Logical Support for Bike-Sharing System Design

Abstract

Automated bicycle-sharing systems (bss) are a prominent example of reconfigurable cyber-physical systems for which the locality and connectivity of their elements are central to the way in which they operate. These features motivate us to study bss from the perspective of Actor-Network Theory – a framework for modelling cyber-physical-system protocols in which systems are networks of actors that are no longer limited to programs but can also include humans and physical artefacts. In order to support logical reasoning about information-flow properties that occur in bss, we use a logical framework that we have recently developed for actor networks, which results from a two-stage hybridization process. The first stage corresponds to a logic that captures the locality and connectivity of actors in a given configuration of the network; the second stage corresponds to a logic of possible interactions between actors, which captures the dynamics of the system in terms of network reconfigurations. To illustrate the properties that can be checked using this framework, we provide an actor-network specification of a particular bss, and use a recently developed tool for hybridized logics to highlight and correct an information-flow vulnerability of the system.</p