Microvibration control platform for high technology facilities subject to traffic-induced ground motion

This paper investigates the possibility of using a microvibration control platform to isolate a batch of high tech equipment from the floor of a building subject to nearby traffic-induced ground motion. The governing equation of motion of the coupled platform-building system is derived in the absolute coordinate to facilitate the feedback control and performance evaluation of the platform based on the BBN vibration criteria with the absolute velocity being targeted. A hybrid control system composed of passive mounts and active hydraulic actuators with a sub-optimal control algorithm is designed to actively control the platform. Hydraulic actuator dynamics are also considered in the modelling of the control system to avoid possible instability of the platform. The performance of actively controlled platform is assessed through comparisons with the cases of the building without control, the building with passively controlled platform, and the building with passive base isolator. Simulation results indicate that passively controlled platform and passive base isolator can be effective in reducing microvibration of high tech equipment if their parameters are properly selected. The actively controlled platform is superior to the passively controlled platform and passive base isolator because of its high performance and robustness.