Feedforward compensation in vibration isolation system subject to base disturbance

Skyhook technology is widely used in vibration control. However, it only attenuates vibration near the resonant frequency. To enhance the control performance of an isolation system, a new feedforward compensation control strategy, achieved by measuring base velocity with a geophone, is proposed in this paper. Firstly, the mathematical model of single degree-of-freedom pneumatic spring is derived in detail. Secondly, the feedback controller is designed experimentally, and an anti-windup proportion-integral controller is used. Thirdly, the feedforward compensation controller is designed using a finite impulse response filter, whose coefficients are updated on-line using the filtered-x least-mean-square algorithm with improved gradient estimate. At last, a series of experiments were conducted, and the velocity attenuation rate is calculated. The results of these experiments prove that the proposed method can greatly reduce base disturbance, and keep a high vibration velocity attenuation rate at all frequency points.