CN114636050A - Structured light scanning type pipeline flaw detection robot and method - Google Patents
Structured light scanning type pipeline flaw detection robot and method Download PDFInfo
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- CN114636050A CN114636050A CN202210549326.4A CN202210549326A CN114636050A CN 114636050 A CN114636050 A CN 114636050A CN 202210549326 A CN202210549326 A CN 202210549326A CN 114636050 A CN114636050 A CN 114636050A
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
- F16L55/00—Devices or appurtenances for use in, or in connection with, pipes or pipe systems
- F16L55/26—Pigs or moles, i.e. devices movable in a pipe or conduit with or without self-contained propulsion means
- F16L55/28—Constructional aspects
- F16L55/30—Constructional aspects of the propulsion means, e.g. towed by cables
- F16L55/32—Constructional aspects of the propulsion means, e.g. towed by cables being self-contained
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
- F16L55/00—Devices or appurtenances for use in, or in connection with, pipes or pipe systems
- F16L55/26—Pigs or moles, i.e. devices movable in a pipe or conduit with or without self-contained propulsion means
- F16L55/28—Constructional aspects
- F16L55/40—Constructional aspects of the body
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/84—Systems specially adapted for particular applications
- G01N21/88—Investigating the presence of flaws or contamination
- G01N21/95—Investigating the presence of flaws or contamination characterised by the material or shape of the object to be examined
- G01N21/954—Inspecting the inner surface of hollow bodies, e.g. bores
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
- F16L2101/00—Uses or applications of pigs or moles
- F16L2101/30—Inspecting, measuring or testing
Abstract
The invention relates to a structured light scanning type pipeline flaw detection robot and a method, wherein the flaw detection robot comprises a machine body, a plurality of advancing assemblies, an adjusting assembly and a shooting assembly, wherein the advancing assemblies are uniformly arranged along the circumferential direction of the machine body, one side of each advancing assembly is rotatably connected with the machine body along the direction close to or far away from the machine body, and the other side of each advancing assembly is a advancing end; the adjusting components are arranged on the machine body, each adjusting component is provided with a plurality of adjusting ends which are in one-to-one correspondence with the advancing components, and the adjusting ends are connected with the corresponding advancing components and used for driving the advancing ends to rotate relative to the machine body so as to adjust the distance from the advancing ends to the machine body; the shooting assembly is arranged on the machine body; the problem of current inspection robot in the pipeline meet the road conditions of the complicacy in the pipeline, the robot is difficult for marcing, and the work of detecting a flaw receives very big hindrance is solved.
Description
Technical Field
The invention relates to the technical field of pipeline flaw detection, in particular to a structured light scanning type pipeline flaw detection robot and a method.
Background
As an important transmission means of common gas and liquid, the pipeline has serious influence on the safe operation of the pipeline due to the defects of corrosion damage of the inner wall of the pipeline, falling off of a closed rubber ring and the like in the using process, so that the inner surface of the pipeline needs to be periodically detected, and the corrosion degree, the defect size, the deformation condition and the like of the inner wall of the pipeline are known by acquiring three-dimensional shape information of the inner surface of the pipeline. The nondestructive detection of the defects of the inner wall of the pipeline has important significance for finding the defects as early as possible and reducing accidents and economic losses, the structured light vision detection technology is a novel technology and is rapidly developed in recent years, and the structured light vision detection technology is widely applied to the defect detection of the inner surface of the pipeline as an important research direction of the structured light vision detection technology.
The buried pipeline is used as a transmission carrier of oil gas and is one of important facilities of ground engineering. The pipeline is a link for connecting upstream resources and downstream users, and the pipeline is buried underground for a long time, and is corroded, perforated and leaked to bring serious loss along with the influence of factors such as time, external soil characteristics, terrain settlement and the like. Indirect losses such as plant shutdowns due to pipe damage are much larger than direct losses and are difficult to estimate. Besides considering the serious economic loss caused by the corrosion of the pipeline, the corrosion of the pipeline can cause the leakage of harmful substances, cause pollution to the environment and even cause sudden disastrous accidents to endanger the personal safety. Regular inspection of the pipeline is therefore of critical importance.
