Real-time Feature Management in Multi-ply AFP Deposition

acm7 Tracking Number 11

The study presents a novel real-time control algorithm for managing the quality of multi-ply Automated Fibre Placement (AFP) deposition, with a focus on common AFP features such as overlaps. While Automated Fibre Placement (AFP) is a critical manufacturing process for high-performance composite structures, 50% of the process time is consumed by inspection and rework steps [1]. Furthermore, depositions can feature a wide range of CFRP materials and underlying geometries, leading to common AFP defects, such as puckering, and features, such as gaps and overlaps. The study addresses these variabilities through real-time control. The study investigates the effects of key process parameters -compaction force and tow tension- on overlaps in a replicated AFP deposition scenario, illustrated in Figure 1. This characterisation work was conducted on an in-process sensing system, which included pre- and post-deposition laser line scanners. Features such as overlaps and their effect on the subsequent ply were quantified using the two complementary sensors shown in Figure 2. Based on the characterisation experiments, a novel automated, in-process monitoring and rework algorithm for multi-ply AFP defects was developed. Furthermore, a feed-forward control strategy was implemented to "pre-sense" upcoming features during multi-ply deposition, enabling the proactive adjustment of process parameters in real time. This integrated system was demonstrated to be capable of tuning process parameters for the given deposition scenario. The closed-loop control system developed is a significant step towards fully autonomous and defect-free composite manufacturing, enhancing preform quality, reducing waste, and increasing the reliability of the AFP process. [1] F. Heinecke and C. Willberg, “Manufacturing-induced imperfections in composite parts manufactured via automated fiber placement,” Journal of Composites Science, vol. 3, pp. 1– 24, 2019.