CN115420212A

CN115420212A - On-line detection system for out-of-roundness of cylinder

Info

Publication number: CN115420212A
Application number: CN202210971856.8A
Authority: CN
Inventors: 镇方雄; 邓岚清
Original assignee: Hubei University of Science and Technology
Current assignee: Hubei University of Science and Technology
Priority date: 2022-08-11
Filing date: 2022-08-11
Publication date: 2022-12-02

Abstract

The invention discloses an online detection system for out-of-roundness of a cylinder, which comprises a translation and rotation device and an optical imaging device, wherein the translation and rotation device comprises: at least 2 link joints, baffle, gyration belt with be detected the cylinder, the link joint parallels to a plane is constituteed on the ground side by side, optical imaging device includes: the device comprises a detected cylinder, a parallel light source, a baffle, a first reflecting mirror, a second reflecting mirror and a camera, wherein the parallel light source is arranged in the baffle and emits light to the rotation direction of a rotary belt, the first reflecting mirror is fixed on the reverse side of the baffle light source, the included angle between the reverse side of the baffle light source and the rotary belt is beta, the second reflecting mirror is arranged on the left side in parallel, and the camera is arranged in the rotation direction of the rotary belt in the translation of the second reflecting mirror. The invention has the beneficial effect that the translation and rotation device and the optical imaging device are mutually matched, so that the detected cylinder can be imaged in a camera at different angles when rotating.

Description

On-line detection system for out-of-roundness of cylinder

Technical Field

The invention relates to an online detection system for a cylindrical product in the packaging detection industry, in particular to an online detection system and method for out-of-roundness of a cylinder, and belongs to the field of surface defect detection.

Background

Out-of-roundness refers to the difference between the maximum and minimum diameters of a cylinder in the same cross-section, and is also referred to as ovality or out-of-roundness. Out-of-round therefore means that there is a significant difference between the largest projection and the largest depression on all cross-sections of the cylinder. According to the definition of out-of-round, the inspection of out-of-round of a cylinder is mainly explored from the aspects of the upper edge of the cylinder, the outer surface of the cylinder, the lower edge of the cylinder, a plurality of cross sections and the like.

Referring to fig. 4, the inspection plan in different expressions has advantages and disadvantages:

principle explanation:

out-of-roundness = overall ellipse + undulation over a certain large range + bumpy feel over a small range, and is very complex in any case.

Background:

in the process of high-speed running of a production line, cylinder products (such as glass bottles) cannot perform fixed-point rotation on each cylinder and recognize the surface defects of the cylinders in a visual scanning mode, and only a non-contact optical scheme can be adopted to acquire surface defect information.

The surface of the cylinder is undulated, which is a very common defect. On the one hand, the surface is fluctuated, so that a production line can clamp a bottle in the motion process, on the one hand, the situation that the fluctuation degree is too large to cause the bottle body to be too thin and easy to break exists, and on the one hand, the surface is fluctuated and the label cannot be tightly attached to the surface to cause falling and folding. In addition, the surface of the cylinder fluctuates, which is a continuous state and a contrast state, and how to continuously and contrastively detect the cylinder is a very headache problem.

The prior art at present has patent application number 201820737903.1, which is an online rotary shooting device for cylindrical appearance detection, and comprises a camera, a lens, a first plane mirror, a second plane mirror, a rotary table and an annular light source, wherein the first plane mirror and the second plane mirror are arranged on the rotary table, a cylindrical sample is located under the rotary table, and the annular light source is arranged above the cylindrical sample and used for illuminating the cylindrical sample and adjusting the angles of the first plane mirror and the second plane mirror, so that the image of the cylindrical sample sequentially enters the lens after being reflected by the first plane mirror and the second plane mirror. It cannot perform line production.

