ALMOST DECOUPLING OF UNCERTAIN MULTIVARIABLE SYSTEMS

An effective almost decoupling theory using an internal model referenc e loop is developed for linear uncertain multivariable systems. Based on non-negative matrix theory, a useful design guide is derived to ach ieve the generalized diagonal dominance condition for the internal mod el reference loop. Using a Perron root, a sufficient condition is give n to guarantee the inverse transfer matrix to be generalized diagonall y dominant for all plants in a given family. One of the main features of the proposed scheme is the reduction of uncertainty in the resultan t compensated internal loop system, which makes the subsequent design process of the individual channels using standard SISO techniques much simpler.