A vibration measuring device for disease detection

Abstract

This invention relates to the field of vibration measurement technology, and in particular to a vibration measurement device for detecting road defects. The device includes: a vibration sensing unit that outputs vibration characteristic signals representing transient road surface vibrations via a contact and a vibration-sensitive component; a visual acquisition unit for continuously capturing images of the road surface to be tested; a constant pressure adjustment unit for modulating the contact pressure between the contact and the road surface based on the pressure signal; a feature extraction module for extracting road surface texture roughness to determine the target contact pressure before the contact with the road surface; a feature analysis module for plotting vibration amplitude envelope curves based on the vibration characteristic signals to analyze defect characteristics; and a stability analysis and pressure compensation module for determining the baseline stability of the vibration characteristic signals to compensate for the target contact pressure. This invention overcomes detection response lag through visual feedforward adjustment, achieving accurate identification of internal material defects and adaptive compensation of contact pressure.

Description

Technical Field

[0001] This invention relates to the field of vibration measurement technology, and in particular to a device for detecting road surface defects using vibration signals generated by contact rolling. Background Technology

[0002] In the field of nondestructive testing, vibration measurement technology, as a means to directly reflect the internal structural state of materials, has been widely used in road inspection and equipment condition monitoring. Existing road inspection solutions based on vibration principles mostly employ indirect measurement methods, such as installing accelerometers inside the chassis or tires of inspection vehicles to indirectly infer road conditions through the vehicle's own vibrations. However, the signals acquired in this way are mixed with a large number of interference factors such as vehicle dynamic loads, suspension responses, and driving speeds, resulting in a low signal-to-noise ratio. This makes it difficult to accurately locate the microscopic positions of defects and even more difficult to effectively distinguish between macroscopic geometric defects (such as potholes and protrusions) and internal material defects (such as looseness and microcracks). Furthermore, existing vibration detection solutions generally use a fixed preload contact method, which cannot adjust the detection pressure in real time according to changes in road surface roughness and texture grade. This makes it difficult to guarantee the stability and consistency of vibration signals, and lacks a control architecture for multi-source information fusion, leaving vibration detection and visual perception isolated from each other.

[0003] Chinese patent application publication number CN121066027A discloses a fully automated road defect inspection and positioning system. This system employs a method of mounting a detection roller at the rear of an inspection vehicle, with a spring pressing the roller against the road surface. When the detection roller passes over macroscopic defects such as potholes or protrusions, the roller frame swings at an angle. An angle sensor detects this change and triggers a PLC controller to control a marking nozzle to mark the defect location with paint. Simultaneously, a GPS positioning module records the geographical coordinates of the defect. However, this solution still has the following technical shortcomings: First, the detection response has an inherent lag, making early prediction impossible. This solution relies on the angle change caused by the physical compaction of the defect by the detection roller to trigger detection, essentially a passive detection mode that responds after contact. When the inspection vehicle travels at high speed, the detection roller compacts the defect area in a very short time. Although the angle sensor can capture the transient angle change, the paint spraying action of the marking nozzle has an execution delay, resulting in a large deviation between the marked position and the actual defect location. Furthermore, the system cannot predict the severity of the defect before contact, nor can it actively adjust the contact state. When the detection roller encounters deep pits or high protrusions, it will suffer severe mechanical impact, shortening the equipment's lifespan.

[0004] Secondly, this method can only detect macroscopic geometric defects and cannot identify internal material defects in the pavement. Using an angle sensor as the core detection element, this method can only sense the rigid oscillation of the roller frame. Its detection capability is limited to macroscopic defects such as ruts, potholes, and protrusions that have already formed clear geometric boundaries. For internal material defects such as slight looseness, lack of compactness, microcracks, or shallow voids, because these have not yet developed into macroscopic geometric deformation, the detection roller will not produce a sufficiently large angular oscillation when passing over them. Therefore, these early-stage defects cannot be effectively identified; only existing potholes can be detected, and it cannot provide early warning of pavement defects that are about to form.

[0005] Third, the system lacks a visual feedforward mechanism and refined pressure control methods. The detection roller relies on the single preload of the top spring to press against the road surface, and the contact pressure is not adjustable. When the roughness or texture grade of the road surface changes, the fixed spring preload cannot dynamically adapt to the road surface condition. This leads to problems such as severe roller vibration and decreased signal-to-noise ratio on rough road sections, while on smooth road sections, excessive contact pressure may accelerate roller wear. The system cannot pre-adjust the contact pressure before the detection roller reaches the area of ​​road surface condition change, resulting in insufficient initiative and refinement in overall control.

