Coating thickness detection device and method

Abstract

The invention discloses a coating thickness detection device and method, and belongs to the technical field of coating detection. The device comprises a shell, wherein the shell is provided with a beating opening; the pressing part comprises at least two clamping pieces used for clamping the striking part, the clamping pieces are movably inserted into the shell and comprise first connecting rods and second connecting rods, the first connecting rods are hinged to the second connecting rods, the second connecting rods are rotationally connected with the shell through pin shafts, and movement of the first connecting rods is used for driving the second connecting rods to overturn inwards; the striking part comprises a striking rod and at least two clamping blocks arranged on the striking rod; the striking rod is arranged in the striking opening in a penetrating-out mode, and the clamping block is located on a partial overturning track of the free end of the second connecting rod. The first spring is connected between the clamping block and the top of the shell; and the sound processing mechanism is used for collecting the striking sound and analyzing and determining the thickness of the coating according to the striking sound. The paint is knocked in the whole detection process, and the paint thickness detection precision can be improved by combining sound detection.

Description

Technical Field

[0001] This invention relates to the field of coating testing technology, and in particular to a coating thickness testing device and method. Background Technology

[0002] In the treatment of flashover protection for power equipment, PRTV (Peterlee Relational Test Vehicle, a durable in-situ molded anti-flashover composite coating for the external insulation of power equipment) plays a key role, and its coating thickness directly affects the anti-flashover effect and operational safety of the equipment.

[0003] However, current methods for detecting the coating thickness of PRTV mainly rely on manual experience or large, complex testing equipment. Among these methods, manual experience is highly subjective, and the accuracy of the test results is difficult to guarantee. On the other hand, large testing equipment has a complex structure and is usually not easy to carry, making it difficult to meet the needs of rapid on-site testing of equipped PRTVs. Therefore, it is clear that existing testing devices cannot achieve rapid and accurate detection and judgment. Summary of the Invention

[0004] This invention provides a coating thickness detection device and method, aiming to solve the problem that the existing technology cannot quickly and accurately detect and judge the coating thickness of PRTV.

[0005] The first aspect of the present invention provides a coating thickness detection device, comprising:

[0006] The outer casing is provided with a striking port;

[0007] A push-button part is movably inserted into the housing. The push-button part includes a push-button cover and at least two clamping members for clamping the striking part. The two clamping members are hinged to the push-button cover. Each clamping member includes a first link and a second link. The first link is hinged to the second link. The second link is rotatably connected to the housing via a pin. The movement of the first link is used to drive the second link to flip towards the adjacent clamping member.

[0008] The striking part includes a striking rod and at least two locking blocks disposed on the striking rod; the striking rod is disposed protrudingly within the striking port, and the locking blocks are located on a portion of the flipping trajectory of the free end of the second connecting rod;

[0009] A first spring is connected between the snap-fit ​​block and the top of the housing;

[0010] A sound processing mechanism is provided, which collects impact sounds and analyzes the impact sounds to determine the coating thickness.

[0011] In some embodiments of the first aspect, the hinge point between the push-button cover and the clamping member is located inside the connection between the pin and the housing.

[0012] In some embodiments of the first aspect, the housing is further provided with positioning through holes;

[0013] The push-button part also includes a positioning post and a second spring;

[0014] The push-button cover is fixedly connected to the positioning post, the positioning post is inserted into the positioning through hole, and a second spring is provided on the outer sleeve of the positioning post. The second spring is connected between the push-button cover and the bottom of the outer shell.

[0015] In some embodiments of the first aspect, the second link includes a first link body and a second link body;

[0016] The first rod is hinged to the first connecting rod, the first rod is hinged to the second rod, the second rod is flipped away from the striking port, and a third spring is connected between the first rod and the second rod, the third spring being used to reset the second rod after it flips.

[0017] In some embodiments of the first aspect, a positioning roller is also fixed inside the housing;

[0018] The positioning roller is aligned with the striking port, the striking rod is a hollow tube, the striking rod is sleeved on the positioning roller, and the first spring is sleeved outside the positioning roller.

[0019] In some embodiments of the first aspect, a limiting sleeve is fixed inside the housing;

[0020] The limiting sleeve is installed on the periphery of the striking port, and the limiting sleeve is aligned with and connected to the striking port;

[0021] The limiting sleeve is fitted over the striking rod, and the diameter of the limiting sleeve is smaller than the distance between the outer walls of the two opposite sides of the snap-fit ​​blocks.

[0022] In some embodiments of the first aspect, the housing is further provided with a plurality of sound-receiving ports, the plurality of sound-receiving ports are arranged at preset intervals, and the plurality of sound-receiving ports are arranged on the same side as the striking port;

[0023] The sound processing mechanism's acquisition module is aligned with the sound receiving port.

[0024] In some embodiments of the first aspect, the shell surface on which the sound-receiving port is located is a concave arc surface, and the striking port is arranged adjacent to the central axis of the concave arc surface.

