A vacuum film leak detection system and method based on ultrasonic and vibration signal combined detection

Abstract

This invention discloses a vacuum membrane leak detection system and method based on joint detection of ultrasonic and vibration signals, belonging to the field of vacuum membrane leak detection technology in vacuum pre-compression. The system includes an ultrasonic signal module, a vibration signal module, a signal processing module, and a detection probe. The detection probe has an ultrasonic sensor at its top and multiple vibration sensors at its bottom. The ultrasonic sensor detects ultrasonic signals, and the ultrasonic signal module processes the ultrasonic signals to obtain processed ultrasonic signals. The vibration sensors detect vibration signals, and the vibration signal module processes the vibration signals to obtain processed vibration signals. The signal processing module receives the processed ultrasonic and vibration signals, performs spectral analysis and wavelet analysis on them, and determines the leak direction. The signal processing module also connects to a terminal to send the leak direction to the terminal. This invention can significantly improve leak detection efficiency.

Description

Technical Field

[0001] This invention belongs to the field of vacuum membrane leak detection technology in vacuum pre-compression, specifically relating to a vacuum membrane leak detection system and method based on the combined detection of ultrasonic and vibration signals. Background Technology

[0002] Vacuum preloading is a widely used method for treating soft soil foundations. Its basic principle is to reinforce the soil by laying a vacuum-sealed membrane on the soil surface and drawing a vacuum, utilizing the atmospheric pressure difference. However, during actual construction, sharp particles in the soil can easily puncture the vacuum-sealed membrane, causing the vacuum level to fail to meet design requirements. This affects the foundation reinforcement effect and, in severe cases, can even lead to engineering quality accidents. Therefore, timely and effective leak detection and rapid repair of leaks during vacuum preloading are crucial measures to ensure project quality.

[0003] Currently, commonly used traditional leak detection methods include the soap and water application method and the alcohol spray method. These methods are simple to operate and suitable for applications with smooth surfaces and regular structures. However, the vacuum preloading environment is complex, and the vacuum membrane often exhibits irregular shapes such as folds, bends, and partial coverage. Traditional leak detection methods are inefficient in such complex conditions and cannot meet actual engineering needs. Furthermore, leaks caused by soil particles puncturing the vacuum membrane are usually extremely small and difficult to detect with the naked eye. Simultaneously, the significant pressure difference across the vacuum membrane causes gas to pass through the punctures at extremely high speeds. The high-frequency ultrasonic waves caused by this high-speed airflow and the vibration of the membrane surface can serve as identifying features of leaks. Therefore, to effectively adapt to the complex state of the vacuum membrane during vacuum preloading construction, it is necessary to develop a highly efficient leak detection device specifically for vacuum preloading conditions to improve detection accuracy. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a vacuum membrane leak detection system and method based on the joint detection of ultrasonic and vibration signals. It is easy to operate, can greatly improve the leak detection efficiency, shorten the time interval from the appearance of the leak to its discovery, and help maintain the stability of the vacuum level of the vacuum pre-compression system.

[0005] This invention provides the following technical solution: In the first aspect, a vacuum membrane leak detection system based on the joint detection of ultrasonic and vibration signals is provided, including an ultrasonic signal module, a vibration signal module, a signal processing module, and a detection probe; Both the ultrasonic signal module and the vibration signal module are connected to the signal processing module; The detection probe is equipped with an ultrasonic sensor at the top and multiple vibration sensors at the bottom. The ultrasonic sensor is connected to an ultrasonic signal module, and the vibration sensors are connected to a vibration signal module. The ultrasonic sensor is used to detect the ultrasonic signal generated when airflow passes through the vacuum membrane leak. The ultrasonic signal module receives the ultrasonic signal and performs buffering, filtering, gain adjustment and anti-aliasing processing on the ultrasonic signal to obtain the ultrasonic processed signal. The vibration sensor is used to detect the vibration signal generated when the airflow passes through the vacuum membrane leak point. The vibration signal module receives the vibration signal and performs charge conversion, high-pass filtering, gain compensation and band-pass filtering on the vibration signal to obtain the vibration processed signal. The signal processing module receives ultrasonic processing signals and vibration processing signals, performs spectrum analysis and wavelet analysis on the ultrasonic processing signals and vibration processing signals to determine whether there are any leaks, and if there are leaks, determines the direction of the leaks. The signal processing module is also connected to the terminal and sends the leak direction to the terminal.

