A Design Methodology for Weakly-Hard Real-Time Control

The problem of the integrated control and weakly-hard real-time scheduling is addressed. First, an abstract model of control tasks execution is introduced, allowing the establishment of a formal relationship linking control performance to deadline misses. Then, the notion of accelerable control task is introduced. An accelerable control task has the property that more executions are performed, better is the control performance. Thanks to this latter property, it becomes straightforward to design the control laws according to the average execution times of control tasks, and guaranteeing that in the worst-case scenario, the minimal allowable performance will be achieved. Based on Bellman optimality principle, sufficient conditions for a given control task to be accelerable are stated. A design method of optimal control laws for the weakly-hard execution model is then proposed.

[1]  Michael D. Lemmon,et al.  On Self-triggered Full-Information H-Infinity Controllers , 2007, HSCC.

[2]  Wei-Kuan Shih,et al.  Algorithms for Scheduling Imprecise Computations with Timing Constraints to Minimize Maximum Error , 1995, IEEE Trans. Computers.

[3]  Jia Ning,et al.  Graceful degradation of the quality of control through data drop policy , 2007, 2007 European Control Conference (ECC).

[4]  Gerhard Fohler,et al.  Analysis and Design of Real-Time Control Systems with Varying Control Timing Constraints , 2002 .

[5]  Pau Marti.  Analysis and Design of Real-Time Control Systems with Varying Control Timing Constraints , 2002 .

[6]  Parameswaran Ramanathan,et al.  A Dynamic Priority Assignement Technique for Streams with (m, k)-Firm Deadlines , 1995, IEEE Trans. Computers.

[7]  Bruno Sinopoli,et al.  Foundations of Control and Estimation Over Lossy Networks , 2007, Proceedings of the IEEE.

[8]  Tamer Basar,et al.  Optimal control of LTI systems over unreliable communication links , 2006, Autom..

[9]  Parameswaran Ramanathan,et al.  Overload Management in Real-Time Control Applications Using (m, k)-Firm Guarantee , 1999, IEEE Trans. Parallel Distributed Syst..

[10]  Alan Burns,et al.  Weakly Hard Real-Time Systems , 2001, IEEE Trans. Computers.

[11]  Mohamed El Mongi Ben Gaid,et al.  Optimal scheduling of control tasks with state feedback resource allocation , 2006, 2006 American Control Conference.

[12]  Dennis Shasha,et al.  Skip-Over: algorithms and complexity for overloaded systems that allow skips , 1995, Proceedings 16th IEEE Real-Time Systems Symposium.

[13]  Olivier Sename,et al.  A reduced polytopic LPV synthesis for a sampling varying controller: Experimentation with a T inverted pendulum , 2007, 2007 European Control Conference (ECC).

[14]  Olivier Sename,et al.  Robust control/scheduling co-design: application to robot control , 2005, 11th IEEE Real Time and Embedded Technology and Applications Symposium.

[15]  Lui Sha,et al.  On task schedulability in real-time control systems , 1996, 17th IEEE Real-Time Systems Symposium.

[16]  Henrik Theiling,et al.  Reliable and Precise WCET Determination for a Real-Life Processor , 2001, EMSOFT.

[17]  Karl-Erik Årzén,et al.  A FEEDBACK SCHEDULER FOR REAL-TIME CONTROLLER TASKS , 2000 .

[18]  Per Stenström,et al.  Timing anomalies in dynamically scheduled microprocessors , 1999, Proceedings 20th IEEE Real-Time Systems Symposium (Cat. No.99CB37054).