A Procedure to Integrate a CIS Sensor in an Additive Manufacturing Machine for In-Situ Digitizing of Deposited Material Layers

A notable constraint to the industrial application of additive manufacturing processes is the lack of geometric accuracy of the parts produced. In-situ inspection systems, therefore, need to be developed to detect and compensate for any geometric deviations that appear during the process. This article proposes a noncontact system for the digitization of deposited material layers, based on a contact image sensor extracted from a low-cost flatbed paper scanner. The viability of using this sensor for such a purpose was analyzed by integrating it in a tailor-made test bench with the dual capability of fused filament fabrication and digitizing of deposited layers. The integration procedure includes analysis of the sensor's operating principle, development of the hardware and control routines required for PC operation, and image processing. To validate the integration, two specimen parts were built and digitized in the test bench. The measurements performed on the captured images showed low discrepancies with respect to those obtained on a coordinate measuring machine.