TIMERS - Timing analysis, modeling and evaluation of RTS
|
|
Leader:
|
Christer Norström
|
|
Members:
|
Christer Norström, Jukka Mäki-Turja, Hans Hansson, Sasikumar Punnekkat
Former: Kristian Sandström |
|
Keywords:
|
timing analysis, modeling, real-time systems, design, scheduling
|
|
Status:
|
finished
, start date: 1999
|
|
Partners:
|
Volvo CEC, TietoEnator, DAMEK KTH (Martin Törngren)
|
|
Funding:
|
KK-foundation, MdH
|
|
Web:
|
Project web page
|
|
|
| |
Overview
In this project, we address various issues related to the synthesis, modeling, analysis and implementation of embedded systems in 'real' industrial settings. This project can be described as the second phase of the DOORS project, since many of the industrial issues addressed here has arisen out of problems faced and our experiences during that project. The project includes:
- Architecture design and analysis, that is, how is an architecture for an embedded system designed and analyzed with respect to both functional and non-functional properties.
- Definition of new architecture description languages with a precise syntax and semantics to enable both analysis and synthesis to a resource structure.
- Mapping of architecture to a resource structure, especially we are studying an unified approach to priority assignment for fixed priority systems.
- Development of new scheduling algorithms, which could provide 'optimal' performance in terms of control performance (rather than just feasibility). Another objective is to provide sufficient motivation for the industry and help them to select the 'right' scheduling paradigm suitable to the application domain and task timing characteristics.
- Fault modeling and studies on the effects of errors on timing analysis
- Development of tools, which supports analysis as well as synthesis to resource structures.
|
| |
Latest project publications
[ Show all publications ]
| | Managing Complex Temporal Requirements in Real-Time Control Systems, Kristian Sandström (former), Christer Norström, 9th IEEE Conference on Engineering of Computer-Based Systems, IEEE, Sweden, April, 2002 |
| | Enforcing Temporal Constraints in Embedded Control Systems, Kristian Sandström (former), Ph D Thesis, Royal Institute of Technology, April, 2002 |
| | Managing Temporal Constraints in Control Systems, Kristian Sandström (former), Christer Norström, MRTC report ISSN 1404-3041 ISRN MDH-MRTC-45/2002-1-SE, Mälardalen Real-Time Research Centre, Mälardalen University, April, 2002 |
|
| |
Results achieved
- Kristian Sandström presented his thesis, Enforcing Temporal Constrints in Embedded Control Systems, in April 2002. The thesis contributes with methods for enforcing temporal constraints in embedded control systems. The results include an industrial case study pointing out limitations in classic real-time models and giving indications of engineering needs. Moreover, a method is presented for pre-run-time scheduling of periodic control activities under the interference of sporadic interrupts. Furthermore, the thesis presents a method for enforcing complex temporal constraints using standard priority based real-time operating systems. Finally, the work includes a method for management of communication resources in distributed systems.
- Software architectures: An extensive report [Wal99], providing the state-of-the-art in the area of software architectures. It concerns the definition of software architecture, architecture description languages, architectural views, architectural analysis with respect to both functional and non-functional attributes, and trade-off analysis. We also continued our efforts in integrating formal methods and real-time analysis techniques [Nor99].
- Constructive Feedback when using off-line scheduling: When applying off-line scheduling in industrial projects, engineers are faced with a problem of how to provide constructive feedback to the user in cases when a feasible schedule can not be found. The problem was accentuated when the engineers at Volvo Construction Equipment Components AB used a off-line scheduler. An algorithm was developed together with a prototype tool to make this analysis. This work is presented in [All99].
- Real-time control systems:. This work has focused on closing the gap between control theory and real-time scheduling theory, by developing a task model that meets the control model requirements. Different scheduling techniques have been evaluated, which confirmed that many conventional task models are hard to use when designing multi-rate control systems, if one wants an effective implementation. This work and results are presented in [San99] and [San99b].
- Fault models and response time analysis of CAN: We have recognized the inadequacies of existing fault models and have proposed a general fault model to take account of single errors as well as burst errors. We have demonstrated our model and analysis using a popular case-study, the details of which can be seen in [Sas99]. We also developed a tool for the calculation of message latencies for CAN bus under different fault models. This tool, viz., ‘SAUS’ (Schedulability Analysis Using Spreadsheets) is quite general purpose, flexible and can perform quick ‘what-if’ analysis to aid designers.
- Real-time Systems book: The need for an appropriate textbook for undergraduate education has been long-felt and a major step in this direction has been taken. The aim of the book is to provide useful results for designing real systems. The first version of the book has been printed in October 99, as a compendium. This covers real-time operating systems, scheduling, design, and distributed systems.
Courses and seminars
A number of courses in real-time systems have been given in co-operation with Nohau.
Thesis:
Papers:
|
| |
Future work
We intend to continue our research along the lines specified in the project description, with added interaction with industry at different stages to validate our models and evaluate the usefulness of our results.
|
|
|
|
