Robust Fuzzy Control for Intelligent Pneumatic Vibration Isolation

Pneumatic vibration isolation is a critical system for maintaining a clean, micro-vibratory work environment for precision instruments and semiconductor manufacturing. Passive pneumatic isolation cannot meet the demand for low-frequency vibration isolation and even produces resonance phenomenon. In this study, an active pneumatic vibration isolator was developed to suppress the interference of low-frequency vibration using an intelligent control method. Firstly, the working model of linearization at the working point of the system is established. Then, based on the robust H∞ control theory, a controller capable of suppressing low-frequency vibration perturbations with high robustness is designed, and a serial double-loop control method is adopted to realize the vibration isolation effect while increasing the bandwidth of the system. Finally, an excitation signal of 1–10 Hz is applied to test the performance of the pneumatic vibration isolation system in the case of intelligent control and compare it with the passive vibration isolation effect. The experimental results unambiguously demonstrate that the active control method enhances vibration isolation performance in the low-frequency range, effectively mitigating resonance peaks associated with the passive isolator.