A hybrid-actuated vibration isolator with high stiffness and broadband vibration isolation performance: Design, simulation, and experimental validation

Ultra-precision equipment, such as lithography, inspection, and precision motion platforms, is highly sensitive to environmental vibrations, where even minor disturbances can significantly degrade positioning accuracy and process yield. Under complex operating conditions, such equipment is not only subjected to broadband random vibration excitations from the foundation and external environment, but also required to suppress disturbances induced by internal moving components and load variations. Therefore, how to construct an isolation system that combines broadband vibration isolation performance with high disturbance rejection capability remains an urgent technical challenge. To address this issue, this paper proposes a hybrid-actuated vibration isolator based on a voice coil motor and piezoelectric ceramics. First, a mechanical supporting structure compatible with the physical characteristics of the dual actuators is designed, and its dynamic model is established. Second, a feedforward-feedback control system is developed, and the isolation performance is investigated through simulation analysis. Finally, experimental validations were conducted, and the results demonstrate that the proposed hybrid-actuated isolator achieves vibration attenuation below −20 dB in the frequency range of 6–20 Hz, while providing effective vibration isolation over the target frequency band of 1–100 Hz. By fully exploiting the complementary advantages of the two types of actuators, the proposed isolator significantly improves the inherent limitations of a single actuator in terms of physical characteristics, effectively reduces resonance peaks, enhances low-frequency isolation performance, and further broadens the isolation bandwidth, indicating promising potential for engineering applications.