A radiofrequency sensor for managing the accosting phase between subway cars

摘要

When an automatic subway car is damaged and stopped, it must be accosted by another subway car and pushed to the next station. The approach phase (before accosting) is accomplished at low speed to avoid collision between the two subway cars. Theclassical system used to detect the damaged subway car position is based on cameras. Then the obtained range interval is very small (about 70 m). In this paper we propose a new system based on radio-frequency techniques which allow a large detection range (about 500m) in the tunnel. This system uses pseudo-random sequences combined with correlation receiver. This kind of sensor avoids interferences with other RF waves and improve the subway traffic control. A theoretical analysis of both the proposed RFsystem and the corresponding transponder will be given together with the obtained results.