CN116571875A

CN116571875A - Laser processing and detecting integrated equipment and method based on active projection technology

Info

Publication number: CN116571875A
Application number: CN202310854015.3A
Authority: CN
Inventors: 白锦轩; 徐爽; 钱林茂; 韩艳君
Original assignee: Southwest Jiaotong University
Current assignee: Southwest Jiaotong University
Priority date: 2023-07-13
Filing date: 2023-07-13
Publication date: 2023-08-11
Anticipated expiration: 2043-07-13
Also published as: CN116571875B

Abstract

The invention discloses laser processing and detecting integrated equipment and a detection method based on an active projection technology, wherein the equipment comprises a protection room, a laser processing device is arranged in the protection room, and a camera is arranged on the side wall of the protection room; the laser processing device comprises a base, a workbench is arranged above the base, and a laser generator and a vibrating mirror are arranged on the workbench; the laser generator is connected with the vibrating mirror through an optical path system; the inside at the guard house still is provided with the structure light projector, and the structure light projector sets up the upper end at the guard house lateral wall. By the device, the volume of the light path is reduced, and the space occupied by the laser processing device is saved. The camera and the structured light projector are arranged to detect the processed workpiece, and whether the error exists in the processing of the workpiece is obtained through the detection result, and the processing is adjusted and corrected according to the error information, so that the purpose of assisting the laser processing device in processing the workpiece is achieved, and the processing quality and the processing efficiency are ensured.

Description

Laser processing and detecting integrated equipment and method based on active projection technology

Technical Field

The invention belongs to the technical field of laser processing, and particularly relates to laser processing and detection integrated equipment and a detection method based on an active projection technology.

Background

Ultraviolet laser processing is realized through photochemical ablation, namely atoms or intermolecular bonding is broken by means of ultraviolet laser energy, so that the atoms or the intermolecular bonding is converted into small molecules, gasified and evaporated. The ultraviolet laser focusing light spot is very small, and the processing heat affected zone is very small, so that ultra-fine carving and special material processing can be performed. The ultraviolet laser processing adopts a cold light source, the wavelength is only 355nm, the diameter of a focusing light spot is small, the absorptivity of various materials to ultraviolet light is high, and the thermal influence is extremely small (negligible). This characteristic allows the ultraviolet laser processing to achieve a fine processing effect.

In the prior art, the ultraviolet laser processing equipment emits laser from a laser, then enters the vibrating mirror through an optical path system, and acts on the surface of a workpiece after being deflected and focused by the vibrating mirror, and because the laser generated by the laser cannot be transmitted through an optical fiber line, the optical path and the laser must be in the same plane, and the relative positions of the laser, the optical path and the vibrating mirror must not change when the focal length of the laser is adjusted, so that the whole optical path occupies a larger space, the laser cannot be used in places with smaller space, the high-power laser is heavier, and a lifting system for adjusting the focal length of the optical path drives the laser, the optical path and the vibrating mirror to move together at the same time, so that the load requirement on a lifting platform is higher.

When the laser is used for processing materials, the laser has the characteristics of being capable of processing complex textures, free from cutter damage introduction and the like, but the laser processing is easy to have processing defects such as taper, corrugation and the like in the practical application process, and the phenomena such as oxidization, layering, cracking and the like of a workpiece can be caused by the existence of a heat affected zone. Therefore, the invention provides the laser processing and detecting integrated equipment and the detection method based on the active projection technology, which can detect the surface defects of the material when the material is processed, and adjust and correct the laser processing process according to the detection information so as to achieve the aim of assisting the laser processing device to process the workpiece.

The three-dimensional reconstruction of structured light is a three-dimensional shape detection method based on optical principles and computer vision technology. The method utilizes a structured light projector to project a specific coded light pattern onto a target object, and acquires the three-dimensional geometric shape of the object surface by capturing light reflected or scattered by the object surface and analyzing deformation information thereof.

Three-dimensional reconstruction of target objects in the past often required the use of expensive laser scanners or complex photogrammetry systems to acquire their geometric information. However, with the development of computer vision and projection technology, three-dimensional reconstruction of structured light is a more efficient and economical method, and is widely applied to the fields of computer graphics, computer vision, virtual reality, industrial manufacturing and the like. The basic principle of three-dimensional reconstruction of structured light is to project a structured light pattern (usually stripes or a coded pattern) onto a target object, then capture the light reflected or scattered by the object surface with a camera or sensor, and by analyzing the deformation of the captured light pattern at the object surface, the depth or three-dimensional coordinates of the object surface can be deduced.

Disclosure of Invention

The invention aims to provide laser processing and detection integrated equipment and a detection method based on an active projection technology, which are used for solving the problems that in the prior art, the occupied space of an optical path is large, a lifting system which cannot be used in places with small space and can adjust the focal length of the optical path drives a laser, the optical path and a galvanometer to move together, the weight of a large-power laser is heavy and the load requirement on a lifting platform is high, and the forming error cannot be detected in time in the practical application process of laser processing, such as taper, ripple and other processing defects which are easy to occur in the processing process.

In order to solve the technical problems, the invention adopts the following technical scheme:

the laser processing and detecting integrated equipment based on the active projection technology comprises a protection room, wherein a laser processing device is arranged in the protection room;

the laser processing device comprises a base, a workbench is arranged above the base, and a laser generator and a vibrating mirror are arranged on the workbench; the laser generator is connected with the vibrating mirror through an optical path system; the workbench is also provided with a processing table, the processing table is arranged below the vibrating mirror, and the processing table is used for installing a workpiece;

a structured light projector is arranged in the protective room, and the structured light projector is arranged at the upper end of the side wall of the protective room; the structured light projector is used for projecting the coded stripes onto the surface of the workpiece, and a camera is further arranged on the side wall of the protective room and used for recording deformed stripe images which are modulated by the height of the imaged workpiece.