[0025] In some embodiments of the first aspect, the sound processing mechanism includes:

[0026] The acquisition module is used to acquire the impact sound and convert the impact sound into a time-domain sound signal;

[0027] The processing module, based on the Fourier transform method, converts the time-domain sound signal into a frequency-domain signal and calculates and extracts frequency features from the frequency-domain signal, wherein the frequency features include the dominant frequency and bandwidth; calculates the peak amplitude based on the time-domain sound signal; combines the frequency features and the peak amplitude into a current feature vector, and calculates the cosine similarity between the current feature vector and multiple preset feature vectors respectively; and determines the coating thickness based on the comparison between the obtained similarity value and a threshold.

[0028] The storage module is used to store the preset feature vector and the current feature vector.

[0029] A second aspect of the present invention provides a coating thickness detection method, which utilizes the coating thickness detection device described in the first aspect, and includes the following steps:

[0030] Press the actuating part to make the striking part strike the coating and produce a striking sound;

[0031] The sound processing mechanism's acquisition module acquires the impact sound and converts the impact sound into a time-domain sound signal;

[0032] The sound processing module is based on the Fourier transform method to convert the time-domain sound signal into a frequency-domain signal, and calculates and extracts frequency features from the frequency-domain signal, wherein the frequency features include the dominant frequency and bandwidth; based on the time-domain sound signal, the amplitude peak value is calculated; the frequency features and the amplitude peak value are combined into a current feature vector, and the cosine similarity between the current feature vector and multiple preset feature vectors is calculated respectively; the coating thickness is determined by comparing the obtained similarity value with a threshold value.

[0033] As can be seen from the above technical solutions, the present invention has the following advantages:

[0034] This embodiment provides a coating thickness detection device and method. Since the pressing part is movably inserted into the housing, the pressing part includes at least two clamping members, each including a first connecting rod and a second connecting rod. The first connecting rod and the second connecting rod are hinged together, and the second connecting rod is rotatably connected to the housing via a pin. The snap block of the striking part is located on a portion of the flipping trajectory of the second connecting rod. Therefore, in application, the striking port is aligned with the coating layer to be detected, and the pressing part is pressed. The first connecting rod of the pressing part can drive the second connecting rod to flip inward around the pin. When the second connecting rod flips to the snap block, it is clamped, and then the striking part is activated. The first spring is compressed by the striking part. As the second link continues to rotate, it gradually moves from the inside to the outside of the bottom of the locking block until it is completely separated from the locking block. Under the action of the first spring, the separated striking part passes through the striking hole and strikes the coating layer. The striking sound is collected by the sound processing mechanism, and the coating thickness is determined based on the sound analysis. The entire detection process is fast, and because the striking part separates at the same position each time, the striking force of the coating is controlled to be the same each time. By using scientific sound comparison and data analysis to detect the sound information returned, the coating thickness can be accurately determined. Attached Figure Description

[0035] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0036] Figure 1 This is a schematic diagram of the vertical cross-sectional structure of a coating thickness detection device provided in an embodiment of the present invention;

[0037] Figure 2 This is a schematic diagram of the cross-sectional structure of a coating thickness detection device provided in an embodiment of the present invention.

[0038] Figure label:

[0039] 1. Outer shell; 10. Striking port; 11. Positioning through hole; 12. Positioning roller; 13. Limiting sleeve; 14. Sound outlet; 15. Pressing port;

[0040] 2. Pressing part; 20. Pressing cover; 21. Clamping component; 210. First connecting rod; 211. Second connecting rod; 2110. First rod body; 2111. Second rod body; 2112. Third spring; 212. Pin; 22. Positioning post; 23. Second spring;

[0041] 3. Striking part; 30. Striking lever; 31. Locking block;

[0042] 4. The first spring;

[0043] 5. Sound processing mechanism; 50. Acquisition module; 51. Processing module; 52. Storage module. Detailed Implementation

[0044] This invention provides a coating thickness detection device and method to solve the technical problem that existing technologies cannot achieve rapid and accurate detection and judgment.

[0045] To make the objectives, features, and advantages of this invention more apparent and understandable, the technical solutions of the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described below are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0046] Please see Figure 1 and Figure 2 The present invention provides a coating thickness detection device, comprising:

[0047] Outer casing 1, the outer casing 1 is provided with a striking port 10;

[0048] The push part 2 is movably inserted into the outer casing 1. The push part 2 includes a push cover 20 and at least two clamping members 21 for clamping the striking part 3. The two clamping members 21 are hinged to the push cover 20. The clamping member 21 includes a first connecting rod 210 and a second connecting rod 211. The first connecting rod 210 and the second connecting rod 211 are hinged. The second connecting rod 211 is rotatably connected to the outer casing 1 through a pin 212. The movement of the first connecting rod 210 is used to drive the second connecting rod 211 to flip towards the adjacent clamping member 21.

