Control method for slightly igniting any alternative fuel engine by diesel oil

Abstract

The invention discloses a control method for slightly igniting any alternative fuel engine by diesel oil. The control method mainly comprises the following steps: acquiring a real-time knock signal; according to the real-time knock signal, whether knock occurs currently or not is judged; if knocking occurs, the knocking grade is determined; generating an intervention level signal according to the knock level; obtaining an intervention measure of a corresponding level according to the intervention signal; and according to the intervention measures, the current replacement rate, the current rail pressure and the current advance angle are adjusted according to the preset slope, or according to the intervention measures, the dual-fuel mode is quitted to enter the pure diesel mode, or according to the intervention measures, fault idling operation is conducted. Therefore, aiming at the engine adopting any alternative fuel premixed gas and diesel oil ignition combustion technology, active staged treatment of detonation is realized in the full-working-condition operation process, the detonation is effectively inhibited, the reliability of the full life cycle of the engine is guaranteed, the power performance under the emergency condition is kept to the maximum extent, and the reliability of the engine is improved. And the emergency risk avoiding capability of the vehicle is ensured.

Description

Technical Field

[0001] This invention relates to the field of engine technology, and in particular to a control method for a diesel micro-ignition engine capable of using any alternative fuel. Background Technology

[0002] Methanol and natural gas, as alternative low-carbon fuels to diesel, can improve the combustion and emission performance of compression-ignition engines and have significant carbon reduction potential in the medium to long term. Therefore, they are widely used in compression-ignition engines. However, methanol, due to its significantly higher latent heat of vaporization than diesel, and natural gas, due to its relatively lower energy density, flame propagation speed, and high auto-ignition temperature, are not suitable for use as a single fuel in diesel engines. Furthermore, pure methanol or pure natural gas can cause misfires and difficulties in cold starting during actual operation of compression-ignition engines. Therefore, it is necessary to use a small amount of diesel as a highly reactive fuel to ignite relatively less reactive alternative fuels in compression-ignition engines to solve these problems. Specifically, this can be divided into diesel-alternative fuel mixed direct injection compression ignition combustion, alternative fuel premixed gas diesel ignition combustion, and diesel ignition high-pressure direct injection alternative fuel combustion.

[0003] However, when the operating conditions and load of an engine using premixed diesel ignition combustion technology change, the turbocharger's lag and the fluctuation of the intake air volume can cause uneven mixing of the premixed alternative fuel combustible mixture with the working fluid in the cylinder. This can result in an excessively rich mixture in some areas, leading to detonation and knocking. The in-cylinder explosion pressure can exceed the design limit and the mechanical strength of the cylinder block, thus damaging the engine's reliability.

[0004] Especially when ship engines are subjected to high load and rapid acceleration, they face problems such as occasional difficulty in cyclic ignition or even misfire, resulting in extremely unstable combustion in the next cycle and the occurrence of severe knocking. Summary of the Invention

[0005] To address the aforementioned shortcomings, the technical problem to be solved by this invention is to provide a control method for a diesel micro-ignition engine capable of using any alternative fuel. During full-condition operation, when engine knock occurs, a multi-stage degradation process is implemented. This reduces the damage of knock to the engine's reliability throughout its entire life cycle while ensuring that the engine has sufficient power performance in emergency situations, thus ensuring that emergency avoidance capabilities are not lost.

[0006] To solve the above-mentioned technical problems, the technical solution of the present invention is as follows:

[0007] A control method for a diesel micro-ignition engine capable of igniting any alternative fuel includes the following steps:

[0008] S10, Obtain real-time knock signal;

[0009] S20. Determine whether a detonation has occurred based on the real-time detonation signal;

[0010] S30. If a detonation occurs, determine the detonation level;

[0011] If no knocking occurs, proceed to S10;

[0012] S40. Generate an intervention signal of the corresponding level based on the knock level;

[0013] S50. Based on the intervention signal, obtain the corresponding level of intervention measures;

[0014] S60. Based on the intervention measures, adjust the current substitution rate, current rail pressure, and current advance angle according to the preset slope; or based on the intervention measures, exit the dual-fuel mode and enter the pure diesel mode; or based on the intervention measures, operate at fault idling speed.

[0015] The preferred embodiment is that the detonation levels include Level 1, Level 2, Level 3, Level 4, and Level 5 detonation; and the intervention measures include Level 1, Level 2, Level 3, Level 4, and Level 5 intervention measures.

