Knock detection method and device, computer equipment and storage medium

Abstract

The invention discloses a knock detection method, a knock detection device, computer equipment and a computer storage medium. The knock detection method comprises the steps that a pressure signal in an engine combustion chamber is acquired; obtaining the resonance frequency of engine knocking; decomposing the pressure signal into a high-frequency component signal and a low-frequency component signal according to an empirical mode decomposition method; obtaining the center frequency of the high-frequency component signal according to the high-frequency component signal; calculating a knock factor according to the low-frequency component signal and the high-frequency component signal in response to the fact that the center frequency is located within the range of the resonant frequency; comparing the knock factor with a knock threshold value of the engine, and judging that the engine is knocked in response to the fact that the knock factor is larger than or equal to the knock threshold value; and judging that the engine is not knocked in response to the fact that the center frequency is located outside the range of the resonance frequency or the knock factor is smaller than a knock threshold value. According to the knock detection method, whether the engine is knocked or not can be detected.

Description

Technical Field

[0001] The present invention relates to the field of engine technology, and in particular to a knock detection method, a knock detection device, a computer device and a computer storage medium. Background Art

[0002] This section merely provides background information related to the present disclosure and is not necessarily prior art.

[0003] Knocking is an abnormal combustion phenomenon of the engine. Knocking in the engine will reduce the engine's output power and torque. If the engine works in a knocking state for a long time, the engine's service life will be greatly reduced. In addition, knocking is a key factor that restricts the improvement of the engine's thermal efficiency.

[0004] However, the related art lacks an effective detection method, which results in an inability to effectively detect whether the engine is knocking. Summary of the invention

[0005] The purpose of the present invention is to at least solve the problem in the related art that it is not possible to effectively detect whether the engine is knocking. This purpose is achieved according to the following technical solutions:

[0006] The first aspect of the present invention proposes a knock detection method, comprising: obtaining a pressure signal in an engine combustion chamber; obtaining a resonant frequency of engine knock; decomposing the pressure signal into a high-frequency component signal and a low-frequency component signal according to an empirical mode decomposition method; obtaining a center frequency of the high-frequency component signal according to the high-frequency component signal; in response to the center frequency being within the range of the resonant frequency, calculating a knock factor according to the low-frequency component signal and the high-frequency component signal; comparing the knock factor with a knock threshold of the engine, and in response to the knock factor being greater than or equal to the knock threshold, determining that the engine has knocked; in response to the center frequency being outside the range of the resonant frequency, or in response to the knock factor being less than the knock threshold, determining that the engine has not knocked.

[0007] According to the knock detection method of the present invention, the pressure signal is decomposed into a high-frequency component signal and a low-frequency component signal, and the central frequency of the high-frequency pressure signal is compared with the resonance frequency of the knock to preliminarily determine whether the engine knocks, and the high-frequency component signal is used as a reference by the low-frequency component signal to obtain the knock factor, and the knock factor is compared with the knock threshold of the engine to further determine whether the engine knocks. In this way, it is possible to detect whether the engine knocks.

[0008] In addition, the knock detection method according to the present invention may also have the following additional technical features:

[0009] In some embodiments of the present invention, the step of obtaining the resonance frequency of engine knock includes: obtaining structural parameters of the engine combustion chamber; and calculating the resonance frequency according to the structural parameters.

[0010] In some embodiments of the present invention, the resonant frequency f is calculated by the following formula:

[0011]

[0012] where ρ η,δ is the vibration modal factor, B is the cylinder inner diameter of the engine, and c is the gas propagation velocity in the combustion chamber of the engine.

[0013] In some embodiments of the present invention, the step of obtaining the center frequency of the high-frequency component signal based on the high-frequency component signal includes: performing a fast Fourier transform on the high-frequency component signal to obtain a spectrum diagram of the high-frequency component signal; and obtaining the center frequency based on the spectrum diagram.