[0006] As an optional technical solution of the present invention, the ultrasonic signal module includes an ultrasonic signal preamplifier, an ultrasonic signal prefilter, an ultrasonic signal main amplifier, and an ultrasonic signal main filter connected in sequence.

[0007] As an optional technical solution of the present invention, the vibration signal module includes a vibration signal preamplifier, a vibration signal prefilter, a vibration signal main amplifier, and a vibration signal main filter connected in sequence.

[0008] As an optional technical solution of the present invention, the signal processing module includes an analog-to-digital converter and a controller connected to each other; the analog-to-digital converter is used to convert ultrasonic processing signals and vibration processing signals into digital signals; the controller is used to perform spectrum analysis and wavelet analysis on the output signal of the analog-to-digital converter to determine whether there is a leak, and if there is a leak, to determine the location of the leak.

[0009] As an optional technical solution of the present invention, the detection probe has an equilateral tetrahedral hollow structure.

[0010] As an optional technical solution of the present invention, the top of the detection probe is threadedly connected to an ultrasonic sensor via an ultrasonic sensor mounting seat; ultrasonic focusing baffles are installed on three sides of the top of the detection probe, and the ultrasonic focusing baffles on the three sides form a horn-shaped focusing head.

[0011] As an optional technical solution of the present invention, the three vertices at the bottom of the detection probe are all connected to the vibration sensor via a vibration sensor mounting seat threaded connection. The bottom of the vibration sensor mounting base is provided with a rubber strip mounting groove for mounting the rubber strip.

[0012] As an optional technical solution of the present invention, the vibration sensor mounting base includes a longitudinal axis rotation limiting component, a rotation axis limiting component, a horizontal limiting component, a horizontal axis rotation limiting component, and a sensor mounting cover; the longitudinal axis rotation limiting component is fixedly installed on the top of the rotation axis limiting component, and the longitudinal axis rotation limiting component is rotatably connected to the apex of the bottom of the detection probe; the sensor mounting cover is located below the rotation axis limiting component, the horizontal axis rotation limiting component is fixedly connected to the sensor mounting cover and rotatably connected to the rotation axis limiting component, and the two ends of the horizontal axis rotation limiting component are fixedly connected to the horizontal limiting component.

[0013] In a second aspect, a detection method is provided based on the vacuum membrane leak detection system based on the joint detection of ultrasonic and vibration signals described in the first aspect, comprising: suspending the detection probe above the vacuum membrane, sweeping the target vacuum pre-compression area according to a pre-acquired grid order, and during the sweeping process, the signal processing module determines the suspected leak area based on the signal time difference of multiple vibration sensors; Move the detection probe to any position in the suspected leak area, adjust the position of the vibration sensor to fit the surface of the vacuum membrane and leave it for a preset time, and the terminal will obtain the direction of the leak. Repeat the following steps until the suspected leak area is reduced to no larger than a preset area size threshold. The reduced suspected leak area is then taken as the leak location. The following steps include: In the suspected leak area, the detection probe is moved towards the leak point, the position of the vibration sensor is readjusted to fit the surface of the vacuum membrane, and it is left to stand for a preset time. The terminal then obtains the re-determined leak point direction.