According to the technical scheme, the optical path system comprises an optical cylinder, a laser refraction cylinder and a telescopic cylinder; the laser refraction cylinder comprises a first refraction cylinder, a second refraction cylinder and a third refraction cylinder; one end of the first light cylinder is connected with the laser generator, and the other end of the first light cylinder is connected with the first refraction cylinder; one end of the second light cylinder is connected with the first refraction cylinder, and the other end of the second light cylinder is connected with the second refraction cylinder;

the second refraction cylinder is connected with a third refraction cylinder through a telescopic cylinder, and the third refraction cylinder is connected with the vibrating mirror.

According to the technical scheme, the telescopic cylinder comprises a first connecting section and a second connecting section; one end of the first connecting section is connected with the second refraction barrel, the second connecting section is connected with the third refraction barrel, and the first connecting section and the second connecting section are connected through a tubular organ cover.

According to the technical scheme, the workbench comprises a fixed seat and a supporting upright post; wherein, the support post is fixed to be set up on the fixing base, and the top of support post is provided with the crossbeam, and laser generator is fixed to be set up on the crossbeam.

According to the technical scheme, the beam is further provided with a driving assembly, and the driving assembly is used for driving the vibrating mirror to move up and down.

According to the technical scheme, the driving assembly comprises a slide rail seat, a driving device and a mounting table; the sliding rail seat is fixedly arranged on the cross beam, the driving device is arranged above the sliding rail seat, a screw rod is arranged in the sliding rail seat, and the driving device is used for driving the screw rod to rotate;

the mounting table is connected with the sliding rail seat in a sliding way, and penetrates through the sliding rail seat to be connected with the screw rod; the mounting table is driven to move up and down by the rotation of the lead screw; the vibrating mirror is fixedly arranged on the mounting table.

According to the technical scheme, the laser processing device further comprises a dust removing device; the dust removing device is used for removing dust in the laser processing process.

According to the technical scheme, the dust removing device comprises a dust collecting cover, a dust collecting pipeline and a dust collecting box; the dust hood is arranged on the side surface of the processing table, and an opening of the dust hood is arranged facing the processing table; the dust collection box is arranged on the side face of the base, and the dust collection pipeline is used for connecting the dust collection cover and the dust collection box.

According to the technical scheme, the workbench is further provided with a sliding platform, a first driving device and a second driving device; the processing platform is arranged on the sliding platform, and the sliding platform is in sliding connection with the workbench; the first driving device drives the sliding platform to move left and right on the workbench, and the second driving device drives the processing platform to move back and forth on the sliding platform;

the first driving device comprises a first motor and a first lead screw; the second driving device comprises a second motor and a second lead screw; the first screw rod is rotatably arranged in the workbench, the sliding platform is arranged on the first rotating screw rod, and the first motor drives the first screw rod to rotate; the second lead screw sets up in slide table's inside, and the processing platform slides and sets up on the second lead screw, and second motor drive second lead screw rotates.

The detection method of the laser processing and detection integrated equipment based on the active projection technology comprises the following steps of:

step S1, horizontally arranging a calibration plate on a workbench for binocular calibration;

s2, generating black and white stripes by utilizing a generating ePattern algorithm, writing the black and white stripes into a structured light projector to project the surface of a workpiece, and acquiring deformation stripes by a camera so as to acquire the wrapping phase of the workpiece;

step 3, performing phase unwrapping through a PhaseAnalyse algorithm, performing stereo matching on images acquired by two cameras (200) subjected to binocular calibration, calculating horizontal offset of corresponding pixels in left and right images, namely parallax, and obtaining three-dimensional information according to parallax information calculation and analysis; step 4, carrying out preprocessing operations such as denoising, filtering, registering and the like on the acquired three-dimensional data by utilizing an efficient and robust image processing and segmentation technology; then importing GOMSoftware to reconstruct point cloud, and performing processing operations such as point cloud splicing, segmentation, feature extraction, gridding and the like on the reconstructed point cloud to obtain more complete and accurate geometric feature of the surface texture so as to realize non-contact measurement;

and 5, comparing the ideal required point cloud diagram, utilizing Halcon to analyze the taper, waviness and bending characteristics of the laser processing surface of the material, feeding back the characteristic positions to a laser processing device, and optimizing the structural characteristics of the surface texture of the workpiece until the surface of the measuring plane and the surface of the target plane are flat, have no undulation or concave-convex, namely the tolerance range is +/-20 mu m, and the angle change is less than or equal to 1 DEG at the bending position.

Compared with the prior art, the invention has the following beneficial effects:

the device of the invention is used for arranging the laser generator and the vibrating mirror above the workbench and connecting the laser generator and the vibrating mirror through the light path system, thereby reducing the volume of the light path and saving the space occupied by the laser processing device.

And, through setting up camera and structured light projector in the inside of guard house, projection of stripe that will encode is to the work piece surface by the formation of image through structured light projector, the camera that rethread set up catches the deformation stripe, detects the work piece of accomplishing the processing, whether there is the error in the processing of work piece through the testing result, when the testing result shows that there is the error in work piece processing, gives laser control center with error information transfer, laser control center adjusts and corrects the course of working according to error information.

The purpose of assisting the laser processing device in processing the workpiece is achieved, and therefore the processing quality and the processing efficiency are guaranteed.

