BigraphTalk: Verified Design of IoT Applications

Abstract

Graphical IoT device management platforms, such as IoTtalk, make it easy to describe interactions between IoT devices. Applications are defined by dragging-and-dropping devices and specifying how they are connected, e.g. a door sensor controlling a light. While this allows simple and rapid development, it remains possible to specify unwanted device configurations -such as using the same device to drive a motor up and down simultaneously, risking damaging the motor.We propose BigraphTalk, a verification framework for IoTtalk that utilizes formal techniques, based on bigraphs, to statically guarantee that unwanted configurations do not arise. In particular, we check for invalid connections between devices, as well as type errors, e.g. passing a float to a boolean switch. To the best of our knowledge, BigraphTalk is the first platform to support the graphical specification of correct-by-design IoT applications.BigraphTalk provides fully automated verification and feedback without end-users ever needing to specify a bigraph. This means any application, specifiable in IoTtalk, is guaranteed, so long as verification succeeds, not to violate the given configuration constraints when deployed; with no extra cost to the user.

Design and Verification of Multi-Agent Systems with the Use of Bigraphs

“…The bigraph theory was published by Robin Milner in 2008 but has already been extended with a notion of overlapping locations [24] and probability [25]. Bigraphs are currently found useful in areas such as system of systems design [26], IoT [27], and wireless network modeling [28]. Currently, there are a few tools that support modeling systems with bigraphs, the most notable of them are Bigraphical Model Checker [29] (discontinued), Bigraph Framework for Java [30], and BigraphER [31].…”

Conditional Bigraphs

“…Bigraphs are a universal mathematical model, introduced by Milner [15], for representing spatial and non-spatial relationships of physical or virtual entities. They have been applied to a wide range of systems including: mixed-reality systems [4], networking [6], Iot [2], security of cyber-physical systems [1], and biology [13].…”

“…Bigraphs are not a full category as composition is not defined for non-disjoint supports. We do not discuss support here 2. The definition of solid for bigraphs with sharing differs slightly, see[17, Defn 3.6.1].…”

Formal Modeling IoT Systems on the Basis of BiAgents* and Maude

“…This allows defining the behavior and the states of a dynamically evolving system as an IoT one. Moreover, Bigraphs have simplicity of understanding that permits interdisciplinary exchange between experts in IoT and in formal methods [4]. An IoT system has also a virtual aspect, an intelligent part that manages the different physical components to ensure an intelligent execution.…”