CN209877895U - Cylinder diameter measurement system based on line structured light - Google Patents
Cylinder diameter measurement system based on line structured light Download PDFInfo
- Publication number
- CN209877895U CN209877895U CN201920274676.8U CN201920274676U CN209877895U CN 209877895 U CN209877895 U CN 209877895U CN 201920274676 U CN201920274676 U CN 201920274676U CN 209877895 U CN209877895 U CN 209877895U
- Authority
- CN
- China
- Prior art keywords
- structured light
- line
- acquisition device
- image acquisition
- measurement system
- 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.)
- Active
Links
Landscapes
- Length Measuring Devices By Optical Means (AREA)
Abstract
The utility model provides a cylinder diameter measuring system based on line structured light, which comprises a mounting base plate, a line laser, an image acquisition device and two brackets symmetrically arranged at the top of the mounting base plate, wherein the line laser and the image acquisition device are respectively arranged at the top ends of the two brackets, the top of the mounting base plate is provided with a slide rail on which a sliding trolley for placing a cylinder workpiece to be measured is arranged in a sliding way, the utility model adopts a line structured light method to measure the diameter size of the cylinder workpiece, the line structured light method adopts a laser triangle method as a basic measuring principle, a laser surface emitted by the line laser is projected on the surface of the cylinder workpiece to be measured and intersects with the cross section of the cylinder workpiece to be measured to form a light strip, the laser is used as a carrier for transmitting information, a high-resolution camera is used for collecting images, and a mathematical model is, the position of the light bar pixel points in the world coordinate system can be calculated through system calibration, and the diameter of the measured cylinder can be obtained.
Description
Technical Field
The utility model relates to a cylinder diameter measurement system, concretely relates to cylinder diameter measurement system based on line structure light.
Background
In the field of industrial production, it is necessary to measure the diameter of a cylindrical workpiece to determine whether the workpiece meets the requirements of the production process. At present, the diameter of a cylinder is basically measured by using a vernier caliper, the diameter of the cylinder needs to be measured for multiple times on different sections of the cylinder, and when a detector uses the vernier caliper for measurement, the detector is easily interfered by human factors, such as proficiency of the detector, a measurement operation method and the like, so that the precision of a measurement result is low, the deviation is large, the vernier caliper needs to be adjusted in each measurement, and the working efficiency is low.
SUMMERY OF THE UTILITY MODEL
The utility model aims at providing a cylinder diameter measurement system based on line structure light can improve work efficiency greatly, guarantees measurement accuracy.
In order to achieve the above purpose, the utility model adopts the technical scheme that: the utility model provides a cylinder diameter measurement system based on line structure light, includes that mounting plate, line laser instrument, image acquisition device and symmetry set up two supports at the mounting plate top, line laser instrument and image acquisition device set up the top at two supports respectively, mounting plate's top is provided with slide rail and is located two supports between, slide on the slide rail and be provided with the slip dolly that is used for placing the cylinder work piece that awaits measuring, the bottom of slip dolly be provided with slide rail assorted slider, the head end and the end of slide rail all are provided with and are used for carrying out spacing stopper to the slip dolly.
Furthermore, a V-shaped groove for placing the cylindrical workpiece to be detected is formed in the top end of the sliding trolley.
Furthermore, the image acquisition device is detachably mounted on the corresponding support through a mounting disc.
Further, image acquisition device and mounting disc fixed connection and image acquisition device are located the one side that the support was kept away from to the mounting disc, and two spouts have been seted up to the symmetry on the mounting disc, all wear to be equipped with in each spout one with support threaded connection's T type bolt.
Further, two spouts all be the arc and intrados face to face setting between them.
Furthermore, the central axes of the slide rail and the two supports are in the same vertical plane.
Further, the image acquisition device is a camera connected with the upper computer.
Compared with the prior art, the beneficial effects of the utility model are that: the utility model discloses do not need the measurement personnel to adopt slide caliper to measure, can not receive the influence of measurement personnel's proficiency, measurement operation method etc. measurement accuracy is high, and is applicable to continuous rapid survey, and degree of automation is high.