The Chinese patent application publication number CN 114459375A has the following invention name: an on-line detection method for cylinder out-of-roundness comprises the steps of decomposing the circumferential surface of a to-be-detected piece into a plurality of strip-shaped local images through at least one optical flattening mechanism, and then collecting all the local images into the same plane by using an image-capturing terminal to form an image-image cluster of the circumferential surface corresponding to the to-be-detected piece; acquiring an image-shadow cluster of a standard part in the same way, and comparing and analyzing the image-shadow cluster of the standard part and the image-shadow cluster of the to-be-detected part to judge the out-of-roundness condition of the to-be-detected part; the optical flattening mechanism comprises a plurality of reflectors and a light source, the light source can enable the part to be detected to emit light, and the image capturing terminal obtains an image which is emitted by the part to be detected and reflected once by the reflectors. According to the method, each optical flattening mechanism comprises eight reflectors, every four reflectors form a group, and if high-definition pictures are required, the denser the number of the reflectors is, the better the detection effect is, so that the higher the cost is.

Disclosure of Invention

Therefore, the online detection system for the out-of-roundness of the cylinder, which is provided by the invention, has a good detection effect and a simple structure.

The scheme provided by the invention is as follows:

an on-line detection system for the out-of-roundness of a cylinder comprises a translation and rotation device and an optical imaging device,

the translation and rotation device includes: the device comprises at least 2 chain plates, a rotary belt and a detected cylinder, wherein the chain plates are parallel to the ground to form a plane, the rotary belt is perpendicular to the plane of the chain plates and is arranged on the chain plates, an angle alpha is formed in the parallel direction of the obliquely-crossing chain plates, the rotary belt is provided with a baffle, and one side of the baffle is fixed on the rotary belt;

the optical imaging device includes: the device comprises a detected cylinder, a parallel light source, a baffle, a first reflecting mirror, a second reflecting mirror and a camera, wherein the parallel light source is arranged on the baffle in a built-in mode and emits light to the rotating direction of a rotating belt;

a rotation belt of the translation rotating device drives a baffle to push the detected cylinder to move, the detected cylinder is driven to rotate under the driving of different speeds of a chain plate, and a parallel light source of the optical imaging device forms a spectrum in a camera through secondary reflection imaging on a reflector I and a reflector II to detect the out-of-roundness of the cylinder on line.

Furthermore, the imaging length of the second reflecting mirror is matched with the width of a chain plate and the length of a belt.

Further, the number of the chain plates is 3, the second speed of the chain plate is 1.5 times of the first speed of the chain plate, and the third speed of the chain plate is 1.5 times of the second speed of the chain plate.

Furthermore, the surface of the rotating belt is smooth and flat and is light-tight.

Furthermore, the baffle and the reflector form a right-angle equilateral triangular prism, beta =45 degrees, and the right-angle edge of the triangular prism is fixed on the rotary belt and is internally provided with a parallel light source which emits light towards the rotation direction of the belt.

Further, the rotary belt is arranged on the chain plate perpendicular to the plane of the chain plate, and the inclined span of the three chain plates forms an angle alpha with the parallel direction of the chain plate, wherein the angle alpha =45 degrees.

Furthermore, the second reflecting mirror is perpendicular to the direction parallel to the chain plate.

Furthermore, the second reflecting mirror is made of ground glass, the surface of the second reflecting mirror is frosted, and the camera is positioned right opposite to the second reflecting mirror and can shoot a projection map at the maximum visual angle.

The invention has the beneficial effects that:

1. the camera is preferably placed horizontally, and a sufficient area can be seen by projecting a picture on the second mirror (ground glass mirror) and then using the camera view angle.

2. Translation rotary device and optical imaging device mutually support, just can make detected cylinder synchronous motion when the rotation, can be under the camera formation of image under different angles.

3. The imaging length of the second reflective mirror is matched with the width of the chain plate and the length of the belt, so that the camera can finish imaging for many times.

4. The second speed of the chain plate is 1.5 times of the first speed of the chain plate, and the third speed of the chain plate is 1.5 times of the second speed of the chain plate, so that the cylinder 6 to be detected can rotate twice by itself to achieve 180-270 degrees of rotation.

