Knock detection method and device, computer device and storage medium

Abstract

The application discloses a knock detection method, a knock detection device, computer equipment and a computer storage medium, wherein the knock detection method comprises the following steps: acquiring a pressure signal in an engine combustion chamber; acquiring a resonance 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 located in a range of the resonance 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 value of the engine, and in response to the knock factor being greater than or equal to the knock threshold value, judging that the engine knocks; and in response to the center frequency being located outside the range of the resonance frequency, or in response to the knock factor being less than the knock threshold value, judging that the engine does not knock. The knock detection method can detect whether the engine knocks.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of engines, and particularly relates to a knock detection method, a knock detection device, a computer device and a computer storage medium. BACKGROUND

[0002] The part provided in this section is merely background information related to the present disclosure, which does not necessarily have to be prior art.

[0003] Knock is a kind of abnormal combustion phenomenon of an engine, and the output power and torque of the engine will be reduced when knock occurs in the engine. If the engine works in the state of knock for a long time, the service life of the engine will be greatly reduced. In addition, knock is a key factor restricting the improvement of the thermal efficiency of the engine.

[0004] However, there is a lack of effective detection method in the related art, which leads to the inability to effectively detect whether the engine knocks. SUMMARY

[0005] The purpose of the present application is to at least solve the problem that the engine cannot be effectively detected in the related art. The purpose is achieved according to the following technical solutions:

[0006] The first aspect of the present application provides a knock detection method, comprising: acquiring a pressure signal in a combustion chamber of an engine; acquiring a resonance frequency of knock of the engine; 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 located in a range of the resonance 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, judging that the engine knocks; and in response to the center frequency being located outside the range of the resonance frequency, or in response to the knock factor being less than the knock threshold, judging that the engine does not knock.

[0007] According to the knock detection method of the present application, the pressure signal is decomposed into a high-frequency component signal and a low-frequency component signal, the center frequency of the high-frequency pressure signal is compared with the resonance frequency of knock to preliminarily judge whether the engine knocks, the high-frequency component signal is taken as a reference by the low-frequency component signal to obtain a knock factor, and the knock factor is compared with the knock threshold of the engine to further judge whether the engine knocks. Therefore, whether the engine knocks can be detected.

[0008] In addition, the knock detection method according to the present application can have the following additional technical features:

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

[0010] In some embodiments of the present application, the resonance frequency f is calculated according to the following formula:

[0011]

[0012] wherein p η,δ is a vibration mode factor, B is the inner diameter of the cylinder of the engine, and c is the propagation speed of gas in the combustion chamber of the engine.

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

[0014] In some embodiments of the present application, the step of calculating the knock factor according to the low-frequency component signal and the high-frequency component signal comprises: obtaining a start point of a knock window and an end point of a reference window according to the low-frequency component signal; obtaining a duration of the knock window and a duration of the reference window according to the high-frequency component signal; and obtaining an integral energy ratio of the high-frequency component signal in the knock window and the high-frequency component signal in the reference window according to the start point of the knock window, the duration of the knock window, the end point of the reference window, and the duration of the reference window, wherein the integral energy ratio is the knock factor.

[0015] In some embodiments of the present application, the integral energy ratio K F is calculated according to the following formula:

[0016]

[0017] θ e represents the start point of the knock window, 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 application, after obtaining the pressure signal in the combustion chamber of the engine, and before decomposing the pressure signal into the high-frequency component signal and the low-frequency component signal according to the empirical mode decomposition method, the knock detection method comprises: cleaning the pressure signal.

[0019] A second aspect of the present application provides a knock detection device, comprising an obtaining module, a decomposing module, a transforming module, an integrating module, a comparing module and a judging module. The obtaining module is configured to obtain a pressure signal in a combustion chamber of an engine and a resonance frequency of knock. The decomposing module is configured to decompose the pressure signal into a high-frequency component signal and a low-frequency component signal. The transforming module is configured to obtain a center frequency of the high-frequency component signal according to the high-frequency component signal. The integrating module is configured to obtain a knock factor according to the low-frequency component signal and the high-frequency component signal in response to the center frequency being within a range of the resonance frequency. The comparing module is configured to compare the knock factor with a knock threshold of the engine, and to judge that the engine knocks in response to the knock factor being greater than or equal to the knock threshold. The judging module is configured to judge that the engine does not knock 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.

