Adaptive gain-scheduled H∞ control of linear parameter-varying systems by adding nonlinear feedback schemes

The paper is concerned with a new class of adaptive gain-scheduled H_∞ control of linear parameter-varying (LPV) systems. The plants in this manuscript are assumed to be polytopic LPV systems, but the time-varying parameters in those plants are not available for measurement, and thus, the conventional gain-scheduled control strategy cannot be applied. In the proposed adaptive schemes, the estimates of those unknown parameters are obtained successively, and the current estimates are fed to the controllers to stabilize the plants and to attain H_∞ control performance adaptively. Nonlinear feedback control schemes are also added to suppress the effects of time-varying parameters. Those schemes are derived as a solution of another H_∞ control problem where time-varying terms are regarded as exogenous disturbance to the processes.