The judging method comprises the following steps:

1. assuming that the effective area projected on the second mirror (ground glass mirror) is 80%, the shadow and the light leakage of the whole cylinder can be basically determined by continuously shooting images (assuming 20 pictures) by the camera and adding the motion speed recognized by the encoder projection.

2. Through 20 pieces of analysis, one part is an exposure area, and the black dark area of one part of the cylinder is added with a small part of out-of-circle light leakage area, so that the calculation of the black dark area boundary can calculate whether the diameter of the cylinder is too large or too small, and whether the diameter of the 20 inner cylinders still has ellipses and deformation.

3. The light leakage area actually is the enlarged out-of-round degree, and the size of the out-of-round degree in each photo can be accurately found through calculation of the light leakage area.

Drawings

FIG. 1 is a schematic diagram of an online detection system for out-of-roundness of a cylinder according to the present invention;

FIG. 2 is a schematic view of a translational rotary device of the present invention;

FIG. 3 is a schematic view of an optical imaging apparatus of the present invention;

FIG. 4 is a schematic illustration of a representation of the present invention relating to out-of-roundness;

wherein, 1-link joint I; 2-link plate two; 3-link joint three; 4-a baffle plate; 5-rotating the belt; 6-cylinder to be measured; 7-a collimated light source; 8, a first reflector; 9-a second reflector; 10-camera.

Detailed description of the preferred embodiments

The present invention is described in more detail below by way of examples, which are illustrative only, and the scope of the present invention is not limited by these examples.

Referring to fig. 1, an on-line detection system for out-of-roundness of a cylinder is composed of a translation and rotation device and an optical imaging device.

Referring to fig. 2, the translation and rotation device mainly comprises a measured cylinder 6, a plurality of chain plates, a revolving belt 5 and the like; a detected cylinder 6 on the chain plate is transited from a first chain plate 1 to a third chain plate 3 through a rotary belt 5; and then proceeds to the next process. Wherein, the rotary belt 5 and the chain plate are installed in an alpha-angle slant way in the parallel direction, and the detection of the full surface waviness of the cylinder is realized.

The link joint 1, the link joint 2 and the link joint 2 are set at different speeds, and the following phenomena can be found:

when the cylinder 6 to be measured moves towards the chain plate 2 from the chain plate 1, the cylinder is completely driven by the rotary belt to be pushed.

Due to the speed difference between the

chain plates

1 and 2, the chain plate 2 rubs the bottom of the cylinder to realize the self-rotation of the cylinder, and the rotation of the cylinder is close to the rotation of the belt.

Due to the 1.5-fold difference between the speed of the first chain plate 1 and the speed of the second chain plate 2, the rotation angle of the detected cylinder 6 can be between 180 and 270 degrees. The cylinder rotates against the belt (smooth and hard) and rotates 180-270.

Referring to fig. 3, the optical imaging device is composed of a belt baffle 4, a parallel light source 7, a first reflector 8, a second reflector 9, a camera 10 and the like; a plurality of belt baffles 4 are vertically and uniformly arranged on a rotary belt 5, led parallel light sources 7 are embedded in the advancing surface direction of the belt baffles 4, and the starting points and the lengths of the parallel light sources 7 are matched for adapting to the diameter of a cylinder; the Led parallel light source 7 is tightly attached to the rotary belt 5; each belt baffle 4, the parallel light source 7 and the first reflector 8 of the rotary belt 5 form a small unit; an included angle beta is formed between the first reflecting mirror 8 and the rotating belt 5; each unit of the rotating belt 5 ensures that the belt baffle 4 and the cylinder 6 to be measured are both in the same. 4, through embedding the led parallel light source in the vertical plane, and the cylinder rotates along the belt in the advancing process, thereby finding out that

If the surface of the measured cylinder 6 is fluctuated and concave-convex, light leaks from the measured cylinder 6 at the position of the rotary belt 5, and is reflected by the first reflecting mirror 8, so that a little light can be irradiated upwards. The imaging length of the second reflective mirror 9 is matched with the width of the chain plate and the imaging of the lens of the camera 10.