Drawings

FIG. 1 is a schematic side view of the overall structure of the present invention;

FIG. 2 is a schematic diagram of the overall front view of the present invention;

FIG. 3 is a schematic view of a laser processing apparatus according to the present invention;

FIG. 4 is a second schematic diagram of the laser processing apparatus according to the present invention;

FIG. 5 is a partially enlarged schematic illustration of the invention at A;

FIG. 6 is a schematic cross-sectional view of a drive assembly according to the present invention;

FIG. 7 is a schematic perspective view of a driving assembly according to the present invention;

FIG. 8 is a graph of the results of point cloud analysis of unsatisfactory workpiece processing in accordance with the present invention;

fig. 9 is a graph of the results of point cloud analysis of the workpiece processing compliance of the present invention.

The marks in the figure: 100-guard house, 200-camera, 300-laser processing device, 400-base, 500-workstation, 600-laser generator, 700-galvanometer, 800-processing platform, 900-structured light projector, 110-first light cylinder, 111-second light cylinder, 112-first refraction cylinder, 113-second refraction cylinder, 114-third refraction cylinder, 115-telescoping cylinder, 116-first connecting section, 117-second connecting section, 118-tubular organ cover, 119-fixing seat, 120-support column, 121-crossbeam, 122-driving component, 123-slide rail seat, 124-driving device, 125-mounting table, 126-lead screw, 127-dust removing device, 128-dust collecting cover, 129-dust collecting pipeline, 130-dust collecting box, 131-sliding platform.

Detailed Description

The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

Example 1

As shown in fig. 1, the integrated laser processing and detecting device and method based on active projection technology comprises a protection room 100, wherein a laser processing device 300 is arranged in the protection room 100, a camera 200 is arranged on the side wall of the protection room 100, and the camera 200 is used for recording deformation fringe images modulated by the height of an imaged workpiece;

as shown in fig. 2, the laser processing apparatus 300 includes a base 400, a table 500 provided above the base 400, and a laser generator 600 and a galvanometer 700 provided on the table 500; wherein, the laser generator 600 is connected with the vibrating mirror 700 through an optical path system; a processing table 800 is further arranged on the workbench 500, the processing table 800 is arranged below the vibrating mirror 700, and the processing table 800 is used for installing a workpiece;

a structured light projector 900 is arranged in the protective house 100, and the structured light projector 900 is arranged at the upper end of the side wall of the protective house 100; the structured light projector 900 is used for projecting encoded fringes onto a workpiece surface, and a camera 200 is further provided on a side wall of the guard house 100, and the camera 200 is used for recording a deformed fringe image highly modulated by an imaged workpiece.

By the device, the laser generator 600 and the galvanometer 700 are arranged above the workbench 500, and the laser generator 600 and the galvanometer 700 are connected through the optical path system, so that the volume of an optical path is reduced, and the space occupied by the laser processing device 300 is saved.

And, through setting up camera 200 and structured light projector 900 in the inside of guard house 100, project the stripe that encodes to the work piece surface that is imaged through structured light projector 900, the rethread camera 200 that sets up catches the deformation stripe, detect the work piece of accomplishing the processing, whether there is the error in the processing of work piece through the testing result, when the testing result shows that there is the error in work piece processing, transmit error information to laser control center, laser control center adjusts and corrects the course of working according to error information.

The purpose of assisting the laser processing device 300 in processing the workpiece is achieved, thereby ensuring the processing quality and the processing efficiency.

Example two

This embodiment is a further refinement of embodiment one.

As shown in fig. 4, the optical path system includes an optical barrel, a laser refraction barrel, and a telescopic barrel 115; wherein the light cylinders comprise a first light cylinder 110 and a second light cylinder 111, and the laser refraction cylinders comprise a first refraction cylinder 112, a second refraction cylinder 113 and a third refraction cylinder 114; one end of the first light cylinder 110 is connected to the laser generator 600, and the other end of the first light cylinder 110 is connected to the first refraction cylinder 112; one end of the second light cylinder 111 is connected to the first refraction cylinder 112, and the other end of the second light cylinder 111 is connected to the second refraction cylinder 113;

the second refraction cylinder 113 is connected to a third refraction cylinder 114 through a telescopic cylinder 115, and the third refraction cylinder 114 is connected to the galvanometer 700.

Further, the first light cylinder 110 and the second light cylinder 111 are hollow cylinder structures; the sealing process is required for both ends of the first optical barrel 110, and the sealing process is also required for both ends of the second optical barrel 111.

Further, a refractive lens is fixedly arranged (for example, adhered and fixed) in the laser refractive cylinder, and the laser is refracted by 90 degrees through the refractive lens arranged in the laser refractive cylinder.

As shown in fig. 5, telescoping cylinder 115 includes a first connection section 116 and a second connection section 117; wherein, one end of the first connecting section 116 is connected with the second refraction cylinder 113, the second connecting section 117 is connected with the third refraction cylinder 114, and the first connecting section 116 and the second connecting section 117 are connected through a tubular organ cover 118.

Further, as shown in fig. 5, one end of the tubular organ cover 118 is fixedly connected with the second connecting section 117, the other end of the tubular organ cover 118 is fixedly connected with the first connecting section 116, and the tubular organ cover 118 has a certain elasticity.

Because the second connecting section 117 is fixedly connected with the third refraction barrel 114, the third refraction barrel 114 is fixedly connected with the vibrating mirror 700, when the driving component 122 drives the vibrating mirror 700 to move downwards, the third refraction barrel 114 and the second connecting section 117 are driven to move downwards together, so that the tubular organ cover 118 is deformed, and the tubular organ cover 118 is elongated.

