An engine component frequency characteristic analysis method, device, equipment and medium

Abstract

This invention discloses a method, apparatus, equipment, and medium for analyzing the frequency characteristics of engine components, relating to the field of rocket engine testing technology, to solve the problems of low accuracy and time-consuming nature of existing frequency characteristic analysis methods. The method for analyzing the frequency characteristics of engine components includes: acquiring exciter parameters and pressure time-domain signals at measuring points during dynamic characteristic testing; selecting a corresponding transformation method to transform the pressure time-domain signals to obtain a three-dimensional time-frequency chromatogram based on a comparison between the sweep rate and a preset rate threshold; obliquely slicing the three-dimensional time-frequency chromatogram to obtain a target three-dimensional time-frequency chromatogram; generating amplitude-frequency curves corresponding to each measuring point based on the target three-dimensional time-frequency chromatogram; and determining the frequency characteristics of the engine component based on the amplitude-frequency curves corresponding to each measuring point. The engine component frequency characteristic analysis method provided by this invention improves the accuracy of engine component frequency characteristic analysis.

Description

Technical Field

[0001] This invention relates to the field of rocket engine testing technology, and in particular to a method, apparatus, equipment and medium for analyzing the frequency characteristics of engine components. Background Technology

[0002] Studying the frequency characteristics of rocket engine components is of great significance for engine stability analysis and understanding the health status of engine components. Currently, fluid flow tests are commonly used to study the frequency characteristics of rocket engine components. However, traditional fluid flow tests are difficult to excite the dynamic characteristics of engine components, so dynamic characteristic tests are needed. Dynamic characteristic tests require hydraulic excitation. Since the excitation source state is inconsistent in each test, it may lead to inconsistent excitation levels of the main test system each time. In order to eliminate the influence of inconsistent excitation source state, it is necessary to establish the transfer function of the test component relative to the exciter by processing the test data.

[0003] Current experimental data processing methods are usually limited to analysis in the time domain, resulting in poor data feature mining and inaccurate frequency characteristics of analyzed engine components; or the time and frequency resolution of experimental data processing using Fourier transform are insufficient, making it impossible to effectively utilize the experimental data; or manual reading of chromatograms is used, which consumes a lot of time. Summary of the Invention

[0004] The purpose of this invention is to provide a method, apparatus, equipment, and medium for analyzing the frequency characteristics of engine components, thereby improving the utilization rate of dynamic characteristic test data, increasing the accuracy of engine component frequency characteristic analysis, and saving time.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] In a first aspect, the present invention provides a method for analyzing the frequency characteristics of engine components, comprising:

[0007] The exciter parameters and pressure time-domain signals at the measuring points are obtained during the dynamic characteristic test; the measuring points include the rocket engine test assembly and the exciter; the exciter parameters include the sweep start frequency, sweep end frequency, sweep rate, and sweep time.

[0008] Based on the comparison result between the sweep rate and the preset rate threshold, the corresponding transformation method is selected to transform the pressure time domain signal to obtain a three-dimensional time-frequency chromatogram.

[0009] The target three-dimensional time-frequency chromatogram is obtained by oblique cutting of the three-dimensional time-frequency chromatogram based on the sweep time, sweep start frequency, and sweep end frequency.

[0010] Generate amplitude-frequency curves corresponding to each measurement point based on the target three-dimensional time-frequency chromatogram;

[0011] The frequency characteristics of the engine components are determined based on the amplitude-frequency curves corresponding to each measuring point.

[0012] Compared with existing technologies, the present invention provides a method for analyzing the frequency characteristics of engine components. This method acquires the exciter parameters and pressure time-domain signals at measuring points during dynamic characteristic tests. Based on the comparison between the sweep rate and a preset rate threshold, a corresponding transformation method is selected to transform the pressure time-domain signals to obtain a three-dimensional time-frequency chromatogram. This improves the time and frequency resolution of pressure time-domain signal processing. Simultaneously, analysis in the time-frequency domain fully explores the characteristics of the test data, improving the accuracy of frequency analysis. By using the sweep time, sweep start frequency, and sweep end frequency, the three-dimensional time-frequency chromatogram is obliquely truncated to obtain the target three-dimensional time-frequency chromatogram. This narrows the scope and quickly locates the target three-dimensional time-frequency chromatogram, avoiding the significant time required for manual reading. Amplitude-frequency curves corresponding to each measuring point are generated based on the target three-dimensional time-frequency chromatogram. The frequency characteristics of the engine component are determined based on the amplitude-frequency curves corresponding to each measuring point. This method effectively utilizes test data, improves the accuracy of frequency characteristic analysis, and saves time.