At present, the pipeline is usually detected by using an artificial or flaw detection robot, a utility model patent with the patent application number of 202020320848.3 discloses a walking robot for detecting flaws outside the pipeline, when a sensor at the front end detects a welding point, a controller controls a pneumatic slider on a front end annular support to be away from the pipeline, a driving device at the other end drives a runner to continue rotating so as to drive the robot to continue moving forwards, after the annular support at the front end drives the runner to completely pass through the welding point, the controller drives the pneumatic slider to push the runner to be in contact with the pipeline, and the runner drives the robot to move; treat that the sensor that is located on the ring carrier of rear end detects the place ahead when having welded solder joint, the pipeline is kept away from to the pneumatic slider on the ring carrier of controller control front end, the runner that is located the front end rotates and drives the robot and remove outside the pipeline, treat that the ring carrier that is located the rear end drives the whole process welding points backs of runner, the pneumatic slider of controller drive promotes runner and pipeline contact, runner driving robot removes to this utility model's normal walking of robot on the pipeline surface that has the welding point has been realized. However, the above-described robot only detects problems such as a pipe weld, and it is difficult to detect problems such as cracks and holes in the inner wall of the pipe, and the robot cannot continue to travel when it encounters a projection on the pipe. When detecting a flaw to the pipeline, the spare part that has irregular arch, installation on the pipeline is difficult to avoid, if meet the obstacle at every turn and all install the device of detecting a flaw again, with greatly reduced efficiency.
Therefore, when the existing pipeline internal flaw detection robot meets complex road conditions in a pipeline, the robot is difficult to advance, and flaw detection work is greatly hindered.
Disclosure of Invention
In view of the above, there is a need for a structured light scanning type pipeline inspection robot and a method thereof, which are used to solve the problems that when the existing pipeline inspection robot encounters complicated road conditions in a pipeline, the robot is not easy to travel, and the inspection work is greatly hindered.
The invention provides a structured light scanning type pipeline flaw detection robot which comprises a machine body, a plurality of advancing assemblies, an adjusting assembly and a shooting assembly, wherein the advancing assemblies are uniformly arranged along the circumferential direction of the advancing direction of the machine body, one side of each advancing assembly is rotatably connected with the machine body along the direction close to or far away from the machine body, and the other side of each advancing assembly is a advancing end; the adjusting components are arranged on the machine body, each adjusting component is provided with a plurality of adjusting ends which are in one-to-one correspondence with the advancing components, and the adjusting ends are connected with the corresponding advancing components and used for driving the advancing ends to rotate relative to the machine body so as to adjust the distance from the advancing ends to the machine body; the shooting assembly is installed on the body.
In some embodiments, the machine body includes two fixing plates and a plurality of sliding rods, the two fixing plates are disposed in parallel, the two fixing plates are connected via the plurality of sliding rods, and the plurality of sliding rods are disposed along a traveling direction of the machine body.
In some embodiments, each of the plurality of traveling assemblies includes a support rod and a traveling wheel, one end of the support rod is rotatably connected to the body, the other end of the support rod is provided with the traveling wheel, the traveling wheel is the traveling end, and the adjusting end is connected to the support rod to drive the support rod to rotate.
In some embodiments, the plurality of traveling assemblies each include two support rods, two traveling wheels and a connecting rod, the two support rods are sequentially arranged along the traveling direction of the machine body, one ends of the two support rods are rotatably connected with the machine body, the other ends of the support rods are respectively provided with the two traveling wheels, two ends of the connecting rod are respectively hinged to the two support rods, and the adjusting end is connected with the connecting rod to drive the support rods to rotate.
In some embodiments, the adjusting assembly includes an adjusting plate, a plurality of driving arms corresponding to the plurality of connecting rods one to one, and a telescopic member, the adjusting plate is slidably connected to the machine body along a traveling direction of the machine body, one end of each of the plurality of driving arms is hinged to the machine body, the other end of each of the plurality of driving arms is hinged to the corresponding connecting rod, the telescopic member is fixedly disposed on the machine body, and an output end of the telescopic member is connected to the adjusting plate to drive the adjusting plate to slide.
In some embodiments, the shooting assembly includes a camera and a rotator, a shooting direction of the camera is perpendicular to a traveling direction of the body, the camera is rotatably connected with the body via the rotator, and the camera is rotatably disposed with the traveling direction of the body as a rotation axis.
In some embodiments, the camera includes a camera, a bare engine, and a mounting seat, the shooting directions of the camera and the bare engine are both set along a traveling direction perpendicular to the body, the camera and the bare engine are both mounted on the mounting seat, and the mounting seat is connected to the rotator.
In some embodiments, the rotator includes a rotating shaft and a driving member, the rotating shaft is rotatably connected to the body, one end of the rotating shaft is connected to the camera, the driving member is fixedly disposed on the body, and an output end of the driving member is connected to the rotating shaft to drive the rotating shaft to rotate.
