| Organizer: | Henriksson Dan, Lund University, Sweden |
|---|---|
| Co-Organizer: |
Cervin Anton, Lund University of Technology, Sweden Andersson Martin, Lund University of Technology, Sweden Arzen Karl-Erik, Lund University of Technology, Sweden |
| Topic | 3.1 Computers for Control |
| Chair: | Henriksson Dan, Lund University of Technology, Sweden |
| Date: | 2005-07-03 |
| Time: | 09:00 - 13:00 |
| Room: | University Lecture Room 203b |
| Abstract: | Control systems are becoming increasingly complex from the perspectives of both control and computer science. Today, even seemingly simple embedded control systems often contain a multitasking real-time kernel and support networking. As a result of economic considerations, most embedded control systems are subject to resource constraints, manifesting itself by limited CPU speed, memory, and network bandwidth of the target platform. In addition, a strong trend within industry today is to use commercially available information technology and commercial-off-the-shelf (COTS) components deeper and deeper in the real-time control systems. On the other hand, digital control theory normally assumes equidistant sampling intervals and a negligible or constant control delay between sampling and actuation. However, this can seldom be achieved in practice in a resource-constrained system. The temporal non-determinism introduced by the computer system in the form of delay and jitter can lead to significant performance degradation. To cope with this, the resource constraints of the implementation platform must be taken into account at design time. To that end, software tools are needed that facilitate detailed simulation of how the timing affects the control system performance. TrueTime is a tool that offers system-wide simulation of the temporal behavior of multi-tasking real-time kernels executing controller tasks. TrueTime also makes it possible to simulate models of common communication network protocols and their influence on networked control loops. This tutorial will be a mini-course about the TrueTime simulator and its intended use in the design of real-time control systems. A number of interactive examples will be presented to visualize the various aspects of the simulator. Features of the simulator that will be demonstrated include; the effect of task scheduling on control performance, task synchronization using monitors and events, interrupt handling and handling of task overruns, and control over wired and wireless networks. |
| Goal: | To present the simulation tool TrueTime that can be used to study the temporal robustness of feedback control loops in resource-constrained embedded and networked systems. |
| Program: |
- Introduction and Background - The TrueTime Simulator - Overview and Usage - Tutorial Examples - Concluding Remarks |