[0014] In some embodiments of the present invention, the step of calculating the knock factor based on the low-frequency component signal and the high-frequency component signal includes: obtaining a knock window starting point and a reference window end point based on the low-frequency component signal; obtaining a knock window duration and a reference window duration based on the high-frequency component signal; obtaining an integrated energy ratio of the high-frequency component signal in the knock window and the high-frequency component signal in the reference window based on the knock window starting point, the knock window duration, the reference window end point and the reference window duration, wherein the integrated energy ratio is the knock factor.

[0015] In some embodiments of the present invention, the integrated energy ratio K F Calculated according to the following formula:

[0016]

[0017] θ e represents the knock window starting point, θ s represents the end point of the reference window, Δθ e represents the duration of the knock window, Δθ s represents the duration of the reference window, |p k | represents the amplitude of the high-frequency component signal in the knock window, |p r | represents the amplitude of the high-frequency component signal in the reference window.

[0018] In some embodiments of the present invention, after acquiring the pressure signal in the engine combustion chamber and before decomposing the pressure signal into a high-frequency component signal and a low-frequency component signal according to an empirical mode decomposition method, the knock detection method includes: cleaning the pressure signal.

[0019] The second aspect of the present invention proposes a knock detection device, including an acquisition module, a decomposition module, a transformation module, an integration module, a comparison module and a judgment module. The acquisition module is used to acquire the pressure signal in the engine combustion chamber and the resonant frequency of the knock; the decomposition module is used to decompose the pressure signal into a high-frequency component signal and a low-frequency component signal; the transformation module is used to obtain the center frequency of the high-frequency component signal according to the high-frequency component signal; the integration module is used to obtain the knock factor according to the low-frequency component signal and the high-frequency component signal in response to the center frequency being within the range of the resonant frequency; the comparison module is used to compare the knock factor with the knock threshold of the engine, and judge that the engine has knocked in response to the knock factor being greater than or equal to the knock threshold; the judgment module is used to judge that the engine has not knocked in response to the center frequency being outside the range of the resonant frequency, or in response to the knock factor being less than the knock threshold.

[0020] The knock detection device of the present invention decomposes the pressure signal into a high-frequency component signal and a low-frequency component signal, compares the center frequency of the high-frequency pressure signal with the resonance frequency of the knock to preliminarily determine whether the engine has knocked, uses the low-frequency component signal as a reference for the high-frequency component signal to obtain a knock factor, and compares the knock factor with the knock threshold of the engine to further determine whether the engine has knocked, thereby being able to detect whether the engine has knocked.

[0021] The third invention of the present invention proposes a computer device, including a memory and a processor, wherein the memory stores a computer program, and when the processor executes the computer program, the steps of the knock detection method described in the first aspect above are implemented.

[0022] According to the computer device of the present invention, it is possible to detect whether knocking occurs in the engine.

[0023] A fourth aspect of the present invention provides a computer storage medium having computer-readable instructions stored thereon. When the computer-readable instructions are read by one or more processors, the one or more processors execute the knock detection method as described in the first aspect above.

[0024] According to the computer storage medium of the present invention, it is possible to detect whether knock occurs in the engine. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present invention. Also, the same reference numerals are used throughout the accompanying drawings to represent the same components. In the accompanying drawings:

[0026] Figure 1 is a flow chart of a knock detection method according to an embodiment of the present invention;

[0027] Figure 2 is a logic diagram of a knock detection method according to an embodiment of the present invention;

[0028] Figure 3 for Figure 1 Flow chart of step S400;

[0029] Figure 4 for Figure 1 Flow chart of step S500;

[0030] Figure 5 4 is a structural block diagram of a knock detection device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0031] The exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0032] It should be understood that the terms used herein are only for the purpose of describing specific example embodiments and are not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms "one", "an" and "said" as used herein may also be meant to include plural forms. The terms "include", "comprise", "contain", and "have" are inclusive, and therefore specify the existence of stated features, steps, operations, elements and / or parts, but do not exclude the existence or addition of one or more other features, steps, operations, elements, parts, and / or combinations thereof. The method steps, processes, and operations described herein are not interpreted as necessarily requiring them to be performed in the specific order described or illustrated, unless the execution order is clearly indicated. It should also be understood that additional or alternative steps may be used.

