Analysis of the use of fiber-optic sensors in the road traffic

摘要

This publication focuses on the use of fiber-optic sensors in the transport applications. Fiber-optic sensors are based on the fiber-optic communications, using nearly identical elements and components as classic fiber-optic communications. The fundamental difference is that in the fiber-optic communications we limit the effects of the environment on the transmission of the information itself, whereas, in the case of fiber-optic sensors, different arrangements are sought to maximize these impacts. In this publication, so-called interferometric sensors are described which work on the basis of comparison of light phases in two parts (the measuring and reference arm). These phase differences can be measured with extreme sensitivity, so fiber-optic interferometers are much more accurate than most other sensors. The base of the structure is an optical fiber, so sensors are immune to electromagnetic interference (EMI) and offer the simplicity of implementation, as the sensors do not require destructive installation on the roads. The publication describes the use of a Mach-Zehnder interferometric sensor type. This type of sensor has been practically validated and discussed for the automotive applications. The primary tracked parameter is the monitoring of the traffic density. The results presented in this publication are based on the evaluation of long-term time series containing hundreds of samples and confirm the idea of using fiber-optic sensors in transport applications.