Assurance technology for coexisting test and operation subsystems and its application to train control system

The conventional ground-based train control on-board computer system for keeping a fixed distance between trains cannot provide high-density train operation. An autonomous decentralized train control on-board computer system is proposed, in which each train has autonomy to detect its position and speed to communicate this information between a train ahead of it and itself and to judge its speed for safety and punctuality. To realize these real-time on-board computers and their network system, train operation cannot be stopped during their step-by-step construction and testing while both conventional and new systems have to coexist. Autonomous on-line expansion and test technology is proposed where each train has autonomy to select and receive data based on its content and to judge its normal or test operation. In the process of replacing the conventional system with the new one, two assurance technologies are proposed, where networks based on content code communication are integrated to coexist with their different data and they are separated but connected through a gateway. These technologies are evaluated with respect to total system operation. These technologies are shown to be effective on an experimental railway, and are now being applied on the Keihin Tohoku Line in the Tokyo metropolitan area.