Reliability checking method for signal acquisition channel in rapid change measurement system based on LMS acquisition equipment

Abstract

The invention relates to a reliability inspection method for electrical equipment, in particular to a reliability inspection method for a connector in a rapid change measurement system based on LMS acquisition equipment, and aims to solve the problems that the existing method for manually inspecting the reliability of the connector wastes time and labor, is large in workload and is easy to damage the connector. The method comprises the following steps: 1, preparing and starting a first digital signal generator and a second digital signal generator; 2, connecting the input end of the first lead with the output end of a first digital signal generator; 3, starting and initializing acquisition software in the upper computer; 4, sorting the first signal and the second signal acquired by the LMS acquisition equipment in the step 3; 5, the data processing software processes and analyzes the data to obtain feature information of the first signal and the second signal; and 6, comparing the feature information of the first signal with the feature information of the second signal to judge whether the deviation of the feature information of the first signal and the second signal is within a preset reasonable range.

Description

Technical Field

[0001] The invention relates to a reliability inspection method for electrical equipment, and in particular to a reliability inspection method for a signal acquisition path in a fast-changing measurement system based on an LMS acquisition device. Background Art

[0002] The measurement diagram of the existing fast-changing measurement system based on LMS acquisition equipment is shown in Figure 1 . The connector is an indispensable adapter component in the measurement system, but the frequent plugging and unplugging during long-term use can easily reduce the reliability of the connector. The reduced reliability mainly includes the following reasons: 1) After the connection ball-type plug is plugged and unplugged many times, the gap between the pin and the hole becomes larger, which can easily cause poor contact and the plug or socket to fall off; 2) Due to the long-term use of the adapter cabinet, the working environment of the test bench is harsh, such as strong speed change, strong corrosion or strong oxidation environment, and dry powder is occasionally used for firefighting, which can easily reduce the insulation of the measurement system; 3) The adapter cabinet, lines and connectors have a long service life, and there are factors such as line aging and reduced reliability; 4) Occasionally, cold solder joints will be formed when welding sensors or plugs, which will bury safety hazards in the measurement.

[0003] The existing reliability inspection method of connectors is usually manual inspection, which mainly includes opening the plug and observing whether the pins and solder joints are oxidized and damaged. This method is time-consuming and labor-intensive, and has a large workload. In addition, the connectors are frequently opened and then wrapped, which can easily cause slight damage to the solder pins and leads of the connectors. In the long run, the reliability of the connectors can be easily reduced. Summary of the invention

[0004] The purpose of the present invention is to solve the problems of the existing manual method of checking the reliability of connectors, which is time-consuming, labor-intensive, and easy to damage the connectors, and to provide a reliability inspection method for the signal acquisition path in a fast-changing measurement system based on an LMS acquisition device.

[0005] To achieve the above purpose, the technical solution provided by the present invention is:

[0006] A reliability inspection method for a signal acquisition path in a fast-changing measurement system based on an LMS acquisition device, the fast-changing measurement system based on the LMS acquisition device comprises an adapter, a front-end adapter cabinet, an LMS acquisition device and a host computer, the input end of the adapter is connected to a rocket engine through a first lead, the output end of the adapter is connected to the input end of the front-end adapter cabinet through an active cable, the output end of the front-end adapter cabinet is connected to the first input end of the LMS acquisition device through a long-distance main cable, and the LMS acquisition device is connected to the host computer through a network cable; the signal acquisition path comprises a first lead, an adapter, an active cable, an adapter cabinet and a long-distance main cable; both ends of the first lead, the active cable and the long-distance main cable are provided with connectors; the special feature is that the method comprises the following steps:

[0007] Step 1, prepare and start the first digital signal generator and the second digital signal generator, so that the first digital signal generator and the second digital signal generator generate the same detection waveform signal, which are the first signal and the second signal respectively, and wait until the first signal and the second signal are both stable;

[0008] Step 2, remove the first lead from the device under test, and connect it to the output end of the first digital signal generator, and connect the output end of the second digital signal generator to the second input end of the LMS acquisition device through the second lead;

