Laser Machining Head Sensor Calibration for Chromatic Aberration
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In scanner-based laser machining systems, chromatic aberration causes the beam path of optical sensors to be directed to a point other than the target position in the scan field, leading to inaccuracies in measurement and monitoring of the laser machining process.
Innovation Solution
A method for calibrating at least one optical sensor of a laser machining head involves deflecting the beam path of the optical sensor to various positions, generating optical measurement signals, and determining correction values based on deviations from the target position. These correction values are used to adjust the measurement position of the optical sensor, ensuring accurate monitoring and machining.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the beam path of the optical sensor is directed through the deflection device and focusing device, then the measurement position can be adjusted to different locations in the scan field, but chromatic aberration causes the measurement position to deviate from the target position
Solution Approach 1:
The patent applies preliminary action by performing calibration before actual measurement. A calibration routine is executed that directs the optical sensor beam path to known reference positions on a calibration target, measures the actual positions, and calculates correction values in advance. These correction values are stored and applied during subsequent measurements to compensate for chromatic aberration, thereby resolving the position accuracy issue while maintaining measurement position adaptability.
Solution Approach 2:
The patent applies parameter changes by modifying the beam path parameters through the calibration process. By measuring the actual positions of the beam path at different deflection angles and wavelengths, and calculating correction values that adjust these parameters, the system compensates for chromatic aberration. The correction values effectively change the beam path parameters to align the measurement position with the target position despite the optical system's inherent aberrations.
2Adaptability or versatility
If chromatic aberration is present in the optical system, then different wavelengths are focused at different positions, but this causes the optical sensor to measure at incorrect positions relative to the laser beam
Solution Approach 1:
The patent applies feedback by using the optical sensor to monitor the machining process and provide information back to the control system. The sensor detects process characteristics at the measured position, and this feedback is used to assess machining quality and make adjustments. The calibration process ensures that this feedback is accurate by correcting for chromatic aberration, so the sensor truly reflects conditions at the laser beam's interaction point with the workpiece.
Solution Approach 2:
The patent replaces mechanical alignment adjustments with an optical calibration approach. Instead of physically adjusting the optical components to eliminate chromatic aberration, the system uses computational methods to calculate and apply correction values based on optical measurements. This substitution of mechanical adjustment with optical-measurement-based correction maintains system adaptability while improving positioning accuracy.
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
The calibration method improves the accuracy of optical sensor measurements, ensuring that the measurement position aligns with the intended target position, thereby enhancing the reliability and precision of the laser machining process.
Implementation Method 1
A laser beam coupled into the laser machining head may be deflected to different positions of a workpiece by the deflection device
Implementation Method 2
The laser beam may be focused on the workpiece by means of the focusing device
Implementation Method 3
A beam path of the optical sensor may partially extend coaxially with the beam path of the laser beam and also pass through the focusing device
Data Source
AI summary
A method for calibrating at least one optical sensor of a laser machining head is provided. The laser machining head comprises a first optical sensor, a deflection device, and a focusing device. A laser beam path of the first optical sensor passes through the deflection device and the focusing device. The method comprises the steps of: deflecting the beam path of the first optical sensor by the deflection device to a first position on a first reference; generating a first optical measurement signal based on measurement light received by the first optical sensor from the first position on the first reference; and determining a correction value for calibrating the first optical sensor based on the first optical measurement signal and according to a deviation of the first position on the first reference from a first target position, which is specified relative to a position of the machining laser beam.