Engine knock control method and system based on boundary conditions

Abstract

The application provides an engine knock control method and system based on boundary conditions, and relates to the technical field of engine control. The method comprises the following steps: selecting an engine operating parameter as a first boundary condition, a temperature parameter as a second boundary condition, and a knock coefficient as a third boundary condition; setting a logical true-false judgment relationship of the first boundary condition, the second boundary condition and the third boundary condition; when the first boundary condition, the second boundary condition and the third boundary condition are all true, calculating the sum of a water temperature correction ignition angle, an intake pipe temperature correction ignition angle, an intake temperature correction ignition angle and an intake pipe pressure correction ignition angle as a correction value of an ignition angle; and calculating the difference between a basic ignition angle and the correction value of the ignition angle as a corrected engine ignition angle. The application improves the adaptability of the engine under different boundary conditions, and reduces the false alarm rate of the knock fault.

Description

Technical Field

[0001] This invention belongs to the field of engine control technology, and particularly relates to an engine knock control method and system based on boundary conditions. Background Technology

[0002] Knocking, also known as engine knocking, is a condition in gasoline engines where combustion and pressure fluctuations occur within the cylinders due to factors such as an incorrect air-fuel ratio. To improve engine thermal efficiency and smooth operation, knocking in gasoline engines must be avoided.

[0003] Traditional engine knock control solutions typically involve installing a knock sensor inside the engine. During knock correction, the ignition angle is adjusted based on the knock coefficient calculated by the knock sensor to reduce the engine's knock tendency.

[0004] The inventors discovered that under current control strategies, the calculation of knock coefficients varies for different engines, which can easily lead to misdiagnosis or false alarms. Furthermore, natural gas engines exhibit different knock tendencies under different boundary conditions; severe knocking can cause a series of damages, such as piston crown melting and cylinder scoring, ultimately resulting in engine failure. Summary of the Invention

[0005] To overcome the shortcomings of the prior art, this invention provides an engine knock control method and system based on boundary conditions. By calculating the engine operating state under different boundary conditions and the current knock coefficient, the basic ignition angle is corrected according to the boundary conditions, thereby improving the engine's adaptability under different boundary conditions and reducing the false alarm rate of knock faults.

[0006] To achieve the above objectives, one or more embodiments of the present invention provide the following technical solutions:

[0007] The first aspect of this invention provides an engine knock control method based on boundary conditions.

[0008] The engine knock control method based on boundary conditions includes the following steps:

[0009] Engine operating parameters are selected as the first boundary condition, temperature parameters as the second boundary condition, and knock coefficient as the third boundary condition. Logical truth-false relationships are set for the first, second, and third boundary conditions.

[0010] When the first boundary condition, the second boundary condition, and the third boundary condition are all true, calculate the sum of the water temperature corrected ignition angle, the intake manifold temperature corrected ignition angle, the intake air temperature corrected ignition angle, and the intake manifold pressure corrected ignition angle, and use it as the ignition angle correction value.

[0011] The difference between the base ignition angle and the ignition angle correction value is calculated and used as the corrected engine ignition angle.

[0012] A second aspect of the present invention provides an engine knock control system based on boundary conditions.

[0013] The boundary condition-based engine knock control system includes:

[0014] The boundary condition determination module is configured to: select engine operating parameters as the first boundary condition, temperature parameters as the second boundary condition, and knock coefficient as the third boundary condition, and set the logical truth-false judgment relationship between the first boundary condition, the second boundary condition, and the third boundary condition;

[0015] The logic determination module is configured to: when the first boundary condition, the second boundary condition, and the third boundary condition are all true, calculate the sum of the water temperature corrected ignition angle, the intake manifold temperature corrected ignition angle, the intake air temperature corrected ignition angle, and the intake manifold pressure corrected ignition angle, and use it as the ignition angle correction value.

[0016] The correction module is configured to calculate the difference between the base ignition angle and the ignition angle correction value, and use this difference as the corrected engine ignition angle.

[0017] A third aspect of the present invention provides a computer-readable storage medium having a program stored thereon, which, when executed by a processor, implements the steps of the boundary condition-based engine knock control method as described in the first aspect of the present invention.

[0018] A fourth aspect of the present invention provides an electronic device including a memory, a processor, and a program stored in the memory and executable on the processor, wherein the processor executes the program to implement the steps of the boundary condition-based engine knock control method as described in the first aspect of the present invention.

