Multi-Beam 3D Printing Workload Balancing Using Huffman Coding

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Solution Overview

Problem

Existing additive manufacturing methods face inefficiencies due to uneven workload distribution among energy beams when producing multiple objects with varying shapes and dimensions, leading to increased manufacturing time and downtime, as manual assignment of irradiation tasks is laborious and time-consuming, and difficult to optimize for minimum overall manufacturing time.

Innovation Solution

The method employs Huffman coding to automatically assign parts of layers to energy beams based on estimated irradiation times, ensuring an equal distribution of workload by generating a Huffman tree that groups parts with similar irradiation times, allowing for optimal allocation of energy beams across the manufacturing process.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If manual assignment of layers to energy beams is used, then the apparatus can operate with multiple energy beams, but the workload distribution becomes uneven leading to increased manufacturing time

Engineering Contradiction:
Improvemanufacturing timeVSAvoidworkload distribution
Core Design Contradiction:
ProductivityVSEase of operation

Solution Approach 1:

The system automatically performs workload assignment and optimization without requiring manual user input. The control unit autonomously calculates and distributes layers to energy beams based on real-time writing time estimates, eliminating the need for manual assignment while achieving optimal load balancing

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The system performs preliminary estimation of writing times for each layer before actual manufacturing begins. By pre-calculating the workload distribution and assigning layers to energy beams in advance based on these estimates, the system optimizes manufacturing time without requiring manual intervention during the process

Inventive Principle:
Principle #10Preliminary action

2Device complexity

If entire objects are assigned to single energy beams, then the assignment process is simple, but the distribution of irradiation time becomes uneven causing beam downtime

Engineering Contradiction:
Improveassignment processVSAvoidirradiation time distribution
Core Design Contradiction:
Device complexityVSProductivity

Solution Approach 1:

The system segments objects into individual layers and further divides layers into parts that can be independently assigned to different energy beams. This segmentation allows fine-grained control over workload distribution, enabling the system to balance irradiation time across multiple beams while maintaining a relatively simple assignment process

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system dynamically adjusts the assignment of layers to energy beams based on real-time writing time estimates. Rather than using static assignment rules, the control unit continuously evaluates and optimizes the distribution, adapting to varying layer complexities and beam performance characteristics

Inventive Principle:
Principle #15Dynamics

3Ease of operation

If user manually estimates writing time for objects, then the assignment can be made, but the overall minimum manufacturing time is difficult to find

Engineering Contradiction:
Improveassignment capabilityVSAvoidmanufacturing time optimization
Core Design Contradiction:
Ease of operationVSProductivity

Solution Approach 1:

The system implements a feedback mechanism where writing time estimates are continuously refined based on actual manufacturing data. The control unit uses estimated writing times to make initial assignments, then adjusts these estimates based on real-time performance feedback, progressively converging on the optimal manufacturing time

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system replaces manual user estimation with an automated computational approach. The control unit uses algorithms to calculate writing time estimates and optimize layer assignment, substituting human judgment with precise computational analysis that can evaluate multiple scenarios and identify the optimal manufacturing time

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

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 reduces overall manufacturing time by ensuring equal distribution of workload among energy beams, minimizing downtime, and optimizing the assignment of parts to energy beams, thereby improving the efficiency of the additive manufacturing process.

Implementation Method 1

additively manufacturing of three-dimensional objects by means of successive layerwise selective irradiation and consolidation of layers of a build material which can be consolidated by means of an energy beam

Methodology Applied
Scientific EffectSelective Laser Sintering: Selective Laser Sintering

Implementation Method 2

irradiating layers of the object in a build plane... irradiated by a first energy beam... irradiated by another energy beam

Methodology Applied
Scientific EffectLaser heating: Laser

Data Source

PatentEP3474199B1Method for operating an apparatus for additively manufacturing of three-dimensional objects
Publication Date: 2021.05.05 CL SCHUTZRECHTSVERW
  • EP3474199B1 patent drawingFigure 1
  • EP3474199B1 patent drawingFigure 2

AI summary

Method for operating at least one apparatus (1) for additively manufacturing of three-dimensional objects (2 - 5) by means of successive layerwise selective irradiation and consolidation of layers (6) of a build material which can be consolidated by means of an energy beam (12), wherein at least one object (2 - 5) is being built by successively irradiating layers (6) of the object (2 - 5) in a build plane (13), wherein at least one part (16 - 31) of at least one layer (6) of the object (2 - 5) is assigned to be irradiated by a first energy beam (12) and at least one other part (16 - 31) of at least one layer (6) of the object (2 - 5) is assigned to be irradiated by another energy beam (12), wherein the parts (16 - 31) of layers (6) are assigned to be irradiated by one of the at least two energy beams (12) based on a Huffman coding.