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A design method for the decentralised timevarying discretetime outputfeedback control of linear timeinvariant plants with unstable unstructured decentralised fixed modes (UDFM) is introduced. The design method uses generalised sampleddata hold functions to eliminate the UDFMs and to decouple the discretetime equivalent model of the plant into independent input–output channels. Through this structural change, the plant becomes suitable for a stabilising highsamplingrate controller that induces twotimescale motions (TTSM) in the closedloop system. As a result, the discretetime controller is likewise decoupled into distinct local agents and the TTSM closedloop system is decentralised.
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