Automatic Train Protection (ATC)Speed Limit是什么意思

用法例句

And it is composed of three subsystems: automatic train protection, automatic train operation and automatic train supervisory.

该系统由 3个子系统构成 :列车自动保护系统 ( ATP) ,列车自动运行系统 ( ATO) ,列车自动监控系统( ATS) 。