CN114170160A - Steel bar classified scanning planning method based on geometric model - Google Patents

Steel bar classified scanning planning method based on geometric model Download PDF

Info

Publication number
CN114170160A
CN114170160A CN202111410680.0A CN202111410680A CN114170160A CN 114170160 A CN114170160 A CN 114170160A CN 202111410680 A CN202111410680 A CN 202111410680A CN 114170160 A CN114170160 A CN 114170160A
Authority
CN
China
Prior art keywords
point
steel bar
scanning
laser scanner
plane
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
CN202111410680.0A
Other languages
Chinese (zh)
Inventor
蔡长青
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Guangzhou University
Original Assignee
Guangzhou University
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Guangzhou University filed Critical Guangzhou University
Priority to CN202111410680.0A priority Critical patent/CN114170160A/en
Publication of CN114170160A publication Critical patent/CN114170160A/en
Pending legal-status Critical Current

Links

Images

Classifications

    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
    • G06T7/00—Image analysis
    • G06T7/0002—Inspection of images, e.g. flaw detection
    • G06T7/0004—Industrial image inspection
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
    • G01B11/00—Measuring arrangements characterised by the use of optical techniques
    • G01B11/24—Measuring arrangements characterised by the use of optical techniques for measuring contours or curvatures
    • G01B11/25—Measuring arrangements characterised by the use of optical techniques for measuring contours or curvatures by projecting a pattern, e.g. one or more lines, moiré fringes on the object
    • G01B11/2518—Projection by scanning of the object
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06F—ELECTRIC DIGITAL DATA PROCESSING
    • G06F18/00—Pattern recognition
    • G06F18/20—Analysing
    • G06F18/24—Classification techniques
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
    • G06T7/00—Image analysis
    • G06T7/60—Analysis of geometric attributes
    • G06T7/62—Analysis of geometric attributes of area, perimeter, diameter or volume
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
    • G06T7/00—Image analysis
    • G06T7/60—Analysis of geometric attributes
    • G06T7/66—Analysis of geometric attributes of image moments or centre of gravity
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
    • G06T7/00—Image analysis
    • G06T7/70—Determining position or orientation of objects or cameras
    • G06T7/73—Determining position or orientation of objects or cameras using feature-based methods
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
    • G06T2207/00—Indexing scheme for image analysis or image enhancement
    • G06T2207/20—Special algorithmic details
    • G06T2207/20081—Training; Learning
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
    • G06T2207/00—Indexing scheme for image analysis or image enhancement
    • G06T2207/30—Subject of image; Context of image processing
    • G06T2207/30108—Industrial image inspection
    • G06T2207/30136—Metal

Landscapes

  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Theoretical Computer Science (AREA)
  • General Physics & Mathematics (AREA)
  • Computer Vision & Pattern Recognition (AREA)
  • Data Mining & Analysis (AREA)
  • Geometry (AREA)
  • Bioinformatics & Cheminformatics (AREA)
  • Evolutionary Computation (AREA)
  • Evolutionary Biology (AREA)
  • General Engineering & Computer Science (AREA)
  • Bioinformatics & Computational Biology (AREA)
  • Artificial Intelligence (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Quality & Reliability (AREA)
  • Length Measuring Devices By Optical Means (AREA)

Abstract

The invention discloses a steel bar classified scanning planning method based on a geometric model, which is characterized by comprising the following steps of: developing a geometric relation model; tuning the analog scanning point; a target laser scanner position is determined. By using the steel bar classified scanning planning method based on the geometric model, provided by the invention, the scanning position of the laser scanner can be selected, so that the steel bar detection precision is improved, the intelligent steel bar diameter and interval estimation is realized, the labor burden of a construction site is reduced, and the construction efficiency is improved. The invention is widely applied to the field of building construction.