The height of the vibrating mirror 700 is changed through the driving component 122 and the telescopic cylinder 115, so that the laser focal length is adjusted, and the laser processing device 300 is more flexible to process; the relative positions of the laser generator 600, the optical path system and the vibrating mirror can be kept unchanged, and the processing effect is ensured; moreover, the device of the invention has lower load requirements on the lifting system.

Further, the tubular organ cover 118 employs existing means, such as: a silver-coated KK118 tubular organ cover is adopted.

Further, the galvanometer 700 employs existing devices such as: FL7210-3D-300 dynamic focusing galvanometer.

Further, the camera 200 employs existing devices, such as: MV-CH120-11UM camera of Haikang Wei.

The workbench 500 comprises a fixed seat 119 and a supporting upright 120; wherein, the support upright 120 is fixedly arranged on the fixed seat 119, a beam 121 is arranged above the support upright 120, and the laser generator 600 is fixedly arranged on the beam 121; the beam 121 is further provided with a driving component 122, and the driving component 122 is used for driving the galvanometer 700 to move up and down.

As shown in fig. 3, by fixedly arranging the laser generator 600 and the driving unit 122 on the beam 121, the occupation space of the laser processing apparatus 300 can be effectively reduced on the premise of meeting the workpiece processing requirements.

As shown in fig. 6 and 7, the drive assembly 122 includes a slide rail seat 123, a drive 124, and a mounting table 125; the sliding rail seat 123 is fixedly arranged on the cross beam 121, the driving device 124 is arranged above the sliding rail seat 123, the screw rod 126 is arranged in the sliding rail seat 123, and the driving device 124 is used for driving the screw rod 126 to rotate;

the mounting table 125 is in sliding connection with the slide rail seat 123, and the mounting table 125 passes through the slide rail seat 123 to be connected with the screw rod 126; the mounting table 125 is driven to move up and down by the rotation of the screw rod 126; the vibrating mirror 700 is fixedly disposed on the mount 125.

Further, the driving device 124 employs a motor.

Further, a rail is further provided in the slide rail seat 123, and the mounting table 125 is slidably connected to the rail.

Further, two rails are provided, and the two rails are respectively provided on both sides of the screw 126.

Further, the slide rail seat 123 includes a mounting seat and a cover plate; wherein, the mount pad is fixed to be set up on crossbeam 121, is provided with the clearance between apron and the mount pad, mount pad 125 pass clearance and slide rail seat 123 sliding connection.

The laser processing apparatus 300 further includes a dust removing device 127; the dust removing device 127 is used to remove dust during laser processing. The dust removing device 127 includes a dust hood 128, a dust collecting pipe 129, and a dust box 130; wherein, the dust hood 128 is arranged at the side surface of the processing table 800, and the opening of the dust hood 128 is arranged facing the processing table 800; the dust box 130 is disposed at a side of the base 400, and the dust collecting duct 129 is used to connect the dust hood 128 with the dust box 130.

Further, a negative pressure fan is provided inside the dust box 130, and dust generated on the processing table 800 is collected by the negative pressure fan.

The workbench is also provided with a sliding platform 131, a first driving device and a second driving device; the processing platform is arranged on the sliding platform 131, and the sliding platform 131 is in sliding connection with the workbench; the first driving device drives the sliding platform 131 to move left and right on the workbench, and the second driving device drives the processing platform to move back and forth on the sliding platform 131;

the first driving device comprises a first motor and a first lead screw; the second driving device comprises a second motor and a second lead screw; the first screw rod is rotatably arranged in the workbench, the sliding platform 131 is arranged on the first rotating screw rod, and the first motor drives the first screw rod to rotate; the second lead screw is arranged in the sliding platform 131, the processing platform is arranged on the second lead screw in a sliding mode, and the second motor drives the second lead screw to rotate.

The working principle of the invention is as follows: when in use, laser is refracted for multiple times by the cooperation of the laser generator 600 and the optical path system, then transmitted to the vibrating mirror 700, and then processed by the vibrating mirror 700.

When the height of the vibrating mirror 700 needs to be adjusted, the driving assembly 122 drives the vibrating mirror 700, the third refraction cylinder 114 and the second connection section 117 to move downwards together, so that the tubular organ cover 118 is deformed, and the tubular organ cover 118 is elongated, thereby completing the height adjustment of the vibrating mirror 700.

Example III

step S1, horizontally arranging a calibration plate on a workbench 500 for binocular calibration;

step S2, generating black and white stripes by utilizing a generating ePattern algorithm, writing the black and white stripes into a structured light projector 900 to project the surface of a workpiece, and acquiring deformed stripes by a camera 200 so as to acquire the wrapping phase of the workpiece;

step S3, performing phase unwrapping through a Phaseanalysis algorithm, performing stereo matching on images acquired by the two cameras (200) after binocular calibration, calculating horizontal offset of corresponding pixels in left and right images, namely parallax, and obtaining three-dimensional information according to parallax information calculation and analysis;

step S4, preprocessing operations such as denoising, filtering, registering and the like are carried out on the acquired three-dimensional data by utilizing an efficient and robust image processing and segmentation technology; then importing GOMSoftware to reconstruct point cloud, and performing processing operations such as point cloud splicing, segmentation, feature extraction, gridding and the like on the reconstructed point cloud to obtain more complete and accurate geometric feature of the surface texture so as to realize non-contact measurement;

and S5, comparing the ideal required point cloud diagram, utilizing Halcon to analyze the taper, waviness and bending characteristics of the laser processing surface of the material, feeding back the characteristic positions to a laser processing device, and optimizing the structural characteristics of the surface texture of the workpiece until the surface of the measuring plane and the surface of the target plane are flat, have no undulation or concave-convex, namely the tolerance range is +/-20 mu m, and the angle change is less than or equal to 1 DEG at the bending position.

