Position detector for track mounted surveillance systems

摘要

A mechanism for detecting the position of a carriage moveable along a track. The mechanism includes a wheel fixed to the carriage which rotates as the carriage moves along the track. A mark is disposed on a portion of the wheel. A detector is fixed to the carriage for sensing the mark as the wheel rotates and outputs a signal in response. A carriage processor receives the signal and determines the position of the carriage along the track.