Reduced-size LFT closed-loop modeling of decomposable systems with simplified controller synthesis

Recently, distributed robust output feedback control synthesis has been considered for a subclass of interconnected linear parameter-varying (LPV) systems, referred to as decomposable systems. In the synthesis procedure, the interconnection and the LPV uncertainty are described as linear fractional transformations (LFTs), and conditions derived by the full block S-procedure are solved iteratively. Here different approaches are presented to reduce the size of the LFT channels and thus the number of variables in the synthesis. Furthermore, an alternative synthesis procedure is presented, which in contrast to previously reported results avoids the inversion of multipliers.