24. Automatic Pantograph Drop System Using Real-time Abnormality Detection in the Current Collection System

When abnormalities occur in the pantograph or overhead contact line, they can cause a chain of damage to the overhead lines in a wide area or complete failure of pantographs within a train set, potentially leading to large-scale transportation disorders. Therefore, we developed a system that installs a camera on-board to monitor the current collection system in real time and automatically lowers the pantograph when abnormalities are detected from the images (Figure 1).
Based on records of past large-scale transport disorders, the detection targets were set to pantograph part detachments and foreign objects attached to the overhead contact line.

For detecting pantograph part detachments, we developed a detection algorithm combining object detection AI with coordinate processing. This algorithm also supports detection of step-shaped wear on pantograph contact strips and abnormal arcs. For foreign objects such as plastic sheets or futons attached to the overhead contact line, which are difficult to pre-train on, we developed a detection algorithm that combines AI requiring no training data and a system for abstract specification of detection targets within the overhead contact line area setting. Results from in-house testing confirmed that pantograph part detachments can be detected within one second, and foreign objects can be detected up to 40 meters away from the camera, both with no false positives or missed detections.

This system can prevent a chain of equipment damage caused by the current collection system, which is expected to reduce downtime by ensuring train operability and shortening equipment restoration time.