Integrated Control and Scheduling

Project no: #7

Karl-Erik Årzén, Klas Nilsson, Ola Dahl

Lund Institute of Technology, Department of Automatic Control and Lund Institute of Technology, Department of Computer Science

Application as pdf, ps, supported by Sigma Exallon Systems AB and DDA Consulting.

Support: 2 PhD students for 2 years decided 98-01-13.

Start 98-05-01 with Anton Cervin and Patrik Person as PhD students.

Continuation proposal 00-08-16

Reports: In ARTES annual report for 97-98, at ARTES RT-grad student day 99, status report page., Second year report 00-08-16, Status report 00-08-16 for Summerschool

Local web: http://www.control.lth.se/~anton/artes/

 

Industry contacts

Ola Dahl ola.dahl@mbox322.swipnet.se

DDA Consulting

Malmö

Project: Integrated Control and Scheduling

 

Jan Johansson Enejder jan.johansson@es.sigma.se

Sigma Exallon Systems AB

Malmö

Project: Integrated Control and Scheduling

 

Krister Tham krister.tham@es.sigma.se

Sigma Exallon Systems AB

Malmö

Project: Integrated Control and Scheduling

Overview

The focus of the project is methods for practical management of hard real-time demands in embedded real-time control software. Two approaches are followed. One idea is to combine control theory and scheduling theory in such a way that the nominal requirements on hard deadlines for control systems can be relieved. The approach taken is based on using dynamic feedback from the scheduler to the controllers and from the controllers to the scheduler. The second, complementary, idea is to use attribute grammars and incremental semantic analysis to carry out on-line interactive analysis of the worst-case timing of the software. The work during the first phase of the project has focused on scheduling of control tasks, task attribute adjustments, WCET analysis and memory usage analysis for object-oriented languages.

Results

1. Patrik Persson,  Licentiate thesis
   Predicting Time and Memory Demands of Object-Oriented Programs
   Date: Wednesday April 12, 2000 at 13:15, LTH, E building, room E:1406
   
   
2. Anton Cervin, Licentiate Thesis
   Towards the Integration of Control and Real-Time Scheduling Design
   Date: May 26, 2000 at 10.15, LTH, M-building, room M:E.

Other results

Scheduling of controller tasks has been investigated. A new iterative deadline-based priority assignment scheme has been developed. A Matlab/Simulink-based tool for co-simulation of real-time control systems and real-time kernels has been developed, and has been made available to the public. The simulator is designed for simultaneous simulation of continuous plant dynamics, real-time tasks, and network traffic, in order to study the effects of the task interaction on the control performance. The kernel also allows experimentation with new scheduling methods.

Techniques for predicting time and memory demands of object-oriented real-time programs have been integrated into the "Skånerost" development environment. The environment explicitly targets an iterative development process, which is particularly important in real-time software development since time and memory demands cannot be determined until the code is written. Design changes due to timing problems become more costly as development progresses, and Skånerost allows such problems to be detected early.

Co-operation

Collaboration with the project industrial partners

There are regular meetings where reserach problems are discussed. The industrial partner will provide case studies and evaluate the development tools at later stages in the project.

International collaboration and relations

There are several international contacts with other universities, primarly with Prof. Lui Sha at University of Illinois at Urbana-Champaign.

Swedish collaborations

This project is a cooperation between Dept. of Computer Science and Dept. of Automatic Control at LTH. There are also collaboaration with several NUTEK projects.