Description

Steel bar classified scanning planning method based on geometric model
Technical Field
The invention relates to the field of laser scanning contour extraction, in particular to a steel bar classified scanning planning method based on a geometric model.
Background
In the construction process, in order to check whether the known reinforced concrete structure meets the design bearing capacity and structural integrity, the diameter of the steel bar before the concrete construction needs to be checked. The traditional method is to use a measuring scale to manually measure the reinforcing steel bars, which not only consumes manpower, but also is easy to make mistakes. In recent years, methods based on laser scanning have been proposed, using laser scanning techniques for steel bar diameter and pitch estimation. However, these methods have limitations not only in accurately classifying the diameters of the small-sized reinforcing bars, but also in determining the target positions of the laser scanners to ensure accurate checking of the sizes of the reinforcing bars.
Disclosure of Invention
In view of the above, the invention develops a model for defining the geometric relationship between the steel bar layout and the laser scanner, and provides a steel bar classification scanning planning method based on the geometric model.
The invention provides a steel bar classified scanning planning method based on a geometric model, which comprises the following steps:
developing a geometric relation model, wherein the geometric relation model comprises a plurality of steel bars, a laser scanner and a spatial rectangular coordinate system which is established by an x axis and a z axis which are parallel to the cross section of the steel bars and are vertical to each other and a y axis which is parallel to the axis of the steel bars;
tuning the analog scanning point;
a target laser scanner position is determined.
Further, the developing a geometric relationship model, specifically, establishing a geometric relationship model according to a position relationship between the laser scanner and the steel bar, specifically includes the following steps:
the cross section of the steel bar is circular, and the circle center of the cross section of the steel bar is determined as the origin (x) of the coordinate system0，y0，z0)；
Determining the scanning coverage rate on the steel bar;
determining a laser beam line equation;
the coordinates of the scanning point are calculated.
Further, the determining the scanning coverage rate on the steel bar specifically includes:
the scanning coverage of the upper layer of steel bars is determined by the following method:
the emission point of the laser scanner is defined as t (x)t，yt，zt) The emitting point emits laser to the reinforcing steel bar to obtain two tangent scanning points (tangent points)
Figure BDA0003373650200000011
And
Figure BDA0003373650200000012
further obtaining the vector from the emitting point to the two tangent points
Figure BDA0003373650200000021
And
Figure BDA0003373650200000022
a is to1And a2The curve edge of the cross section of the steel bar between the two is defined as a scanning range, and the scanning range is obtained by the following calculation:
the vector from the tangent point to the center of the circle is
Figure BDA0003373650200000023
And
Figure BDA0003373650200000024
tangent point a1、a2The coordinates of (a) are:
Figure BDA0003373650200000025
Figure BDA0003373650200000026
Figure BDA0003373650200000027
wherein k is1Is a vector
Figure BDA0003373650200000028
Slope in the xOz plane, expressed as:
Figure BDA0003373650200000029
r is the radius of the cross section of the steel bar;
Figure BDA00033736502000000210
Figure BDA00033736502000000211
Figure BDA00033736502000000212
wherein k is1Is a vector
Figure BDA00033736502000000213
Slope in the xOz plane, expressed as:
Figure BDA00033736502000000214
scanning coverage rate of a1、a2The area in between is obtained;
the scan coverage of the underlying rebar is determined using the following method:
calculating the emission point t (x) from the laser scannert，yt，zt) To the tangent point a of the surface layer steel bar1、a2Vector of (2)
Figure BDA00033736502000000215
Retention
Figure BDA00033736502000000216
The vector passing through the tangent point of the surface layer steel bar to reach the surface of the bottom layer steel bar is recorded as a boundary point
Figure BDA00033736502000000217
The vector from the emission point to the boundary point is
Figure BDA00033736502000000218
Calculating the emission point t (x) from the laser scannert，yt，zt) To the tangent point of the underlying reinforcement
Figure BDA00033736502000000219
Tangent point
Figure BDA00033736502000000220
To the boundary point
Figure BDA00033736502000000221
The area between the two steel bars is the scanning range, and the scanning coverage rate of the bottom steel bar is further calculated.
Further, the determining the laser beam line equation comprises the following steps:
creating an auxiliary plane beta above the reinforcing steel bar;
generating target points on the auxiliary plane β:
determining a laser beam line equation;
wherein, the creating of the auxiliary plane β above the rebar specifically comprises:
creating an auxiliary plane beta parallel to the xOy plane (rebar cross section), plane beta to the origin (x)0，y0，z0) D, the expression for plane β can be written as z ═ z0+ d; the length Lp and the width Wp of the beta are respectively greater than the length l and the radius r of the steel bar;
generating a target point on the auxiliary plane β, specifically including:
the emission point of the laser scanner is defined as t (x)t，yt，zt) The target point on the plane beta is defined as pi(xpi，ypi，zpi)；
The distance from any point on the plane beta to the target point in the x direction is defined as shiThe distance in the y direction is defined as svi；
shiAnd sviThe expression of (a) is:
Figure BDA0003373650200000031
Figure BDA0003373650200000032
