Fuel gas component self-adaptive control method, system and equipment and motor vehicle

Abstract

The invention relates to a fuel gas component self-adaptive control method, system and device and a motor vehicle. Knocking signals are obtained and converted into the average knocking intensity KN0; when the average knock intensity KN0 is smaller than or equal to the set knock intensity KN1, the air-fuel ratio Lam1 and the ignition angle ADV1 are obtained according to a preset first MAP curve, and the engine is controlled; the knock intensity KN1lt is set; the average knock intensity KN0lt; when the knock intensity KN2 is set, a corresponding air-fuel ratio and a corresponding ignition angle are obtained through interpolation processing, and an engine is controlled; and when the average knock intensity KN0 is larger than or equal to the set knock intensity KN2, a prompt signal is sent out, the corresponding air-fuel ratio Lam2 and the corresponding ignition angle ADV2 are determined according to a preset second MAP curve, and the engine is controlled. And two sets of control curves related to the fuel gas components are preset, the air-fuel ratio and the ignition advance angle are dynamically adjusted according to the obtained real-time knock intensity, so that stable operation of the engine is maintained, and the adaptability of the engine to fuel gas component changes is improved.

Description

Technical Field

[0001] This invention relates to the field of engine control technology, specifically to adaptive control methods, systems, equipment, and motor vehicles for gas composition. Background Technology

[0002] The statements in this section are merely background information related to the present invention and do not necessarily constitute prior art.

[0003] Knock (also known as detonation or knocking) is an abnormal combustion phenomenon in an engine. It refers to the phenomenon where, after normal ignition by the spark plug, unburned air-fuel mixture spontaneously combusts due to high temperature and pressure, forming multiple flame fronts and generating violent pressure fluctuations, resulting in a metallic knocking sound and a decrease in engine power.

[0004] For gas-fired engines (such as CNG natural gas and LPG liquefied petroleum gas), knocking is more likely to occur when the composition of the gas changes (such as gases with low methane content and high knocking tendency).

[0005] To address the knocking problem, a knock sensor is typically used to acquire the vibration signal when knocking occurs (some also use an in-cylinder pressure sensor and spark plug electrodes to detect it) to determine whether knocking has occurred. A gas composition detection sensor is used to acquire the changes in gas composition during knocking. Combined with a pre-set control strategy, the ECU is used to change the engine's ignition angle and air-fuel ratio to mitigate the knocking phenomenon.

[0006] Existing technology uses a fuel composition sensor to detect changes in fuel composition, enabling the ECU to adjust the ignition timing and air-fuel ratio in a timely manner. This ensures the engine can adapt to changes in fuel composition and proactively prevent or mitigate knocking caused by these changes. However, this method suffers from a response delay. When fuel composition changes abruptly, there is a delay in the fuel composition sensor transmitting the information to the ECU. Similarly, there is a delay in the ECU receiving the signal and issuing corresponding control strategies, and in the process of controlling the engine to adjust the ignition timing and air-fuel ratio. This means that the engine may have already experienced the effects of knocking for some time before the problem is resolved.

[0007] Secondly, the changes in the gas composition are unknown. If the gas composition changes abruptly beyond the detection range of the gas composition sensor, it will trigger the ECU to activate the protection mode and forcibly reduce the engine power.

[0008] In summary, the method of adding a gas composition sensor is not ideal for solving the knocking problem. Summary of the Invention

[0009] To address the technical problems mentioned above, this invention provides a method, system, device, and vehicle for adaptive control of fuel gas composition. It presets two sets of control curves related to fuel gas composition and dynamically adjusts the air-fuel ratio and ignition advance angle based on the real-time knock intensity obtained from the knock sensor to maintain stable engine operation, thereby improving the engine's adaptability to changes in fuel gas composition.

