| 摘要 |
A train detection security system and method comprising sensor units (2a, 2b,....) arranged for being fixed to at least one rail (10a, 10b). The sensor units (2a, 2b,....) are arranged for detecting a first signal (s1) induced by a moving train (6). Each sensor unit (2a, 2b....) is divided in at least a first chamber (21) and a second chamber (22), where said first and second chambers (21, 22) are separated by an electromagnetic shield (23). The first chamber (21) comprises a piezoelectric element (24) fixed to an outer wall (25) of said first chamber (21), and an amplifier (26). A warning signal is generated in a control system based on the approaching train. |
