Multi-Scanner Calibration via Beam Overlap and Feedback

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Solution Overview

Problem

Current additive manufacturing systems face challenges in calibrating multiple scanners effectively, particularly in addressing thermal drift and ensuring precise positioning of radiation beams during the build process.

Innovation Solution

The method involves recording detector values from radiation beams directed onto a working plane, using a reference pattern to correct beam steering optics across multiple scanners, and employing a position-sensitive device to measure radiation intensity and phase shifts, allowing for automated calibration and alignment of scanners to a common frame of reference.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If multiple scanners are used in additive manufacturing apparatus, then productivity is improved, but manufacturing precision deteriorates due to calibration difficulties and thermal drift

Engineering Contradiction:
Improvebuild speedVSAvoidbeam positioning accuracy
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The patent implements a feedback mechanism where detector values from radiation beams are recorded and used to calculate correction values that are applied back to the scanner control. This closed-loop system continuously monitors and corrects beam positioning errors, maintaining manufacturing precision while using multiple scanners for high productivity

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system dynamically adjusts scanner parameters by calculating correction values based on measured detector values and applying these corrections to scanner control. This allows the system to adapt to thermal drift and positioning errors in real-time, maintaining precision across multiple scanners operating simultaneously

Inventive Principle:
Principle #35Parameter changes

2Ease of operation

If automated calibration method is implemented, then ease of operation is improved, but device complexity increases due to additional detectors and correction mechanisms

Engineering Contradiction:
Improvecalibration automationVSAvoidscanner system complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The calibration system performs self-calibration by automatically recording detector values, calculating correction values, and applying corrections without manual intervention. The scanner system calibrates itself through this automated process, reducing operational complexity despite the added calibration infrastructure

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The detector system serves multiple functions: it monitors radiation beam positions during calibration, tracks thermal drift during operation, and provides data for correction calculations. This multi-functionality reduces the need for separate calibration devices, offsetting the added complexity with operational efficiency

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

This approach enables accurate and automated calibration of scanners, correcting for thermal drift and ensuring precise positioning of radiation beams, thereby improving the accuracy and reliability of the additive manufacturing process.

Implementation Method 1

each scanner for directing a radiation beam to a working plane

Methodology Applied
Scientific EffectElectromagnetic radiation: Radiation

Implementation Method 2

employing a position-sensitive device to measure radiation intensity and phase shifts

Methodology Applied
Scientific EffectRadiation detection: Photoelectric Effect

Data Source

PatentEP3448604B1Calibration method of plurality of scanners in an additive manufacturing apparatus
Publication Date: 2023.10.25 RENISHAW PLC
  • EP3448604B1 patent drawingFigure 1
  • EP3448604B1 patent drawingFigure 2
  • EP3448604B1 patent drawingFigure 3

AI summary

This invention concerns a method for determining an attribute of an additive manufacturing apparatus comprising a plurality of scanners, each scanner of the plurality of scanners (106a, 106b, 106c, 106d) comprising beam steering optics (121a, 121b, 121c, 121d) for directing a corresponding radiation beam (118a, 118b, 118c, 118d) to a working plane in which material is consolidated in layers. The method may comprise controlling the beam steering optics (121a, 121b, 121c, 121d) of a pair of the scanners (106a, 106b, 106c, 106d) such that a first scanner of the pair directs a radiation beam to form a feature (202, 205, 213) in the working plane and the feature is within a field of view (201, 204) of a detector (123a, 123b, 123c, 123d) of the second scanner of the pair, the detector (123a, 123b, 123c, 123d) for detecting radiation coming from the working plane that is collected by the beam steering optics (121a, 121b, 121c, 121d) of the second scanner (106a, 106b, 106c, 106d). Additionally or alternatively, the method may comprise controlling the beam steering optics (121a, 121b, 121c, 121d) of first and second scanners (106a, 106b, 106c, 106d) of a pair of the scanners (106a, 106b, 106c, 106d) such that fields of view (208, 209, 211, 212) of the working plane for the detectors (123a, 123b, 123c, 123d) of the first and second scanners (106a, 106b, 106c, 106d) at least overlap.