[0016] The step of determining the detonation level if a detonation occurs, as described in S30, includes:

[0017] S300. If a detonation occurs, determine whether the detonation intensity is a mild detonation, whether Level 1 intervention measures have been implemented, whether Level 2 intervention measures have been implemented, whether Level 3 intervention measures have been implemented, and whether Level 4 intervention measures have been implemented.

[0018] S310. If the detonation intensity is mild, then the detonation level is determined to be Level 1 detonation.

[0019] If Level 1 intervention measures have been implemented, the detonation level is determined to be Level 2 detonation.

[0020] If level 2 intervention measures have been implemented, the detonation level is determined to be level 3 detonation;

[0021] If Level 3 intervention measures have been implemented, the detonation level is determined to be Level 4 detonation.

[0022] If Level 4 intervention measures have been implemented, the detonation level is determined to be Level 5 detonation.

[0023] The preferred method is that, in step S30, if no detonation occurs, step S10 is executed, including:

[0024] S320. If no detonation occurs, determine whether Level 1 intervention measures have been implemented, whether Level 2 intervention measures have been implemented, whether Level 3 intervention measures have been implemented, and whether Level 4 intervention measures have been implemented.

[0025] S330. If no knocking occurs and no Level 1 intervention measures are implemented, set the current replacement rate to the preset replacement rate target value, set the current rail pressure to the preset rail pressure target value, set the current advance angle to the preset advance angle target value, and execute S10.

[0026] If no knocking occurs and Level 1 intervention measures have been implemented, then restore the current replacement rate to the preset replacement rate target value according to the slope K11, set the current rail pressure to the preset rail pressure target value, set the current advance angle to the preset advance angle target value, and execute S10;

[0027] If no knocking occurs and secondary intervention measures have been implemented, then restore the current replacement rate to the preset replacement rate target value according to the slope K12, restore the current rail pressure to the preset rail pressure target value according to the slope KR12, restore the current advance angle to the preset advance angle target value according to the slope KP12, and execute S10;

[0028] If no knocking occurs and level 3 intervention measures have been implemented, then restore the current replacement rate to the preset replacement rate target value according to slope K13, restore the current rail pressure to the preset rail pressure target value according to slope KR13, restore the current advance angle to the preset advance angle target value according to slope KP13, and execute S10;

[0029] If no knocking occurs and level 4 intervention measures have been implemented, then enter dual-fuel mode, restore the current replacement rate to the preset replacement rate target value according to slope K14, restore the current rail pressure to the preset rail pressure target value according to slope KR14, restore the current advance angle to the preset advance angle target value according to slope KP14, and execute S10.

[0030] The preferred method is that when the detonation level is level one detonation,

[0031] S40 includes:

[0032] S410. Generate a corresponding first-level intervention signal based on the first-level detonation.

[0033] The S50 includes:

[0034] S510. Based on the primary intervention signal, obtain the corresponding primary intervention measures;

[0035] The S60 includes:

[0036] S610. According to the first-level intervention measures, the current replacement rate is reduced by a% according to the slope K21, the current rail pressure is the preset rail pressure target value, and the current advance angle is the preset advance angle target value.

[0037] The preferred method is when the detonation level is level two detonation.

[0038] S40 includes:

[0039] S420: Generate a corresponding secondary intervention signal based on the secondary detonation.

[0040] The S50 includes:

[0041] S520. Based on the secondary intervention signal, obtain the corresponding secondary intervention measures;

[0042] The S60 includes:

[0043] S620. According to the secondary intervention measures, adjust the current substitution rate to the preset secondary intervention value b according to the slope K22, adjust the current rail pressure to the preset secondary intervention rail pressure value according to the slope KR22, and adjust the current advance angle to the preset secondary intervention advance angle according to the slope KP22.

[0044] The preferred method is when the detonation level is level three,

[0045] S40 includes:

[0046] S430: Based on the three-level detonation, generate the corresponding three-level intervention signal;

[0047] The S50 includes:

[0048] S530. Based on the three-level intervention signals, obtain the corresponding three-level intervention measures;

[0049] The S60 includes:

[0050] S630. According to the three-level intervention measures, control the engine speed to Va and the torque to Na, adjust the current substitution rate to the preset second-level intervention value c% according to the slope K23, adjust the current rail pressure to the preset second-level intervention rail pressure value according to the slope KR23, and adjust the current advance angle to the preset second-level intervention advance angle according to the slope KP23.