[0020] The knock detection device of the present application decomposes the pressure signal into the high-frequency component signal and the low-frequency component signal, compares the center frequency of the high-frequency pressure signal with the resonance frequency of knock to preliminarily judge whether the engine knocks, obtains the knock factor according to the low-frequency component signal as a reference to the high-frequency component signal, and further judges whether the engine knocks according to the comparison between the knock factor and the knock threshold of the engine, thereby being able to detect whether the engine knocks.

[0021] A third aspect of the present application provides a computer device, comprising 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 the first aspect when executing the computer program.

[0022] The computer device according to the present application is able to detect whether the engine knocks.

[0023] A fourth aspect of the present application provides a computer storage medium, wherein the computer storage medium stores computer readable instructions, and the computer readable instructions make one or more processors execute the knock detection method according to the first aspect when being read by the one or more processors.

[0024] The computer storage medium according to the present application is able to detect whether the engine knocks. BRIEF DESCRIPTION OF DRAWINGS

[0025] Various other advantages and benefits will become apparent to those skilled in the art from the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

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

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

[0028] Figure 3 for Figure 1 Flowchart of step S400;

[0029] Figure 4 for Figure 1 Flowchart of step S500;

[0030] Figure 5 This is a structural block diagram of the knock detection device according to an embodiment of the present invention. Detailed Implementation

[0031] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

[0032] It should be understood that the terminology used herein is for the purpose of describing particular exemplary embodiments only and is not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms “a,” “an,” and “described” as used herein may also include the plural forms. The terms “comprising,” “including,” “containing,” and “having” are inclusive and therefore indicate the presence of the stated features, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, elements, components, and / or combinations thereof. The method steps, processes, and operations described herein are not construed as requiring them to be performed in a particular order described or illustrated unless the order of performance is explicitly 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 herein to describe various 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 be only used to distinguish one element, component, region, layer or section from another region, layer or section. Unless the context clearly indicates otherwise, terms such as "first", "second" and the like used herein do not imply a sequence or an order, but are used to distinguish one element, component, region, layer or section from another element, component, region, layer or section. Thus, a first element, component, region, layer or section discussed below can be termed a second element, component, region, layer or section without departing from the teachings of the example embodiments.

[0034] For ease of description, spatial relative terms can be used herein to describe a relationship of one element or feature to another element or feature as shown in the drawings, such as "inner", "outer", "inside", "outside", "lower", "below", "upper", "above", and the like. 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 drawings. For example, if the device in the drawings is turned over, an element described as "below" or "under" another element or feature would then be oriented "above" or "over" the other element or feature. Thus, the example term "below" can include both an up and a down orientation. The device can be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

[0035] Knocking is an abnormal combustion phenomenon of an engine. In the related art, when an engine uses fuel with a low octane content (e.g., kerosene), the engine produces knocking during operation. The knocking in the engine reduces the output power and torque of the engine. The engine has a greatly reduced service life when working in a knocking state for a long time. In addition, knocking is a key factor restricting the improvement of the thermal efficiency of the engine. Therefore, it is very important to detect the engine by using an effective knocking detection method.

[0036] To at least solve the problem that the engine knocking cannot be effectively detected in the related art, an embodiment of the present application provides a knocking detection method, which can detect whether the engine knocks.

[0037] As shown in Figure 1 and Figure 2 , the knocking detection method provided by the embodiment of the present application comprises:

[0038] S100, acquiring a pressure signal in a combustion chamber of the engine;

[0039] S200, acquiring a resonance frequency of the engine knocking;

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

[0041] S400, obtain 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 located in a range of the resonance frequency, calculate a knock factor according to the low-frequency component signal and the high-frequency component signal;

[0043] 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 the engine knocks;

[0044] S700, in response to the center frequency being located out of the range of the resonance frequency, or in response to the knock factor being less than the knock threshold, determine that the engine does not knock.

[0045] S100, obtain a pressure signal in a combustion chamber of an engine.

[0046] In step S100, the pressure signal in the combustion chamber of the engine needs to be collected. As an optional implementation manner, a pressure sensor is installed in the combustion chamber of the engine or in an exhaust system of the engine, so as 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, and thus, the engine knock can be determined according to the pressure signal.

[0047] Optionally, the pressure sensor is a spark plug type pressure sensor, and the signal is transmitted through a can bus (controller area network bus).

