Multivariable decentralized integral controllability

Publisher Website
Google Scholar
Abstract
General existence conditions under which the stability of the individual loops of a multivariable system in a given compact and bounded gain space imply the global asymptotic stability of the multivariable system in the same space are very useful in practice and essentially indicate when in principle it is possible to obtain stable closed loop performance of a multivariable system by tuning every loop separately. Such conditions are particularly useful for fault tolerant control of multivariable systems. This paper gives the required necessary and sufficient conditions but proceeds from there to derive the stronger existence conditions for stability in the gain space when every loop contains an integrator. Such conditions are called decentralized integral controllability and are needed to guarantee not only robust stability in the gain space but also zero steady state performance errors in the same space, thus assuring system fault tolerance.