[0013] In a second aspect, the present invention provides an engine component frequency characteristic analysis device, comprising:

[0014] The exciter parameter and pressure time-domain signal acquisition module is used to acquire the exciter parameters and pressure time-domain signals at the measuring points in the dynamic characteristic test; the measuring points include the rocket engine test assembly and the exciter; the exciter parameters include the sweep start frequency, sweep end frequency, sweep rate and sweep time.

[0015] The three-dimensional time-frequency chromatogram determination module is used to select the corresponding transformation method to transform the pressure time-domain signal to obtain a three-dimensional time-frequency chromatogram based on the comparison result between the sweep rate and the preset rate threshold.

[0016] The oblique cutting module is used to obliquely cut the three-dimensional time-frequency chromatogram according to the sweep time, sweep start frequency and sweep end frequency to obtain the target three-dimensional time-frequency chromatogram.

[0017] The amplitude-frequency curve generation module is used to generate amplitude-frequency curves corresponding to each measurement point based on the target three-dimensional time-frequency chromatogram.

[0018] The frequency response determination module is used to determine the frequency response of engine components based on the amplitude-frequency curves corresponding to each measurement point.

[0019] Thirdly, the present invention provides an engine component frequency characteristic analysis device, comprising:

[0020] The communication unit / interface acquires the exciter parameters and pressure time-domain signals at the measuring points during dynamic characteristic tests; the measuring points include rocket engine test components and the exciter; the exciter parameters include the sweep start frequency, sweep end frequency, sweep rate, and sweep time.

[0021] The processing unit / processor is used to select the corresponding transformation method to transform the pressure time-domain signal to obtain a three-dimensional time-frequency chromatogram based on the comparison result between the sweep rate and the preset rate threshold.

[0022] The target three-dimensional time-frequency chromatogram is obtained by oblique cutting of the three-dimensional time-frequency chromatogram based on the sweep time, sweep start frequency, and sweep end frequency.

[0023] Generate amplitude-frequency curves corresponding to each measurement point based on the target three-dimensional time-frequency chromatogram;

[0024] The frequency characteristics of the engine components are determined based on the amplitude-frequency curves corresponding to each measuring point.

[0025] Fourthly, the present invention provides a computer storage medium storing instructions that, when executed, implement the above-described engine component frequency characteristic analysis method.

[0026] The technical effects achieved by the device-type solution provided in the second aspect, the equipment-type solution provided in the third aspect, and the computer storage medium solution provided in the fourth aspect are the same as those achieved by the method-type solution provided in the first aspect, and will not be repeated here. Attached Figure Description

[0027] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this invention, illustrate exemplary embodiments of the invention and are used to explain the invention, but do not constitute an undue limitation of the invention. In the drawings:

[0028] Figure 1 A flowchart of a method for analyzing the frequency characteristics of engine components provided by the present invention;

[0029] Figure 2 The three-dimensional time-frequency chromatogram obtained by short-time Fourier transform provided by this invention;

[0030] Figure 3 The target three-dimensional time-frequency chromatogram obtained after oblique cutting processing provided by the present invention;

[0031] Figure 4 This invention provides a schematic diagram of the frequency versus time curve.

[0032] Figure 5 This is a schematic diagram of the amplitude-frequency curve provided by the present invention;

[0033] Figure 6 A schematic diagram of the transfer function curves of each measuring point relative to the exciter provided by the present invention;

[0034] Figure 7 This is a schematic diagram of the structure of an engine component frequency characteristic analysis device provided by the present invention;

[0035] Figure 8 This is a schematic diagram of the structure of an engine component frequency characteristic analysis device provided by the present invention.

[0036] Figure label:

[0037] 1 - First frequency data, 2 - Second frequency data, 3 - First frequency boundary, 4 - Second frequency boundary. Detailed Implementation

[0038] To facilitate a clear description of the technical solutions in the embodiments of the present invention, the terms "first" and "second" are used to distinguish identical or similar items with essentially the same function and effect. For example, the first threshold and the second threshold are merely used to distinguish different thresholds and do not limit their order. Those skilled in the art will understand that the terms "first" and "second" do not limit the quantity or execution order, and that the terms "first" and "second" are not necessarily different.

[0039] It should be noted that in this invention, the terms "exemplary" or "for example" are used to indicate examples, illustrations, or descriptions. Any embodiment or design described as "exemplary" or "for example" in this invention should not be construed as being more preferred or advantageous than other embodiments or designs. Specifically, the use of terms such as "exemplary" or "for example" is intended to present the relevant concepts in a concrete manner.

[0040] In this invention, "at least one" refers to one or more, and "more than one" refers to two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone, where A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one of a, b, or c can represent: a, b, c, a combination of a and b, a combination of a and c, a combination of b and c, or a, b, and c, where a, b, and c can be single or multiple.

