Non-contact detection system based on impact elastic waves

Abstract

The invention provides a non-contact detection system based on impact elastic waves, and belongs to the technical field of quality safety detection of civil engineering, buildings, roads, bridges and hydraulic engineering, and the non-contact detection system comprises a laser vibration meter, an excitation emitter, a high-pressure gas tank, a steering base, an excitation ball and a detection host; the laser vibration meter is used for remotely measuring the vibration signal without contact, and compared with a traditional mode that an acceleration sensor must be attached to the measured surface for detection, the method has the advantage that inhibition or interference to original vibration when the acceleration sensor is pressed on the measured surface is avoided. Compared with a mode of measuring vibration by using an acceleration sensor, the method does not need contact, especially for test objects which are inconvenient to contact by the acceleration sensor, such as high altitude, climbing dead corners, high-temperature surfaces, underwater and the like, so that the personal safety of operators is better guaranteed while the test efficiency and range are effectively improved.

Description

Technical Field

[0001] The present invention relates to the technical field of quality safety detection of civil engineering, construction, roads and bridges, and water conservancy projects, and in particular to a non-contact detection system based on impact elastic waves. Background Art

[0002] Non-destructive testing technology is an emerging engineering science that has developed rapidly in recent years. Its definition is that it uses the phenomenon that the physical quantities of certain physical properties of a substance will change due to defects or differences in its organizational structure without destroying the original state and chemical properties of the substance to be tested. On the premise of not damaging the performance and morphology of the inspected object, certain detection means are used to test, display and evaluate these changes, so as to understand and evaluate the properties, state or internal structure of the inspected object such as materials, products, and equipment components. The impact elastic wave detection method is an important detection method in non-destructive testing technology.

[0003] Impact elastic wave testing is widely used in nondestructive testing of various civil engineering projects. Whether it's roadbed filling and pavement construction for highways and railways, or the construction and maintenance of bridges, tunnels, and other important structures, impact elastic wave testing can be found everywhere.

[0004] Based on the detection principle of impact elastic waves, a metal hammer is usually used to knock on the surface to be tested to generate collisions and vibrations, thereby triggering impact elastic waves. The vibration signal is then collected by an acceleration sensor attached to the surface to be tested. By processing and analyzing the vibration signal, the volume, thickness, strength, defects and other physical parameters of the test object can be obtained. In patent CN 109001300 A, a sound insulation device suitable for impact echo audio detection is disclosed. The patent discloses a non-contact detection method that uses a microphone to indirectly collect vibrations of the surface to be tested, which adds a lot to the field of non-destructive testing based on elastic waves. However, this method still requires personnel to press the sound insulation pad to fit the microphone to the surface to be tested and cover it, thereby isolating it from external noise interference.

[0005] Therefore, whether using traditional accelerometers or impact echo acoustic testing, the sensor must always be in direct or indirect contact with the surface being tested. This means the area being tested must be within direct reach of the tester or test equipment. This significantly limits the efficiency and application scope of impact elastic wave testing. Improving both efficiency and coverage is a pressing issue.

[0006] Therefore, there is an urgent need in this field for a technical solution that can effectively improve detection efficiency and detection range.

[0007] The information disclosed in this background technology section is only intended to enhance understanding of the overall background of the invention and should not be regarded as an admission or any form of suggestion that the information constitutes the prior art already known to a person skilled in the art. Summary of the Invention

[0008] The purpose of the present invention is to provide a technical solution that can effectively improve detection efficiency and detection range.

[0009] To achieve the above object, the present invention provides the following solutions:

[0010] A non-contact detection system based on impact elastic waves, characterized by comprising: a laser vibrometer, an excitation transmitter, a high-pressure gas tank, a steering base, an excitation ball and a detection host;

[0011] The laser vibrometer's detection laser transmission and reception path is mounted on the steering base in parallel with the emission direction of the excitation transmitter, or the relative angle between the laser vibrometer's detection laser transmission and reception path and the emission direction of the excitation transmitter is changed, as long as the excitation ball emitted by the excitation transmitter can collide with the test object being detected by the laser vibrometer; a high-pressure gas tank is installed on the steering base to provide emission power for the excitation transmitter;

[0012] The vibration launcher is equipped with a valve and a launch tube. The front end of the valve is connected to the high-pressure gas tank. The high-pressure gas in the high-pressure gas tank is released and closed by opening and closing the valve. The vibration ball is placed inside the launch tube of the vibration launcher.

