CN110926343A - Absolute measuring device and method for dynamic change parameters of cracks - Google Patents
Absolute measuring device and method for dynamic change parameters of cracks Download PDFInfo
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Abstract
The invention discloses an absolute measuring device and method for dynamic change parameters of a crack, wherein the device comprises a sensor body (9) and two photoelectric targets arranged on two sides of the crack to be measured on a structural body, and a connecting line between the two photoelectric targets is vertical to the trend of the crack; the sensor body comprises a machine shell (7), an optical lens (1) arranged in the machine shell (7), an image sensor (2) and a core control unit (3), wherein the optical lens (1) aims at a photoelectric target, and a narrow-band filter (23) with a position switching function is arranged between the optical lens (1) and the image sensor (2); the transmission wavelength of the narrow-band filter is matched with the emergent wavelength of the photoelectric target. According to the invention, the optical filter is switched in a time-sharing manner, and the opening and closing of the photoelectric target are controlled, so that a first target image of an individual target in the same field of view and a second target image of the whole crack in the field of view are acquired in a time-sharing manner, and thus, the absolute width of the crack in the field of view and the change of the absolute width of the crack along with the time are measured.
Description
Technical Field
The invention belongs to the field of structure measurement, and particularly relates to an absolute measuring device and a crack measuring method for crack measurement and dynamic change parameters of a large-scale structure.
Background
Cracks appear in large-scale infrastructures such as bridges, tunnels, dams and the like under the long-term action of environmental erosion, material aging and load, and are one of the most serious diseases. The cracks may develop further due to the long term effects, causing catastrophic accidents. The change process of the crack is accurately measured in real time and for a long time, and the method has very important significance for safety assessment, healthy operation and prevention and reinforcement of large facilities.
At present, the method adopted for measuring the crack mainly comprises the following steps: the manual regular measurement, the inspection of a monitoring instrument and the installation of a traditional crack meter are carried out for a long time. The monitoring methods have different defects, the manual detection efficiency is low, and the personnel safety has hidden danger. The instrument patrols and examines and obtains and can only acquire data at that time, and measurement accuracy is lower. The traditional crack meter of installation need be connected fixedly at crack both ends and structure thing main part, receives external force when the structure, receives vehicle, dam when receiving water pressure like the bridge, and the structure will take place deformation, and the sensor of fixing on the structure also can warp, causes measurement accuracy to descend. In a field environment, temperature and humidity changes are inevitable factors, and the traditional sensor is deformed due to the thermal instability of the material, so that the measurement accuracy is reduced. The development and change of the crack are related to real-time conditions, the response speed of the traditional sensor is slow, dynamic monitoring data are difficult to obtain, and the change condition of the crack under special conditions cannot be reflected.
With the development of imaging technology and image processing technology of image sensors, various sensors based on image recognition are widely applied in the fields of displacement measurement, structure size detection and the like. Chinese patent No. 201010240543.2, "a method and apparatus for measuring width of tunnel lining crack", discloses a method and apparatus for measuring width of tunnel lining crack, including digital image sensor acquisition crack image, image gray scale conversion, edge extraction, minimum distance calculation, etc., these utilize image recognition to measure structure surface crack, can improve measurement accuracy, response speed, implement non-contact measurement, reduce the influence of external environment, it is an effective means to solve the existing measurement method, but based on image measurement from the principle given is the relative change of crack width, absolute measurement also needs to be carried out a series of calibrations, and the image processing algorithm is complex, the time consuming is long, it is difficult to implement the rapid high-precision absolute measurement of crack change.
Another patent applied by the company, namely a crack dynamic change sensor based on multi-target image processing and a crack measuring method (201811632196.0), discloses a method for setting a plurality of LED targets on two sides of a crack so as to carry out absolute measurement of the width of the crack, so that the absolute measurement of single-point positions on two sides of the crack is realized, the current measuring precision reaches 0.01mm, and the response frequency is 10Hz, but the method has the problems that only the relative change quantity of the crack can be measured, and the absolute width of the crack and the change of the absolute width of the crack along with the time cannot be obtained.
Disclosure of Invention
The invention provides an absolute measuring device and a measuring method for dynamic change parameters of cracks.
