High-frequency inertial control approach for ultra-precision machine dynamic stiffness enhancement

Vibration control remains challenging in ultra-precision machine tools, where compact architectures and stringent motion-accuracy requirements limit conventional damping solutions. Beyond conventional energy-dissipative damping methods, this paper proposes a high-frequency inertial control approach that applies controlled harmonic excitation directly to the stage carriage. As inertial effects become dominant, the resulting inertial interaction increases effective dynamic stiffness, reduces structural receptance, and suppresses vibration. We systematically model actuation-induced disturbances at the pressurised air film interface to capture the coupled dynamics while preserving motion accuracy. Model-guided design identifies an optimal actuator-source dynamic transmission path, yielding near-ideal system behaviour and a consistent reduction in vibration acceleration under near non-dissipative air film conditions. Experimental machining tests show that, at 600 Hz, the proposed approach markedly suppresses machining chatter. Specifically, the surface roughness Sa decreases from 0.298 to 0.224 μm, while cutting-force fluctuations decrease from 8.15 to 5.53 N, accompanied by reduced grain-impact-induced subsurface crack propagation. More broadly, this work establishes high-frequency inertial control as a structurally integrated strategy for regulating machine dynamics, providing a practical route towards vibration-resilient precision machine tools.