[0013] The laser vibrometer remotely detects the vibration signal on the surface of the test object through laser, and the laser vibrometer is connected to the detection host.

[0014] Optionally, an object is emitted through the air by an excitation transmitter to collide with the surface of the test object to generate vibration and form an impact elastic wave, and the vibration signal of the test object is collected through the air by a laser vibrometer. The vibration signal is analyzed and processed by the detection host to realize non-contact non-destructive testing of impact elastic waves.

[0015] Optionally, the vibration launcher uses compressed air to launch the vibration ball, or uses the energy generated by releasing the stored force of elastic materials, electromagnetic conversion and gunpowder explosion as the launching power.

[0016] Optionally, the vibration ball includes a metal sphere, an ice ball or icicle made of water-absorbing material that has absorbed water and frozen, or a projectile made of plastic, rubber, or clay; the vibration ball only serves as a kinetic energy carrier that collides with the test object and generates a vibration signal, and is not limited to a specific material and shape.

[0017] Optionally, the vibrometer and the laser vibrometer are used in pairs, or different numbers of vibrometers or laser vibrometers are used to improve test efficiency and accuracy.

[0018] Optionally, the detection host includes signal processing and analysis functions. The detection host itself can be independent of other components and connected through signal cables or wireless technology, and can also be integrated with other components to form a whole.

[0019] Optionally, during the test, it is necessary to place an appropriate amount of vibration balls inside the vibration transmitter in advance, adjust the steering base so that the laser vibrometer and the emission port of the vibration transmitter are aligned with the test object, and by quickly opening and closing the valve inside the vibration transmitter, a portion of the high-pressure gas stored in the high-pressure gas tank can be quickly released. The released high-pressure gas pushes a vibration ball pre-placed inside the vibration transmitter to be ejected along the launch tube. The ejected vibration ball flies in the air along the direction of the launch tube under the action of inertia, and finally collides with the surface of the test object to induce impact elastic waves. After the laser vibrometer remotely detects the test signal on the surface of the test object, it transmits the vibration signal to the detection host for analysis and processing.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] 1. The present invention uses a laser vibrometer to remotely measure vibration signals without contact. Compared with the traditional acceleration sensor that must be placed in close contact with the measured surface for detection, this method avoids the suppression or interference of the original vibration caused by the acceleration sensor pressing on the measured surface.

[0022] 2. Compared with the vibration measurement method using acceleration sensors, the present invention does not require contact, especially for test objects that are inconvenient for acceleration sensors to contact, such as high altitude, climbing blind spots, high-temperature surfaces, and underwater. While effectively improving the test efficiency and scope, it also better ensures the personal safety of operators.

[0023] 3. The excitation transmitter used in the present invention launches the excitation object to perform remote excitation. Compared with the traditional contact excitation method of using hand hammer, electromagnetic excitation and other contact excitation methods to generate impact elastic waves, it has the advantages of high excitation efficiency, small excitation distance limit, no secondary excitation and low requirements on the operating skills of the excitation personnel. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0025] Figure 1 A schematic diagram of the system structure provided by an embodiment of the present invention.

[0026] 1-Laser vibrometer, 2-Vibration transmitter, 3-High-pressure gas tank, 4-Steering base, 5-Laser beam, 6-Vibration ball, 7-Test object, 8-Detection host. DETAILED DESCRIPTION

[0027] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0028] The purpose of the present invention is to provide a technical solution that can effectively improve detection efficiency and detection range.

[0029] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0030] Example 1:

[0031] This embodiment provides a non-contact detection system based on impact elastic waves, such as Figure 1 As shown, it includes: a laser vibrometer 1, an excitation transmitter 2, a high-pressure gas tank 3, a steering base 4, an excitation ball 6 and a detection host 8;

[0032] The laser vibrometer 1 is mounted on a steering base 4 so that the detection laser's transmission and reception path is parallel to the emission direction of the excitation transmitter 2. Alternatively, the relative angle between the detection laser's transmission and reception path and the emission direction of the excitation transmitter 2 can be changed, as long as the excitation ball 6 emitted by the excitation transmitter 2 can collide with the test object 7 being detected by the laser vibrometer 1. A high-pressure gas tank 3 is mounted on the steering base 4 to provide emission power for the excitation transmitter 2.