In some embodiments, the driving member includes two first bevel gears, two second bevel gears in one-to-one correspondence with the two first bevel gears, a motor, a driving spur gear, two driven spur gears, and two fixing shafts, the motor is fixedly connected to the machine body, the two fixing shafts are both rotatably connected to the machine body, one of the fixing shafts is connected to one of the first bevel gears and one of the driven spur gears, the other fixing shaft is connected to the other of the first bevel gears and the other of the driven spur gears, an output end of the motor is connected to the driving spur gear, the driving spur gears are in meshing connection with the two driven spur gears to drive the two first bevel gears to rotate, tooth surfaces of the two first bevel gears both include a semi-annular tapered tooth surface and a semi-annular sliding surface, and the two second bevel gears are in meshing connection or semi-annular tapered tooth surfaces of the corresponding first bevel gears And when one second bevel gear is in meshing connection with the semi-annular tapered tooth surface of the first bevel gear, the other second bevel gear is in sliding connection with the semi-annular sliding surface of the first bevel gear.
The invention also provides a structured light scanning type pipeline flaw detection method, which comprises the structured light scanning type pipeline flaw detection robot, and further comprises the following steps:
acquiring a curved surface image in the pipeline based on the structured light, and acquiring point cloud data and an established three-dimensional model based on the curved surface image in the pipeline;
judging whether a crack exists in the pipeline or not based on the established three-dimensional model;
and calculating to obtain the distribution density of the cracks based on the point cloud data, and judging the types of the cracks based on the distribution density of the cracks.
Compared with the prior art, in the structured light scanning type pipeline flaw detection robot provided by the invention, a plurality of advancing components can be rotatably connected with the machine body along the direction close to or far from the machine body, the plurality of adjusting ends are respectively connected with the corresponding advancing components and used for driving the advancing ends to rotate relative to the machine body so as to adjust the distance from the advancing ends to the machine body, each advancing end can be abutted against the inner wall of the pipeline through the plurality of arranged advancing ends, the advancing process of the whole robot in the pipeline is more stable, meanwhile, the robot can adapt to the requirements of pipelines with different diameters by adjusting the distance from the plurality of advancing ends to the machine body, when the complex road conditions in the pipeline are met, such as bulges or mounted parts in the pipeline, the distance from the advancing ends to the machine body can be adjusted, namely the distance from the advancing ends to the inner wall is adjusted, so as to avoid obstacles in the pipeline, the advancing work in the pipeline is smooth, and the flaw detection work of the shooting assembly is convenient to carry out.
According to the structured light scanning type pipeline flaw detection method provided by the invention, point cloud data can be obtained and a three-dimensional model can be established through the curved surface image in the pipeline acquired by structured light, so that crack points and crack types in the pipeline can be conveniently analyzed.
Drawings
Fig. 1 is a schematic structural diagram of an entire embodiment of a structured light scanning type pipeline inspection robot according to the present invention;
FIG. 2 is a schematic view of a traveling assembly and an adjusting assembly cooperatively connected in a first embodiment of a structured light scanning type pipeline inspection robot provided by the present invention;
FIG. 3 is a schematic view of a traveling assembly and an adjusting assembly cooperatively connected in a second embodiment of a structured light scanning type pipeline inspection robot provided by the present invention;
FIG. 4 is a schematic structural diagram of a camera in an embodiment of a structured light scanning type pipeline inspection robot according to the present invention;
FIG. 5 is a schematic structural diagram of a rotator in an embodiment of a structured light scanning type pipeline inspection robot according to the present invention;
FIG. 6 is a schematic diagram of a structured light scanning type pipeline inspection method according to the present invention.
Detailed Description
The accompanying drawings, which are incorporated in and constitute a part of this application, illustrate preferred embodiments of the invention and together with the description, serve to explain the principles of the invention and not to limit the scope of the invention.
As shown in fig. 1, the structured light scanning type pipeline inspection robot in the present embodiment includes a machine body 100, a plurality of traveling assemblies 200, an adjusting assembly 300, and a shooting assembly 400, wherein the plurality of traveling assemblies 200 are uniformly arranged circumferentially along a traveling direction of the machine body 100, one side of each traveling assembly 200 is rotatably connected to the machine body 100 along a direction close to or far from the machine body 100, and the other side of each traveling assembly 200 is a traveling end; the adjusting assemblies 300 are mounted on the machine body 100, each adjusting assembly 300 has a plurality of adjusting ends in one-to-one correspondence with the plurality of advancing assemblies 200, and the plurality of adjusting ends are connected with the corresponding advancing assemblies 200 for driving the advancing ends to rotate relative to the machine body 100 so as to adjust the distance from the advancing ends to the machine body 100; the photographing assembly 400 is mounted on the body 100.