[0010] To achieve the above objectives, the present invention adopts the following technical solution: The first aspect of the present invention provides a method for adaptive control of gas composition, comprising the following steps: Acquire the detonation signal and convert it into the average detonation intensity KN0; When the average knock intensity KN0 ≤ the set knock intensity KN1, the air-fuel ratio Lam1 and ignition angle ADV1 are obtained according to the preset first MAP curve to control the engine. When the set knock intensity KN1 < average knock intensity KN0 < set knock intensity KN2, the corresponding air-fuel ratio and ignition angle are obtained through interpolation to control the engine. When the average knock intensity KN0 is greater than or equal to the set knock intensity KN2, a warning signal is issued, and the corresponding air-fuel ratio Lam2 and ignition angle ADV2 are determined and the engine is controlled according to the preset second MAP curve. The first MAP curve is formed by simulating the engine running under natural gas composition and using the obtained average knock intensity KN1, air-fuel ratio Lam1 and ignition angle ADV1. The second MAP curve is obtained by simulating the engine operating with a methane content lower than that of natural gas. During this period, the air-fuel ratio Lam1 or the ignition angle ADV1 is selected to obtain the corresponding average knock intensity KN2. The engine state is adjusted with KN2≈KN1 as the target to obtain the air-fuel ratio Lam2 and the ignition angle ADV2, thus forming the second MAP curve.

[0011] Furthermore, the process of obtaining the first MAP curve is as follows: through bench testing, the engine is simulated to operate under the combustion gas composition Comp1, and the corresponding average knock intensity KN1, air-fuel ratio Lam1 and ignition angle ADV1 are obtained during the operation. The average knock intensity KN1 is normalized to form the first MAP curve corresponding to the combustion gas composition Comp1.

[0012] Furthermore, the gas component Comp1 is natural gas or a simulated gas with a composition similar to natural gas during the experiment.

[0013] Furthermore, the process of obtaining the second MAP curve is as follows: through bench testing, the engine is simulated to operate under the combustion gas composition Comp2. During this process, the air-fuel ratio Lam1 or the ignition angle ADV1 in the first MAP curve is selected to obtain the corresponding average knock intensity KN2 and normalize it. The engine state is adjusted with KN2≈KN1 as the target to obtain the air-fuel ratio Lam2 and the ignition angle ADV2. The experimental data is then fitted to obtain the second MAP curve corresponding to the combustion gas composition Comp2.

[0014] Furthermore, the detonation tendency of the gas component Comp2 is higher than that of the gas component Comp1, and the methane content in Comp2 is lower than that in the gas component Comp1, including at least hydrogen-doped methane or methane containing associated gas.

[0015] Furthermore, in the first MAP curve and the second MAP curve, the air-fuel ratio Lam1 is less than the air-fuel ratio Lam2 for the same operating condition, and the ignition angle ADV1 is greater than the ignition angle ADV2.

[0016] Furthermore, when the average knock intensity KN0 ≥ KN2 ​​and rises to exceed the safety limit, an alarm signal is issued and the engine is switched to a safe mode.

[0017] A second aspect of the present invention provides a gas composition adaptive control system, comprising: The detonation signal acquisition module is configured to acquire detonation signals and convert them into average detonation intensity KN0. The engine control module is configured to control the engine when the average knock intensity KN0 ≤ set knock intensity KN1, based on the preset first MAP curve to obtain the air-fuel ratio Lam1 and ignition angle ADV1. The engine control module is also configured to: when the average knock intensity KN1 < average knock intensity KN0 < set knock intensity KN2, obtain the corresponding air-fuel ratio and ignition angle through interpolation to control the engine; The engine control module is also configured to issue a warning signal when the average knock intensity KN0 ≥ the set knock intensity KN2, and determine the corresponding air-fuel ratio Lam2 and ignition angle ADV2 according to the preset second MAP curve and control the engine. The first MAP curve is formed by simulating the engine running under natural gas composition and using the obtained average knock intensity KN1, air-fuel ratio Lam1 and ignition angle ADV1. The second MAP curve is obtained by simulating the engine operating with a methane content lower than that of natural gas. During this period, the air-fuel ratio Lam1 or the ignition angle ADV1 is selected to obtain the corresponding average knock intensity KN2. The engine state is adjusted with KN2≈KN1 as the target to obtain the air-fuel ratio Lam2 and the ignition angle ADV2, thus forming the second MAP curve.

[0018] A third aspect of the present invention provides a computer program product including computer-readable instructions that, when executed on an electronic device, cause the electronic device to implement the above-described adaptive control method for gas composition.

[0019] A fourth aspect of the present invention provides an electronic device comprising at least one processor and a memory connected to the processor, the memory being used to store a computer program; the processor being used to execute the computer program, enabling the electronic device to implement the above-described adaptive control method for gas composition.

[0020] A fifth aspect of the present invention provides a motor vehicle having an on-board control unit, wherein the steps in the above-described adaptive control method for gas composition are executed by the on-board control unit.