[0049] The striking part 3 includes a striking rod 30 and at least two locking blocks 31 disposed on the striking rod 30; the striking rod 30 is disposed protrudingly in the striking port 10, and the locking blocks 31 are located on a portion of the flipping trajectory of the second link 211.

[0050] The first spring 4 is connected between the snap-fit ​​block 31 and the top of the outer casing 1;

[0051] Sound processing unit 5 collects impact sounds and analyzes them to determine the coating thickness.

[0052] During operation in this embodiment, the user presses the cover 20, and the first connecting rod 210 of the pressing part 2 moves towards the bottom of the outer shell 1, causing the second connecting rod 211 to flip inward (flip towards the adjacent clamping member 21). The inwardly flipped second connecting rod 211 gradually approaches the locking block 31 of the striking part 3 until the second connecting rod 211 abuts against the bottom of the locking block 31. As the second connecting rod 211 continues to flip, it causes the striking part 3 to compress the first spring 4 upward, and the second connecting rod 211 gradually moves from the inner side of the bottom of the locking block 31 to the outer side until the second connecting rod 211 is completely separated from the locking block 31. Under the action of the first spring 4, the striking part 3 passes through the striking hole 10 and strikes the coating layer. The striking sound is collected by the sound processing mechanism 5, and the coating thickness is determined based on the analysis of the striking sound.

[0053] In this process, after the second link 211 causes the striking rod 30 to be struck, the reset of the second link 211 can push the striking rod 30 towards the striking port 10, causing the locking block 31 to move out of the flipping trajectory of the second link 211. At this time, pulling the pressing cover 20 upward will drive the second link 211 to rotate, thus completing the reset of the second link 211.

[0054] It should be noted that when striking the surface of the equipment under test, the striking point 3 should avoid the connection parts, edge areas, and areas with obvious defects or damage. Priority should be given to striking areas with flat and uniform coating surfaces to ensure that the sound propagation path is relatively consistent and to reduce detection errors caused by positional differences. For example, for large equipment, multiple striking points should be selected according to a certain grid or matrix distribution to detect the coating thickness at different locations in order to obtain more comprehensive information about the equipment coating. For example, for glass insulator equipment, 4-6 striking points can be evenly selected in the circumferential direction, and several positions at different heights can also be selected in the axial direction for striking detection.

[0055] Compared with existing technologies, the advantages of this embodiment are as follows: First, the detection is fast. As an elastic material, PRTV produces different sound characteristics when it is hit due to different coating thicknesses. The generated sound signal contains information related to the thickness of PRTV. In this embodiment, the entire detection process only requires pressing the pressing part 2 to trigger the striking part 3 to strike the coating and emit a striking sound. The coating thickness quality can be detected by detecting the striking sound. The entire detection speed is fast and does not require a detection process with complex equipment. Second, the detection is accurate. This embodiment is unaffected by the environment. Whether it is equipment detection in an indoor substation or in harsh outdoor natural environments (such as high temperature, high humidity, strong wind, sand and dust), this embodiment can operate stably. The mechanical linkage structure ensures that the striking part 3 is released in the same position each time, and the striking force of the striking part 3 on the coating is the same each time. It strikes the surface of the equipment coated with PRTV with a constant force, accurately controlling possible impact variables. This avoids the problem of existing technologies using electric push rods, where the thrust of electric push rods is easily affected by electromagnetic and high temperature environments, leading to the failure of electric push rods and making it difficult to ensure that the thrust is the same each time.

[0056] In one specific embodiment, such as Figure 1 and Figure 2 As shown, a feasible structure for the push-button 2 is further provided. A retaining strip is provided on the outer side of the push-button cover 20, and a retaining groove is provided on the outer shell 1 to mate with the push-button cover 20. The push-button cover 20 and the outer shell 1 are connected by the sliding engagement of the retaining strip and the retaining groove. A push-button opening 15 is provided on the side of the outer shell 1 opposite to the striking port 10; that is, the push-button opening 15 is located at the top of the outer shell 1, and the striking port 10 is located at the bottom of the outer shell 1. A clamping member 21 is provided on the outer shell 1 and hinged to the bottom of the push-button cover 20. The clamping member 21 passes through the push-button opening 15. Slide it into the outer shell 1. Press the hinge of the cover 20 and the clamp 21. The hinge is located inside the connection between the pin 212 and the outer shell 1. Since the hinge of the cover 20 and the clamp 21 is inside the connection between the pin 212 and the outer shell 1, the first link 210 of the clamp 21 will be located outside the second link 211. In specific implementation, press down on the cover 20. The first link 210 located outside will cause the second link 211 located inside to flip inward, so that the second link 211 flips inward.