Halcon uses its image processing and machine vision algorithms to effect the identification of surface defects of a workpiece. Features of surface defects are extracted from the image using a Halcon feature extraction algorithm. These features may include texture, shape, edges, etc., with corresponding feature extraction methods being selected according to different defect types.

And matching the phase values in the left image and the right image, and finding out the matching point with the minimum phase difference of each pixel point in the left image in the right image. For each matching point, the horizontal offset, i.e., parallax, of the corresponding pixel in the left and right images is calculated. And establishing a geometric relation between depth and parallax by utilizing a triangle ranging principle, thereby obtaining the depth information of each point on the surface of the target object.

Compared with pure binocular stereo matching, the advantages of binocular stereo matching based on structured light:

robustness is stronger: the structured light projects the encoded information onto the surface of the target object, and by adding the characteristic information, the matching robustness can be improved. Compared with pure binocular matching, the structured light provides additional constraint conditions, and reduces the influence of factors such as illumination change, texture deletion and the like.

Matching points are dense: the structured light forms coding information on the surface of the target object, so that more matching points can be obtained, and the depth estimation density is improved. Compared with pure binocular matching, the structured light provides more characteristic points, and can obtain higher matching precision and consistency.

The illumination has little influence: the coded information of the structured light projection can effectively reduce the influence of illumination change on depth estimation. By coding the structured light, the matching process is more stable, and depth estimation errors caused by illumination condition changes are reduced.

Further, the specific implementation of the generatepater algorithm is as follows:

function[Is,Is_img]=GeneratePattern(A,B,T,N,W,H)Is=cell(N,1);

Is_img=cell(N,1);

xs=1:W;

f_2pi=1./double(T)*2.*pi;fork=0:N-1Is{k+1}=A+B*cos(f_2pi*xs+2*k/N*pi);Is_img{k+1}=repmat(Is{k+1}/255.,H,1);

end

the generatePattern function first creates an array of empty cells, IS, and IS_img, of size N for storing the generated fringe pattern and image results. A row vector xs from 1 to W is created again for representing the abscissa of the pattern. A constant f_2pi is then calculated for subsequent calculation of the phase change amount. Next, a fringe pattern in each phase shift step is generated using a loop from 0 to N-1. The fringe pattern is generated using a cosine function, where f_2pi represents the amount of phase change. The generated fringe pattern Is stored in an Is array while being converted into an image format, and stored in an is_img array.

Function input parameters:

reference brightness of stripe (value range: 0-255)

B amplitude of stripe (value range: 0-255)

T period of stripe (unit: pixel)

N phase step number (number of stripes)

Width of pattern (unit: pixel)

H height of pattern (unit: pixel)

The amplitude, phase, period and number of stripes can be customized as desired by the generatepattterm algorithm. This enables flexible generation of fringe patterns of different shapes, frequencies and contrast to meet structured light imaging requirements. By adjusting the parameters, the degree and shape of the phase shift of each stripe can be precisely controlled. High-quality fringe patterns can be obtained, and the cosine function is used for generating the fringe patterns, so that the generator-pattern algorithm has higher signal quality and lower noise level when generating the fringes, and is beneficial to improving the precision and stability of structured light imaging. Easy realization: the code is written using MATLAB and uses simple and intuitive syntax and functions. This makes it simple and efficient to implement the stripe generation algorithm without requiring complex programming skills.

Example IV

The PhaseAnalyse algorithm is embodied as:

#include<opencv2/opencv.hpp>

#include<stdint.h>

#include<string>

#include<fstream>

Using namespace cv;

using namespace std;

1. # include < opencv2/opencv.hpp >: the header file used to introduce the OpenCV library includes functions and classes for image processing, computer vision, and machine learning.

2. # include < stdint.h >: for introducing an stdint.h header file defining integer types of fixed size, such as uint8_t, int16_t, etc.

3. # include < string >: for introducing a string header file that provides functions and classes for manipulating strings.

4. # include < fstream >: for introducing an fstream header file that provides functions and classes for reading and writing files.

#define F32 float

#define PIXEL uint8_t

#define PI 3.1415926535897932384626433832795

#define PI2 (PI*2)

static int m_dFreq[5]={1,3,9,27,85};

static int m_nHeight;

static int m_nWidth;

1. # define F32 float: a macro constant F32 is defined, representing the float type. By definition, the use of F32 may replace the use of float types.

2. # define PIXEL uint8_t: a macro constant PIXEL is defined, representing the uint8_t type. By definition, the use of PIXEL may replace the use of the uin8_t type.

3. # define PI 3.1415926535897932384626433832795: a macro constant PI is defined, representing the value of the circumference ratio PI. In the code, PI may be used instead of the specific numerical value 3.1415926535897932384626433832795.

4. Defined PI2 (PI x 2): a macro constant PI2 is defined, representing twice the circumference ratio PI. In the code, PI2 may be used instead of the specific value PI x 2.

5. static int m_dfreq [5] = {1,3,9,27,85}: a static integer array m_dfeq is defined, containing 5 elements. This array is initialized to {1,3,9,27,85}.

6. static int m_nHeight, and static int m_nWidth: two static integer variables, m_nhight and m_nwith, are defined, but are not given initial values. This means that their initial value will be 0 (initialized to 0 in the static memory area).

