Methods, systems, electronic devices, and vehicles for determining a parameter value for an egr rate

Abstract

This application provides a method, system, electronic device, and vehicle for determining EGR rate parameter values. The method includes: acquiring the current engine speed and torque; acquiring a target EGR rate parameter value corresponding to the current engine speed and torque; determining an intermediate EGR rate parameter value based on the target EGR rate parameter value and the engine's air-fuel ratio limiting EGR rate parameter value; and comparing the intermediate EGR rate parameter value with the engine's original EGR rate parameter value to determine an EGR rate requirement value. This application obtains the EGR rate requirement value by comparing the intermediate EGR rate parameter value determined based on the target EGR rate parameter value and the engine's air-fuel ratio limiting EGR rate parameter value with the engine's original EGR rate parameter value. This allows for effective reduction of NOx emissions when the engine operates at the required EGR rate value.

Description

Technical Field

[0001] This application relates to the field of engine technology, and in particular to a method, system, electronic equipment, and vehicle for determining EGR rate parameter values. Background Technology

[0002] Currently, EGR (Exhaust Gas Recirculation System) is the most effective technology for reducing NOx in modern diesel engines. Its working principle is to mix a portion of exhaust gas with fresh air before entering the cylinder, reducing the oxygen content of the mixture and inhibiting NOx production.

[0003] However, under transient engine conditions, such as acceleration, the engine's airflow response is slow, and the actual boost pressure cannot be established quickly. As a result, the amount of fresh air entering the engine is insufficient, triggering the air-fuel ratio smoke limit EGR rate, which leads to a sharp increase in NOx formation and causes the engine's NOx emissions to exceed the standard.

[0004] To address the above problems, this application proposes a method for determining the EGR rate parameter value. Summary of the Invention

[0005] In view of the above problems, this application provides a method, system, electronic device and vehicle for determining the EGR rate parameter value, in order to solve the problem in the prior art that when the engine is under acceleration, due to the slow response speed of the engine air circuit, the actual boost pressure cannot be established quickly, the amount of fresh air entering the engine is insufficient, triggering the air-fuel ratio smoke limit EGR rate, thereby causing the NOx generation to increase sharply and the engine NOx emission to exceed the standard.

[0006] A first aspect of this application provides a method for determining an EGR rate parameter value, the method comprising:

[0007] Obtain the current engine speed and torque;

[0008] Based on the current engine speed and torque, obtain the target EGR rate parameter value corresponding to the engine speed and torque;

[0009] Based on the target EGR rate parameter value and the engine's air-fuel ratio limiting EGR rate parameter value, an intermediate EGR rate parameter value is determined;

[0010] The intermediate EGR rate parameter value is compared with the original EGR rate parameter value of the engine to determine the required EGR rate value.

[0011] Optionally, comparing the intermediate EGR rate parameter value with the original EGR rate parameter value of the engine to determine the EGR rate requirement value includes:

[0012] Based on the current engine speed and torque, obtain the original EGR rate parameter value;

[0013] The intermediate EGR rate parameter value is compared with the original EGR rate parameter value, and the smaller of the intermediate EGR rate parameter value and the original EGR rate parameter value is determined as the EGR rate requirement value.

[0014] Optionally, determining the intermediate EGR rate parameter value based on the target EGR rate parameter value and the engine's air-fuel ratio-limited EGR rate parameter value includes:

[0015] Obtain the current actual boost pressure of the engine, and determine the current operating condition of the engine based on the actual boost pressure;

[0016] When the operating condition is a rapid acceleration condition, the larger of the target EGR rate parameter value and the engine's air-fuel ratio limiting EGR rate parameter value is determined as the intermediate EGR rate parameter value.

[0017] When the operating condition is a mild acceleration condition, the smaller of the target EGR rate parameter value and the air-fuel ratio limiting EGR rate parameter value is determined as the intermediate EGR rate parameter value, wherein the air-fuel ratio limiting EGR rate parameter value is calculated based on the current engine speed and torque.

[0018] Optionally, obtaining the current actual boost pressure of the engine and determining the current operating condition of the engine based on the actual boost pressure includes:

[0019] Based on the current engine speed and torque, determine the current required boost pressure of the engine;

[0020] If the difference between the actual boost pressure and the required boost pressure is greater than a first pressure threshold, the current operating condition of the engine is determined to be a rapid acceleration condition.

[0021] If the difference between the actual boost pressure and the required boost pressure is greater than or equal to a second pressure threshold, and less than or equal to a first pressure threshold, the current operating condition of the engine is determined to be a mild acceleration condition.

[0022] Optionally, obtaining the target EGR rate parameter value corresponding to the current engine speed and torque includes:

[0023] Based on the current engine speed and torque, a preset minimum EGR rate limit pulse spectrum is queried to obtain the target EGR rate parameter value corresponding to the engine speed and torque. The minimum EGR rate limit pulse spectrum represents the mapping relationship between the engine speed and torque and the target EGR rate parameter value.