[0021] Compared with existing technologies, one or more of the above technical solutions have the following beneficial effects: 1. By presetting two sets of control curves related to the composition of the combustion gas, the curves cover the correspondence between the set composition of the combustion gas, the average knock intensity threshold, the air-fuel ratio, and the ignition angle. Based on the real-time knock intensity obtained by the knock sensor, the air-fuel ratio and ignition angle are dynamically adjusted according to the corresponding control curves to maintain stable engine operation, thereby improving the engine's adaptability to changes in the composition of the combustion gas.

[0022] 2. During control, fuel characteristics can be inferred from the knock intensity reflected in the engine's real-time combustion status, eliminating the need for existing fuel composition sensors. Adjustment is achieved solely through knock feedback, making it suitable for conditions involving unknown fuels and sudden fuel changes. Reducing the number of sensors used lowers hardware costs and mitigates the negative impact of response delays, thereby enhancing the engine's ability to adapt to different fuel compositions.

[0023] 3. The pre-determined MAP curves for the two components essentially define the air-fuel ratio and ignition angle corresponding to the ideal combustion state, as well as the air-fuel ratio and ignition angle corresponding to the combustion state near its limit (before the methane content falls below a certain limit, the engine can still operate without major malfunctions). These two sets of MAP curves cover a relatively wide control range, allowing the engine to find the corresponding air-fuel ratio and ignition angle during operation, regardless of methane content, as long as the knock signal is detectable and covered by both sets of MAP curves. This enables adaptive adjustment and compatibility with any combustion mixture ratio. When the combustion state falls between the two sets of MAP curves, interpolation is used for a smooth transition, avoiding abrupt parameter changes and achieving gradual adjustment with higher stability.

[0024] 4. In practical applications, some gas engines may be modified from gasoline engines. Knock sensors are standard components, but gas composition detection sensors are not. This solution can reuse existing sensors. The relevant parameters in the two sets of MAP curves can be reused after pre-calibration. When different gases are mixed into the gas to form new fuels, the calibrated parameters can be reused without recalibration. Attached Figure Description

[0025] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0026] Figure 1 This is a schematic diagram of the overall process of adaptive control of gas composition provided by one or more embodiments of the present invention; Figure 2 This is a schematic diagram of the adaptive control of gas composition provided in one or more embodiments of the present invention. Detailed Implementation

[0027] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0028] It should be noted that the following detailed descriptions are exemplary and intended to provide further illustration of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0029] It should be noted that the terminology used herein is for the purpose of describing particular implementations only and is not intended to limit the scope of exemplary embodiments of the invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms “comprising” and / or “including” are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0030] The knocking principle of a gas engine is the same as that of a gasoline engine. After the gas (such as CNG natural gas or LPG liquefied petroleum gas) is ignited by the spark plug in the cylinder, if the unburned mixture spontaneously combusts due to high temperature and pressure, it will still cause knocking, producing shock waves and metallic knocking sounds.

[0031] Changes in the composition of fuel gas can affect detonation. For example, the higher the proportion of methane in the fuel gas, the better its anti-knock properties. The presence of impurities (such as sulfides) may reduce stability.

[0032] The vibrations generated when knock occurs impact various engine components, which can easily cause mechanical damage. Secondly, after the ECU detects knock, it will actively delay the ignition timing, resulting in decreased combustion efficiency and reduced torque. Furthermore, the incomplete combustion caused by the delayed ignition timing will worsen fuel economy and increase fuel consumption.

[0033] The following embodiments provide a method, system, device, and vehicle for adaptive control of fuel gas composition. Two sets of control curves related to fuel gas composition are preset. The real-time knock intensity obtained by the knock sensor within a set time period is averaged to obtain KN. The air-fuel ratio (Lam) and ignition advance angle (ADV) are dynamically adjusted to maintain stable engine operation, thereby improving the engine's adaptability to changes in fuel gas composition.

[0034] Example 1: like Figure 1 As shown, the adaptive control method for gas composition includes the following steps: Acquire the detonation signal and convert it into the average detonation intensity KN0; When the average knock intensity KN0 ≤ the set knock intensity KN1, the air-fuel ratio Lam1 and ignition angle ADV1 are obtained according to the preset first MAP curve, and the engine is controlled. When the set knock intensity KN1 < average knock intensity KN0 < set knock intensity KN2, the corresponding air-fuel ratio and ignition angle are obtained through interpolation, and the engine is controlled. When the average knock intensity KN0 is greater than or equal to the set knock intensity KN2, a warning signal is issued. Based on the preset second MAP curve, the corresponding air-fuel ratio Lam2 and ignition angle ADV2 are determined, and the engine is controlled.