[0014] Compared with the prior art, the beneficial effects of the present invention are: This invention provides a vacuum membrane leak detection method based on the combined detection of ultrasonic and vibration signals. The method uses an ultrasonic sensor to detect the ultrasonic signal generated when airflow passes through the vacuum membrane leak, and a vibration sensor to detect the vibration signal generated when airflow passes through the vacuum membrane leak. The ultrasonic and vibration signals are processed by a signal processing module to locate the leak direction. The method is simple to operate, can significantly improve leak detection efficiency, shorten the time interval between the appearance of a leak and its discovery, and help maintain the stability of the vacuum level of the vacuum pre-compression system. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the vacuum membrane leak detection system in an embodiment of the present invention; Figure 2 This is a schematic diagram of a handheld device in an embodiment of the present invention; Figure 3 This is a schematic diagram of the internal structure of the handheld device in an embodiment of the present invention; Figure 4 This is a schematic diagram of the detection probe in an embodiment of the present invention; Figure 5 This is a schematic diagram of the internal structure of the detection probe in an embodiment of the present invention; Figure 6 This is a schematic diagram of the vibration sensor mounting base in an embodiment of the present invention; Figure 7 This is a cross-sectional view of the vibration sensor mounting base in an embodiment of the present invention.

[0016] In the diagram: 1. Handheld device; 2. Rubber hose; 3. Detection probe; 1-1. Cable outlet; 1-2. Display screen; 1-3. Operation buttons; 1-4. Switch button; 1-5. Battery compartment cover; 1-6. Battery compartment; 1-7. Screw hole mounting post; 3-1. Vibration sensor mounting base; 3-2. Ultrasonic sensor mounting base; 3-3. Wiring terminal; 3-4. Ultrasonic focusing baffle; 3-5. Thin hollow metal tube; 3-6. Vertical axis rotation limiting component; 3-7. Rotation axis limiting component; 3-8. Horizontal limiting component; 3-9. Horizontal axis rotation limiting component; 3-10. Sensor mounting cover. 3-11 Adhesive strip mounting slot; 3-12 Sensor mounting threaded hole; 3-13 Sensor cable outlet; 4-1 Ultrasonic signal preamplifier; 4-2 Ultrasonic signal pre-filter; 4-3 Ultrasonic signal main amplifier; 4-4 Ultrasonic signal main filter; 4-5 Vibration signal preamplifier; 4-6 Vibration signal pre-filter; 4-7 Vibration signal main amplifier; 4-8 Vibration signal main filter; 4-9 Analog-to-digital converter; 4-10 Controller; 4-11 Bluetooth transmitter module; 4-12 Integrated sensor interface; 4-13 Circuit board. Detailed Implementation

[0017] The present invention will be further described below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and should not be used to limit the scope of protection of the present invention.

[0018] Example 1 This embodiment provides a vacuum membrane leak detection system based on the combined detection of ultrasonic and vibration signals, such as... Figure 1 As shown, it includes a handheld device 1, a rubber hose 2, and a detection probe 3.

[0019] The rubber hose 2 connects the cable outlet 1-1 of the handheld device 1 to the centralized terminal 3-3 on the top of the detection probe 3. The sensor cable passes through the inside of the rubber hose 2 and merges into the integrated sensor interface 4-12 inside the handheld device 1. The rubber hose 2 can be bent freely and maintains a fixed shape after the external force is removed, allowing the operator to flexibly adjust the spatial orientation of the detection probe 3 to meet the detection needs of vacuum membrane areas beyond the direct contact range.