[0041] Before introducing the embodiments of the present invention, the relevant terms involved in the embodiments of the present invention are first defined as follows:

[0042] Frequency sweep refers to the process by which the frequency of a signal changes continuously from low to high or from high to low within a frequency band.

[0043] Frequency characteristics are a form of expression of a system's mathematical model. They characterize the system's motion and are considered the theoretical basis for system frequency domain analysis. For a linear time-invariant system with zero initial conditions, when the frequency of the input sinusoidal signal continuously varies from zero to infinity, the variation of the amplitude ratio and phase difference between the steady-state sinusoidal output and the sinusoidal input with the input frequency constitutes the system's frequency characteristics.

[0044] Dynamic characteristic testing of rocket engine components involves exciting the liquid flowing through the component under test using a vibrator, and then analyzing the test data to obtain the frequency characteristics of the engine component. Existing methods typically perform data analysis in the time domain, resulting in limited data feature mining, or employ methods such as short-time Fourier transform for data processing, which suffers from insufficient time and frequency resolution, leading to inaccurate frequency characteristics. Inaccurate frequency characteristic analysis will fail to accurately reflect the health status of the rocket engine components, potentially causing rocket malfunctions and other consequences.

[0045] To address the aforementioned problems, this invention provides a method, apparatus, device, and medium for analyzing the frequency characteristics of engine components. This method processes test data from dynamic characteristic tests to obtain accurate frequency characteristics of engine components. The following description is in conjunction with the accompanying drawings.

[0046] Figure 1 A flowchart of a method for analyzing the frequency characteristics of engine components provided by the present invention is shown below. Figure 1 As shown, this method includes the following steps:

[0047] Step 101: Obtain the exciter parameters and pressure time-domain signals at the measuring points in the dynamic characteristic test.

[0048] Dynamic characteristic testing involves applying excitation to the liquid flowing through the component under test using a vibrator. Measurement points include the rocket engine test component and the vibrator; multiple measurement points can be set for the rocket engine test component, such as at the front and rear of the component. Pressure sensors are placed at the measurement points to measure pressure signals. Before the test, the vibrator parameters are set according to the test requirements, including the sweep start frequency, sweep end frequency, sweep rate, and sweep time. The application of excitation by the vibrator and the acquisition of pressure signals at each measurement point are performed simultaneously, and the sweep time is the same as the acquired pressure time-domain signal and the test time.

[0049] Step 102: Based on the comparison result between the sweep rate and the preset rate threshold, select the corresponding transformation method to transform the pressure time-domain signal to obtain a three-dimensional time-frequency chromatogram. Each moment in the three-dimensional time-frequency chromatogram corresponds to multiple frequencies and amplitudes.

[0050] As an optional approach, the step of selecting a corresponding transformation method to transform the pressure time-domain signal to obtain a three-dimensional time-frequency chromatogram based on the comparison result between the sweep rate and a preset rate threshold includes:

[0051] The sweep rate corresponding to the pressure time domain signal is compared with a preset rate threshold to obtain the comparison result; the preset rate threshold can be 10Hz / s, 11Hz / s, etc.

[0052] If the sweep rate is lower than a preset threshold, the pressure time-domain signal is transformed using LMS software via short-time Fourier transform. Short-time Fourier transform divides the entire pressure time-domain signal into multiple equal-length segments by selecting a window length, and performs time-frequency transformation on each segment to process non-stationary signals. When the time-domain signal exhibits a slow-changing characteristic (slow sweep), it is considered stationary within a sufficiently long window. In this case, short-time Fourier transform naturally satisfies the high frequency resolution characteristic at that time resolution. This method is very simple and effective for processing low-sweep signals, such as pressure time-domain signals with sweep rates less than 10Hz, and can meet the required time and frequency accuracy for analysis. The resulting three-dimensional time-frequency chromatogram can be combined with… Figure 2 Please provide an explanation, such as Figure 2 As shown, the three-dimensional time-frequency chromatogram obtained by performing a short-time Fourier transform on the pressure time-domain signal includes data in three dimensions: time, frequency, and amplitude. The time range is 0–80 s, the frequency range is 0–250 Hz, and the amplitude range is 0–0.4 MPa. Short-time Fourier transforms typically include data at multiple multiples of frequency, such as… Figure 2 The data shown are 1 times the frequency and 2 times the frequency.

[0053] If the sweep rate is greater than or equal to a preset rate threshold, synchronous compressed wavelet transform is used to transform the pressure time-domain signal to obtain a three-dimensional time-frequency chromatogram. Specifically, synchronous compressed wavelet transform decomposes the signal into components at different time and frequency scales through a layer-by-layer approximation method using multiple wavelets. Based on this, a synchronous compression algorithm is used to rearrange the time-frequency coefficients, concentrating the energy distribution of the signal in the time-frequency plane to the centroid position, resulting in better convergence of time-frequency energy in both time and frequency directions. When the time-domain signal exhibits strong non-stationary processes, such as pressure time-domain signals with sweep rates greater than 10Hz, short-time Fourier transform can only ensure frequency resolution by selecting a longer time window or by sacrificing frequency resolution within a shorter time window, leading to time-frequency ambiguity. Synchronous compressed wavelet transform, through energy concentration methods, can simultaneously improve time-frequency accuracy and reduce time-frequency ambiguity.