[0006] In summary, existing technologies suffer from problems such as delayed detection response, inability to identify internal material defects, and lack of visual feedforward and adaptive pressure adjustment capabilities. Therefore, overcoming the delayed detection response, protecting detection components from impact damage, improving the perception of material defects, and achieving visual feedforward-based contact pressure pre-calibration and adaptive correction are pressing technical problems that need to be solved in this field. Summary of the Invention

[0007] Therefore, the present invention provides a vibration measurement device for detecting defects, which overcomes the problems of delayed detection response and difficulty in identifying internal material defects caused by the lag of contact pressure adjustment behind changes in road surface condition in the prior art.

[0008] To achieve the above objectives, the present invention provides a vibration measuring device for disease detection, comprising, The vibration sensing unit includes a sensor base and a contact, and a vibration-sensitive component disposed between the sensor base and the contact, for outputting a vibration characteristic signal characterizing the transient jump of the contact contacting the road surface to be detected based on the vibration-sensitive component; A visual acquisition unit, including a camera, is used to continuously capture images of the road surface to be detected in front of the vibration sensing unit; The constant pressure regulating unit includes a power component mounted on a sensor base and a constant pressure detection component embedded in the power component, which is used to modulate the contact pressure between the contact and the road surface to be detected by the power component based on the pressure signal output by the constant pressure detection component. Pressure control unit, which includes, The feature extraction module is connected to the visual acquisition unit and the constant pressure adjustment unit respectively, and is used to extract the texture roughness of the road surface to be detected, so as to generate adjustment instructions and determine the target contact pressure of the constant pressure adjustment unit before the contactor contacts the road surface to be detected; The feature analysis module is connected to the vibration sensing unit and the constant pressure regulating unit respectively. It plots the vibration amplitude envelope curve based on the vibration feature signal to analyze the damage characteristics of the road surface to be detected. A stability analysis module, connected to the feature analysis module, is used to analyze the vibration amplitude envelope curve to determine the baseline stability of the vibration feature signal; A pressure compensation module, which is connected to the stability analysis module and the constant pressure adjustment unit respectively, is used to compensate the target contact pressure between the contact and the road surface to be tested by the power component based on the baseline stability.

[0009] Furthermore, the texture roughness is determined based on the extraction and analysis of texture features from the image of the road surface to be detected, so as to determine the degree of influence of the roughness of the road surface to be detected on the contact detection of the contact head; The target contact pressure is determined based on the fact that the vibration amplitude of the contact point in contact with the road surface to be detected does not exceed a preset vibration amplitude.

[0010] Furthermore, the baseline stability is determined based on the coefficient of variation of the noise floor amplitude of the vibration characteristic signal and a preset threshold, so as to determine the noise floor amplitude fluctuation in the vibration amplitude envelope curve.

[0011] Furthermore, the disease characteristics are determined based on local bulges, pulse-like spikes, and the number of decaying ringing cycles in the vibration amplitude envelope curve, wherein, The local bulges are used to identify areas where the material is not dense, and the pulse spikes and decaying ringing counts are used to identify pits, protrusions, and the stability of the surrounding material.

[0012] Furthermore, the vibration-sensitive component includes, The vibration-sensitive beam has one end embedded in the sensor base and the other end provided with a vibration transmission pin that extends above the contact, so as to amplify the transient jump of the contact into a stable resonant response. A piezoelectric sensing element is disposed on the vibration-sensitive beam to capture the resonant response generated by the vibration-sensitive beam and output vibration characteristic signals.

[0013] Furthermore, the power assembly includes a voice coil motor mover disposed on the sensor base and a voice coil motor stator disposed within the voice coil motor mover, for driving the sensor base to move based on the adjustment command.

[0014] Furthermore, the constant pressure detection component includes a damper housing disposed within the stator of the voice coil motor, and a pressure-sensitive medium and a resistance detection electrode disposed within the damper housing, for detecting changes in DC resistance based on the pressure-sensitive medium's deformation under pressure.

[0015] Furthermore, it also includes a passive constant pressure unit, which includes a main swing arm embedded in the constant pressure detection component, and a follower elastic component disposed at the free end of the main swing arm to provide preload for the main swing arm. Based on the transient jump between the contact and the road surface to be detected that exceeds the adjustment stroke of the constant pressure adjustment unit, it overcomes the preload of the follower elastic component to passively release pressure and avoid collision.

[0016] Furthermore, the passive constant pressure unit also includes an overshoot sensing component, which includes an infrared transmitter and an infrared receiver to form an optical path across the main swing arm's motion plane to identify the swing angle of the main swing arm when it performs a passive pressure relief and avoidance action.

[0017] Furthermore, the stability analysis module extracts a defect-free segment from the vibration amplitude envelope curve as a noise floor window, and the length of the noise floor window corresponds to the signal range collected by the contact rolling a preset distance on the road surface. The disease-free characteristic section refers to a continuous area where the amplitude is always below the preset noise threshold and no pulse-like spikes appear.