Drawings
FIG. 1 is a schematic diagram of a line structured light based cylinder diameter measurement system;
FIG. 2 is a top view of FIG. 1;
FIG. 3 is a schematic diagram showing the positional relationship between the sliding carriage and the cylindrical workpiece to be measured;
FIG. 4 is a schematic structural view of a mounting plate;
FIG. 5 is a flow chart illustrating a measurement method using a line structured light based cylinder diameter measurement system;
FIG. 6 is a schematic diagram of the physical coordinate system of the image, the pixel coordinate system of the image, and the modeling of the camera coordinate system;
FIG. 7 is a schematic diagram of the creation of a model with O as the center;
FIG. 8 is a schematic diagram of the creation of a virtual plane perpendicular to the axis of the cylinder under test;
the labels in the figure are: 1. support, 2, line laser instrument, 3, stopper, 4, slide rail, 5, slider, 6, slip dolly, 7, the cylinder work piece that awaits measuring, 8, mounting panel, 9, image acquisition device, 10, mounting disc, 11, spout, 12, T type bolt.
Detailed Description
In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the following will combine the drawings in the present invention to clearly and completely describe the technical solution in the embodiments of the present invention, and obviously, the described embodiments are some embodiments of the present invention, rather than all embodiments, based on the embodiments in the present invention, all other embodiments obtained by a person of ordinary skill in the art without creative work belong to the protection scope of the present invention.
The utility model provides a cylinder diameter measurement system based on line structure light, as shown in figure 1 and figure 2, set up two supports 1 at the mounting plate top including mounting plate 8, line laser instrument 2, image acquisition device 9 and symmetry, line laser instrument 2 and image acquisition device 9 set up respectively on the top of two supports 1, mounting plate 8's top is provided with slide rail 4 and is located two supports 1 between, slide rail 4 goes up to slide and is provided with the slip dolly 6 that is used for placing the cylinder work piece 7 that awaits measuring, the bottom of slip dolly 6 be provided with slide rail 4 assorted slider 5, the head end and the end of slide rail 4 all are provided with and are used for carrying out spacing stopper 3 to slip dolly 6.
Further optimizing the scheme, as shown in fig. 3, a V-shaped groove for placing the cylindrical workpiece 7 to be measured is formed at the top end of the sliding trolley 6.
Further optimizing this scheme, image acquisition device 9 passes through mounting disc 10 detachable and installs on its support 1 that corresponds.
Further optimize this scheme, image acquisition device 9 and mounting disc 10 fixed connection and image acquisition device 9 are located one side that support 1 was kept away from to mounting disc 10, as shown in fig. 4, two spouts 11 have been seted up to the symmetry on the mounting disc 10, all wear to be equipped with in each spout 11 one with support 1 threaded connection's T type bolt 12.
Further optimize this scheme, two spout 11 all be the arc and intrados face relative setting between them.
Further optimize this scheme, the slide rail 4 with the central axis of two support 1 three in same vertical plane.
Further optimizing the scheme, the image acquisition device 9 is a camera connected with an upper computer.
Use the utility model discloses a measurement method of cylinder diameter measurement system based on line structure light, including following step:
the method comprises the following steps: placing a cylindrical workpiece 7 to be measured in a V-shaped groove formed in a sliding trolley 6;
step two: starting the line laser 2 and sliding the sliding trolley 6 back and forth in the sliding rail 4 to enable a laser surface emitted by the line laser 2 to intersect with the section of the to-be-measured cylindrical workpiece 7 to form a light bar;
step three: adjusting the T-shaped bolt 12 to separate the mounting disc 10 from the support 1, then rotating the mounting disc 10 to enable the light bars generated in the step two to be positioned in the visual field of the image acquisition device 9, and then adjusting the T-shaped bolt 12 to fix the mounting disc 10 on the support 1;
step four: acquiring picture information through an image acquisition device 9 and uploading the acquired picture information to an upper computer;
step five: and the upper computer processes the acquired picture information to obtain the diameter of the cylindrical workpiece 7 to be measured.
Further optimizing this scheme, the process that the host computer handled the picture information of gathering in order to obtain the diameter of the cylinder work piece 7 that awaits measuring includes the following steps:
the method comprises the following steps: preprocessing the collected picture information by adopting a filtering and morphological processing method to ensure that the light bars are complete and accurate at the boundary;
step two: extracting the centers of the light bars and fitting the centers of the light bars;
step three: and calculating the diameter of the cylindrical workpiece to be measured according to the fitted ellipse.
The following describes the processing flow of the upper computer in detail:
the principle of the utility model is as follows: the diameter of a cylindrical workpiece is measured by a line structured light method, the line structured light method uses a laser triangle method as a basic measurement principle, a laser surface emitted by a line laser 2 is projected onto the surface of the cylindrical workpiece 7 to be measured, the laser surface intersects with the cross section of the position of the cylindrical workpiece 7 to be measured to form a light bar, the laser is used as a carrier for transmitting information, a high-resolution camera is used for collecting images, a mathematical model is established, the position of a pixel point of the light bar in a world coordinate system can be calculated through system calibration, and the diameter of the cylindrical workpiece to be measured can be obtained.