Wherein, a plurality of traveling assemblies 200 can be rotatably connected with the machine body 100 along the direction approaching to or departing from the machine body 100, the plurality of adjusting ends are connected with the corresponding advancing assemblies 200, so as to drive the advancing ends to rotate relative to the machine body 100 to adjust the distance from the advancing ends to the machine body 100, and through the plurality of advancing ends, each advancing end can be abutted against the inner wall of the pipeline, so that the whole robot can more stably advance in the pipeline, meanwhile, the robot can meet the requirements of pipelines with different diameters by adjusting the distance from a plurality of traveling ends to the machine body 100, when a complex road condition in the pipeline is met, such as a protrusion or a mounted part in the pipeline, the distance from the traveling end to the machine body 100 can be adjusted, the distance from the advancing end to the inner wall is adjusted to avoid obstacles in the pipeline, the advancing work in the pipeline is smooth, and the flaw detection work of the shooting assembly 400 is facilitated.
The body 100 of the present embodiment is a structure for supporting the photographing assembly 400, on which the traveling assembly 200 is mounted, and is movable within the duct.
In some embodiments, the machine body 100 includes two fixed plates 110 and a plurality of sliding rods 120, the two fixed plates 110 are disposed in parallel, the two fixed plates 110 are connected via the plurality of sliding rods 120, and the plurality of sliding rods 120 are disposed along a traveling direction of the machine body 100.
Of course, in other preferred embodiments, the machine body 100 may also adopt other forms of structures instead, and this is not limited by the embodiment of the present invention.
The advancing assembly 200 in this embodiment is a structure for driving the machine body 100 to move, and it should be noted that the distance from the advancing assembly 200 to the machine body 100 in the embodiment of the present invention is adjustable, so as to be adaptable to pipes with different diameters and pipes with complex road conditions, which will be explained and explained in more detail below.
In some embodiments, each of the plurality of traveling assemblies 200 includes a supporting rod 210 and a traveling wheel 220, one end of the supporting rod 210 is rotatably connected to the body 100, the other end of the supporting rod 210 is provided with the traveling wheel 220, the traveling wheel 220 is a traveling end, and the adjusting end is connected to the supporting rod 210 to drive the supporting rod 210 to rotate.
Because the stability of the single-wheel traveling machine body 100 is not good unless the size of the traveling wheel 220 is designed to be larger, in order to make the traveling process of the machine body 100 more stable on the premise of the small-size traveling wheel 220, in some embodiments, the plurality of traveling assemblies 200 each include two support rods 210, two traveling wheels 220, and a connecting rod 230, which are arranged in parallel, the two support rods 210 are sequentially arranged along the traveling direction of the machine body 100, one ends of the two support rods 210 are rotatably connected with the machine body 100, the other ends of the support rods 210 are respectively provided with the two traveling wheels 220, both ends of the connecting rod 230 are respectively hinged with the two support rods 210, and the adjusting ends are connected with the connecting rod 230 to drive the support rods 210 to rotate. The double-wheel type advancing structure can enable the contact points between the machine body 100 and the pipeline to be more, and the advancing process is more stable.
It is understood that the traveling wheel 220 of the embodiment of the present invention has a power source, and can rotate spontaneously to cause the machine body 100 to travel in the pipeline.
The adjusting assembly 300 in this embodiment is a structure for adjusting the distance of the travel end to the machine body 100.
In some embodiments, the adjusting assembly 300 includes an adjusting plate 310, a plurality of driving arms 320 corresponding to the plurality of connecting rods 230 one to one, and a telescopic member 330, the adjusting plate 310 is slidably connected to the machine body 100 along the moving direction of the machine body 100, one end of each of the plurality of driving arms 320 is hinged to the machine body 100, the other end of each of the plurality of driving arms 320 is hinged to the corresponding connecting rod 230, the telescopic member 330 is fixedly disposed on the machine body 100, and an output end of the telescopic member 330 is connected to the adjusting plate 310 for driving the adjusting plate 310 to slide.
In order to facilitate understanding of the above-described adjustment process, a number of embodiments are described below. In the first embodiment, as shown in fig. 2, the adjusting plate 310 is located at the middle of the two fixing plates 110, and at this time, the driving arm 320 has a small inclination, and the traveling wheel 220 has a long distance, which is suitable for a pipe with a large pipe diameter. In the second embodiment, as shown in fig. 3, the adjusting plate 310 is closer to one of the fixing plates 110, and at this time, the driving arm 320 has a larger inclination, and the traveling wheel 220 is closer to the machine body 100, which is suitable for the case of a pipe with a smaller pipe diameter and an obstacle in the pipe.
The telescopic member 330 may be configured to drive the adjusting plate 310 to slide by using an air cylinder, an electric push rod, or the like.
Meanwhile, the adjusting assembly 300 can drive the plurality of traveling wheels 220 to move synchronously, so that the adjusting speed is higher. Of course, the adjusting assembly 300 may also be replaced by other structures, which is not limited by the embodiment of the present invention.
The photographing assembly 400 in this embodiment is used to photograph the internal structure of the pipe and photograph the inside of the pipe into desired image information.
