change value and each second EGR flow rate change value, and using the opening combination corresponding thereto as the current opening combination of the interference valve in the next cycle; Determine whether the interference valve adjustment process is completed. If not, loop the interference valve adjustment process until it is determined that the interference valve adjustment process is completed.

2. A low-pressure EGR flow control method according to claim 1, characterized in that: The step of determining the interfering valve includes: Determine whether the current working condition is a supercharging condition; If so, determine that the turbine valve and mixing valve are interfering valves; If not, determine that the throttle and mixing valves are the interfering valves.

3. A low-pressure EGR flow control method according to claim 2, characterized in that: The steps of determining the current opening combination of the interference valve and obtaining the first EGR flow rate change value corresponding to the acquisition period of the current opening combination of the interference valve include: Establish multiple acquisition cycles of the current opening combination and obtain the first EGR flow rate at the start and end of each acquisition cycle; According to the first EGR flow rates corresponding to the start point and the end point of the collection period, the first EGR flow rate change value corresponding to each collection period of the interference valve current opening combination is obtained.

4. A low-pressure EGR flow control method according to claim 2 or 3, characterized in that: The steps of adjusting the opening of the interference valve and obtaining a plurality of adjustment opening combinations of the interference valve and a second EGR flow rate change value corresponding to a collection period of each adjustment opening combination include: Determining a unit adjustment amount within a preset opening adjustment range of the interference valve; Adjusting the current opening of the interference valve by a unit adjustment amount in a forward direction and a reverse direction to obtain multiple adjustment opening combinations of the interference valve; Establishing a plurality of collection cycles for each adjustment opening combination, and obtaining a second EGR flow rate at a start point and an end point of each collection cycle for each adjustment opening combination; According to the second EGR flow rates at the start and end points of each acquisition period of each adjustment opening combination, a second EGR flow rate change value corresponding to each acquisition period of each adjustment opening combination is obtained.

5. A low-pressure EGR flow control method according to claim 4, characterized in that: If the throttle valve and the mixing valve are interference valves, the step of adjusting the opening of the interference valve and obtaining multiple adjustment opening combinations of the interference valve includes: Determining a unit adjustment amount within a preset opening adjustment range of the throttle valve and the mixing valve; Adjusting the current openings of the throttle and the mixing valve by unit adjustment amounts in a forward direction and a reverse direction to obtain the adjustment openings of the two throttles and the adjustment openings of the two mixing valves; Combinations are established for the adjustment openings of the two throttle valves and the adjustment openings of the two mixing valves to obtain four adjustment opening combinations.

6. A low-pressure EGR flow control method according to claim 4, characterized in that: The preset opening adjustment range is ±5% of the current opening combination of the interference valve.

7. The low-pressure EGR flow control method according to claim 1, characterized in that: The step of determining whether the interference valve adjustment process is completed includes at least one of the following: Determining the limit opening of the interference valve according to the current opening combination of the interference valve and the preset opening adjustment range; judging whether the current opening combination of the interference valve is not less than the limit opening of the interference valve; If so, the interference valve adjustment process cycle ends; Obtaining a difference between the EGR flow rate of the current opening combination and the target EGR flow rate; determining whether a difference between the EGR flow rate of the current opening combination and the target EGR flow rate is within a preset range; If so, the interference valve adjustment process cycle ends; Determine whether the opening combination corresponding to the largest EGR flow change value is the current opening combination. If so, the loop stops.

8. A storage medium, characterized in that: The storage medium stores computer-executable instructions, and the computer-executable instructions can be executed by a processor to implement the steps of the low-pressure EGR flow control method according to any one of claims 1 to 7.

9. A low-pressure EGR system, characterized in that: include: An acquisition module is used to obtain a target EGR flow rate and adjust the EGR valve opening according to the target EGR flow rate; A determination module, used for determining an interfering valve; A process module is used to enter an interference valve adjustment process, wherein the interference valve adjustment process includes: determining a current opening combination of the interference valve, and obtaining a first EGR flow rate change value corresponding to a collection period of the current opening combination of the interference valve; Adjust the opening of the interference valve, obtain multiple adjustment opening combinations of the interference valve and the second EGR flow change value corresponding to the acquisition period of each adjustment opening combination; select the largest one among the first EGR flow change value and each second EGR flow change value, and use the corresponding opening combination as the current opening combination of the interference valve in the next cycle; determine whether the interference valve adjustment process is completed, if not, loop the interference valve adjustment process until it is determined that the interference valve adjustment process is completed.

10. A low-pressure EGR flow control device, characterized in that: The low-pressure EGR flow control device includes: a memory, wherein the memory stores computer-executable instructions; A processor is used to execute the computer executable instructions to implement the steps of the low-pressure EGR flow control method according to any one of claims 1 to 7.

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