###### Abstract  
Recent years have seen outstanding developments in research and technology, highlighting the importance of railway transportation, especially the implementation of high-speed trains, which is becoming more and more challenging. This facilitates extensive research into the science and technology of the electrical interaction between the components of pantograph-catenary systems (PCSs). Problems regarding the PCS can result in infrastructure incidents, potentially stopping train operations. A common cause of failure in electrified railway PCS is a contact wire's zigzag length that exceeds the prescribed technical limit, which can be caused by missing property or faults in the mounting mechanism. This work proposes a video camera-based monitoring technique for zigzag geometry measurement that additionally employs a Global Positioning System (GPS) sensor to detect the current geographical position of the point of zigzag length measurement. There are two proposed techniques for measuring the length of the zigzag based on image processing. In the first technique, using previously recorded data, the images are analyzed in the laboratory, and in the second, the images are analyzed in real time. Based on the results, we suggest a model and prediction of zigzag length employing hybrid deep neural networks. computer vision; image processing; zigzag length computation; railway transportation; power system; pantograph-catenary system Article Real-Time Video Processing for Measuring Zigzag Length of Pantograph-Catenary Systems Based on GPS Correlation  
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EOL malfunction, causing the catenary suspension to 'hang', the contact wire to break, the pantograph to be damaged, and the suspension to continue for hundreds of meters until the train comes to a stop. The issue of contact between the pantograph and chain has been thoroughly investigated in several scientific papers. The research [3] uses a laser rangefinder to measure the realistic catenary geometry deviation in the Norwegian railway network without contact. Multiple geometry deviation samples are created using the Monte Carlo approach integrated into the catenary model. The stochastic analysis shows that the catenary geometry deviation significantly disperses the pantograph-catenary interaction response. A critical cut-off frequency of 1/16 of the dropper interval is recommended to properly understand how catenary geometry variance affects contact force. The tolerable contact loss rate at high frequency should be used to modify the statistical minimum contact force. At 280 km/h, the modified statistical minimum contact force has an 85.58% chance of being negative. The research presented in [4] addresses the pantograph-catenary system's components, including the pantograph, contact wire, and their interaction, highlighting the importance of the pantograph slide in ensuring dependable power transmission under dynamic conditions. The material properties of the pantograph slide and contact wire, such as electrical conductivity and wear resistance, are identified as important elements impacting system performance. Various detection mechanisms important for system reliability are also discussed. The paper concludes with a perspective on the development of ultra-high-speed trains equipped with novel pantograph-catenary systems designed to withstand more difficult operational environments, providing a comprehensive review of the progress, challenges, and future directions in the development of high-speed railway pantograph-catenary systems. The research [5] describes a study conducted to investigate the characteristics of electrical contact between the pantograph and the catenary. The filed application describes the development of a revolutionary pantograph electrical contact test apparatus. The device simulates zigzag movement, vertical vibration, and flexible line contact between the pantograph contact strip and the contact wire.