In order to be able to perform the capturing of the entire image of the inside of the pipeline, in some embodiments, the photographing assembly 400 includes a camera 410 and a rotator 420, a photographing direction of the camera 410 is disposed in a direction perpendicular to a traveling direction of the body 100, the camera 410 is rotatably connected with the body 100 via the rotator 420, and the camera 410 is rotatably disposed with the traveling direction of the body 100 as a rotation axis. The rotator 420 drives the camera 410 to rotate, so that a complete image of the interior of the pipeline can be acquired.
It should be noted that, in the process of capturing images, the moving speed of the body 100 and the rotating speed of the rotator 420 should be well controlled to avoid the phenomenon of missed shooting.
In some embodiments, the camera 410 includes a camera 411, an optical engine 412 and a mounting seat 413, the shooting directions of the camera 411 and the optical engine 412 are both set along a direction perpendicular to the traveling direction of the machine body 100, the camera 411 and the optical engine 412 are both mounted on the mounting seat 413, and the mounting seat 413 is connected with the rotator 420. In practice, millions of projected light (structured light) projected by the optical machine 412 (i.e., grating) are projected onto the inner wall of the pipeline, and then the image is captured by the camera 411, and a three-dimensional image can be formed after the image is processed by a computer, so that the problems existing in the pipeline can be identified more accurately.
In some embodiments, the rotator 420 includes a rotating shaft 421 and a driving member 422, the rotating shaft 421 is rotatably connected to the body 100, one end of the rotating shaft 421 is connected to the camera 410, the driving member 422 is fixedly disposed on the body 100, and an output end of the driving member 422 is connected to the rotating shaft 421 to drive the rotating shaft 421 to rotate. In practice, the driving member 422 drives the rotating shaft 421 to rotate, so that the camera 410 rotates accordingly.
One end of the rotating shaft 421 is fixedly connected to the mounting seat 413 through a connecting seat 421a, and both ends of the rotating shaft 421 are rotatably connected to the two fixing plates 110 through two bearings 421 b.
In order to avoid the connecting line of the camera 410 from being wound on the rotating shaft 421 during the rotation of the rotating shaft 421, the rotating shaft 421 in the embodiment of the present invention rotates in a forward direction for one turn and then rotates in a reverse direction for one turn, and the above steps are repeated.
In a preferred embodiment, the driving member 422 includes two first bevel gears 422a, two second bevel gears 422b corresponding to the two first bevel gears 422a one by one, a motor 422c, driving spur gears 422d, two driven spur gears 422e, and two fixed shafts 422f, the motor 422c is fixedly connected to the machine body 100, the two fixed shafts 422f are rotatably connected to the machine body 100, wherein the motor 422c and the two fixed shafts 422f are both connected to the machine body 100 via a fixed base 430, one fixed shaft 422f is connected to one of the first bevel gears 422a and one of the driven spur gears 422e, the other fixed shaft 422f is connected to the other first bevel gear 422a and the other driven spur gear 422e, an output end of the motor 422c is connected to the driving spur gear 422d, the driving spur gear 422d is engaged with the two driven spur gears 422e to drive the two first bevel gears 422a to rotate, the tooth surfaces of the two first bevel gears 422a each include a semi-annular tapered tooth surface and a semi-annular sliding surface, the two second bevel gears 422b are each in meshing connection with the semi-annular tapered tooth surface of the corresponding first bevel gear 422a or in sliding connection with the semi-annular sliding surface, and when one of the second bevel gears 422b is in meshing connection with the semi-annular tapered tooth surface of the first bevel gear 422a, the other second bevel gear 422b is in sliding connection with the semi-annular sliding surface of the first bevel gear 422 a.
In implementation, first, when one of the second bevel gears 422b is engaged with the semi-annular tapered tooth surface of the first bevel gear 422a, the first bevel gear 422a rotates, the other second bevel gear 422b is slidably connected with the semi-annular sliding surface of the first bevel gear 422a, the first bevel gear 422a does not rotate, at this time, the rotating shaft 421 rotates in a forward rotation, wherein one of the second bevel gears 422b is slidably connected with the semi-annular sliding surface of the first bevel gear 422a, the first bevel gear 422a does not rotate, when the other second bevel gear 422b is engaged with the semi-annular tapered tooth surface of the first bevel gear 422a, the first bevel gear 422a rotates, at this time, the rotating shaft 421 rotates in a forward rotation, thereby realizing the reciprocating rotation process of the rotating shaft 421.