[0035] in: The first MAP curve is: by simulating the engine running under the gas composition Comp1 through bench tests, the average knock intensity KN1, air-fuel ratio Lam1 and ignition angle ADV1 are used to form the first MAP curve corresponding to the gas composition Comp1. The second MAP curve is obtained by simulating engine operation under combustion gas composition Comp2 through bench testing. The air-fuel ratio Lam1 or ignition angle ADV1 in the first MAP curve is selected to obtain the corresponding average knock intensity KN2. By adjusting the air-fuel ratio Lam2 and ignition angle ADV2, KN2≈KN1 is made, and the experimental data is fitted to obtain the second MAP curve corresponding to combustion gas composition Comp2. Combustion gas composition Comp1 is natural gas, and combustion gas composition Comp2 is low-quality gas with low methane number and high knock tendency, such as hydrogen-blended or associated gas.

[0036] A normalized table of knock intensity signals was pre-constructed. Specifically, the average knock intensity at various engine speeds and intake manifold pressures was normalized through bench tests. The results are shown in Table 1, with the first row representing engine speed in r / min and the first column representing intake manifold pressure in kPa.

[0037] Table 1: Normalized Table of Knock Intensity Signals

[0038] Two gas compositions, Comp1 and Comp2, are pre-defined. Comp1 is similar to natural gas, while Comp2 represents a gas with a low methane number and high knocking tendency, such as one mixed with hydrogen or associated gas, and its methane number is lower than that of Comp1.

[0039] Under Comp1 composition, the corresponding average knock intensity was calibrated as KN1, the corresponding air-fuel ratio as Lam1, and the corresponding ignition angle as ADV1 through bench tests. The average knock intensity KN1 was normalized using the baseline operating conditions, and all the data obtained formed the MAP curve of KN1-Lam1-ADV1 under Comp1 composition.

[0040] Average knock intensity: Assuming the engine has N cylinders, the average knock intensity is obtained by dividing the knock intensity of all cylinders by N over several combustion cycles.

[0041] Bench tests were conducted with Comp2 composition. Using the air-fuel ratio Lam1 or ignition angle ADV1 corresponding to Comp1 composition, a high knock signal was generated. The obtained knock signal was averaged and normalized to obtain the average knock intensity KN2.

[0042] Bench tests were continued with the Comp2 composition. By continuously adjusting the air-fuel ratio Lam2 and the ignition angle ADV2, the normalized average knock intensity KN2≈KN1 was achieved. The experimental data were fitted to form the MAP curve of KN2-Lam2-ADV2 for the Comp2 composition.

[0043] In both sets of MAP curves, under the same operating condition, the air-fuel ratio Lam1 is smaller than Lam2, and the ignition angle ADV1 is larger than ADV2. Because Comp1 has better anti-knock properties, allowing for a richer mixture (stronger power performance), Lam1 is richer; secondly, Comp1 can withstand a larger ignition advance angle (optimizing efficiency), thus ADV1 is larger. Comp2, on the other hand, needs to dilute the fuel to lower the combustion temperature and suppress knock, therefore Lam2 is leaner; simultaneously, Comp2 needs to delay ignition to avoid end-gas auto-ignition, thus ADV2 is smaller.

[0044] The MAP curves corresponding to Component Comp1 and Component Comp2 are obtained through bench tests. The data is accurate and can directly reflect the characteristics of Component Comp2. The knocking intensity KN of the gas using Component Comp2 will be on the high side. It is adjusted down by modifying the parameters. Finally, when the KN read by the ECU is on the high side, it shifts to the curves of Lam (air-fuel ratio) and ADV (ignition angle) corresponding to KN2 set in this solution.

