Research on integrated motion and vibration control methods for heated nozzles in space additive manufacturing equipment

In microgravity and disturbance-rich orbital environments, the thermal nozzle of Delta-type space-based fused deposition modeling (FDM) systems is prone to trajectory deviations and vibration-induced defects, which can severely degrade the surface quality and mechanical integrity of printed parts. To address this problem, an integrated motion-vibration control strategy is proposed. The motion loop employs a classical PID controller for accurate trajectory tracking, whereas the vibration loop adopts a Filtered-X Least Mean Square (FXLMS) algorithm with a nonlinear variable step-size scheme jointly modulated by exponential decay and sinusoidal functions. The proposed step-size mechanism improves convergence behavior and robustness under time-varying disturbances by enabling fast initial adaptation while maintaining stable steady-state performance. A high-fidelity ADAMS-Simulink co-simulation platform is developed for comparative evaluation. The results show that the proposed strategy reduces micro-vibration amplitudes, improves tracking accuracy, and provides stronger robustness than fixed-step adaptive approaches, thereby offering an effective solution for high-precision space-based additive manufacturing.