The specific implementation of the Phase Unwrap (Phase unwrrap) function is as follows:

voidPhaseUnWrap(Mat&phaseHetero,Mat&phaseWrap,Mat&phaseUnwrap,float frqHetero,float frqWrap){

F32*ptr0=(F32*)phaseHetero.data;

F32*ptr1=(F32*)phaseWrap.data;

F32*ptr=(F32*)phaseUnwrap.data;

float R=frqWrap/frqHetero;

for(inty=0;y<m_nHeight;y++){

floatphaWrapPrev=ptr1[0];

int NWrap=0;

for (int x=0;x<m_nWidth;x++){

int xy=y*m_nWidth+x;

F32&phaUnwrap=ptr[xy];

F32 phaHeter=ptr0[xy];

F32 phaWrap=ptr1[xy];

NWrap=(int)((phaHeter*R-phaWrap)/PI2+0.5);

phaUnwrap=NWrap*PI2+phaWrap;

}}}

the method comprises the steps of unpacking an input phase image through the algorithm, repairing the discontinuity of the phase image, and generating a continuous phase image. The input parameters of the function include three matrix-type parameters: phaseHetero, phaseWrap and phaseUnwrap. The clutter phase, the wrap phase and the unwrap phase are represented respectively. These phase images are typically stored in a floating point number (F32) type. The function first converts the data pointer of the phase image into a pointer of the F32 type, i.e. ptr0 points to the data of phaseheter, ptr1 points to the data of phaseWrap, ptr points to the data of phaseUnwrap. Next, the function calculates the R value from the given frequency parameters (frqheter and frqWrap), r=frqwrap/frqheter. This R value is used to map the wrapping phase to the clutter phase. r=frqwrap/frqHetero, a scaling factor can be obtained. The wrapped phase is multiplied by the proportionality coefficient, so that the wrapped phase can be mapped to the same frequency range as the clutter phase, and the wrapped phase has the same change rule. The function then traverses the entire image using a double loop, from the top left corner to the bottom right corner. At each pixel location, the function calculates the value of the unwrapped phase. First, the values of the clutter phase, the wrap phase and the unwrap phase of the current position are obtained. Next, the function calculates the wrap number (NWrap) of the phase from the phase difference and the R value. Then, the value of the unwrap phase is calculated from the wrapped number and the wrapped phase value. The unwrap phase is obtained by multiplying the wrapping number by 2pi and adding the wrapping phase. Finally, the function returns the unpacked phase image and stores the phase image in the phaseUnwrap matrix.

The PhaseAnalyse algorithm is simple and efficient, has simple code realization, and is easy to understand and use. It is based on simple mathematical operation, without complex algorithm and iterative process, so the execution speed is faster.

Multiple frequency unpacking: the algorithm realizes a multi-frequency phase unwrapping algorithm, uses different phase shift patterns, and can more accurately recover phase information. The multi-frequency unpacking method can improve the reliability and accuracy of unpacking.

The algorithm may be modified and adapted as desired. Parameters such as frequency, amplitude and the like of the phase shift pattern can be customized to adapt to different application scenes and experimental requirements.

Understanding of the formula:

1. first, the difference phaHeter R-phaWrap is calculated. This difference represents the amount of shift of the wrapping phase relative to the clutter phase.

2. The difference is divided by 2pi (i.e., PI 2) to convert the offset into units of parcel number. The result thus obtained represents the wrap-number offset of the wrap phase relative to the clutter phase.

3. The addition of 0.5 is to convert the floating point number result to an integer for rounding.

The phase unwrapping operation is realized through the phase unwrapping code, and continuous phase images are generated through repairing the discontinuity of the phase images.

void ImgShowAbsPhase(Mat mat,float offset, string title) {

Mat show = mat / offset;

imshow(title, show);

waitKey(0);}

1. A new Mat object show is created as the displayed image.

2. The input phase image mat is divided by the offset to obtain an adjusted image. The scaling factor of the phase image is used to adjust the contrast of the display. Dividing the phase image by offset can map the phase values to the appropriate display range.

3. And displaying the adjusted phase image show in a window by using an imshow function of OpenCV, wherein the title of the window is title.

The waitKey (0) function is invoked, waiting for the user to press any key on the keyboard to keep the window displayed.

The function is to scale and display the phase image so that the user can observe the characteristics of the phase distribution. This function is typically used to display the final phase result after processing steps such as phase unwrapping.

void DecodeMultiPhase5(Mat* imgShift, Mat&imgAbsPhase) {

F32* dPtr = (F32*)imgAbsPhase.data;

Mat imgPhase[5];

for (int k = 0; k<5; k++) imgPhase[k] = Mat::zeros(m_nHeight, m_nWidth, CV_32FC1);

for (int n = 0; n<4; n++) {

PIXEL* I0 = (PIXEL*)imgShift[4 * n + 0].data;

PIXEL* I1 = (PIXEL*)imgShift[4 * n + 1].data;

PIXEL* I2 = (PIXEL*)imgShift[4 * n + 2].data;

PIXEL* I3 = (PIXEL*)imgShift[4 * n + 3].data;

F32* pha = (F32*)imgPhase[n].data;

for (int k = 0; k<m_nWidth * m_nHeight; k++) {

pha[k] =(float)atan2f((double)(I1[k] - I3[k]), (double)(I0[k] - I2[k]));

if (pha[k]<0)

pha[k] +=PI2;

}}

PIXEL* I[8];

for (int k = 0; k<8; k++)

I[k] = (PIXEL*)imgShift[16 + k].data;

F32* pha = (F32*)imgPhase[4].data;

float PI2_8 = PI2 / 8;

for (int k = 0; k<m_nWidth * m_nHeight; k++) {

double ssin = 0.0, scos = 0.0;

for (int i = 0; i<8; i++) {

ssin += I[i][k]* sin(PI2_8 * i);

scos += I[i][k]* cos(PI2_8 * i);}

pha[k] = (float)atan2f(ssin, scos);

if (pha[k]<0)

pha[k] +=PI2;