The technical scheme of the invention is as follows:
an absolute measuring device of dynamic change parameters of cracks is characterized in that: the photoelectric sensor comprises a sensor body and two photoelectric targets arranged on two sides of a crack to be detected on a structural body, wherein a connecting line between the two photoelectric targets is vertical to the trend of the crack; the sensor body comprises a shell, an optical lens, an image sensor and a core control unit, wherein the optical lens, the image sensor and the core control unit are arranged in the shell; the transmission wavelength of the narrow-band filter is matched with the emergent wavelength of the photoelectric target;
a switching structure is arranged on the casing and drives the narrow-band filter to realize position switching; the core control unit controls the switch and the switching structure of the photoelectric target, so that the image sensor obtains a first target image when the narrow-band filter is positioned in front of the image sensor and the photoelectric target is opened and a second target image when the narrow-band filter is not positioned in front of the image sensor and the photoelectric target is closed in a time-sharing manner, and then the dynamic change value of the absolute width of the crack in the target view field is calculated.
In the absolute measuring device for the crack dynamic change parameters, the switching mechanism is composed of an electromagnet and a mounting substrate, the electromagnet comprises an electromagnetic coil, a spring and an armature, the electromagnetic coil drives the armature to stretch and retract so as to drive the mounting substrate to switch positions, and the narrow-band filter is fixed on the mounting substrate.
In the absolute measuring device for the dynamic change parameters of the crack, the narrow-band filter and the substrate transmitting the broad spectrum are arranged on the mounting substrate, and when the second target image is obtained, the substrate is positioned between the image sensor and the optical lens.
In the absolute measuring device for the dynamic change parameters of the cracks, the sensor body further comprises a remote communication unit, and the remote communication unit transmits the processing result to a remote data center under the control of the core control unit.
In the absolute measuring device for the dynamic change parameters of the crack, the sensor body further comprises a power management unit, and the switch of the photoelectric target and the power-on and power-off of the electromagnetic coil are realized under the control of the core control unit.
In the absolute measuring device for the dynamic change parameters of the cracks, the white light lamp is arranged at one end, close to the structure body, of the machine shell, so that the target illumination is realized.
In the absolute measuring device for the dynamic change parameters of the crack, the target is an LED lamp or a light emitting diode, and the output spectrum of the LED lamp or the light emitting diode is a near-infrared band.
In the absolute measuring device for the dynamic change parameters of the crack, the casing is fixed on the surface of the structure body on one side of the slit through the fixing support, and the fixing support is provided with the strip hole for fixing the sensor body, so that the distance between the optical lens and the target is adjusted.
An absolute measurement method of dynamic change parameters of a crack comprises the following steps:
【1】 Presetting parameters;
【2】 The measuring device switches to the second target imaging mode: the photoelectric target is turned off and the narrowband filter is not in front of the image sensor;
【3】 Reading the 1 st frame of image data and carrying out image processing;
【4】 Acquiring position coordinates of corresponding pixel points of two edges of the crack on the image sensor;
【5】 The measuring device switches to the first target imaging mode: the photoelectric target is opened and the narrowband filter is positioned in front of the image sensor;
【6】 Reading the 2 nd frame image data, and performing image processing;
【7】 Calculating to obtain the coordinates of the central position of the light spot of the target, and determining a crack measuring line and the position of the crack measuring line at the pixel point of the image sensor;
【8】 Comparing with the 1 st frame image to obtain the pixel coordinate position of the intersection point of the crack measuring line and the crack edge;
【9】 Obtaining an absolute width value of the crack according to the target distance, the target and the pixel coordinate position of the intersection point;
【10】 And (5) repeating the steps (5) to (9) to obtain the absolute width value of the crack of 2 to n frames, namely the dynamic change value of the absolute width of the crack.
In the absolute measuring method for the dynamic change parameters of the cracks, the steps (1) to (10) are repeated after a set period of time at intervals.