[0054] By using short-time Fourier transform to transform the pressure time-domain signal when the sweep rate is lower than the preset rate threshold, and using synchronous compressed wavelet transform to transform the pressure time-domain signal when the sweep rate is greater than or equal to the preset rate threshold, the time resolution and frequency resolution of the data can be improved, and the experimental data can be effectively utilized.

[0055] Step 103: Based on the sweep time, sweep start frequency, and sweep end frequency, the three-dimensional time-frequency chromatogram is obliquely cut to obtain the target three-dimensional time-frequency chromatogram.

[0056] The oblique cutting of a three-dimensional time-domain chromatogram can be implemented programmatically. The purpose of oblique cutting is to accurately find the maximum amplitude and corresponding frequency at each time point. The time and frequency ranges for finding the maximum amplitude at each time point are limited. Without this operation, the maximum amplitude and corresponding frequency found may not be the desired amplitude and frequency. Specifically, this can be combined with... Figure 3 The explanation begins by determining the target time range based on the rising edge time and the sweep end time of the pressure time-domain signal. The rising edge of the time channel in the pressure time-domain signal is taken as the start time, and the sweep end time as the end time; the period from the start time to the end time constitutes the determined target time range. A three-dimensional time-frequency chromatogram is then extracted within the target time range. (See also...) Figure 2 and Figure 3 The rising edge of the pressure time domain signal corresponds to 0s, the sweep end time is 80s, and the target time range is 0 to 80s. It is important to understand that the start time in the sweep time is the time when recording the pressure time domain signal begins, and the end time is the time when recording the pressure time domain signal ends.

[0057] The three-dimensional time-frequency chromatograms within the target time range are subjected to time axis zero-point offset processing to obtain the offset three-dimensional time-frequency chromatograms; the three-dimensional time-frequency chromatograms within the target time range are offset with the rising edge of the time channel as the time axis zero point. See also Figure 2 and Figure 3 Since the rising time of the pressure time domain signal is 0s, no bias is required. If the rising time of the pressure time domain signal is not zero, the rising time needs to be zero-biased.

[0058] The frequency range is obtained by decreasing the sweep start frequency to a preset frequency threshold and increasing the sweep end frequency to a preset frequency threshold; for example... Figure 3 As shown, the first frequency boundary 3 is obtained by decreasing the starting frequency of the frequency sweep by a preset frequency threshold, and the second frequency boundary 4 is obtained by increasing the ending frequency of the frequency sweep by a preset threshold. The range consisting of line segment 3, line segment 4, time 0s, and time 80s is the maximum amplitude search interval. The data within the maximum amplitude search interval is the target three-dimensional time-frequency chromatogram to be extracted.

[0059] The three-dimensional time-frequency chromatograms within the frequency range of the biased three-dimensional time-frequency chromatogram are extracted according to the preset amplitude, thus obtaining the target three-dimensional time-frequency chromatogram corresponding to each measurement point. For example, the preset amplitude average window length can be 1 second, then the frequency and amplitude data in the three-dimensional time-frequency chromatogram are extracted every 1 second to obtain the three-dimensional time-frequency chromatogram corresponding to the time interval of 1 second. The preset amplitude average window length can be selected according to the frequency target accuracy.

[0060] Step 104: Generate the amplitude-frequency curves corresponding to each measurement point based on the target three-dimensional time-frequency chromatogram.

[0061] In a three-dimensional time-frequency chromatogram, each time point corresponds to multiple frequencies and amplitudes. The amplitude-frequency curves corresponding to each measurement point are generated based on the target three-dimensional time-frequency chromatogram. This process can be implemented through programming, and the specific steps are as follows:

[0062] Extract the frequency and amplitude data corresponding to each time point in the target's three-dimensional time-frequency chromatogram;

[0063] Determine the maximum amplitude and the corresponding frequency at each time point in the extracted data; this can be done by using a program to find the maximum value to locate the maximum amplitude and the corresponding frequency at each time point in the extracted data.

[0064] Extract the maximum amplitude and its corresponding frequency, and generate amplitude-frequency curves for each measuring point. Based on the extracted maximum amplitude and its corresponding frequency, use computer software to plot the amplitude-frequency curve for each measuring point, as shown below. Figure 5 The image shows a curve of amplitude versus time at a specific measuring point. Similarly, curves showing the frequency versus time at each measuring point can also be plotted, for example... Figure 4 The curve showing the frequency change over time at a certain measuring point is shown.

