Moving Detection Device for Laser Cutting Process Light Monitoring

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing laser cutting machines with stationary workpieces cannot perform reliable process monitoring using a fixed CCD camera, as the camera's position remains constant while the workpiece moves, preventing effective detection of process light during the cutting process.

Innovation Solution

A method and device where a beam-catching device, potentially a line or point catcher, moves in conjunction with the cutting device, allowing a detection device to follow and maintain a constant distance from the cutting beam, enabling the detection of process light from underneath the workpiece. This includes using sensor elements like photodiodes or CCD cameras to evaluate changes in brightness and position, ensuring reliable monitoring of the cutting process.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a fixed CCD camera is used for process monitoring, then the camera structure is simple and stationary, but it cannot track the moving cutting beam and maintain constant detection distance

Engineering Contradiction:
Improveprocess monitoring reliabilityVSAvoiddetection device structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The detection device is made movable to track the cutting beam dynamically. The camera is mounted on a moving platform that follows the beam's position, allowing the detection distance to remain constant while the beam moves across the workpiece. This dynamic configuration ensures reliable process monitoring without requiring the camera to be stationary.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

A moving platform or carriage is introduced as an intermediary between the stationary camera and the moving cutting beam. This intermediary carries the camera and moves synchronously with the beam, maintaining a constant detection distance while enabling the camera to follow the beam's trajectory throughout the cutting process.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If the workpiece is moved during cutting, then process monitoring with a stationary camera is possible, but the workpiece positioning and movement system becomes more complex

Engineering Contradiction:
Improveprocess monitoring capabilityVSAvoidworkpiece positioning system
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

Instead of moving the workpiece to enable monitoring, the detection device is moved to follow the stationary or slowly positioned workpiece. This inverts the conventional approach: rather than making the workpiece move through the detection zone, the detector moves through the workpiece's coordinate system, maintaining constant distance from the cutting beam while the workpiece remains relatively stationary.

Inventive Principle:
Principle #13The other way round (Inversion)

3Measurement precision

If the detection device follows the cutting beam, then constant detection distance is maintained, but the detection device and its movement system become more complex

Engineering Contradiction:
Improvedetection distance consistencyVSAvoiddetection device movement mechanism
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The detection device is merged with the existing beam delivery or positioning system. The camera is integrated into the cutting head assembly or mounted on the same moving carriage that positions the cutting beam, so that the detection device's movement is coupled to the beam's movement through a shared mechanical structure, reducing the need for separate complex movement mechanisms.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The moving platform or carriage is designed to serve multiple functions: it carries both the cutting beam delivery system and the detection device, and provides the movement capability for both. This multi-functional design eliminates the need for separate movement mechanisms for the beam and the detector, reducing overall system complexity while maintaining constant detection distance.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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

Enables reliable detection of miscuts and cut quality assessment, allowing for real-time process control and intervention in the cutting process, even for large or heavy materials, by maintaining consistent detection conditions and compensating for changes in the position of the process light.

Implementation Method 1

the process light emerging on the underside is detected by a detection device with at least two sensor elements located opposite one another

Methodology Applied
Scientific EffectLight detection: Photoelectric Effect

Data Source

PatentEP2164672B1Method for detecting a process light during a separation process in sheet material and device for carrying out the method
Publication Date: 2015.05.06 TRUMPF WERKZEUGMASCHINEN GMBH & CO KG
  • EP2164672B1 patent drawingFigure 1
  • EP2164672B1 patent drawingFigure 2
  • EP2164672B1 patent drawingFigure 3

AI summary

The invention relates to a method for detecting a process light during a separation process in sheet material (12) and a device for carrying out the method, wherein a separating device (18) is produced with a cutting beam (22), sad cutting beam (22) of the separating device (18) is directed at an upper surface of the sheet material (12), which exits from the underside of the sheet material after formation of a cut gap (32). The process light exiting from the underside of the sheet material (12) during the cutting process is detected by a detection device (31) arranged beneath the sheet material (12), wherein the separating device (18) is moved in a t least the X and Y direction during the separation process and independently of the changing position of the process light exiting from the underside, within a plane of a workpiece support (16) the same is detected by activation of the detection device (31).