[0045] After obtaining the MAP curves corresponding to Component Comp1 and Component Comp2, according to Figure 2 the process shown, to address the knocking problem when the gas changes, it includes the following steps: Obtain the knocking signal and convert it into the average knocking intensity KN0; When the average knocking intensity KN0 ≤ KN1, according to the MAP curve of Component Comp1, determine the corresponding air-fuel ratio Lam1 and ignition angle ADV1, and perform the adjustment of the air-fuel ratio and ignition angle to address the knocking problem; When KN1 < average knocking intensity KN0 < KN2, perform interpolation processing on the current air-fuel ratio and ignition angle of the engine; specifically: linearly interpolate according to KN0 between (Lam1, ADV1) and (Lam2, ADV2), and gradually correct to determine the air-fuel ratio and ignition angle corresponding to the corrected KN0; When the average knocking intensity KN0 ≥ KN2, send a prompt signal to prompt the user that the current knocking intensity of the engine is too high and the fuel gas composition needs to be checked; and according to the MAP curve of Component Comp2, determine the corresponding air-fuel ratio Lam2 and ignition angle ADV2, and perform the adjustment of the air-fuel ratio and ignition angle to address the knocking problem.

[0046] When the average knocking intensity KN0 continues to rise beyond the safety limit, send an alarm signal and switch to the safety mode. In the safety mode, the power is reduced by restricting the maximum throttle opening.

[0047] In the above process, at the initial state, the engine preferentially addresses the knocking problem according to the MAP curve of Component Comp1, and continuously obtains the knocking signal and calculates the average knocking intensity during this period. As the average knocking intensity gradually increases, the air-fuel ratio and ignition angle are adjusted successively according to the "MAP curve of Component Comp1", "interpolation processing of the MAP curves of Component Comp1 and Component Comp2", and the "MAP curve of Component Comp2". When the average knocking intensity exceeds the safety limit, it is considered that knocking has occurred, and then it switches to the safety mode.

[0048] Interpolation processing, for example: when the current KN0 = (KN1 + KN2) / 2, then the air-fuel ratio Lam = (Lam1 + Lam2) / 2; the ignition angle ADV = (ADV1 + ADV2) / 2.

[0049] When the vehicle is stopped, the current average knock intensity KN0 is saved. The next time the vehicle is run, the corresponding air-fuel ratio and ignition angle are first looked up based on the saved average knock intensity.

[0050] The aforementioned method can suppress knock by dynamically adjusting the air-fuel ratio and ignition advance angle when the combustion gas composition is unknown or fluctuating. Since it does not rely on combustion gas composition detection, fuel characteristics can be inferred from the engine's real-time combustion status. It eliminates the need for existing combustion gas composition sensors, relying solely on knock feedback for adjustment, making it suitable for operating conditions involving unknown fuels and sudden fuel changes. Reducing the number of sensors used lowers hardware costs and mitigates the negative impact of response latency, thus improving the engine's ability to adapt to different combustion gas compositions.

[0051] It is compatible with any gas-fuel mixture ratio. The pre-defined MAP curves for the two components essentially set the air-fuel ratio and ignition angle corresponding to the ideal gas state, as well as the air-fuel ratio and ignition angle corresponding to the gas state near the limit (before the methane content is below a certain limit, the engine can still run without major failure). The two sets of MAP curves cover a relatively wide control range, allowing the engine to find the corresponding air-fuel ratio and ignition angle during operation, regardless of the methane content, as long as the knock signal is detectable and covered by the two sets of MAP curves, thus achieving adaptive adjustment. When the gas state is between Comp1 and Comp2, the transition is smoothed through interpolation, avoiding abrupt parameter changes and achieving gradual adjustment with higher stability.

[0052] In practical applications, some gas engines may be modified from gasoline engines, and knock sensors are standard components, while gas composition detection sensors are not. This solution can reuse existing sensors, and the relevant parameters in Comp1 and Comp2 can be reused after pre-calibration. When different gases are mixed into the gas to form new fuels, the calibrated parameters can be reused without recalibration.

[0053] Example 2: The gas composition adaptive control system includes: The detonation signal acquisition module is configured to acquire detonation signals and convert them into average detonation intensity KN0. The engine control module is configured to: when the average knock intensity KN0 ≤ the set knock intensity KN1, obtain the air-fuel ratio Lam1 and the ignition angle ADV1 according to the preset first MAP curve, and control the engine. The engine control module is also configured to: when the set knock intensity KN1 < average knock intensity KN0 < set knock intensity KN2, obtain the corresponding air-fuel ratio and ignition angle through interpolation, and control the engine; The engine control module is also configured to issue a warning signal when the average knock intensity KN0 ≥ the set knock intensity KN2, determine the corresponding air-fuel ratio Lam2 and ignition angle ADV2 according to the preset second MAP curve, and control the engine. The first MAP curve is formed by simulating the engine running under natural gas composition and using the obtained average knock intensity KN1, air-fuel ratio Lam1 and ignition angle ADV1. The second MAP curve is obtained by simulating the engine operating with a methane content lower than that of natural gas. During this period, the air-fuel ratio Lam1 or the ignition angle ADV1 is selected to obtain the corresponding average knock intensity KN2. The engine state is adjusted with KN2≈KN1 as the target to obtain the air-fuel ratio Lam2 and the ignition angle ADV2, thus forming the second MAP curve.