[0065] Step 105: Determine the frequency characteristics of the engine components based on the amplitude-frequency curves corresponding to each measuring point.

[0066] Specifically, the transfer function of the pressure time-domain signal at each measuring point relative to the exciter is established as follows:

[0067] Obtain the frequency and amplitude data from the amplitude-frequency curves corresponding to each measurement point of the engine test components.

[0068] Obtain the frequency and amplitude data from the exciter's amplitude-frequency curve.

[0069] The transfer function is determined by the ratio of the amplitude in the amplitude-frequency curve corresponding to the test component to the amplitude at the corresponding frequency in the amplitude-frequency curve corresponding to the exciter. For example... Figure 6The figure shows the transfer function curves of the first, second, and third measurement points relative to the exciter measurement point. The first measurement point is located downstream of the test assembly, while the second and third measurement points are located upstream of the test assembly. Based on the amplitude, phase, and frequency results of the transfer function, the frequency characteristics of the engine assembly and its attenuation effect on pressure pulsations at different frequencies are analyzed. The measurement point at the exciter serves as the excitation source.

[0070] Based on the same idea, the present invention also provides an engine component frequency characteristic analysis device. For example... Figure 7 As shown, the device may include:

[0071] The exciter parameter and pressure time-domain signal acquisition module 701 is used to acquire the exciter parameters and pressure time-domain signals at the measuring points in the dynamic characteristic test; the measuring points include the rocket engine test assembly and the exciter; the exciter parameters include the sweep start frequency, sweep end frequency, sweep rate and sweep time.

[0072] The three-dimensional time-frequency chromatogram determination module 702 is used to select the corresponding transformation method to transform the pressure time domain signal to obtain a three-dimensional time-frequency chromatogram based on the comparison result between the sweep rate and the preset rate threshold.

[0073] The oblique cutting processing module 703 is used to obliquely cut the three-dimensional time-frequency chromatogram according to the sweep time, sweep start frequency and sweep end frequency to obtain the target three-dimensional time-frequency chromatogram.

[0074] The amplitude-frequency curve generation module 704 is used to generate amplitude-frequency curves corresponding to each measurement point based on the target three-dimensional time-frequency chromatogram.

[0075] The frequency characteristic determination module 705 is used to determine the frequency characteristics of the engine components based on the amplitude-frequency curves corresponding to each measurement point.

[0076] Optionally, the three-dimensional time-frequency chromatogram determination module 702 may specifically include:

[0077] The comparison unit is used to compare the sweep rate corresponding to the pressure time-domain signal with a preset rate threshold to obtain the comparison result.

[0078] The short-time Fourier transform unit is used to transform the pressure time-domain signal using short-time Fourier transform if the frequency sweep rate is lower than a preset rate threshold, so as to obtain a three-dimensional time-frequency chromatogram.

[0079] The synchronous compressed wavelet transform unit is used to transform the pressure time-domain signal using synchronous compressed wavelet transform if the frequency sweep rate is greater than or equal to a preset rate threshold, so as to obtain a three-dimensional time-frequency chromatogram.

[0080] Optionally, the beveling module 703 can be specifically used for:

[0081] The target time range is determined based on the time corresponding to the rising edge in the pressure time domain signal and the end time of the frequency sweep.

[0082] The three-dimensional time-frequency chromatogram within the target time range is subjected to time axis zero-point offset processing to obtain the offset three-dimensional time-frequency chromatogram;

[0083] The frequency range is obtained by decreasing the sweep start frequency to a preset frequency threshold and increasing the sweep end frequency to a preset frequency threshold.

[0084] According to the preset amplitude, the three-dimensional time-frequency chromatograms located within the frequency range of the three-dimensional time-frequency chromatogram after bias processing are extracted to obtain the target three-dimensional time-frequency chromatograms corresponding to each measurement point.

[0085] Optionally, each moment in the three-dimensional time-frequency chromatogram corresponds to multiple frequencies and amplitudes; the amplitude-frequency curve generation module 704 can specifically be used for:

[0086] Extract the frequency and amplitude data corresponding to each time point in the target's three-dimensional time-frequency chromatogram;

[0087] Determine the maximum amplitude value and the frequency corresponding to the maximum amplitude value at each time point in the extracted data;

[0088] Extract the maximum amplitude and the frequency corresponding to the maximum amplitude, and generate the amplitude-frequency curve for each measurement point.

[0089] Optionally, the frequency characteristic determination module 705 can be specifically used for:

[0090] The transfer function is determined by the ratio of the amplitude in the amplitude-frequency curve corresponding to the test component to the amplitude at the corresponding frequency in the amplitude-frequency curve corresponding to the exciter, thus obtaining the frequency characteristics of the engine component.

