Abstract
An obstruction-warning signal is an important piece of signalling equipment used at level crossings in Japan. However, it is not possible to check the visibility of such equipment during train operating hours, because this would require service disruption. This paper therefore proposes a method which employs near infrared LEDs, and can check the visibility of obstruction-warning signals during in-service hours. It has been proved that the developed image processing method, using a near infrared camera and a pan-tilt camera by feedback control installed on a vehicle, can correctly detect specific signal blinking. The paper then gives results from functional field tests.