θhand thetavAngular resolutions in the x-and y-directions, respectively; the starting point of the target point is positioned at the corner of the plane beta;
determining a laser beam line equation specifically comprises:
the equation for the laser beam line L emitted by the laser scanner is:
Figure BDA0003373650200000033
the parameters of the laser beam line L depend on the target point piAnd (4) expressing.
Further, the calculating the coordinates of the scanning point comprises the following steps:
the emission point of the laser scanner is defined as t (x)t，yt，zt) Defining the intersection point of the laser beam line and the steel bar as a scanning point ni(xni，yni，zni)；
Calculating xni、zni；
Calculating yni；
Wherein x is calculatedni、zniThe method specifically comprises the following steps:
the steel bar is projected to the xOz plane (the cross section of the steel bar), and the coordinates of the emission point t in the xOz plane are (x)t，zt) Target point piHas the coordinates of (x)pi，zpi) Scanning point niHas the coordinates of (x)ni，zni)；
The equation for the laser beam line L in the xOz plane is:
Figure BDA0003373650200000041
eliminating the laser beam outside the scanning range;
the cross-sectional equation is: (x)0-xni)2+(z0-zni)2＝r2
Obtaining two groups of x through a laser beam line equation L and a cross section equationni、zniAs a result, take z thereinniThe group with large value is used as final xni、zniCalculating a result;
calculating yniThe method specifically comprises the following steps:
the steel bar is projected to the yOz plane (steel bar longitudinal section), and the coordinates of the emission point t in the yOz plane are (y)t，zt) Target point piHas the coordinates of
Figure BDA0003373650200000042
Scanning point niHas the coordinates of (y)ni，zni)；
The following can be obtained:
Figure BDA0003373650200000043
obtained yniAs a final calculation result.
Further, the tuning the analog scanning point includes the following steps:
eliminating a shielding area in the simulated lower-layer steel bar;
measurement noise is generated.
Further, eliminating the occlusion region in the simulated lower layer steel bar specifically includes:
acquiring a boundary point of a laser beam line and a lower-layer steel bar intersection when the laser beam line emitted by a laser scanner is tangent to the edge of the upper-layer steel bar; the area between the boundary points is the shielding area;
and eliminating the scanning points in the shielding area according to the space coordinate positioning.
Further, the generating of the measurement noise specifically includes:
and setting the distance deviation R between the measurement coordinate and the actual coordinate of the scanning point according to the Gaussian distribution, wherein the average value of R is 0, and the variance is the measurement error of the laser scanner.
Further, the determining the target laser scanner position comprises the following steps:
generating potential laser scanner locations;
simulating scanning points on the layout of the reinforcing steel bars;
a target laser scanner position is determined.
Further, the determining the position of the target laser scanner specifically includes:
for each possible laser scanner position, steel bar diameter prediction is performed using a density-based machine learning method, and the laser scanner position with the highest prediction accuracy is selected as the target laser scanner position.
The invention has the following beneficial effects: by using the steel bar classified scanning planning method based on the geometric model, provided by the invention, the selection of the target scanning position of the laser scanner can be realized, so that the steel bar detection precision is improved, the intelligent steel bar diameter and interval estimation is realized, the labor burden of a construction site is reduced, and the construction efficiency is improved.
Drawings
In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.
FIG. 1 is a general flow chart of a steel bar classification scanning planning method based on a geometric model;
FIG. 2 is a schematic of the outputs and outputs of developing a geometric relational model;
FIG. 3 is a graphical representation of a scan coverage calculation to determine the upper and lower layer reinforcement bars;
FIG. 4 is a graphical representation of laser beam line equation calculations;
FIG. 5 is a three-dimensional graphical representation of scan point coordinate calculations;
FIG. 6 is a two-dimensional graphical representation of scan point coordinate calculations;
FIG. 7 is a diagrammatic view of an occluded area during the step of eliminating the occluded area in the underlying rebar;
FIG. 8 is a graphical representation of noise in the step of generating measurement noise;
FIG. 9 is a three-dimensional grid representation of the step of generating potential laser scanner positions.
Detailed Description
In order to make the objects, technical solutions and advantages of the present application more apparent, the present application is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present application and are not intended to limit the present application.
The embodiment introduces the general flow of a steel bar classification scanning planning method based on a geometric model, and as shown in fig. 1, the embodiment is divided into three steps, firstly, simulation of scanning points is performed in the first two steps, including (1) developing a geometric relation model and (2) simulating tuning of the scanning points. In step (1), the laser scanner, the steel bar layout and the geometric relationship among the scanning points on the steel bar are modeled to calculate the coordinates of the scanning points on the steel bar layer. Then, in step (2), the scanning point is adjusted by eliminating the scanning point of the lower layer steel bar shielding area and generating measurement noise. And finally, finishing the step (3) to determine the target position of the laser scanner in a prior state based on the established geometric model.