[0057] In one embodiment, such as Figure 1 and Figure 2As shown, in order to make the movement of the pressing part 2 more stable, the outer shell 1 is also provided with a positioning through hole 11; the pressing part 2 also includes a positioning post 22 and a second spring 23; the pressing cover 20 is fixedly connected to the positioning post 22, the positioning post 22 is inserted into the positioning through hole 11, and a third spring 2112 is provided on the outer shell of the positioning post 22. The third spring 2112 is connected between the pressing cover 20 and the bottom of the outer shell 1. In specific implementation, the pressing cover 20 will move vertically upward or vertically downward stably under the positioning guidance of the positioning post 22 and the positioning through hole 11. The pressing cover 20 can only move vertically and cannot rotate, so as not to cause the clamping part 21 to be misaligned with the locking block 31 due to rotation, thus ensuring the normal operation of the pressing part 2 and the striking part 3. The second spring 23 can reset the pressing cover 20 when the user does not press it.

[0058] In one embodiment, such as Figure 1 and Figure 2 As shown, to improve the reset efficiency, the second connecting rod 211 includes a first rod body 2110 and a second rod body 2111. The first rod body 2110 is hinged to the first connecting rod 210, and the first rod body 2110 is hinged to the second rod body 2111. The second rod body 2111 flips away from the striking port 10. A third spring 2112 is connected between the first rod body 2110 and the second rod body 2111. The third spring 2112 is used to reset the second rod body 2111 after it flips. Therefore, when the second connecting rod 211 flips upward, the second rod body 2111 forms a straight rod that abuts against the locking block 31 under the action of gravity and hinge. When the second connecting rod 211 disengages from the locking block... When block 31 is about to flip downwards, the second link 211 is in an upward tilted position. The second link 2111 can flip upwards when it touches the locking block 31. The first link 2110 and the second link 2111 form a folded structure, which can avoid the locking block 31, allowing the second link 211 to quickly return to its downward position. When the second link 211 is flipped into an downward tilted position, the second link 2111 will flip downwards under the action of gravity. Under the elastic action of the third spring 2112, the first link 2110 and the second link 2111 will re-form a straight rod structure. There is no need to move the striking part 3 outside the movement trajectory of the second link 211 before returning the second link 211 to its original position. The return speed is fast and the efficiency is high.

[0059] In this embodiment, as Figure 2As shown, the first rod 2110 has a mounting lug at one end adjacent to the second rod 2111, and the second rod 2111 has a lug at one end adjacent to the first rod 2110. Both the lug and the mounting lug have through holes for mounting the pin 212. The lug is inserted into the mounting lug, and multiple through holes are arranged coaxially. The pin 212 is inserted into multiple through holes to achieve the hinge connection between the first rod 2110 and the second rod 2111. A third spring 2112 is sleeved on the pin 212. The third spring 2112 is a torsion spring. One end of the torsion spring is connected to the first rod 2110, and the other end of the torsion spring is connected to the second rod 2111.

[0060] In one specific embodiment, such as Figure 1 As shown, in order to make the striking movement of the striking part 3 more stable, a positioning roller 12 is also fixed on the outer shell 1; the positioning roller 12 is aligned with the striking port 10, the striking rod 30 is a hollow tube, the hollow tube striking rod 30 is sleeved on the positioning roller 12, and the first spring 4 is sleeved on the outside of the positioning roller 12. Under the positioning guidance of the positioning roller 12, the striking rod 30 can move along the axial direction of the positioning roller 12. For example, the striking rod 30 moves upward along the positioning roller 12 and compresses the first spring 4, or the striking rod 30 moves downward along the positioning roller 12 and pops out under the action of the first spring 4.

[0061] In one embodiment, such as Figure 1 As shown, to prevent the striking rod 30 from moving too far, a limiting sleeve 13 is fixed on the outer shell 1. The limiting sleeve 13 is installed on the periphery of the striking port 10, and the limiting sleeve 13 is aligned with and connected to the striking port 10. The limiting sleeve 13 is sleeved on the outside of the striking rod 30, and the diameter of the limiting sleeve 13 is smaller than the distance between the outer walls of the two locking blocks 31 on opposite sides. In specific implementation, the striking rod 30 is inserted into the limiting sleeve 13, and the locking block 31 can be locked on the limiting sleeve 13 to limit the movement of the hollow tube-shaped striking rod 30.

[0062] In one specific embodiment, such as Figure 1 As shown, in order to improve the sound reception effect, the outer shell 1 is also provided with a sound receiving port 14. The sound receiving port 14 is arranged on the same side as the striking port 10, and multiple sound receiving ports 14 are arranged at equal intervals. The acquisition module 50 of the sound processing mechanism 5 is aligned with the sound receiving port 14. In specific implementation, when the striking part 3 strikes out from the striking port 10 and emits a striking sound, the sound is transmitted to the sound receiving port 14 arranged on the same side. The acquisition part of the sound processing mechanism 5 can pick up the sound immediately, and the sound reception effect is good.

[0063] In one embodiment, such as Figure 1 As shown, in order to further enhance the sound reception effect, the shell surface of the outer shell 1 with the sound port 14 is a concave arc surface, and the striking port 10 is arranged near the central axis of the concave arc surface. The concave arc surface of the shell surface can converge the striking sound, so that the sound processing mechanism 5 can receive a more concentrated and stronger sound signal, thereby improving the sound reception effect.

