In this paper, we consider the L∞-bounded robust control problem for a class of nonlinear cascade systems with disturbances. Sufficient conditions are provided under which a hard bound is imposed on the system performance measure. The backstepping approach is used for controller design. Examples are provided to illustrate the method. Key-words. Nonlinear cascade systems, L∞ bound, robust contro...

Abstrad-Screening tools for control structure selection in the presence of model/plant mismatch are developed in the context of the Structured Singular Value (p) Theory. The developed screening tools are designed to aid engineers in the elimination of undesirable control structure candidates for which a robustly performing controller does not exist. The screening tools are examined on a multi-c...

We propose an optimal control approach to robust control design. Our goal is to design a state feedback to stabilize a system under uncertainty. We translate this robust control problem into an optimal control problem of minimizing a cost. Because the uncertainty bound is reeected in the cost, the solution to the optimal control problem is a solution to the robust control problem. Our approach ...

Decentralized robust controller design problem for large-scale interconnected systems which involve uncertainties in the system matrices and uncertain time-delays is considered. An error bound, which accounts for the neglected interactions between the subsystem models and uncertainties in the interactions, in the subsystem models, and in the time delays is first derived using overlapping decomp...

In this paper we deal with design problems of active noise control systems with a pair of loudspeakers, in order to improve the system performance achieved by a single loudspeaker presented in our previous study where advantages of robust control (sampled-data H∞ control) design have been shown by comparing to the existing adaptive control based design. Firstly, as a pair of loudspeakers, the S...

In certain types of robust control techniques, it is common having to deal with control problems where the specifications, described in the time domain, need to be translated to the frequency domain. This usually happens in techniques, such as Quantitative Feedback Theory, where the control problem is developed in the frequency domain. Therefore, not only process plants and disturbances should ...

This paper presents a Converse Lyapunov Function Theorem motivated by robust control analysis and design. Our result is based upon, but generalizes, various aspects of well-known classical theorems. In a unified and natural manner, it (1) allows arbitrary bounded time-varying parameters in the system description, (2) deals with global asymptotic stability, (3) results in smooth (infinitely diff...

The paper presents robust controller design for systems with uncertain transport delays. Robust PI controllers are designed using approach, which combines the method based on plotting the stability boundary locus in the (kp, ki)-plane with the pole-placement method. The approach enables to assure robust stability of the closed loop as well as the quality of the control response prescribed by th...

A robust control approach is developed to control robot in the task space using sliding mode by support of feedback linearization control and backstepping method, in this study. The bounds of uncertainties applied in the sliding mode control are reduced by applying feedback linearization. This provides a robust control system with a less error. The back-stepping method is used to define a linea...