Compared with the prior art: a plurality of traveling assemblies 200 may be rotatably coupled to the body 100 in directions approaching or departing from the body 100, the plurality of adjusting ends are connected with the corresponding advancing assemblies 200, so as to drive the advancing ends to rotate relative to the machine body 100 to adjust the distance from the advancing ends to the machine body 100, and through the plurality of advancing ends, each advancing end can be abutted against the inner wall of the pipeline, so that the whole robot can more stably advance in the pipeline, meanwhile, the robot can meet the requirements of pipelines with different diameters by adjusting the distance from a plurality of traveling ends to the machine body 100, when a complex road condition in the pipeline is met, such as a protrusion or a mounted part in the pipeline, the distance from the traveling end to the machine body 100 can be adjusted, the distance from the advancing end to the inner wall is adjusted to avoid obstacles in the pipeline, the advancing work in the pipeline is smooth, and the flaw detection work of the shooting assembly 400 is facilitated.
The present invention also provides a structured light scanning type pipe inspection method, as shown in fig. 6, including the structured light scanning type pipe inspection robot as described above, further including the steps of:
s100, acquiring a curved surface image in the pipeline based on the structured light, and obtaining point cloud data and an established three-dimensional model based on the curved surface image in the pipeline;
s200, judging whether a crack exists in the pipeline or not based on the established three-dimensional model;
s300, calculating to obtain the crack distribution density based on the point cloud data, and judging the crack type based on the crack distribution density.
Because the interior of the pipeline is of a curved surface structure, and the image shot by the camera is a curved surface image, the embodiment of the invention obtains the curved surface image by the structured light. Specifically, structured light three-dimensional imaging is a non-contact active three-dimensional measurement technology, firstly, a structured light coding pattern is projected to the inner surface of a pipeline through a projector, the pattern can be deformed due to the fact that the heights of the surfaces of objects are inconsistent, and a camera shoots a deformed structured light image (namely a curved surface image). After the curved surface image in the pipeline is obtained, the image can be decoded by a computer, so that the one-to-one corresponding relation between the structured light image point and the projection pattern point is obtained, and the three-dimensional point cloud data of the object surface can be calculated by the triangulation principle, so that the three-dimensional reconstruction of the inner surface of the pipeline is realized, and the damage condition in the pipeline can be observed conveniently.
In order to realize the acquisition process of the curved surface image in the pipeline in the step S100, the acquisition process can be realized by an external trigger camera, a DLP4500 projector and a computer. Firstly, structured light pattern coding is carried out at a computer end, then 42 Gray code patterns are projected to the surface of an object to be detected by a projection device, a camera and a projector are synchronously triggered, the modulated fringe patterns are obtained by the camera and transmitted to the computer for fringe processing, the distribution of phases is calculated, finally, the height of the surface of the object to be detected is solved by the mapping relation between the phases and the heights, and the point cloud data can be visualized by corresponding software through three-dimensional reconstruction.
The camera adopts a Zhangyingyou camera calibration method, the checkerboard is used as a calibration board, and an internal reference matrix, an external reference matrix, a mirror distortion coefficient and the like of the camera are calibrated. The projector is used as an inverse camera to carry out calibration, so that calibration is carried out by utilizing the theory of Zhangyingyou camera calibration, and finally, internal parameters and external parameters of the projector are obtained. After the camera and the projector are calibrated, the stereoscopic vision calibration function calibration system of opencv can be directly called. The significance of image encoding and decoding is to determine the scanning angle of the coded structured light, i.e. the surface structured light system. Gray codes are different from binary codes by: code values of two adjacent pixel points of the Gray code. And respectively adopting 42 Gray code pictures of 20 pieces in the transverse direction, 20 pieces in the longitudinal direction and all black and white. The projector projects the projection grating picture to the surface of the measured object according to a certain rule, and then the camera can acquire the image and preprocess the image.
After the work is finished, the phase principal value of the grating image can be calculated by adopting a standard four-step phase shift method, and a phase principal value image is calculated by utilizing four grating images with the same frequency. And calculates its absolute phase value. The absolute phase value is calculated by utilizing the three-frequency heterodyne principle. And calculating 1 horizontal absolute phase value image according to the calculated 3 horizontal phase main value images, and calculating 1 vertical absolute phase value image according to the calculated 3 vertical phase main value images. Through the relation of phase position and height mapping, a line of the optical center of the camera and the image point can be determined, and a line of the optical center of the optical machine and the image point can be determined, so that three-dimensional coordinates are obtained, and the three-dimensional reconstruction process is realized.
In step S100, after the point cloud data is obtained, a process of splicing the point cloud data needs to be implemented, and the method is as follows:
the upper computer carries out three-dimensional reconstruction on the structured light shot image transmitted by the lower computer, and the limited visual angle of the projector is about
Therefore, 12 local three-dimensional reconstruction point cloud images are needed to be spliced by an Iterative Closest Point (ICP) algorithm
And (3) an annular three-dimensional diagram of the inner wall of the pipeline.