[0091] Optionally, the synchronous compressed wavelet transform unit can be specifically used for:

[0092] The pressure time-domain signal is decomposed into components in different time and frequency dimensions;

[0093] Based on the components, the time-domain coefficients are rearranged using a synchronous compression algorithm to obtain a three-dimensional time-frequency chromatogram.

[0094] Optionally, the dynamic characteristic test applies excitation to the liquid flowing through the component under test using a vibrator.

[0095] Based on the same idea, the present invention also provides an engine component frequency characteristic analysis device. For example... Figure 8 As shown, it may include:

[0096] The communication unit / interface acquires the exciter parameters and pressure time-domain signals at the measuring points during dynamic characteristic tests; the measuring points include rocket engine test components and the exciter; the exciter parameters include the sweep start frequency, sweep end frequency, sweep rate, and sweep time.

[0097] The processing unit / processor is used to select the corresponding transformation method to transform the pressure time-domain signal to obtain a three-dimensional time-frequency chromatogram based on the comparison result between the sweep rate and the preset rate threshold.

[0098] The target three-dimensional time-frequency chromatogram is obtained by oblique cutting of the three-dimensional time-frequency chromatogram based on the sweep time, sweep start frequency, and sweep end frequency.

[0099] Generate amplitude-frequency curves corresponding to each measurement point based on the target three-dimensional time-frequency chromatogram;

[0100] The frequency characteristics of the engine components are determined based on the amplitude-frequency curves corresponding to each measuring point.

[0101] like Figure 8 As shown, the processor described above can be a general-purpose central processing unit (CPU), a microprocessor, an application-specific integrated circuit (ASIC), or one or more integrated circuits used to control the execution of the program of the present invention. The communication interface described above can be one or more. The communication interface can use any transceiver-like device for communicating with other devices or communication networks.

[0102] like Figure 8 As shown, the terminal device described above may also include a communication line. The communication line may include a path for transmitting information between the components described above.

[0103] like Figure 8As shown, the memory can be read-only memory (ROM) or other types of static storage devices capable of storing static information and instructions, random access memory (RAM) or other types of dynamic storage devices capable of storing information and instructions, or electrically erasable programmable read-only memory (EEPROM), compact disc read-only memory (CD-ROM) or other optical disc storage, optical disc storage (including compressed discs, laser discs, optical discs, digital universal optical discs, Blu-ray discs, etc.), magnetic disk storage media or other magnetic storage devices, or any other medium capable of carrying or storing desired program code in the form of instructions or data structures and accessible by a computer, but not limited to these. The memory can exist independently and be connected to the processor via communication lines. The memory can also be integrated with the processor.

[0104] In a specific implementation, as one example, such as Figure 8 As shown, a processor may include one or more CPUs, such as Figure 8 CPU0 and CPU1 in the CPU.

[0105] In a specific implementation, as one example, such as Figure 8 As shown, the terminal device may include multiple processors, such as Figure 8 The processors in the system. Each of these processors can be a single-core processor or a multi-core processor.

[0106] Based on the same idea, the present invention also provides a computer-readable storage medium storing instructions that, when executed, implement:

[0107] The exciter parameters and pressure time-domain signals at the measuring points are obtained during the dynamic characteristic test; the measuring points include the rocket engine test assembly and the exciter; the exciter parameters include the sweep start frequency, sweep end frequency, sweep rate, and sweep time.

[0108] Based on the comparison result between the sweep rate and the preset rate threshold, the corresponding transformation method is selected to transform the pressure time domain signal to obtain a three-dimensional time-frequency chromatogram.

[0109] The target three-dimensional time-frequency chromatogram is obtained by oblique cutting of the three-dimensional time-frequency chromatogram based on the sweep time, sweep start frequency, and sweep end frequency.

[0110] Generate amplitude-frequency curves corresponding to each measurement point based on the target three-dimensional time-frequency chromatogram;

[0111] The frequency characteristics of the engine components are determined based on the amplitude-frequency curves corresponding to each measuring point.

[0112] The above mainly describes the solutions provided by the embodiments of the present invention from the perspective of the interaction between various modules. It is understood that, in order to achieve the above functions, it includes corresponding hardware structures and / or software modules for executing each function. Those skilled in the art should readily recognize that, in conjunction with the units and algorithm steps of the various examples described in the embodiments disclosed herein, the present invention can be implemented in hardware or a combination of hardware and computer software. Whether a function is executed in hardware or by computer software driving hardware depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of the present invention.

[0113] The embodiments of the present invention can divide functional modules according to the above method examples. For example, each function can be divided into its own functional module, or two or more functions can be integrated into one processing module. The integrated module can be implemented in hardware or as a software functional module. It should be noted that the module division in the embodiments of the present invention is illustrative and only represents one logical functional division; other division methods may be used in actual implementation.

