Stud.IP Uni Oldenburg
University of Oldenburg
30.09.2022 17:09:09
inf456 - Real-Time Systems (Complete module description)
Original version English PDF Download
Module label Real-Time Systems
Modulkürzel inf456
Credit points 6.0 KP
Workload 180 h
Institute directory Department of Computing Science
Verwendbarkeit des Moduls
  • Master's Programme Computing Science (Master) > Theoretische Informatik
  • Master's Programme Engineering of Socio-Technical Systems (Master) > Embedded Brain Computer Interaction
  • Master's Programme Engineering of Socio-Technical Systems (Master) > Systems Engineering
Zuständige Personen
Lehrenden, Die im Modul (Prüfungsberechtigt)
Olderog, Ernst-Rüdiger (Module responsibility)
Skills to be acquired in this module
Introduction to formal methods of the specification and verification of time sensitive systems and their combinations.

Professional competence
The students:
  • Learn about different models of time and real-time properties
  • Specify and verify real-time systems
  • Model real-time systems using Timed Automata and PLC-Automata
  • Apply the model checker UPPAAL for the verification of real-time properties
  • Specify real-time systems using the Duration Calculus
  • Learn about decidability and undecidability results for real-time systems

Methodological competence
The students:
  • Recognize logic and automata as adequate forms for describing real-time systems

Social competence
The students:
  • Work together in small groups to solve problems
  • Present their solutions to groups of other students 

The students:
  • Learn persistence in pursuing difficult tasks
  • Learn precision in specifying problems
Module contents
Examples of time-critical systems are railway control systems, robots, or even gas burners. It is essential for these systems to comply with certain timing conditions. For example, the control of a railway crossing must close the gates not later than 4 seconds after the sensors have reported an approaching train. If the gates are open, they should stay that way for at least 15 seconds to allow for a safe crossing of vehicles.
Different specification methods have been developed to describe such timing conditions.

The Duration Calculus developed by Zhou Chaochen in 1991 is one attractive method. It is a logic combined with a calculus, in which the duration of states can be described. The course will introduce the Duration Calculus and will explain its application by means of examples. As further specification method Timed Automata introduced by Alur & Dill in 1994 will be presented. After the specification of real-time system requirements the verification of programs implementing these requirements will follow. The specification methods of the Duration Calculus and Timed Automata are used to describe the real-time behaviour of these programs. The correctness is then proven on the basis of these behavioral descriptions.

  • discrete and continuous model of time
  • logics and automata models for the specification of real-time systems (predicate logic, Duration Calculus, Timed CTL, Timed Automata, PLC-Automata)
  • decidability and undecidability results for real-time systems
  • model checker UPPAAL for Timed Automata
  • formal specification of real-time systems using Duration Calculus as well as Timed Automata and PLC-Automata
  • verification of concrete Timed Automata using the model checker UPPAAL,
  • transformation of Duration Calculus for discrete time into regular languages
  • implementability of real-time systems on PLC-like hardware
  • E.-R. Olderog, H. Dierks: Real-Time Systems: Formal Specification and Automatic Verification, Cambridge University Press, 2008

Languages of instruction German, English
Duration (semesters) 1 Semester
Module frequency irregulary
Module capacity unlimited
Modullevel / module level AS (Akzentsetzung / Accentuation)
Modulart / typ of module
Lehr-/Lernform / Teaching/Learning method V+Ü
Vorkenntnisse / Previous knowledge Theoretische Informatik I + II
Form of instruction Comment SWS Frequency Workload of compulsory attendance
Lecture 3 SoSe oder WiSe 42
Exercises 1 SoSe oder WiSe 14
Präsenzzeit Modul insgesamt 56 h
Examination Prüfungszeiten Type of examination
Final exam of module
At the end of the lecture period
Exercises and written or oral exam