[0009] Step 3: Sending instructions through the host computer to enable the LMS acquisition device to start collecting the first signal and the second signal. When the first preset condition is met, the LMS acquisition device completes and stops collecting;

[0010] Step 4, sending the first signal and the second signal collected by the LMS acquisition device in step 3 to the host computer, generating result data after processing, and collating the result data;

[0011] Step 5: The host computer processes and analyzes the result data to obtain characteristic information of the first signal and the second signal;

[0012] Step 6, compare the characteristic information of the first signal and the second signal, and set a preset reasonable range; if the deviation of the characteristic information of the first signal and the second signal is within the preset reasonable range, it is determined that the connections of all connectors in the rapid change measurement system based on the LMS acquisition device are reliable, and the reliability check is completed; if the deviation of the characteristic information of the first signal and the second signal is not within the preset reasonable range, change the connection position of the first digital signal generator in the signal acquisition path and repeat steps 3 to 5 to determine the fault location.

[0013] Furthermore, in step 1, the detection waveform is a sine function with a frequency of f=10kHz, an amplitude of A=5V, and an initial phase

[0014] Furthermore, the first preset condition in step 3 is specifically: reaching a preset acquisition time t or a preset number of sampling points N, t ≥ 300s, N ≥ 6×10 5 .

[0015] Furthermore, the result data described in step 4 is stored in *.txt format; and “arranging the result data” specifically converts the result data from *.txt format to *.unv format.

[0016] Furthermore, the characteristic information in step 5 includes spectrum shape, peak position and amplitude.

[0017] Furthermore, in step 6, the preset reasonable range is specifically: the spectrum shape similarity of the two signals is ≥80%, the peak phase value deviation percentage is ≤5%, and the amplitude deviation percentage is ≤10%.

[0018] Furthermore, in step 6, the connection position of the first digital signal generator is changed and steps 3 to 5 are repeated to determine the fault position specifically:

[0019] α) Remove the first lead from the output end of the first digital signal generator, remove the active cable from the output end of the adapter and connect it to the output end of the first digital signal generator, perform steps 3 to 5 in sequence, and compare the characteristic information of the first signal and the second signal. If the deviation of the characteristic information of the first signal and the second signal is within a preset reasonable range, it is determined that the fault is located on the first lead or the adapter, and step β1) is performed; if the deviation of the characteristic information of the first signal and the second signal is not within the preset reasonable range, step β2) is performed;

[0020] β1) Replace a new first lead, then connect the output end of the first digital signal generator to the input end of the first lead, and perform steps 3 to 5 in sequence to compare the characteristic information of the first signal and the second signal; if the deviation of the characteristic information of the first signal and the second signal is within a preset reasonable range, it is determined that the fault is located on the first lead; if the deviation of the characteristic information of the first signal and the second signal is not within the preset reasonable range, it is determined that the fault is located on the adapter; the reliability check is completed;

[0021] β2) Replace a new active cable, and then connect the active cable to the output end of the first digital signal generator, and perform steps 3 to 5 in sequence to compare the characteristic information of the first signal and the second signal; if the deviation of the characteristic information of the first signal and the second signal is within a preset reasonable range, it is determined that the fault is located on the active cable, and the reliability check is completed; if the deviation of the characteristic information of the first signal and the second signal is not within the preset reasonable range, perform step γ);

[0022] γ) Remove the long-distance main cable from the output end of the front switching cabinet and connect it to the output end of the first digital signal generator. After performing steps 3 to 5 in sequence, compare the characteristic information of the first signal and the second signal; if the deviation of the characteristic information of the first signal and the second signal is within the preset reasonable range, it is determined that the fault is located in the front switching cabinet; if the deviation of the characteristic information of the first signal and the second signal is not within the preset reasonable range, it is determined that the fault is located in the long-distance main cable; complete the reliability check.

