Improving decentralized variable-structure control of uncertain linear large-scale system

Chiang's 1993 paper still suffers from two shortcomings: large number of switching variables in decentralized controller and high value of control input. This paper aims to lessen as much as possible these two shortcomings. Gao's suggestion were adopted to achieve a big lessening of Chiang's shortcomings. Gao's suggestion is essentially that ultimate sliding mode control should be used to get better results in many engineering problems. Gao's suggestion is indeed very effective for decentralized variable-structure robust control of an uncertain large-scale system. Bounded uncertain interconnection terms, system parameter variations, and external disturbances were considered. Five equations were given, as the mathematical expressions of the control law. As compared with Chiang's method, this method reduces the number of switching variables in each decentralized controller from four to one. We have given the simulation results of a numerical example which show that control input is much reduced.