[0018] Compared with existing technologies, the advantages of this invention lie in its ability to achieve pressure pre-adjustment before contact by visual acquisition and feature extraction, overcoming the inherent lag in detection response. It utilizes vibration sensing and envelope curve analysis to identify internal material defects such as material looseness and microcracks, achieving a shift from passive detection to proactive early warning. Combined with baseline stability judgment and a pressure compensation module to dynamically correct contact pressure, it ensures a high signal-to-noise ratio for vibration signals. Furthermore, the elastic oscillation of the passive constant pressure unit relieves pressure and avoids overtravel impacts, protecting the detection components. Therefore, this invention achieves visual feedforward pre-calibration, internal material defect perception, and adaptive correction, significantly improving inspection accuracy and reliability.

[0019] Furthermore, based on the extraction and analysis of texture features of the road surface image to be detected, the texture roughness is determined, so that the target contact pressure can be quantitatively set according to the actual roughness of the road surface, and the contact jump amplitude is constrained to not exceed the preset jump amplitude, thereby avoiding contact pressure mismatch caused by changes in road surface roughness and ensuring the adaptability and stability of the detection process.

[0020] Furthermore, baseline stability is determined based on the coefficient of variation of the noise amplitude of the vibration characteristic signal and a preset threshold. By quantifying the vibration reference fluctuation range of normal road surface, a clear trigger criterion is provided for pressure compensation, avoiding false compensation caused by fluctuations in road surface texture roughness, and improving the accuracy and robustness of the compensation logic.

[0021] Furthermore, by determining the characteristics of defects based on local bulges, pulse peaks, and the number of decaying rings in the vibration amplitude envelope curve, it is possible to accurately distinguish between non-dense areas, pits, protrusions, and the stability of the surrounding material, thereby enabling the identification of the type and severity assessment of internal material defects and improving the precision of the detection.

[0022] Furthermore, a vibration-sensitive beam with one end embedded in the sensor base and a vibration transmission pin extending above the contact are adopted. The inherent resonant frequency of the vibration-sensitive beam is used to amplify the transient jump of the contact into a stable resonant response, which effectively improves the signal-to-noise ratio and sensitivity of the vibration signal. The piezoelectric sensing element directly outputs the charge signal, which has a fast response and a compact structure.

[0023] Furthermore, by employing a voice coil motor mover and a voice coil motor stator mounted on the sensor base, the sensor base is directly driven to move based on the magnetic field effect, eliminating the backlash and hysteresis of traditional mechanical transmission and achieving high-precision and high-dynamic response adjustment of contact pressure.

[0024] Furthermore, a damper housing is installed inside the stator of the voice coil motor, along with a pressure-sensitive medium and resistance detection electrodes within the damper housing. The deformation of the pressure-sensitive medium under pressure is directly converted into a change in DC resistance. This results in a short signal transmission path, strong anti-interference capability, and suitability for continuous high-frequency vibration environments under high-speed vehicle operation.

[0025] Furthermore, by using the main swing arm embedded in the constant pressure detection component and the follower elastic component located at the free end of the main swing arm, when the contact encounters a severe impact exceeding the adjustment stroke of the constant pressure adjustment unit, the main swing arm overcomes the preload of the follower elastic component to generate elastic swing, thereby passively releasing pressure and avoiding impact. Its purely mechanical structure has a higher response speed than the electronic control circuit, provides high reliability protection for the detection components with no power consumption, and extends the service life of the device.

[0026] Furthermore, by forming an optical path across the plane of motion of the main swing arm through the infrared transmitter and receiver, the swing angle of the main swing arm performing passive pressure relief and avoidance actions can be detected in real time. When serious road surface abnormalities occur, an overrun signal can be output in a timely manner, providing an independent and highly reliable macroscopic fault trigger signal for the vibration measurement device.

[0027] Furthermore, a defect-free segment is extracted from the vibration amplitude envelope curve as a noise floor window, and the defect-free segment is defined as a continuous region where the amplitude is always below the preset noise threshold and no pulse-like spikes appear. The length of the noise floor window corresponds to the signal range collected by the preset contact rolling distance. This ensures the reliability of the coefficient of variation calculation benchmark, avoids interference from defect signals on baseline stability determination, and further improves the accuracy of pressure compensation. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the vibration measuring device for disease detection according to an embodiment of the present invention. Figure 1 ; Figure 2 This is a schematic diagram of the vibration measuring device described in an embodiment of the present invention. Figure 2 ; Figure 3 This is a schematic diagram of the structure of the vibration measuring device hidden in the vehicle beam according to an embodiment of the present invention; Figure 4 This is a schematic diagram of the constant pressure regulating unit described in an embodiment of the present invention; Figure 5 This is a cross-sectional view of the constant pressure regulating unit described in an embodiment of the present invention. Figure 1 ; Figure 6 This is a cross-sectional view of the constant pressure regulating unit described in an embodiment of the present invention. Figure 2 ; Figure 7 This is a cross-sectional view of the vibration sensing unit described in an embodiment of the present invention. Detailed Implementation

[0029] To make the objectives and advantages of the present invention clearer, the present invention will be further described below with reference to embodiments; it should be understood that the specific embodiments described herein are merely for explaining the present invention and are not intended to limit the present invention.