[0023] Furthermore, step 5 is specifically as follows:

[0024] Step 5.1, dividing the first signal and the second signal into equal time periods;

[0025] Step 5.2, analyzing the first signal and the second signal in each time period in the navigator module of the LMS data processing software, respectively, to obtain an average spectrum diagram, a chromatogram, and a slice diagram of the first signal and the second signal;

[0026] Step 5.3: Utilize the obtained average spectrum diagram, chromatogram and slice diagram to obtain the spectrum shape, peak position and amplitude data of the first signal and the second signal.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] 1. The reliability inspection method of the signal acquisition path in the fast-changing measurement system based on the LMS acquisition device provided by the present invention uses the characteristic information of the first signal and the second signal to judge the reliability of the signal acquisition path, avoiding the complex and time-consuming operations of opening the plug to observe the pins and solder joints in the traditional method; the traditional method requires manual opening of the connector one by one, and carefully checking the condition of each pin and solder joint, which is not only a huge workload, but also easily affected by human factors, such as the eyesight and experience of the inspector; while the present invention only needs to generate a specific signal through two programmable digital signal generators, and the LMS acquisition system collects and analyzes the spectrum, and then compares the spectrum map characteristics. The operation process is relatively concise and clear, and it is easy for technicians to master and implement; in the entire detection process, from the setting of the digital signal generator, the signal output connection to the acquisition channel configuration, signal acquisition and processing, etc., there are clear operating specifications and processes. For example, in the digital signal generator startup and waveform generation steps, it is only necessary to program the setting to generate a specific waveform according to the characteristics of the fast-changing measurement system and the detection requirements of the signal acquisition path, without the need for complex detection tools and additional manual judgment, which greatly reduces the difficulty of operation and improves the detection efficiency.

[0029] 2. The reliability inspection method of the signal acquisition path in the fast-changing measurement system based on the LMS acquisition device provided by the present invention, from a theoretical basis, the connector and the cable can be equivalent to a mathematical model composed of resistance and capacitance, and the changes in line capacitance and resistance will affect the line frequency component; when there is a problem with the connector, the signal spectrum will change significantly, such as disorderly sudden frequency changes and increased sudden frequency components; the present invention is based on this theory and judges the reliability of the connector by analyzing the characteristics of the spectrum graph. It has a solid theoretical basis and is more scientific than the traditional method that only relies on appearance inspection.

[0030] 3. The reliability inspection method of the signal acquisition path in the fast-changing measurement system based on the LMS acquisition device provided by the present invention. In practice, the present invention can quantitatively select a more reliable measurement channel by designing a waveform with multi-band characteristics through self-compiled algorithms, comparing and analyzing line spectrum data and channel correlation; for example, in the data processing process, multi-dimensional analysis is performed on the data collected in different time periods, including time domain amplitude range, deviation, drift measurement and spectrum analysis, etc., comprehensively considering multiple factors, avoiding the limitation of single factor judgment, so as to more accurately determine whether the connector has abnormality, effectively improve the reliability of the detection result, and provide a strong guarantee for the stable operation of the fast-changing measurement system. The method further ensures the accuracy of the judgment by comparing with the spectrum analysis result directly added to the input end of the LMS acquisition device by the signal generator, making the detection result more credible; through this comparison, the interference of other factors in the signal transmission process can be eliminated, and the reliability of the connector itself can be accurately judged. Without this comparison, the problem in the signal transmission line may be misjudged as a connector problem, or vice versa, thereby affecting the accurate diagnosis and repair of system faults.

[0031] 4. The reliability inspection method of the signal acquisition path in the fast-changing measurement system based on the LMS acquisition device provided by the present invention can accurately detect the reliability of the connector, which helps to timely discover potential problems and avoid abnormal measurement data or system shutdown caused by connector failure. In fields such as aerospace that have extremely high reliability requirements, the stable operation of the fast-changing measurement system is crucial, and any minor failure may cause serious consequences. This patented technology can effectively improve the accuracy and reliability of connector detection, thereby ensuring the stable operation of the entire fast-changing measurement system, ensuring the accuracy and reliability of test data, and providing solid data support for the research and development and testing of equipment such as aerospace engines. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a measurement schematic diagram of the existing fast-changing measurement system based on LMS acquisition equipment;

[0033] Figure 2 It is a flow chart of an embodiment of the present invention, wherein the orange box is a signal acquisition path;

[0034] Figure 3 The equivalent schematic diagram of the measuring cable in the circuit;