[0064] In this embodiment, as Figure 1 As shown, the outer casing 1 includes a housing and a bottom. The bottom is provided with a microphone 14 and a striking port 10. The bottom is detachably connected to the housing. When a problem occurs with the internal components of the outer casing 1, it can be quickly disassembled for easy maintenance.

[0065] In one specific embodiment, such as Figure 1 As shown, a feasible structure for the sound processing mechanism 5 is further provided, including: a acquisition module 50, used to acquire the impact sound and convert the impact sound into a time-domain sound signal; a processing module 51, used to convert the time-domain sound signal into a frequency-domain signal based on the Fourier transform method, and to calculate and extract frequency features from the frequency-domain signal, wherein the frequency features include the dominant frequency and the bandwidth; to calculate the amplitude peak value based on the time-domain sound signal; to combine the frequency features and the amplitude peak value into a current feature vector, and to calculate the cosine similarity between the current feature vector and multiple preset feature vectors, and to determine the coating thickness based on the comparison of the obtained similarity value with a threshold; and a storage module 52, used to store the preset feature vectors.

[0066] It should be noted that when the striking head strikes the surface of the equipment coated with PRTV with a constant force, the generated sound signal contains information related to the thickness of the PRTV. The acquisition module 50 converts the acquired sound signal into an electrical signal and transmits it to the processing module 51. The processing module 51 uses the above data processing method to analyze the sound signal and compares it with the pre-stored data in the storage module 52. Based on the similarity of the sound features, it determines the current coating thickness of the PRTV. For example, if the similarity of the current feature with the sound feature data corresponding to a certain thickness reaches a set threshold, it is determined that the current coating thickness of the PRTV is close to that thickness, thereby concluding whether the coating thickness is sufficient.

[0067] It should be noted that this embodiment extracts the dominant frequency, bandwidth, and peak amplitude of the impact sound. The dominant frequency is the frequency corresponding to the maximum amplitude in the power spectrum. Generally, a higher dominant frequency indicates a larger elastic modulus and stiffness of the coating, and vice versa. Thinner PRTVs typically produce a higher dominant frequency when impacted, while thicker coatings produce a relatively lower dominant frequency. A narrower bandwidth indicates that the sound encounters more interfaces and pores during propagation within the coating. Different thicknesses of PRTVs correspond to different bandwidths. Thinner coatings may correspond to a relatively narrow bandwidth or a bandwidth with a larger proportion of high frequencies, while thicker coatings may correspond to a relatively wide bandwidth or a bandwidth with a larger proportion of low frequencies. Thin coatings, due to their lighter weight and relatively weaker coupling with the substrate, exhibit different energy reflection and scattering during sound propagation compared to thick coatings, resulting in significant fluctuations in sound amplitude at certain frequencies. Thick coatings, due to their greater weight and relatively tighter coupling with the substrate, experience more uniform energy loss and smoother amplitude changes during sound propagation.

[0068] The operation of this embodiment includes the following steps:

[0069] S1, Acquisition module 50 acquires impact sounds;

[0070] S2, the acquisition module 50 converts the impact sound into a time-domain sound signal;

[0071] S3, the processing module 51 converts the time-domain sound signal into a frequency-domain signal based on the Fourier transform method, and calculates and extracts frequency features from the frequency-domain signal. The frequency features include the main frequency and the bandwidth.

[0072] S4, Processing module 51 calculates the peak amplitude based on the time-domain sound signal;

[0073] S5. The processing module 51 combines the frequency features and amplitude peaks into a current feature vector, calculates the cosine similarity between the current feature vector and multiple preset feature vectors called from the storage module 52, and determines the coating thickness based on the obtained similarity value compared with a threshold.

[0074] After adopting the above settings, this embodiment collects impact sounds and performs feature extraction and analysis on the impact sounds collected in real time. Among them, the main frequency, bandwidth and amplitude peak value are used to detect the thickness of the coating. The main frequency can also reflect the stiffness of the coating, and the bandwidth reflects the interface and pore conditions inside the coating, which fully covers the coating condition. Then, it is compared with the data of the preset feature vector in the storage module 52. If the similarity between the features of the real-time sound signal and the sound feature data corresponding to a certain thickness reaches the set threshold, it is determined that the current coating thickness is close to that thickness, thereby concluding whether the coating thickness is sufficient.

[0075] In one embodiment, a feasible structure for S1 is further provided, wherein the acquisition module 50 acquires the impact sound, and the core component of the acquisition module 50 is a high-sensitivity electret condenser microphone, which can accurately capture various sound signals generated during the impact.

[0076] In one embodiment, a further implementable structure for S2 is provided, wherein the acquisition module 50 further includes an amplifier and an analog-to-digital converter (ADC), wherein the preamplifier is responsible for initially amplifying the weak acoustic electrical signal so that the ADC can accurately convert the analog signal into a digital signal.

