Dynamic modelling of an electro-hydraulic actuator to isolate machine tools from ground vibrations

This paper presents the dynamic modelling of a novel electro-hydraulic actuator that decouples, attenuates and isolates ground motion to keep dynamic excitations transmitted to machine tools below permissible levels. Closed-loop dynamics are formulated by considering the hydraulic system dynamics as well as the dynamics of the actuator and machine tool. Controlled closed-loop transmissibility shows the actuator to have excellent attenuation of ground vibrations for excitation frequencies of up to 30 Hz. Numerical investigations representative of typical floor vibration levels experienced by machine tools demonstrate that the device isolates ground motion by up to 80%.