[0024] Optionally, obtaining the original EGR rate parameter value based on the current engine speed and torque includes:

[0025] Based on the current engine speed and torque, a preset original EGR rate demand pulse spectrum is queried to obtain the original EGR rate parameter value corresponding to the engine speed and torque. The original EGR rate demand pulse spectrum represents the mapping relationship between the engine speed and torque and the original EGR rate parameter value.

[0026] Optionally, the air-fuel ratio limiting EGR rate parameter value is calculated based on the current engine speed and torque, including:

[0027] Obtain the current air-fuel ratio of the engine;

[0028] Based on the current engine speed and torque, determine the minimum air-fuel ratio limit and the maximum air-fuel ratio limit corresponding to the engine speed and torque;

[0029] The air-fuel ratio limit EGR rate parameter value is determined based on the air-fuel ratio, the minimum air-fuel ratio limit, and the maximum air-fuel ratio limit.

[0030] A second aspect of this application provides a system for determining an EGR rate parameter value, the system comprising:

[0031] The first acquisition module is used to acquire the current engine speed and torque;

[0032] The second acquisition module is used to acquire the target EGR rate parameter value corresponding to the engine speed and torque based on the current engine speed and torque.

[0033] The first determining module is used to determine an intermediate EGR rate parameter value based on the target EGR rate parameter value and the air-fuel ratio limiting EGR rate parameter value of the engine.

[0034] The second determining module is used to compare the intermediate EGR rate parameter value with the original EGR rate parameter value of the engine to determine the EGR rate requirement value.

[0035] Optionally, the step of comparing the intermediate EGR rate parameter value with the original EGR rate parameter value of the engine to determine the EGR rate requirement value, the second determining module includes:

[0036] The first acquisition submodule is used to acquire the original EGR rate parameter value based on the current engine speed and torque;

[0037] The first determining submodule is used to compare the intermediate EGR rate parameter value with the original EGR rate parameter value, and determine the smaller of the intermediate EGR rate parameter value and the original EGR rate parameter value as the EGR rate requirement value.

[0038] Optionally, the first determining module, which determines an intermediate EGR rate parameter value based on the target EGR rate parameter value and the engine's air-fuel ratio-limited EGR rate parameter value, includes:

[0039] The second acquisition submodule is used to acquire the current actual boost pressure of the engine and determine the current operating condition of the engine based on the actual boost pressure.

[0040] The second determining submodule is used to determine the larger of the target EGR rate parameter value and the engine's air-fuel ratio limiting EGR rate parameter value as the intermediate EGR rate parameter value when the operating condition is a rapid acceleration condition.

[0041] The third determining submodule is used to determine the smaller of the target EGR rate parameter value and the air-fuel ratio limiting EGR rate parameter value as the intermediate EGR rate parameter value when the operating condition is a mild acceleration condition. The air-fuel ratio limiting EGR rate parameter value is calculated based on the current engine speed and torque.

[0042] Optionally, the second acquisition submodule, which acquires the current actual boost pressure of the engine and determines the current operating condition of the engine based on the actual boost pressure, includes:

[0043] The first determining subunit is used to determine the current required boost pressure of the engine based on the current engine speed and torque.

[0044] The second determining subunit is used to determine that the current operating condition of the engine is a rapid acceleration condition when the difference between the actual boost pressure and the required boost pressure is greater than a first pressure threshold.

[0045] The third determining subunit is used to determine that the current operating condition of the engine is a mild acceleration condition when the difference between the actual boost pressure and the required boost pressure is greater than or equal to a second pressure threshold and less than or equal to the first pressure threshold.

[0046] Optionally, the second acquisition module, which obtains the target EGR rate parameter value corresponding to the current engine speed and torque, includes:

[0047] The third acquisition submodule is used to query a preset minimum EGR rate limit pulse spectrum based on the current engine speed and torque, and obtain the target EGR rate parameter value corresponding to the engine speed and torque, wherein the minimum EGR rate limit pulse spectrum represents the mapping relationship between the engine speed and torque and the target EGR rate parameter value.

[0048] Optionally, the first acquisition submodule, which obtains the original EGR rate parameter value based on the current engine speed and torque, includes:

[0049] The first acquisition subunit is used to query a preset original EGR rate demand pulse spectrum based on the current engine speed and torque, and obtain the original EGR rate parameter value corresponding to the engine speed and torque, wherein the original EGR rate demand pulse spectrum represents the mapping relationship between the engine speed and torque and the original EGR rate parameter value.

