| 摘要 |
PROBLEM TO BE SOLVED: To obtain a highly accurate train location detection device that can be realized as a radio system. SOLUTION: Ground radio units 21 through 23 count the processing time from when they finish receiving a call signal sent out from an onboard radio unit 12 until they emit a response signal, and emit a response signal including processing time data and an identification number data previously given to each device. The onboard radio unit 12 of an onboard device 1 emits a call signal to the ground radio unit 21, counts the response time from when it finishes emitting the call signal to when it receives a response signal sent out from the ground radio unit, calculates a propagation delay time based on the response time and processing time included in the response signal, and detects the location of a corresponding train according to the propagation delay time and the identification number of the ground radio unit 21. |