[0030] Preferred embodiments of the present invention will now be described with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0031] It should be noted that in the description of this invention, the terms "upper", "lower", "left", "right", "inner", "outer", etc., which indicate directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings. This is only for the convenience of description and is not intended to indicate or imply that the device or element must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of this invention.

[0032] Furthermore, it should be noted that, in the description of this invention, 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 can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0033] Please see Figures 1 to 2 As shown, Figure 1 This is a schematic diagram of the road surface defect inspection device described in this invention. Figure 1 ; Figure 2 This is a schematic diagram of the road surface defect inspection device described in this invention. Figure 2 .

[0034] The vibration measuring device for disease detection according to embodiments of the present invention includes: The vibration sensing unit 300 includes a sensor base 301, a contact 302 embedded in the sensor base 301, and a vibration-sensitive component embedded in the sensor base 301 and capable of contacting the contact 302. Based on the contact state between the contact 302 and the road surface to be detected, the vibration-sensitive component converts the transient vibration of the contact 302 caused by the abnormal structure of the road surface material into a resonant response and outputs a vibration characteristic signal. The constant pressure regulating unit 200 includes a power component 201 disposed at the end of the sensor base 301 away from the contact 302, and a constant pressure detection component 202 embedded in the power component 201. The power component 201 drives the sensor base 301 to move axially based on the deviation between the real-time pressure signal output by the constant pressure detection component 202 and the target pressure value, thereby modulating the contact pressure between the contact 302 and the road surface to be tested. The visual acquisition unit 400 includes a camera 402, which is used to continuously capture images of the road surface to be detected within a preset distance in front of the vibration sensing unit 300. The passive constant pressure unit 203 includes a main swing arm 203b disposed at the end of the constant pressure detection component 202 away from the contact 302, and a follower elastic component disposed at the end of the main swing arm 203b. Based on the transient jump between the vibration sensing unit 300 and the road surface exceeding the adjustment stroke of the constant pressure adjustment unit 200, the main swing arm 203b overcomes the preload of the follower elastic component to generate elastic swing for passive pressure relief and avoidance. Pressure control unit 500, which includes: The feature extraction module is connected to the visual acquisition unit 400 and the constant pressure adjustment unit 200 respectively. It is used to extract the texture features in the image of the road surface to be detected and determine the texture roughness of the road surface to be detected, so as to generate a feedforward adjustment command and determine the initial target contact pressure of the constant pressure adjustment unit 200 before the contact 302 contacts the road surface to be detected. The feature analysis module is connected to the vibration sensing unit 300 and the constant pressure regulating unit 200 respectively, and is used to draw the vibration amplitude envelope curve of the road surface to be tested based on the vibration feature signal output by the vibration sensing component, so as to analyze the damage characteristics of the road surface to be tested. A stability analysis module, connected to the feature analysis module, determines the baseline stability of the vibration characteristic signal output by the vibration-sensitive component based on the analysis of the vibration amplitude envelope curve. The pressure compensation module is connected to the stability analysis module and the constant pressure adjustment unit 200 respectively, and is used to compensate the target contact pressure between the vibration sensing unit 300 and the road surface to be detected by the power component 201 based on the baseline stability.

[0035] Specifically, this embodiment determines the initial target contact pressure between the vibration sensing unit 300 and the road surface to be inspected based on the texture roughness of the road surface to be photographed. It then uses a vibration-sensitive component to convert the transient vibration of the contact 302 caused by abnormal road material structure into a resonant response. This resonant response is analyzed, and a vibration amplitude envelope curve is plotted. When the baseline stability in the vibration amplitude envelope curve fluctuates, the pressure compensation module dynamically compensates for the contact pressure between the contact 302 and the road surface to be inspected based on the baseline offset determined by the stability analysis module. This ensures that the vibration characteristic signal maintains a high signal-to-noise ratio, improving the early identification capability of internal material defects such as material looseness and microcracks. This achieves visual feedforward-based contact pressure pre-calibration, vibration response-based perception of internal material defects, and pressure fluctuation feedback-based adaptive correction. This improves the contact continuity between the contact 302 and the road surface to be inspected during contact-based inspection, thereby enhancing detection accuracy.

[0036] In this embodiment of the invention, the texture roughness is determined by extracting and analyzing the texture features of the road surface image to be detected, so as to determine the degree of influence of the texture roughness of the road surface to be detected on the contact detection of the contact 302. The feedforward adjustment command, which is determined based on the texture roughness and texture roughness range, is used to change the driving current of the power component 201 so that the contact 302's bounce amplitude relative to the road surface to be detected is not greater than the preset bounce amplitude. The jump amplitude is the peak value of the vertical displacement of the contact 302 relative to the sensor base 301 caused by the uneven road surface. The initial target contact pressure is determined based on the amplitude of the bounce between the contact 302 and the road surface to be tested, so as to keep the contact state between the road surface to be tested and the contact 302 constant.

