Automated urban train control with hybrid Event-B: ‘Tackling’ the rugby club problem

Abstract

Normally, the passengers on urban rail systems remain fairly stationary, allowing for a relatively straightforward approach to controlling the dynamics of the system, based on the total rest mass of the train and passengers. However, when a mischievous rugby club board an empty train and then run and jump-stop during the braking process, they can disrupt the automatic mechanisms for aligning train and platform doors. This is the Rugby Club Problem for automated urban train control. A simple scenario of this kind is modelled in Hybrid Event-B, and sufficient conditions are derived for the prevention of the overshoot caused by the jump-stop. The challenges of making the model more realistic are discussed, and a strategy for dealing with the Rugby Club Problem, when it cannot be prevented, is contemplated.