[0050] Optionally, the third determining submodule calculates the air-fuel ratio limiting EGR rate parameter value based on the current engine speed and torque, and includes:

[0051] The second acquisition subunit is used to acquire the current air-fuel ratio of the engine;

[0052] The fourth determining subunit is used to determine the minimum air-fuel ratio limit and the maximum air-fuel ratio limit corresponding to the current engine speed and torque.

[0053] The fifth determining subunit is used to determine the air-fuel ratio limit EGR rate parameter value based on the air-fuel ratio, the minimum air-fuel ratio limit, and the maximum air-fuel ratio limit.

[0054] A third aspect of this application provides an electronic device including a memory, a processor, and a computer program stored in the memory, wherein the processor executes the computer program to implement the method for determining an EGR rate parameter value as described in the first aspect of this application.

[0055] In a fourth aspect of this application, a vehicle is provided, the vehicle including electronic equipment as described in the third aspect of this application.

[0056] This application has the following advantages:

[0057] This application provides a method for determining an EGR rate parameter value. The method includes: acquiring the current engine speed and torque; acquiring a target EGR rate parameter value corresponding to the current engine speed and torque; determining an intermediate EGR rate parameter value based on the target EGR rate parameter value and the engine's air-fuel ratio limiting EGR rate parameter value; and comparing the intermediate EGR rate parameter value with the engine's original EGR rate parameter value to determine an EGR rate requirement value. This application obtains the EGR rate requirement value by comparing the intermediate EGR rate parameter value determined based on the target EGR rate parameter value and the engine's air-fuel ratio limiting EGR rate parameter value with the engine's original EGR rate parameter value. This allows for effective reduction of NOx emissions when the engine operates at this EGR rate requirement value. Attached Figure Description

[0058] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the description of the embodiments of this application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0059] Figure 1 This is a flowchart illustrating the steps of a method for determining an EGR rate parameter value provided in an embodiment of this application;

[0060] Figure 2 This is a flowchart illustrating a process for determining an EGR rate parameter value, as provided in an embodiment of this application.

[0061] Figure 3 This is a schematic diagram of an engine operating condition provided in an embodiment of this application;

[0062] Figure 4 This is a flowchart illustrating a method for determining an EGR rate parameter value, as provided in an embodiment of this application.

[0063] Figure 5 This is a schematic diagram of a system for determining the EGR rate parameter value provided in an embodiment of this application;

[0064] Figure 6 This is a schematic diagram of an electronic device provided in an embodiment of this application. Detailed Implementation

[0065] Exemplary embodiments of this application will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of this application are shown in the drawings, it should be understood that this application may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of this application and to fully convey the scope of this application to those skilled in the art.

[0066] Currently, EGR is the most effective technology for reducing NOx emissions in modern diesel engines. EGR stands for "Exhaust Gas Recirculation System." Its working principle is to mix a portion of exhaust gas with fresh air before introducing it into the cylinder, reducing the oxygen content of the mixture and inhibiting NOx production. Its mechanism is to introduce exhaust gas after combustion while reducing the amount of fresh air. Because the gases in the exhaust gas have a high specific heat capacity, they can effectively reduce the temperature inside the cylinder, thereby reducing the engine's NOx emissions.

[0067] Under steady-state conditions, when the amount of fresh air and fuel required for engine operation relatively meets actual needs, the air-fuel ratio limitation is not triggered, and the EGR rate requirement value is obtained from the original EGR rate requirement spectrum. However, under transient conditions, such as acceleration, due to the slow response speed of the internal combustion engine's air passage, the actual boost pressure cannot be established quickly, resulting in insufficient fresh air. Since engines are not allowed to operate below the air-fuel ratio limit, when the amount of fresh air is insufficient, to avoid increased particulate matter emissions, the air-fuel ratio smoke limitation will be triggered, and the EGR rate parameter value will be automatically limited to ensure the amount of fresh air required for normal combustion. When the EGR rate parameter value is limited, a sharp increase in NOx will occur, causing the engine's NOx emissions to exceed the standard. It should be noted that the engines described in this application are all diesel engines.

[0068] A first aspect of this application provides a method for determining an EGR rate parameter value, referring to... Figure 1 This is a flowchart illustrating the steps of a method for determining an EGR rate parameter value according to an embodiment of this application. The method includes:

[0069] Step S101: Obtain the current engine speed and torque;

[0070] Specifically, in this embodiment, the current engine speed and torque are first obtained. The engine speed can be obtained by the vehicle's ECU (Engine Control Unit) through an engine speed sensor, and the current engine torque can be obtained by the ECU through the opening of the accelerator pedal. Alternatively, the torque output of the engine can be monitored in real time by torque sensors installed in the engine and transmission system.