The detailed procedure of each step will be explained below.
This embodiment describes the process of step (1) to develop a geometric relationship model based on the relationship between the laser scanner and the arrangement of the steel bars. As shown in FIG. 2, the input parameters of the model include (r) the emission point t (x) of the laser scannert，yt，zt) And (2) designing a reinforcing bar layout letterThe method comprises the steps of (1) forming a steel bar space(s) and a steel bar radius (r); the output of the model is a scanning point n on the bari(xni，yni，zni). On the premise that the design model can be used for steel bar inspection, the steel bar spacing(s) and the steel bar radius (r) can be obtained according to the design geometric information of the target steel bar layout.
The development of the geometric relationship model mainly comprises three steps: 101 determines the scan coverage on the rebar, 102 determines the laser beam line equation, and 103 calculates the coordinates of the scan point.
Determination of scan coverage on rebar 101:
establishing a space rectangular coordinate system with an x axis and a z axis which are parallel to the cross section of the steel bar and are perpendicular to each other and a y axis which is parallel to the axis of the steel bar, wherein the origin (x) of the coordinate system0，y0，z0) The center of a cross section of the steel bar;
the scanning coverage of the upper layer of steel bars is determined by the following method:
the emission point of the laser scanner is defined as t (x)t，yt，zt) The emitting point emits laser to the reinforcing steel bar to obtain two tangent scanning points (tangent points)
Figure BDA0003373650200000061
And
Figure BDA0003373650200000062
further obtaining the vector from the emitting point to the two tangent points
Figure BDA0003373650200000063
And
Figure BDA0003373650200000064
a is to1And a2The curve edge of the cross section of the steel bar between the two is defined as a scanning range, and the scanning range is obtained by the following calculation:
the vector from the tangent point to the center of the circle is
Figure BDA0003373650200000065
And
Figure BDA0003373650200000066
equation (1) (2) can be established from the mathematical relationship:
by
Figure BDA0003373650200000067
Is provided with
Figure BDA0003373650200000068
Figure BDA0003373650200000069
Figure BDA00033736502000000610
From the radius of the circle, there are
Figure BDA00033736502000000611
Further deducing the tangent point a from the formulas (1) and (2)1、a2The coordinates of (a):
Figure BDA00033736502000000612
Figure BDA00033736502000000613
Figure BDA00033736502000000614
wherein k is1Is a vector
Figure BDA0003373650200000071
Slope in the xOz plane, expressed as:
Figure BDA0003373650200000072
Figure BDA0003373650200000073
Figure BDA0003373650200000074
Figure BDA0003373650200000075
wherein k is1Is a vector
Figure BDA0003373650200000076
Slope in the xOz plane, expressed as:
Figure BDA0003373650200000077
scanning coverage rate of a1、a2The area in between is obtained;
the scan coverage of the underlying rebar is determined using the following method:
calculating the emission point t (x) from the laser scannert，yt，zt) To the tangent point a of the surface layer steel bar1、a2Vector of (2)
Figure BDA0003373650200000078
Retention
Figure BDA0003373650200000079
The vector passing through the tangent point of the surface layer steel bar to reach the surface of the bottom layer steel bar is recorded as a boundary point
Figure BDA00033736502000000710
The vector from the emission point to the boundary point is
Figure BDA00033736502000000711
Calculating the emission point t (x) from the laser scannert，yt，zt) To the tangent point of the underlying reinforcement
Figure BDA00033736502000000712
Tangent point
Figure BDA00033736502000000713
To the boundary point
Figure BDA00033736502000000714
The area between the two steel bars is the scanning range, and the scanning coverage rate of the bottom steel bar is further calculated.
The reason for separately calculating the upper-layer steel bars and the lower-layer steel bars is that one tangent point of the lower-layer steel bars cannot be acquired by the laser scanner due to shielding of the upper-layer steel bars, so that the boundary points of the lower-layer steel bars are acquired through the tangent points of the upper-layer steel bars, and the area between the boundary points and the tangent points is scanned, which is the most accurate acquisition method, and the mathematical graph is shown in fig. 3.
The laser beam line equation is determined for 102: after obtaining the scanning range and the two tangent points of the reinforcing bar, an equation of a plurality of laser beam lines emitted from the laser scanner to the reinforcing bar is calculated. As shown in fig. 4, three steps are included:
102 a: creating an auxiliary plane beta above the reinforcing steel bar;
102 b: generating target points on the auxiliary plane β:
102 c: determining a laser beam line equation;
regarding 102 a: creating an auxiliary plane β above the rebar, including in particular:
creating an auxiliary plane beta parallel to the xOy plane (rebar cross section), plane beta to the origin (x)0，y0，z0) D, the expression for plane β can be written as z ═ z0+ d; the length Lp and width Wp of beta being greater than the bar, respectivelyLength l and radius r;
regarding 102 b: generating a target point on the auxiliary plane β, specifically including:
the target point on the plane beta is defined as
Figure BDA0003373650200000081
The distance from any point on the plane beta to the target point in the x direction is defined as shiThe distance in the y direction is defined as svi；
shiAnd sviObtained by the following calculation:
Figure BDA0003373650200000082
Figure BDA0003373650200000083
θhand thetavAngular resolutions in the x-and y-directions, respectively; the starting point of the target point is positioned at the corner of the plane beta;
