Pantograph Defect Detection (Funded 2012-2013)

Işık University Scientific Research Project 12A301.

A pantograph is a mechanical device that provides continous physical contact with the catenary wires over a locomotive. Catenary wires are suspended at a fixed height. The pantograph is under very high potential of alternating current, generally around 25k Volts. Any imperfections in the catenary wiring or the pantograph itself can result in catastrophic breakdowns.

There are a couple of important defects that can be detected through computer vision on pantographs:

1. When the ground is not level or the catenary wiring is not suspended at a fixed height, arcs occur between the wire and the pantograph. These arc are hazardous for the catenary wiring and must be avoided.

2. The catenary wiring must oscillate between the two extremeties of the pantograph otherwise uneven wear occurs.

3. The catenary wiring must not oscillate beyond the two extremeties of the pantograph otherwise the pantograph and the catenary wiring may break down.

4. The carbon plate on the pantograph is the main conductor of the electricity. This plate must not get any thinner than 5 mm.

5. Any cracks on the carbon plate will result in wear in the catenary wiring. Cracked carbon plates must be immediately detected and replaced.

When pantograph-catenary wiring operation fails, the results are catastrophic. Such a damage requires the replacement of the catenary wiring of the entire section. This means all trains on that route will be down until the replacement is complete.

We design algorithms that detect arcs, excessive oscillations of the catenary wires and uneven wear and cracks of the carbon plate. Our current software runs in real time (40 fps and higher) and stamps the detected alert with time and GPS coordinates. We are currently in the stage of testing our algorithm on the Haydarpaşa-Pendik route.

Below are a couple of snapshots from PILAB pantograph defect detection software. Please click to enlarge.