[0035] Description of reference numerals:

[0036] 1-first digital signal generator; 2-first lead; 3-adapter; 4-active cable; 5-adapter cabinet; 6-long-distance main cable; 7-second digital signal generator; 8-second lead; 9-LMS acquisition equipment; 10-network cable; 11-host computer; 12-rocket engine; 121-vibration sensor; 122-vibration measuring block. DETAILED DESCRIPTION

[0037] like Figure 1 The figure shows the measurement schematic diagram of the existing fast-changing measurement system based on the LMS acquisition device. From the perspective of the entire measurement system, any abnormal measurement link will inevitably lead to abnormal measurement data. For the singular signal data in the data, the commonly used analysis method is to use the traditional extreme value analysis method, that is, to judge whether the measured data is a singular point by whether the absolute value of the measured data subtracted from a given value is within a given range. This is because the irregular parts such as the mutation part and the singular point in the signal usually contain important information. The singularity of the signal has two meanings: (1) The amplitude of the signal changes suddenly at a certain moment, causing the discontinuity of the signal; (2) The signal looks very smooth, and the amplitude does not suddenly change, but the first-order differential of the signal has a sudden change and the first-order differential is discontinuous. For fast-changing signals with fast signal changes and wide signal bandwidth, the commonly used analysis method is to perform Fourier analysis on a certain time interval, and judge whether it is abnormal by the speed of attenuation of the spectrum or the number of sudden frequency components, and judge whether the signal has singularity in this interval.

[0038] One of the criteria for determining the cause of data anomalies is to use the correlation analysis method to analyze and compare the remaining parameter data related to the parameter in this test in combination with the entire test process, so as to determine the cause of the data anomaly. Another method of determination is to compare and analyze the test data of the same model in the past to draw an analytical conclusion on the cause of the signal anomaly. Theoretically, no matter what the cause of the signal anomaly is, in essence, the mathematical mechanism model of the signal anomaly has great similarities. There are four main modes of data signal anomalies, including signal deviation anomaly, signal drift problem, signal accuracy level reduction, and signal complete failure. Deviation anomaly mainly refers to a type of failure in which the abnormal measurement value differs from the correct measurement value by a certain constant.

[0039] Right now:

[0040] x e =k (1)

[0041] Where k is a constant.

[0042] The drift problem refers to a type of fault in which the fault size changes linearly over time, and its representation is:

[0043] x e =h(tt f ) (2)

[0044] Among them, t f is the starting time of the fault; t is any time after the fault occurs; h is a constant.

[0045] This type of fault is manifested in that the fault measurement value continues to increase over time.

[0046] Deviation and drift faults are manifested in the deviation of the measured average value. When the accuracy level is reduced, the measured average value does not change, but the measured variance changes. The specific expression is:

[0047]

[0048] In the formula To measure the change in variance, N represents a normal distribution.

[0049] because According to the knowledge of probability theory, the sum of two normal distributions is still a normal distribution, so we have:

[0050]

[0051] It can be seen from the formula that this type of fault is similar to free noise, similar to the increase in variance of free noise, which will cause the faulty measurements to be mixed with the fault-free measurements.

[0052] In the case of a complete failure, the measured value does not change with the actual change and always maintains a certain reading. Usually this constant value is usually zero or the maximum reading. This type of failure can be expressed as:

[0053] x t =c (5)

[0054] Among them, x e is a drift fault, x z is the variable associated with the change in measurement variance, x t is the variable after considering drift fault and measurement variance change, x f is the faulty measurement value. The above variables are mainly used to describe the faulty measurement value and its related statistical characteristics, especially when considering drift faults and changes in measurement variance.