[0033] Although the terms first, second, third, etc. can be used in the text to describe multiple elements, components, regions, layers and / or sections, these elements, components, regions, layers and / or sections should not be limited by these terms. These terms can only be used to distinguish an element, component, region, layer or section from another region, layer or section. Unless the context clearly indicates, terms such as "first", "second" and other numerical terms do not imply order or sequence when used in the text. Therefore, the first element, component, region, layer or section discussed below can be referred to as the second element, component, region, layer or section without departing from the teaching of the example embodiments.

[0034] For ease of description, spatial relative terms may be used herein to describe the relationship of one element or feature relative to another element or feature as shown in the figure, such as "inside", "outside", "inner side", "outer side", "below", "below", "above", "above", etc. Such spatial relative terms are intended to include different orientations of the device in use or operation in addition to the orientation depicted in the figure. For example, if the device in the figure is turned over, then the elements described as "below other elements or features" or "below other elements or features" will subsequently be oriented as "above other elements or features" or "above other elements or features". Therefore, the example term "below..." can include both upper and lower orientations. The device can be oriented otherwise (rotated 90 degrees or in other directions) and the spatial relative descriptors used in the text are interpreted accordingly.

[0035] Knock is an abnormal combustion phenomenon of the engine. In the related technology, when the engine uses fuel with a low octane content (such as kerosene), the engine will produce knock during operation. Knock in the engine will reduce the output power and torque of the engine. If the engine works in a knock state for a long time, the service life of the engine will be greatly reduced. In addition, knock is a key factor that restricts the improvement of the thermal efficiency of the engine. Therefore, it is very important to use an effective knock detection method to detect the engine.

[0036] In order to at least solve the problem in the related art that it is not possible to effectively detect whether an engine is knocking, an embodiment of the present invention provides a knock detection method that can detect whether an engine is knocking.

[0037] like Figure 1 and Figure 2 As shown, the knock detection method of the embodiment of the present invention includes:

[0038] S100, obtaining a pressure signal in a combustion chamber of an engine;

[0039] S200, obtaining the resonance frequency of engine knock;

[0040] S300, decomposing the pressure signal into a high-frequency component signal and a low-frequency component signal according to an empirical mode decomposition method;

[0041] S400, obtaining a center frequency of the high-frequency component signal according to the high-frequency component signal;

[0042] S500, in response to the center frequency being within the range of the resonance frequency, calculating a knock factor according to a low-frequency component signal and a high-frequency component signal;

[0043] S600, comparing the knock factor with a knock threshold of the engine, and in response to the knock factor being greater than or equal to the knock threshold, determining that the engine has knocked;

[0044] S700: In response to the center frequency being outside the range of the resonance frequency, or in response to the knock factor being less than the knock threshold, determine that no knock occurs in the engine.

[0045] S100: Obtain a pressure signal in a combustion chamber of an engine.

[0046] In step S100, it is necessary to collect the pressure signal in the engine combustion chamber. As an optional implementation method, a pressure sensor is installed in the engine combustion chamber or in the engine exhaust system to obtain the pressure signal of the engine combustion chamber under different working conditions. The pressure signal can reflect the change information of the engine combustion process. Therefore, it can be determined whether the engine has knocked according to the pressure signal.

[0047] Optionally, the pressure sensor is a spark plug type pressure sensor, which transmits signals via a CAN bus (controller area network bus).

[0048] S200, obtaining the resonance frequency of engine knock;

[0049] When the engine detonates, the fuel will instantly release a large amount of energy and cause the engine to resonate. The resonance frequency caused by the detonation depends on the structural parameters of the engine combustion chamber. That is to say, for the same engine, the resonance frequency caused by the detonation is fixed.

[0050] In some embodiments, after step S100 and before step S300, the pressure signal is cleaned, in other words, the collected pressure signal is cleaned to remove noise, thereby reducing the interference of noise and increasing the accuracy of the knock detection method.

