Laser Piercing Depth Feedback Control for Faster Hole Quality

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

The efficiency of the piercing process in laser cutting is hindered by varying manufacturing tolerances in workpieces, leading to inconsistent process durations and inefficiencies, as existing methods lack real-time control over process parameters during the piercing operation.

Innovation Solution

A method and system that utilize an optical measuring device to continuously measure the piercing depth and adjust process parameters in real-time, allowing for inline control of the piercing process, optimizing the piercing hole quality and stability by adjusting parameters such as laser power, focus position, and process gas composition based on current piercing depth and rate of change.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the piercing process is performed without real-time measurement and control, then the process is simpler to operate, but the process duration increases and efficiency decreases due to varying manufacturing tolerances

Engineering Contradiction:
Improvepiercing process efficiencyVSAvoidprocess control complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent implements real-time feedback control by measuring the actual piercing depth during the process and using this information to dynamically adjust process parameters. The control device receives measurement data from the measuring device and automatically modifies at least one process parameter to optimize the piercing operation, thereby improving efficiency while maintaining manageable complexity through automated closed-loop control.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent applies dynamics by making the process parameters adjustable during the piercing process based on real-time measurements. Instead of using fixed parameters, the system dynamically adapts the laser power, pulse duration, or other process parameters according to the actual piercing depth and workpiece characteristics, enabling optimal performance across varying manufacturing tolerances.

Inventive Principle:
Principle #15Dynamics

2Productivity

If the piercing process duration is reduced to improve efficiency, then productivity increases, but the quality of the piercing hole may deteriorate due to insufficient control

Engineering Contradiction:
Improvepiercing process speedVSAvoidpiercing hole quality
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The real-time measurement and feedback control system monitors the piercing depth and adjusts process parameters dynamically to maintain optimal piercing conditions. This ensures that even when the process is accelerated, the quality criteria for the piercing hole (such as diameter, roundness, and surface quality) are consistently met through automated parameter optimization.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent changes process parameters in real-time based on measured piercing depth and workpiece properties. By dynamically adjusting parameters such as laser power, pulse duration, and focus position, the system maintains high piercing quality while enabling faster processing speeds, resolving the contradiction between productivity and manufacturing precision.

Inventive Principle:
Principle #35Parameter changes

3Manufacturing precision

If process parameters are adjusted in real-time based on measured piercing depth, then the piercing hole quality is optimized, but the device complexity increases

Engineering Contradiction:
Improvepiercing hole qualityVSAvoidmeasurement and control system complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent implements feedback control where a measuring device monitors the piercing depth and a control device automatically adjusts process parameters based on the measured values. This automated closed-loop system optimizes piercing hole quality while managing device complexity through integration of measurement and control functions within the existing laser processing system.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system performs self-adjustment by automatically modifying its own process parameters based on real-time measurements of the piercing process. The control device uses the measurement data to autonomously optimize the piercing parameters without requiring external intervention, thereby improving quality while keeping the operational complexity manageable through self-regulation.

Inventive Principle:
Principle #25Self-service

4Reliability

If a first piercing process creates a blind hole before the cutting process, then the cutting process can start from an established piercing, but the overall process duration increases due to the additional step

Engineering Contradiction:
Improvecutting process stabilityVSAvoidtotal process time
Core Design Contradiction:
ReliabilityVSDuration of action of moving object

Solution Approach 1:

The patent applies preliminary action by creating an initial piercing hole before the main cutting process. This preliminary piercing establishes a starting point for the subsequent cutting operation, ensuring stable and reliable cutting from a pre-formed opening. The real-time measurement and control system optimizes this preliminary piercing to be completed efficiently, minimizing the time added by this preparatory step while ensuring cutting stability.

Inventive Principle:
Principle #10Preliminary action

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 significantly reduces the duration of the piercing process, enhances the quality of the piercing hole, and improves process stability by enabling targeted adjustments of process parameters, ensuring the piercing process meets predetermined quality criteria.

Implementation Method 1

measuring a piercing depth of the piercing hole using at least one optical measuring beam during the piercing process

Methodology Applied
Scientific EffectOptical measurement: Light

Implementation Method 2

piercing a piercing hole into a workpiece using a laser beam

Methodology Applied
Scientific EffectLaser ablation: Laser Ablation

Implementation Method 3

The laser beam emitted from a laser light source or the end of a laser fiber is focused or bundled onto the workpiece to be processed

Methodology Applied
Scientific EffectLaser: Laser

Data Source

PatentEP3883720B1Method for laser processing, and laser machining system for carrying out the method
Publication Date: 2024.01.17 PRECITEC GMBH
  • EP3883720B1 patent drawingFigure 1
  • EP3883720B1 patent drawingFigure 2
  • EP3883720B1 patent drawingFigure 3

AI summary

The present disclosure relates to a method for laser machining of a workpiece (1), more particularly for laser cutting of a workpiece (1), using a laser machining system (100), comprising: piercing a piercing hole (2) into the workpiece (1) using a laser beam (10); measuring a current piercing depth of the piercing hole (2) by means of at least one optical measurement beam (13) during the piercing procedure; and setting at least one process parameter of the laser machining system (100) during the piercing procedure on the basis of the current piercing depth for the purposes of a closed-loop control of the piercing process.