Progress in Signaling for Track Guided Systems

The advantages of tracked systems over nontracked systems, e.g. the case of automation, are presented. Vehicle detection and communication are critical in automatic systems because of the safety, reliability, and cost factors. Current methods of tracked vehicle detection and communication are reviewed: fixed and moving block systems, the use of crossover wires and the choice of signaling frequencies. The advantages of using high frequencies and surface electromagnetic waves are given and current high frequency methods under investigation are reviewed. Because of the high cost of installing waveguides alongside the track, an innovative method is proposed in which the track is used as a surface waveguide. A block diagram of a headway control and collision avoidance system is illustrated. The results are presented for the analysis of a rail adapted to form a waveguide and these indicate the feasibility of this idea.