Formal Modeling and Analysis for Interactive Hybrid Systems

Abstract

An effective strategy for discovering certain kinds of automation
surprise and other problems in interactive systems is to build models
of the participating (automated and human) agents and then explore all
reachable states of the composed system looking for divergences
between mental states and those of the automation. Various kinds of
model checking provide ways to automate this approach when the agents
can be modeled as discrete automata. But when some of the agents are
continuous dynamical systems (e.g., airplanes), the composed model is
a hybrid (i.e., mixed continuous and discrete) system and these are
notoriously hard to analyze.

We describe an approach for very abstract modeling of hybrid systems
using relational approximations and their automated analysis using
infinite bounded model checking supported by an SMT solver. When
counterexamples are found, we describe how additional constraints can
be supplied to direct counterexamples toward plausible scenarios that
can be confirmed in high-fidelity simulation. The approach is
illustrated though application to a known (and now corrected)
human-automation interaction problem in Airbus aircraft.