[0033] The vibration launcher 2 is provided with a valve and a launch tube. The front end of the valve is connected to the high-pressure gas tank 3. The high-pressure gas in the high-pressure gas tank 3 is released and closed by opening and closing the valve. The vibration ball 6 is placed inside the launch tube of the vibration launcher 2.

[0034] Laser vibrometer 1 uses laser light to remotely detect vibration signals on the surface of test object 7. Laser vibrometer 1 is connected to a detection host 8. Laser vibrometer 1 can remotely detect vibration signals on the surface of test object 7 using laser light. Laser beam 5 is a schematic representation of the laser trajectory of laser vibrometer 1 (not a physical object). Test object 7 is an example model; it can be any surface.

[0035] In one embodiment, an object is emitted through the air by an excitation transmitter 2 to collide with the surface of a test object 7 to generate vibrations and form impact elastic waves, and a vibration signal of the test object 7 is collected through the air by a laser vibrometer 1, and the vibration signal is analyzed and processed by a detection host 8 to achieve non-contact impact elastic wave non-destructive testing.

[0036] In one embodiment, the vibration launcher 2 uses compressed air to launch the vibration ball 6, or utilizes the energy generated by releasing stored energy from an elastic material, electromagnetic conversion, or explosive combustion as the launch power. Each of these launch power sources ultimately launches the vibration ball 6 through the air onto the test object 7, causing a collision, and can all be considered embodiments of the present invention.

[0037] In one embodiment, the vibration ball 6 includes a metal ball, an ice ball or icicle made of water-absorbing material that has absorbed water and frozen, or a projectile made of plastic, rubber, or soil; the vibration ball 6 only serves as a kinetic energy carrier that collides with the test object 7 and generates a vibration signal, and is not limited to a specific material and shape.

[0038] In one embodiment, the excitation transmitter 2 and the laser vibrometer 1 are used in pairs, or different numbers of excitation transmitters 2 or laser vibrometers 1 are used to improve test efficiency and accuracy.

[0039] In one embodiment, the detection host 8 includes signal processing and analysis functions. The detection host 8 itself can be independent of other components and connected through signal cables or wireless technology, and can also be integrated with other components to form a whole.

[0040] In one embodiment, during testing, an appropriate number of excitation balls 6 are pre-placed inside the excitation transmitter 2. The steering base 4 is adjusted so that the emission ports of the laser vibrometer 1 and the excitation transmitter 2 are aligned with the test object 7. By quickly opening and closing the valve inside the excitation transmitter 2, a portion of the high-pressure gas stored in the high-pressure gas tank 3 can be quickly released. The released high-pressure gas pushes a pre-placed excitation ball 6 inside the excitation transmitter 2 to be ejected along the launch tube. The ejected excitation ball 6 flies in the air along the direction of the launch tube under the action of inertia, and eventually collides with the surface of the test object 7, thereby generating impact elastic waves. After the laser vibrometer 1 remotely detects the test signal on the surface of the test object 7, it transmits the vibration signal to the detection host 8 for analysis and processing.

[0041] In one embodiment, the system requires a power supply and a transport device for actual testing. Once the system is moved to the desired testing area, the steering base is used to align the exciter and laser vibrometer with the test object. The laser vibrometer features a built-in indicator laser beam, which can be used to confirm their orientation. For optimal results, the distance between the exciter ball emitted by the exciter and the laser vibrometer's detection focus on the test object surface should be approximately 10 centimeters.

[0042] The impact point of the launched vibrating ball on the test object should be approximately 10 cm from the spot where the vibrometer's indicator laser beam illuminates the test object's surface. Once the vibrating ball is aligned with the test object's surface, the vibrating ball can be launched. Upon impact with the test object, the launched vibrating ball induces vibration. The laser vibrometer then transmits the detected vibration signal to the test host for processing and determination of the desired test parameters.