[0071] Step S102: Based on the current engine speed and torque, obtain the target EGR rate parameter value corresponding to the engine speed and torque;

[0072] Furthermore, based on the obtained current engine speed and current engine torque, the target EGR rate parameter value corresponding to the current engine speed and current engine torque is obtained, including:

[0073] Based on the current engine speed and torque, a preset minimum EGR rate limit pulse spectrum is queried to obtain the target EGR rate parameter value corresponding to the engine speed and torque. The minimum EGR rate limit pulse spectrum represents the mapping relationship between the engine speed and torque and the target EGR rate parameter value.

[0074] In this embodiment, different target EGR rate parameter values ​​corresponding to each engine speed and each engine torque are determined in advance, thereby obtaining a minimum EGR rate limit pulse spectrum that includes engine speed, engine torque, and target EGR rate parameter values. Based on the obtained current engine speed and current engine torque, the target EGR rate parameter values ​​corresponding to the current engine speed and current engine torque can be obtained by querying the minimum EGR rate limit pulse spectrum. In practical applications, the minimum EGR rate limit pulse spectrum can be obtained from the emission cycle. Specifically, under acceleration conditions, based on the engine's current speed and torque, the engine's current original EGR rate parameter value, air-fuel ratio limiting EGR rate parameter value, and NOx emission value are determined. Data is recorded every second, and the original EGR rate parameter value is compared with the air-fuel ratio limiting EGR rate parameter value. If the air-fuel ratio limiting EGR rate parameter value is less than the original EGR rate parameter value, meaning the original EGR rate parameter value is limited, and the NOx emission value is also high, then the original EGR rate parameter value needs to be adjusted to obtain a minimum EGR rate parameter value corresponding to the engine's current speed and torque. After a large number of cycle tests, the minimum EGR rate limit pulse spectrum is finally obtained.

[0075] Step S103: Determine the intermediate EGR rate parameter value based on the target EGR rate parameter value and the engine's air-fuel ratio limiting EGR rate parameter value;

[0076] Furthermore, based on the obtained target EGR rate parameter value and the engine's air-fuel ratio limiting EGR rate parameter value, an intermediate EGR rate parameter value is determined, wherein the engine's air-fuel ratio limiting EGR rate parameter value corresponds to the engine's current speed and engine's current torque.

[0077] Preferably, the air-fuel ratio limiting EGR rate parameter value is calculated based on the current engine speed and torque, including the following steps:

[0078] Obtain the current air-fuel ratio of the engine;

[0079] Based on the current engine speed and torque, determine the minimum air-fuel ratio limit and the maximum air-fuel ratio limit corresponding to the engine speed and torque;

[0080] The air-fuel ratio limit EGR rate parameter value is determined based on the air-fuel ratio, the minimum air-fuel ratio limit, and the maximum air-fuel ratio limit.

[0081] In this embodiment of the application, the current air-fuel ratio of the engine is obtained, specifically based on the ratio of the mass of air to the mass of fuel in the air-fuel mixture in the current combustion chamber of the engine.

[0082] The air-fuel ratio limit is typically a range between a minimum and a maximum value. The engine's air-fuel ratio cannot exceed this range. The maximum and minimum air-fuel ratio limits can be obtained from a table based on the engine's current speed and torque. The engine's air-fuel ratio limit EGR rate parameter value can be obtained using the formula: Air-fuel ratio limit EGR rate parameter value = (Current air-fuel ratio - Minimum air-fuel ratio limit) / (Maximum air-fuel ratio limit - Minimum air-fuel ratio limit).

[0083] Further, determining the intermediate EGR rate parameter value based on the target EGR rate parameter value and the engine's air-fuel ratio-limited EGR rate parameter value includes:

[0084] Obtain the current actual boost pressure of the engine, and determine the current operating condition of the engine based on the actual boost pressure;

[0085] When the operating condition is a rapid acceleration condition, the larger of the target EGR rate parameter value and the engine's air-fuel ratio limiting EGR rate parameter value is determined as the intermediate EGR rate parameter value.

[0086] When the operating condition is a mild acceleration condition, the smaller of the target EGR rate parameter value and the air-fuel ratio limiting EGR rate parameter value is determined as the intermediate EGR rate parameter value, wherein the air-fuel ratio limiting EGR rate parameter value is calculated based on the current engine speed and torque.

[0087] In this embodiment, the vehicle's ECU can obtain the current actual boost pressure through a pressure sensor in the boost system, and determine the current operating condition of the engine based on the actual boost pressure.

[0088] On the one hand, when the engine is under rapid acceleration, the target EGR rate parameter value corresponding to the current engine speed and current engine torque is compared with the engine air-fuel ratio limiting EGR rate parameter value, and the larger parameter value between the target EGR rate parameter value corresponding to the current engine speed and current engine torque and the engine air-fuel ratio limiting EGR rate parameter value is determined as the intermediate EGR rate parameter value.