}

ImgShowAbsPhase(imgPhase[0], PI2, "imgPhase_0");

ImgShowAbsPhase(imgPhase[1], PI2,"imgPhase_1");

ImgShowAbsPhase(imgPhase[2], PI2,"imgPhase_2");

ImgShowAbsPhase(imgPhase[3], PI2,"imgPhase_3");

ImgShowAbsPhase(imgPhase[4],PI2, "imgPhase_4");

Mat imgAbsPhase1 = Mat::zeros(m_nHeight, m_nWidth, CV_32FC1);

Mat imgAbsPhase2 = Mat::zeros(m_nHeight, m_nWidth, CV_32FC1);

Mat imgAbsPhase3 = Mat::zeros(m_nHeight, m_nWidth, CV_32FC1);

Mat M1 = Mat::zeros(m_nHeight, m_nWidth, CV_32FC1);

Mat M2 = Mat::zeros(m_nHeight, m_nWidth, CV_32FC1);

Mat M3 = Mat::zeros(m_nHeight, m_nWidth, CV_32FC1);

PhaseUnWrap(imgPhase[0], imgPhase[1], imgAbsPhase1, m_dFreq[0], m_dFreq[1]);

PhaseUnWrap(imgAbsPhase1, imgPhase[2],imgAbsPhase2, m_dFreq[1], m_dFreq[2]);

PhaseUnWrap(imgAbsPhase2, imgPhase[3],imgAbsPhase3, m_dFreq[2], m_dFreq[3]);

PhaseUnWrap(imgAbsPhase3, imgPhase[4], imgAbsPhase, m_dFreq[3], m_dFreq[4]);

ImgShowAbsPhase(imgAbsPhase1, 3 * PI2, "imgAbsPhase1");

ImgShowAbsPhase(imgAbsPhase2, 9 * PI2, "imgAbsPhase2");

ImgShowAbsPhase(imgAbsPhase3, 27 * PI2,"imgAbsPhase3");

ImgShowAbsPhase(imgAbsPhase, 81 * PI2, "imgAbsPhase");

imwrite("phase1.bmp", imgPhase[0]);

imwrite("phase2.bmp", imgPhase[1]);

imwrite("phase3.bmp", imgPhase[2]);

imwrite("phase4.bmp", imgPhase[3]);

imwrite("phase5.bmp", imgPhase[4]);

imwrite("unphase.bmp", imgAbsPhase);

return;}

The function accepts as input a picture array imgShift and a reference imgAbsPhase for the Mat object. An array imgPhase of Mat objects of size 5 is used for initialization. Each imgPhase element is initialized to an all-zero matrix having the same size as imgmabsphase. Next is a loop, with a loop variable n, traversing from 0 to 3. Within the loop, for each value of n, the function obtains four images I0, I1, I2, and I3 from the imgShift array. These images correspond to different phase shift steps. Then, the function traverses m_n width_m_n height pixels, and for each pixel, the phase value pha is calculated using an atan2f function. The calculation of the phase values is based on the differences between the pixel values in the images I0, I1, I2 and I3. If the phase value pha is less than 0, it is increased by PI2 to ensure that the phase value is between 0 and 2 PI.

Next, the function processes the last set of eight-step phase shifted images. These images are stored in a pointer array named I. Then, the function traverses m_n width_m_n height pixels, and for each pixel, the cumulative values of ssin and scos are calculated using sine and cosine functions. These accumulated values are used to calculate the phase value pha. Similar to the previous step, if the phase value pha is less than 0, it is increased by PI2. Finally, the function call imgshow abs phase function displays each element in the imgPhase array and saves it as an image file. Then, the PhaseUnWrap function is called to perform phase expansion on the imgPhase array, and imgAbsPhase is obtained. Finally, the function saves imgAbsPhase as an image file and returns.

Example five

As shown in fig. 8, the point cloud image shows a corresponding defect area of workpiece processing, and is represented as an abnormality or absence of point cloud data. The device then determines the location, shape and size of the defect, as well as the dimensional characteristics of the intact zone, based on the results of the point cloud analysis. Based on the information, the device aims at the problem that the size is not in accordance with the requirement, adjusts laser power, scanning speed, spot diameter and the like, and optimizes the processing process. After parameter adjustment, the detection result is shown in fig. 9, the size of the pattern of the processed workpiece meets the requirement, the length, width and thickness of the reserved square reach the expected 10mm×10mm×1mm, and the point cloud presents the shape and size consistent with the design without obvious abnormality or deletion.

It is noted that relational terms such as first and second, and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Moreover, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.

Finally, it should be noted that: the foregoing description is only a preferred embodiment of the present invention, and the present invention is not limited thereto, but it is to be understood that modifications and equivalents of some of the technical features described in the foregoing embodiments may be made by those skilled in the art, although the present invention has been described in detail with reference to the foregoing embodiments. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. Laser processing detects integration equipment based on initiative projection technique, its characterized in that: comprises a protection room (100), wherein a laser processing device (300) is arranged in the protection room (100);

the laser processing device (300) comprises a base (400), a workbench (500) is arranged above the base (400), and a laser generator (600) and a galvanometer (700) are arranged on the workbench (500); wherein, the laser generator (600) is connected with the vibrating mirror (700) through an optical path system; a processing table (800) is further arranged on the workbench (500), the processing table (800) is arranged below the vibrating mirror (700), and the processing table (800) is used for installing a workpiece;

a structured light projector (900) is arranged in the protective house (100), and the structured light projector (900) is arranged at the upper end of the side wall of the protective house (100); the structured light projector (900) is used for projecting coded stripes onto the surface of a workpiece, the side wall of the guard house (100) is further provided with a camera (200), and the camera (200) is used for recording deformed stripe images which are modulated by the height of the imaged workpiece.