regarding 102 c: determining a laser beam line equation specifically comprises:
the equation for the laser beam line L emitted by the laser scanner is:
Figure BDA0003373650200000084
the laser beam line L is based on the target point piAnd (4) expressing.
Regarding 103 calculation of the coordinates of the scanning points:
the three-dimensional view and the two-dimensional view of the scanning point coordinate calculation are respectively fig. 5 and fig. 6.
Defining the intersection point of the laser beam line and the steel bar as a scanning point ni(xni，yni，zni)；
Calculating xni、zni；
Calculating yni；
Wherein x is calculatedni、zniThe method specifically comprises the following steps:
the steel bar is projected to the xOz plane (the cross section of the steel bar), and the coordinates of the emission point t in the xOz plane are (x)t，zt) Target point piHas the coordinates of
Figure BDA0003373650200000085
Scanning point niHas the coordinates of (x)ni，zni)；
Through the emission point t and the target point piDetermining an equation for the laser beam line L in the xOz plane:
Figure BDA0003373650200000086
eliminating the laser beam outside the scanning range;
obtaining a cross section equation by a circle center formula: (x)0-xni)2+(z0-zni)2＝r2
Obtaining two groups of x through a laser beam line equation L and a cross section equationni、zniAs a result, take z thereinniA larger group as the final xni、zniCalculating a result;
calculating yniThe method specifically comprises the following steps:
the steel bar is projected to the yOz plane (steel bar longitudinal section), and the coordinates of the emission point t in the yOz plane are (y)t，zt) Target point piHas the coordinates of
Figure BDA0003373650200000091
Scanning point niHas the coordinates of (y)ni，zni)；
Through the emission point t and the target point piDetermine the equation for the laser beam line L in the yOz plane:
Figure BDA0003373650200000092
will find zniSubstituting into the laser beam line equation to obtain yni
Figure BDA0003373650200000093
Obtained yniAs a final calculation result.
This embodiment describes (2) a procedure of tuning of an analog scanning point. This step is divided into two substeps: the elimination of the occlusion areas in the underlying rebar 201 and the generation of measurement noise 202.
Regarding 201 elimination of occlusion regions in underlying rebar: as shown in fig. 7, in different reinforcement layers, the connection area between the transverse reinforcement of the upper layer and the longitudinal reinforcement of the lower layer becomes a shielding area, which cannot be scanned accurately by the laser scanner, so that the scanning points in these areas need to be removed. Firstly, acquiring a tangent point, a laser beam line L 'of the upper layer transverse steel bar'iIs determined to pass through the emission point t (x)t，yt，zt) And point of tangency
Figure BDA0003373650200000094
The line of (2). Then, boundary points of the occlusion region are calculated
Figure BDA0003373650200000095
As line L'iAnd the intersection of the cross section of the rebar. And finally, eliminating scanning points falling on a shielding area in the lower-layer longitudinal steel bar. The orientation of the reinforcing bars in this embodiment is only used as an example, and those skilled in the art can select a suitable stacking manner of the reinforcing bars according to their own needs.
Measurement noise generation with respect to 202: as shown in fig. 8, since the laser scanner must have a certain degree of measurement error in actual use, calculating the coordinates of the scanning point using an accurate geometric model may not accurately obtain the actual coordinates of the scanning point. Therefore, the embodiment adds measurement noise in the geometric model to reflect the system error of the laser scanner, and the robustness of the method is improved. First assume a system of measurement instrumentsThe total measurement error is E, and each analog scanning point ni(xni，yni，zni) Are gaussian distributed, i.e. their mean value mu is 0 and the variance sigma is2E. For each scanning point ni(xni，yni，zni) It is not located at a predetermined position, but randomly located on a spherical surface centered at the predetermined position with a radius R. Thus, each analog scanning point ni(xni，yni，zni) The scanning point is updated to nei(xnei，ynei，znei)。
This embodiment describes the determination of the position of the laser scanner. Determining a target laser scanner position according to the following three steps: 301 generates potential laser scanner positions, 302 simulates scan points on the rebar layout, and 303 determines target laser scanner positions.
For 301 generation of potential laser scanner locations: a set of potential mirror positions is created over the rebar. Fig. 9 shows the generation of potential laser scanner locations above the rebar. By creating a three-dimensional grid with user-defined resolution and treating the intersection as a potential laser scanner position ti(xti，yti，zti). A dense 3D grid will result in a large number of potential laser scanner positions, resulting in a higher performance of the determined target laser scanner positions.
Simulation for scanning points on 302 rebar placement: for each possible laser scanner position, the scan points on the rebar are simulated using the developed geometric model and measurement noise. To this end, a simulation process based on a geometric model derived from mathematical equations can be implemented into software using MATLAB (ver 2015 b).
Determination of target laser scanner position with 303: for each possible laser scanner position, a steel bar diameter prediction is made using a density-based machine learning algorithm. Each potential laser scanner ti(xti，yti，zti) The prediction accuracy of (a) is denoted as Acc (i). Finally, the target laser scanner is determined to beAcc (i) the highest potential laser scanner.
