FPGA-Based Architecture for a Multisensory Barrier to Enhance Railway Safety

Due to the continuous development of the high-speed railway lines and the growth of automatic systems, it is becoming more and more necessary to install safety elements to prevent accidents. One of these elements is the so-called obstacle fall detector on the tracks, in charge of detecting the sudden appearance of dangerous objects in the safety area of the tracks. For that purpose, this paper proposes the design of a multisensory system, consisting of two barriers, one emitting and another receiving, which are placed at opposing sides of the railway tracks, respectively, and they use infrared (IR) and ultrasonic (US) sensors in order to establish optical and acoustic links between them. From the processing point of view, this proposed system can be divided into the low and high levels. Whereas the high-level stage corresponds to the monitoring system, providing information about the state of the tracks (free or occupied by obstacles), the low-level one is responsible for managing emissions and detections carried out by the sensory system. The work presented here is focused on the design and implementation of the low-level stage in a field-programmable gate array device, based on the encoding of the sensory signals for both the US and the IR one. The experimental results have successfully validated the feasibility of the proposal, providing a high reliability to the detection system.