Publications

1. Anton Cervin: Improved Scheduling of Control Tasks. Proceedings of the 11th Euromicro Conference on Real-Time Systems, York, England, June 1999.
2. A. Cervin: The Real-Time Control Systems Simulator---Reference Manual. Internal report TFRT-7592, Department of Automatic Control, Lund Institute of Technology, April 2000.
3. A. Cervin, J. Eker, and L. Sha: Feedback Scheduling of Control Tasks. Submitted to the 39th IEEE Conference on Decision and Control, Sydney, Australia, December 2000.
4. J. Eker and A. Cervin. A Matlab Toolbox for Real-Time and Control Systems Co-Design. In Proceedings of the 6th International Conference on Real-Time Computing Systems and Applications, Hong Kong, China, December 1999.
5. J. Eker, P. Hagander, and K.-E. Årzén: A Feedback Scheduler for Real-Time Controller Tasks. Accepted for publication in Control Engineering Practice, 2000.
6. Sven Gestegård Robertz, Flexible automatic memory management for real-time and embedded systems. Dissertation 18, 2003 LU-CS-LIC: 2003-2. ISSN 1404-1219
7. P. Persson: Live Memory Analysis for Garbage Collection in Embedded Systems. In Proceedings of the ACM SIGPLAN 1999 Workshop on Languages, Compilers, and Tools for Embedded Systems (LCTES'99), Atlanta, GA, May 1999. ACM SIGPLAN Notices 34(7):45-54.
8. P. Persson Using Aliasing Information to Predict Real-Time Garbage Collection In A. Moreira and S. Demeyer (editors): Object-Oriented Technology: ECOOP '99 Workshop Reader, pages 137-138, LNCS 1743, Springer, 1999. Position paper presented at the Intercontinental Workshop on Aliasing in Object-Oriented Systems (in conjunction with ECOOP'99), Lisbon, Portugal, June 1999.
9. Patrik Persson. Bounding The Execution Time of Method Calls Combining Static Analysis and Dynamic Class Loading. ARTES Graduate Student Conference 2000.
10. P. Persson, A. Cervin, and J. Eker: Execution-Time Properties of a Hybrid Controller. Internal report TFRT-7591, Department of Automatic Control, Lund Institute of Technology, April 2000.
11. Patrik Persson and Görel Hedin: Interactive Execution Time Predictions using Reference Attributed Grammars. Proceedings of WAGA '99: Second Workshop on Attribute Grammars and their Applications, Amsterdam, The Netherlands, March 1999.
12. P. Persson and G. Hedin. An Interactive Environment for Real-Time Software Development. In Proceedings of the 33rd International Conference on Technology of Object-Oriented Languages and Systems (TOOLS Europe 2000), St. Malo, France, June 2000. IEEE Computer Society Press.
13. K.-E. Årzén: A Simple Event-Based PID Controller. In Proceedings of the IFAC World Congress, Beijing, China, July 1999.
14. K.-E. Årzén, B. Bernhardsson, J. Eker, A. Cervin, K. Nilsson, P. Persson, and L. Sha: Integrated Control and Scheduling. Internal report TFRT-7582, Department of Automatic Control, Lund University, August 1999.
15. K.-E. Årzén and A. Cervin: A Simple Event-Based PID Controller. Submitted to Control Engineering Practice, 1999.
16. K.-E. Årzén, A. Cervin, J. Eker, B. Bernhardsson, L. Sha: Towards the Integration of Control and Real-Time Scheduling Design. In submission 2000.
17. K.-E. Årzén, A. Cervin, J. Eker, and L. Sha: An Introduction to Control and Real-Time Scheduling Co-Design. Submitted to the 39th IEEE Conference on Decision and Control, Sydney, Australia, December 2000.

Presentations

1. P. Persson: Interactive Timing and Memory Predictions for Real-Time Java Third Annual European Conference on Java and Object-Orientation (JAOO'99), Aarhus, Denmark, September 1999.
2. Using Aliasing Information to Predict Real-Time Garbage Collection Intercontinental Workshop on Aliasing in Object-Oriented Systems (IWAOOS'99, in conjunction with ECOOP'99), Lisbon, Portugal, June 1999.
3. P. Persson: Live Memory Analysis for Garbage Collection in Embedded Systems ACM SIGPLAN 1999 Workshop on Languages, Compilers, and Tools for Embedded Systems (LCTES'99), Atlanta, GA, May 1999.
4. Interactive Execution Time Predictions using Reference Attributed Grammars Second Workshop on Attribute Grammars and their Applications (WAGA'99), Amsterdam, The Netherlands, March 1999.