[0051] The preferred method is when the detonation level is level four,

[0052] S40 includes:

[0053] S440: Generate a corresponding level 4 intervention signal based on level 4 detonation.

[0054] The S50 includes:

[0055] S540. Based on the Level 4 intervention signal, obtain the corresponding Level 4 intervention measures;

[0056] The S60 includes:

[0057] S640, according to the level four intervention measures, exits dual-fuel mode and enters pure diesel mode.

[0058] The preferred method is when the detonation level is level 5,

[0059] S40 includes:

[0060] S450: Based on the five-level detonation, generate the corresponding five-level intervention signal;

[0061] The S50 includes:

[0062] S550. Based on the five-level intervention signals, obtain the corresponding five-level intervention measures;

[0063] The S60 includes:

[0064] S650, according to the five-level intervention measures, the fault is idling.

[0065] The preferred method is that b% is the minimum replacement rate value that can maintain stable engine operation under the current engine operating conditions, and the minimum replacement rate value is determined by the maximum allowable energizing time of the injectors under the current engine configuration.

[0066] The preferred arrangement is as follows: slope K11 = slope K12 = slope K13 = slope K14; slope KR12 = slope KR13 = slope KR14; slope KP12 = slope KP13 = slope KP14.

[0067] After adopting the above technical solution, the beneficial effects of the present invention are:

[0068] The control method for a diesel micro-ignition engine using any alternative fuel in this invention mainly involves acquiring real-time knock signals; determining whether knock has occurred based on the real-time knock signals; determining the knock level if knock has occurred; generating corresponding intervention signals based on the knock level; obtaining corresponding intervention measures based on the intervention signals; and adjusting the current substitution rate, current rail pressure, and current advance angle according to a preset slope, or exiting dual-fuel mode and entering pure diesel mode, or idling at fault speed according to the intervention measures. Therefore, this invention, for engines using diesel micro-ignition combustion technology with any alternative fuel premixed gas, employs multi-stage degradation processing when engine knock occurs during full-condition operation. This reduces the damage to engine reliability throughout its entire lifecycle caused by knock while ensuring sufficient power performance in emergency situations, ensuring that emergency avoidance capabilities are not lost. Attached Figure Description

[0069] Figure 1 This is a flowchart illustrating the control method for a diesel micro-ignition engine capable of using any alternative fuel.

[0070] Figure 2 This is a logic diagram of the control method for a diesel micro-ignition arbitrary alternative fuel engine in this invention. Detailed Implementation

[0071] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0072] It should be noted that in the description of this invention, the terms "upper", "lower", "left", "right", "inner", "outer", etc., which indicate directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings. This is only for the convenience of description and is not intended to indicate or imply that the device or element must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of this invention.

[0073] Furthermore, it should be noted that, in the description of this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0074] The substitution rate MAP involved in this invention refers to a table that controls the proportion of methanol in dual-fuel mode. The X-axis is the engine speed, the Y-axis is the current intake air volume of the engine, and the Z-axis is the proportion of methanol per cycle when the engine is running in dual-fuel mode. Its function is to achieve different substitution rates at different speeds and loads.

[0075] The advance angle MAP involved in this invention refers to a table for controlling the timing of diesel injection in dual-fuel mode. The X-axis is the engine speed, the Y-axis is the current intake air volume of the engine, and the Z-axis is the current injection time of the engine when running in dual-fuel mode. Its function is to realize different diesel injection times under various speeds and loads.

[0076] The rail pressure MAP involved in this invention refers to a table for controlling the fuel rail pressure in dual-fuel mode. The X-axis is the engine speed, the Y-axis is the current circulating fuel quantity of the engine, and the Z-axis is the fuel rail pressure at the current moment when the engine is running in dual-fuel mode. Its function is to achieve different fuel rail pressures under different speeds and loads.