[0020] like Figure 2 and Figure 3As shown, the handheld device 1 has a display screen 1-2 on its upper surface, used to display information such as battery level, signal strength, and Bluetooth connection status. The front of the handheld device 1 has operation buttons 1-3 and a power button 1-4, used to adjust device parameters and control power on / off, respectively, facilitating quick operation by the user during testing. The bottom of the handheld device 1 has a battery compartment cover 1-5 and a battery compartment 1-6. A battery is installed in the battery compartment 1-6 to power the main circuit board 4-13, and the circuit board is electrically connected to the two electrodes of the battery compartment 1-6. The lower half of the handheld device 1, where the operation buttons 1-3 are located, is smaller than the upper half, where the display screen 1-2 is located. The lower half is easier to hold, while the upper half can accommodate a larger display screen 1-2, facilitating clear reading of displayed information. The internal cavity of the handheld device 1 has screw-hole mounting posts 1-7, connected to the housing, used to install and fix the main circuit board 4-13. The side wall of the handheld device 1 has a cable outlet 1-1 for connecting sensor cables passing through the rubber hose 2. The frame of the handheld device 1 has chamfered edges for easy gripping and operation.

[0021] like Figure 3 As shown, the handheld device 1 has an internal cavity for mounting the main circuit board 4-13. The main circuit board 4-13 integrates an ultrasonic signal module, a vibration signal module, and a signal processing module. Both the ultrasonic signal module and the vibration signal module are connected to the signal processing module. The detection probe 3 has an ultrasonic sensor at its top and multiple vibration sensors at its bottom. The ultrasonic sensor is connected to the ultrasonic signal module, and the vibration sensors are connected to the vibration signal module.

[0022] The ultrasonic sensor detects 20-100kHz ultrasonic signals generated by complex turbulence when high-speed airflow passes through a small hole in the vacuum membrane leak point. The ultrasonic signal module receives the ultrasonic signal and performs buffering, filtering, gain adjustment, and anti-aliasing processing to obtain a processed ultrasonic signal. The vibration sensor detects low-frequency vibration signals of the vacuum membrane caused by high-speed airflow passing through the small hole in the vacuum membrane leak point. The vibration signal module receives the vibration signal and performs charge conversion, high-pass filtering, gain compensation, and band-pass filtering to obtain a processed vibration signal. The signal processing module receives the processed ultrasonic and vibration signals and performs spectral and wavelet analysis on them to determine the presence of a leak point. If a leak point exists, its direction is determined. The signal processing module is also connected to a terminal to send the leak point direction to the terminal.

[0023] Furthermore, the ultrasonic sensor is a piezoelectric ultrasonic sensor, and the vibration sensor is a piezoelectric thin-film sensor.

[0024] The ultrasonic signal module includes an ultrasonic signal preamplifier 4-1, an ultrasonic signal pre-filter 4-2, an ultrasonic signal main amplifier 4-3, and an ultrasonic signal main filter 4-4 connected in sequence. The ultrasonic signal preamplifier is a FET voltage amplifier used to extract the weak voltage signal from the ultrasonic sensor, perform signal buffering and impedance matching to suppress signal attenuation caused by load effects. The ultrasonic signal pre-filter is a second-order active Sallen-Key filter used to filter out DC bias and out-of-band low-frequency environmental interference, preventing large-amplitude noise from causing nonlinear saturation in the subsequent amplifier circuit. The ultrasonic signal main amplifier is a programmable gain amplifier used to dynamically adjust the signal amplitude to the range of the analog-to-digital converter, improving system range coverage and quantization accuracy. The ultrasonic signal main filter is an adjustable bandpass switched-capacitor filter used to lock the center frequency of the leakage characteristic ultrasonic waves, significantly attenuate background noise from out-of-band vacuum pumps, and also act as an anti-aliasing filter to ensure that the sampled data conforms to the Nyquist sampling theorem.

