556 research outputs found
Formalization and Validation of Safety-Critical Requirements
The validation of requirements is a fundamental step in the development
process of safety-critical systems. In safety critical applications such as
aerospace, avionics and railways, the use of formal methods is of paramount
importance both for requirements and for design validation. Nevertheless, while
for the verification of the design, many formal techniques have been conceived
and applied, the research on formal methods for requirements validation is not
yet mature. The main obstacles are that, on the one hand, the correctness of
requirements is not formally defined; on the other hand that the formalization
and the validation of the requirements usually demands a strong involvement of
domain experts. We report on a methodology and a series of techniques that we
developed for the formalization and validation of high-level requirements for
safety-critical applications. The main ingredients are a very expressive formal
language and automatic satisfiability procedures. The language combines
first-order, temporal, and hybrid logic. The satisfiability procedures are
based on model checking and satisfiability modulo theory. We applied this
technology within an industrial project to the validation of railways
requirements
Preparation and control of intelligent automation systems
In the automation systems of tomorrow, it is likely that the devices included have various degrees of autonomy, and include advanced algorithms for perception and control. Human operators will be expected to work together with collaborative robots as well as with roaming robots for material handling.The volatile nature of the environment of such intelligent automation systems lead to an enormous amount of possible situations that can arise and which need to be suitably handled. This complexity makes development of control systems for intelligent automation systems difficult using traditional methods.As an alternative, this thesis presents a model-based control framework, which uses a combination of formal specification and automated planning. The proposed framework allows for defining the intentions of the automation system on a high level, which enables decisions that influence when things should occur to be modeled using logical constraints, rather than programming. To achieve a modular framework, low level, reusable, resource models are composed by 1) formal specification to ensure safety and 2) applying an abstraction called an operation, which couples the reusable resources to the intentions of the system. By planning also the resources\u27 detailed actions, the operations can, when possible, be completed regardless of the resources\u27 current state. This eases error-recovery, as resources do not have to be reset when an error occurs.Additionally, the thesis proposes an iterative and interactive workflow for integrating the proposed model-based control framework into a virtual preparation process, using computer-based simulation as a tool for validating formal specifications. The control framework allows for adding new constraints to a running system, enabling an efficient and interactive preparation process.The framework has been applied to a use case from final assembly, which features human-robot collaboration. Experimental results on the ability to handle unforeseen errors and planning performance are presented
A Review of Formal Methods applied to Machine Learning
We review state-of-the-art formal methods applied to the emerging field of
the verification of machine learning systems. Formal methods can provide
rigorous correctness guarantees on hardware and software systems. Thanks to the
availability of mature tools, their use is well established in the industry,
and in particular to check safety-critical applications as they undergo a
stringent certification process. As machine learning is becoming more popular,
machine-learned components are now considered for inclusion in critical
systems. This raises the question of their safety and their verification. Yet,
established formal methods are limited to classic, i.e. non machine-learned
software. Applying formal methods to verify systems that include machine
learning has only been considered recently and poses novel challenges in
soundness, precision, and scalability.
We first recall established formal methods and their current use in an
exemplar safety-critical field, avionic software, with a focus on abstract
interpretation based techniques as they provide a high level of scalability.
This provides a golden standard and sets high expectations for machine learning
verification. We then provide a comprehensive and detailed review of the formal
methods developed so far for machine learning, highlighting their strengths and
limitations. The large majority of them verify trained neural networks and
employ either SMT, optimization, or abstract interpretation techniques. We also
discuss methods for support vector machines and decision tree ensembles, as
well as methods targeting training and data preparation, which are critical but
often neglected aspects of machine learning. Finally, we offer perspectives for
future research directions towards the formal verification of machine learning
systems
Visual counterexample explanation for model checking with Oeritte
Despite being one of the most reliable approaches for ensuring system
correctness, model checking requires auxiliary tools to fully avail. In this
work, we tackle the issue of its results being hard to interpret and present
Oeritte, a tool for automatic visual counterexample explanation for function
block diagrams. To learn what went wrong, the user can inspect a parse tree of
the violated LTL formula and a table view of a counterexample, where important
variables are highlighted. Then, on the function block diagram of the system
under verification, they can receive a visualization of causality relationships
between the calculated values of interest and intermediate results or inputs of
the function block diagram. Thus, Oeritte serves to decrease formal model and
specification debugging efforts along with making model checking more
utilizable for complex industrial systems.Comment: The 25th International Conference on Engineering of Complex Computer
Systems (ICECCS 2020
Methoden und Beschreibungssprachen zur Modellierung und Verifikation vonSchaltungen und Systemen: MBMV 2015 - Tagungsband, Chemnitz, 03. - 04. MĂ€rz 2015
Der Workshop Methoden und Beschreibungssprachen zur Modellierung und Verifikation von Schaltungen und Systemen (MBMV 2015) findet nun schon zum 18. mal statt. Ausrichter sind in diesem Jahr die Professur Schaltkreis- und Systementwurf der Technischen UniversitÀt Chemnitz und das Steinbeis-Forschungszentrum Systementwurf und Test.
Der Workshop hat es sich zum Ziel gesetzt, neueste Trends, Ergebnisse und aktuelle Probleme auf dem Gebiet der Methoden zur Modellierung und Verifikation sowie der Beschreibungssprachen digitaler, analoger und Mixed-Signal-Schaltungen zu diskutieren. Er soll somit ein Forum zum Ideenaustausch sein.
Weiterhin bietet der Workshop eine Plattform fĂŒr den Austausch zwischen Forschung und Industrie sowie zur Pflege bestehender und zur KnĂŒpfung neuer Kontakte. Jungen Wissenschaftlern erlaubt er, ihre Ideen und AnsĂ€tze einem breiten Publikum aus Wissenschaft und Wirtschaft zu prĂ€sentieren und im Rahmen der Veranstaltung auch fundiert zu diskutieren. Sein langjĂ€hriges Bestehen hat ihn zu einer festen GröĂe in vielen Veranstaltungskalendern gemacht. Traditionell sind auch die Treffen der ITGFachgruppen an den Workshop angegliedert.
In diesem Jahr nutzen zwei im Rahmen der InnoProfile-Transfer-Initiative durch das Bundesministerium fĂŒr Bildung und Forschung geförderte Projekte den Workshop, um in zwei eigenen Tracks ihre Forschungsergebnisse einem breiten Publikum zu prĂ€sentieren. Vertreter der Projekte Generische Plattform fĂŒr SystemzuverlĂ€ssigkeit und Verifikation (GPZV) und GINKO - Generische Infrastruktur zur nahtlosen energetischen Kopplung von Elektrofahrzeugen stellen Teile ihrer gegenwĂ€rtigen Arbeiten vor. Dies bereichert denWorkshop durch zusĂ€tzliche Themenschwerpunkte und bietet eine wertvolle ErgĂ€nzung zu den BeitrĂ€gen der Autoren. [... aus dem Vorwort
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