Automated Building Platform Alignment in Additive Manufacturing
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Solution Overview
Problem
In laser-based additive manufacturing, the alignment and zero position of the building platform are often manually adjusted, which is unsafe when the platform is heated, and existing methods for detecting misalignment are either pattern-dependent or require additional sensors, posing safety and cost concerns.
Innovation Solution
A method and device for detecting the tilt and zero position of a building platform using iterative powder layer application and removal processes, with image capture and processing to determine the powder boundary lines, allowing for automated alignment independent of structural patterns and additional sensors, utilizing a camera and control unit to generate control signals for positioning.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If manual alignment of the building platform is performed, then the alignment and zero position can be determined, but working safety is compromised when the platform is heated
Solution Approach 1:
The patent replaces manual mechanical alignment with an automated optical measurement system. A camera captures images of the building platform at different heights, and image processing algorithms automatically determine the platform's alignment and zero position, eliminating the need for manual intervention near heated components.
Solution Approach 2:
The patent introduces an intermediary measurement system consisting of a camera and image processing unit that indirectly measures the building platform's alignment. Instead of direct manual contact with the heated platform, the system uses optical images to capture platform features and calculate alignment parameters through computational methods.
2Measurement precision
If additional sensors are added for misalignment detection, then measurement capability is improved, but device complexity and cost increase
Solution Approach 1:
The patent makes the existing camera system multi-functional by enabling it to perform both standard manufacturing monitoring and alignment measurement tasks. The same camera that captures images during the additive manufacturing process is also used to detect the building platform's alignment, eliminating the need for separate alignment sensors.
Solution Approach 2:
The system uses its own existing imaging infrastructure to perform alignment measurements. The camera and image processing capabilities already present in the additive manufacturing device are repurposed to automatically measure platform alignment, making the system self-sufficient without requiring external measurement equipment.
3Measurement precision
If structural patterns are placed on the building platform for detection, then alignment measurement is enabled, but manufacturing complexity and cost increase
Solution Approach 1:
The patent utilizes optical contrast differences between the building platform and surrounding areas in captured images. Instead of adding physical patterns, the system detects alignment by analyzing variations in image intensity and features that naturally exist or are created by the lighting and platform geometry during the additive manufacturing process.
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 safe and cost-effective automated alignment of the building platform, reducing the risk of misalignment errors and component defects, while being independent of special patterns and optical conditions, and can be retrofitted into existing SLM machines without additional components.
Implementation Method 1
capturing a plurality of images of the working surface in the region of the substrate
Data Source
AI summary
A method for producing a control signal for positioning a holder of a solid freeform fabrication device that is height-adjustable relative to a working surface, comprising arranging a structural platform on the holder; capturing a plurality of images of the working surface in the region of the holder, an image-specific height of the holder being adjusted before the detection of one of the plurality of images, and depending on the change of direction in the height, a powder layer is applied or removed; determining a powder boundary line between a powder-free region and a powder-covered region of the structural platform for at least two of the plurality of images, captured for differently adjusted image-specific heights of the holder, and producing a control signal for positioning the holder on the basis of the at least two powder boundary lines. The holder can be aligned according to the control signal.