The invention has the following technical effects:
1. according to the invention, the first target image of the single target in the same field of view and the second target image of the whole crack in the field of view are obtained in a time-sharing manner by switching the optical filter in a time-sharing manner and controlling the opening and closing of the photoelectric target, the absolute dynamic change value of the target distance in the first target image is used as the absolute calibration of the relative value of the crack width in the second target image, and the conditions and parameters of secondary optical imaging are kept consistent, so that the absolute width of the crack in the field of view and the change of the absolute width of the crack along with the time are measured. After a plurality of frames of first target images are spaced, one frame of second target image is obtained for data fusion processing, and the time resolution and sufficient accuracy of the whole system are ensured. The device has the characteristics of compact structure, easiness in installation, good stability, high measurement precision, quick time response and the like, and is suitable for real-time online accurate measurement of the surface crack of the structure.
2. When the first target image is obtained, two photoelectric targets are respectively arranged on two sides of the crack, the width of the measured crack is equivalently replaced by measuring the distance of the set target, the dynamic change parameter of the crack is obtained, and the method has the characteristics of high measurement precision, quick time response and the like. When the photoelectric target is started, the optical signal of the image sensor is filtered by matching with the narrow-band filter, so that the influence of external background light on the background signal and the measurement result of the image sensor is overcome, and the dynamic range of the measurement signal is improved.
3. When the second target image is obtained, the narrow-band optical filter is switched to the substrate which can transmit the broad spectrum when the photoelectric target is closed, so that the influence of the thickness of the substrate on which the film coating of the narrow-band optical filter is positioned on the image distortion is compensated, and the front-back consistency of the first target image and the second target image is ensured. Meanwhile, the white light lamp for compensating illumination is arranged at one end of the shell, so that clear crack images can be obtained at daytime and night, and the measurement accuracy of cracks is ensured.
4. The invention adopts the remote communication unit module, can realize the remote control of the sensor, the data is transmitted to the data center through the 4G wireless network or the broadband limited network, can work all weather under the unattended condition of the field environment, realize the remote systematic management; meanwhile, a core control unit and a storage processing unit are developed based on the DSP and the ARM system, so that the whole system is compact in structure, stable and reliable in performance and suitable for long-term remote online measurement.
Drawings
FIG. 1 is a schematic diagram of the composition of the crack measuring device of the present invention;
FIG. 2 is a schematic diagram of a crack measuring device with a fill light in an embodiment;
FIG. 3 is a schematic diagram of the sensor circuit module of the present invention;
FIG. 4 is a schematic diagram of a second target image captured by the image sensor according to the present invention;
FIG. 5 is a schematic diagram of a first target image captured by an image sensor according to the present invention;
FIG. 6 is a schematic view of the fixing structure of the fixing bracket and the sensor body according to the present invention;
FIG. 7 is a schematic view of the switching mechanism of the present invention;
FIG. 8 is a schematic view of the switching mechanism of the present invention with the armature extended;
FIG. 9 is a schematic view of the switching mechanism of the present invention during retraction of the armature;
FIG. 10 is a flow chart of the measurement and calculation of the absolute width of the crack and its dynamic variation according to the present invention.
The reference numbers are as follows: 1-an optical lens; 2-an image sensor; 3-a core control unit; 4-processing the storage unit; 5-a power management unit; 6-a remote communication unit; 7, a machine shell; 9-a sensor body; 10-cracking; 11-a structure; 12 — a target base; 13-a fixed support; 15-field of view area; 16-elongated holes; 20-a switching mechanism; 21-an electromagnetic coil; 22-an armature; 23-narrow band filter; 24-a substrate; 25-a mounting substrate; 26-a spring; 30-white light lamp; 81 — first target; 82-second target.
Detailed Description
As shown in fig. 1 to 3, the sensor for rapidly measuring dynamic changes of cracks of the present invention includes a sensor body 9, two photoelectric targets, a first target 81 and a second target 82, which are disposed on two sides of a crack to be measured on a structure. The connecting line between the two photoelectric targets is vertical to the trend of the crack; the sensor body 9 comprises a casing 7, and an optical lens 1, an image sensor 2 and a core control unit 3 which are arranged inside the casing 8, wherein the optical lens 1 aims at a photoelectric target, which is the basic composition of the existing crack measuring system.
The invention is characterized in that a narrow-band filter 23 for switching positions is arranged between the optical lens 1 and the image sensor 2; the transmission wavelength of the narrow-band filter is matched with the emergent wavelength of the photoelectric target, and the narrow-band filter is used for filtering background light when working sunlight irradiates in the daytime, reducing the background signal of the image sensor 2 and ensuring the dynamic range of the signal.
