Prototype security system for Mexico City's Light Train crossings

摘要

Mexico City's Light Train, one of the electrical transportation systems belonging to the government of Mexico City, services 40,000 passengers daily in the southern sector of the city. Along its trajectory, the Train has to go through several crossings in which safety for vehicles and pedestrians is of paramount importance. We have developed a prototype security system for these crossings based on infrared (IR) detection systems and laser barriers. All the subsystems used in the prototype are controlled by a PC/104 CPU board via the serial communications port and an A/D card. An IR transmitter installed in the train constantly sends information to several receivers deployed at different locations within the crossing. Once the train is detected, the computer activates a set of alarms and barriers in a logical sequence in order to clear the crossing for the train. The laser barrier, formed by a set of eight transmitters and receivers located at different heights within the crossing, is activated as well and is used as a means to detect other emergency situations such as vehicles or pedestrians stranded in the crossing. Discrimination between real and false alarm situations is achieved by encoding both the IR transmitters and the laser beams. In this paper we will discuss experimental and field trials of the, prototype system which will be installed in one crossing this year. Once in place, the Light Train of Mexico City will have its first automated crossing.