Abstract:
Vibration sensors find use in monitoring and measuring vibrations of buildings, bridges and in seismological sciences. Geophones are one of the commonly used sensors for ...Show MoreMetadata
Abstract:
Vibration sensors find use in monitoring and measuring vibrations of buildings, bridges and in seismological sciences. Geophones are one of the commonly used sensors for such applications. However, geophones have a natural frequency response like that of a high-pass filter. In the past, several innovations have been introduced to extend the −3 dB corner frequency of the geophone to capture the natural frequencies of a building around 1 Hz. These involved modifying the physical construction of the geophone, and/or introducing digital signal conditioning which is cost intensive. We investigated several analog circuit techniques such that the overall electrical response of the geophone approximates to a low-pass filter response. In one approach the device is followed by a cascade of an ideal integrator and a lossy integrator. This eliminates the zeros of the device while preserving the natural low-frequency pole of the device. It is desirable to create a low-frequency pole independent of the natural pole of the geophone. In order to achieve this goal we used multi-loop feedback method which affords to a low-pass characteristic where the pole frequency becomes different from the natural pole frequency of the geophone. In the following theoretical foundations for two techniques are presented. Validity of the multi-loop feedback technique has been established by numerical simulations and verified by lab-bench experiments.
Date of Conference: 12-14 October 2020
Date Added to IEEE Xplore: 28 September 2020
Print ISBN:978-1-7281-3320-1
Print ISSN: 2158-1525