[0025] The vibration signal module includes a vibration signal preamplifier 4-5, a vibration signal prefilter 4-6, a vibration signal main amplifier 4-7, and a vibration signal main filter 4-8 connected in sequence. The vibration signal preamplifier is an electrometer-level operational amplifier used to linearly convert the minute charge signal generated by the vibration sensor into a voltage signal and eliminate the influence of the distributed capacitance of the connecting cable on the measurement sensitivity. The vibration signal prefilter is an active Butterworth high-pass filter used to cut off the quasi-static ultra-low frequency charge drift signal generated by the slow settling of the membrane surface during vacuum preloading, ensuring that the signal link only responds to high-frequency dynamic mechanical vibration. The vibration signal main amplifier is a programmable gain amplifier used to compensate for the nonlinear attenuation of the vibration signal with propagation distance, dynamically adjusting the signal amplitude to the range of the analog-to-digital converter to improve the system's range coverage and quantization accuracy. The vibration signal main filter is an adjustable bandpass OTA-C filter used to suppress out-of-band electromagnetic interference above the target vibration frequency, thereby extracting a high signal-to-noise ratio leakage point vibration waveform.

[0026] The signal processing module includes an analog-to-digital converter 4-9 and a controller 4-10 connected to each other. The analog-to-digital converter 4-9 is used to convert ultrasonic processing signals and vibration processing signals into digital signals; the controller 4-10 is used to perform spectrum analysis and wavelet analysis on the output signal of the analog-to-digital converter 4-9 to determine whether there are any leaks, and if there are leaks, to determine the location of the leaks.

[0027] Furthermore, the analog-to-digital converter is a multi-channel synchronous sampling successive approximation analog-to-digital converter, used to synchronously sample and quantize the analog signals output by the ultrasonic and vibration signal acquisition modules, mapping continuously changing voltage and charge signals into digital signals with time coherence for subsequent calculations.

[0028] The signal processing module also includes a Bluetooth transmission module 4-11, which sends the detection results to the terminal.

[0029] like Figure 4 and Figure 5 As shown, the detection probe 3 has an equilateral tetrahedral hollow structure. The entire interior is hollow, allowing free flow of air at the vacuum membrane leak point during detection. The tetrahedral frame structure is composed of thin, hollow metal tubes 3-5, allowing the sensor cable to extend along the inside of the hollow tubes, resulting in a compact structure and neat wiring.

[0030] The top of the detection probe 3 is threadedly connected to the ultrasonic sensor via the ultrasonic sensor mounting base 3-2; ultrasonic focusing baffles 3-4 are installed on the three sides of the top of the detection probe 3, and the ultrasonic focusing baffles 3-4 on the three sides form a horn-shaped focusing head, which is used to focus the ultrasonic waves scattered at the leak point toward the ultrasonic sensor and improve the acquisition intensity of the ultrasonic signal.

[0031] The three vertices at the bottom of the detection probe 3 are all threadedly connected to vibration sensors via vibration sensor mounting bases 3-1. The three vibration sensor mounting bases 3-1 are arranged in a spatial triangular array, and the vibration sensors are respectively installed in the corresponding three mounting bases. They are used to detect the low-frequency vibration signal of the vacuum membrane caused by high-speed airflow passing through the small hole of the vacuum membrane leak point. The time difference of the signals received by the three sensors can be used to calculate the position of the leak point relative to the detection probe 3, thereby improving the leak point location efficiency. The bottom of the vibration sensor mounting base 3-1 is provided with an adhesive strip mounting groove 3-11 for installing an adhesive strip. The adhesive strip is a temporary low-viscosity adhesive strip, which is used to temporarily fix the detection probe 3 to the uneven surface of the vacuum membrane during detection, forming a stable three-point support. This allows the vibration sensor housing 3-10 to fit tightly against the vacuum membrane, providing mechanical fixation while also serving as an acoustic impedance matching layer, improving the transmission efficiency of low-frequency surface wave signals from the membrane surface to the sensor.

[0032] like Figure 6 and Figure 7 As shown, the vibration sensor mounting base 3-1 includes a longitudinal axis rotation limiting component 3-6, a rotation axis limiting component 3-7, a horizontal limiting component 3-8, a horizontal axis rotation limiting component 3-9, and a sensor mounting cover 3-10, which work together to achieve multi-degree-of-freedom steering, enabling the vibration sensor to adjust its orientation to fit the uneven vacuum membrane surface during detection.

