Dynamic target template matching for railway catenary suspension motion detection in wind area

Abstract

A dynamic target template matching method was proposed to identify railway catenary suspension movements of wind-induced vibration in wind area. Catenary positioning point was taken as the target template, which was compared with equal-sized image sequentially using the proposed matching difference. And, three-dimensional contour map of matching difference value at each sub-area was obtained, where the target pixel coordinates were determined by the minimum matching difference value. Considering the complex imaging condition, the target template was updated by the detected target image to sense the gradual change of illumination conditions like brightness and contrast. Furthermore, to eliminate detecting errors due to wind-induced camera vibration, both static and moving target templates were identified for acquiring the absolute motion of the moving target. Finally, validation test was performed with animation in PowerPoint. The calculated target displacement agrees well with theoretical motion with maximum relative error of 1.8%. And experiment application was conducted at site by analyzing the relationship between detecting displacement and wind speed. Results indicate that the proposed dynamic target template matching method can meet required engineering precision and provide an effective way for wind-vibration safety research of railway catenary system in wind area.

Influence of height of earth embankment type windbreak wall on flow field characteristics and catenary wind-induced displacement

“…The trends of the curves, which indicated the amount of lateral and vertical windinduced displacement under the action of a crosswind both gradually decreased to nearly zero, especially of lateral direction that sharply decreased from 143.62 mm at original type to 0.47 mm at h = 1 m, a decrease of 99.67%. Since the special connection and low rigidity, the catenary system is a wind-sensitive structure, and windinduced displacement increased may cause the strong fluctuation in contact force as well as the increased occurrence of contact loss that subsequently leads to a significant deterioration of the pantograph-catenary current collection (Pombo et al, 2009;Pombo & Ambrósio, 2013;Song et al, 2016Song et al, , 2017Zhou et al, 2018). After the windshield is increased to 1 m giving a smaller value of wind speed and corresponding wind load, it can be effectively ensure the wind-induced displacement within a smaller range.…”

Non-contact detection method for pantograph-catenary contact force based on image processing

“…Differential pre-processing, target detection, feature description, and target localization of the images were performed to realize non-contact measurement of geometric parameters of the catenary. Zhou et al 17 used a dynamic template matching method and proposed a matching differential threshold strategy to solve the template matching requirements in different contexts. The technique achieves the identification of catenary support points under crosswind action.…”

Novel Vision Monitoring Method Based on Multi Light Points for Space-Time Analysis of Overhead Contact Line Displacements

“…Various diagnostic and monitoring systems are developed to keep OCL in proper technical condition during operation [ 7 , 8 , 9 , 10 , 11 ]. The search for reliable, safe, inexpensive, and precise measuring and monitoring methods is still ongoing [ 12 , 13 , 14 , 15 , 16 , 17 , 18 ].…”