[0037] Please see Figures 4 to 6 As shown, Figure 4 This is a schematic diagram of the constant pressure regulating unit described in this invention; Figure 5 A cross-sectional view of the constant pressure regulating unit described in this invention. Figure 1 ; Figure 6 A cross-sectional view of the constant pressure regulating unit described in this invention. Figure 2 .

[0038] In this embodiment of the invention, the constant pressure detection component 202 includes a damper housing 202a, a pressure-sensitive medium 202b, and resistance detection electrodes 202c. The damper housing 202a is a sealed cylindrical cavity, the lower end of which is fixed to the sensor base 301. The cavity is filled with the pressure-sensitive medium 202b. The lower end of the main swing arm 203b extends into the inner cavity of the damper housing 202a as a pressure-bearing end and contacts the pressure-sensitive medium 202b. The resistance detection electrodes 202c are arranged in pairs on the inner wall of the damper housing 202a and / or the extended end of the main swing arm 203b, for real-time detection of the DC resistance change of the pressure-sensitive medium 202b caused by the pressure deformation of the contact 302 in contact with the road surface to be tested, so as to generate a feedback signal characterizing the current contact pressure for constant pressure regulation.

[0039] The power assembly 201 includes a voice coil motor mover 201b disposed on the outer wall of the damper housing 202a, and a voice coil motor stator 201a disposed inside the voice coil motor mover 201b. The voice coil motor stator 201a is an annular permanent magnet embedded in the damper housing 202a. The voice coil motor mover 201b is a coil frame and a coil winding wound on the coil frame. The voice coil motor mover 201b is slidably sleeved within the magnetic field area of ​​the voice coil motor stator 201a, so as to drive the sensor base 301 to move linearly back and forth based on the magnetic field effect between the mover and the stator, thereby driving the contact 302 to move axially.

[0040] In this embodiment of the invention, the texture features of the captured image of the road surface to be detected are extracted to determine the texture roughness of the road surface to be detected. If the texture roughness exceeds the texture roughness range, the output is sent to the power component to drive the sensor base 301 to perform axial displacement, thereby driving the contact 302 to perform axial displacement feedforward adjustment command so that the contact reaches the initial target contact pressure with a jump amplitude not greater than the preset jump amplitude.

[0041] Specifically, by determining the initial target contact pressure before the contactor 302 contacts the defect, the hysteresis of the passive response after contact is overcome, the contact pressure between the vibration sensing unit 300 and the road surface to be tested is kept constant, the detection accuracy of road defects is improved, and thus the detection efficiency is improved. Optionally, the pressure-sensitive medium 202b may be a liquid metal that reflects pressure through changes in resistance, or it may be other types of smart materials. Correspondingly, the resistance detection electrode 202c may be replaced with a sensor that can detect changes in the corresponding electrical parameters.

[0042] Optionally, an axial limiting rod 201b-1 is provided on the end face of the voice coil motor mover 201b near the main swing arm 203b, and a stop ring 201b-2 adapted to the axial limiting rod 201b-1 is provided on the outer side of the main swing arm 203b to limit the stroke of the voice coil motor mover 201b and prevent it from leaving the magnetic field range of the voice coil motor stator 201a.

[0043] Optionally, the voice coil motor mover 201b has the same outer diameter as the sensor base 301, so as to prevent the sensor base 301 and / or the voice coil motor stator 201a from getting stuck with the road surface defect when the contact 302 encounters a road surface defect that exceeds the adjustment stroke of the constant pressure adjustment unit 200, and to ensure that the avoidance compensation action of the passive constant pressure unit 203 is smooth.

[0044] In this embodiment of the invention, when the texture roughness exceeds the normal texture roughness range of cement / asphalt pavement, the initial target contact pressure is the contact pressure with the constraint that the jump amplitude of the contact 302 is not greater than the preset jump amplitude. The preferred value of the preset jump amplitude is 0.05mm to 0.15mm, which is set according to the pavement type and detection accuracy requirements.

[0045] Optionally, the texture roughness is determined based on the gray-level co-occurrence matrix analysis of the road surface image to be detected. By calculating the contrast, energy, entropy and correlation parameters in the gray-level co-occurrence matrix, the fine texture level of the road surface is quantified. Alternatively, the texture features of the image are extracted based on the local binary mode algorithm, and the histogram distribution of the frequency of each mode is statistically analyzed to characterize the roughness of the road surface.

[0046] In an optional implementation of this embodiment, the visual acquisition unit 400 continuously captures images of the road surface to be detected within a preset distance in front of the vibration sensing unit 300. This may include an industrial area array camera, an adjustment frame 401 mounted on the front beam 101 or rear beam 101 of the inspection vehicle to adjust the position and angle of the industrial area array camera, and a supplementary lighting module 403 mounted on the adjustment frame 401 to provide supplementary lighting for the industrial area array camera.

