An application is presented of1 synthesis to the robust control of a large  exible space structure experimental testbed called Daisy. A perturbed left-coprime factorization of Daisy’s dynamics is used to capture the uncertainty in the modes. Designs of the 1 synthesis controller based on left-coprime factorizations of 46th-order collocated and noncollocatedmodels of Daisy are presented togethe...

We develop control laws for the pendular motion of a spinning tethered satellite system. The control laws are developed using a simplified system model that contains unknown disturbance terms that account for unmodeled dynamics in the simplified model. Principles of sliding mode and adaptive nonlinear control design are used to develop control laws that drive the pendular motion to a desired re...

Observer design is classically considered as a dual problem to state feedback. But very few results address this issue in the context of uncertain system, at least in comparison of robust state-feedback design. This fact has motivated us for studying robust design of both state-feedback gains and Luemberger-like observers and we in particular show that in case of uncertain systems these two des...

Moat realistic control problems involve both some type of time-domain constraints and model uncertainty. However, there presently exist few design methods capable of simultaneously addressing both issues. We recently proposed to address this class of problem by using a "constrained robustness measure", generated by a constraint-set induced operator norm, to assess the stability ptoperties of a ...

In this paper, we evaluate the stability margin of a Fiat Dedra engine model to explore possible applications of theoretical achievements in the parametric approach to robust control problems. The study is based on two versions of the model with uncertainties. One is the original model, which has a multilinear characteristic polynomial, while the other is an affine-linearized model which is obt...

A robust controller is designed for a system consisting of two carts coupled by a spring. Special attention is given to the input saturations. This problem was posed within a benchmark collection for robust control techniques and treated for example at the 1992 ACC. μ analysis and simulation studies illustrate our design.

In this paper new techniques are developed for the analysis of linear time-varying (LTV) systems. These lead to a formally simple treatment of robust control problems for LTV systems, allowing methods more usually restricted to timeinvariant systems to be employed in the time-varying case. As an illustration of this methodology, the so-called H1 synthesis problem is solved for LTV systems.

This paper deals with the robust stability of soft variable-structure controls. More precisely, the control of linear plants subject to parametric uncertainty and actuator saturation is considered. Earlier works are summarized and new results are presented in this paper. It is shown that for all considered types of soft variable-structure controls, the robustness analysis leads to parameter-dep...

This paper proposes a robust control of doublefed induction generator of wind turbine to optimize its production: that means the energy quality and efficiency. The proposed control reposes in the sliding mode control using a multimodel approach which contributes on the minimization of the static error and the chattering phenomenon. This new approach is called sliding mode multimodel control (SM...

This paper describes Nonconvex Polygon Interval Arithmetic (NPIA) and its implementation. NPIA is the arithmetic defined on the set of all polygons in the complex plane, and it is very useful to compute estimates of value sets of transfer functions including uncertain physical parameters in a reasonable computing time. If the transfer function can be written in such a way that each uncertain pa...