| 摘要 |
<p>PROBLEM TO BE SOLVED: To easily and accurately measure a length of a vehicle without preventing the vehicle from advancing by leading an access of the vehicle in a curved state, oppositely placing range finders as starting and terminal points of the curve, and respectively measuring without contact distances to a tip and to a rear end of the vehicle when it passes through the curve. SOLUTION: A curve is provided on a side wall 2 of an access of a vehicle 1, and range finders 3a, 3b using light or ultrasonic waves are placed with their measuring directions facing on a wall in a front and a rear when the vehicle passes through the curve. In addition a vehicle sensor 4 for sensing that the vehicle 1 is at an appropriate position for measurement is placed. From an installation distance of the range finders 3a, 3b, a distance to the tip of the vehicle and a distance to the rear of the vehicle, which are measured with output timing of a vehicle sensing signal by the sensor 4 are subtracted to obtain a length of the vehicle. Thus measurement is done where the vehicle has turned in the curve, thereby allowing the range finders to be installed without preventing advance of the vehicle for improved measurement accuracy.</p> |