[0019] The above one or more technical solutions have the following beneficial effects:

[0020] This invention provides an engine knock control method and system based on boundary conditions. It considers a variety of different boundary conditions, selecting engine running time, intake manifold pressure, and engine speed as the first boundary conditions, water temperature, intake manifold temperature, and intake air temperature as the second boundary conditions, and the knock coefficient as the third boundary condition. By considering different boundary conditions and the current knock coefficient, the engine operating state is calculated, and the basic ignition angle is corrected according to the boundary conditions. This improves the engine's adaptability under different boundary conditions and reduces the false alarm rate of knock faults.

[0021] This invention can monitor engine operation under different boundary conditions. When the first boundary condition, the second boundary condition, and the third boundary condition are all true, the ignition angle is corrected by ECT / MAT / RHT / MAP to avoid the risk of knock in advance and reduce the false alarm rate of knock fault.

[0022] Advantages of additional aspects of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0023] 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.

[0024] Figure 1 This is a flowchart of the method in the first embodiment. Detailed Implementation

[0025] 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.

[0026] 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 exemplary implementations of the present invention.

[0027] Where there is no conflict, the embodiments and features in the embodiments of the present invention can be combined with each other.

[0028] Terminology Explanation:

[0029] MAP: Manifold Air Pressure;

[0030] ECT: Water temperature;

[0031] MAT: Intake pipe temperature;

[0032] RHT: Intake air temperature.

[0033] Example 1

[0034] This embodiment discloses an engine knock control method based on boundary conditions.

[0035] like Figure 1 As shown, the engine knock control method based on boundary conditions includes the following steps:

[0036] Engine operating parameters are selected as the first boundary condition, temperature parameters as the second boundary condition, and knock coefficient as the third boundary condition. Logical truth-false relationships are set for the first, second, and third boundary conditions.

[0037] When the first boundary condition, the second boundary condition, and the third boundary condition are all true, calculate the sum of the water temperature corrected ignition angle, the intake manifold temperature corrected ignition angle, the intake air temperature corrected ignition angle, and the intake manifold pressure corrected ignition angle, and use it as the ignition angle correction value.

[0038] The difference between the base ignition angle and the ignition angle correction value is calculated and used as the corrected engine ignition angle.

[0039] The timing of ignition has a significant impact on engine performance. Ignition is the process by which the spark plug ignites the combustible mixture in the combustion chamber before the piston reaches top dead center on the compression stroke. The angle through which the crankshaft rotates from the moment of ignition until the piston reaches top dead center on the compression stroke is called the ignition angle.

[0040] The corrected engine ignition angle is used as the angle through which the crankshaft rotates during the time from ignition to the piston reaching top dead center of compression, and the engine is controlled accordingly.

[0041] In this embodiment, three boundary conditions are considered. Multiple parameters are selected from the first and second boundary conditions, so that the first boundary condition mainly reflects the engine operating status, the second boundary condition mainly reflects the temperature status, and the third boundary condition mainly reflects the knock coefficient.

[0042] By considering multiple boundary conditions and various factors affecting the occurrence of knock, and by performing logical truth and falsehood judgments on the first, second, and third boundary conditions, the knock tendency of the engine is comprehensively determined, and it is determined whether the current engine ignition angle needs to be corrected, thereby improving the accuracy of the engine ignition angle.

[0043] Furthermore, the calculation method for the knockout coefficient is as follows:

[0044] Obtain the voltage signal from the knock sensor;

[0045] Energy integration is performed on the detonation window and the reference window using Fourier transform, respectively;

[0046] The ratio of the energy integral value of the detonation window to the energy integral value of the reference window is the detonation coefficient.

[0047] Furthermore, the logical truth-value relationships for the first, second, and third boundary conditions are defined as follows:

[0048] When the engine running time, intake manifold pressure and engine speed in the first boundary condition all exceed the corresponding preset limits, the first boundary condition is determined to be true.

[0049] When at least one of the water temperature, air intake pipe temperature and air intake temperature in the second boundary condition exceeds the corresponding preset limit, the second boundary condition is determined to be true.

[0050] When the knock coefficient exceeds the corresponding preset limit, the third boundary condition is determined to be true.

[0051] When at least one of the first boundary condition, the second boundary condition, and the third boundary condition is not true, the engine ignition angle is obtained based on the basic ignition angle table.