In fig. 1 and 2, a switching structure 20 is installed on the casing 8 to drive a narrow-band filter 23 to realize position switching and filtering of background light. The core control unit 3 controls the switch and switching structure 20 of the photoelectric target, so that the image sensor 2 obtains a first target image when the narrowband filter 23 is in place and the photoelectric target is turned on and a second target image when the narrowband filter 23 is not in place and the photoelectric target is turned off in a time-sharing manner, and the first target image obtains a dynamic change absolute parameter at the specific point position of the crack by processing the real-time position absolute value of the target lamp; the second target image acquires an image of the whole crack in the view field, the position of a pixel point of the crack edge in the image sensor is obtained through a conventional image processing algorithm, the absolute width value of the crack in the target view field is obtained through calculation through data fusion processing of the first target image and the second target image, and the absolute width parameter of the crack changes along with time, namely the absolute value of dynamic change is obtained through processing calculation of a plurality of frames of images. Because the time for processing the second target image is long, one frame of the second target image is obtained for data fusion processing after a plurality of frames of the first target image are adopted at intervals, and the time resolution of the whole system is ensured.
Fig. 2 shows a specific embodiment, a white light lamp 30 is disposed at one end of the housing 8 close to the structural body 11 to implement illumination of the target, which aims to supplement light at night or when the sunlight brightness is insufficient, so as to obtain a clear second target image, at which time the photoelectric target is turned off, and the image sensor captures an image of the crack. The white light is used for supplementing light, the white light is used as a wide-spectrum light source, clear color crack images can be obtained after the light is supplemented, if the narrow-spectrum LED light is used for supplementing light, chromaticity deviation of the images (similar to color cast images captured by an infrared camera at night) can occur, the crack images are not clear enough, and the processing precision and the measurement result are not good.
In fig. 3, the sensor circuit module includes an image sensor 2, a core control unit 3, a processing storage unit 4, a power management unit 5, and a remote communication unit 6. The image sensor 2 adopts a CMOS or CCD sensor, the pixel resolution is selected according to a measurement target, and the sensor has a large measurement range and high measurement precision. The core control unit 3 controls the image sensor 2 to collect images of the targets and the cracks, the data are stored in the processing and storing unit 4, the processing and storing unit 4 processes the images to obtain distance change values between the targets or crack images, and local display is carried out or processing results are transmitted to a remote data center through the remote communication unit 6 to directly display crack parameters; or according to the field implementation condition, the core control unit 3 directly transmits the acquired image data to a remote data center through the remote communication unit 6, and then performs image processing, calibration and calculation and display of dynamic parameters of the crack.
The core control unit 3 is a core unit of the image recognition crack sensor, is constructed by a DSP and an ARM processor, comprises a sensor triggering and timing control module, an image data acquisition module and is used for controlling storage processing of images, implementation of remote instructions and data transmission, and has the advantages of high integration level, compact structure, high operation efficiency, stability and reliability, so that the sensor has the characteristic of quick time response.
The processing and storing unit 4 stores the image acquired by the image sensor 2 in a Flash memory under the control of the core control unit 3, reads each frame of light spot image data in the memory through a 32-bit ARM processor, identifies the center position or the crack edge of a target after carrying out graying processing on the image, and finally calculates the dynamic change parameter of the crack width.
The remote communication unit 6 is used for transmitting images and data and receiving remote control instructions. The remote communication unit 6 receives a remote control instruction through a 4G mobile network or a wired broadband network, and transmits processed data to a remote data center to realize remote measurement in an unattended field environment.
The power management unit 5 is used for power supply control of the image sensor 2, the core control unit 3, the processing storage unit 4, the remote communication unit 6, and the peripheral device electromagnetic coils 21, the first target 81, the second target 82, and the white light lamp 30. The power management unit 6 can be controlled by the instruction of the remote communication unit 6, and the power supply of each power-on unit is set and distributed according to the measurement time requirement, so that the power consumption of the sensor is reduced.
Fig. 4 and 5 respectively show a view imaging schematic diagram of an image sensor when a second target image and a first target image are obtained, in a second target imaging mode, the photoelectric target is closed, before the substrate 24 is switched to the image sensor 2 by the switching structure 20, an image of the whole crack and a shell image of the target are imaged in the view of the image sensor at this time, a clear crack image is obtained through white light supplement if necessary, and then the pixel point position of the crack edge on the image sensor is obtained according to a conventional image algorithm.