[0043] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. Reference can be made to the common and similar parts between the various embodiments. For the systems disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple, and the relevant parts can be referred to the method description.

[0044] This document uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only intended to help understand the method and core concept of the present invention. At the same time, those skilled in the art will find that the specific implementation methods and application scopes may vary based on the concept of the present invention. In summary, the contents of this specification should not be construed as limiting the present invention.

Claims

1. A non-contact detection system based on impact elastic waves, characterized in that: include: Laser vibrometer (1), excitation transmitter (2), high-pressure gas tank (3), steering base (4), excitation ball (6) and detection host (8); The laser vibrometer (1) is mounted on a steering base (4) so that the detection laser transmission and reception route is parallel to the emission direction of the excitation transmitter (2), or the relative angle between the detection laser transmission and reception route of the laser vibrometer (1) and the emission direction of the excitation transmitter (2) is changed, as long as the excitation ball (6) emitted by the excitation transmitter (2) can collide with the test object (7) detected by the laser vibrometer (1); a high-pressure gas tank (3) is mounted on the steering base (4) to provide emission power for the excitation transmitter (2); The excitation transmitter (2) is provided with a valve and a launch tube, the front end of the valve is connected to the high-pressure gas tank (3), and the high-pressure gas in the high-pressure gas tank (3) is released and closed by switching the valve. The excitation ball (6) is placed inside the launch tube of the excitation transmitter (2); The laser vibrometer (1) remotely detects vibration signals on the surface of a test object (7) through laser, and the laser vibrometer (1) is connected to a detection host (8).

2. The non-contact detection system based on impact elastic waves according to claim 1, characterized in that: An object is emitted through the air by an excitation transmitter (2) to collide with the surface of a test object (7) to generate vibrations and form impact elastic waves, and a vibration signal of the test object (7) is collected through the air by a laser vibrometer (1), and the vibration signal is analyzed and processed by a detection host (8), thereby realizing non-contact non-destructive testing of impact elastic waves.

3. The non-contact detection system based on impact elastic waves according to claim 1, characterized in that: The excitation launcher (2) uses compressed air to launch the excitation ball (6), or uses the energy generated by releasing the stored force of elastic material, electromagnetic conversion and gunpowder explosion as the launching power.

4. The non-contact detection system based on impact elastic waves according to claim 1, characterized in that: The vibration ball (6) includes a metal ball, an ice ball or icicle made of water-absorbing material after absorbing water and freezing, or a projectile made of plastic, rubber, or soil; the vibration ball (6) only serves as a kinetic energy carrier that collides with the test object (7) and generates a vibration signal, and is not limited to a specific material and shape.

5. The non-contact detection system based on impact elastic waves according to claim 1, characterized in that: The excitation transmitter (2) and the laser vibrometer (1) are used in pairs, or different numbers of excitation transmitters (2) or laser vibrometers (1) are used in combination to improve test efficiency and accuracy.

6. The non-contact detection system based on impact elastic waves according to claim 1, characterized in that: The detection host (8) includes signal processing and analysis functions. The detection host (8) itself can be independent of other components and connected through signal cables or wireless technology, and can also be integrated with other components to form a whole.

7. The non-contact detection system based on impact elastic waves according to claim 1, characterized in that: During the test, it is necessary to place an appropriate amount of excitation balls (6) inside the excitation transmitter (2) in advance, adjust the steering base (4) so that the laser vibrometer (1) and the emission port of the excitation transmitter (2) are aligned with the test object (7), and by quickly opening and closing the valve inside the excitation transmitter (2), a portion of the high-pressure gas stored in the high-pressure gas tank (3) can be quickly released. The released high-pressure gas pushes an excitation ball (6) pre-placed inside the excitation transmitter (2) to be ejected along the emission tube. The ejected excitation ball (6) flies in the air along the direction of the emission tube under the action of inertia, and finally collides with the surface of the test object (7) to induce shock elastic waves. After the laser vibrometer (1) remotely detects the test signal on the surface of the test object (7), it transmits the vibration signal to the detection host (8) for analysis and processing.

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