Monitoring and detection of defects in additive manufacturing based on multi-sensor and data fusion technology
Additive manufacturing has been an enabling process for generating complex components with the advantages of fast prototyping and short product cycling in wide applications. During the additive process such as Selective Laser Melting (SLM), defects exist which will thereafter affect the performance of the final product. The process monitoring for additive manufacturing become critically important to detect such defects and hence provide information for processing diagnosis and parameters optimization. However, due to the complex and severe conditions such as high temperature, glare and dust influence, it is difficult to obtain comprehensive information of the melting areas and related microstructures. Future more, the complicated morphological structures in the surface of additive manufactured parts lead to the difficulties to identify and characterize such defects. To address those problems, this talk will present a monitoring and detection system with multi-sensors with a broad spectrum such as visible light, inferred and polarized spectrum. Optical design of the monitoring system is presented and the simulational performance is evaluated. Different defects in additive manufacturing have been studied and analyzed. Deep leaning algorithm based on improved YOLOv3- MobileNetv3 is adopted for data fusion from different spectrum imaging to identify these defects. A series of experimental studies are carried out and results are shown and discussed. Prospective trend for future studies in multi-sensor and data fusion for additive manufacturing process monitoring is also presented.
Prof L.B. Kong got his BEng and MEng degrees from Harbin Institute of Technology, and PhD degree from The Hong Kong Polytechnic University. Currently he is a full professor and deputy director of Shanghai Engineering Research Center of Ultra-precision Optical Manufacturing of Fudan University. Prof. Kong has been engaged in ultra-precision optical manufacturing and measurement for nearly twenty years. His research interests include ultra-precision machining technology, intelligent vision measurement, process modeling and optimization, freeform machining and measurement, design and generation of functional structures, multi-spectrum and vision inspection, etc. He has led/participated in a series of national research projects and industrial collaborative projects. He has published over 150 research papers, got over 20 granted patents, and a series of book chapters. As an active researcher, Prof. Kong has received Technology Progress Award from Ministry of Education of China, Faculty Awards for Outstanding Performance/Achievement from The Hong Kong Polytechnic University, Invited Young Researcher from Asia Society for Precision Engineering and Nanotechnology, Joseph Whitworth Prize and A M Strickland Prize from Institution of Mechanical Engineers of UK, Geneva Invention Awards, etc. He is the chairman of Advanced Optical Manufacturing Committee (Young) in COES, the editorial board members of Chinse Journal of Mechanical Engineering and International Journal of Extreme Manufacturing, etc.