[0077] like Figure 1 As shown, a control method for a diesel micro-ignition engine capable of igniting any alternative fuel includes the following steps:

[0078] Step S10: Obtain real-time detonation signal;

[0079] Step S20: Determine whether a detonation has occurred based on the real-time detonation signal;

[0080] Step S30: If a detonation occurs, determine the detonation level;

[0081] If no detonation occurs, proceed to step S10;

[0082] Step S40: Generate an intervention signal of the corresponding level based on the detonation level;

[0083] Step S50: Based on the intervention signal, obtain the corresponding level of intervention measures;

[0084] Step S60: According to the intervention measures, adjust the current substitution rate, current rail pressure and current advance angle according to the preset slope, or according to the intervention measures, exit the dual-fuel mode and enter the pure diesel mode, or according to the intervention measures, run at fault idling speed.

[0085] The control method of the present invention is designed for engines using premixed gas-diesel ignition combustion technology with any alternative fuel. During full-condition operation, when engine knock occurs, a multi-stage degradation process is adopted. This reduces the damage of knock to the reliability of the engine throughout its entire life cycle, while ensuring that the engine has sufficient power performance in emergency situations and ensuring that emergency avoidance capabilities are not lost.

[0086] It should be noted that the present invention is applied to the control device of a diesel micro-ignition engine for any alternative fuel. The device includes an engine speed sensor, an engine control unit (ECU), an intercooler temperature sensor, an intercooler pressure sensor, a target substitution rate MAP, a target rail pressure MAP, a target advance angle MAP, a secondary intervention substitution rate MAP, a secondary intervention rail pressure MAP, a secondary intervention advance angle MAP, a fuel injection pump, and an injection valve.

[0087] During engine operation, the ECU uses the voltage signal from the knock sensor to determine the current knock intensity in real time, classifies the knock level based on the intensity, and then selects the corresponding intervention signal and executes the appropriate intervention measures. Based on the intervention measures, the ECU selects the corresponding target values ​​for substitution rate, fuel rail pressure, and fuel injection advance angle, and performs transitional execution according to the slope of the intervention measures to prevent engine instability caused by sudden changes in substitution rate, fuel rail pressure, and fuel injection advance angle during the implementation of downgraded intervention measures or the recovery process. The ECU then transmits the substitution rate, fuel injection advance angle, and fuel rail pressure to the actuators—injectors, injection valves, and fuel metering unit—to control the fuel gas quantity, fuel injection quantity, injection advance angle, and fuel rail pressure values ​​under different substitution rates, ensuring stable engine operation.

[0088] like Figure 2 As shown, the control method of the present invention includes detonation levels of Level 1, Level 2, Level 3, Level 4, and Level 5; and intervention measures including Level 1, Level 2, Level 3, Level 4, and Level 5 intervention measures. Specifically, when Level 1 detonation occurs, Level 1 intervention measures are adopted; when Level 2 detonation occurs, Level 2 intervention measures are adopted; when Level 3 detonation occurs, Level 3 intervention measures are adopted; when Level 4 detonation occurs, Level 4 intervention measures are adopted; when Level 5 detonation occurs, Level 5 intervention measures are adopted; and when no detonation occurs, normal operation is maintained.

[0089] The control method of the present invention, in step S30, the step of determining the detonation level if detonation occurs, specifically includes:

[0090] Step S300: If a detonation occurs, determine whether the detonation intensity is a mild detonation, determine whether a Level 1 intervention measure has been implemented, determine whether a Level 2 intervention measure has been implemented, determine whether a Level 3 intervention measure has been implemented, and determine whether a Level 4 intervention measure has been implemented.

[0091] Step S310: If the detonation intensity is mild, then the detonation level is determined to be Level 1 detonation;

[0092] If Level 1 intervention measures have been implemented, the detonation level is determined to be Level 2 detonation.

[0093] If level 2 intervention measures have been implemented, the detonation level is determined to be level 3 detonation;

[0094] If Level 3 intervention measures have been implemented, the detonation level is determined to be Level 4 detonation.

[0095] If Level 4 intervention measures have been implemented, the detonation level is determined to be Level 5 detonation.

[0096] The control method of the present invention, wherein if no detonation occurs in step S30, step S10 is executed, specifically includes:

[0097] Step S320: If no detonation occurs, determine whether Level 1 intervention measures have been implemented, whether Level 2 intervention measures have been implemented, whether Level 3 intervention measures have been implemented, and whether Level 4 intervention measures have been implemented.

[0098] Step S330: If no knocking occurs and no first-level intervention measures are implemented, set the current substitution rate to the preset substitution rate target value, set the current rail pressure to the preset rail pressure target value, set the current advance angle to the preset advance angle target value, and execute step S10.