[0077] It should be noted that, in order to reduce the impact of external electromagnetic interference on the acquisition of sound signals, the acquisition module 50 is enclosed in a metal shield, which effectively reduces the impact of external electromagnetic interference on the acquisition of sound signals.

[0078] In one embodiment, an implementable structure for S3 is further provided, specifically including the following steps:

[0079] S30. Based on the Fourier transform method, convert the time-domain sound signal into a frequency-domain signal.

[0080] In this example, the formula for the Fourier transform is:

[0081]

[0082] In the above formula, Representing a frequency domain signal, it represents the complex value at frequency index k. Its real part reflects the amplitude of the cosine component of that frequency element, that is, the contribution of the cosine wave of that frequency to the original signal; its imaginary part reflects the amplitude of the sine component of that frequency element, that is, the contribution of the sine wave of that frequency to the original signal. It is a time-domain signal, that is, the digital signal acquired by the acquisition module 50 and converted from analog to digital in time index. The value at point N represents the intensity of the sound signal at different times. N is the signal length, i.e., the number of sampling points involved in the FFT calculation. It determines the range and precision of the calculation; the more sampling points, the more refined the signal analysis. It is a frequency index, with values ​​ranging from 0 to N-1, and different values... The values ​​correspond to different frequency components, and can be changed by... The value can be used to obtain the characteristics of the signal at different frequencies; It is a time index, with a value range of 0 to N-1, corresponding one-to-one with the sampling points in time; It is the imaginary unit, satisfying It plays a crucial mathematical transformation role in the formula, helping to achieve the conversion from the time domain to the frequency domain.

[0083] It should be noted that sound signals are essentially time-domain signals that vary with time, and the Fast Fourier Transform (FFT) is an efficient algorithm of the Discrete Fourier Transform (DFT), which can convert time-domain signals into frequency-domain signals, making it easier to analyze the frequency composition of the signal. In this embodiment, by analyzing the sound signal generated by the impact through FFT, the energy distribution of different frequency components can be obtained, and then the frequency features related to the thickness of the PRTV can be extracted.

[0084] S31. Calculate and extract the main frequency from the frequency domain signal. The main frequency is the frequency corresponding to the maximum amplitude in the power spectrum.

[0085] S32. Calculate and extract the bandwidth from the frequency domain signal.

[0086] Specifically, the bandwidth extraction steps include:

[0087] S320. Determine the maximum amplitude of the frequency domain signal;

[0088] S321. The product of the maximum amplitude and the preset percentage is determined as the power threshold, wherein the preset percentage is set to 20% in this example;

[0089] S322. Select the frequency range that is greater than the power threshold within the frequency domain signal, and determine the obtained frequency range as the bandwidth.

[0090] In one embodiment, a further implementable structure for S4 is provided, which analyzes the time-domain signal sequence over a certain time period to find the maximum value. and minimum value By calculating the maximum value of the time-domain signal within a certain time period and minimum value The peak amplitude was obtained. , The larger the value, the more drastic the change in the intensity of the sound signal during this period, that is, the more obvious the change in the energy of the sound.

[0091] Among them, here It is the maximum value of the sound signal intensity within a selected time period, representing the strongest intensity the sound reaches during that time period. This represents the minimum sound signal strength within that time period, indicating the weakest sound intensity during that period.

[0092] In one embodiment, an implementable structure for S5 is further provided, specifically including the following steps:

[0093] S50. Combine the frequency characteristics and amplitude peak values ​​into the current feature vector.

[0094] S51. Calculate the cosine similarity between the current feature vector and multiple preset feature vectors called from the storage module 52.

[0095] Specifically, the real-time acquired sound feature data and the pre-stored sound feature data in storage module 52 are represented as vectors. By calculating the cosine similarity between them, the approximation of the current PRTV coating thickness and the pre-stored sample thickness can be accurately determined. The cosine similarity value ranges from... Between these two values, the closer the value is to 1, the more similar the directions of the two vectors are, meaning the more similar the sound features are. This also means that the thickness of the currently detected PRTV is closer to the thickness of the pre-stored samples. This is because when the directions of two vectors are similar, it indicates that the sound features they represent have consistent trends in all dimensions, thus allowing us to infer that the thickness of the corresponding PRTV is also relatively similar.

[0096] In this embodiment, the formula for cosine similarity is:

[0097]

[0098] In the above formula, It is a vector and dot product, It is the current feature vector. It is a preset feature vector. It is the magnitude of the current feature vector. It is the modulus of the preset feature vector.

[0099] It should be noted that the dot product reflects the sum of the products of the components of two vectors in each dimension. The larger the dot product, the higher the consistency of the two vectors in direction. For example, in sound feature vectors, the size of the dot product reflects the similarity between real-time acquired sound features and pre-stored sound features in dimensions such as frequency and amplitude.