In the first target imaging mode, the photoelectric target is powered on, and the switching structure 20 filters the background light before the narrowband filter 23 is switched to the image sensor 2, because the brightness of the target is high, only the image of the target is displayed on the image sensor and the image of the crack cannot be displayed through gain adjustment and threshold processing, the image processing and calculation obtain the position change between the targets, and because the distance between the two installed targets is known, the distance is the absolute value of the specific position of the crack.
In fig. 4 and 5, a and B are the centroid positions of two targets, AB is a crack measurement line, and C and D are the intersection point positions of the connection line of the two points AB and the edge of the crack, when the targets are installed, the connection line of the points AB and the direction of the crack are made to be substantially perpendicular as much as possible, and the position where the change of the crack width is slow is selected as much as possible to set the targets, so that the change between CDs can represent the change of the crack width in a small region of the target view field. Since the change of the crack on the large structure is expressed as the expansion and contraction of the crack, the change value of the distance between the AB is equivalent to the change value of the distance between the CDs, and since the position of the A, B two points can be accurately measured and is a known parameter, the absolute distance between the CDs can be obtained at the pixel position of the image sensor through the A, B, C, D point. If the absolute change value between the CDs is fused into the image of the whole crack, and the absolute width change of the whole crack in the view field can be obtained through the analysis and calculation of a plurality of frames of images.
The photoelectric target adopts a luminous tube or an infrared LED with the output spectrum of near-infrared band, preferably an LED with the wavelength of 850nm, the center wavelength of the narrow-band filter is 850nm, and the half width is 20-50 nm. The narrow-band filter is formed by optically coating a glass substrate, and the thickness of the glass substrate in actual image processing can generate certain refraction influence on an image, so that slight image distortion is caused. In order to keep consistency of the first target image and the second target image, when the second target image is acquired, the narrow-band optical filter is switched to the substrate which can transmit a broad spectrum while the photoelectric target is closed, and the thickness and the material of the substrate are kept consistent, namely the glass substrate which is not plated with the narrow-band optical film.
As shown in fig. 6, after the target is installed, the feet of the fixing support 13 are installed on one side of the crack 10, and the fixing support 13 does not affect the change of the crack itself. Then, the crack sensor body 9 is installed on the fixing support 13, the sensor body 9 can be fixed on the long hole 16 of the fixing support 13 through a screw, the distance between the optical lens and the target can be adjusted by changing the position of the screw, and the size of the field of view of the image sensor can be adjusted according to field application. Meanwhile, the monitored crack 10 and the target are contained in the field area 15 by adjusting the focal length of the optical lens, clear images are obtained, a power supply and a remote communication cable are connected, the sensor enters a working state, and crack measurement data are sent to a remote data terminal.
As shown in fig. 7 to 9, the switching mechanism 20 is composed of an electromagnet and a mounting substrate 25, the electromagnet is a product of south tomb company purchased from outsiders, and includes an electromagnetic coil 21, an armature 22 and a spring 26, and the armature 22 can extend and retract up and down in a through hole inside the electromagnetic coil 21 under the action of electromagnetic force and the spring. The head of the armature 22 is connected with a mounting base plate 25 in an adhesive bonding or other mode, and the armature 22 drives the mounting base plate 25 to synchronously move up and down when stretching. The narrow-band filter 23 and the substrate 24 are mounted on the mounting substrate 25, and when the electromagnet is electrified, the armature 22 overcomes the acting force of the spring 26 to contract, so that the substrate 24 is opposite to the position of the image sensor, and a second target image is obtained; when the electromagnet is powered off, the spring 26 drives the armature 22 to extend, so that the narrow-band filter 23 is opposite to the position of the image sensor to acquire a first target image; the mode has simple and reliable structure, and conveniently realizes the state switching of two modes. The switching mechanism may also adopt other ways such as an electromagnet plus a lever to realize the position switching of the narrowband filter, which are all conventional mechanism changes and are not exemplified here.
