US Patent 7328871 Railroad car coupler gap analyzer

In trains a dragging air hose can snag an object on the tracks and break. A broken air hose can lead to an emergency stop or an accident caused by faulty brakes. The present invention mounts a video camera opposite a lit screen, thereby contrasting the air hose profile against a white screen in all weather and lighting conditions. Machine vision algorithms locate the air hose in a captured image from a moving train, and compute its lowest point. An alarm condition is sent to a remote location. An optional car gap detector is laser based. It helps align the car gap with the data capture for the camera. Another subsystem can include a car coupler height detection algorithm.