An ARM-based solution for train signal current detection

Train signal machine is the key signal equipment which indicates the train safely operation. To ensure traffic safety, managers have to monitor the current intensity of train signal´s bulbs constantly. This paper presents a new train signal monitoring technology, a loop current collector, which could precisely detect filament´s alternating current effective value. The hardware uses operational amplifier and optocoupler isolation circuit to diminish interference and adjust suitable input signal amplitude. The software uses fuzzy judgments to further avoid clutter errors. Besides, the collector is equipped with a communication module which can send the real-time measurement results to monitoring hosts. The current collector has an ARM processor for sampling and results computing, it achieves a dynamic monitoring of train signal´s loop current and gives an early intelligence warning. The field test result shows that the technology is high reliable and low complex, its detection precision meets the requirements of railway applications.