[0114] Optionally, the computer execution instructions in this invention may also be referred to as application code, and this invention does not specifically limit them.

[0115] The methods disclosed in this invention can be applied to or implemented by a processor. The processor may be an integrated circuit chip with signal processing capabilities. During implementation, each step of the above methods can be completed by integrated logic circuits in the processor's hardware or by instructions in software form. The processor can be a general-purpose processor, a digital signal processor (DSP), an ASIC, a field-programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components. It can implement or execute the methods, steps, and logic block diagrams disclosed in the embodiments of this invention. The general-purpose processor can be a microprocessor or any conventional processor. The steps of the methods disclosed in the embodiments of this invention can be directly implemented by a hardware decoding processor, or by a combination of hardware and software modules in the decoding processor. The software modules can reside in random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, registers, or other mature storage media in the art. This storage medium is located in memory; the processor reads information from the memory and, in conjunction with its hardware, completes the steps of the above methods.

[0116] In the above embodiments, implementation can be achieved entirely or partially through software, hardware, firmware, or any combination thereof. When implemented using software, it can be implemented entirely or partially in the form of a computer program product. The computer program product includes one or more computer programs or instructions. When the computer program or instructions are loaded and executed on a computer, the processes or functions described in the embodiments of the present invention are performed entirely or partially. The computer can be a general-purpose computer, a special-purpose computer, a computer network, a terminal, a user equipment, or other programmable device. The computer program or instructions can be stored in a computer-readable storage medium or transferred from one computer-readable storage medium to another. For example, the computer program or instructions can be transferred from one website, computer, server, or data center to another website, computer, server, or data center via wired or wireless means. The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or data center that integrates one or more available media. The available medium can be a magnetic medium, such as a floppy disk, hard disk, or magnetic tape; it can also be an optical medium, such as a digital video disc (DVD); or it can be a semiconductor medium, such as a solid-state drive (SSD).

[0117] Although the invention has been described herein in conjunction with various embodiments, those skilled in the art will understand and implement other variations of the disclosed embodiments by reviewing the accompanying drawings, the disclosure, and the appended claims in carrying out the claimed invention. In the claims, the word "comprising" does not exclude other components or steps, and "a" or "an" does not exclude a plurality. A single processor or other unit can implement several functions listed in the claims. While different dependent claims may recite certain measures, this does not mean that these measures cannot be combined to produce good results.

[0118] Although the invention has been described in conjunction with specific features and embodiments, it is obvious that various modifications and combinations can be made therein without departing from the spirit and scope of the invention. Accordingly, this specification and drawings are merely exemplary descriptions of the invention as defined by the appended claims, and are considered to cover any and all modifications, variations, combinations, or equivalents within the scope of the invention. Clearly, those skilled in the art can make various alterations and modifications to the invention without departing from its spirit and scope. Thus, if such modifications and modifications of the invention fall within the scope of the claims and their equivalents, the invention is also intended to include such modifications and modifications.

Claims

1. A method for analyzing the frequency characteristics of engine components, characterized in that, include: Acquire exciter parameters and pressure time-domain signals at measuring points during dynamic characteristic tests; measuring points include rocket engine test components and exciter. The exciter parameters include the sweep start frequency, sweep end frequency, sweep rate, and sweep time. Based on the comparison result between the sweep rate and the preset rate threshold, the corresponding transformation method is selected to transform the pressure time domain signal to obtain a three-dimensional time-frequency chromatogram. Based on the sweep time, the sweep start frequency, and the sweep end frequency, the three-dimensional time-frequency chromatogram is obliquely cut to obtain the target three-dimensional time-frequency chromatogram. Generate amplitude-frequency curves corresponding to each measurement point based on the target three-dimensional time-frequency chromatogram; The frequency characteristics of the engine components are determined based on the amplitude-frequency curves corresponding to each measurement point. The step of selecting a corresponding transformation method to transform the pressure time-domain signal to obtain a three-dimensional time-frequency chromatogram based on the comparison result between the sweep rate and the preset rate threshold includes: The sweep rate corresponding to the pressure time-domain signal is compared with a preset rate threshold to obtain the comparison result; If the frequency sweep rate is lower than the preset rate threshold, the pressure time domain signal is transformed by short-time Fourier transform to obtain a three-dimensional time-frequency chromatogram. If the frequency sweep rate is greater than or equal to the preset rate threshold, synchronous compressed wavelet transform is used to transform the pressure time domain signal to obtain a three-dimensional time-frequency chromatogram. The step of obliquely cutting the three-dimensional time-frequency chromatogram according to the sweep time, the sweep start frequency, and the sweep end frequency to obtain the target three-dimensional time-frequency chromatogram includes: The target time range is determined based on the time corresponding to the rising edge in the pressure time domain signal and the end time of the frequency sweep. The three-dimensional time-frequency chromatogram within the target time range is subjected to time axis zero-point offset processing to obtain the offset three-dimensional time-frequency chromatogram; The frequency range is obtained by decreasing the sweep start frequency to a preset frequency threshold and increasing the sweep end frequency to a preset frequency threshold. According to the preset amplitude, extract the three-dimensional time-frequency chromatograms located within the frequency range of the three-dimensional time-frequency chromatogram after bias processing, and obtain the target three-dimensional time-frequency chromatograms corresponding to each measurement point; The three-dimensional time-frequency chromatogram corresponds to multiple frequencies and amplitudes at each moment; the generation of amplitude-frequency curves corresponding to each measurement point based on the target three-dimensional time-frequency chromatogram includes: Extract the frequency and amplitude data corresponding to each time point in the target's three-dimensional time-frequency chromatogram; Determine the maximum amplitude value and the frequency corresponding to the maximum amplitude value at each time point in the extracted data; Extract the maximum amplitude and the frequency corresponding to the maximum amplitude, and generate the amplitude-frequency curve for each measurement point.