[0054] As a further implementation method, the process of obtaining the first MAP curve is as follows: through bench testing, the engine is simulated to operate under the combustion gas composition Comp1, and the corresponding average knock intensity KN1, air-fuel ratio Lam1 and ignition angle ADV1 during the operation are obtained. The average knock intensity KN1 is normalized to form the first MAP curve corresponding to the combustion gas composition Comp1.

[0055] As a further implementation, the gas component Comp1 is natural gas or a simulated gas with a composition similar to natural gas during the experiment.

[0056] As a further implementation method, the process of obtaining the second MAP curve is as follows: through bench testing, the engine is simulated to operate under the combustion gas composition Comp2. During the test, the air-fuel ratio Lam1 or the ignition angle ADV1 in the first MAP curve is selected to obtain the corresponding average knock intensity KN2 and normalize it. The state of the engine is adjusted with KN2≈KN1 as the target to obtain the air-fuel ratio Lam2 and the ignition angle ADV2. The experimental data is fitted to obtain the second MAP curve corresponding to the combustion gas composition Comp2.

[0057] As a further embodiment, the detonation tendency of the gas component Comp2 is higher than that of the gas component Comp1, and the methane content therein is lower than that of the gas component Comp1, including at least hydrogen-doped methane or methane containing associated gas.

[0058] As a further implementation, in the first MAP curve and the second MAP curve, the air-fuel ratio Lam1 corresponding to the same operating condition is less than the air-fuel ratio Lam2, and the ignition angle ADV1 is greater than the ignition angle ADV2.

[0059] As a further implementation, when the average knock intensity KN0 ≥ KN2 ​​and rises to a level exceeding the safety limit, an alarm signal is issued and the engine is switched to a safe mode.

[0060] By pre-setting two sets of control curves related to the composition of the combustion gas, which cover the correspondence between the set composition of the combustion gas, the average knock intensity threshold, the air-fuel ratio, and the ignition angle, the air-fuel ratio and ignition angle are dynamically adjusted according to the real-time knock intensity obtained by the knock sensor, based on the corresponding control curves, to maintain stable engine operation and thus improve the engine's adaptability to changes in the composition of the combustion gas.

[0061] Example 3: A computer program product includes computer-readable instructions that, when executed on an electronic device, cause the electronic device to implement the aforementioned adaptive control method for gas composition, comprising the following steps: Acquire the detonation signal and convert it into the average detonation intensity KN0; When the average knock intensity KN0 ≤ the set knock intensity KN1, the air-fuel ratio Lam1 and ignition angle ADV1 are obtained according to the preset first MAP curve to control the engine. When the set knock intensity KN1 < average knock intensity KN0 < set knock intensity KN2, the corresponding air-fuel ratio and ignition angle are obtained through interpolation to control the engine. When the average knock intensity KN0 is greater than or equal to the set knock intensity KN2, a warning signal is issued, and the corresponding air-fuel ratio Lam2 and ignition angle ADV2 are determined and the engine is controlled according to the preset second MAP curve. The first MAP curve is formed by simulating the engine running under natural gas composition and using the obtained average knock intensity KN1, air-fuel ratio Lam1 and ignition angle ADV1. The second MAP curve is obtained by simulating the engine operating with a methane content lower than that of natural gas. During this period, the air-fuel ratio Lam1 or the ignition angle ADV1 is selected to obtain the corresponding average knock intensity KN2. The engine state is adjusted with KN2≈KN1 as the target to obtain the air-fuel ratio Lam2 and the ignition angle ADV2, thus forming the second MAP curve.

[0062] By pre-setting two sets of control curves related to the composition of the combustion gas, which cover the correspondence between the set composition of the combustion gas, the average knock intensity threshold, the air-fuel ratio, and the ignition angle, the air-fuel ratio and ignition angle are dynamically adjusted according to the real-time knock intensity obtained by the knock sensor, based on the corresponding control curves, to maintain stable engine operation and thus improve the engine's adaptability to changes in the composition of the combustion gas.

