Laser line extraction and cross-section geometry measurement algorithm
The laser line extraction and cross-section geometry measurement algorithm processes the laser stripes on the surface of the workpiece, combines with applicable calibration to form the X-Z cross-section, and then calculates geometric quantities such as width and height, steps, gaps, surface differences or grooves according to the task. The calibrated contour output by the sensor can also be accessed, but the data interface and coordinate meaning need to be confirmed first.
Project Judgment Summary
Process tasks and input
The bright lines of the laser stripe in the image are not directly available as millimeter contours. Surface reflections, occlusions and multiple stripes can affect center extraction, and dimensional measurements also require reliable coordinates and business datums.
Input requirements: original laser fringe pattern, camera internal and external parameters, distortion and laser plane parameters, or calibration profile with unit/coordinate description; section datum, feature definition and allowable error are also required.
| Function | processing content | current base |
|---|---|---|
| Stripe center and effective segment extraction | Extract sub-pixel ridges and add branch correlation, noise/reflection exclusion and missing detection markers by business. | The foundation of the line center already exists; multi-branch correlation needs to be adapted |
| Pixel to section coordinates | Calculate the cross-section points based on the known camera and laser plane geometry; calibration acquisition, parameter solution and on-site verification need to be completed as independent tasks. | The intersection of known parameters has been completed; the real machine calibration needs to be completed. |
| Sectional Characteristic Calculation | Calculate gaps, surface differences, width and height, angles and cross-sectional areas based on specified surfaces, boundaries, straight lines or arcs, and do not fill invalid points into qualified values. | The basics of straight line/circle fitting are already available; task characteristics need to be developed |
Output content
| result | unit or form | Instructions for use |
|---|---|---|
| outline | X-Z coordinate/mm, valid point mask | Coordinate definition, calibration and time/piece number traceability |
| Dimensional and shape characteristics | mm, angle or cross-sectional area | Baselines, segmentation rules and invalid conditions are explained separately. |
| Abnormal results | Missing tests, reflective ambiguity, no valid reference | Image validity separate from product qualification determination |
Applicable conditions and boundaries
Applicable tasks: Visible geometric measurement of assembly gap differences, profiles/tongue and groove sections, strip width and height and cold welds/bevels.
A single section does not directly give the entire part volume or a complete three-dimensional surface; the surface weld profile does not demonstrate weld penetration, internal porosity, or strength. Specular, transparent and deep cavity occlusion require actual optical verification. The ring laser light cone cannot be applied to the single plane model.
Verification basis and delivery scope
There are limited public sample runs and positioning comparisons for line center extraction, and some of the tests use reference marking to limit the area; it cannot be claimed that the unknown scene has been fully recognized based on this. Triangular geometry currently verifies known parameter conditions, and actual machine plane calibration, full field line correlation and product dimensional accuracy have not yet been verified.
Image/contour input, active areas and datums, dimensional characteristics, results interfaces and recipe reporting are adapted to the task. If a commercial contour sensor is integrated, the division of labor between its own calibration and its own business algorithm should be clarified, and the sensor performance should not be rewritten as its own algorithm indicators.
Requirement confirmation information: Provide original fringe drawings or contour files with exceptions, coordinates/units, cross-sectional drawings, material surfaces, visual fields, beats and reference dimensions.
FAQ
Can the millimeter be measured after extracting bright lines from the picture?
No. The image centerline is still in pixel coordinates and requires suitable opto-mechanical geometry and calibration to form a physical section.
Can the welding be judged to be qualified if the weld surface is normal?
cannot. This algorithm is only responsible for the agreed visible geometry, and the internal quality and connection performance need to be tested accordingly.
Enterprise project promotion and acceptance
- scope confirmationClarify the objects, workstations, inputs, outputs, units, interfaces and abnormal conditions that must be covered.
- Sample verificationUse representative normal and abnormal samples to establish a baseline and record what works, what fails, and data gaps.
- Development joint debuggingComplete the algorithm, calibration, interface and equipment adaptation according to the approved scope, and retain the version, parameters and abnormal status.
- Item acceptanceUse independent samples and reference value retests to confirm errors, detection, tempo, stability and deliverables respectively.
Define the Development Scope with Samples and Device Requirements
Laser line extraction and cross-section geometry measurement algorithm
Please describe the task object, original picture or video, target indicators, device platform, interface and sample situation.
Phone: 13910119357xuzhiyang0928@gmail.com