Reliability improvement of obstacle detection in an IR barrier

This work proposes several techniques to validate the detection of objects in railway environments. The system for obstacle detection is based on an infrared emitting barrier and another of receivers placed on opposing side in the railway, establishing different optical links between them. The system is located at the segments of the railroads where it is desired to know the existence of objects, so the rail circulation becomes safe. The interruption of one or several links in the sensorial system should produce an alarm. Since the detection is based on the radiation lack in the detectors, the degradation of the optical link can occur due to the atmospheric attenuation, or the solar radiation, so even without existing objects, radiation is not received. Because of that, it is necessary the dynamic adaptation of the detection threshold, so the system is adapted to the degradation of the optical channel. Since the minimum size of the object generating alarm is constrained at 50×50×50cm, some situations can interrupt several links but alarms should not be generated. Typical cases are the flight of leaves or the movement of small animals in the scanned area. Since the interruption of the links is the necessary condition, but not sufficient, for the existence of an object, this work proposes the combined use of diverse techniques to validate the existence of objects, and it provides a high reliability to the detection system.