•A homemade interferometric uniaxial inertial sensor is developed.•Tilt-vertical coupling of the sensor is studied.•The potential for active seismic isolation is experimentally examined.
The goal of ...this study is to demonstrate the capability to actively isolate a platform from seismic vibrations using an interferometric inertial sensor. To this purpose, a homemade high-resolution interferometric uni-axial inertial sensor (in the vertical direction) is developed and then integrated to a single-degree-of-freedom (SDOF) seismic isolation system. A theoretical study is firstly performed in order to better understand the dynamics of the system. It is found that the sensor suffers from a tilt-vertical coupling due to the influence of the gravity force if the sensor is not perfectly aligned. By taking this tilt coupling into account, a dedicated controller is designed, seeking a large vibration isolation in the frequency band of interest. Experiments are then conducted for validating the theoretical analysis and examining the vibration isolation performance. It shows a reduction of the transmitted motion of up to 60 dB in a frequency range from 0.1 Hz to 10 Hz.
In order to operate properly, some precision applications need to be isolated from the ground motion in the six degrees of freedom. This paper presents the model of a hexagonal payload which is ...isolated in all directions. The model is validated by comparison with experimental data. It reproduces properly the suspension modes and the flexibilities of the structure. Two multi-input multi-output (MIMO) control techniques have been applied to this system: centralized control and singular value decomposition (SVD). Both methods allow to reduce by a factor 100 the transmission of ground motion at low frequency (up to 5 Hz) without interfering with the flexible modes.
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