[0033] The longitudinal axis rotation limiting component 3-6 is fixedly installed on top of the rotation axis limiting component 3-7, and the longitudinal axis rotation limiting component 3-6 is rotatably connected to the apex of the bottom of the detection probe 3. The sensor mounting cover 3-12 is located below the rotation axis limiting component 3-7. The horizontal axis rotation limiting component 3-9 is fixedly connected to the sensor mounting cover 3-10 and rotatably connected to the rotation axis limiting component 3-7. The two ends of the horizontal axis rotation limiting component 3-9 are fixedly connected to the horizontal limiting component 3-8.

[0034] The vibration sensor mounting base 3-1 has a sensor mounting threaded hole 3-12 at its bottom for mounting the vibration sensor, which facilitates sensor replacement. The vibration sensor cable enters the rubber hose 2 through the sensor cable outlet 3-13 and merges into the integrated sensor interface 4-12 inside the handheld device 1.

[0035] The structure of the ultrasonic sensor mounting base 3-2 is the same as that of the vibration sensor mounting base 3-1, except that it does not have a rubber strip mounting groove, so it will not be described again here.

[0036] Example 2 This embodiment provides a vacuum membrane leak detection method based on joint detection of ultrasonic and vibration signals, including: The detection probe 3 is suspended above the vacuum membrane and swept across the target vacuum pre-compression area according to a pre-acquired grid sequence. During the sweeping process, the signal processing module determines the suspected leak area based on the signal time difference of multiple vibration sensors. The target vacuum pre-compression area is pre-divided into several grids.

[0037] Move the detection probe 3 to any position in the suspected leak area, adjust the position of the vibration sensor to fit the surface of the vacuum membrane and leave it for a preset time, and the terminal will obtain the direction of the leak.

[0038] Repeat the following steps until the suspected leak area is reduced to no larger than a preset area size threshold. The reduced suspected leak area is then taken as the leak location. The following steps include: In the suspected leak area, the detection probe 3 is moved towards the leak point, the position of the vibration sensor is readjusted to fit the surface of the vacuum membrane, and it is left to stand for a preset time. The terminal then obtains the re-determined leak point direction.

[0039] In this embodiment, the preset area size threshold is 10*10cm.

[0040] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are used only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0041] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0042] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A vacuum membrane leak detection system based on combined ultrasonic and vibration signal detection, characterized in that, It includes an ultrasonic signal module, a vibration signal module, a signal processing module, and a detection probe (3); Both the ultrasonic signal module and the vibration signal module are connected to the signal processing module; The detection probe (3) is equipped with an ultrasonic sensor at the top and multiple vibration sensors at the bottom. The ultrasonic sensor is connected to an ultrasonic signal module, and the vibration sensors are connected to a vibration signal module. The ultrasonic sensor is used to detect the ultrasonic signal generated when airflow passes through the vacuum membrane leak. The ultrasonic signal module receives the ultrasonic signal and performs buffering, filtering, gain adjustment and anti-aliasing processing on the ultrasonic signal to obtain the ultrasonic processed signal. The vibration sensor is used to detect the vibration signal generated when the airflow passes through the vacuum membrane leak point. The vibration signal module receives the vibration signal and performs charge conversion, high-pass filtering, gain compensation and band-pass filtering on the vibration signal to obtain the vibration processed signal. The signal processing module receives ultrasonic processing signals and vibration processing signals, performs spectrum analysis and wavelet analysis on the ultrasonic processing signals and vibration processing signals to determine whether there are any leaks, and if there are leaks, determines the direction of the leaks. The signal processing module is also connected to the terminal and sends the leak direction to the terminal.

