Development of Basic System on ATS-X with Continuous Surveillance Pattern

The authors are currently developing a new ATP (Automatic Train Protect) system, known as the ATS (Automatic Train Stop) system in Japan. This new system, named the "ATS-X system", is interoperable with the existing ATS-S system used on almost all Japan Railway companies' narrow-gauge lines. In this ATS-X system, a continuous surveillance pattern is generated in an on-board device using digital data intermittently transmitted from beacons. The safety level of the ATS-X system is therefore higher than that of the ATS-S system. We considered the basic functional specifications of the ATS-X system for practical use with seven JR companies. In this paper, we report on these specifications and the functional test results from the field.