| 摘要 |
PROBLEM TO BE SOLVED: To suppress the effects of traveling road surface conditions and detect a vehicle speed stably with high accuracy using a plurality of speed detection means, installed at the bottom of a vehicle running down a track, which detects vehicle speed information on the basis of a reflection wave such as a radio wave radiated upon a track.SOLUTION: According to the present invention, a vehicle has a milliwave sensor for detecting vehicle speed information by the reflected wave of a milliwave radiated upon a track, two milliwave sensors being fixed at the bottom of the vehicle above a rail and at the bottom of the vehicle above another portion of the track other than the rail within a range in which it is possible to receive a reflected milliwave. The vehicle speed information detected by two sensors are compared, and when one milliwave sensor cannot detect a reflected wave or when acceleration or deceleration obtained on the basis of a speed difference calculated from the speed information detected in succession at some point of time or immediately thereafter deviates from vehicle performance, the reflected wave of the other sensor is selected.SELECTED DRAWING: Figure 1 |