[0099] It should be noted that during engine operation, the ECU detects voltage signals through the knock sensor, monitors and determines the current knock level of the engine in real time. If it determines that no knock has occurred, it indicates that the engine is operating normally. In addition, the target replacement rate values ​​mentioned below are all lookup table values ​​in the Target Replacement Rate MAP, the target rail pressure values ​​mentioned below are all lookup table values ​​in the Target Rail Pressure MAP, and the target advance angle values ​​mentioned below are all lookup table values ​​in the Target Advance Angle MAP.

[0100] If no knocking occurs and Level 1 intervention measures have been implemented, the current replacement rate is restored to the preset replacement rate target value according to the slope K11, the current rail pressure is set to the preset rail pressure target value, and the current advance angle is set to the preset advance angle target value. Then, step S10 is executed; where the slope K11 can be calibrated to 0.5%.

[0101] It should be noted that after the ECU performs the first-level intervention, the ECU continuously monitors the knock signal. If the knock signal indicates that the knock has disappeared, it means that the engine does not need to undergo downgrade intervention.

[0102] Step S330: If no knocking has occurred and secondary intervention measures have been implemented, then restore the current replacement rate to the preset replacement rate target value according to the slope K12, restore the current rail pressure to the preset rail pressure target value according to the slope KR12, restore the current advance angle to the preset advance angle target value according to the slope KP12, and execute step S10; wherein the slope K12 can be calibrated to 0.5%, KR12 can be calibrated to 1MPa, and KP12 can be calibrated to 0.5°CA.

[0103] It should be noted that after the ECU performs the secondary intervention measures, the ECU continues to monitor the knock signal. If the knock signal indicates that the knock has disappeared, it means that the engine does not need to undergo downgrade intervention measures.

[0104] Step S330: If no knocking has occurred and level 3 intervention measures have been implemented, then restore the current replacement rate to the preset replacement rate target value according to the slope K13, restore the current rail pressure to the preset rail pressure target value according to the slope KR13, restore the current advance angle to the preset advance angle target value according to the slope KP13, and execute step S10; wherein the slope K13 can be calibrated to 0.5%, KR13 can be calibrated to 1MPa, and KP13 can be calibrated to 0.5°CA.

[0105] It should be noted that after the ECU performs the three-level intervention measures, the ECU continuously monitors the knock signal. If the knock signal indicates that the knock has disappeared, it means that the engine does not need to undergo downgrade intervention measures.

[0106] Step S330: If no knocking occurs and level four intervention measures have been implemented, enter dual-fuel mode, restore the current replacement rate to the preset replacement rate target value according to slope K14, restore the current rail pressure to the preset rail pressure target value according to slope KR14, restore the current advance angle to the preset advance angle target value according to slope KP14, and execute step S10; wherein the slope K14 can be calibrated to 0.5%, KR14 can be calibrated to 1MPa, and KP14 can be calibrated to 0.5°CA.

[0107] It should be noted that after the ECU performs the fourth-level intervention measures, the ECU continuously monitors the knock signal. If the knock signal indicates that the knock has disappeared, it means that the engine does not need to undergo downgrade intervention measures.

[0108] In a preferred configuration, the slopes K11 = K12 = K13 = K14; KR12 = KR13 = KR14; and KP12 = KP13 = KP14. Of course, the slopes can be different.

[0109] This invention determines the knock level through the above method and implements a step-by-step downgrade intervention based on the knock intensity. This avoids the need for multi-level downgrade treatment when engine knock occurs. While reducing the damage of knock to the reliability of the engine throughout its entire life cycle, it also ensures that the engine has sufficient power performance in emergency situations and ensures that emergency avoidance capabilities are not lost.

[0110] like Figure 2 As shown, when the detonation level is Level 1, the specific details are as follows:

[0111] Step S40 includes:

[0112] Step S410: Generate the corresponding first-level intervention signal based on the first-level detonation.

[0113] Step S50 includes:

[0114] Step S510: Based on the primary intervention signal, obtain the corresponding primary intervention measures;

[0115] Step S60 includes:

[0116] Step S610: According to the first-level intervention measures, the current replacement rate is reduced by a% according to the slope K21, the current rail pressure is the preset rail pressure target value, and the current advance angle is the preset advance angle target value.