[0052] Going further:

[0053] The basic ignition angle table is derived from engine speed and intake manifold pressure.

[0054] The water temperature corrected ignition angle is obtained from the water temperature corrected ignition angle table;

[0055] The intake manifold temperature-corrected ignition angle is obtained from the intake manifold temperature-corrected ignition angle table;

[0056] The intake air temperature corrected ignition angle is obtained from the intake air temperature corrected ignition angle table;

[0057] The intake manifold pressure-corrected ignition angle is obtained from the intake manifold pressure-corrected ignition angle table.

[0058] In practical implementation, the following settings are pre-configured:

[0059] Engine running time limit 1, intake manifold pressure (MAP) limit 2, engine speed limit 3, coolant temperature (ECT) limit 4, intake manifold temperature (MAT) limit 5, intake air temperature (RHT) limit 6, knock factor limit 7.

[0060] Judgment condition 1: When the engine running time exceeds limit 1, MAP exceeds limit 2, and engine speed exceeds limit 3, the first boundary condition is determined to be true and the control system proceeds to the next judgment.

[0061] Judgment condition 2: When any one of the following three conditions is met, ECT exceeds limit 4, MAT exceeds limit 5, and RHT exceeds limit 6, the second boundary condition is determined to be true.

[0062] Judgment condition 3: Using the voltage signal from the knock sensor, the energy of the knock window and the reference window are integrated by Fourier transform respectively. The ratio of the knock window to the reference window is the knock coefficient (knock rat io value). When the knock coefficient exceeds the limit of 7, the third boundary condition is determined to be true.

[0063] The ignition angle calculation path is divided into two routes:

[0064] First path: When any one of the judgment conditions one, two and three is not true, the ignition angle comes from the basic ignition angle table based on the engine speed and MAP.

[0065] Second path: When conditions one, two and three are all true, the ignition angle path performs the basic ignition angle minus the ignition angle correction, and the ignition angle correction is the sum of the correction values ​​based on ECT / MAT / RHT / MAP.

[0066] Example 2

[0067] This embodiment discloses an engine knock control system based on boundary conditions.

[0068] The boundary condition-based engine knock control system includes:

[0069] The boundary condition determination module is configured to: select engine operating parameters as the first boundary condition, temperature parameters as the second boundary condition, and knock coefficient as the third boundary condition, and set the logical truth-false judgment relationship between the first boundary condition, the second boundary condition, and the third boundary condition;

[0070] The logic determination module is configured to: when the first boundary condition, the second boundary condition, and the third boundary condition are all true, calculate the sum of the water temperature corrected ignition angle, the intake manifold temperature corrected ignition angle, the intake air temperature corrected ignition angle, and the intake manifold pressure corrected ignition angle, and use it as the ignition angle correction value.

[0071] The correction module is configured to calculate the difference between the base ignition angle and the ignition angle correction value, and use this difference as the corrected engine ignition angle.

[0072] Example 3

[0073] The purpose of this embodiment is to provide a computer-readable storage medium.

[0074] A computer-readable storage medium having a computer program stored thereon that, when executed by a processor, implements the steps of the boundary condition-based engine knock control method as described in Embodiment 1 of this disclosure.

[0075] Example 4

[0076] The purpose of this embodiment is to provide an electronic device.

[0077] An electronic device includes a memory, a processor, and a program stored in the memory and executable on the processor, wherein the processor executes the program to implement the steps in the boundary condition-based engine knock control method as described in Embodiment 1 of this disclosure.

[0078] The steps and methods involved in the apparatuses of Embodiments 2, 3, and 4 above correspond to those in Embodiment 1. For specific implementation details, please refer to the relevant description section of Embodiment 1. The term "computer-readable storage medium" should be understood as a single medium or multiple media including one or more instruction sets; it should also be understood as including any medium capable of storing, encoding, or carrying an instruction set for execution by a processor and enabling the processor to perform any of the methods in this invention.

[0079] Those skilled in the art will understand that the modules or steps of the present invention described above can be implemented using general-purpose computer devices. Optionally, they can be implemented using computer-executable program code, thereby allowing them to be stored in a storage device for execution by a computer device, or they can be fabricated as separate integrated circuit modules, or multiple modules or steps can be fabricated as a single integrated circuit module. The present invention is not limited to any particular combination of hardware and software.