[0047] In this embodiment of the invention, the vibration amplitude envelope curve is obtained by performing a Hilbert transform on the resonant response signal output by the vibration-sensitive component, extracting the instantaneous amplitude, and performing a sliding window root mean square calculation on the amplitude to obtain the vibration amplitude envelope curve that varies with the detection position. The road surface defects are identified by analyzing the vibration amplitude envelope curve to obtain defect characteristics. Local bulges in the vibration amplitude envelope curve are used to identify areas of non-dense material, and pulse-like spikes and decaying ringing counts in the vibration amplitude envelope curve are used to identify potholes, protrusions, and the stability of surrounding materials.

[0048] Please see Figure 7 As shown, Figure 7 This is a cross-sectional view of the vibration sensing unit described in this invention.

[0049] The vibration-sensitive component includes a vibration-sensitive beam 303 with one end embedded in the sensor base 301, a vibration transmission pin 303b disposed at the free end of the vibration-sensitive beam 303 and extending above the contact 302, and a piezoelectric sensing element 303c disposed on the surface of the vibration-sensitive beam 303 near the fixed end. The vibration-sensitive beam 303 captures the bouncing of the contact 302 rolling on the road surface to be detected based on the vibration transmission pin 303b at its end. The piezoelectric sensing element 303c converts the resonant deformation of the vibration-sensitive beam 303 into an output charge signal. In this embodiment of the invention, a sliding window scan is performed on the vibration amplitude envelope curve to extract the amplitude distribution characteristics within the window. When a local bulge with a amplitude significantly higher than the surrounding area and a certain width appears in the curve, it is determined that there is a material non-dense or loose defect in that area. When a pulse-like peak with a sharp rise and rapid fall in amplitude appears in the curve, it is determined that there is a geometric boundary of a pit or protrusion. In the attenuation section after the pulse-like peak, if the vibration amplitude shows an oscillating attenuation pattern that fluctuates repeatedly and fails to recover to the baseline level for a long time, it is determined that the material properties around the pit or protrusion are unstable and there is a risk of continued expansion and deterioration.

[0050] Specifically, when the road surface material has internal anomalies such as non-compactness, microcracks, and shallow voids, the contact 302 generates a transient vibration corresponding to the structural state. The vibration-sensitive component converts this transient vibration into a resonant response and outputs a vibration characteristic signal, converting the mechanical vibration of the contact 302 into a quantifiable electrical signal. This provides raw data for subsequent feature analysis, enabling the device to sense internal defects in the material that have not yet formed macroscopic defects. This improves the ability to identify early-stage defects and realizes the transformation from passively discovering existing defects to actively warning of potential defects, thus enhancing the ability to perceive internal defects in the material.

[0051] Optionally, the sensor base 301 is provided with a hemispherical recess for accommodating the contact 302. The hemispherical recess is provided with a mounting groove 303a for accommodating one end of the vibration-sensitive beam 303. The vibration-sensitive beam 303 is a metal cantilever beam with an inherent resonant frequency. The contact 302 is made of ceramic or metal material with high hardness, high wear resistance and good rolling characteristics, and is freely rolled and embedded in the hemispherical recess.

[0052] Specifically, the hemispherical groove on the sensor base 301 allows the contact 302 to roll freely in multiple directions, ensuring sensitive tracking of micro-undulations in the road surface; the vibration-sensitive beam 303 is a metal cantilever beam with an inherent resonant frequency, which can amplify the transient jump of the contact 302 into a stable resonant response at a specific frequency and improve the signal-to-noise ratio; the contact 302 is made of high-hardness ceramic or metal material, ensuring wear resistance and deformation transmission accuracy under high-speed rolling; the overall structure is compact and has no additional transmission gap, enabling it to work stably in long-term high-frequency vibration environments, providing highly consistent and repeatable original vibration signals for subsequent feature analysis.

[0053] Optionally, the contact 302 can be made of silicon nitride ceramic beads, and the piezoelectric sensing element 303c can be made of PVDF piezoelectric film or piezoelectric ceramic sheet. When the contact bead rolls over a road surface in a normal and uniform state, it generates a wide-frequency, low-amplitude steady-state vibration signal similar to white noise. When it rolls over loose road surface material, the edge of micro-cracks, or shallow voids, the silicon nitride ceramic contact bead undergoes a transient jump or abrupt change in damping characteristics. This is transmitted to the free end of the vibration-sensitive beam 303 via the vibration transmission pin 303b, which excites a characteristic resonant response near the natural frequency.

[0054] Optionally, the aforementioned curve is not limited to the vibration amplitude envelope. It can also perform Fourier transform on the original vibration signal to plot the spectral centroid shift curve or the energy proportion curve of a specific frequency band as the position changes. By analyzing the migration of vibration energy in different frequency bands, the structural stiffness changes caused by voiding and crack development can be identified. The corresponding analysis algorithms and threshold systems are also updated to adapt to the signal characteristics of different types of sensors.