[0051] S300 , decomposing the pressure signal into a high-frequency component signal and a low-frequency component signal according to an empirical mode decomposition method.

[0052] Empirical Mode Decomposition (EMD) is an adaptive signal processing method that can decompose data according to its own characteristics and is suitable for processing nonlinear and non-stationary signals.

[0053] The empirical mode decomposition method can decompose the pressure signal into a series of intrinsic mode functions (IMFs), which represent components of different frequencies in the original signal. According to the frequency characteristics of the intrinsic mode function, it is classified into high-frequency signal components and low-frequency signal components. Among them, the spectrum obtained after the Fourier transform of the high-frequency signal component shows the energy concentration of the high-frequency part, and the spectrum obtained after the Fourier transform of the low-frequency signal component shows the energy concentration of the low-frequency part, thereby distinguishing the high-frequency signal component from the low-frequency signal component. In addition, the high-frequency signal component and the low-frequency signal component can also be simply distinguished according to the frequency of the intrinsic mode function. The high-frequency component signal can reflect the faster pressure changes during the combustion process. The low-frequency component signal can reflect the normal combustion process of the engine.

[0054] S400, obtaining a center frequency of the high-frequency component signal according to the high-frequency component signal;

[0055] The high-frequency component signal is further analyzed, and the center frequency in the high-frequency component signal is selected as the frequency segment for subsequent analysis to avoid interference from other frequency segments in the high-frequency component signal in subsequent analysis.

[0056] S500, in response to the center frequency being within the range of the resonance frequency, obtaining a knock factor according to the low-frequency component signal and the high-frequency component signal;

[0057] Determine whether the center frequency is within the range of the resonance frequency. If the center frequency is within the range of the resonance frequency, it means that the center frequency may be caused by knocking or other conditions other than knocking. Therefore, it is necessary to further determine whether the center frequency is caused by knocking, thereby reducing the probability of misjudgment. Further analyze the high-frequency component signal based on the low-frequency component signal as a reference to obtain the knock factor, so as to determine whether the engine has knocked in the subsequent steps by the knock factor.

[0058] S600: Compare the knock factor with a knock threshold of the engine, and in response to the knock factor being greater than or equal to the knock threshold, determine that engine knock occurs.

[0059] The knock threshold of the engine is determined by the parameters of the engine itself. For example, the knock threshold of some engines is 1.5. Comparing the knock factor and the knock threshold, when the knock factor is greater than or equal to the knock threshold, it means that the energy released by the fuel in the engine combustion chamber in a short period of time is too large, that is, the engine knocks.

[0060] S700: In response to the center frequency being outside the range of the resonance frequency, or in response to the knock factor being less than the knock threshold, determine that no knock occurs in the engine.

[0061] If the center frequency is outside the range of the resonance frequency, it means that the center frequency is not caused by knock. If the center frequency is within the resonance frequency and the knock factor is less than the knock threshold, it means that the center frequency is caused by other conditions other than knock, and the frequency generated by the other conditions is just within the resonance frequency.

[0062] The knock detection method of the embodiment of the present invention decomposes the pressure signal into a high-frequency component signal and a low-frequency component signal, compares the center frequency of the high-frequency pressure signal with the resonance frequency of the knock to preliminarily determine whether the engine knocks, uses the low-frequency component signal as a reference for the high-frequency component signal, thereby obtaining a knock factor, and further determines whether the engine knocks by comparing the knock factor with the knock threshold of the engine. In this way, it is possible to detect whether the engine knocks.

[0063] Specifically, the high-frequency component signal includes a first high-frequency component signal, a second high-frequency component signal, and a third high-frequency component signal. If the center frequency of at least one of the first high-frequency component signal, the second high-frequency component signal, and the third high-frequency component signal is within the range of the resonance frequency, and the knock factor obtained by the at least one is greater than or equal to the knock threshold, then the engine knocks. If the center frequency of each of the first high-frequency component signal, the second high-frequency component signal, and the third high-frequency component signal is outside the range of the resonance frequency, or the knock factor obtained by each of the first high-frequency component signal, the second high-frequency component signal, and the third high-frequency component signal is less than the knock threshold, then the engine does not knock.

