Technical Analysis of Transition Switching Engineering in Urban Rail Transit Signaling System Upgrades

［Objective］ As urban rail transit lines in many major cities across China have entered the system upgrade stage, it is crucial to ensure the safety, reliability, and efficiency of transition switching engineering during the upgrade process, which will minimize the impact of modifications while maintaining operational continuity. Therefore, an in-depth analysis is conducted on the key technologies for transition switching during signaling system upgrades. ［Method］ Based on the signaling system upgrade project of Guangzhou Metro Line 1 (hereinafter referred to as ′Line 1′), the professional technology of signaling system engineering is combined with theoretical and technical analysis methods. The engineering technologies related to system switching based on transitional switching devices are investigated. In the research process, all potential scenarios requiring transition switching during signaling system upgrades are systematically broken down, with detailed refinements made to the design schemes of switching circuits and their implementation plans. Additionally, the technical specifications for switching devices are further analyzed. ［Result & Conclusion］ Based on the implementation data and experience from Line 1 upgrade project, a set of transition switching scenarios for various signaling system upgrade technologies is successfully developed, including typical switching circuits for both trackside and onboard systems. Furthermore, the main technical requirements for transitional switching devices are proposed, along with specification parameters and architectural design for trackside and onboard transition switching devices.