In the online structured light measurement method, in order to find out the pixel coordinates of the light bar points and the corresponding specific coordinates in the world coordinate system, a proper measurement model needs to be established. In the on-line structured light measurement method, common mathematical models are as follows: analytic geometric model, artificial neural network model and aperture imaging model, the utility model discloses when using, use the aperture imaging model most commonly used.
Firstly, an image physical coordinate system, an image pixel coordinate system and a camera coordinate system are established, the model principle is as shown in FIG. 6,
1. physical coordinate system of image
O-xy is an image physical coordinate system, and an intersection O of the camera optical axis and the image plane taken by the camera is taken as an origin, and O is also an intersection of the camera optical axis and the image plane, and is also called a principal point.
2. Image pixel coordinate system
The image pixel coordinate system takes the upper left corner of the image captured by the camera as the origin of coordinates, and (u, v) represents the column coordinates and row coordinates of a point on the image.
3. Camera coordinate system
Oc-XcYcZcThe coordinate system is a camera coordinate system with a camera optical center OcIs the origin, OcZcIs an optical axis, OcxcAnd OcYcParallel to the x and y axes of the image physical coordinate system, respectively.
4. World coordinate system
Ow-XwYw Z wThe coordinate system is a world coordinate system, and the position needs to be selected according to a system calibration method and system measurement.
Let a point P in space have coordinates in the world coordinate system of (x)w，yw，zw) The coordinate in the camera coordinate system is (x)c，yc，zc) The coordinates in the image pixel coordinate system are (u, v), (u, v) and (x)c，yc，zc) The transformation relationship between the two is as follows:
calculating (x) from (u, v) using the above formulac，yc，zc) Then, no unique solution can be obtained. Therefore, in the on-line structured light measurement method, light plane constraint needs to be added, and points on the light bar meet both the pinhole imaging model and the light plane constraint condition.
Let the equation of the light plane in the camera coordinate system be axc+byc+czcWhen + d is 0, this equation and the formula (1) are combined to obtain:
from this, (u, v) and (x) can be obtainedc，yc，zc) One-to-one correspondence between points P and P, the coordinates (x) of the points P in the camera coordinate systemc，yc，zc) And world coordinatesCoordinate under system (x)w，yw，zw) The relationship between them is as follows:
r and T are respectively a rotation matrix and a translation matrix when the camera coordinate system is converted into a world coordinate system, so that the coordinate value (x) of the point in the world coordinate system can be directly calculated from (u, v)w，yw，zw)。
Secondly, the specific operation method of the present invention is shown in fig. 5, and the specific method used is described in detail below with reference to fig. 5:
1. a cylinder diameter measuring system based on line structured light is designed by mainly adopting an inclined-entering laser triangulation method, and is built according to the used method and the convenience, the practicability and the operability of cylinder measurement;
2. by utilizing a sliding rail 4 and a sliding block 5 mechanism, the sliding trolley 6 can horizontally move along the sliding rail 4 so as to measure the diameters of different sections of the cylindrical workpiece to be measured;
3. in order to make the collected edges of the light bars complete and accurate, preprocessing is carried out by adopting a filtering and morphological processing method, and then the centers of the light bars are fitted according to a sub-pixel level edge detection algorithm (a method improved based on a gray scale gravity center method).
The method takes the gray scale gravity center of the light strip as the central point of the light strip and uses the idea of weighted average. The coordinate of the central pixel of the light bar extracted from the ith column of the image is (u)id，vid) And the gray value of the light bar point on the ith column and the jth row is G (j, i), the following relationship exists:
but because arc striation luminance distributes unevenly, and the striation center effect of drawing with grey scale gravity center method is unsatisfactory, the utility model discloses improve to above-mentioned condition, take out earlier to the image and open the operation, get rid of the burr around the striation, the border of level and smooth image uses Zhang to divide the algorithm fast again and refines the image, continues to use grey scale gravity center method to handle the image after refining at last, obtains the striation center that the precision is relatively high.