[0117] It should be noted that if the judgment result is that the engine has experienced mild knocking, then the first-level intervention measures will be implemented. The replacement rate will be rapidly reduced by a% (or 5%) according to the slope K11 (which can be calibrated to 1%) based on the current table lookup value, while the advance angle and rail pressure will remain unchanged from the current table lookup value.

[0118] like Figure 2 As shown, when the detonation level is level two, the specific details are as follows:

[0119] Step S40 includes:

[0120] Step S420: Generate the corresponding secondary intervention signal based on the secondary detonation.

[0121] Step S50 includes:

[0122] Step S520: Based on the secondary intervention signal, obtain the corresponding secondary intervention measures;

[0123] Step S60 includes:

[0124] Step S620: According to the secondary intervention measures, adjust the current substitution rate to the preset secondary intervention value b% according to the slope K22, adjust the current rail pressure to the preset secondary intervention rail pressure value according to the slope KR22, and adjust the current advance angle to the preset secondary intervention advance angle according to the slope KP22. Wherein, the preset secondary intervention value b% is a lookup value obtained from the secondary intervention MAP, the preset secondary intervention rail pressure value is a lookup value obtained from the secondary intervention MAP, the preset secondary intervention advance angle is a lookup value obtained from the secondary intervention MAP, b% can be calibrated, such as 70%, the slope K22 can be calibrated to 1%, the slope KR22 can be calibrated to 5MPa, and the slope KP22 can be calibrated to 1°CA.

[0125] It should be noted that after the ECU executes the first-level intervention measures, the ECU continuously monitors the knock signal. If the knock signal does not disappear, the ECU executes the second-level intervention measures, continuing to rapidly reduce the replacement rate according to the slope K22 to the second-level intervention replacement rate b%, where b% is the minimum replacement rate value that can maintain stable engine operation under the current engine operating conditions. This value is determined by the maximum allowable energizing time of the injectors under the current engine configuration. The rail pressure rapidly transitions from the current operating value to the second-level intervention lookup value according to the slope KR22. The advance angle rapidly transitions from the current operating value to the second-level intervention lookup value according to the slope KR22.

[0126] like Figure 2 As shown, when the detonation level is level three, the specific details are as follows:

[0127] Step S40 includes:

[0128] Step S430: Generate the corresponding level 3 intervention signal based on the level 3 detonation.

[0129] Step S50 includes:

[0130] Step S530: Based on the three-level intervention signals, obtain the corresponding three-level intervention measures;

[0131] Step S60 includes:

[0132] Step S630: According to the three-level intervention measures, control the engine speed to limit Va and the torque to limit Na. Adjust the current substitution rate to the preset secondary intervention value c% according to the slope K23. Adjust the current rail pressure to the preset secondary intervention rail pressure value according to the slope KR23. Adjust the current advance angle to the preset secondary intervention advance angle according to the slope KP23. Va can be calibrated to 700 r / min, K23 can be calibrated to 1%, KR23 can be calibrated to 5 MPa, KP23 can be calibrated to 1°CA, and c% can be calibrated to 60%. The preset secondary intervention rail pressure value and the preset secondary intervention advance angle can be found in the secondary intervention MAP under the speed limit.

[0133] It should be noted that after the ECU executes the secondary intervention measures, if the ECU continues to monitor the knock signal and the knock signal does not disappear, the ECU will execute the tertiary intervention measures, limiting the engine speed to Va and the torque to Na, where Na is determined by the external characteristics of Va and the amount of fuel. The substitution rate will rapidly decrease from the current value to the secondary intervention substitution rate lookup value c% at the speed limit, where c is the minimum substitution rate value that can maintain stable engine operation at the speed limit, which is determined by the maximum allowable injection time of the injectors under the current engine configuration; the rail pressure will rapidly transition from the current value to the secondary intervention lookup value at the speed limit according to the slope KR23; and the advance angle will rapidly transition from the current value to the secondary intervention lookup value at the speed limit according to the slope KP23.

[0134] like Figure 2 As shown, when the detonation level is level four, the specific details are as follows:

[0135] Step S40 includes:

[0136] Step S440: Generate the corresponding level 4 intervention signal based on the level 4 detonation.

[0137] Step S50 includes:

[0138] Step S540: Based on the level four intervention signals, obtain the corresponding level four intervention measures;

[0139] Step S60 includes:

[0140] Step S640: According to the fourth-level intervention measures, exit the dual-fuel mode and enter the pure diesel mode.

