A Multi-Inlet Extrusion System for Closed-Loop Spatial Profile Control in Large-Format Additive Manufacturing
Angelica Coronado Preciado, Brian Parrott, Eric Feron
AI summary
Problem
Conventional single-inlet feeds for rectangular nozzles induce lateral pressure gradients that cause uneven deposition, center bulging, and poor control during dynamic trajectories.
Approach
The system replaces the single feed with three independently actuated syringe inlets that function as a programmable fluid manifold, actively steering material flow and using in-line laser profilometry for continuous cross-sectional feedback.
Key results
- 33% reduction in total input flow for steady-state extrusion
- 78% lower plunger velocity per actuator compared to single-inlet baseline
- High-resolution lateral steering via differential inlet actuation
- 100% versatility and ≥85% allocation efficiency under simulated outlet blockages
Why it matters
This architecture provides the hardware and sensing foundation for scalable, dynamically reconfigurable nozzles and closed-loop control in large-format robotic additive manufacturing.
Abstract
Rectangular nozzles are attractive for large- format additive manufacturing (LFAM) due to their improved deposition efficiency. However, single-inlet feeding of high- aspect-ratio nozzles inherently induces lateral pressure gradi- ents, causing center-heavy flow and eliminating localized control during dynamic trajectories. We introduce a distributed multi- inlet extrusion testbed featuring three independently actuated inlets. Functioning as a programmable fluid manifold, this architecture actively manages the internal flow field. In-line laser profilometry is integrated as a continuous state estimator to quantify cross-sectional bead geometry. Experiments confirm this distributed architecture regularizes flow, achieving nominal steady-state extrusion with 33% less input flow and a 78% re- duction in required plunger velocity per actuator compared to a single-inlet baseline. Furthermore, differential actuation enables high-resolution lateral steering and improves deposition under simulated outlet constraints with high allocation efficiency. This work establishes the hardware and state-estimation foundation for dynamically reconfigurable nozzle outlets by mapping inputs to spatial outputs.