[0055] The above model only analyzes the fast-changing fault signal from the perspective of time domain, but the fast-changing signal itself is a random signal. It is unscientific to analyze it only from the perspective of time domain. Therefore, it is necessary to conduct an in-depth analysis of the fault signal from the perspective of frequency domain. Theoretically, when the connector of the fast-changing measurement system is in good condition, the spectrum of its measurement data has certain significant characteristics. When there is a problem with the connector of the measurement system, its signal spectrum will also change significantly. Therefore, measuring and analyzing the time domain and frequency domain changes of the fast-changing signal is the basis of connector diagnosis. Time domain analysis is to study the law of the change of the signal shape over time, and extract the necessary characteristic quantities (such as amplitude, period, local rise time and fall time, etc.) as the basis for signal judgment and identification. Frequency domain analysis is to study the law of the change of the signal energy or power over time, so as to provide a basis and means for further processing of the signal. The frequency domain analysis of the signal is more intuitive and convenient than the time domain waveform analysis. In order to identify the connector fault signal, it is usually necessary to properly process the signal recorded on site, and identify the fault signal in the processing result to determine the fault location and fault degree.

[0056] In view of the currently used LMS acquisition system, it provides the following convenient conditions for the connector fault diagnosis solution:

[0057] ⑴ Since the LMS acquisition system itself integrates a charge amplifier, the front and back channels of the existing rapid measurement system can correspond one to one. This replaces the original discrete charge amplifier that is frequently replaced, resulting in inconsistent channel states each time and inability to compare the consistency of the measured data;

[0058] ⑵The LMS acquisition system records all rapidly changing parameters without any additional instruments, which minimizes the impact of uncertainty in the measurement state of the rapidly changing measurement system and facilitates multiple comparisons of measurement signals.

[0059] In order to improve the overall reliability of the rapid change measurement system, and in combination with the needs of digital measurement, the following connector reliability scheme is proposed: First, a programmable digital signal generator is used to generate a waveform of a specific typical signal and add it to the cable input end, and then the LMS acquisition system is used to acquire the signal and perform spectrum and channel correlation analysis. Then, the spectrum result is compared with the result of the spectrum analysis of the signal generated by the signal generator directly added to the input end of the LMS acquisition system to find out the common features and differences of the graphics in the two spectrum diagrams, and then determine whether the channel cable connector is connected reliably. The principle diagram of the measurement scheme is as follows Figure 2 shown.

[0060] There are two main theoretical principles for implementing this solution: First, in theory, both connectors and cables can be equivalent to mathematical models composed of resistors and capacitors. In practice, most connectors are round cable plugs, and the calculation formula for the differential capacitance C between the two pins on the connector is:

[0061]

[0062] Among them, ε is the dielectric constant of the dielectric material between the two pins; S is the distance between the two pins (mm); d is the pin diameter (mm); and D is the diameter of the circular connector (mm).

[0063] The measuring cable can be equivalent to a low-pass filter in the circuit. Its equivalent schematic diagram is as follows: Figure 3 As shown, the upper limit medium frequency f of the filter c for:

[0064] f c =1 / πRC (7)

[0065] Where R is the resistance of the circuit, in Ω; C is the differential capacitance between the two pins, in F.

[0066] From this, it can be seen that the inspection of the reliability of the docking plugs and cables is closely related to the line capacitance and resistance. Changes in the capacitance and resistance of the entire line will affect changes in the line frequency components. Second, from the experience of data analysis, a reliable and secure connection will reflect fixed frequency change characteristics on the spectrum graph. An obvious feature of the spectrum of an unreliable connection is that the sudden frequency changes in the spectrum graph are disorderly and the sudden frequency components increase.

[0067] The method to implement this solution is: design a waveform with low-frequency, medium-frequency and high-frequency characteristics through a self-compiled algorithm, and then send it to two signal generators by a computer, compare and analyze the previous spectrum data of the line, and perform channel correlation analysis to determine the reliability of the line. This solution can not only quantitatively select which measurement channels are more reliable, but also make this detection method more scientific and reasonable than the direct measurement of line insulation and resistance. At the same time, this method automatically realizes circuit reliability inspection on a computer through only a programmable signal generator, and the implementation method is simple and efficient.