[0141] It should be noted that after the ECU performs the third-level intervention measures, if the ECU continues to monitor the knock signal and the knock signal does not disappear, the ECU will perform the fourth-level intervention measures, and the engine will exit the dual-fuel mode and enter the pure diesel mode. At this time, the pure diesel capacity of the engine is determined by the maximum allowable energizing time of the injectors at different speeds under the current engine configuration and the allowable rail pressure limit.

[0142] like Figure 2 As shown, when the detonation level is level 5, the specific details are as follows:

[0143] Step S40 includes:

[0144] Step S450: Generate the corresponding level 5 intervention signal based on the level 5 detonation.

[0145] Step S50 includes:

[0146] Step S550: Based on the five-level intervention signals, obtain the corresponding five-level intervention measures;

[0147] Step S60 includes:

[0148] Step S650: According to the five-level intervention measures, the fault idles.

[0149] It should be noted that after the ECU performs the fourth-level intervention measures, if the ECU continues to monitor the knock signal and the knock signal does not disappear, the ECU will perform the fifth-level intervention downgrade measures, and the engine will enter fault idling operation.

[0150] In summary, this invention addresses the problem that in marine engines using diesel micro-ignition alternative fuels, simply retarding the ignition advance angle during knocking can easily cause misfires and knocking, even leading to engine power loss. By using the engine ECU to monitor the knock sensor signal in real time, identifying and determining the knock level, and taking corresponding intervention measures such as reducing the substitution rate and retarding the ignition advance angle under different knocking conditions, this invention ensures that the diesel micro-ignition alternative fuel engine equipment, even in the event of knocking, will not suffer serious damage to the engine under all operating conditions, while simultaneously ensuring sufficient engine power performance and strong emergency avoidance capabilities.

[0151] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications or improvements to the control method of a diesel micro-ignition engine for any alternative fuel made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A control method for a diesel micro-ignition engine capable of igniting any alternative fuel, characterized in that, Includes the following steps: S10, Obtain real-time knock signal; S20. Determine whether a detonation has occurred based on the real-time detonation signal; S30. If a detonation occurs, determine the detonation level; If no knocking occurs, proceed to S10; S40. Generate an intervention signal of the corresponding level based on the knock level; S50. Based on the intervention signal, obtain the corresponding level of intervention measures; S60. Based on the intervention measures, adjust the current substitution rate, current rail pressure, and current advance angle according to the preset slope; or based on the intervention measures, exit the dual-fuel mode and enter the pure diesel mode; or based on the intervention measures, operate at fault idling speed.

2. The control method for a diesel micro-ignition engine with any alternative fuel according to claim 1, characterized in that, The detonation levels include Level 1, Level 2, Level 3, Level 4, and Level 5 detonation; the intervention measures include Level 1, Level 2, Level 3, Level 4, and Level 5 intervention measures. The step of determining the detonation level if a detonation occurs, as described in S30, includes: S300. If a detonation occurs, determine whether the detonation intensity is a mild detonation, whether a Level 1 intervention measure has been implemented, whether a Level 2 intervention measure has been implemented, whether a Level 3 intervention measure has been implemented, and whether a Level 4 intervention measure has been implemented. S310. If the detonation intensity is mild, then the detonation level is determined to be Level 1 detonation. If Level 1 intervention measures have been implemented, the detonation level is determined to be Level 2 detonation. If level 2 intervention measures have been implemented, the detonation level is determined to be level 3 detonation; If Level 3 intervention measures have been implemented, the detonation level is determined to be Level 4 detonation. If Level 4 intervention measures have been implemented, the detonation level is determined to be Level 5 detonation.