After a series of experimental tests are carried out on the steel bar sample, the results show that: 1) the simulation scanning data and the actual scanning data have similarity of more than 90% in the aspects of scanning density and scanning coverage rate of the surface of the steel bar; 2) the steel bar classification precision reaches 89.3%, and the effectiveness of the established mathematical model and the scanning planning method is proved.
The embodiment of the invention also discloses a computer program product or a computer program, which comprises computer instructions, and the computer instructions are stored in a computer readable storage medium. The computer instructions may be read by a processor of a computer device from a computer-readable storage medium, and executed by the processor to cause the computer device to perform the method illustrated in fig. 1.
In alternative embodiments, the functions/acts noted in the block diagrams may occur out of the order noted in the operational illustrations. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality/acts involved. Furthermore, the embodiments presented and described in the flow charts of the present invention are provided by way of example in order to provide a more thorough understanding of the technology. The disclosed methods are not limited to the operations and logic flows presented herein. Alternative embodiments are contemplated in which the order of various operations is changed and in which sub-operations described as part of larger operations are performed independently.
Furthermore, although the present invention is described in the context of functional modules, it should be understood that, unless otherwise stated to the contrary, one or more of the described functions and/or features may be integrated in a single physical device and/or software module, or one or more functions and/or features may be implemented in a separate physical device or software module. It will also be appreciated that a detailed discussion of the actual implementation of each module is not necessary for an understanding of the present invention. Rather, the actual implementation of the various functional modules in the apparatus disclosed herein will be understood within the ordinary skill of an engineer, given the nature, function, and internal relationship of the modules. Accordingly, those skilled in the art can, using ordinary skill, practice the invention as set forth in the claims without undue experimentation. It is also to be understood that the specific concepts disclosed are merely illustrative of and not intended to limit the scope of the invention, which is defined by the appended claims and their full scope of equivalents.
The functions, if implemented in the form of software functional units and sold or used as a stand-alone product, may be stored in a computer readable storage medium. Based on such understanding, the technical solution of the present invention may be embodied in the form of a software product, which is stored in a storage medium and includes instructions for causing a computer device (which may be a personal computer, a server, or a network device) to execute all or part of the steps of the method according to the embodiments of the present invention. And the aforementioned storage medium includes: a U-disk, a removable hard disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a magnetic disk or an optical disk, and other various media capable of storing program codes.
The logic and/or steps represented in the flowcharts or otherwise described herein, e.g., an ordered listing of executable instructions that can be considered to implement logical functions, can be embodied in any computer-readable medium for use by or in connection with an instruction execution system, apparatus, or device, such as a computer-based system, processor-containing system, or other system that can fetch the instructions from the instruction execution system, apparatus, or device and execute the instructions. For the purposes of this description, a "computer-readable medium" can be any means that can contain, store, communicate, propagate, or transport the program for use by or in connection with the instruction execution system, apparatus, or device.
More specific examples (a non-exhaustive list) of the computer-readable medium would include the following: an electrical connection (electronic device) having one or more wires, a portable computer diskette (magnetic device), a Random Access Memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber device, and a portable compact disc read-only memory (CDROM). Additionally, the computer-readable medium could even be paper or another suitable medium upon which the program is printed, as the program can be electronically captured, via for instance optical scanning of the paper or other medium, then compiled, interpreted or otherwise processed in a suitable manner if necessary, and then stored in a computer memory.
It should be understood that portions of the present invention may be implemented in hardware, software, firmware, or a combination thereof. In the above embodiments, the various steps or methods may be implemented in software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, any one or combination of the following techniques, which are known in the art, may be used: a discrete logic circuit having a logic gate circuit for implementing a logic function on a data signal, an application specific integrated circuit having an appropriate combinational logic gate circuit, a Programmable Gate Array (PGA), a Field Programmable Gate Array (FPGA), or the like.
In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.
While embodiments of the invention have been shown and described, it will be understood by those of ordinary skill in the art that: various changes, modifications, substitutions and alterations can be made to the embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.
While the preferred embodiments of the present invention have been illustrated and described, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims (10)

