The main problem of the extrusion bio 3D printing method is the lack of direct control of the manufacturing process, which limits the accuracy of the printed structure and the design complexity. The lack of direct control of the process can lead to many defects, which affect the appearance and function of the manufactured structure. Because the axis movement of the machine cannot accurately predict the material deposition position, and the additional sensing during the material extrusion process required for precise manufacturing.
Researchers from the Department of Mechanical Science and Engineering at the University of Illinois at Urbana-Champaign have proposed a cyclic iterative process monitoring system that can perform direct manufacturing process control in the material deposition reference system. In order to reduce the dimensional error of the parts in the manufacturing process, they integrated a non-contact laser displacement scanner into the printing platform, as shown in Figure 1.
After the initial print is made using the designed reference trajectory, the laser scanner will move on the part to measure the position of the material. Use their self-made image processing algorithm to compare the laser scanner data with the designed reference trajectory to generate an error vector. To compensate for the measured error, the algorithm modifies the axis reference trajectory for the second printing iteration. The process is shown in Figure 2.
Through the integration of printing process monitoring and error compensation technology on a 3D printing platform, the research results show that this method can improve the material deposition position.
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