2. The vacuum membrane leak detection system based on combined ultrasonic and vibration signal detection according to claim 1, characterized in that, The ultrasonic signal module includes an ultrasonic signal preamplifier (4-1), an ultrasonic signal prefilter (4-2), an ultrasonic signal main amplifier (4-3), and an ultrasonic signal main filter (4-4) connected in sequence. 3.The vacuum film pinhole detection system based on the combination of ultrasonic and vibration signals according to claim 1, characterized in that, The vibration signal module includes a vibration signal preamplifier (4-5), a vibration signal prefilter (4-6), a vibration signal main amplifier (4-7), and a vibration signal main filter (4-8) connected in sequence. 4.The vacuum film pinhole detection system based on the combination of ultrasonic and vibration signals according to claim 1, wherein, The signal processing module includes an analog-to-digital converter (4-9) and a controller (4-10) that are connected to each other. The analog-to-digital converter (4-9) is used to convert ultrasonic processing signals and vibration processing signals into digital signals; The controller (4-10) is used to perform spectrum analysis and wavelet analysis on the output signal of the analog-to-digital converter (4-9) to determine whether there is a leak. If there is a leak, the location of the leak is determined. 5.The vacuum film pinhole detection system based on the combination of ultrasonic and vibration signals according to claim 1, wherein, The detection probe (3) has an equilateral tetrahedral hollow structure.

6. The vacuum membrane leak detection system based on combined ultrasonic and vibration signal detection according to claim 5, characterized in that, The top of the detection probe (3) is threadedly connected to the ultrasonic sensor via the ultrasonic sensor mounting base (3-2); The detection probe (3) has ultrasonic focusing baffles (3-4) installed on its three sides. The ultrasonic focusing baffles (3-4) on the three sides form a horn-shaped focusing head.

7. The vacuum membrane leak detection system based on combined ultrasonic and vibration signal detection according to claim 5, characterized in that, The three vertices at the bottom of the detection probe (3) are all threaded to the vibration sensor via the vibration sensor mounting base (3-1); The bottom of the vibration sensor mounting base (3-1) is provided with a rubber strip mounting groove (3-11) for mounting the rubber strip.

8. The vacuum membrane leak detection system based on joint detection of ultrasonic and vibration signals according to claim 7, characterized in that, The vibration sensor mounting base (3-1) includes a longitudinal axis rotation limiting component (3-6), a rotation axis limiting component (3-7), a horizontal limiting component (3-8), a horizontal axis rotation limiting component (3-9), and a sensor mounting cover (3-10). The longitudinal axis rotation limiting component (3-6) is fixedly installed on the top of the rotation axis limiting component (3-7), and the longitudinal axis rotation limiting component (3-6) is rotatably connected to the apex of the bottom of the detection probe (3); The sensor mounting cover (3-10) is located below the rotating shaft limiting member (3-7). The horizontal shaft rotating limiting member (3-9) is fixedly connected to the sensor mounting cover (3-10) and rotatably connected to the rotating shaft limiting member (3-7). The two ends of the horizontal shaft rotating limiting member (3-9) are fixedly connected to the horizontal limiting member (3-8).

9. A detection method based on the vacuum membrane leak detection system based on the combined detection of ultrasonic and vibration signals as described in claims 1-8, characterized in that, include: The detection probe (3) is suspended above the vacuum membrane and swept across the target vacuum pre-compression area according to the pre-acquired grid order. During the sweeping process, the signal processing module determines the suspected leak area based on the signal time difference of multiple vibration sensors. Move the detection probe (3) to any position in the suspected leak area, adjust the position of the vibration sensor to fit the surface of the vacuum membrane and leave it for a preset time, and the terminal obtains the direction of the leak. Repeat the following steps until the suspected leak area is reduced to no larger than a preset area size threshold. The reduced suspected leak area is then taken as the leak location. The following steps include: Move the detection probe (3) in the direction of the suspected leak in the area of ​​the leak, readjust the position of the vibration sensor so that it fits the surface of the vacuum membrane and let it stand for a preset time, and the terminal obtains the re-determined direction of the leak.

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