3. The control method for a diesel micro-ignition engine with any alternative fuel according to claim 2, characterized in that, If no detonation occurs as described in S30, step S10 is executed, including: S320. If no detonation occurs, determine whether Level 1 intervention measures have been implemented, whether Level 2 intervention measures have been implemented, whether Level 3 intervention measures have been implemented, and whether Level 4 intervention measures have been implemented. S330. If no knocking occurs and no Level 1 intervention measures are implemented, set the current replacement rate to the preset replacement rate target value, set the current rail pressure to the preset rail pressure target value, set the current advance angle to the preset advance angle target value, and execute S10. If no knocking occurs and Level 1 intervention measures have been implemented, then restore the current replacement rate to the preset replacement rate target value according to the slope K11, set the current rail pressure to the preset rail pressure target value, set the current advance angle to the preset advance angle target value, and execute S10; If no knocking occurs and secondary intervention measures have been implemented, then restore the current replacement rate to the preset replacement rate target value according to the slope K12, restore the current rail pressure to the preset rail pressure target value according to the slope KR12, restore the current advance angle to the preset advance angle target value according to the slope KP12, and execute S10; If no knocking occurs and level 3 intervention measures have been implemented, then restore the current replacement rate to the preset replacement rate target value according to slope K13, restore the current rail pressure to the preset rail pressure target value according to slope KR13, restore the current advance angle to the preset advance angle target value according to slope KP13, and execute S10; If no knocking occurs and level 4 intervention measures have been implemented, then enter dual-fuel mode, restore the current replacement rate to the preset replacement rate target value according to slope K14, restore the current rail pressure to the preset rail pressure target value according to slope KR14, restore the current advance angle to the preset advance angle target value according to slope KP14, and execute S10.

4. The control method for a diesel micro-ignition engine with any alternative fuel according to claim 3, characterized in that, When the detonation level is level one detonation S40 includes: S410. Generate a corresponding first-level intervention signal based on the first-level detonation. The S50 includes: S510. Based on the primary intervention signal, obtain the corresponding primary intervention measures; The S60 includes: S610. According to the first-level intervention measures, the current replacement rate is reduced by a% according to the slope K21, the current rail pressure is the preset rail pressure target value, and the current advance angle is the preset advance angle target value.

5. The control method for a diesel micro-ignition engine with any alternative fuel according to claim 3, characterized in that, When the detonation level is level two detonation S40 includes: S420: Generate a corresponding secondary intervention signal based on the secondary detonation. The S50 includes: S520. Based on the secondary intervention signal, obtain the corresponding secondary intervention measures; The S60 includes: S620. According to the secondary intervention measures, adjust the current substitution rate to the preset secondary intervention value b according to the slope K22, adjust the current rail pressure to the preset secondary intervention rail pressure value according to the slope KR22, and adjust the current advance angle to the preset secondary intervention advance angle according to the slope KP22.

6. The control method for a diesel micro-ignition engine with any alternative fuel according to claim 3, characterized in that, When the detonation level is level three detonation S40 includes: S430: Based on the three-level detonation, generate the corresponding three-level intervention signal; The S50 includes: S530. Based on the three-level intervention signals, obtain the corresponding three-level intervention measures; The S60 includes: S630. According to the three-level intervention measures, control the engine speed to Va and the torque to Na, adjust the current substitution rate to the preset second-level intervention value c% according to the slope K23, adjust the current rail pressure to the preset second-level intervention rail pressure value according to the slope KR23, and adjust the current advance angle to the preset second-level intervention advance angle according to the slope KP23.

7. The control method for a diesel micro-ignition engine with any alternative fuel according to claim 3, characterized in that, When the detonation level is level four detonation S40 includes: S440: Generate a corresponding level 4 intervention signal based on level 4 detonation. The S50 includes: S540. Based on the Level 4 intervention signal, obtain the corresponding Level 4 intervention measures; The S60 includes: S640, according to the level four intervention measures, exits dual-fuel mode and enters pure diesel mode.

8. The control method for a diesel micro-ignition engine with any alternative fuel according to claim 3, characterized in that, When the detonation level is level 5, S40 includes: S450: Based on the five-level detonation, generate the corresponding five-level intervention signal; The S50 includes: S550. Based on the five-level intervention signals, obtain the corresponding five-level intervention measures; The S60 includes: S650, according to the five-level intervention measures, the fault is idling.

9. The control method for a diesel micro-ignition engine with any alternative fuel according to claim 5, characterized in that, b% is the minimum replacement rate value that can maintain stable engine operation under the current engine operating conditions. The minimum replacement rate value is determined by the maximum allowable energizing time of the injectors under the current engine configuration.

10. The control method for a diesel micro-ignition engine for any alternative fuel according to claim 3, characterized in that, Slope K11 = Slope K12 = Slope K13 = Slope K14; Slope KR12 = Slope KR13 = Slope KR14; Slope KP12 = Slope KP13 = Slope KP14.

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