1. A steel bar classified scanning planning method based on a geometric model is characterized by comprising the following steps:
developing a geometric relation model, wherein the geometric relation model comprises a plurality of steel bars, a laser scanner and a spatial rectangular coordinate system which is established by an x axis and a z axis which are parallel to the cross section of the steel bars and are vertical to each other and a y axis which is parallel to the axis of the steel bars;
tuning the analog scanning point;
a target laser scanner position is determined.
2. The method according to claim 1, wherein the developing of the geometric relationship model, specifically, the establishing of the geometric relationship model according to the position relationship between the laser scanner and the steel bar, specifically comprises the following steps:
the cross section of the steel bar is circular, and the circle center of the cross section of the steel bar is determined as the origin (x) of the coordinate system0，y0，z0)；
Determining the scanning coverage rate on the steel bar;
determining a laser beam line equation;
the coordinates of the scanning point are calculated.
3. The method according to claim 2, wherein the determining the scanning coverage on the steel bar specifically comprises:
the scanning coverage of the upper layer of steel bars is determined by the following method:
the emission point of the laser scanner is defined as t (x)t，yt，zt) The emitting point emits laser to the reinforcing steel bar to obtain two tangent scanning points (tangent points)
Figure FDA0003373650190000011
And
Figure FDA0003373650190000012
further obtaining the vector from the emitting point to the two tangent points
Figure FDA0003373650190000013
And
Figure FDA0003373650190000014
a is to1And a2The curve edge of the cross section of the steel bar between the two is defined as a scanning range, and the scanning range is obtained by the following calculation:
the vector from the tangent point to the center of the circle is
Figure FDA0003373650190000015
And
Figure FDA0003373650190000016
tangent point a1、a2The coordinates of (a) are:
Figure FDA0003373650190000017
Figure FDA0003373650190000018
Figure FDA0003373650190000019
wherein k is1Is a vector
Figure FDA00033736501900000110
Slope in the xOz plane, expressed as:
Figure FDA00033736501900000111
r is the radius of the cross section of the steel bar;
Figure FDA0003373650190000021
Figure FDA0003373650190000022
Figure FDA0003373650190000023
wherein k is1Is a vector
Figure FDA0003373650190000024
Slope in the xOz plane, expressed as:
Figure FDA0003373650190000025
scanning coverage rate of a1、a2The area in between is obtained;
the scan coverage of the underlying rebar is determined using the following method:
calculating the emission point t (x) from the laser scannert，yt，zt) To the tangent point a of the surface layer steel bar1、a2Vector of (2)
Figure FDA0003373650190000026
Retention
Figure FDA0003373650190000027
The vector passing through the tangent point of the surface layer steel bar to reach the surface of the bottom layer steel bar is recorded as a boundary point
Figure FDA0003373650190000028
The vector from the emission point to the boundary point is
Figure FDA0003373650190000029
Calculating the emission point t (x) from the laser scannert，yt，zt) To the tangent point of the underlying reinforcement
Figure FDA00033736501900000210
Tangent point
Figure FDA00033736501900000211
To the boundary point
Figure FDA00033736501900000212
The area between the two steel bars is the scanning range, and the scanning coverage rate of the bottom steel bar is further calculated.
4. The geometric model-based rebar classification scanning planning method of claim 3, wherein the determining of the laser beam line equation comprises the following steps:
creating an auxiliary plane beta above the reinforcing steel bar;
generating target points on the auxiliary plane β:
determining a laser beam line equation;
wherein, the creating of the auxiliary plane β above the rebar specifically comprises:
creating an auxiliary plane beta parallel to the xOy plane (rebar cross section), plane beta to the origin (x)0，y0，z0) D, the expression for plane β can be written as z ═ z0+ d; the length Lp and the width Wp of the beta are respectively greater than the length l and the radius r of the steel bar;
generating a target point on the auxiliary plane β, specifically including:
the emission point of the laser scanner is defined as t (x)t，yt，zt) The target point on the plane beta is defined as pi(xpi，ypi，zpi)；
The distance from any point on the plane beta to the target point in the x direction is defined as shiThe distance in the y direction is defined as svi；
shiAnd sviThe expression of (a) is:
Figure FDA0003373650190000031
Figure FDA0003373650190000032
θhand thetavAngular resolutions in the x-and y-directions, respectively; the starting point of the target point is positioned at the corner of the plane beta;
determining a laser beam line equation specifically comprises:
the equation for the laser beam line L emitted by the laser scanner is:
Figure FDA0003373650190000033
the parameters of the laser beam line L depend on the target point piAnd (4) expressing.
5. The geometric model-based rebar classification scanning planning method according to claim 4, wherein the calculating of the coordinates of the scanning points comprises the following steps:
the emission point of the laser scanner is defined as t (x)t，yt，zt) Defining the intersection point of the laser beam line and the steel bar as a scanning point ni(xni，yni，zni)；
Calculating xni、zni；
Calculating yni；
Wherein x is calculatedni、zniThe method specifically comprises the following steps:
the steel bar is projected to the xOz plane (the cross section of the steel bar), and the coordinates of the emission point t in the xOz plane are (x)t，zt) Target point piHas the coordinates of (x)pi，zpi) Scanning point niHas the coordinates of (x)ni，zni)；
The equation for the laser beam line L in the xOz plane is:
Figure FDA0003373650190000034
eliminating the laser beam outside the scanning range;
the cross-sectional equation is: (x)0-xni)2+(z0-zni)2＝r2
Obtaining two groups of x through a laser beam line equation L and a cross section equationni、zniAs a result, take z thereinniThe group with large value is used as final xni、zniCalculating a result;
calculating yniThe method specifically comprises the following steps:
the steel bar is projected to the yOz plane (steel bar longitudinal section), and the coordinates of the emission point t in the yOz plane are (y)t，zt) Target point piHas the coordinates of (y)pi，zpi) Scanning point niHas the coordinates of (y)ni，zni)；
The following can be obtained:
Figure FDA0003373650190000041
obtained yniAs a final calculation result.
6. The geometric model-based rebar classification scanning planning method of claim 1, wherein the tuning of the simulated scanning points comprises the following steps:
eliminating a shielding area in the simulated lower-layer steel bar;
measurement noise is generated.
7. The steel bar classified scanning planning method based on the geometric model according to claim 6, wherein the eliminating and simulating the occlusion region in the lower steel bar specifically comprises:
acquiring a boundary point of a laser beam line and a lower-layer steel bar intersection when the laser beam line emitted by a laser scanner is tangent to the edge of the upper-layer steel bar; the area between the boundary points is the shielding area;
and eliminating the scanning points in the shielding area according to the space coordinate positioning.
8. The method according to claim 6, wherein the generating of the measurement noise specifically comprises:
and setting the distance deviation R between the measurement coordinate and the actual coordinate of the scanning point according to the Gaussian distribution, wherein the average value of R is 0, and the variance is the measurement error of the laser scanner.
9. The geometric model-based rebar classification scanning planning method as claimed in claim 1, wherein the determining of the target laser scanner position comprises the following steps:
generating potential laser scanner locations;
simulating scanning points on the layout of the reinforcing steel bars;
a target laser scanner position is determined.
10. The method for planning classified scanning of steel bars based on geometric model according to claim 9, wherein the determining the target laser scanner position specifically includes:
for each possible laser scanner position, a steel bar diameter prediction is made using a density-based machine learning method,
and selecting the laser scanner position with the highest prediction precision as the target laser scanner position.
CN202111410680.0A 2021-11-25 2021-11-25 Steel bar classified scanning planning method based on geometric model Pending CN114170160A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202111410680.0A CN114170160A (en) 2021-11-25 2021-11-25 Steel bar classified scanning planning method based on geometric model

