Laser Cutting Contour Calibration Using Optical Deviation Mapping

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Solution Overview

Problem

Laser cutting machines face challenges in achieving both high precision and productivity due to contour deviations caused by inertia, resilience, and vibrations of machine components, which are not accurately measured by existing encoder systems, leading to reduced quality and increased production time.

Innovation Solution

A method involving a computer-implemented process that applies a reference texture, such as an engraving, to the workpiece, captures images with an optical device, and calculates displacement vectors to determine contour deviations, allowing for precise calibration and compensation of control instructions to correct these deviations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the cutting speed is increased to improve productivity, then the productivity increases, but the contour precision deteriorates due to overshooting from inertia and resilience

Engineering Contradiction:
Improvecutting speedVSAvoidcontour precision
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The patent applies preliminary action by pre-calculating and storing compensation values for contour deviations at different positions and speeds before actual cutting. The system determines the actual cutting contour by comparing target contour with pre-measured compensation data, allowing high-speed cutting while maintaining precision through pre-computed corrections.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent implements feedback by using optical measurement systems to detect actual cutting contours and comparing them with target contours. The system continuously monitors position deviations and uses encoder feedback to determine actual positions, creating a closed-loop control that corrects for inertia and resilience effects during cutting.

Inventive Principle:
Principle #23Feedback

2Manufacturing precision

If blanket restrictions are applied to machine dynamics to ensure contour accuracy, then the manufacturing precision improves, but the productivity decreases

Engineering Contradiction:
Improvecontour accuracyVSAvoidcutting speed
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The patent applies local quality by determining contour deviations specifically at corner positions and high-dynamic areas where precision problems occur, rather than applying blanket restrictions to the entire cutting path. The system measures and compensates for deviations locally at critical positions, allowing high-speed cutting in low-risk areas while maintaining precision at corners.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent changes parameters by storing multiple compensation values for different positions, speeds, and acceleration levels. The system selects appropriate compensation parameters based on actual cutting conditions, allowing dynamic adjustment of cutting parameters to maintain precision without blanket speed restrictions.

Inventive Principle:
Principle #35Parameter changes

3Manufacturing precision

If optical measurement systems are used to measure the actual cutting contour, then the manufacturing precision improves, but the device complexity increases

Engineering Contradiction:
Improvecontour measurement accuracyVSAvoidmeasurement system complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent applies copying by creating a digital model of the actual cutting contour through optical measurement and comparing it with the target contour model. The system uses camera-based optical systems to capture images of the workpiece and reconstruct the actual cutting path, providing a simplified digital copy for analysis and compensation.

Inventive Principle:
Principle #26Copying

4Device complexity

If internal encoder measurement systems are used to measure position, then the device complexity is reduced, but the measurement precision deteriorates because they cannot account for inertia and resilience

Engineering Contradiction:
Improvemeasurement system simplicityVSAvoidposition measurement accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent uses an intermediary approach by combining simple encoder measurements with optical measurement systems. The encoders provide basic position feedback while optical systems serve as intermediaries to measure actual cutting contours and detect deviations caused by inertia and resilience. The combined data provides accurate position and contour information without the complexity of purely optical systems.

Inventive Principle:
Principle #24Intermediary (Mediator)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach enables precise calibration of laser cutting machines without waste, improving quality and productivity by reducing contour errors and optimizing control values for machine components, thus enhancing the accuracy of cuts.

Implementation Method 1

spatially resolved detection of a surface area of the heated workpiece by the optical detector

Methodology Applied
Scientific EffectOptical detection: Reflection

Data Source

PatentEP4419286B1Determination of contour deviations for controlling a laser cutting machine
Publication Date: 2025.07.09 BYSTRONIC LASER AG
  • EP4419286B1 patent drawingFigure 1
  • EP4419286B1 patent drawingFigure 2
  • EP4419286B1 patent drawingFigure 3

AI summary

In one aspect, the present invention relates to the calculation of contour deviations (ka) for controlling a laser cutting machine (L) with control instructions (sa). The contour deviations (ka) are calculated from a displacement vector (vv), which is determined from an image comparison between an image captured by a camera (K) and a virtual reconstruction image (v). The virtual reconstruction image (v) is determined on the basis of a reference texture (RT) applied to the workpiece (W) and control values (sw).