[0048] S200, obtain a resonance frequency of engine knock;

[0049] When the engine knocks, a large amount of energy is released instantaneously by the fuel and the engine produces resonance. The resonance frequency produced by the knock depends on the structural parameters of the engine combustion chamber, that is, for the same engine, the resonance frequency produced by the knock 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, so as to remove noise, thereby reducing the interference of noise and increasing the accuracy of the knock detection method.

[0051] S300, decompose 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, which can decompose data according to its own characteristics, and is suitable for processing nonlinear and non-stationary signals.

[0053] The pressure signal can be decomposed into a series of Intrinsic Mode Functions (IMFs) by the Empirical Mode Decomposition method, and the Intrinsic Mode Functions represent different frequency components in the original signal. According to the frequency characteristics of the Intrinsic Mode Functions, they can be classified into high-frequency signal components and low-frequency signal components. The frequency spectrum obtained by Fourier transform of the high-frequency signal component shows that the energy is concentrated in the high-frequency part, and the frequency spectrum obtained by Fourier transform of the low-frequency signal component shows that the energy is concentrated in the low-frequency part, so the high-frequency signal component and the low-frequency signal component can be distinguished. In addition, the high-frequency signal component and the low-frequency signal component can also be distinguished simply according to the frequency of the Intrinsic Mode Functions. The high-frequency component signal can reflect the rapid pressure change in 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 band for subsequent analysis, so as to avoid interference in subsequent analysis of other frequency bands in the high-frequency component signal.

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

[0057] It is judged whether the center frequency is located in the range of the resonance frequency. If the center frequency is located in the range of the resonance frequency, it means that the center frequency may be generated by knock or other conditions except knock, so it is necessary to further judge whether the center frequency is generated by knock, so as to reduce the probability of misjudgment. The low-frequency component signal is used as a reference to further analyze the high-frequency component signal, and a knock factor is obtained, so as to judge whether the engine knocks in the subsequent step through the knock factor.

[0058] 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, judging that the engine knocks.

[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. By comparing the knock factor with the knock threshold, when the knock factor is greater than or equal to the knock threshold, it indicates that the energy released by the fuel in the combustion chamber of the engine in a short 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, determining that the engine does not knock.

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

[0062] The knock detection method of the embodiment of the present application 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, takes 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 knocks. Thus, it can be determined 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. 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. 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 the engine knock includes:

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

[0066] Obtaining the resonance frequency according to the structural parameters.

[0067] The resonance frequency range is calculated according to the obtained structural parameters of the combustion chamber of the engine, so as to facilitate the subsequent preliminary determination of whether the engine knocks according to the resonance frequency.

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

[0069]

[0070] wherein p η,δ is the vibration mode factor, wherein η represents the tangential mode number, δ represents the radial mode number. B is the cylinder bore of the engine, c is the gas propagation speed in the combustion chamber of the engine.

[0071] Further, the values of η and δ are both taken as 1, and the formula is simplified as:

[0072]

[0073] According to the simplification of the formula, the value of the resonance frequency can be quickly obtained.

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

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

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

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

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

[0079] Fast Fourier transform (FFT) is an efficient algorithm for computing discrete Fourier transform (DFT), which is the process of converting time-domain signals into frequency-domain signals. According to the fast Fourier transform, the frequency spectrum diagram of the high-frequency component signal can be obtained. The frequency spectrum diagram is a graph representing the frequency components of the signal, which can display the signal intensity at different frequencies.

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

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

[0082] Find the part with the highest energy in the frequency spectrum diagram, i.e. the peak value of the frequency spectrum diagram, and determine the center frequency according to the peak value or take the peak value as the center frequency. The center frequency is used as the frequency band for subsequent analysis to avoid interference from other frequency bands in the high-frequency component signal in subsequent analysis.

[0083] As Figure 4In some embodiments, S500, the knock factor is calculated according to the low-frequency component signal and the high-frequency component signal, including:

[0084] S510, the knock window start point and the reference window end point are obtained according to the low-frequency component signal.

[0085] S520, the duration of the knock window and the duration of the reference window are obtained according to the high-frequency component signal.

[0086] S530, the knock window start point, the duration of the knock window, the reference window end point and the duration of the reference window are obtained according to the low-frequency component signal, and the integral 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 integral energy ratio is the knock factor.