[0063] Example 4: An electronic device includes at least one processor and a memory connected to the processor, the memory storing a computer program; the processor executes the computer program to enable the electronic device to implement the above-described adaptive control method for gas composition, comprising the following steps: Acquire the detonation signal and convert it into the average detonation intensity KN0; When the average knock intensity KN0 ≤ the set knock intensity KN1, the air-fuel ratio Lam1 and ignition angle ADV1 are obtained according to the preset first MAP curve to control the engine. When the set knock intensity KN1 < average knock intensity KN0 < set knock intensity KN2, the corresponding air-fuel ratio and ignition angle are obtained through interpolation to control the engine. When the average knock intensity KN0 is greater than or equal to the set knock intensity KN2, a warning signal is issued, and the corresponding air-fuel ratio Lam2 and ignition angle ADV2 are determined and the engine is controlled according to the preset second MAP curve. The first MAP curve is formed by simulating the engine running under natural gas composition and using the obtained average knock intensity KN1, air-fuel ratio Lam1 and ignition angle ADV1. The second MAP curve is obtained by simulating the engine operating with a methane content lower than that of natural gas. During this period, the air-fuel ratio Lam1 or the ignition angle ADV1 is selected to obtain the corresponding average knock intensity KN2. The engine state is adjusted with KN2≈KN1 as the target to obtain the air-fuel ratio Lam2 and the ignition angle ADV2, thus forming the second MAP curve.

[0064] By pre-setting two sets of control curves related to the composition of the combustion gas, which cover the correspondence between the set composition of the combustion gas, the average knock intensity threshold, the air-fuel ratio, and the ignition angle, the air-fuel ratio and ignition angle are dynamically adjusted according to the real-time knock intensity obtained by the knock sensor, based on the corresponding control curves, to maintain stable engine operation and thus improve the engine's adaptability to changes in the composition of the combustion gas.

[0065] Example 5: A motor vehicle has an on-board control unit, which executes the steps in the above-described adaptive control method for fuel composition, including the following steps: Acquire the detonation signal and convert it into the average detonation intensity KN0; When the average knock intensity KN0 ≤ the set knock intensity KN1, the air-fuel ratio Lam1 and ignition angle ADV1 are obtained according to the preset first MAP curve to control the engine. When the set knock intensity KN1 < average knock intensity KN0 < set knock intensity KN2, the corresponding air-fuel ratio and ignition angle are obtained through interpolation to control the engine. When the average knock intensity KN0 is greater than or equal to the set knock intensity KN2, a warning signal is issued, and the corresponding air-fuel ratio Lam2 and ignition angle ADV2 are determined and the engine is controlled according to the preset second MAP curve. The first MAP curve is formed by simulating the engine running under natural gas composition and using the obtained average knock intensity KN1, air-fuel ratio Lam1 and ignition angle ADV1. The second MAP curve is obtained by simulating the engine operating with a methane content lower than that of natural gas. During this period, the air-fuel ratio Lam1 or the ignition angle ADV1 is selected to obtain the corresponding average knock intensity KN2. The engine state is adjusted with KN2≈KN1 as the target to obtain the air-fuel ratio Lam2 and the ignition angle ADV2, thus forming the second MAP curve.

[0066] By pre-setting two sets of control curves related to the composition of the combustion gas, which cover the correspondence between the set composition of the combustion gas, the average knock intensity threshold, the air-fuel ratio, and the ignition angle, the air-fuel ratio and ignition angle are dynamically adjusted according to the real-time knock intensity obtained by the knock sensor, based on the corresponding control curves, to maintain stable engine operation and thus improve the engine's adaptability to changes in the composition of the combustion gas.

