An architecture for implementation of multivariable controllers

An architecture for implementation of multivariable controllers is presented in this paper. The architecture is based on the Youla-Jabr-Bongiorno-Kucera param-eterization of all stabilizing controllers. By using this architecture for implementation of multivariable con-trollers, it is shown how it is possible to change from one multivariable controller to another multivariable controller online in a smooth way with guarantee for closed loop stability. This includes also the case where the controllers are unstable. Gain scheduled controllers can be implemented in this architecture. The general architecture for smooth online changes of multivariable controllers can also handle the start up and close down of multivariable systems. Furthermore, the start up of unstable multivariable controllers can also be handled in this architecture. Finally, implemen-tation of (unstable) controllers as a stable Q parameter in a Q-parameterized controller can also be achieved.

Design of fault detectors using ℋ∞ optimization

The problem of detecting and/or isolating faults in dynamical systems is assessed. In contrast to previous approaches, the residual vector is considered to be a design variable as a free transfer function in addition to the actual filter which is supposed to minimize the residual. Some main directions are suggested, and a numerical algorithm implementing part of these is proposed