Implementation of algebraic controllers for non-conventional sampled-data systems
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Nowadays, in industrial control applications, is rather usual to sample and update different variables at different rates, although it is common to consider all these activities equally and regularly spaced on time. These applications are implemented on real-time operating systems by decomposing them into several tasks in such a way that pre-emption and blocking may appear due to task priorities and resource sharing. This could imply the presence of delays, leading to a non-regular periodic behaviour and, as a result, the control performance can be degraded. In order to undertake this problem, a solution based on a modelling methodology for non-conventional sampled-data systems is proposed. This technique permits the consideration of any cyclic sampling pattern. Thus, these delays can be considered in the modelling step, and later on, a non-conventional controller based on this model can be designed. In this way, if the considered non-conventional control system is implemented assuming a real-time operating system (Tornado-VxWorks, in this case), a clear performance improvement can be observed.
KeywordsReal-time operating systems Modelling Sampled-data control Multirate Control design
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- Albertos P, Crespo A, Ripoll I, Vallés M, Balbastre P (2000) RT control scheduling to reduce control performance degrading. In: Proceedings of the 39th IEEE Conference on decision and control, SydneyGoogle Scholar
- Araki M (1993) Recent development in digital control theory. In: Proceedings of the 12th IFAC World Congress, SydneyGoogle Scholar
- Cuenca A (2004) Modelado, análisis y diseño de sistemas de control con muestreo no-convencional. Thesis. Department of Systems Engineering and Control. Politechnical University of Valencia. (In Spanish)Google Scholar
- Godbout LF, Jordan D, Apostolakis IS (1990) Closed-loop model for general multirate digital control systems. IEE Proceedings 137(5):329–336Google Scholar
- Khargonekar PP, Poolla K, Tannenbaum A (1985) Robust control of linear time-invariant plants using periodic compensation. IEEE Trans. Autom Contr AC-30(11):1088–1096Google Scholar
- Salt J (1992) Control de procesos industriales con muestreo no-convencional. Thesis. Department of Systems Engineering and Control. Politechnical University of Valencia. (In Spanish)Google Scholar
- Salt J, Cuenca A, Albertos P (2002) Algebraic design of multirate controllers. 15th IFAC World Congress b’02. BarcelonaGoogle Scholar
- Thomas HW, Lutte NP (1972) Z-transform analysis of nonuniformly sampled digital filters. Proc. IEE 119(11)Google Scholar
- Vélez CM, Salt J (2000) Simulation of irregular multirate systems. In: Proceedings of 8th symposium on computer aided control system design. salford, United KingdomGoogle Scholar