[0067] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for adaptive control of gas composition, characterized in that, Includes the following steps: Acquire the detonation signal and convert it into the average detonation intensity KN0; When the average knock intensity KN0 ≤ the set knock intensity KN1, the air-fuel ratio Lam1 and ignition angle ADV1 are obtained according to the preset first MAP curve to control the engine. When the set knock intensity KN1 < average knock intensity KN0 < set knock intensity KN2, the corresponding air-fuel ratio and ignition angle are obtained through interpolation to control the engine. When the average knock intensity KN0 is greater than or equal to the set knock intensity KN2, a warning signal is issued, and the corresponding air-fuel ratio Lam2 and ignition angle ADV2 are determined according to the preset second MAP curve and the engine is controlled. The first MAP curve is formed by simulating the engine running under natural gas composition and using the obtained average knock intensity KN1, air-fuel ratio Lam1 and ignition angle ADV1. The second MAP curve is obtained by simulating the engine operating with a methane content lower than that of natural gas. By selecting the air-fuel ratio Lam1 or the ignition angle ADV1, the corresponding average knock intensity KN2 is obtained. The engine state is adjusted with KN2≈KN1 as the target to obtain the air-fuel ratio Lam2 and the ignition angle ADV2, thus forming the second MAP curve.

2. The adaptive control method for gas composition as described in claim 1, characterized in that, The process of obtaining the first MAP curve is as follows: the engine is simulated to run under the combustion gas composition Comp1 through bench testing, and the corresponding average knock intensity KN1, air-fuel ratio Lam1 and ignition angle ADV1 are obtained during the operation. The average knock intensity KN1 is normalized to form the first MAP curve corresponding to the combustion gas composition Comp1.

3. The adaptive control method for gas composition as described in claim 2, characterized in that, The gas component Comp1 is natural gas or a simulated gas with a composition similar to natural gas during the experiment.

4. The adaptive control method for gas composition as described in claim 1, characterized in that, The process of obtaining the second MAP curve is as follows: Through bench testing, the engine is simulated to operate under the combustion gas composition Comp2. The air-fuel ratio Lam1 or the ignition angle ADV1 in the first MAP curve is selected to obtain the corresponding average knock intensity KN2 and normalize it. The state of the engine is adjusted with KN2≈KN1 as the target to obtain the air-fuel ratio Lam2 and the ignition angle ADV2. The experimental data is fitted to obtain the second MAP curve corresponding to the combustion gas composition Comp2.

5. The adaptive control method for gas composition as described in claim 4, characterized in that, The combustion gas component Comp2 has a higher knocking tendency than the combustion gas component Comp1, and its methane content is lower than that of the combustion gas component Comp1, including at least hydrogen-doped methane or methane containing associated gas.

6. The adaptive control method for gas composition as described in claim 1, characterized in that, In the first MAP curve and the second MAP curve, the air-fuel ratio Lam1 is less than the air-fuel ratio Lam2 and the ignition angle ADV1 is greater than the ignition angle ADV2 for the same operating condition.

7. The adaptive control method for gas composition as described in claim 1, characterized in that, When the average knock intensity KN0 ≥ KN2 ​​and rises to a level exceeding the safety limit, an alarm signal is issued and the engine is switched to safety mode.

8. A gas composition adaptive control system, characterized in that, include: The detonation signal acquisition module is configured to acquire detonation signals and convert them into average detonation intensity KN0. The engine control module is configured to: when the average knock intensity KN0 ≤ the set knock intensity KN1, obtain the air-fuel ratio Lam1 and the ignition angle ADV1 according to the preset first MAP curve, and control the engine. The engine control module is also configured to: when the average knock intensity KN1 < average knock intensity KN0 < set knock intensity KN2, obtain the corresponding air-fuel ratio and ignition angle through interpolation to control the engine; The engine control module is also configured to issue a warning signal when the average knock intensity KN0 ≥ the set knock intensity KN2, and determine the corresponding air-fuel ratio Lam2 and ignition angle ADV2 according to the preset second MAP curve and control the engine. The first MAP curve is formed by simulating the engine running under natural gas composition and using the obtained average knock intensity KN1, air-fuel ratio Lam1 and ignition angle ADV1. The second MAP curve is obtained by simulating the engine operating with a methane content lower than that of natural gas. During this period, the air-fuel ratio Lam1 or the ignition angle ADV1 is selected to obtain the corresponding average knock intensity KN2. The engine state is adjusted with KN2≈KN1 as the target to obtain the air-fuel ratio Lam2 and the ignition angle ADV2, thus forming the second MAP curve.

9. A motor vehicle, characterized in that, It has an on-board control unit, through which the steps of the gas composition adaptive control method as described in any one of claims 1-7 are executed.

10. An electronic device, characterized in that, It includes at least one processor and a memory connected to the processor, the memory being used to store a computer program; the processor is used to execute the computer program, enabling the electronic device to perform the steps in the gas composition adaptive control method as described in any one of claims 1-7.

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