A comprehensive review on integrating vision-based sensing in extrusion-based 3D printing processes: toward geometric monitoring of extrusion-based 3D concrete printing

In recent years, research on extrusion-based 3D concrete printing (3DCP) has gained traction. Ongoing research aims to improve sustainability and accuracy of 3DCP as maintaining print quality and material consistency during the process remains a challenge. To address this challenge, vision-based sensing technologies have been implemented as monitoring and controlling systems. This paper presents a systematic review on the use of vision-based sensing technologies primarily in 3DCP, as well as extrusion-based 3D printing with other materials. The goal is to provide a comprehensive analysis of the implementation and effectiveness of the vision-based sensing technologies in enhancing the accuracy and stability of 3DCP. With a focus on the technologies and methodologies employed, the paper presents the trends and gaps in the analyzed literature, centering on 3DCP. The literature reviewed suggests that implementing vision-based sensing technologies as monitoring systems can improve the accuracy and structural stability of the printed parts, which results in increased safety and decreased material waste, environmental impact, time, and labor.