Train protection systems automation

Limited possibilities of using automation or guarding to block certain actions in certain circumstances, or to take actions over. Examples are interlocks on machines which prevent access when the machine is under power or in motion, or automatic train protection systems which apply the brakes if a frain passes a red signal. The latter example is one which leaves the human in the loop to take the decision, but intervenes in clear emergency situations to cope with human failures. We can contrast this with automatic shutdown systems, which take the decision-making away from fhe person and fake fhem out of the loop. The person then has to intervene if fhe automatic system fails, an almost impossible task if fhis occurs very infrequently (e.g. once every few years) . 

Making the same distinction but with different labels, Dekker (2002) desaibed the old view and new view on human error. In the old view, human error is treated as the cause of most accidents, the systems in which people work are safe, the main threat to system safety is human unreliability, and safety progress is achieved by protecting systems from human unreliability through automation, training, discipline, selection, and proceduralization. In the new view, however, human error is treated as a symptom of problems within the system, safety is not inherent within systems, and human error is linked to the tools used, tasks performed, and operating environment. A brief description of the person approach (or old view) and the systems approach (or new view) is presented below. 

The PROTECT architecture consists of sensors deployed in various subway stations, complemented by closed-circuit television (CCTV) cameras that have automated and manual pan-tilt-zoom capabilities. These sensor and camera combinations provide data continuously to a centralized chemical-biological emergency management information system (CB-EMIS developed by Argonne National Laboratory) located in a centralized WMATA operations control center. In addition to the sensor and video data from the stations, train operation data and ambient meteorological data are also ported to the CB-EMIS system. Under normal operations, CB-EMIS can provide operator access to the multiple fixed and movable cameras throughout the metro system to assist law enforcement officers or firefighters. It also monitors the status of the sensor systems deployed in the metro. 

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