Output control of continuous-time uncertain switched linear systems via switched static output feedback

ABSTRACT

This paper is devoted to the robust ipt><img src="/na101/home/literatum/publisher/tandf/journals/content/tcon20/2020/tcon20.v093.i05/00207179.2018.1495341/20200423/images/tcon_a_1495341_ilm0001.gif" alt="" />ipt><img src="//:0" alt="" class="mml-formula" data-formula-source="{"type" : "image", "src" : "/na101/home/literatum/publisher/tandf/journals/content/tcon20/2020/tcon20.v093.i05/00207179.2018.1495341/20200423/images/tcon_a_1495341_ilm0001.gif"}" /><img src="//:0" alt="" data-formula-source="{"type" : "mathjax"}" />iant="script">Hi>i mathvariant="normal">∞i> and guaranteed cost control problems for continuous-time switched linear systems with polytopic uncertainties, considering an output-dependent switching law and a switched static output feedback controller. The proposed method offers new sufficient conditions based on Linear Matrix Inequalities (LMIs) for designing the switching strategy. In order to provide extra free dimensions in the solution space, some conditions become a special class of Bilinear Matrix Inequalities (BMIs). Therefore, the hybrid algorithm Differential Evolution–Linear Matrix Inequality is proposed for obtaining feasible solutions of this NP-hard problem. Theoretical analyses and numerical examples show that these new procedures reduce the design conservatism of two recent known methods for solving the presented control problems. Besides, a practical application of the method in the design and simulation of a robust switched controller of a switched semi-active suspension is performed.     

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Influence of asymmetric etching on ion track shapes in polycarbonate

By combining low-energy ion irradiation with asymmetric etching, conical nanopores of controlled geometry can be etched in polycarbonate (PC). Cone bases vary from 0.5 to 1 μm. Top diameters down to 17 nm are reached. When etching from one side, the pH on the other side (bathed in neutral or acidic buffer) was monitored. Etching temperature ranged from 65 °C to 80 °C. Pore shape characterization was achieved by electro replication combined with SEM observation. The tip shape depended on whether an acidic buffer was used or not on the stopped side.     

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