[0100] In this embodiment, the preset feature vector is composed of the main frequency, bandwidth and peak amplitude of the sound of the coating with a preset thickness being struck. One preset feature vector represents the sound feature combination of a PRTV sample with one thickness, and multiple preset feature vectors represent the sound feature combination of PRTV samples with different thicknesses. The cosine similarity between the current feature vector and different preset feature vectors is calculated to obtain multiple similarity values. The corresponding coating thickness is then determined based on the similarity values.

[0101] S52. Determine the coating thickness by comparing the obtained similarity value with the threshold. When the similarity value is greater than or equal to the threshold, the coating of the paint is considered to be similar to the corresponding known coating, thereby determining the quality of the coating.

[0102] For example, if the threshold is set to 0.9 (90%), and the similarity value calculated between the current feature vector and the preset feature vector of a certain thickness is greater than 0.9, then the current coating thickness is considered to be a certain thickness, thereby determining whether the quality of the current coating is qualified.

[0103] In one embodiment, a storage module 52 is further provided. The storage module 52 is used to store the current feature vector and multiple preset feature vectors. That is, the current feature vector of the same device at different time points will be stored and become a historical feature vector. It is possible to compare and analyze the detection data of the same device at different time points, understand the aging trend and performance changes of PRTV, and provide a scientific basis for the formulation of equipment maintenance plans.

[0104] In one embodiment, before step S3, the following step is further included: filtering the time-domain audio signal, specifically using a Butterworth low-pass filter to remove high-frequency noise interference and retain the effective audio signal frequency band.

[0105] Based on the above embodiments, an application process example will be presented below:

[0106] Bring the debugged equipment to the environment of the device under test;

[0107] Select and align the coating with a flat, uniform area;

[0108] Conduct several pre-strike tests, maintain a stable operating posture and force application method, reduce the impact of human factors on the striking force to ensure that the equipment can work properly. For example, when performing a striking operation with a handheld device, try to keep your arm stable and apply the striking force vertically downward to avoid oblique strikes or excessive fluctuations in force.

[0109] Each detection location should be subjected to at least three repeated impact tests. After each impact, the device automatically collects and records the sound signal and analyzes the results. After multiple tests are completed, the processing module 51 performs statistical analysis on the multiple detection results of the same location, removes outliers, and then calculates the average value as the final detection result for that location. For example, if one of the three detection results for a certain location deviates significantly from the other two values, the processing module 51 will automatically identify the outlier and exclude it. Then, it will average the remaining two valid results to obtain the PRTV coating thickness judgment result for that location.

[0110] The device automatically stores detailed data from each test, including test time, location, equipment number, impact position, impact force, sound signal characteristics, and the final test result, into storage module 52. Simultaneously, it wirelessly uploads the data in real-time to a remote server or monitoring center, enabling centralized data management and backup. This data can be used not only for current equipment status assessment and acceptance but also for providing crucial reference for subsequent equipment maintenance, performance analysis, and testing method optimization.

[0111] Based on the above embodiments, a coating thickness detection method is provided below, which applies the aforementioned coating thickness detection device and includes the following steps:

[0112] Press the actuating part 2 to cause the striking part 3 to strike the coating and produce a striking sound;

[0113] The acquisition module 50 acquires the impact sound and converts the impact sound into a time-domain sound signal;

[0114] The processing module 21 converts the time-domain sound signal into a frequency-domain signal based on the Fourier transform method, and calculates and extracts frequency features from the frequency-domain signal, where the frequency features include the dominant frequency and bandwidth; it calculates the peak amplitude based on the time-domain sound signal; it combines the frequency features and the peak amplitude into a current feature vector, and calculates the cosine similarity between the current feature vector and multiple preset feature vectors respectively, and determines the coating thickness by comparing the obtained similarity value with a threshold.

[0115] In the working process of this application, by pressing the pressing part 2, the striking part 3 can strike the coating and emit a striking sound. The sound processing mechanism on the coating thickness detection device can simultaneously collect the striking sound and compare the similarity of the striking sound to determine the thickness of the struck coating. The whole process integrates striking, collection and analysis into one, which can quickly and accurately detect and judge the coating thickness.

[0116] In summary, the advantages of this device are: high flexibility and convenience in testing; through scientific sound comparison and data analysis, it avoids the subjectivity and errors of manual experience-based judgment, accurately determining whether the PRTV coating thickness meets requirements; the entire testing process is rapid, enabling the testing of a large number of devices in a short time, improving the efficiency of acceptance work; the design fully considers the complex operating conditions and diverse working environments of different power equipment. Whether in indoor substation equipment testing or in harsh outdoor natural environments such as high temperature, high humidity, strong winds, and sandstorms, the device can operate stably, accurately collecting and analyzing sound signals, unaffected by excessive environmental interference, demonstrating good adaptability and reliability; the architecture of the processing module 51 has good scalability, reserving multiple data interfaces and function expansion interfaces. In the future, with the continuous development of technology and the emergence of new testing needs, the device can be easily upgraded in software and expanded in hardware; for example, new sensor modules can be added to detect other parameters related to the status of power equipment, such as temperature, humidity, and electric field strength, thereby achieving comprehensive testing and evaluation of power equipment.