The striation central line that obtains is fitted, because there is certain contained angle in linear laser incident direction and the cylinder that awaits measuring, makes the striation central line that obtains be an ellipse through the fitting, in order to solve this problem, the utility model provides a cylinder diameter measurement algorithm based on centre of a circle restraint establishes the model that uses O as the centre of a circle, as shown in fig. 7, A, B, C, D are the point on the circle, and H is the nodical of AC and BD, can according to the geometric relation of circle:
AH×CH＝BH×DH＝r2-OH2 (5)
wherein r is the radius of the circle, and the coordinate of the point O at the center of the circle is (x)0y0) The coordinates of the points A, B, C and D are respectively (x)1，y1)，(x2，y2)，(x3，y3)，(x4，y4) The coordinates of the points A, B, C and D are used to obtain the coordinates (x) of the point H5，y5)。
In order to improve the measurement accuracy, a virtual plane perpendicular to the axis of the cylinder to be measured is established, as shown in FIG. 8, where π2Is a virtual plane perpendicular to the MN, PiIs the measured point on the cylinder, QiPoint is PiDotted at pi2Projection on the surface, point Q on arc cd on the virtual planeiThe average is 4 areas, the number of points on each area is n, and A, B, C and D respectively correspond to the points of the 4 areas. Let AiIs the ith point, then BiAt point i + n, CiAt point i +2n, DiIs the (i + 3) th point. Will QiSubstituting the local coordinates of the points into equation (5) can obtain an objective function for optimizing the center point:
where r is an estimate of the radius of the cylinder.
In fig. 7, L is a chord on the circle, F is the midpoint OF the chord, OF ≠ L, i.e., OF · L ═ 0. The objective function for optimizing the center point can be further expressed as:
and (6) and (7) are combined, and the optimization function of the optimization center point is obtained as follows:
solving the minimum value of the formula (8) is a nonlinear optimization problem, solving the optimal solution of the objective function to obtain the optimized circle center OcIs provided with OcHas the coordinates of (x)c，yc) Introducing OcAnd QiAnd (3) substituting the local coordinates of the points into the formula (9) to obtain the diameter of the measured cylinder:
wherein N is 4 × N.
The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
Claims (7)
1. The utility model provides a cylinder diameter measurement system based on line structure light, includes mounting plate (8), line laser (2), image acquisition device (9) and symmetry set up two supports (1) at the mounting plate top, its characterized in that: line laser ware (2) and image acquisition device (9) set up respectively on the top of two supports (1), the top of mounting plate (8) is provided with slide rail (4) and slide rail (4) are located two supports (1) between, slide on slide rail (4) and be provided with slip dolly (6) that are used for placing cylinder work piece (7) that await measuring, the bottom of slip dolly (6) be provided with slide rail (4) assorted slider (5), the head end and the end of slide rail (4) all are provided with and are used for carrying out spacing stopper (3) to slip dolly (6).
2. The line structured light based cylinder diameter measurement system of claim 1, wherein: the top end of the sliding trolley (6) is provided with a V-shaped groove for placing a cylindrical workpiece (7) to be tested.
3. The line structured light based cylinder diameter measurement system of claim 1, wherein: the image acquisition device (9) is detachably mounted on the corresponding support (1) through a mounting disc (10).
4. The line structured light based cylinder diameter measurement system of claim 3, wherein: image acquisition device (9) and mounting disc (10) fixed connection and image acquisition device (9) are located one side that support (1) were kept away from in mounting disc (10), and two spout (11) have been seted up to the symmetry on mounting disc (10), all wear to be equipped with in each spout (11) one with support (1) threaded connection's T type bolt (12).
5. The line structured light based cylinder diameter measurement system of claim 4, wherein: the two sliding grooves (11) are arc-shaped, and the inner arc surfaces of the two sliding grooves are arranged oppositely.
6. The line structured light based cylinder diameter measurement system of claim 1, wherein: the central axes of the slide rail (4) and the two brackets (1) are in the same vertical plane.