[0064] In some embodiments, in step S200, the step of obtaining the resonance frequency of engine knock includes:

[0065] Obtaining structural parameters of the engine combustion chamber;

[0066] The resonance frequency is obtained based on the structural parameters.

[0067] The knock resonance frequency range is calculated based on the structural parameters of the engine combustion chamber, so that a preliminary judgment can be made as to whether the engine has knocked based on the resonance frequency.

[0068] In some specific embodiments, the resonant frequency f is calculated according to the following formula:

[0069]

[0070] where ρ η,δ is the vibration modal factor, where η represents the tangential mode number and δ represents the radial mode number. B is the cylinder bore of the engine and c is the gas propagation velocity in the engine combustion chamber.

[0071] Furthermore, the values ​​of η and δ are both 1, and the formula is simplified to:

[0072]

[0073] By simplifying the formula, the value of the resonant frequency can be quickly obtained.

[0074] For example, the gas sound velocity c is taken as 1000 m / s to further facilitate rapid calculation.

[0075] like Figure 3 As shown, in some embodiments, S400, obtaining the center frequency of the high-frequency component signal according to the high-frequency component signal, includes:

[0076] S410, performing fast Fourier transform on the high frequency component signal to obtain a frequency spectrum of the high frequency component signal;

[0077] S420, obtaining a center frequency according to the spectrum diagram.

[0078] S410, performing fast Fourier transform on the high frequency component signal to obtain a frequency spectrum of the high frequency component signal.

[0079] Fast Fourier Transform (FFT) is an efficient algorithm for calculating Discrete Fourier Transform (DFT). Fast Fourier Transform is the process of converting time domain signals into frequency domain signals. According to Fast Fourier Transform, the spectrum of high frequency component signals can be obtained. The spectrum is a graph that represents the frequency components of the signal and can show the signal strength at different frequencies.

[0080] Optionally, before step S410, the high frequency component signal is filtered and denoised to reduce interference factors, thereby increasing the accuracy of knock detection.

[0081] S420, obtaining a center frequency according to the spectrum diagram.

[0082] Find the part with the highest energy in the spectrum graph, that is, the peak of the spectrum graph, and determine the center frequency based on the peak value or use the peak value as the center frequency. The center frequency is used as the frequency segment for subsequent analysis to avoid interference from other frequency segments in the high-frequency component signal in subsequent analysis.

[0083] like Figure 4As shown, in some embodiments, S500, calculating the knock factor according to the low-frequency component signal and the high-frequency component signal, includes:

[0084] S510, obtaining a knock window starting point and a reference window end point according to the low-frequency component signal;

[0085] S520, obtaining the duration of the knock window according to the high-frequency component signal and the duration of the reference window;

[0086] S530. Obtain the knock window starting point, the knock window duration, the reference window end point and the reference window duration according to the low-frequency component signal, and obtain the integrated energy ratio of the high-frequency component signal in the knock window and the high-frequency component signal in the reference window, wherein the integrated energy ratio is the knock factor.

[0087] S510 , obtaining a knock window start point and a reference window end point according to a low-frequency component signal.

[0088] The knock window refers to the operating area of ​​the engine where knock is likely to occur under certain specific operating conditions (such as specific speed, load and intake temperature, etc.). The knock window indicates that under these operating conditions, the combustion process may be unstable, resulting in the occurrence of knock. The size and position of the knock window may vary depending on the engine design, fuel properties and tuning settings.

[0089] The reference window is usually used as a benchmark area for judgment and comparison, usually an ideal working area without knock. This window can be used to provide a relative standard to help identify and analyze the occurrence of knock, such as judging whether the engine is in good working condition by monitoring the deviation between the actual working state and the reference window.