As shown in fig. 10 and 4, the measurement steps of the absolute width variation value of the crack according to the present invention are as follows:
【1】 Presetting parameters;
the method mainly comprises the steps of presetting an image sensor, a target distance and calibration parameters in a processor.
【2】 The imaging system switches to the second target imaging mode: the photoelectric target is closed and the narrow-band filter is not in place;
including turning off the target, a switching mechanism switches the broad spectrum substrate in front of the image sensor.
【3】 Reading the 1 st frame of image data and carrying out image processing;
the image processing includes conventional graying processing, binary segmentation, noise filtering, and the like.
【4】 Acquiring position coordinates of corresponding pixel points of two edges of the crack on the image sensor;
referring to fig. 4, the coordinate positions of the two edge curves on the sensor are obtained, and the two edge curves are stored and used for post-processing.
【5】 The imaging system switches to the first target imaging mode: opening the photoelectric target and placing the narrow-band filter in place;
【6】 Reading the 2 nd frame image data, and performing image processing;
the image processing includes conventional graying processing and the like.
【7】 Calculating to obtain the coordinates of the central position of the light spot of the target, and determining a crack measuring line and the position of the crack measuring line at the pixel point of the image sensor;
referring to fig. 4, AB is a crack measurement line, and the coordinate position of a pixel point corresponding to each point on the AB connection line can be obtained through calculation.
【8】 Comparing with the 1 st frame image to obtain the pixel coordinate position of the intersection point of the crack measuring line and the crack edge;
and obtaining the coordinate position of the pixel point corresponding to the CD point.
【9】 Obtaining an absolute width value of the crack according to the target distance, the target and the pixel coordinate position of the intersection point;
referring to fig. 4, let A, B, C, D be (x) respectively as the coordinates of the pixel points on the image sensora，ya)、(xb，yb)、(xc，yc)、(xd，yd) P is the distance between two targets AB known in advance, the distance q between CDs to be measured1Can be expressed as:
【10】 Repeating the steps from [ 5 ] to [ 9 ] to obtain the absolute width value q of the crack of 2 to n frames2To qnThe absolute width of the crack is the dynamic change value of the absolute width of the crack;
as a further implementation manner, the steps [ 1 ] to [ 10 ] are repeated every time length T, mutual calibration between the first target image and the second target image is performed for one time, the measured dynamic change value is corrected, and the subsequent measurement result is calculated according to the new calibration parameter, so as to improve the measurement accuracy. The interval duration T can be 24 hours, and the measurement mode and the measurement result can meet the monitoring requirement of the cracks on the existing large-scale structure.
Claims (10)
1. An absolute measuring device of dynamic change parameters of cracks is characterized in that: the sensor comprises a sensor body (9) and two photoelectric targets arranged on two sides of a crack to be detected on a structural body, wherein a connecting line between the two photoelectric targets is vertical to the trend of the crack; the sensor body comprises a machine shell (7), an optical lens (1) arranged in the machine shell (7), an image sensor (2) and a core control unit (3), wherein the optical lens (1) aims at a photoelectric target, and a narrow-band filter (23) with a position switching function is arranged between the optical lens (1) and the image sensor (2); the transmission wavelength of the narrow-band filter is matched with the emergent wavelength of the photoelectric target;
a switching structure (20) is arranged on the shell (8) and drives the narrow-band filter (23) to realize position switching; the core control unit (3) controls the switch and the switching structure (20) of the photoelectric target, so that the image sensor (2) obtains a first target image when the narrowband filter (23) is positioned in front of the image sensor (2) and the photoelectric target is turned on and a second target image when the narrowband filter (23) is not positioned in front of the image sensor (2) and the photoelectric target is turned off in a time-sharing manner, and then the dynamic change value of the absolute width of the crack in the target view field is calculated.
2. An absolute measurement device of dynamic parameters of fractures according to claim 1, characterized in that: the switching mechanism (20) is composed of an electromagnet and a mounting substrate (25), the electromagnet comprises an electromagnetic coil (21), a spring (26) and an armature (22), the electromagnetic coil (21) drives the armature (22) to stretch and retract so as to drive the mounting substrate (25) to switch positions, and the narrow-band filter (23) is fixed on the mounting substrate (25).