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

[0088] The knock window refers to the operating region of the engine under certain specific operating conditions (such as specific speed, load and intake temperature, etc.), which is prone to knock. The knock window indicates that under these conditions, the combustion process may be unstable, leading to the occurrence of knock phenomenon. 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 a reference region for judgment and comparison, and is usually an operating region under ideal conditions 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 according to the deviation between the monitored actual working condition and the reference window.

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

[0091] S520, the duration of the knock window and the duration of the reference window are obtained according to the high-frequency component signal.

[0092] The duration of the knock window and the duration of the reference window are determined according to the duration 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, the knock window start point, the duration of the knock window, the reference window end point and the duration of the reference window are obtained, and the integral 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 integral energy ratio is the knock factor.

[0094] The knock window can be determined according to a knock window start point and a knock window duration, and the integral of the high frequency component signal within the knock window can reflect the rapid combustion state within the knock window. The reference window can be determined according to a reference window start point and a reference window duration, and the integral of the high frequency component signal within the reference window can reflect the normal combustion state of the engine. The integral energy ratio of the high frequency component signal within the knock window to the high frequency component signal within the reference window, i.e., the knock factor, can reflect the severity of the rapid combustion state within the knock window relative to the normal combustion state.

[0095] It can be understood that the greater the knock factor, the more severe the rapid combustion within the engine, and thus, according to the comparison of the size of the knock factor and the engine knock threshold, it can be determined whether the engine knocks. In addition, when the engine knocks, according to the size of the knock factor, it can also be determined the severity of the knock, the greater the knock factor, the greater the severity of the engine knock.

[0096] In some embodiments, the integral energy ratio K F The integral energy ratio K is calculated according to the following formula:

[0097]

[0098] θ e represents the knock window start 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 within 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 each step in the flowchart involved in each of the above-described embodiments is shown in sequence according to the direction of the arrow, these steps are not necessarily executed in sequence according to the direction of the arrow. Unless otherwise specified herein, the execution of these steps is not strictly limited in sequence, and these steps can be executed in other sequences. Moreover, at least part of the steps in the flowchart involved in each of the above-described embodiments can include multiple steps or multiple stages, which are not necessarily executed at the same time, but can be executed at different times, and the execution sequence of these steps or stages is not necessarily sequential, but can be executed in rotation or alternation with at least part of other steps or steps or stages in other steps.

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

[0101] As shown in FIG. 1, the knock detection device 100 of the embodiment of the application comprises: Figure 5

[0102] The acquisition module 110 is configured to acquire a pressure signal in the combustion chamber of the engine and a resonance frequency of the knock.

[0103] The decomposition module 120 is configured to decompose the pressure signal into a high-frequency component signal and a low-frequency component signal.

[0104] The transformation module 130 is configured to obtain a center frequency of the high-frequency component signal according to the high-frequency component signal.

[0105] The integration module 140 is configured to calculate a 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 resonance frequency.

[0106] The comparison module 150 is configured to compare the knock factor with a knock threshold of the engine, and determine that the engine knocks when the knock factor is greater than or equal to the knock threshold.

[0107] The determination module 160 is configured to determine that the engine does not knock 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 application 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 to obtain a knock factor, and further determines whether the engine knocks by comparing the knock factor with the knock threshold of the engine, thereby being able to detect whether the engine knocks.

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

[0110] In some embodiments, the transformation module 130 is further configured 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 further configured to obtain the knock window start point, the duration of the knock window, the reference window end point and the duration of the reference window according to the low frequency component signal, obtain the integration energy ratio of the high frequency component signal within the knock window and the high frequency component signal within the reference window according to the low frequency component signal, and the integration energy ratio is the knock factor.

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

[0113] Embodiments of the present application also propose a computer device comprising a memory and a processor, the memory stores a computer program, and the processor implements the steps of the knock detection method of the above-mentioned embodiments when executing the computer program, so as to be able to detect whether the engine knocks.

[0114] Further, the computer device comprises 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 a 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 comprises 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 operating system and the computer program in the non-volatile storage medium to run. The input / output interface of the computer device is used to exchange information between the processor and external devices. The communication interface of the computer device is used to communicate with external terminals according to network connection. The computer program is executed by the processor to implement the above-mentioned knock detection method, so as to be able to detect whether the engine knocks.

