Fiber optical interferometers for vehicle movement monitoring

This article deals with a question of motor-car motion monitoring by the help of fiber optical interferometers. Applied type of the interferometer is Mach- Zehnder interferometer that serves as the basis of mobile device. The interferometer is working at the wavelength 1550 nm during measurement the time changes in interference patterns are evaluated and frequency spectra of particular vehicles are retrieved. It will be presented the ability of the device to distinguish partly individual groups of vehicles (trucks, personals, commercial cars, buses, etc.) but also capability of finer differentiation among personal cars (Skoda Fabia, Skoda Fabia combi, Mazda 6, etc.) but also individual cars of the same brand and type. The total frequency range of this system will be described together with numbers of characteristic frequencies describing particular vehicles and total number of distinguishable cars. System is extendible to speed measurement of the cars motion and the research work upon dynamic weighting is in progress nowadays. At present the patent proceeding is running for device protection.