[0055] In this embodiment of the invention, the baseline stability is determined based on the coefficient of variation of the noise floor amplitude and a preset threshold, and is used to determine the noise floor amplitude fluctuation of the vibration amplitude envelope curve. The coefficient of variation is based on the calculation of the standard deviation and mean of the amplitude sequence within the window by taking a segment without disease characteristics from the vibration amplitude envelope curve as the noise floor window, and using the ratio of the standard deviation to the mean as the coefficient of variation. The preset threshold is based on the constant pressure unit running stably on a flat and uniform standard road surface at the target pressure, continuously collecting vibration characteristic signals and calculating the coefficient of variation, repeating the experiment no less than 10 times, and taking the average value of the coefficient of variation plus 1.5 times the standard deviation as the preset threshold. In this embodiment of the invention, the coefficient of variation of the noise floor amplitude in the vibration amplitude envelope curve is used as a quantitative indicator. When the coefficient of variation is less than a preset threshold, the baseline is determined to be stable. When the coefficient of variation is greater than or equal to the preset threshold, the noise floor amplitude fluctuation is determined to exist, and the pressure compensation module is triggered to output a compensation command.

[0056] Specifically, the length of the noise floor window corresponds to the signal range collected by the contact 302 rolling a preset distance on the road surface. The defect-free feature section refers to a continuous area where the amplitude is always lower than the preset noise threshold and no pulse-like spikes appear. The preset noise threshold is obtained by statistically analyzing the vibration signals collected from normal road surfaces. In this embodiment, it is preferably twice the root mean square value of the normal signal. Optionally, when the constant pressure regulating unit 200 is running stably at the optimal target pressure on a flat and uniform normal asphalt or cement road surface, the coefficient of variation of the noise floor amplitude of the vibration amplitude envelope curve is usually between 0.02 and 0.05. The preset threshold can be set to 0.06 to 0.10, and the specific value is determined according to the actual results of the calibration experiment.

[0057] Alternatively, baseline stability can also be quantified using root mean square error or peak factor, with the corresponding preset thresholds obtained through the same calibration experiment.

[0058] In this embodiment of the invention, the passive constant pressure unit includes a vertical plate 203a, and a main swing arm 203b is rotatably mounted on the vertical plate 203a via a hinge shaft 203c. A torsion spring 203d for providing preload is fitted on the hinge shaft 203c to continuously apply a torsional torque toward the road surface to be tested to the main swing arm 203b. Specifically, the main swing arm 203b overcomes the elastic swing generated by the preload force, driving the constant pressure adjustment unit 200 and the vibration sensing unit 300 to move, so as to avoid defects on the road surface to be tested that exceed the adjustment stroke of the constant pressure adjustment unit 200. Based on the elastic swing and reset of the mechanical mechanism, it provides power-free and highly reliable protection for the detection components and extends the service life of the device.

[0059] Alternatively, the follow-up elastic component can also be implemented using other elastic elements. For example, a preloaded spring that provides tension can be used instead of the torsion spring 203d, or the main swing arm 203b itself can be designed as a flexible arm made of elastic material, utilizing the bending and rebound characteristics of the material itself to achieve passive absorption and reset of the impact. Optionally, the passive constant pressure unit 203 further includes an over-position sensing component 203e, which includes an infrared transmitter and an infrared receiver, respectively fixed at relative positions on both sides of the swing path of the main swing arm 203b, forming an infrared light path spanning the motion plane of the main swing arm 203b. When the main swing arm 203b swings due to severe road surface anomalies and its swing angle exceeds a preset over-position angle threshold, the over-position angle threshold is calibrated according to the maximum effective adjustment stroke of the constant pressure adjustment unit 200. In this embodiment, it is preferably 15°. A local structure of the main swing arm 203b will enter and block the infrared light path, causing the infrared receiver to be unable to receive the infrared signal. The electrical signal state of the infrared receiver will flip, and an over-position signal will be output to the pressure control unit 500.

[0060] Please see Figure 3 As shown, Figure 3 This is a schematic diagram of the hidden beam structure of the road surface defect inspection device described in this invention.

[0061] In this embodiment of the invention, the vibration measuring device is detachably mounted on the rear of the inspection vehicle via a mounting assembly; The mounting assembly includes a beam 101, a connecting component 102, and a mounting plate 103. The beam 101 is a metal crossbeam extending laterally along the vehicle and fixed to the underside of the rear chassis of the inspection vehicle. The connecting component 102 can be mounted on the beam 101. The mounting plate 103 is fixed to the connecting component 102 and is used to provide an installation reference for the vibration sensing unit 300, the constant pressure regulating unit 200, the passive constant pressure unit 203, the visual acquisition unit 400, and the pressure control unit 500. The connecting assembly includes a C-shaped connecting bracket 102a and a locking bolt 102b. The C-shaped connecting bracket 102a has a through hole for the locking bolt 102b to pass through. After the locking bolt 102b is screwed into the C-shaped connecting bracket 102a, its end is pressed against the surface of the vehicle beam 101. Specifically, the connecting component 102 achieves reliable fixation between the connecting component 102 and the vehicle beam 101 through friction, thereby enabling quick assembly and disassembly and stable fixation of the mounting assembly 100.

