A hierarchical approach to adaptive disturbance attenuation combining switching and tuning

In this paper, an algorithm combining switching and tuning is proposed as a solution to the problem of adaptive disturbance attenuation. A high-level switching logic selects the controller providing the best potential performance within a pre-designed family; then a tuning procedure aims at finding a local refinement of the selected controller in order to improve its attenuation capabilities, and a low-level switching logic is used to decide whether to substitute the controller with its refinement or not. The control architecture is designed by adopting a particular implementation which ensures stability under any arbitrary switching sequence. It is shown that an arbitrary attenuation level can be achieved by adopting appropriately defined functionals. Simulation results are provided to show the validity of the proposed algorithm.