Real-Time Systems

according to DIN 44300, the following definition applies to term "real-time system": An operation of a computing system in which programs for the processing of accumulating data are always operational, such that the processing results are available within a predetermined period of time. depending on the application, the data may be generated randomly or at predetermined times. This means that a real-time system must guarantee both the functional correctness and the duration of the determination of the results (temporal correctness). Here, a distinction must be made between hard and soft real-time. For example, a video conferencing system that captures, sends, and displays video and audio within milliseconds only needs to meet soft real-time requirements because delaying a few pictures merely results in a "jerky" display. In contrast, the engine control of a car must meet hard real-time, as improper compliance will result in mechanical damage or, in the worst case, an accident.

The lecture "Realtime Systems" introduces general fundamentals of realtime systems. Among other things, hardware requirements (such as interrupt technology, timers) and real-time operating systems, in particular scheduling techniques such as Rate Monotonic Scheduling or Earliest Deadline First, priority inversion or priority increase are discussed. Finally, the lecture covers various software requirements and programming languages, design methodologies (eg, Finite State Machines, Petri Nets), and performance assessment.

The aim of the exercise is that the participants can independently solve real-time tasks. Practical computing exercises with QNX, a microkernel (Neutrino), real-time operating system (RTOS) and development environment (Momentics) therefore occupy a large space.

The emphasis of the exercise is on thread synchronization and different scheduling algorithms.

• Contact persons for the lecture are Prof. Dr. med. Bernhard Sick and Dipl.-Inf. Tobias Reitmaier.
• Links to the online learning modules "Real-time Systems without critical sections", "Real-time Systems with critical sections" and "Real-time communication".
• Formal, General Information about the lecture (eg assignment to Areas of application, credits, examination type) can be found in the module handbook.
  Degree Program -> Examination Regulations -> Module
• Up-to-date information about the current lecture (eg slides, bibliographical references, examination Dates) will be provided in the Moodle of the University of Kassel.
• Link to the course catalog.