Alexander Oleff

Project engineer
Practice Areas:
Additive manufacturing, robotics / handling, image processing
+49 (0)511 279 76-224


Qualitative uncertainties are a key challenge for the further industrialization of additive manufacturing. To solve this challenge, methods for measuring the process states and properties of parts during additive manufacturing are essential. The subject of this review is in-situ process monitoring for material extrusion additive manufacturing. The objectives are, first, to quantify the research activity on this topic, second, to analyze the utilized technologies, and finally, to identify research gaps. Various databases were systematically searched for relevant publications and a total of 221 publications were analyzed in detail. The study demonstrated that the research activity in this field has been gaining importance. Numerous sensor technologies and analysis algorithms have been identified. Nonetheless, research gaps exist in topics such as optimized monitoring systems for industrial material extrusion facilities, inspection capabilities for additional quality characteristics, and standardization aspects. This literature review is the first to address process monitoring for material extrusion using a systematic and comprehensive approach.

Material extrusion, Fused deposition modeling, Process monitoring, Sensor technology, Research gaps

How can additive process chains be automated and print quality monitored? How is a component made of metal and plastic created in multi-material printing? Scientists from Lower Saxony ADDITIV have been researching this and more in the past three years.

additive manufacturing, 3d printing, automation, quality assurance

Quality assurance methods are a central success factor for the further industrialization of additive manufacturing. This paper presents an approach for an optical inspection system that controls the quality of additive material extrusion layer by layer. The inspection task gets analyzed, hardware components for data acquisition are designed and a first step towards texture-analytical detection of defects is presented.

additive manufacturing, 3d printing, material extrusion, fused deposition modeling, image processing

Quality assurance methods are a central success factor for the further industrialization of additive manufacturing. In the IGF research project "Optical quality inspection for extrusion 3D printing (Quali3D)", a testing system is therefore being developed which monitors the quality of the additive process layer by layer. This should enable a comprehensive evaluation.

3D printing, additive manufacturing, optical metrology, image processing

By automating process steps, additive manufacturing can be integrated into industrial value chains. The Institut für Integrierte Produktion Hannover (IPH) gGmbH has been designing a process chain linking 3d printers and mounting stations automatically.

additive manufacturing, 3D printing

For companies it is challenging to identify application scenarios for Industry 4.0 as well as to use the associated potential. This article describes a strategy, which includes methodical and knowledge-based guidelines for decisions, to increase the likelihood of beneficial industry 4.0 transformations.

industry 4.0, strategy, production system

The use of 3D printing techniques gives manufacturing companies the opportunity to implement new production processes and to unlock economic potentials. In this article a research project is presented, which aims to analyse the use of build-operate-transfer models with 3D printers. Thereto an evaluation and implementation tool for build-operate-transfer models is being designed, which considers the perceptions of the suppliers and the costumers.

3D printer, build-operate-transfer models, production organization, profitability, production logist

Research projects