Adaptive control of a two-stage vibration isolation mount

An adaptive control system has been developed that may be used for active noise and vibration control problems involving one-dimensional propagation. Based on the least-mean-squares (LMS) algorithm, the adaptive controller performs both system identification and control in real time, without the need for a priori measurements of the system. Since the controller is adaptive in nature, it is possible to track changes in the system while maintaining optimal control. In the present application, the adaptive control system was applied to the problem of minimizing the force transmitted through a two-stage vibration isolation mount. The control system was implemented in real time using a Motorola DSP56000ADS signal-processing board and applied on a physical vibration isolation mount. For periodic excitations, the adaptive controller was capable of providing 30to 40-dB attenuation of the transmitted vibration. For broadband excitation, some limitations exist, but the controller was still capable of providing about 20-dB attenuation over the lower frequency range. The controller also demonstrated the ability to track changing system parameters to maintain optimal control of the system.