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202111410680.0A CN114170160A (en) 2021-11-25 2021-11-25 Steel bar classified scanning planning method based on geometric model

Publications (1)

Publication Number Publication Date
CN114170160A true CN114170160A (en) 2022-03-11

Family

ID=80481029

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202111410680.0A Pending CN114170160A (en) 2021-11-25 2021-11-25 Steel bar classified scanning planning method based on geometric model

Country Status (1)

Country Link
CN (1) CN114170160A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115014198A (en) * 2022-05-23 2022-09-06 西南石油大学 Steel bar installation detection method based on three-dimensional laser scanning
CN117114436A (en) * 2023-07-27 2023-11-24 中冶建筑研究总院有限公司 Existing prestressed concrete member performance evaluation method based on measured data

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20180039713A1 (en) * 2016-08-02 2018-02-08 Indoor Reality Building scan window detection
CN112017293A (en) * 2020-07-10 2020-12-01 北京工业大学 Method for measuring geometric initial defects of round steel pipe

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20180039713A1 (en) * 2016-08-02 2018-02-08 Indoor Reality Building scan window detection
CN112017293A (en) * 2020-07-10 2020-12-01 北京工业大学 Method for measuring geometric initial defects of round steel pipe

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
FANGXIN LI 等: "Geometrical model based scan planning approach for the classification of rebar diameters", AUTOMATION IN CONSTRUCTION, no. 2021, pages 1 - 14 *

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115014198A (en) * 2022-05-23 2022-09-06 西南石油大学 Steel bar installation detection method based on three-dimensional laser scanning
CN117114436A (en) * 2023-07-27 2023-11-24 中冶建筑研究总院有限公司 Existing prestressed concrete member performance evaluation method based on measured data

Similar Documents

Publication Publication Date Title
Kim et al. Automated dimensional quality assessment for formwork and rebar of reinforced concrete components using 3D point cloud data
US8175734B2 (en) Methods and system for enabling printing three-dimensional object models
Xu et al. TLS-based composite structure deformation analysis validated with laser tracker
US7477262B2 (en) Automatic calculation of minimum and maximum tolerance stack
Gao et al. An approach to combine progressively captured point clouds for BIM update
US20130176312A1 (en) Systems and methods for three dimensional printing
Tedia et al. Manufacturability analysis tool for additive manufacturing using voxel-based geometric modeling
US9189572B2 (en) Simulation device, simulation system, method of simulation and program
Qiu et al. Scan planning for existing buildings without BIM based on user-defined data quality requirements and genetic algorithm
JP2012203894A (en) Three-dimensional pattern matching method
Wang et al. BIM voxelization method supporting cell-based creation of a path-planning environment
CN114170160A (en) Steel bar classified scanning planning method based on geometric model
CN114861500A (en) Method and system for automatically generating tunnel structure finite element model based on three-dimensional point cloud
Son et al. Automated model-based 3D scan planning for prefabricated building components
Li et al. Registration‐free point cloud generation technique using rotating mirrors
Huhnt Reconstruction of edges in digital building models
Błaszczak-Bąk et al. Optimization of point clouds for 3D bas-relief modeling
JP4175536B2 (en) Boundary data inside / outside judgment method and program
Liu et al. Accurate volume calculation driven by Delaunay triangulation for coal measurement
CN110688767A (en) Method for evaluating comprehensive difference degree of rock mass fracture network model precision
Kim et al. 3D reconstruction of large-scale scaffolds with synthetic data generation and an upsampling adversarial network
JP3739209B2 (en) Automatic polygon generation system from point cloud
Borisov et al. Preliminary analysis of quality of contour lines using smoothing algorithms
CN112166298B (en) Method and device for generating test plan and method and device for testing measurement object
US10529444B1 (en) System that rapidly generates a solvent-excluded surface

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination