Nut-Driven Transmission Force Controllable Motion Platform for Suppressing Low-Frequency and Impulsive Base Disturbances

Abstract

This article proposes a transmission-force controllable actuator (TFCA) for vibration suppression in linear motion platforms. Unlike conventional screw-driven systems, the nut-driven TFCA integrates a compliant spring and encoder to measure and control the transmission force in real time, thereby reducing reflected inertia, increasing stiffness, and enabling rapid response to external disturbances. Dynamic models were derived, and two control strategies-acceleration-based vibration suppression control (AVSC) and transmission-force and ACSC (TAVSC)-were implemented. Experiments using a base-shaker setup evaluated three scenarios: back-drivability, impulse disturbance, and multisine excitation (0.1-100 Hz). Results show that TAVSC reduced acceleration and jerk by over 50% in the time domain and achieved more than 90% suppression in the 0.5-8 Hz band, while AVSC exhibited only marginal improvement. Under multisine excitation, TAVSC maintained more than 5 dB suppression across the spectrum and 86% reduction in the 0.5-8 Hz band. These findings confirm that transmission-force feedback substantially improves vibration suppression against impulsive and low-frequency base disturbances, demonstrating the potential of TFCA for applications such as ambulance stretchers and human-sensitive transport systems.