Let P and Q be the measured point cloud data from two different views, and the rotation matrix R and translation vector T between the target point cloud and the actually obtained measured object point cloud data
Is shown in which
The conditions are satisfied:
. The basic steps of the ICP algorithm are as follows:
step 1:
setting the initial coordinate transformation relationship as
And
；
step 2: for point cloud data under the view angle R
Calculating to obtain the nearest distance point at the view angle Q
According to the effective point judgment criterion, judging
And is and
and whether the corresponding points are effective corresponding points or not is further extracted, wherein the corresponding point set is positioned at the overlapping part of the visual angle P and the visual angle Q:
and step 3: according to the obtained two point sets
，
Solving the coordinate conversion relation by using a quaternion method
And
；
and 4, step 4: calculating an objective function:
and 5: if it is used
，
For a given convergence accuracy, then
Turning toGo to step 2. If it is not
Record of
And
and (5) carrying out point cloud splicing and finishing the program.
After the point cloud data is spliced, filtering and smoothing operations are required to improve the accuracy of the point cloud data.
First, isolated points need to be eliminated:
step 1: performing statistical analysis on the neighborhood of each point, and assuming that the distances of all points in the point cloud form Gaussian distribution, and the shape of the Gaussian distribution is the mean value
And standard deviation of
Determining, setting the first in the point cloud
The coordinates of points are
From that point to any point
The distance of (a) is:
step 2: calculating the average value and standard deviation of the distance from each point to any point as follows:
and step 3: when a point in the point cloud data is at it
The average distance of the neighborhood is
It is retained when in range and not removed for outliers in that range. Wherein
Is a multiple of the standard deviation.
Wherein, Gaussian-median filtering denoising is carried out:
gaussian filtering has a good effect on image noise reduction, and the principle is that after weighted average, the pixel value of each point of an image and the pixel values of other points in the neighborhood are obtained, so that the Gaussian filtering has a good filtering effect on noise which is subjected to normal distribution, and the overall details of the image can be kept; the median filtering method does not adopt a weighted summation mode to calculate a filtering result any more, divides an image into a plurality of square areas, replaces the pixel value of the area with the median of the pixels in the square, plays a good role in protecting the edge of a crack image, but blurs the whole image.
And (4) integrating Gaussian filtering and median filtering, and realizing the filtering of the crack image noise based on respective advantages. Through the crack image, it can be found that the gray value of a pixel point in the image is very close to the gray value of an adjacent pixel point, the gray value of a crack area is lower than the background gray value, and if the gray value of one pixel point is smaller than or far larger than the gray value of the adjacent pixel point, the pixel point is likely to be noise.
The method for judging whether the pipeline is cracked or not in the step S200 comprises the following steps:
by providing a curved surface with a slit, the curved surface will tilt in one direction along the slit when the curved surface passes the slit in that direction. Similarly, when a point cloud containing cracks passes through a crack area along one direction, the point is also inclined in the direction, and the inclination degree can also be used as a mode for describing the crack point, namely, the inclination degree of the point along a certain direction is described by using a gradient.
The point cloud extends linearly at the edge of the crack, and the points vary in gradient along the cross-sectional direction of the crack as the crack slopes. Crack edge detection can be performed on the point cloud using a method similar to Canny edge detection. Firstly, the height difference of each point along the X-axis direction and the Y-axis direction is calculated, and then the gradient value of the point is calculated.
In the above-mentioned formula,
to represent
Of dots
The coordinate values are, for example,
indicating points
Edge of
The partial derivatives in the direction of the light beams,
indicating points
Edge of
The partial derivatives in the direction of the light beams,
indicating points
Of the gradient of (c). The crack edge cannot be completely determined only by obtaining the global gradient, and the non-maximum inhibition method in the Canny edge detection technology is adopted to carry out the non-maximum inhibition on the gradient amplitude of the point cloud. And after the point cloud is subjected to non-maximum value inhibition, filtering by using a double threshold value to obtain crack edge points and edge contour points around the crack edge points.
The specific method for determining the type of the crack in step S300 is as follows: in the case of the crack S,
in order to determine the distribution density of the cracks,
the ratio of the area of the crack region to the minimum circumscribed matrix area of the crack is shown. Setting an appropriate threshold value
And
，
is an angle of inclination.
Step 1: if it is
The cracks are distributed with high density and have obvious crack fragments, and S is a complex crack; otherwise, entering step 2;
step 2:if it is
S is a complex crack; otherwise, S is a simple crack.
And step 3: get
If at all
S is a transverse crack; if it is
And S is a longitudinal crack.
Compared with the prior art, the point cloud data can be obtained and the three-dimensional model can be established through the curved surface image in the pipeline acquired by the structured light, so that the crack points and the crack types in the pipeline can be conveniently analyzed.
The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are included in the scope of the present invention.