[0089] On the other hand, when the engine is under mild acceleration conditions, the target EGR rate parameter value corresponding to the current engine speed and current engine torque is compared with the engine air-fuel ratio limiting EGR rate parameter value. The smaller of the two values ​​is determined as the intermediate EGR rate parameter value. The air-fuel ratio limiting EGR rate parameter value is calculated based on the current engine speed and torque, and the specific calculation method is as described in the above steps, which will not be repeated here.

[0090] In practical applications, when the engine is in steady-state operation, the amount of fresh air supplied by the engine meets the actual demand. That is, the engine's turbocharging system has enough time to build up the boost pressure. Therefore, when the engine is in steady-state operation, the air-fuel ratio limit is not triggered, and the EGR rate parameter value is taken according to the requirements of the original EGR rate demand spectrum.

[0091] Further, obtaining the current actual boost pressure of the engine and determining the current operating condition of the engine based on the actual boost pressure includes:

[0092] Based on the current engine speed and torque, determine the current required boost pressure of the engine;

[0093] If the difference between the actual boost pressure and the required boost pressure is greater than a first pressure threshold, the current operating condition of the engine is determined to be a rapid acceleration condition.

[0094] If the difference between the actual boost pressure and the required boost pressure is greater than or equal to a second pressure threshold, and less than or equal to a first pressure threshold, the current operating condition of the engine is determined to be a mild acceleration condition.

[0095] In this embodiment, the required boost pressure corresponding to the current engine speed and torque can be obtained. The current required boost pressure is compared with the current actual boost pressure. If the difference between the actual and required boost pressures is greater than a first pressure threshold, the engine is determined to be in a rapid acceleration condition. If the difference is greater than or equal to a second pressure threshold and less than or equal to the first pressure threshold, the engine is determined to be in a mild acceleration condition. In practical applications, if the difference between the actual and required boost pressures is greater than or equal to 0 and less than the second threshold pressure, the engine is determined to be in a steady-state condition. It should be noted that the first and second pressure thresholds are values ​​calibrated through numerous experiments. These thresholds may differ for different engine models, and this application does not impose any specific limitations on them.

[0096] Step S104: Compare the intermediate EGR rate parameter value with the original EGR rate parameter value of the engine to determine the required EGR rate value.

[0097] In this embodiment of the application, the intermediate EGR rate parameter value is compared with the original EGR rate parameter value of the engine to determine the required EGR rate value, specifically including the following methods:

[0098] Based on the current engine speed and torque, obtain the original EGR rate parameter value;

[0099] The intermediate EGR rate parameter value is compared with the original EGR rate parameter value, and the smaller of the intermediate EGR rate parameter value and the original EGR rate parameter value is determined as the EGR rate requirement value.

[0100] Specifically, based on the engine's current speed and torque, the original EGR rate parameter value is obtained. By querying a preset original EGR rate demand pulse spectrum, the original EGR rate parameter value corresponding to the current engine speed and torque is obtained. The original EGR rate demand pulse spectrum represents the mapping relationship between engine speed and torque and the original EGR rate parameter value. In practical applications, the engine's original EGR rate demand pulse spectrum is calibrated based on the engine's theoretical speed and torque. That is, based on different theoretical speeds and torques, corresponding original EGR rate parameter values ​​are calibrated, and finally, the original EGR rate demand pulse spectrum is obtained based on the original EGR rate parameter values ​​corresponding to different theoretical speeds and torques.

[0101] The obtained intermediate EGR rate parameter value is compared with the original EGR rate parameter value, and the smaller of the intermediate EGR rate parameter value and the original EGR rate parameter value is determined as the EGR rate requirement value.

[0102] This application obtains an EGR rate requirement value by comparing an intermediate EGR rate parameter value determined based on a target EGR rate parameter value and an engine air-fuel ratio-limited EGR rate parameter value with the engine's original EGR rate parameter value. This allows the engine to effectively reduce NOx emissions when operating at this EGR rate requirement value.

[0103] In a preferred embodiment of this application, a flowchart of a process for determining the EGR rate parameter value is provided, such as... Figure 2 As shown:

[0104] First, based on the current engine speed and torque, the target EGR rate parameter value corresponding to the current engine speed and torque is obtained by querying the minimum EGR rate limit pulse spectrum. Simultaneously, based on the current engine speed and torque, the engine's air-fuel ratio limit EGR rate parameter value is calculated. Then, based on the engine's current operating condition, the EGR rate parameter value corresponding to that condition is determined. Specifically, when the engine is currently in a rapid acceleration phase, the larger of the engine's air-fuel ratio limit EGR rate parameter value and the target EGR rate parameter value is determined as the intermediate EGR rate parameter value; when the engine is currently in a mild acceleration phase, the smaller of the engine's air-fuel ratio limit EGR rate parameter value and the target EGR rate parameter value is determined as the intermediate EGR rate parameter value.