[0090] The knock window start point and the reference window end point are both determined according to the crankshaft angle corresponding to the amplitude of the low-frequency signal.

[0091] S520, obtaining the duration of the knock window according to the high-frequency component signal and the duration of the reference window;

[0092] The duration of the knock window and the duration of the reference window are both determined according to the continuous oscillation time of the high-frequency component. For example, the duration of the knock window and the duration of the reference window are both between 40° and 60°.

[0093] S520. Obtain an integrated energy ratio of a high-frequency component signal in the knock window and a high-frequency component signal in the reference window according to the knock window starting point, the knock window duration, the reference window end point, and the reference window duration, wherein the integrated energy ratio is a knock factor.

[0094] The knock window can be determined based on the knock window starting point and the knock window duration, and the integration of the high-frequency component signal in the knock window can reflect the rapid combustion state in the knock window. The reference window can be determined based on the reference window starting point and the reference window duration, and the integration of the high-frequency component signal in the reference window can reflect the normal combustion state of the engine. The integrated energy ratio of the high-frequency component signal in the knock window and the high-frequency component signal in the reference window, i.e., the knock factor, can reflect the severity of the rapid combustion state in the knock window relative to the normal combustion state.

[0095] It is understandable that the larger the knock factor, the more intense the rapid combustion in the engine. Therefore, by comparing the knock factor and the engine knock threshold, it is possible to determine whether the engine has knocked. In addition, when the engine has knocked, the degree of knock can also be determined based on the size of the knock factor. The larger the knock factor, the greater the degree of engine knock.

[0096] In some embodiments, the integrated energy ratio K F Calculated according to the following formula:

[0097]

[0098] θ e represents the knock window starting point, θ s represents the end point of the reference window, Δθ e represents the duration of the knock window, Δθ s represents the duration of the reference window, |p k | represents the amplitude of the high-frequency component signal in the knock window, |p r | represents the amplitude of the high-frequency component signal within the reference window. represents the integral of the high-frequency component signal within the knock window, Represents the integral of the high-frequency component signal within the reference window.

[0099] It should be understood that, although the various steps in the flowcharts involved in the above-mentioned embodiments are displayed in sequence according to the indication of the arrows, these steps are not necessarily executed in sequence according to the order indicated by the arrows. Unless there is a clear explanation in this article, the execution of these steps does not have a strict order restriction, and these steps can be executed in other orders. Moreover, at least a part of the steps in the flowcharts involved in the above-mentioned embodiments can include multiple steps or multiple stages, and these steps or stages are not necessarily executed at the same time, but can be executed at different times, and the execution order of these steps or stages is not necessarily to be carried out in sequence, but can be executed in turn or alternately with other steps or at least a part of the steps or stages in other steps.

[0100] Based on the same inventive concept, the embodiment of the present application further provides a knock detection device 100 for implementing the knock detection method involved above. The implementation scheme for solving the problem provided by the device is similar to the implementation scheme recorded in the above method, so the specific limitations in one or more knock detection device embodiments provided below can refer to the limitations on the label classification method above, and will not be repeated here.

[0101] like Figure 5 As shown, the knock detection device 100 of the embodiment of the present invention comprises:

[0102] An acquisition module 110 is used to acquire a pressure signal in a combustion chamber of an engine and a resonance frequency of knock;

[0103] A decomposition module 120, used for decomposing the pressure signal into a high-frequency component signal and a low-frequency component signal;

[0104] A transformation module 130, configured to obtain a center frequency of the high frequency component signal according to the high frequency component signal;

[0105] An integration module 140, for calculating a knock factor according to a low frequency component signal and a high frequency component signal in response to the center frequency being within the range of the resonance frequency;

[0106] A comparison module 150 is used to compare the knock factor with the knock threshold of the engine, and when the knock factor is greater than or equal to the knock threshold, it is determined that the engine has knocked;

[0107] The judgment module 160 is configured to judge that no knock occurs in the engine in response to the center frequency being outside the range of the resonance frequency or in response to the knock factor being less than the knock threshold.

