Please contact Jean-Marc Biannic for any feedback (biannic@onera.fr).
Saturations (magnitude, rate, acceleration) are always present in control systems and must be taken into account either a priori or a posteriori to avoid loss of performance and possibly destabilization. This is classicaly achieved by an anti-windup structure as shown on, the figure below.
Figure 1: Anti-windup structure.
The anti-windup compensator $J(s)$ may be computed in several ways (see [1] for details):
The tools included in the SAW library permit to set (with the Simulink interface) and solve easily the above two problems with static, fixed-order and full-order compensators. The main three routines of the library are:
The best way to start with the tools is to run the examples contained in a specific folder of the package.
The current version of the SAW Library is based on three main routines and a Simulink interface which may be used to set up easily the anti-windup design problem. Click here to download the package.
[1] J-M. Biannic, S. Tarbouriech. Optimization and implementation of dynamic anti-windup compensators in aircraft control systems with multiple saturations. Control Engineering Practice. 17(6) : 703-713, June 2009.
[2] C. Roos, J-M. Biannic. A convex characterization of dynamically-constrained anti-windup controllers. Automatica. 44(9) : 2449-2452, September 2008.
[3] G. Ferreres, J-M. Biannic. Convex design of a robust anti-windup controller for an LFT model. IEEE Transactions on Automatic Control. 52(11) : 2173-2177, November 2007.
[4] J-M. Biannic and P. Apkarian. Anti-windup design via nonsmooth multi-objective H∞ optimization. In the proceedings of the American Control Conference, pp. 4457-4462. San Francisco, CA, USA. June 29 - July 01, 2011.