[0105] Furthermore, based on the current engine speed and current engine torque, the original EGR rate parameter value corresponding to the current engine speed and current engine torque is determined by querying the original EGR rate demand spectrum of the engine, and the smaller of the original EGR rate parameter value and the intermediate EGR rate parameter value is determined as the EGR rate demand value.

[0106] In another preferred embodiment of this application, a schematic diagram of engine operating conditions is provided, such as... Figure 3 As shown: Region A represents a low-load region, and Region B represents a high-load region.

[0107] Under rapid acceleration, the engine instantly transitions from a low-load to a high-load region, such as... Figure 3As shown, the engine instantly transitions from region A to region B. During this transition, the operating conditions change drastically, and the boost pressure builds up slowly, resulting in the air-fuel ratio limiting the EGR rate parameter value. In region B, the engine's NOx emissions are high, while the smoke opacity is low. Therefore, in region B, by controlling the engine to operate at the EGR rate requirement value for rapid acceleration conditions determined in this embodiment, NOx emissions can be effectively reduced without causing further deterioration of smoke opacity.

[0108] Under mild acceleration conditions, the engine transitions from a low-load to a high-load region, such as... Figure 3 As shown in the transition zone from region A to region B, the engine's operating conditions change slightly during this transition zone. However, the build-up pressure is still slow, leading to a situation where the air-fuel ratio limits the EGR rate parameter value. In the transition zone from region A to region B, the engine's NOx emissions and smoke opacity are moderate. Therefore, by controlling the engine to operate at the EGR rate requirement value under stable acceleration conditions determined in this application embodiment during the transition zone from region A to region B, further increases in NOx emissions and further deterioration of smoke opacity can be avoided.

[0109] In another preferred embodiment of this application, a flowchart for determining the EGR rate parameter value is provided, such as... Figure 4 As shown:

[0110] First, obtain the engine's current required boost pressure and actual boost pressure, and calculate the difference ΔP between them. Determine if ΔP is less than a second pressure threshold. If so, the engine is determined to be in steady-state operation, and the EGR rate requirement value is determined using the original EGR rate requirement spectrum. If not, further determine if ΔP is greater than or equal to the second pressure threshold and less than or equal to the first pressure threshold. If so, the engine is determined to be in a mild acceleration condition, and the smaller of the air-fuel ratio limiting EGR rate parameter value and the target EGR rate parameter value is determined as the intermediate EGR rate parameter value. If not, the engine is determined to be in a rapid acceleration condition, and the larger of the air-fuel ratio limiting EGR rate parameter value and the target EGR rate parameter value is determined as the intermediate EGR rate parameter value. Compare the intermediate EGR rate parameter value with the original EGR rate parameter value, and determine the smaller of the two as the EGR rate requirement value.

[0111] This application provides a method for determining an EGR rate parameter value. The method includes: acquiring the current engine speed and torque; acquiring a target EGR rate parameter value corresponding to the current engine speed and torque; determining an intermediate EGR rate parameter value based on the target EGR rate parameter value and the engine's air-fuel ratio limiting EGR rate parameter value; and comparing the intermediate EGR rate parameter value with the engine's original EGR rate parameter value to determine an EGR rate requirement value. This application obtains the EGR rate requirement value by comparing the intermediate EGR rate parameter value determined based on the target EGR rate parameter value and the engine's air-fuel ratio limiting EGR rate parameter value with the engine's original EGR rate parameter value. This allows for effective reduction of NOx emissions when the engine operates at this EGR rate requirement value.

[0112] Based on the same inventive concept, a second aspect of the embodiments of this application provides a system for determining the value of an EGR rate parameter, such as... Figure 5 As shown, the system includes:

[0113] The first acquisition module 201 is used to acquire the current engine speed and torque;

[0114] The second acquisition module 202 is used to acquire the target EGR rate parameter value corresponding to the engine speed and torque based on the current engine speed and torque.

[0115] The first determining module 203 is used to determine an intermediate EGR rate parameter value based on the target EGR rate parameter value and the air-fuel ratio limiting EGR rate parameter value of the engine.

[0116] The second determining module 204 is used to compare the intermediate EGR rate parameter value with the original EGR rate parameter value of the engine to determine the EGR rate requirement value.

[0117] Optionally, the step of comparing the intermediate EGR rate parameter value with the original EGR rate parameter value of the engine to determine the EGR rate requirement value, the second determining module 204, includes:

[0118] The first acquisition submodule is used to acquire the original EGR rate parameter value based on the current engine speed and torque;

[0119] The first determining submodule is used to compare the intermediate EGR rate parameter value with the original EGR rate parameter value, and determine the smaller of the intermediate EGR rate parameter value and the original EGR rate parameter value as the EGR rate requirement value.

