Frequency Acquisition Method for Measuring Strain of Vibration Wire Sensor

Abstract

A vibrating wire sensor is designed to monitor structural transformations at construction sites. The sensors that measure pressure and strain at construction sites are ultimately expressed by stress values. To express a stress value, the vibration frequency is measured by attaching a sensor without affecting the structure. Accurate measurement of a vibrating wire sensor is used to measure the resonance frequency of the target structure. The problem is sensor wire response time and noise. For accurate measurement, the problem was solved by using a noise reduction circuit and a method of calculating the time according to the cycle of a microcontroller unit (MCU). To calculate the frequency accurately in the MCU, the time corresponding to one cycle is measured by the clock in the MCU, and time-base sensor wire analysis is conducted. This study proposes a method to accurately measure the resonance frequency.