Software reconstruction and module management for distributed processing of train control

Decentralized train control is ideal in that by distributing computation load over multiple cars, it allows extensibility to, for example, newly installed modules. Besides, compared to centralized control, the delay occurring in cooperative control over multiple devices can be significantly reduced. A technical challenge here is that the legacy software program has a monolithic structure and thus is not amenable to distributed execution. In this paper we present our attempt to tackle this challenge. In the attempt we proceed in two steps. First, we perform a reconstruction of the architecture of the control software. Specifically we decompose the existing software system into several modules that perform independent functions. Second, we devise a mechanism that can manage distributed execution of these modules. A timeliness analysis shows that the new architecture can accommodate addition of new features that the existing architecture could not perform without violating real-time deadlines.