[0120] Optionally, the first determining module 203, which determines the intermediate EGR rate parameter value based on the target EGR rate parameter value and the engine's air-fuel ratio-limited EGR rate parameter value, includes:

[0121] The second acquisition submodule is used to acquire the current actual boost pressure of the engine and determine the current operating condition of the engine based on the actual boost pressure.

[0122] The second determining submodule is used to determine the larger of the target EGR rate parameter value and the engine's air-fuel ratio limiting EGR rate parameter value as the intermediate EGR rate parameter value when the operating condition is a rapid acceleration condition.

[0123] The third determining submodule is used to determine the smaller of the target EGR rate parameter value and the air-fuel ratio limiting EGR rate parameter value as the intermediate EGR rate parameter value when the operating condition is a mild acceleration condition. The air-fuel ratio limiting EGR rate parameter value is calculated based on the current engine speed and torque.

[0124] Optionally, the second acquisition submodule, which acquires the current actual boost pressure of the engine and determines the current operating condition of the engine based on the actual boost pressure, includes:

[0125] The first determining subunit is used to determine the current required boost pressure of the engine based on the current engine speed and torque.

[0126] The second determining subunit is used to determine that the current operating condition of the engine is a rapid acceleration condition when the difference between the actual boost pressure and the required boost pressure is greater than a first pressure threshold.

[0127] The third determining subunit is used to determine that the current operating condition of the engine is a mild acceleration condition when the difference between the actual boost pressure and the required boost pressure is greater than or equal to a second pressure threshold and less than or equal to the first pressure threshold.

[0128] Optionally, the second acquisition module 202, which acquires the target EGR rate parameter value corresponding to the current engine speed and torque, includes:

[0129] The third acquisition submodule is used to query a preset minimum EGR rate limit pulse spectrum based on the current engine speed and torque, and obtain the target EGR rate parameter value corresponding to the engine speed and torque, wherein the minimum EGR rate limit pulse spectrum represents the mapping relationship between the engine speed and torque and the target EGR rate parameter value.

[0130] Optionally, the first acquisition submodule, which obtains the original EGR rate parameter value based on the current engine speed and torque, includes:

[0131] The first acquisition subunit is used to query a preset original EGR rate demand pulse spectrum based on the current engine speed and torque, and obtain the original EGR rate parameter value corresponding to the engine speed and torque, wherein the original EGR rate demand pulse spectrum represents the mapping relationship between the engine speed and torque and the original EGR rate parameter value.

[0132] Optionally, the third determining submodule calculates the air-fuel ratio limiting EGR rate parameter value based on the current engine speed and torque, and includes:

[0133] The second acquisition subunit is used to acquire the current air-fuel ratio of the engine;

[0134] The fourth determining subunit is used to determine the minimum air-fuel ratio limit and the maximum air-fuel ratio limit corresponding to the current engine speed and torque.

[0135] The fifth determining subunit is used to determine the air-fuel ratio limit EGR rate parameter value based on the air-fuel ratio, the minimum air-fuel ratio limit, and the maximum air-fuel ratio limit.

[0136] Based on the same inventive concept, a third aspect of the embodiments of this application provides an electronic device 100, such as... Figure 6 As shown, the device includes a memory 110, a processor 120, and a computer program stored on the memory 110. The processor 120 executes the computer program to implement the method for determining the EGR rate parameter value as described in the first aspect of this application.

[0137] Based on the same inventive concept, in a fourth aspect of this application, a vehicle is provided, the vehicle including electronic equipment as described in the third aspect of this application.

[0138] Each embodiment in this specification focuses on the differences from other embodiments. For the same or similar parts between the embodiments, please refer to each other.

[0139] Those skilled in the art will understand that embodiments of this application can be provided as methods, apparatus, or computer program products. Therefore, embodiments of this application can take the form of entirely hardware embodiments, entirely software embodiments, or embodiments combining software and hardware aspects. Furthermore, embodiments of this application can take the form of computer program products implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0140] This application describes embodiments with reference to flowchart illustrations and / or block diagrams of methods, terminal devices (systems), and computer program products according to embodiments of this application. It should be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing terminal device to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing terminal device, generate instructions for implementing the flowchart illustrations. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0141] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing terminal device to operate in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0142] These computer program instructions can also be loaded onto a computer or other programmable data processing terminal equipment, causing a series of operational steps to be performed on the computer or other programmable terminal equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable terminal equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0143] Although preferred embodiments of the present application have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of the embodiments of the present application.

[0144] Finally, it should be noted that in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or terminal device that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or terminal device. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or terminal device that includes said element.