[0117] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0118] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

[0119] Finally, it should be noted that in this paper, relational terms such as first and second are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations.

Claims

1. A coating thickness detection device, characterized by, The utility model relates to a kind of sound processing mechanism and its implementation method, including: Shell, the shell is equipped with hitting mouth; Pushing part, the pushing part is movably inserted into the shell, the pushing part includes push cover, at least two clamping pieces for clamping hitting part, two The clamping piece is hinged with the push cover, the clamping piece includes first connecting rod and second connecting rod, the first connecting rod is hinged with the second connecting rod, the second connecting rod is rotatably connected with the shell by pin shaft, the movement of the first connecting rod is used to drive the second connecting rod overturn direction adjacent the clamping piece; Hitting part, the hitting part includes hitting rod and at least two clamping blocks provided on the hitting rod;The hitting rod is provided in the hitting mouth, and the clamping block is located in the part of the free end of the second connecting rod overturning track; First spring, the first spring is connected between the clamping block and the top of the shell; Sound processing mechanism, the sound processing mechanism collects hitting sound, and determines coating thickness according to the hitting sound analysis.

2. The coating thickness detection apparatus according to claim 1, characterized by The hinge of the push cover and the clamping piece is located inside the connection of the pin shaft and the shell.

3. The coating thickness detection apparatus according to claim 2, characterized by The shell is also provided with positioning through hole; The pushing part further includes positioning column and second spring; The push cover is fixedly connected with the positioning column, the positioning column is inserted into the positioning through hole, the positioning column is provided with the second spring, and the second spring is connected between the push cover and the bottom of the shell.

4. The coating thickness detection apparatus according to claim 2, characterized by The second connecting rod includes first rod body and second rod body; The first rod body is hinged with the first connecting rod, the first rod body is hinged with the second rod body, the second rod body overturns towards the direction away from the hitting mouth, the third spring is connected between the first rod body and the second rod body, and the third spring is used to reset the second rod body after overturning.

5. The coating thickness detection apparatus according to claim 1, characterized by The positioning roller is also fixed in the shell; The positioning roller is aligned with the hitting mouth, the hitting rod is a hollow pipe, the hitting rod is sleeved on the positioning roller, and the first spring is sleeved outside the positioning roller.

6. The coating thickness detection apparatus according to claim 5, characterized by The limiting sleeve is fixed in the shell; The limiting sleeve is installed on the circumferential side of the hitting mouth, the limiting sleeve is aligned with and communicated with the hitting mouth; The limiting sleeve is sleeved outside the hitting rod, and the diameter of the limiting sleeve is less than the distance between the outer walls of the opposite sides of the two clamping blocks.

7. The coating thickness detection apparatus according to claim 1, characterized by The shell is also provided with a plurality of sound collecting mouths, and the plurality of sound collecting mouths are arranged at a predetermined interval. The collection module of the sound processing mechanism is aligned with the sound collecting mouth.

8. The coating thickness detection apparatus according to claim 7, characterized by The shell surface of the shell provided with the sound collecting mouth is concave arc surface, and the hitting mouth is adjacent to the central axis of the concave arc surface.

9. The coating thickness detection apparatus according to claim 1, characterized by The sound processing mechanism, comprising: Collection module, for collecting hitting sound, and converting the hitting sound into time-domain sound signal; The processing module converts the time-domain sound signal into a frequency-domain signal based on a Fourier transform method, and extracts frequency features from the frequency-domain signal, wherein the frequency features include a main frequency and a frequency bandwidth; an amplitude peak value is calculated based on the time-domain sound signal; the frequency features and the amplitude peak value are combined into a current feature vector, and cosine similarities of the current feature vector with a plurality of preset feature vectors are respectively calculated, and a coating thickness is determined according to a comparison of a similarity value obtained with a threshold value; The storage module is configured to store the preset feature vectors and the current feature vector.

10. A coating thickness detection method characterized by, The coating thickness detection device according to any one of claims 1 to 9 comprises the following steps: The pressing part is pressed to make the hitting part hit the coating and emit a hitting sound; The collection module of the sound processing mechanism collects the hitting sound and converts the hitting sound into a time-domain sound signal; The processing module of the sound processing mechanism converts the time-domain sound signal into a frequency-domain signal based on a Fourier transform method, and extracts frequency features from the frequency-domain signal, wherein the frequency features include a main frequency and a frequency bandwidth; an amplitude peak value is calculated based on the time-domain sound signal; the frequency features and the amplitude peak value are combined into a current feature vector, and cosine similarities of the current feature vector with a plurality of preset feature vectors are respectively calculated, and a coating thickness is determined according to a comparison of a similarity value obtained with a threshold value.

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