[0108] The knock detection device 100 of the embodiment of the present invention decomposes the pressure signal into a high-frequency component signal and a low-frequency component signal, compares the center frequency of the high-frequency pressure signal with the resonance frequency of the knock to preliminarily determine whether the engine has knock, uses the low-frequency component signal as a reference for the high-frequency component signal to obtain a knock factor, and compares the knock factor with the knock threshold of the engine to further determine whether the engine has knock, thereby being able to detect whether the engine has knock.

[0109] In some embodiments, the acquisition module 110 is further used to acquire structural parameters of the engine combustion chamber, and obtain the resonance frequency according to the structural parameters.

[0110] In some embodiments, the transformation module 130 is further used to perform a fast Fourier transform on the high-frequency component signal to obtain a frequency spectrum of the high-frequency component signal; and obtain the center frequency according to the frequency spectrum.

[0111] In some embodiments, the integration module 140 is also used to obtain the knock window starting point, the knock window duration, the reference window end point and the reference window duration according to the low-frequency component signal, obtain the knock window starting point, the knock window duration, the reference window end point and the reference window duration according to the low-frequency component signal, and obtain the integrated energy ratio of the high-frequency component signal in the knock window and the high-frequency component signal in the reference window, wherein the integrated energy ratio is the knock factor.

[0112] Those skilled in the art will understand that Figure 5 The structure shown in the figure is only a block diagram of a part of the structure related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. The specific computer device may include more or fewer components than those shown in the figure, or combine certain components, or have a different arrangement of components.

[0113] An embodiment of the present invention further proposes a computer device, including a memory and a processor, wherein the memory stores a computer program, and when the processor executes the computer program, the steps of the knock detection method of the above embodiment are implemented to detect whether knock occurs in the engine.

[0114] Furthermore, the computer device includes a processor, a memory, an input / output interface (Input / Output, referred to as I / O) and a communication interface. The processor, the memory and the input / output interface are connected according to the system bus, and the communication interface is connected to the system bus according to the input / output interface. The processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program and a database. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The input / output interface of the computer device is used to exchange information between the processor and an external device. The communication interface of the computer device is used to communicate with an external terminal according to a network connection. When the computer program is executed by the processor, the above-mentioned knock detection method is implemented to detect whether the engine has knocked.

[0115] An embodiment of the present invention further proposes a computer storage medium, characterized in that computer readable instructions are stored on the computer storage medium. When the computer readable instructions are read by one or more processors, the one or more processors execute the steps of the knock detection method of the above embodiment to detect whether knock occurs in the engine.

[0116] The logic and / or steps represented in the flowchart or otherwise described herein, for example, may be considered as an ordered list of executable instructions for implementing logical functions, and may be embodied in any computer-readable storage medium for use by an instruction execution system, apparatus, or device (such as a computer-based system, a system including a processor, or other system that can fetch instructions from an instruction execution system, apparatus, or device and execute instructions), or in conjunction with such instruction execution system, apparatus, or device. For purposes of this specification, a "computer-readable storage medium" may be any device that can contain, store, communicate, propagate, or transmit a program for use by an instruction execution system, apparatus, or device, or in conjunction with such instruction execution system, apparatus, or device. More specific examples of computer-readable storage media (a non-exhaustive list) include the following: an electrical connection with one or more wirings (electronic devices), a portable computer disk case (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM, Erasable Programmable Read-Only Memory, or flash memory), an optical fiber device, and a portable compact disc read-only memory (CDROM, Compact Disc Read-Only Memory). In addition, the computer-readable storage medium may even be a paper or other suitable medium on which the program is printed, since the program may be obtained electronically, for example, by optically scanning the paper or other medium, followed by editing, deciphering, or processing in another suitable manner as necessary, and then stored in a computer memory.

[0117] It should be understood that the various parts of the present invention can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiment, a plurality of steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA, Programmable Gate Array), a field programmable gate array (FPGA, Field Programmable Gate Array), etc.