[0080] While the specific embodiments of the present invention have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art without creative effort based on the technical solutions of the present invention are still within the scope of protection of the present invention.

Claims

1. An engine knock control method based on boundary conditions, characterized in that, Includes the following steps: Engine operating parameters are selected as the first boundary condition, temperature parameters as the second boundary condition, and knock coefficient as the third boundary condition. Logical truth-false relationships are set for the first, second, and third boundary conditions. The method for calculating the knockout coefficient is as follows: Obtain the voltage signal from the knock sensor; Energy integration is performed on the detonation window and the reference window using Fourier transform, respectively; The ratio of the energy integral value of the detonation window to the energy integral value of the reference window is the detonation coefficient. The first boundary conditions include engine running time, intake manifold pressure, and engine speed; the second boundary conditions include coolant temperature, intake manifold temperature, and intake air temperature. When the engine running time, intake manifold pressure and engine speed in the first boundary condition all exceed the corresponding preset limits, the first boundary condition is determined to be true. When at least one of the water temperature, air intake pipe temperature and air intake temperature in the second boundary condition exceeds the corresponding preset limit, the second boundary condition is determined to be true. When the knock coefficient exceeds the corresponding preset limit, the third boundary condition is determined to be true; When the first boundary condition, the second boundary condition, and the third boundary condition are all true, calculate the sum of the water temperature corrected ignition angle, the intake manifold temperature corrected ignition angle, the intake air temperature corrected ignition angle, and the intake manifold pressure corrected ignition angle, and use it as the ignition angle correction value. The difference between the base ignition angle and the ignition angle correction value is calculated and used as the corrected engine ignition angle.

2. The engine knock control method based on boundary conditions as described in claim 1, characterized in that, When at least one of the first boundary condition, the second boundary condition, and the third boundary condition is not true, the engine ignition angle is obtained based on the basic ignition angle table.

3. The engine knock control method based on boundary conditions as described in claim 2, characterized in that, The basic ignition angle table is derived from engine speed and intake manifold pressure.

4. The engine knock control method based on boundary conditions as described in claim 1, characterized in that, The water temperature-corrected ignition angle, intake manifold temperature-corrected ignition angle, intake air temperature-corrected ignition angle, and intake manifold pressure-corrected ignition angle are obtained by referring to tables.

5. An engine knock control system based on boundary conditions, characterized in that: include: The boundary condition determination module is configured to: select engine operating parameters as the first boundary condition, temperature parameters as the second boundary condition, and knock coefficient as the third boundary condition, and set the logical truth-false judgment relationship between the first boundary condition, the second boundary condition, and the third boundary condition; The method for calculating the knockout coefficient is as follows: Obtain the voltage signal from the knock sensor; Energy integration is performed on the detonation window and the reference window using Fourier transform, respectively; The ratio of the energy integral value of the detonation window to the energy integral value of the reference window is the detonation coefficient. The first boundary conditions include engine running time, intake manifold pressure, and engine speed; the second boundary conditions include coolant temperature, intake manifold temperature, and intake air temperature. When the engine running time, intake manifold pressure and engine speed in the first boundary condition all exceed the corresponding preset limits, the first boundary condition is determined to be true. When at least one of the water temperature, air intake pipe temperature and air intake temperature in the second boundary condition exceeds the corresponding preset limit, the second boundary condition is determined to be true. When the knock coefficient exceeds the corresponding preset limit, the third boundary condition is determined to be true; The logic determination module is configured to: when the first boundary condition, the second boundary condition, and the third boundary condition are all true, calculate the sum of the water temperature corrected ignition angle, the intake manifold temperature corrected ignition angle, the intake air temperature corrected ignition angle, and the intake manifold pressure corrected ignition angle, and use it as the ignition angle correction value. The correction module is configured to calculate the difference between the base ignition angle and the ignition angle correction value, and use this difference as the corrected engine ignition angle.

6. A computer-readable storage medium having a program stored thereon, characterized in that, When executed by the processor, the program implements the steps in the boundary condition-based engine knock control method as described in any one of claims 1-4.

7. An electronic device, comprising a memory, a processor, and a program stored in the memory and executable on the processor, characterized in that, When the processor executes the program, it implements the steps in the boundary condition-based engine knock control method as described in any one of claims 1-4.

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