[0062] The technical solution of the present invention has been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the scope of protection of the present invention.

[0063] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A vibration measuring device for detecting diseases, characterized in that, include, The vibration sensing unit includes a sensor base and a contact, and a vibration-sensitive component disposed between the sensor base and the contact, for outputting a vibration characteristic signal characterizing the transient jump of the contact contacting the road surface to be detected based on the vibration-sensitive component; A visual acquisition unit is used to continuously capture images of the road surface to be detected in front of the vibration sensing unit; The constant pressure regulating unit includes a power component mounted on a sensor base and a constant pressure detection component embedded in the power component, which is used to modulate the contact pressure between the contactor and the road surface to be tested based on the pressure signal output by the constant pressure detection component. The feature extraction module is used to extract the texture roughness of the road surface to be detected in order to generate adjustment instructions and determine the target contact pressure of the constant pressure adjustment unit before the contactor contacts the road surface to be detected. The feature analysis module is used to draw a vibration amplitude envelope curve based on the vibration feature signal in order to analyze the damage characteristics of the road surface to be detected. A stability analysis module is used to analyze the vibration amplitude envelope curve to determine the baseline stability of the vibration characteristic signal; A pressure compensation module is used to compensate the power assembly for the target contact pressure between the contactor and the road surface to be detected based on the baseline stability.

2. The vibration measuring device for disease detection according to claim 1, characterized in that, The texture roughness is determined based on the extraction and analysis of texture features of the road surface image to be detected, and is used to characterize the degree of influence of the texture roughness of the road surface to be detected on the contact detection of the contact head. The target contact pressure is determined based on the fact that the vibration amplitude of the contact point in contact with the road surface to be detected does not exceed a preset vibration amplitude.

3. The vibration measuring device for disease detection according to claim 2, characterized in that, The baseline stability is determined based on the coefficient of variation of the noise floor amplitude of the vibration characteristic signal and a preset threshold, so as to determine the noise floor amplitude fluctuation in the vibration amplitude envelope curve.

4. The vibration measuring device for disease detection according to claim 1, characterized in that, The disease characteristics are determined based on local bulges, pulse-like spikes, and the number of decaying ringing cycles in the vibration amplitude envelope curve, wherein... The local bulges are used to identify areas where the material is not dense, and the pulse spikes and decaying ringing counts are used to identify pits, protrusions, and the stability of the surrounding material.

5. The vibration measuring device for disease detection according to claim 4, characterized in that, The vibration-sensitive component includes, The vibration-sensitive beam has one end embedded in the sensor base and the other end provided with a vibration transmission pin that extends above the contact, so as to amplify the transient jump of the contact into a stable resonant response. A piezoelectric sensing element is disposed on the vibration-sensitive beam to capture the resonant response generated by the vibration-sensitive beam and output vibration characteristic signals.

6. The vibration measuring device for disease detection according to claim 1, characterized in that, The power assembly includes a voice coil motor mover disposed on the sensor base and a voice coil motor stator disposed within the voice coil motor mover, for driving the sensor base to move based on the adjustment command.

7. The vibration measuring device for disease detection according to claim 6, characterized in that, The constant pressure detection component includes a damper housing disposed within the stator of the voice coil motor, and a pressure-sensitive medium and a resistance detection electrode disposed within the damper housing, for detecting changes in DC resistance based on the pressure-sensitive medium's deformation under pressure.

8. The vibration measuring device for disease detection according to claim 1, characterized in that, It also includes a passive constant pressure unit, which includes a main swing arm embedded in the constant pressure detection component, and a follower elastic component disposed at the free end of the main swing arm to provide preload to the main swing arm.

9. The vibration measuring device for disease detection according to claim 8, characterized in that, The passive constant pressure unit also includes an overshoot sensing component, which includes an infrared transmitter and an infrared receiver to form an optical path across the main swing arm's motion plane to identify the swing angle of the main swing arm when it performs a passive pressure relief and avoidance action.

10. The vibration measuring device for disease detection according to claim 3, characterized in that, The stability analysis module extracts a defect-free segment from the vibration amplitude envelope curve as a noise floor window. The length of the noise floor window corresponds to the signal range collected by the contactor rolling a preset distance on the road surface. The disease-free characteristic section refers to a continuous area where the amplitude is always below the preset noise threshold and no pulse-like spikes appear.

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