Assurance evaluation technology of train control system for achieving expansion during operation

The conventional ground-based train control on-board computer system for keeping the fixed distance between the trains cannot satisfy the high density trains operation. The autonomous decentralized train control on-board computer system is proposed, where each train has autonomy to detect its position and its speed and to judge its speed for safety and punctuality. For realizing these real-time on-board computers and their network system, the train operation cannot be stopped during their step-by-step construction and their test while both of the conventional and new systems have to coexist The autonomous on-line expansion and test technology is proposed where each train has autonomy to select and to receive the data based on its content and to judge its normal or test operation. In the process of replacing the conventional system with the new, two assurance technologies, where the networks based on the content code communication are integrated to coexist with their different data and they are separated but connected through the gate way. These technologies are shown to be effective at the experimental railway, and are now being applied at the Keihin Tohaku Line in the Tokyo metropolitan area.