[0068] Both theory and practice show that the high-frequency component of a signal plays an extremely important role in predicting the occurrence of a fault, while the low-frequency part indicates the fault mode when the fault occurs. Therefore, the feature extraction of the measured rapidly changing signal is often based on the frequency domain. Rapidly changing characteristic data refers to the relevant data extracted from the rapidly changing time domain signal through relevant signal processing methods such as FFT, including the total vibration value of the rapidly changing signal, the amplitude of the main frequency and its various multiples, and the residual amount. The total vibration value refers to the maximum value of the rapidly changing time domain signal curve. The amplitude of each multiple is converted into a frequency domain signal, i.e., a spectrum, by FFT transformation or other signal processing algorithms. Then, the amplitude at the specific frequency point of interest is extracted from the spectrum of the rapidly changing signal. The residual amount refers to the remaining part after subtracting the amplitude of each multiple that has been extracted from the total extreme value of the rapidly changing signal, which is used to reflect the magnitude of the rapidly changing energy at other frequencies except for each characteristic frequency.

[0069] For the signal of rapid change measurement, it includes two aspects: one is the noise monitoring of the rapid change measurement system several days before each test. After a period of monitoring of the noise of the rapid change measurement system, it is found that the noise is generally decreasing from morning to afternoon, and the 50Hz interference in the noise is more obvious. The monitoring of the same channel shows that the distribution of 50Hz, 150Hz, and 250Hz power frequency interference in the spectrum does not change too obviously in different time periods, and its pattern has a certain fixedness, but the distribution of other frequencies will be closely related to the insulation of cables and connectors. For this reason, the total extreme value can be used to record the energy of each channel, and the 50Hz, 150Hz, and 250Hz power frequency interference are counted as the main frequency of each channel, and the remaining frequencies are counted as residual quantities. Second, each rapid change measurement system applies frequency signals of different frequency bands, and the measured data is measured for the time domain amplitude range, deviation, and drift. At the same time, the corresponding spectrum analysis is performed on each channel to determine the statistical characteristics of the total extreme value, main frequency, and residual quantity of each channel. Then, through multiple horizontal and vertical comparisons of these statistical quantities, it is determined whether there is an abnormality in the channel connector. At the same time, this method can also screen out the most stable channel and the performance stability of each channel.

[0070] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0071] A reliability inspection method for connectors in a fast-changing measurement system based on an LMS acquisition device, see Figure 1The fast-changing measurement system based on the LMS acquisition device includes an adapter 3, a front-end adapter cabinet 5, an LMS acquisition device 9 and a host computer 11. The input end of the adapter 3 is connected to the vibration sensor 121 of the vibration measuring block 122 on the rocket engine 12 through the first lead 2, and the output end of the adapter 3 is connected to the input end of the front-end adapter cabinet 5 through the active cable 4. The output end of the front-end adapter cabinet 5 is connected to the first input end of the LMS acquisition device 9 through the long-distance main cable 6. The LMS acquisition device 9 is connected to the host computer 11 through the network cable 10; the signal acquisition path includes the first lead 2, the adapter 3, the active cable 4, the adapter cabinet 5 and the long-distance main cable 6; both ends of the first lead 2, the active cable 4 and the long-distance main cable 6 are provided with connectors;

[0072] See also Figure 2 , the steps of this embodiment are as follows:

[0073] Step 1, prepare the first digital signal generator 1 and the second digital signal generator 7 and start them, so that the first digital signal generator 1 and the second digital signal generator 7 generate the same detection waveform signal, which are the first signal and the second signal respectively, and wait until the first signal and the second signal are both stable; wherein the detection waveform is a sine function with a frequency of f=10kHz, an amplitude of A=5V, and an initial phase

[0074] Step 2, remove the first lead 2 from the rocket engine 12, and connect it to the output end of the first digital signal generator 1, and connect the output end of the second digital signal generator 7 to the second input end of the LMS acquisition device 9 through the second lead 8; usually, the first lead 2 is connected to the vibration sensor 121 of the vibration measuring block 122 on the rocket engine 12, so it needs to be removed;

[0075] Step 3: Send an instruction through the host computer 11 to enable the LMS acquisition device 9 to start collecting the first signal and the second signal. When the preset acquisition time t≥300s or the preset number of sampling points N≥6×10 5 When the LMS acquisition device 9 completes and stops the acquisition; the LMS acquisition device 9 completes and stops the acquisition;