[0118] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. A knock detection method, characterized in that: include: Obtaining the pressure signal in the engine combustion chamber; Obtain the resonant frequency of engine knock; Decomposing the pressure signal into a high-frequency component signal and a low-frequency component signal according to an empirical mode decomposition method; Obtaining the center frequency of the high frequency component signal according to the high frequency component signal; In response to the center frequency being within the range of the resonance frequency, calculating a knock factor based on the low-frequency component signal and the high-frequency component signal; comparing the knock factor with a knock threshold of the engine, and in response to the knock factor being greater than or equal to the knock threshold, determining that knock occurs in the engine; In response to the center frequency being outside the range of the resonance frequency, or in response to the knock factor being less than the knock threshold, it is determined that no knock occurs in the engine.

2. The knock detection method according to claim 1, characterized in that: The step of obtaining the resonance frequency of engine knock comprises: Acquiring structural parameters of the engine combustion chamber; The resonant frequency is calculated based on the structural parameters.

3. The knock detection method according to claim 2, characterized in that: The resonant frequency f is calculated by the following formula: where ρ η,δ is the vibration modal factor, B is the cylinder inner diameter of the engine, and c is the gas propagation velocity in the combustion chamber of the engine.

4. The knock detection method according to claim 1, characterized in that: The step of obtaining the center frequency of the high-frequency component signal according to the high-frequency component signal comprises: Performing a fast Fourier transform on the high frequency component signal to obtain a frequency spectrum of the high frequency component signal; The center frequency is obtained according to the spectrum diagram.

5. The knock detection method according to claim 1, characterized in that: The step of calculating the knock factor according to the low-frequency component signal and the high-frequency component signal comprises: Obtaining a knock window starting point and a reference window end point according to the low-frequency component signal; Obtaining a duration of a knock window and a duration of a reference window according to the high frequency component signal; According to the knock window starting point, the duration of the knock window, the reference window end point and the duration of the reference window, the integrated energy ratio of the high-frequency component signal in the knock window and the high-frequency component signal in the reference window is obtained, wherein the integrated energy ratio is the knock factor.

6. The knock detection method according to claim 5, characterized in that: The integrated energy ratio K F Calculated according to the following formula: θ e represents the knock window starting point, θ s represents the end point of the reference window, Δθ e represents the duration of the knock window, Δθ s represents the duration of the reference window, |p k | represents the amplitude of the high-frequency component signal in the knock window, |p r | represents the amplitude of the high-frequency component signal in the reference window.

7. The knock detection method according to claim 1, characterized in that: After acquiring the pressure signal in the engine combustion chamber and before decomposing the pressure signal into a high-frequency component signal and a low-frequency component signal according to the empirical mode decomposition method, the knock detection method includes: The pressure signal is cleaned.

8. A knock detection device, characterized in that: include: An acquisition module, used for acquiring a pressure signal in a combustion chamber of an engine and a resonance frequency of knock; A decomposition module, used for decomposing the pressure signal into a high-frequency component signal and a low-frequency component signal; A transformation module, used for obtaining the center frequency of the high-frequency component signal according to the high-frequency component signal; an integration module, configured to calculate a knock factor through the low-frequency component signal and the high-frequency component signal in response to the center frequency being within the range of the resonance frequency; a comparison module, configured to compare the knock factor with a knock threshold of the engine, and in response to the knock factor being greater than or equal to the knock threshold, determine that knock occurs in the engine; The judgment module is used for judging that no knock occurs in the engine in response to the center frequency being outside the range of the resonance frequency or in response to the knock factor being less than the knock threshold.

9. A computer device, characterized in that: The method comprises a memory and a processor, wherein the memory stores a computer program, and the processor implements the steps of the knock detection method according to any one of claims 1 to 7 when executing the computer program.

10. A computer storage medium, characterized in that: Computer-readable instructions are stored on the computer storage medium. When the computer-readable instructions are read by one or more processors, the one or more processors are caused to execute the steps of the knock detection method according to any one of claims 1 to 7.

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