Machine Vision Calibration for Additive Fabrication Precision

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Additive fabrication devices face challenges in ensuring accurate object representation due to incorrect build platform orientation, calibration complexity, and limitations in fabricating objects on non-flat surfaces, with imperfections often going undetected during the process.

Innovation Solution

Integration of machine vision systems within additive fabrication devices to provide real-time feedback for calibration, surface sensing, and adjustment of printhead positions, allowing for precise alignment and compensation of imperfections during the fabrication process.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If traditional additive fabrication is used without machine vision, then the device complexity is low, but the manufacturing precision deteriorates due to incorrect build platform orientation and undetected imperfections

Engineering Contradiction:
Improveobject representation accuracyVSAvoidcalibration complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The machine vision system continuously monitors the build platform orientation and object fabrication process, providing real-time feedback to the control system. This feedback loop enables automatic detection of orientation deviations and imperfections, allowing the system to self-correct without manual intervention, thereby improving manufacturing precision while managing calibration complexity through automation

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent replaces manual mechanical calibration procedures with an automated machine vision-based optical measurement system. Instead of relying on physical alignment tools and human operators to calibrate the build platform, the system uses cameras and image processing algorithms to detect and correct orientation errors, substituting mechanical calibration with optical sensing and computational correction

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Manufacturing precision

If machine vision systems are integrated for real-time monitoring, then the manufacturing precision improves, but the device complexity increases

Engineering Contradiction:
Improvedetection accuracyVSAvoidsystem integration complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The machine vision system is designed to perform multiple functions: monitoring build platform orientation, detecting object imperfections, measuring dimensions, and guiding corrections. By consolidating these diverse functions into a single integrated system rather than separate specialized devices, the patent reduces overall system complexity while maintaining high detection accuracy across multiple parameters

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

Solution Approach 2:

The machine vision system automatically detects and reports orientation errors and imperfections without requiring external inspection equipment or manual measurement tools. The system serves itself by providing the data needed for its own calibration and for controlling corrections, eliminating the need for separate complex measurement and control systems

Inventive Principle:
Principle #25Self-service

3Manufacturing precision

If build platform orientation is not correctly calibrated, then the ease of operation is maintained, but the manufacturing precision deteriorates

Engineering Contradiction:
Improvelayer consistencyVSAvoidcalibration effort
Core Design Contradiction:
Manufacturing precisionVSEase of operation

Solution Approach 1:

The machine vision system performs preliminary detection and measurement of build platform orientation before fabrication begins. By identifying and reporting orientation deviations in advance, the system allows operators to correct issues before they affect manufacturing precision, maintaining both ease of operation and layer consistency through proactive rather than reactive calibration

Inventive Principle:
Principle #10Preliminary action

4Manufacturing precision

If traditional fabrication methods are used on non-flat surfaces, then the device complexity is low, but the manufacturing precision deteriorates due to inability to detect imperfections

Engineering Contradiction:
Improvesurface qualityVSAvoidsurface sensing capability
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The machine vision system continuously monitors the build platform surface and detected imperfections, providing real-time feedback that enables dynamic adjustment of fabrication parameters. This feedback mechanism allows the system to compensate for surface irregularities by modifying deposition patterns, ensuring consistent surface quality even when fabricating on non-flat surfaces

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system detects and characterizes imperfections at specific locations on the build platform surface, then applies localized corrections only where needed rather than requiring uniform calibration across the entire surface. This local quality approach allows precise correction of specific imperfections while maintaining ease of operation and reducing overall system complexity

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP3194145B1Systems and methods of machine vision assisted additive fabrication
Publication Date: 2022.06.29 MASSACHUSETTS INST OF TECH
  • EP3194145B1 patent drawingFigure 1
  • EP3194145B1 patent drawingFigure 2
  • EP3194145B1 patent drawingFigure 3

AI summary

The present application relates generally to systems and methods for using machine vision to provide information on one or more aspects of an additive fabrication device, such as calibration parameters and/or an object formed by the device or in the process of being formed by the device. According to some aspects, a method is provided for calibrating an additive fabrication device. According to some aspects, a method is provided for assessing at least a portion of an object formed using an additive fabrication device. According to some aspects, a method is provided for fabricating a second object in contact with a first object using an additive fabrication device. According to some aspects, an additive fabrication device configured to perform one or more of the above methods may be provided.