7. The line structured light based cylinder diameter measurement system of claim 1, wherein: the image acquisition device (9) is a camera connected with an upper computer.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201920274676.8U CN209877895U (en) | 2019-03-05 | 2019-03-05 | Cylinder diameter measurement system based on line structured light |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201920274676.8U CN209877895U (en) | 2019-03-05 | 2019-03-05 | Cylinder diameter measurement system based on line structured light |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN209877895U true CN209877895U (en) | 2019-12-31 |
Family
ID=68953907
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201920274676.8U Active CN209877895U (en) | 2019-03-05 | 2019-03-05 | Cylinder diameter measurement system based on line structured light |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN209877895U (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109708583A (en) * | 2019-03-05 | 2019-05-03 | 洛阳德晶智能科技有限公司 | A kind of cylinder diameter measuring system and measurement method based on line-structured light |
| CN113029017A (en) * | 2021-01-22 | 2021-06-25 | 中铁大桥局集团有限公司 | Acceptance equipment and acceptance method for columnar reinforcement cage |
| CN114322802A (en) * | 2021-12-30 | 2022-04-12 | 苏州中科行智智能科技有限公司 | Line diameter measuring method based on 3D line laser camera |
| CN115077423A (en) * | 2022-06-16 | 2022-09-20 | 西南交通大学 | Portable high-speed turnout detection trolley and method based on line laser technology |
| CN115541598A (en) * | 2022-08-24 | 2022-12-30 | 深圳市二郎神视觉科技有限公司 | Automobile appearance detection method, device and system |
-
2019
- 2019-03-05 CN CN201920274676.8U patent/CN209877895U/en active Active
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109708583A (en) * | 2019-03-05 | 2019-05-03 | 洛阳德晶智能科技有限公司 | A kind of cylinder diameter measuring system and measurement method based on line-structured light |
| CN113029017A (en) * | 2021-01-22 | 2021-06-25 | 中铁大桥局集团有限公司 | Acceptance equipment and acceptance method for columnar reinforcement cage |
| CN114322802A (en) * | 2021-12-30 | 2022-04-12 | 苏州中科行智智能科技有限公司 | Line diameter measuring method based on 3D line laser camera |
| CN115077423A (en) * | 2022-06-16 | 2022-09-20 | 西南交通大学 | Portable high-speed turnout detection trolley and method based on line laser technology |
| CN115077423B (en) * | 2022-06-16 | 2023-03-14 | 西南交通大学 | Portable high-speed turnout detection trolley and method based on line laser technology |
| CN115541598A (en) * | 2022-08-24 | 2022-12-30 | 深圳市二郎神视觉科技有限公司 | Automobile appearance detection method, device and system |
| CN115541598B (en) * | 2022-08-24 | 2024-05-14 | 深圳市二郎神视觉科技有限公司 | Automobile appearance detection method, device and system |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN209877895U (en) | Cylinder diameter measurement system based on line structured light | |
| CN106705897B (en) | Method for detecting defects of arc-shaped glass panel for curved-surface electronic display screen | |
| CN201974160U (en) | Device for measuring three-dimensional shape of structured light | |
| Li et al. | Automatic recalibration of an active structured light vision system | |
| CN103047944B (en) | Three-dimensional object measuring method and device | |
| CN103615980B (en) | Method and system for measuring parameters of round holes in plate | |
| CN105784716B (en) | Friction plate Quality Inspection System | |
| CN102607977B (en) | Abrasion in-situ measuring device based on digital image processing and method | |
| CN109612390A (en) | Large-size workpiece automatic measuring system based on machine vision | |
| CN106017350A (en) | Machine-vision-based rapid detection device and detection method for medium and small module gears | |
| CN101458072A (en) | Three-dimensional contour outline measuring set based on multi sensors and measuring method thereof | |
| CN109405755B (en) | Large-size pipe plate aperture and pitch measuring device and measuring method | |
| CN101038155A (en) | Apparatus and method for detecting surface shape of aspheric surface | |
| Xia et al. | An accurate and robust method for the measurement of circular holes based on binocular vision | |
| CN109520436A (en) | A kind of butterfly spring three-dimensional dimension automatic measurement system and its measurement method based on machine vision | |
| CN101793840A (en) | Diamond cutting parameter measurement method and measuring device | |
| Duan et al. | High precision edge detection algorithm for mechanical parts | |
| CN110375674A (en) | A kind of vision detection system of precision manufactureing equipment | |
| CN211042086U (en) | Contact net geometric parameters dynamic detector based on binocular 3D vision | |
| CN103884294B (en) | The method and its device of a kind of infrared light measuring three-dimensional morphology of wide visual field | |
| CN202304767U (en) | Three-dimensional outline measurement device based on multiple sensors | |
| DE69718988T2 (en) | System for measuring the characteristics of an object | |
| Wan et al. | Extraction and segmentation method of laser stripe in linear structured light scanner | |
| CN110174055A (en) | A kind of 3D vision detection device of high precision planeness detection | |
| CN112361989B (en) | Method for calibrating parameters of measurement system through point cloud uniformity consideration |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant |