CN114355379A - Online laser measurement system and method thereof - Google Patents

Abstract

The invention relates to an on-line laser measurement system, which is used for measuring the wall thickness deflection between two symmetrical points of the same section of a glass tube and comprises the following components: the first optical assembly and the third optical assembly are arranged above the glass tube conveying roller way, and the second optical assembly and the fourth optical assembly are arranged below the glass tube conveying roller way; laser beams emitted by the optical assemblies are reflected by the glass tube, and then strip-shaped light spots are formed on the image processing assembly respectively. The system and the method can accurately measure the wall thickness deviation between two symmetrical points of the same section of the glass tube in the production process without stopping, and the measured glass tube is not damaged by adopting a non-contact measuring method, so that the quality and the production efficiency of products are improved.

Description

Online laser measurement system and method thereof

Technical Field

The invention relates to the technical field of dynamic measurement, in particular to an online laser measurement system and method.

Background

In the process of producing the glass tube by the horizontal method, the wall thickness deviation between two symmetrical points of the same section of the produced glass tube needs to be dynamically detected and monitored so as to ensure the uniformity of the wall thickness of the glass tube. At present, an optical sampling method is usually adopted for dynamically measuring the wall thickness deviation between two symmetrical points of the same section of a glass tube, and the traditional optical sampling method generally has two forms: the method is characterized in that the wall thickness deflection between two symmetrical points with the same section is detected by utilizing the imaging projection of a glass tube, and the wall thickness deflection of the tube is detected by utilizing the reflection and refraction of laser spots on the inner surface and the outer surface of the wall of the glass tube. The imaging projection generally has high assembly requirements on a detection system and is only suitable for off-line inspection of finished glass tube products; in the production process, dynamic detection is usually performed by reflecting and refracting laser spots on the inner and outer surfaces of the glass tube wall. However, with the laser spot reflection mode, the position of the reflected light point is easy to deviate due to the fact that the glass tube has an arc in the radial direction, the intensity and the moving direction position of the reflected light can be changed, the measurement result is affected, and the measurement error is large, so that the technical difficulty in dynamically measuring the wall thickness deviation between two symmetrical points of the same cross section of the glass tube is large.

Disclosure of Invention

The invention aims to provide a system and a method for online laser measurement, aiming at the defects in the prior art.

In order to achieve the purpose, the invention adopts the technical scheme that:

providing an on-line laser measurement system for measuring wall thickness deviation between two symmetrical points of a same cross section of a glass tube, comprising: the optical device comprises a first optical assembly, a second optical assembly, a third optical assembly, a fourth optical assembly and an image processing assembly;

the first optical assembly and the third optical assembly are arranged above a conveying roller way of the glass tube, the second optical assembly and the fourth optical assembly are arranged below the conveying roller way of the glass tube, the first optical assembly and the second optical assembly are arranged on a vertical surface, the first optical assembly and the third optical assembly are arranged on a horizontal surface, the second optical assembly and the fourth optical assembly are arranged on another horizontal surface, and the third optical assembly and the fourth optical assembly are arranged on another vertical surface;

and laser beams emitted by the first optical assembly, the second optical assembly, the third optical assembly or the fourth optical assembly are reflected by the glass tube to form a strip-shaped light spot on the image processing assembly.

Preferably, the first optical assembly comprises: the device comprises a first laser light source, a first beam expanding lens and a first rotating mirror;

after being expanded by the first beam expanding lens, the laser beam emitted by the first laser light source is reflected by the first rotating mirror, so that the laser beam forms an exit angle of 45 degrees with the horizontal plane.

Preferably, the second optical assembly comprises: the second laser light source, the second beam expanding lens and the second rotating mirror;

and after the laser beam emitted by the second laser light source is expanded by the second beam expanding lens, the laser beam is reflected by the second rotating mirror, so that the laser beam forms an exit angle of 45 degrees with the horizontal plane.

Preferably, the third optical assembly comprises: a third laser light source, a third beam expanding lens and a third rotating mirror;

and after being expanded by the third beam expanding lens, the laser beam emitted by the third laser light source is reflected by the third rotating mirror, so that the laser beam forms an exit angle of 45 degrees with the horizontal plane.

Preferably, the fourth optical assembly comprises: the fourth laser light source, the fourth beam expanding lens and the fourth rotating mirror;

and after being expanded by the fourth beam expanding lens, the laser beam emitted by the fourth laser light source is reflected by the fourth rotating mirror, so that the laser beam forms an exit angle of 45 degrees with the horizontal plane.

Preferably, the image processing assembly comprises: the system comprises a first charge coupled device image sensor, a second charge coupled device image sensor, an image collector and a signal processor;

the first charge coupled device image sensor and the second charge coupled device image sensor are respectively electrically connected with the image collector, and the image collector is electrically connected with the signal processor.

Preferably, the laser beams emitted by the first optical assembly and the third optical assembly form a strip-shaped light spot on the first ccd image sensor after being reflected by the glass tube.

Preferably, the laser beams emitted by the second optical assembly and the fourth optical assembly form a strip-shaped light spot on the second ccd image sensor after being reflected by the glass tube.

The second aspect of the present invention provides an on-line laser measurement method using the system, which is used for measuring the wall thickness deviation between two symmetrical points of the same cross section of a glass tube, and comprises the following steps:

s1, sequentially installing the systems on the upper side and the lower side of a conveying roller way of the glass tube, adjusting the angle of a rotating mirror in each optical assembly to enable a laser beam to form an emergence angle of 45 degrees with a horizontal plane, and adjusting the vertical distance between each optical assembly and the conveying roller way, the horizontal distance between each optical assembly and the image processing assembly and the vertical distance between each optical assembly and the image processing assembly to enable the laser beam emitted by each optical assembly to form strip-shaped light spots on the image processing assembly after being reflected by the glass tube, wherein the light spots are not overlapped;

s2, when the glass tube moves to an online detection area on the roller conveyor, initializing the system starting parameters;

s3, the optical components simultaneously emit laser beams, after the laser beams are reflected by the glass tube, the laser beams emitted by the first optical component form a first strip-shaped light spot on the first CCD image sensor, the laser beams emitted by the second optical component form a second strip-shaped light spot on the second CCD image sensor, the laser beams emitted by the third optical component form a third strip-shaped light spot on the first CCD image sensor, the laser beams emitted by the fourth optical component form a fourth strip-shaped light spot on the second CCD image sensor, and after the images of the light spots are collected by the image collector, the images of the light spots are analyzed by the signal processor;

s4, the width of the first strip-shaped light spot is t₁', the width of the second strip-shaped light spot is t₂', the width of the third strip-shaped light spot is t₁", the width of the fourth strip-shaped light spot is t₂", the wall thickness deviation between two symmetrical points of the same section of the glass tube

Wherein, delta₁And delta₂The thickness of the upper side wall and the thickness of the lower side wall of the glass tube are respectively, and n is the refractive index of the glass tube.

Preferably, the accuracy of the online laser measurement method is ± 0.01 mm.

By adopting the technical scheme, compared with the prior art, the invention has the following technical effects:

the system and the method can accurately measure the wall thickness deviation between two symmetrical points of the same section of the glass tube in the production process without stopping, and the measured glass tube is not damaged by adopting a non-contact measuring method, so that the quality and the production efficiency of products are improved.

Drawings

FIG. 1 is a schematic diagram of an on-line laser measurement system according to the present invention;

wherein the reference numerals include: a first laser light source 11; a first beam expanding lens 12; a first rotating mirror 13; a second laser light source 21; a second expander lens 22; a second rotating mirror 23; the third laser light source 31; a third expander lens 32; a third rotating mirror 33; a fourth laser light source 41; a fourth expander lens 42; a fourth rotating mirror 43; a first charge coupled device image sensor 51; a second charge coupled device image sensor 52;

FIG. 2 is a schematic view of the principle in embodiment 1 of the present invention;

FIG. 3 is a schematic view of embodiment 1 of the present invention in which the left side is higher than the right side;

fig. 4 is a schematic diagram of the embodiment 1 of the present invention when the right side is higher than the left side.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It should be noted that the embodiments and features of the embodiments may be combined with each other without conflict.

The invention is further described with reference to the following drawings and specific examples, which are not intended to be limiting.

Example 1

As shown in fig. 2, the incident angle of the laser beam emitted by the optical assembly is α, the refraction angle of the glass tube varies according to the composition difference of the glass tube, but the refraction angle of the same glass tube is a constant value β; setting the refractive index of the glass tube as n, the thickness of the glass tube as delta, and the horizontal distance between two parallel light beams reflected and refracted by the upper surface and the lower surface of the wall of the glass tube as t; for the convenience of calculation, let α equal to 45 °, then

As can be seen from equation (1), the thickness δ of the glass tube is proportional to the horizontal distance t between the two parallel light beams, so δ can be calculated by measuring t.

The above measurement method is calculated in the case that the glass tube to be measured is horizontally placed, however, the following problems often exist in the actual operation process: firstly, on a continuous production line, a glass tube conveying roller table is difficult to maintain absolute level; second, the glass tube inevitably causes vibration during movement, deviating from a horizontal position. Therefore, the measured glass tube thickness calculated by the ideal method has a certain deviation from the actual value, and the deviation is random and cannot be corrected by a formula, but can be compensated by the following analysis:

firstly, after a laser beam emitted by a laser light source is expanded by a beam expanding lens, the laser beam is projected onto a glass tube by a scanning light band line, so that the problems that the position of a reflected light point is easy to deviate, the intensity of the reflected light and the trend position of the reflected light are changed and the measurement result is easy to be influenced in the traditional laser photoelectric reflection method can be solved;

② as shown in figure 3, when the left side of the glass tube to be tested is higher than the right side,

90°-∠2+∠1＝90°-θ；θ＝∠2-∠1

because θ >0, β < β '< 90 °, i.e., the incident angle increases, so tan β < tan β';

δ＝t/2tanβ

δ is not changed, tan β is increased, t "> t, and the system cannot perceive the change, so the measured δ is larger than the actual value.

As shown in fig. 4, when the right side of the glass tube to be measured is higher than the left side,

90°-∠2+∠1＝90°+θ；θ＝∠1-∠2

because θ >0, β '< β <90 °, i.e., the incident angle decreases, so tan β' < tan β;

δ＝t/2tanβ

δ is not changed, tan β is decreased, t "< t, and the system cannot perceive the change, so the measured δ is smaller than the actual value.

Therefore, the application relates to a double-optical-path thickness measuring system which can effectively compensate the random deviation, and the specific implementation mode is as follows.

Example 2

As shown in fig. 1, the present embodiment provides an on-line laser measurement system for measuring wall thickness deviation between two symmetrical points of a glass tube with a cross section, comprising: the optical device comprises a first optical assembly, a second optical assembly, a third optical assembly, a fourth optical assembly and an image processing assembly;

the first optical assembly and the third optical assembly are arranged above a conveying roller way of the glass tube, the second optical assembly and the fourth optical assembly are arranged below the conveying roller way of the glass tube, the first optical assembly and the second optical assembly are arranged on a vertical surface, the first optical assembly and the third optical assembly are arranged on a horizontal surface, the second optical assembly and the fourth optical assembly are arranged on another horizontal surface, and the third optical assembly and the fourth optical assembly are arranged on another vertical surface;

and laser beams emitted by the first optical assembly, the second optical assembly, the third optical assembly or the fourth optical assembly are reflected by the glass tube to form a strip-shaped light spot on the image processing assembly.

As a preferred embodiment, the first optical assembly comprises: a first laser light source 11, a first expander lens 12, and a first rotating mirror 13;

the laser beam emitted by the first laser source 11 is expanded by the first expander lens 12, and then reflected by the first rotating mirror 13, so that the laser beam forms an exit angle of 45 degrees with the horizontal plane.

As a preferred embodiment, the second optical component comprises: a second laser light source 21, a second expander lens 22, and a second rotating mirror 23;

after being expanded by the second expander lens 22, the laser beam emitted by the second laser light source 21 is reflected by the second rotating mirror 23, so that the laser beam forms an exit angle of 45 degrees with the horizontal plane.

As a preferred embodiment, the third optical assembly comprises: a third laser light source 31, a third expander lens 32, and a third rotating mirror 33;

the laser beam emitted by the third laser light source 31 is expanded by the third expander lens 32, and then reflected by the third rotating mirror 33, so that the laser beam forms an exit angle of 45 degrees with the horizontal plane.

As a preferred embodiment, the fourth optical assembly includes: a fourth laser light source 41, a fourth expander lens 42, and a fourth rotating mirror 43;

the laser beam emitted by the fourth laser light source 41 is reflected by the fourth rotating mirror 43 after being expanded by the fourth beam expanding lens 42, so that the laser beam forms an exit angle of 45 degrees with the horizontal plane.

As a preferred embodiment, the image processing assembly comprises: a first charge coupled device image sensor 51, a second charge coupled device image sensor 52, an image collector, and a signal processor;

the first ccd image sensor 51 and the second ccd image sensor 52 are electrically connected to the image collector, respectively, and the image collector is electrically connected to the signal processor.

In a preferred embodiment, the laser beams emitted by the first optical assembly and the third optical assembly are reflected by the glass tube to form a strip-shaped light spot on the first ccd image sensor 51.

In a preferred embodiment, the laser beams emitted by the second optical assembly and the fourth optical assembly are reflected by the glass tube to form a strip-shaped light spot on the second ccd image sensor 52.

Example 3

This example provides an on-line laser measurement method using the system of example 2, where the method is used to measure the wall thickness deviation between two symmetrical points on the same cross section of a glass tube, and the method includes the steps of:

s1, sequentially installing the systems in the embodiment 2 on the upper side and the lower side of a conveying roller way of the glass tube, adjusting the angle of a rotating mirror in each optical assembly to enable a laser beam to form an emergence angle of 45 degrees with a horizontal plane, and adjusting the vertical distance between each optical assembly and the conveying roller way, the horizontal distance between each optical assembly and the image processing assembly and the vertical distance between each optical assembly and the image processing assembly to enable the laser beam emitted by each optical assembly to form strip-shaped light spots on the image processing assembly after being reflected by the glass tube, wherein the light spots are not overlapped;

s2, when the glass tube moves to an online detection area on the roller conveyor, initializing the system starting parameters;

s3, the optical components simultaneously emit laser beams, after being reflected by the glass tube, the laser beam emitted by the first optical component forms a first band-shaped light spot on the first ccd image sensor 51, the laser beam emitted by the second optical component forms a second band-shaped light spot on the second ccd image sensor 52, the laser beam emitted by the third optical component forms a third band-shaped light spot on the first ccd image sensor 51, the laser beam emitted by the fourth optical component forms a fourth band-shaped light spot on the second ccd image sensor 52, and after being collected by the image collector, images of the light spots are analyzed by the signal processor;

s4, the width of the first strip-shaped light spot is t₁', the width of the second strip-shaped light spot is t₂', the width of the third strip-shaped light spot is t₁", the width of the fourth strip-shaped light spot is t₂", the wall thickness deviation between two symmetrical points of the same section of the glass tube

Wherein, delta₁And delta₂The upper side wall thickness and the lower side wall thickness of the glass tube are respectivelyAnd n is the refractive index of the glass tube.

Preferably, the accuracy of the online laser measurement method is ± 0.01 mm.

In conclusion, the system and the method can accurately measure the wall thickness deviation between two symmetrical points of the same section of the glass tube in the production process without stopping, and the measured glass tube is not damaged by adopting a non-contact measuring method, so that the quality and the production efficiency of products are improved.

While the invention has been described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention.

Claims (10)

1. An on-line laser measurement system for measuring wall thickness deviation between two symmetrical points of a glass tube with a cross section, comprising: the optical device comprises a first optical assembly, a second optical assembly, a third optical assembly, a fourth optical assembly and an image processing assembly;

the first optical assembly and the third optical assembly are arranged above a conveying roller way of the glass tube, the second optical assembly and the fourth optical assembly are arranged below the conveying roller way of the glass tube, the first optical assembly and the second optical assembly are arranged on a vertical surface, the first optical assembly and the third optical assembly are arranged on a horizontal surface, the second optical assembly and the fourth optical assembly are arranged on another horizontal surface, and the third optical assembly and the fourth optical assembly are arranged on another vertical surface;

and laser beams emitted by the first optical assembly, the second optical assembly, the third optical assembly or the fourth optical assembly are reflected by the glass tube to form a strip-shaped light spot on the image processing assembly.

2. The system of claim 1, wherein the first optical assembly comprises: a first laser light source (11), a first beam expanding lens (12), and a first rotating mirror (13);

the laser beam emitted by the first laser source (11) is reflected by the first rotating mirror (13) after being expanded by the first beam expanding lens (12), so that the laser beam forms an exit angle of 45 degrees with the horizontal plane.

3. The system of claim 1, wherein the second optical assembly comprises: a second laser light source (21), a second expander lens (22), and a second rotating mirror (23);

after being expanded by the second beam expanding lens (22), the laser beam emitted by the second laser light source (21) is reflected by the second rotating mirror (23), so that the laser beam forms an exit angle of 45 degrees with the horizontal plane.

4. The system of claim 1, wherein the third optical assembly comprises: a third laser light source (31), a third expander lens (32), and a third rotating mirror (33);

the laser beam emitted by the third laser source (31) is reflected by the third rotating mirror (33) after being expanded by the third beam expanding lens (32), so that the laser beam forms an exit angle of 45 degrees with the horizontal plane.

5. The system of claim 1, wherein the fourth optical assembly comprises: a fourth laser light source (41), a fourth expander lens (42), and a fourth rotating mirror (43);

the laser beam emitted by the fourth laser light source (41) is reflected by the fourth rotating mirror (43) after being expanded by the fourth beam expanding lens (42), so that the laser beam forms an exit angle of 45 degrees with the horizontal plane.

6. The system of claim 1, wherein the image processing component comprises: a first charge coupled device image sensor (51), a second charge coupled device image sensor (52), an image collector and a signal processor;

the first CCD image sensor (51) and the second CCD image sensor (52) are respectively electrically connected with the image collector, and the image collector is electrically connected with the signal processor.

7. The system according to claim 6, wherein the laser beams emitted by the first optical assembly and the third optical assembly form a strip-shaped light spot on the first CCD image sensor (51) after being reflected by the glass tube.

8. The system of claim 6, wherein the laser beams emitted by the second optical assembly and the fourth optical assembly form a band-shaped spot on the second CCD image sensor (52) after being reflected by the glass tube.

9. An on-line laser measurement method using the system according to any one of claims 1 to 8, for measuring wall thickness deviation between two symmetrical points of a cross section of a glass tube, comprising the steps of:

s1, sequentially mounting the system according to any one of claims 1-8 on the upper side and the lower side of a roller way of the glass tube, adjusting the angle of a rotating mirror in each optical assembly to enable a laser beam to form an emergence angle of 45 degrees with the horizontal plane, and adjusting the vertical distance between each optical assembly and the roller way, the horizontal distance between each optical assembly and the image processing assembly, and the vertical distance between each optical assembly and the image processing assembly to enable the laser beam emitted by each optical assembly to form strip-shaped light spots on the image processing assembly after being reflected by the glass tube, wherein the light spots are not overlapped;

s2, when the glass tube moves to an online detection area on the roller conveyor, initializing the system starting parameters;

s3, the optical components simultaneously emit laser beams, after the laser beams are reflected by the glass tube, the laser beams emitted by the first optical component form a first strip-shaped light spot on the first CCD image sensor (51), the laser beams emitted by the second optical component form a second strip-shaped light spot on the second CCD image sensor (52), the laser beams emitted by the third optical component form a third strip-shaped light spot on the first CCD image sensor (51), the laser beams emitted by the fourth optical component form a fourth strip-shaped light spot on the second CCD image sensor (52), and after the images of the light spots are collected by the image collector, the images of the light spots are analyzed by the signal processor;

s4, the width of the first strip-shaped light spot is t₁', the width of the second strip-shaped light spot is t₂', the width of the third strip-shaped light spot is t₁", the width of the fourth strip-shaped light spot is t₂", the wall thickness deviation between two symmetrical points of the same section of the glass tube

Wherein, delta₁And delta₂The thickness of the upper side wall and the thickness of the lower side wall of the glass tube are respectively, and n is the refractive index of the glass tube.

10. The on-line laser measuring method according to claim 9, wherein the accuracy of the on-line laser measuring method is ± 0.01 mm.

Images