[0076] Step 4, sorting the first signal and the second signal collected by the LMS acquisition device 9 in step 3 to generate result data in *.txt format; converting the result data from *.txt format to *.unv format and importing it into the data processing software; and storing the result data;

[0077] Step 5: Data processing software processes and analyzes the data to obtain characteristic information of the first signal and the second signal;

[0078] Step 5.1, dividing the first signal and the second signal into equal time periods;

[0079] Step 5.2, analyzing the first signal and the second signal in each time period in the navigator module of the LMS data processing software, respectively, to obtain an average spectrum diagram, a chromatogram, and a slice diagram of the first signal and the second signal;

[0080] Step 5.3, using the obtained average spectrum diagram, chromatogram and slice diagram, obtain the spectrum shape, peak position and amplitude data of the first signal and the second signal;

[0081] Step 6: Compare the characteristic information of the first signal and the second signal, and set a preset reasonable range; if the deviation of the characteristic information of the first signal and the second signal is within the preset reasonable range, it is determined that the connection of all connectors in the rapid change measurement system based on the LMS acquisition device is reliable, and the reliability check is completed; if the deviation of the characteristic information of the first signal and the second signal is not within the preset reasonable range, execute:

[0082] Compare the characteristic information of the first signal and the second signal, and set a preset reasonable range; if the deviation of the characteristic information of the first signal and the second signal is within the preset reasonable range, it is determined that the connections of all connectors in the rapid change measurement system based on the LMS acquisition device are reliable, and the reliability check is completed; if the deviation of the characteristic information of the first signal and the second signal is not within the preset reasonable range.

Claims

1. A reliability inspection method for a signal acquisition path in a fast-changing measurement system based on an LMS acquisition device, the fast-changing measurement system based on the LMS acquisition device comprising an adapter (3), a front switching cabinet (5), an LMS acquisition device (9) and a host computer (11), the input end of the adapter (3) being connected to a rocket engine (12) via a first lead (2), the output end of the adapter (3) being connected to the input end of the front switching cabinet (5) via an active cable (4), the output end of the front switching cabinet (5) being connected to the first input end of the LMS acquisition device (9) via a long-distance main cable (6), the LMS acquisition device (9) being connected to the host computer (11) via a network cable (10); the signal acquisition path comprising a first lead (2), an adapter (3), an active cable (4), a switching cabinet (5) and a long-distance main cable (6); both ends of the first lead (2), the active cable (4) and the long-distance main cable (6) are provided with connectors; it is characterized in that The following steps are involved: Step 1, preparing a first digital signal generator (1) and a second digital signal generator (7) and starting them, so that the first digital signal generator (1) and the second digital signal generator (7) generate the same detection waveform signal, which are the first signal and the second signal respectively, and waiting until the first signal and the second signal are both stable; Step 2, remove the first lead (2) from the device to be tested, and connect it to the output end of the first digital signal generator (1), and connect the output end of the second digital signal generator (7) to the second input end of the LMS acquisition device (9) through the second lead (8); Step 3, sending an instruction through the host computer (11) to enable the LMS acquisition device (9) to start collecting the first signal and the second signal, and when the first preset condition is met, the LMS acquisition device (9) completes and stops collecting; Step 4, sending the first signal and the second signal collected by the LMS acquisition device (9) in step 3 to the host computer (11), generating result data after processing, and collating the result data; Step 5: The host computer (11) processes and analyzes the result data to obtain characteristic information of the first signal and the second signal; Step 6, comparing the characteristic information of the first signal and the second signal, and setting a preset reasonable range; if the deviation of the characteristic information of the first signal and the second signal is within the preset reasonable range, it is determined that the connections of all connectors in the rapid change measurement system based on the LMS acquisition device are reliable, and the reliability check is completed; if the deviation of the characteristic information of the first signal and the second signal is not within the preset reasonable range, the connection position of the first digital signal generator (1) in the signal acquisition path is changed and steps 3 to 5 are repeated to determine the fault location.

2. The reliability inspection method of the signal acquisition path in the fast-changing measurement system based on the LMS acquisition device according to claim 1 is characterized in that: In step 1, the detection waveform is a sine function with a frequency of f=10kHz, an amplitude of A=5V, and an initial phase of φ=0.