If the surface of the measured cylinder 6 is fluctuated and concave-convex, the other side of the measured cylinder 6 can form a fluctuated edge phenomenon, and a large amount of light rays are upwards irradiated at the edge of the cylinder through reflection of the first reflector 8.

Because the measured cylinder 6 can rotate 180-270 degrees, the edge profiles of all cylinders (the belt close attaching surface and the opposite side surface) can be known by collecting the reflection areas for multiple times, and the out-of-roundness of the cylinders can be known through model construction.

If the measured cylinder 6 is an ellipse, no light leaks from the close contact surface of the belt, and only light irradiates the opposite side surface. The maximum outer diameter and the minimum diameter of the ellipse can be known through the unilateral edge profile, and finally the out-of-roundness is known.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention, and the scope of the present invention is not limited thereto, and any modifications, equivalents and improvements made by those skilled in the art within the technical scope of the present invention are intended to be included in the scope of the present invention.

Claims

1. An on-line detection system for the out-of-roundness of a cylinder is characterized by comprising a translation and rotation device and an optical imaging device,

the translational rotating device comprises: the detection device comprises at least 2 chain plates, a rotary belt (5) and a detected cylinder (6), wherein the chain plates are parallel to the ground to form a plane, the rotary belt (5) is perpendicular to the plane of the chain plates and is arranged on the chain plates and obliquely spans the parallel direction of the chain plates to form an alpha angle, a baffle (4) is arranged on the rotary belt (5), and one side of the baffle (4) is fixed on the rotary belt (5);

the optical imaging apparatus includes: the detection device comprises a detected cylinder (6), a parallel light source (7), a baffle (4), a first reflecting mirror (8), a second reflecting mirror (9) and a camera (10), wherein the parallel light source (7) is arranged in the baffle (4) and emits light to the rotating direction of a rotary belt (5), the first reflecting mirror (8) is fixed on the reverse side of the baffle light source direction and has an included angle beta with the rotary belt (5), the second reflecting mirror (9) is arranged on the left side in parallel, and the camera (10) is arranged in the rotating direction of the rotary belt translated by the second reflecting mirror (9);

a rotary belt (5) of the translation rotating device drives a baffle (4) to push a detected cylinder (6) to move, the detected cylinder (6) is driven to rotate under the driving of different speeds of chain plates, and a parallel light source (7) of the optical imaging device is reflected and imaged on a camera for the second time on a first reflecting mirror (8) and a second reflecting mirror (9) to form a spectrum to detect the out-of-roundness of the cylinder on line.

2. The on-line detection system for the out-of-roundness of the cylinder as claimed in claim 1, wherein the imaging length of the second reflecting mirror (9) is adapted to the width of the link plate and the length of the revolving belt (5).

3. The system of claim 1, wherein the number of the chain plates is 3, wherein the speed of the second chain plate (2) is 1.5 times of the speed of the first chain plate (1), and the speed of the third chain plate (3) is 1.5 times of the speed of the second chain plate (2).

4. The system for the on-line detection of the out-of-roundness of a cylinder according to claim 1, wherein the surface of the rotating belt (5) is smooth, flat and opaque.

5. The system for on-line detection of the out-of-roundness of a cylinder according to claim 1, wherein the baffle (4) and the reflector (1) form a right-angled equilateral triangular prism, β =45 °, the right-angled edges of the triangular prism are fixed to the revolving belt and are provided with a parallel light source (7) emitting light in the direction of rotation of the belt.

6. An on-line cylinder out-of-roundness detection system according to claim 1, wherein said revolving belt (5) is installed on said link plate perpendicularly to the link plate plane and is inclined across three link plates at an angle α =45 ° from the link plate parallel direction.

7. The on-line detection system for the out-of-roundness of the cylinder as claimed in claim 1, wherein the second reflecting mirror (9) is perpendicular to the direction parallel to the link plate.

8. The on-line detection system for the out-of-roundness of the cylinder as claimed in claim 1, wherein the second reflecting mirror (9) is ground glass, the camera is positioned right opposite to the second reflecting mirror (9), and the imaging spectrum is acquired at the maximum viewing angle.