2. The integrated laser machining and inspection device based on active projection technology according to claim 1, characterized in that: the optical path system comprises an optical cylinder, a laser refraction cylinder and a telescopic cylinder (115); wherein the light cylinders comprise a first light cylinder (110) and a second light cylinder (111), and the laser refraction cylinder comprises a first refraction cylinder (112), a second refraction cylinder (113) and a third refraction cylinder (114); one end of the first light cylinder (110) is connected with the laser generator (600), and the other end of the first light cylinder (110) is connected with the first refraction cylinder (112); one end of the second light cylinder (111) is connected with the first refraction cylinder (112), and the other end of the second light cylinder (111) is connected with the second refraction cylinder (113);

the second refraction cylinder (113) is connected with a third refraction cylinder (114) through a telescopic cylinder (115), and the third refraction cylinder (114) is connected with the vibrating mirror (700).

3. The integrated laser machining and inspection device based on active projection technology according to claim 2, characterized in that: the telescopic cylinder (115) comprises a first connecting section (116) and a second connecting section (117); one end of the first connecting section (116) is connected with the second refraction cylinder (113), the second connecting section (117) is connected with the third refraction cylinder (114), and the first connecting section (116) and the second connecting section (117) are connected through a tubular organ cover (118).

4. The integrated laser machining and inspection device based on active projection technology according to claim 1, characterized in that: the workbench (500) comprises a fixed seat (119) and a supporting upright post (120); wherein, support post (120) is fixed to be set up on fixing base (119), and the top of support post (120) is provided with crossbeam (121), and laser generator (600) is fixed to be set up on crossbeam (121).

5. The integrated laser machining and inspection device based on active projection technology according to claim 4, wherein: the beam (121) is also provided with a driving component (122), and the driving component (122) is used for driving the vibrating mirror (700) to move up and down.

6. The integrated laser machining and inspection device based on active projection technology according to claim 5, wherein: the driving assembly (122) comprises a slide rail seat (123), a driving device (124) and a mounting table (125); the sliding rail seat (123) is fixedly arranged on the cross beam (121), the driving device (124) is arranged above the sliding rail seat (123), a screw rod (126) is arranged in the sliding rail seat (123), and the driving device (124) is used for driving the screw rod (126) to rotate;

the mounting table (125) is in sliding connection with the slide rail seat (123), and the mounting table (125) penetrates through the slide rail seat (123) to be connected with the screw rod (126); the mounting table (125) is driven to move up and down by the rotation of the lead screw (126); the vibrating mirror (700) is fixedly arranged on the mounting table (125).

7. The integrated laser machining and inspection device based on active projection technology according to claim 1, characterized in that: the laser processing device (300) also comprises a dust removing device (127); the dust removing device (127) is used for removing dust in the laser processing process.

8. The integrated laser machining and inspection device based on active projection technology according to claim 7, wherein: the dust removing device (127) comprises a dust collecting cover (128), a dust collecting pipeline (129) and a dust collecting box (130); wherein the dust hood (128) is arranged on the side surface of the processing table (800), and an opening of the dust hood (128) is arranged facing the processing table (800); the dust box (130) is arranged on the side surface of the base (400), and the dust collecting pipeline (129) is used for connecting the dust collecting cover (128) and the dust box (130).

9. The integrated laser machining and inspection device based on active projection technology according to claim 1, characterized in that: the workbench (500) is also provided with a sliding platform (131), a first driving device and a second driving device; wherein, the processing table (800) is arranged on the sliding platform (131), and the sliding platform (131) is in sliding connection with the workbench (500); the first driving device drives the sliding platform (131) to move left and right on the workbench (500), and the second driving device drives the processing platform (800) to move back and forth on the sliding platform (131);

the first driving device comprises a first motor and a first lead screw; the second driving device comprises a second motor and a second lead screw; the first screw rod is rotatably arranged in the workbench (500), the sliding platform (131) is arranged on the first rotating screw rod, and the first motor drives the first screw rod to rotate; the second lead screw is arranged in the sliding platform (131), the processing table (800) is arranged on the second lead screw in a sliding mode, and the second motor drives the second lead screw to rotate.

10. The detection method of the laser processing and detection integrated equipment based on the active projection technology is characterized by comprising the following steps of: detection using the laser processing detection integrated device based on the active projection technique according to any one of claims 1 to 9, the detection method comprising the steps of:

step S1, horizontally arranging a calibration plate on a workbench (500) for binocular calibration;

s2, generating black and white stripes by utilizing a generating ePattern algorithm, writing the black and white stripes into a structured light projector (900) to project the surface of a workpiece, and acquiring deformed stripes by a camera (200), so as to acquire the wrapping phase of the workpiece;

step S3, performing phase unwrapping through a Phaseanalysis algorithm, performing three-dimensional matching on images acquired by the two cameras (200) after binocular calibration, namely matching corresponding pixel points, calculating parallax, and obtaining three-dimensional information according to parallax information calculation and analysis;

step S4, carrying out preprocessing operations of denoising, filtering and registering on the acquired three-dimensional data by utilizing an efficient and robust image processing and segmentation technology; then importing GOMSoftware to reconstruct point cloud, and performing point cloud splicing, segmentation, feature extraction and gridding treatment on the reconstructed point cloud to obtain more complete and accurate geometric feature of the surface texture so as to realize non-contact measurement;