High-Frequency Vibration Control Using PZT Active Damping
To achieve the goal of high precision positioning, the closed-loop control bandwidth has been increased accordingly for effectively suppressing the dominant vibrations through employing dual-stage or multi-stage actuation systems. However, the resonance modes of a flexible structure usually lie in a frequency range beyond the achievable control bandwidth, and these resonances are easily excited by exogenous sources and induce high-frequency structural vibrations. With the increased bandwidth and sometimes with further attenuation in the low-frequency range, these high-frequency vibrations tend to be amplified according to Bode’s integral theorem [1–3]. As a consequence, these high-frequency vibrations will become a significant obstacle to achieving higher positioning accuracy.