Innovative design of bidirectional piezoelectric actuator for spacecraft micro-vibration isolation based on simulation and experiment

Spaceborne optical payloads require isolation from reaction wheels and other onboard micro-vibration sources that degrade pointing stability. To address this, we propose a novel bidirectional piezoelectric actuator (BPA) capable of symmetric push–pull motion without preload, achieved by integrating a pair of positive and negative Poisson’s ratio flexure amplifiers in series. This new actuator is integrated into a support leg with dual-spiral flexure springs to provide passive vibration isolation, while an advanced control scheme actively suppresses residual micro-vibrations. A hybrid control strategy, blending a fuzzy proportional-derivative controller with an adaptive feedforward filtered-x least-mean-squares algorithm, is implemented to cancel disturbances across a broad frequency range. Finite element simulations and experimental tests demonstrate that the bidirectional actuator delivers a fourfold stroke amplification to provide a displacement exceeding 132 μm. Compared to the system without active control, the isolation system with the hybrid control achieves over 98% amplitude reduction at the modal frequency, and the root mean square reduction reaches 86.51% under 0–20 Hz random micro-vibrations. The results confirm that the BPA and hybrid control strategy effectively maintain a stable and precise isolation platform for spacecraft instruments.