Advertisement

Complex Task Implementation in Ada

  • Alfons Crespo
  • Patricia Balbastre
  • Silvia Terrasa
Conference paper
Part of the Lecture Notes in Computer Science book series (LNCS, volume 2043)

Abstract

Control applications require defining several parallel activities to model the environment. Periodic tasks model the activities to be executed at periodic instants of time. While the process of control design is focused on obtaining the regulator, later on translated into an algorithm, the software design is focused on producing pieces of software that will be executed concurrently under a scheduler. Nowadays, more and more applications require complex computation and the use of complex algorithms that can compromise the response time of the system. The activities involving a control loop task can be structured in some parts: data acquisition, computation of the control action, optional activities and output of the control action. This decomposition is useful to improve the control performance and reduce delays due to the scheduler. This paper shows how to implement complex real-time control applications by means of periodic tasks in Ada, using a task decomposition.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. [1]
    Albertos P., Crespo A., Ripoll I., Vallés M., Balbastre P., “RT control Scheduling to reduce control performance degrading”. 39th IEEE Conference on Decision and Control CDC2000. December 12–15. Sydney.Google Scholar
  2. [2]
    Audsley N.C., Burns A., Richardson M.F., Tindell K.W., Wellings A.J., “Applying New Scheduling Theory to Static Preemptive Systems”. Sowtfare Engineering Journal 8(5) pp. 284–292, 1993Google Scholar
  3. [3]
    Balbastre P., Ripoll I., Crespo A., “Control Tasks Delay Reduction under Static and Dynamic Scheduling Policies” 7th International Conference on Real-Time Systems and Applications (RTCSA 2000) 12–14 December 2000 Cheju Island, South Korea.Google Scholar
  4. [4]
    A. Burns and A. Wellings, Real-Time Systems and their Programming Languages (2nd Edn), Addison-Wesley, 1996.Google Scholar
  5. [5]
    A. Burns and A. Wellings, Concurrency in Ada, Cambridge University Press, 1995.Google Scholar
  6. [6]
    Crespo, A., Ripoll I., and P. Albertos. “Reducing Delays in RT control: the Control Action Interval” IFAC World Congress, Beijing 1999.Google Scholar
  7. [7]
    Leung J., Whitehead J., “On the Complexity of Fixed-Priority Scheduling of Periodic, Real-Time Tasks”, Performance Evaluation, Vol. 2(4), pp. 237–250, December 1982.CrossRefzbMATHMathSciNetGoogle Scholar
  8. [8]
    Liu C. L., Layland J. W., “Scheduling Algorithms for Multiprogramming in a Hard Real-Time Environment”. Journal of the ACM, vol. 20,no. 1, pp. 46–61, 1973.zbMATHCrossRefMathSciNetGoogle Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 2001

Authors and Affiliations

  • Alfons Crespo
    • 1
  • Patricia Balbastre
    • 1
  • Silvia Terrasa
    • 1
  1. 1.Universidad Politécnica de Valencia (Spain)ValenciaSpain

Personalised recommendations