Improving Ink Feedback Control System for Vision Controlled Jetting 3D Printer

Abstract

Vision-Controlled Jetting (VCJ) is one of the 3D-printing techniques that operates by repeatedly depositing photopolymer materials in 2 dimensions onto a printing plane, solidifying them using UV light, and scanning the printing plane’s topography to readjust the printing layer accordingly. It has a high printing resolution while also maintaining high printing speed, so it is suitable for prototyping or manufacturing parts that require high precision. However, to maintain its dimensional accuracy while printing in a noisy environment, it requires the usage of a noise-robust ink controller algorithm to generate an appropriate printing layer based on the scanning information. The current VCJ controller algorithm, not able to tolerate a systematic hardware misalignment, sometimes generates printing artifacts which deform or destroy the printed part. Our work aims to answer the question of which feedback control systems of VCJ printers can adapt their printing behavior to avoid such artifacts better than the original algorithm. We propose a new algorithm, called the Image Fitting algorithm, that can detect and allow the controller to react to the hardware misalignment. We first created a VCJ printing simulator based on the real VCJ printing process. Then, we tested the controller’s ability to correct the printing artifacts against the printing simulator. The results shows that the Image Fitting algorithm can react to the hardware misalignment both in the VCJ printing simulator and during the actual physical printing process.