Compensation Techniques for Vibration Sensors with Application in Structural Health Monitoring

Abstract

With the prolific usage of vibration analysis to extract information about different structures (buildings and bridges etc.), vibration sensors have become an important device in Structural Health Monitoring (SHM). We tried to modify the sensor systems with a concentration on the analog subsystem sensors. Different types of seismic sensors with different analog characteristics are available to use in vibration sensors. Regarding the analog characteristics, different analog stages are needed to shape the signal appropriately. For the required level of sensitivity in SHM, the optimum choice for our case is a geophone. Mass-spring velocity meters or geophones are available in different sizes and characteristics. The main drawback of the geophones is their high-pass frequency response. As a result, vibrations below a certain frequency which is called corner frequency, is hard to detect. In this study, along with the adequate explanation on the filter and amplifier selection, several analog methods have been proposed to modify the lower frequency response of the geophone. In this chapter, after an introduction to the vibration sensors, we briefly described the geophone. Then we proposed some compensation techniques along with other analog stages. The experimental results verify the correctness of the techniques.