2. The method for analyzing the frequency characteristics of engine components according to claim 1, characterized in that, The step of determining the frequency characteristics of the engine components based on the amplitude-frequency curves corresponding to each measuring point includes: The transfer function is determined by the ratio of the amplitude in the amplitude-frequency curve corresponding to the test component to the amplitude at the corresponding frequency in the amplitude-frequency curve corresponding to the exciter, thus obtaining the frequency characteristics of the engine component.

3. The method for analyzing the frequency characteristics of engine components according to claim 1, characterized in that, If the frequency sweep rate is greater than or equal to a preset rate threshold, then synchronous compressed wavelet transform is used to transform the pressure time-domain signal to obtain a three-dimensional time-frequency chromatogram, including: The pressure time-domain signal is decomposed into components in different time and frequency dimensions; Based on the components, the time-domain coefficients are rearranged using a synchronous compression algorithm to obtain a three-dimensional time-frequency chromatogram.

4. The method for analyzing the frequency characteristics of engine components according to claim 1, characterized in that, The dynamic characteristic test applies excitation to the liquid flowing through the component under test using a vibrator.

5. A device for analyzing the frequency characteristics of engine components, characterized in that, The method for analyzing the frequency characteristics of an engine component as described in any one of claims 1-4 includes: The exciter parameter and pressure time-domain signal acquisition module is used to acquire the exciter parameters and pressure time-domain signals at the measuring points in the dynamic characteristic test; the measuring points include the rocket engine test assembly and the exciter; the exciter parameters include the sweep start frequency, sweep end frequency, sweep rate and sweep time. The three-dimensional time-frequency chromatogram determination module is used to select a corresponding transformation method to transform the pressure time-domain signal to obtain a three-dimensional time-frequency chromatogram based on the comparison result between the sweep rate and the preset rate threshold. The oblique cutting module is used to obliquely cut the three-dimensional time-frequency chromatogram according to the sweep time, the sweep start frequency and the sweep end frequency to obtain the target three-dimensional time-frequency chromatogram. The amplitude-frequency curve generation module is used to generate amplitude-frequency curves corresponding to each measurement point based on the target three-dimensional time-frequency chromatogram. The frequency characteristic determination module is used to determine the frequency characteristics of the engine components based on the amplitude-frequency curves corresponding to each measurement point.

6. An engine component frequency characteristic analysis device, characterized in that, The method for analyzing the frequency characteristics of an engine component as described in any one of claims 1-4 includes: A communication unit / interface is used to acquire exciter parameters and pressure time-domain signals at measurement points during dynamic characteristic tests; the measurement points include rocket engine test components and exciters; the exciter parameters include sweep start frequency, sweep end frequency, sweep rate, and sweep time. The processing unit / processor is used to select a corresponding transformation method to transform the pressure time-domain signal to obtain a three-dimensional time-frequency chromatogram based on the comparison result between the sweep rate and the preset rate threshold. Based on the sweep time, the sweep start frequency, and the sweep end frequency, the three-dimensional time-frequency chromatogram is obliquely cut to obtain the target three-dimensional time-frequency chromatogram. Generate amplitude-frequency curves corresponding to each measurement point based on the target three-dimensional time-frequency chromatogram; The frequency characteristics of the engine components are determined based on the amplitude-frequency curves corresponding to each measurement point.

7. A computer storage medium, characterized in that, The computer storage medium stores instructions that, when executed, implement the engine component frequency characteristic analysis method according to any one of claims 1 to 4.

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