8. Light section method contact wire wear measurement system for 360 km/h operation

Wear management of contact wires is important in the maintenance of overhead contact lines. Since the conventional inspection method, which converts the sliding surface width to the residual diameter, had the issue of large errors in locations with uneven wear, we proposed a contact wire wear measurement method using the light section method in the year 2019. However, to implement this method on a high-speed train, it was necessary to expand the measurement range and achieve realistic data analysis times.

To solve this problem, we devised a method that synchronizes the capture timings of multiple cameras with the alternating lighting timings of multiple laser light sources. This allows for the measurement of the entire installation range of Shinkansen contact wires while maintaining measurement accuracy (Figure 1). In addition, we developed an algorithm (Figure 2) to select a profile suitable for wear measurement from among several candidate contact wire profiles acquired. Furthermore, we sped up the calculation process of residual diameter by implementing parallel computation. These improvements made it possible to analyze measurement data for one day of driving within 24 hours. These have led to the development of a light section method contact wire wear measurement system capable of measuring contact wire wear at 50 mm intervals from a vehicle running at 360 km/h.

The results of measurement tests on Shinkansen vehicles (Figure 3) have shown that the error compared to manual measurement at approximately 80 locations, including uneven wear, is generally within 0.3 mm both day and night (Figure 4), confirming that the accuracy is sufficient for practical use. This measurement system is expected to improve the reliability of contact wire wear management and reduce the risk of wire breakage.