Restructuring of Train Control System by Hierarchical Design

Abstract

With regard to the system structure of the train control, conventional systems have had the horizontal independent structure because an individual piece of equipment, such as an ATC (Automatic Train Control) equipment, an electronic interlocking equipment and a facility monitoring equipment, has been separately developed and introduced into systems. In contrast, the concept of our unified train control system is vertical and hierarchically structured. It consists of a “logic layer”, a “network layer” and a “terminal layer”. This vertical hierarchical structure is intended to make systems lean and simple by bringing corresponding segments of the pieces together into each layer and to allow the evolution of systems by accommodating train operator's needs more flexibly. The logic layer consolidates functions of individual pieces of conventional equipment and manages a whole system centrally. The network layer provides standard network interfaces by means of the IP networking without making users conscious of the existence of a network. The terminal layer facilitates reducing, adding and removing local facilities in an effort to downsize them.