Continuous-Time Models for System Design and Analysis

Abstract

We illustrate the ingredients of the state-of-the-art of modelbased approach for the formal design and verification of cyber-physical systems. To capture the interaction between a discrete controller and its continuously evolving environment, we use the formal models of timed and hybrid automata. We explain the steps of modeling and verification in the tools Uppaal and SpaceEx using a case study based on a dual-chamber implantable pacemaker monitoring a human heart. We show how to design a model as a composition of components, how to construct models at varying levels of detail, how to establish that one model is an abstraction of another, how to specify correctness requirements using temporal logic, and how to verify that a model satisfies a logical requirement.

Methods, Languages and Tools for Future System Development

“…This nicely illustrates the close relationship between checking-based approaches that control whether certain properties are guaranteed or can be satisfied, and methods for property enforcement that aim at synthesizing property conforming solutions. [1] illustrates the ingredients of the state-of-the-art of the model-based approach for the formal design and verification of cyber-physical systems. To capture the interaction between a discrete controller and its continuously evolving environment, formal models of timed and hybrid automata are used.…”

“…Technical progress does not necessarily mean conceptual improvement, as summarized by Dijkstra [9]: "as long as there were no machines, programming was no problem at all; when we had a few weak computers, programming became a mild problem, and now we have gigantic computers, 1 programming has become an equally gigantic problem". This quote from 1972, which expresses Dijkstra's frustration in having to deal with increasingly powerful, but also increasingly difficult-to-handle machinery, embodies an important message to software scientists, the quest for simplicity 2 , a message even more important today.…”

The 10,000 Facets of MDP Model Checking

“…The often excessive size of the state space spanned by a concrete verification problem is a major impediment to practicality across the entire spectrum of verification methods, see e.g. [2,92]. This problem of state-space explosion also affects negatively the basic probabilistic model checking procedures we discussed thus far.…”

Language-Driven Engineering: From General-Purpose to Purpose-Specific Languages

“…8 are well suited to establish domain-specific libraries of (elementary) rules at the what level: the meaning of these BDDs is intuitively clear also for unexperienced users. 15 Once the implementation code for the involved elementary predicates is available, the BDDs shown in Fig. 8 are sufficient to generate fully executable code for the composition of Fig.…”

“…Also the approaches presented in the remaining papers could profit from DSLs, e.g., as follows: [41] for specifying certain assertions or contracts, [43] for specifying data flow analyses 20 , [25] for specifying test models, [42] for defining learning alphabets or representing the learning result, [40] for modularly specifying the required code instrumentation, e.g. in an aspect-oriented fashion, and [15,19,66] for conveniently specifying their enriched system structures. Corresponding mIDEs (could) then guide the development by exploiting the DSL's specifics, e.g., the interpretation of assertions, security predicates, time, or probabilities.…”