3. An absolute measurement device of dynamic parameters of fractures according to claim 2, characterized in that: the mounting substrate (25) is provided with a narrow-band filter (23) and a substrate (24) transmitting a broad spectrum, and when a second target image is acquired, the substrate (24) is positioned between the image sensor (2) and the optical lens (1).
4. An absolute measurement device of a dynamic variation parameter of a fracture according to any of claims 1 to 3, characterized in that: the sensor body further comprises a remote communication unit (6), and the remote communication unit (6) transmits the processing result to a remote data center under the control of the core control unit (3).
5. An absolute measurement device of a dynamic variation parameter of a fracture according to any of claims 1 to 3, characterized in that: the sensor body also comprises a power management unit (5), and the switch of the photoelectric target and the electromagnetic coil (21) are powered on and off under the control of the core control unit (3).
6. An absolute measurement device of a dynamic variation parameter of a fracture according to any of claims 1 to 3, characterized in that: a white light lamp (30) is arranged at one end of the casing (8) close to the structural body (11) to realize the illumination of the target.
7. An absolute measurement device of a dynamic variation parameter of a fracture according to any of claims 1 to 3, characterized in that: the target is an LED lamp or a light emitting diode, and the output spectrum of the LED lamp or the light emitting diode is a near-infrared band.
8. An absolute measurement device of a dynamic variation parameter of a fracture according to any of claims 1 to 3, characterized in that: the machine shell (7) is fixed on the surface of the structural body (11) on one side of the slit through the fixing support (13), and the fixing support (13) is provided with a long hole for fixing the sensor body, so that the adjustment of the distance between the optical lens (1) and the target is realized.
9. A method for absolute measurement of a dynamic change parameter of a fracture using the absolute measurement apparatus of a dynamic change parameter of a fracture according to any one of claims 1 to 8, comprising the steps of:
【1】 Presetting parameters;
【2】 The measuring device switches to the second target imaging mode: the photoelectric target is turned off and the narrowband filter is not in front of the image sensor;
【3】 Reading the 1 st frame of image data and carrying out image processing;
【4】 Acquiring position coordinates of corresponding pixel points of two edges of the crack on the image sensor;
【5】 The measuring device switches to the first target imaging mode: the photoelectric target is opened and the narrowband filter is positioned in front of the image sensor;
【6】 Reading the 2 nd frame image data, and performing image processing;
【7】 Calculating to obtain the coordinates of the central position of the light spot of the target, and determining a crack measuring line and the position of the crack measuring line at the pixel point of the image sensor;
【8】 Comparing with the 1 st frame image to obtain the pixel coordinate position of the intersection point of the crack measuring line and the crack edge;
【9】 Obtaining an absolute width value of the crack according to the target distance, the target and the pixel coordinate position of the intersection point;
【10】 And (5) repeating the steps (5) to (9) to obtain the absolute width value of the crack of 2 to n frames, namely the dynamic change value of the absolute width of the crack.
10. The absolute measurement method of dynamic parameters of fractures according to claim 9, characterized in that the steps [ 1 ] to [ 10 ] are repeated after a set period of time at intervals.
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111398014A (en) * | 2020-03-30 | 2020-07-10 | 河海大学 | Correction method for shear-type fracture test of magnetic suspension soil body |
| CN111536881A (en) * | 2020-05-09 | 2020-08-14 | 广东有色工程勘察设计院 | Crack automatic detector with camera |
| CN114353670A (en) * | 2022-01-07 | 2022-04-15 | 深圳市北斗云信息技术有限公司 | Method for measuring cracks through visual multi-parameter intelligent crack meter |
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2019
- 2019-11-28 CN CN201911188391.3A patent/CN110926343A/en active Pending
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111398014A (en) * | 2020-03-30 | 2020-07-10 | 河海大学 | Correction method for shear-type fracture test of magnetic suspension soil body |
| CN111398014B (en) * | 2020-03-30 | 2020-12-08 | 河海大学 | Correction method for shear-type fracture test of magnetic suspension soil body |
| CN111536881A (en) * | 2020-05-09 | 2020-08-14 | 广东有色工程勘察设计院 | Crack automatic detector with camera |
| CN114353670A (en) * | 2022-01-07 | 2022-04-15 | 深圳市北斗云信息技术有限公司 | Method for measuring cracks through visual multi-parameter intelligent crack meter |
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