[0115] Embodiments of the present application also propose a computer storage medium, characterized in that the computer storage medium stores computer readable instructions, and the computer readable instructions are read by one or more processors to make the one or more processors execute the steps of the knock detection method of the above-mentioned embodiments, so as to be able to detect whether the engine knocks.

[0116] The logic and / or steps represented in flow diagrams or otherwise described herein, for example, can be considered as a sequence of executable instructions, and can be embodied in any computer-readable storage medium for use by or in connection with an instruction execution system, apparatus, or device, such as a computer-based system, processor-containing system, or other system that can fetch the instructions from the instruction execution system, apparatus, or device and execute the instructions. For purposes of this specification, a "computer-readable storage medium" can be any apparatus that can contain, store, communicate, propagate, or transport the program for use by or in connection with the instruction execution system, apparatus, or device. The computer-readable storage medium can specifically include the following: electrical connection (electrical) having one or more wires, a portable computer diskette (magnetic), a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM) or flash memory, an optical fiber, and a portable compact disc read-only memory (CDROM). In addition, the computer-readable storage medium can even be the paper or other suitable medium upon which the program can be printed, since the program can be electronically obtained, for example, by optically scanning the paper or other medium, then

[0117] It should be understood that portions of the application can be implemented in hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented in software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented in hardware, and as in another embodiment, any of the following technologies known in the art, or a combination thereof, can be used: discrete logic circuitry having logic gates for implementing logic functions on data signals, application specific integrated circuits having appropriate combinational logic gates, programmable gate arrays (PGA), field programmable gate arrays (FPGA), and the like.

[0118] The above merely describes preferred specific embodiments of the present application, but the protection scope of the present application is not limited thereto, any changes or replacements within the technical scope disclosed by the present application, which can be easily thought by those skilled in the art, should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A knock detection method characterized by, The method comprises: obtaining a pressure signal in an engine combustion chamber; obtaining a resonance 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 a range of the resonance 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 knocks; 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, determining that the engine does not knock.

2. The knock detection method according to claim 1, characterized by, The step of obtaining the resonance frequency of engine knock comprises: obtaining a structural parameter of the engine combustion chamber; calculating the resonance frequency according to the structural parameter.

3. The knock detection method according to claim 2, characterized by, The resonance frequency f is calculated according to the following formula: where p η,δ is the vibration mode factor, B is the cylinder bore of the engine, and c is the gas propagation speed in the combustion chamber of the engine.

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

5. The knock detection method according to claim 1, characterized by, 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 start point and a reference window end point according to the low-frequency component signal; obtaining a duration of the knock window and a duration of the reference window according to the high-frequency component signal; obtaining an integral energy ratio of the high-frequency component signal in the knock window to the high-frequency component signal in the reference window according to the knock window start point, the duration of the knock window, the reference window end point and the duration of the reference window, wherein the integral energy ratio is the knock factor.

6. The knock detection method according to claim 5, characterized by, The integrated energy ratio K F is calculated according to the following formula: θ e represents the start of the knock window, θ s represents the end 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 within the knock window, |p r | represents the amplitude of the high frequency component signal within the reference window.

7. The knock detection method according to claim 1, characterized by, After obtaining the pressure signal in the engine combustion chamber and before decomposing the pressure signal into the high-frequency component signal and the low-frequency component signal according to the empirical mode decomposition method, the knock detection method comprises: cleaning the pressure signal.

8. An explosion detection device characterized by comprising: The method comprises: an obtaining module, configured to obtain a pressure signal in an engine combustion chamber and a resonance frequency of knock; a decomposing module, configured to decompose the pressure signal into a high-frequency component signal and a low-frequency component signal; a transforming module, configured to obtain a center frequency of the high-frequency component signal according to the high-frequency component signal; an integral module, configured to calculate a knock factor according to the low-frequency component signal and the high-frequency component signal in response to the center frequency being within a range of the resonance frequency; a comparing 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 the engine knocks; a determining module, configured to determine that the engine does not knock 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, comprising: An apparatus comprising a memory storing a computer program and a processor that, when executing the computer program, implements the steps of the knock detection method of any one of claims 1 to 7.

10. A computer storage medium, characterized in that, A computer storage medium having stored thereon computer-readable instructions that, when read by one or more processors, cause the one or more processors to perform the steps of the knock detection method of any one of claims 1 to 7.

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