3. The reliability inspection method of the signal acquisition path in the fast-changing measurement system based on the LMS acquisition device according to claim 2 is characterized in that: The first preset condition in step 3 is specifically: reaching the preset acquisition time t or the preset number of sampling points N, t ≥ 300s, N ≥ 6×10 5 .

4. The reliability inspection method of the signal acquisition path in the fast-changing measurement system based on the LMS acquisition device according to claim 3 is characterized in that: The result data described in step 4 is stored in *.txt format; "arranging the result data" specifically converts the result data from *.txt format to *.unv format.

5. The reliability inspection method of the signal acquisition path in the fast-changing measurement system based on the LMS acquisition device according to claim 4 is characterized in that: The characteristic information described in step 5 includes spectrum shape, peak position and amplitude.

6. The reliability inspection method of the signal acquisition path in the fast-changing measurement system based on the LMS acquisition device according to claim 5 is characterized in that: In step 6, the preset reasonable range is specifically: the spectrum shape similarity of the two signals is ≥80%, the phase value deviation percentage of the peak value is ≤5%, and the amplitude deviation percentage is ≤10%.

7. The reliability inspection method of the signal acquisition path in the fast-changing measurement system based on the LMS acquisition device according to claim 6 is characterized by: In step 6, the connection position of the first digital signal generator (1) is changed and steps 3 to 5 are repeated to determine the fault position: α) removing the first lead (2) from the output end of the first digital signal generator (1), removing the active cable (4) from the output end of the adapter (3) and connecting it to the output end of the first digital signal generator (1), and performing steps 3 to 5 in sequence, and then comparing the characteristic information of the first signal and the second signal. If the deviation of the characteristic information of the first signal and the second signal is within a preset reasonable range, it is determined that the fault is located on the first lead (2) or the adapter (3), and step β1) is performed; if the deviation of the characteristic information of the first signal and the second signal is not within the preset reasonable range, step β2) is performed; β1) Replace a new first lead (2), then connect the output end of the first digital signal generator (1) to the input end of the first lead (2), and perform steps 3 to 5 in sequence to compare the characteristic information of the first signal and the second signal; if the deviation of the characteristic information of the first signal and the second signal is within a preset reasonable range, it is determined that the fault is located on the first lead (2); if the deviation of the characteristic information of the first signal and the second signal is not within the preset reasonable range, it is determined that the fault is located on the adapter (3); and the reliability check is completed; β2) Replace a new active cable (4), then connect the active cable (4) to the output end of the first digital signal generator (1), and perform steps 3 to 5 in sequence to compare the characteristic information of the first signal and the second signal; if the deviation of the characteristic information of the first signal and the second signal is within a preset reasonable range, it is determined that the fault is located on the active cable (4), and the reliability check is completed; if the deviation of the characteristic information of the first signal and the second signal is not within the preset reasonable range, step γ) is performed; γ) The long-distance main cable (6) is removed from the output end of the front switching cabinet (5) and connected to the output end of the first digital signal generator (1), and the characteristic information of the first signal and the second signal are compared after executing steps 3 to 5 in sequence; if the deviation of the characteristic information of the first signal and the second signal is within a preset reasonable range, it is determined that the fault is located in the front switching cabinet (5); if the deviation of the characteristic information of the first signal and the second signal is not within the preset reasonable range, it is determined that the fault is located in the long-distance main cable (6); and the reliability check is completed.

8. The reliability inspection method of the signal acquisition path in the fast-changing measurement system based on the LMS acquisition device according to claim 7 is characterized in that: Step 5 is as follows: Step 5.1, dividing the first signal and the second signal into equal time periods; Step 5.2, analyzing the first signal and the second signal in each time period in the navigator module of the LMS data processing software, respectively, to obtain an average spectrum diagram, a chromatogram, and a slice diagram of the first signal and the second signal; Step 5.3: Utilize the obtained average spectrum diagram, chromatogram and slice diagram to obtain the spectrum shape, peak position and amplitude data of the first signal and the second signal.

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