Applicability to railway sites of train internal environmental monitoring system based on internet of things

Noise in railway vehicles may be caused by various reasons such as friction between the wheel and the rail, contact between the pantograph and the catenary, among other reasons. Of these, friction noise is generated in a metro train due to several curvatures along in the line; this makes passengers uncomfortable during their trip. For this reason, to evaluate the internal noise of railway cars in metro trains from railway technical specifications, a portable sound-level meter has been generally used by an inspector manually. However, there are difficulties on constructing an automated noise evaluation system because conventional sound-level meters cannot provide wireless communication for data transmission to a server in a remote area. Therefore, in this study, an IoT-based remote monitoring system is developed to monitor the internal environments of railway cars in real time. Changes in noise and temperature in a railway car are measured using the system for an entire section of commercial metro line 1 in Daejeon. The test results confirm that changes in noise and temperature can be successfully measured and transmitted to a data server for all sections along the route using the system. The analyzed results for equivalent-sound-levels can be accessed using the dedicated website and the mobile application in a remote area. In future, it is expected that this system can be utilized as an automated monitoring system for the internal environments such as a noise, temperature, dust and carbon dioxide concentration in railway cars by substituting conventional methodology when applied to a commercial metro line