Laser Cutting Contour Checking Using Camera Path Reconstruction
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Solution Overview
Problem
Laser cutting machines face challenges in achieving both high productivity and accuracy, particularly in cutting corners and small radii, due to inertia, vibrations, and environmental factors, leading to path deviations and reduced productivity.
Innovation Solution
A computer-implemented method using a reference texture applied along the target path, captured by a camera, to reconstruct the actual path and calculate deviations, allowing for real-time compensation of contour errors before cutting.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If cutting speed is increased to improve productivity, then productivity is improved, but path accuracy deteriorates due to overshooting from inertia
Solution Approach 1:
The system performs preliminary measurement of the actual cutting path using a camera and reference texture during a test run at the intended cutting speed. Based on this measurement, compensation values are calculated in advance to correct for inertia-induced overshooting. The compensated path is then used for actual cutting, allowing high cutting speeds to be maintained while achieving accurate contours through pre-calculated corrections.
2Manufacturing precision
If dynamic limits are restricted to maintain path accuracy, then manufacturing precision is improved, but productivity deteriorates
Solution Approach 1:
The system uses a camera to capture the actual cutting path and compares it with the target path to measure deviations. These measurements provide feedback about the machine's dynamic behavior at different speeds and accelerations. Based on this feedback, compensation values are calculated and applied to the cutting path, enabling the system to maintain high cutting speeds while achieving accurate contours through continuous measurement and correction.
3Ease of manufacture
If internal encoder measurement systems are used to measure position, then measurement is simplified, but measurement precision deteriorates because they cannot account for inertia and flexibility
Solution Approach 1:
The system introduces a camera and reference texture as an intermediary measurement system. Instead of relying solely on internal encoders that cannot capture dynamic effects, the camera optically measures the actual cutting path with high precision. This external measurement system serves as a mediator between the cutting process and the control system, providing accurate position data that accounts for inertia and flexibility without requiring complex modifications to the machine's internal measurement systems.
Data Source
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AI summary
In one aspect, the present invention relates to a contour checking device (1000) for calculating path deviations from a target path (SB) of a cutting head (10) of a laser machine tool. The contour checking device (1000) comprises a reference texture interface (100) for reading a reference texture (RT) along the target path (SB), which is defined in particular for cutting a contour, a controller (200), which is intended for controlling the laser machine tool in such a way that the cutting head (10) traverses the target path (SB); at least one camera (K), wherein the controller for controlling the at least one camera (K) is intended for continuously capturing overlapping frames of the reference texture (RT) along the traversed path; a processor (300), which is intended for executing an image processing algorithm for reconstructing the trajectory traversed by the cutting head from the captured overlapping frames of the reference texture (RT); and wherein the processor (300) is intended for calculating deviations between the reconstruction of the path traversed by the cutting head and the target path (SB). The contour checking device (1000) also comprises an output interface (400), which is intended for outputting the calculated deviations.