7-days of FREE Audio papers, translation & more with Prime
7-days of FREE Prime access
7-days of FREE Audio papers, translation & more with Prime
7-days of FREE Prime access
https://doi.org/10.1016/j.addma.2021.101951
Copy DOIJournal: Additive Manufacturing | Publication Date: Mar 22, 2021 |
Citations: 11 | License type: other-oa |
Fused filament fabrication (FFF) continues to be among the most widespread additive manufacturing process for making polymeric functional prototypes, and in several cases end-use parts. There is a large installed base of serial-link industrial robots, some of which could be potentially retrofitted with an extruder head as an end-effector to serve as FFF systems with as many as six degrees of freedom compared to 3-axis gantry mechanisms that are typically deployed today. This paper identifies and proposes solutions to key engineering challenges that arise in retrofitting such robotic FFF systems in terms of integrating robot motion controller with extruder controller and evaluating the quality of the fabricated parts. Specifically, we propose an approach for integration and real-time synchronization of controllers to ensure that the extrusion velocity and deposition velocity match closely by building upon an analytical model for predicting road geometry as a function of process parameters. Compared to gantry mechanisms, this is challenging in serial-link industrial robots because of significantly larger and space-variant inertias. Furthermore, to compensate for distortion in the bed surface of the retrofitted robotic FFF system, a bed compensation algorithm based on bilinear interpolation has been developed. We have engineered a fully functional research testbed in which integration and real-time synchronization of controllers is achieved by (1) communicating space-variant process parameters in real-time using TCP/IP sockets, and (2) analog and digital I/O interfacing. Experimental testing shows excellent (R2 = 0.9983) agreement between requested and actual volumetric flow rates and less than 5% errors in extrusion widths and heights in test samples fabricated across the range of physical limits of FFF process parameters. The testbed is also evaluated in terms of the impact of controller synchronization on the part dimensional accuracy for simple and complex geometries. This work can serve as a basis for further engineering innovations towards cost-effectively harnessing the capacity of industrial robots to manufacture geometrically accurate parts using FFF.
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.