| 摘要 |
<p>The speed of a train 1 is determined from the output from two vibration sensors 3, 4 at spaced-apart locations a known longitudinal distance d apart inside the same car - or different cars - of the train. The vibration sensors measure vibration during movement of the train; the measured vibration patterns A1, A2 are correlated to identify patterns detected by each sensor relating to a common source; the time difference is determined between measurement of the identified patterns at each sensor; and the time difference is related to the distance between the vibration sensors to determine the speed. The sensors may be located over respective bogies. Weighting may be applied to the sensor outputs. The speed may be combined with an independently determined train speed.</p> |
