Narrow-Band Active Damping Using Higher-Order Band-Pass Control: A Loop-Shaping Perspective

Abstract

Lightly damped structural resonances limit the performance of high-precision mechatronic systems and flexible structures. Conventional active damping schemes, such as positive and negative position feedback, provide moderate damping at the targeted mode but often suffer from spillover at low and high frequencies, especially in systems with closely spaced modes or high noise sensitivity. This paper presents a generalized higher-order bandpass active damping framework that enhances modal selectivity and stability for narrowband damping. Analytical formulations establish relationships between controller order, bandpass slope characteristics, and stability margins, enabling systematic design with high phase robustness. A non-minimum-phase filter is incorporated to compensate for delay-induced phase degradation, while a tunable damping coefficient increases design flexibility. Simulation studies on identified collocated and non-collocated systems demonstrate that the proposed controller achieves sharp resonance suppression, improved noise attenuation, and reduced spillover compared with conventional active damping schemes.