[0145] The above provides a detailed description of the method, system, electronic device, and vehicle for determining the EGR rate parameter value. Specific examples have been used to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A method for determining the EGR rate parameter value, characterized in that, The method includes: Obtain the current engine speed and torque; Based on the current engine speed and torque, obtain the target EGR rate parameter value corresponding to the engine speed and torque; Based on the target EGR rate parameter value and the engine's air-fuel ratio limiting EGR rate parameter value, an intermediate EGR rate parameter value is determined; The intermediate EGR rate parameter value is compared with the original EGR rate parameter value of the engine to determine the required EGR rate value; The step of obtaining the target EGR rate parameter value corresponding to the current engine speed and torque includes: Based on the current engine speed and torque, query the preset minimum EGR rate limit pulse spectrum to obtain the target EGR rate parameter value corresponding to the engine speed and torque; The step of determining the intermediate EGR rate parameter value based on the target EGR rate parameter value and the engine's air-fuel ratio-limited EGR rate parameter value includes: Obtain the current actual boost pressure of the engine, and determine the current operating condition of the engine based on the actual boost pressure; When the operating condition is a rapid acceleration condition, the larger of the target EGR rate parameter value and the engine's air-fuel ratio limiting EGR rate parameter value is determined as the intermediate EGR rate parameter value. When the operating condition is a mild acceleration condition, the smaller of the target EGR rate parameter value and the air-fuel ratio limiting EGR rate parameter value is determined as the intermediate EGR rate parameter value. The step of comparing the intermediate EGR rate parameter value with the original EGR rate parameter value of the engine to determine the EGR rate requirement value includes: Based on the current engine speed and torque, the preset original EGR rate demand pulse spectrum is queried to obtain the original EGR rate parameter value corresponding to the engine speed and torque.

2. The method for determining the EGR rate parameter value according to claim 1, characterized in that, The step of comparing the intermediate EGR rate parameter value with the original EGR rate parameter value of the engine to determine the EGR rate requirement value includes: The intermediate EGR rate parameter value is compared with the original EGR rate parameter value, and the smaller of the intermediate EGR rate parameter value and the original EGR rate parameter value is determined as the EGR rate requirement value.

3. The method for determining the EGR rate parameter value according to claim 1, characterized in that, The step of obtaining the current actual boost pressure of the engine and determining the current operating condition of the engine based on the actual boost pressure includes: Based on the current engine speed and torque, determine the current required boost pressure of the engine; If the difference between the actual boost pressure and the required boost pressure is greater than a first pressure threshold, the current operating condition of the engine is determined to be a rapid acceleration condition. If the difference between the actual boost pressure and the required boost pressure is greater than or equal to a second pressure threshold, and less than or equal to a first pressure threshold, the current operating condition of the engine is determined to be a mild acceleration condition.

4. The method for determining the EGR rate parameter value according to claim 1, characterized in that, The air-fuel ratio limiting EGR rate parameter value is calculated based on the current engine speed and torque, including: Obtain the current air-fuel ratio of the engine; Based on the current engine speed and torque, determine the minimum air-fuel ratio limit and the maximum air-fuel ratio limit corresponding to the engine speed and torque; The air-fuel ratio limit EGR rate parameter value is determined based on the air-fuel ratio, the minimum air-fuel ratio limit, and the maximum air-fuel ratio limit.

5. A system for determining the value of an EGR rate parameter, characterized in that, The system includes: The first acquisition module is used to acquire the current engine speed and torque; The second acquisition module is used to acquire the target EGR rate parameter value corresponding to the engine speed and torque based on the current engine speed and torque. The first determining module is used to determine an intermediate EGR rate parameter value based on the target EGR rate parameter value and the air-fuel ratio limiting EGR rate parameter value of the engine. The second determining module is used to compare the intermediate EGR rate parameter value with the original EGR rate parameter value of the engine to determine the EGR rate requirement value. The second acquisition module includes: The third acquisition submodule is used to query the preset minimum EGR rate limit pulse spectrum based on the current engine speed and torque, and obtain the target EGR rate parameter value corresponding to the engine speed and torque. The first determining module includes: The second acquisition submodule is used to acquire the current actual boost pressure of the engine and determine the current operating condition of the engine based on the actual boost pressure. The second determining submodule is used to determine the larger of the target EGR rate parameter value and the engine's air-fuel ratio limiting EGR rate parameter value as the intermediate EGR rate parameter value when the operating condition is a rapid acceleration condition. The third determining submodule is used to determine the smaller of the target EGR rate parameter value and the air-fuel ratio limiting EGR rate parameter value as the intermediate EGR rate parameter value when the operating condition is mild acceleration condition. The second determining module includes: The first acquisition subunit is used to query a preset original EGR rate demand pulse spectrum based on the current engine speed and torque, and obtain the original EGR rate parameter value corresponding to the engine speed and torque.

6. An electronic device comprising a memory, a processor, and a computer program stored in the memory, characterized in that, The processor executes the computer program to implement the method for determining the EGR rate parameter value as described in any one of claims 1 to 4.

7. A vehicle, characterized in that, The vehicle includes the electronic equipment as described in claim 6.

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