Claims (10)
1. The structured light scanning type pipeline flaw detection robot is characterized by comprising a machine body, a plurality of advancing assemblies, an adjusting assembly and a shooting assembly;
the plurality of advancing assemblies are uniformly arranged along the circumferential direction of the advancing direction of the machine body, one side of each advancing assembly is rotatably connected with the machine body along the direction close to or far away from the machine body, and the other side of each advancing assembly is an advancing end;
the adjusting components are arranged on the machine body, each adjusting component is provided with a plurality of adjusting ends which are in one-to-one correspondence with the advancing components, and the adjusting ends are connected with the corresponding advancing components and used for driving the advancing ends to rotate relative to the machine body so as to adjust the distance from the advancing ends to the machine body;
the shooting assembly is installed on the machine body.
2. The structured light scanning type pipe inspection robot according to claim 1, wherein the body includes two fixing plates arranged in parallel therebetween and connected thereto via a plurality of slide bars each arranged along a traveling direction of the body, and a plurality of slide bars.
3. The structured light scanning type pipe inspection robot according to claim 1, wherein each of the plurality of traveling assemblies includes a support rod and a traveling wheel, one end of the support rod is rotatably connected to the body, the other end of the support rod is provided with the traveling wheel, the traveling wheel is the traveling end, and the adjustment end is connected to the support rod to drive the support rod to rotate.
4. The structured light scanning type pipeline inspection robot according to claim 1, wherein the plurality of traveling assemblies each include two support rods, two traveling wheels, and a connecting rod, the two support rods are arranged in sequence along a traveling direction of the machine body, one ends of the two support rods are rotatably connected to the machine body, the other ends of the support rods are respectively provided with two traveling wheels, both ends of the connecting rod are respectively hinged to the two support rods, and the adjusting end is connected to the connecting rod to drive the support rods to rotate.
5. The structural optical scanning type pipeline inspection robot as claimed in claim 4, wherein the adjusting assembly includes an adjusting plate, a plurality of driving arms corresponding to the plurality of connecting rods one to one, the adjusting plate is slidably connected to the machine body along a traveling direction of the machine body, one ends of the plurality of driving arms are hinged to the machine body, the other ends of the plurality of driving arms are hinged to the corresponding connecting rods, the telescopic member is fixedly disposed on the machine body, and an output end of the telescopic member is connected to the adjusting plate to drive the adjusting plate to slide.
6. The structured light scanning type pipe inspection robot according to claim 1, wherein the photographing assembly includes a camera whose photographing direction is set in a direction perpendicular to a traveling direction of the body, and a rotator via which the camera is rotatably connected to the body, the camera being rotatably set with the traveling direction of the body as a rotation axis.
7. The structured light scanning type pipe inspection robot according to claim 6, wherein the camera includes a camera, an optical engine, and a mounting base, a shooting direction of the camera and a shooting direction of the optical engine are both arranged in a direction perpendicular to a traveling direction of the machine body, the camera and the optical engine are both mounted on the mounting base, and the mounting base is connected to the rotator.
8. The robot for inspecting pipes according to claim 6, wherein the rotator comprises a rotating shaft and a driving member, the rotating shaft is rotatably connected to the body, one end of the rotating shaft is connected to the camera, the driving member is fixedly disposed on the body, and an output end of the driving member is connected to the rotating shaft for driving the rotating shaft to rotate.
9. The structured light scanning type pipeline inspection robot according to claim 8, wherein the driving member includes two first bevel gears, two second bevel gears corresponding to the two first bevel gears one by one, a motor, a driving spur gear, two driven spur gears, and two fixing shafts, the motor is fixedly connected to the machine body, the two fixing shafts are rotatably connected to the machine body, one of the fixing shafts is connected to one of the first bevel gears and one of the driven spur gears, the other fixing shaft is connected to the other of the first bevel gears and the other of the driven spur gears, an output end of the motor is connected to the driving spur gear, the driving spur gear is engaged with the two driven spur gears to drive the two first bevel gears to rotate, tooth surfaces of the two first bevel gears include a semi-annular tapered tooth surface and a semi-annular sliding surface, and when one of the second bevel gears is in meshing connection with the semi-annular tapered tooth surface of the first bevel gear, the other second bevel gear is in sliding connection with the semi-annular sliding surface of the first bevel gear.
10. A structured light scanning type pipe inspection method comprising the structured light scanning type pipe inspection robot according to any one of claims 1 to 9, further comprising the steps of:
acquiring a curved surface image in the pipeline based on the structured light, and acquiring point cloud data and an established three-dimensional model based on the curved surface image in the pipeline;
judging whether a crack exists in the pipeline or not based on the established three-dimensional model;
and calculating to obtain the distribution density of the cracks based on the point cloud data, and judging the types of the cracks based on the distribution density of the cracks.
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