Robust sampled-data control

Ankara : Department of Electrical Engineering and Institute of Graduate Studies, Bilkent Univ., 1995.Thesis (Ph.D.) -- Bilkent University, 1995.Includes bibliographical references leaves 73-75.Robust control of uncertain plants is a major area of interest in control theory. In this dissertation, robust stabilization of plants under various classes of structural perturbations using sampled-data controllers is considered. It is shown that a controllable system under bounded perturbations that satisfy certain structural conditions can be stabilized using high-gain sampled-data state feedback control, provided that the sampling period is sufficiently small, with generalizations to decentralized control of interconnected systems. This result is then modified so as to enable adapting the gain and the sampling periods of controllers online. Finally another design methodology is given which enables the controllers to operate on the sampled values of output only, instead of full state measurements.Ocalı, OganPh.D

Applications of Singular Perturbation Techniques to Control Problems

Coordinated Science Laboratory was formerly known as Control Systems LaboratoryJoint Services Electronics Program / N00014-79-C-0424National Science Foundation / NSF ECS 82-1763

Some results on optimal control with unilateral state constraints

International audienceIn this paper, we study the problem of quadratic optimal control with state variables unilateral constraints, for linear time-invariant systems. The necessary conditions are formulated as a linear invariant system with complementary slackness conditions. Some structural properties of this system are examined. Then it is shown that the problem can benefit from the higher order Moreau's sweeping process, that is, a specific distributional differential inclusion, and from ten Dam's geometric theory [A.A. ten Dam, K.F. Dwarshuis, J.C. Willems, The contact problem for linear continuous-time dynamical systems: A geometric approach, IEEE Trans. Automat. Control 42 (4) (1997) 458–472; A.A. ten Dam, Unilaterally Constrained Dynamical Systems, Ph.D. Thesis, Rijsuniversiteit Groningen, NL, available at http://irs.ub.rug.nl/ppn/159407869, 1997] for partitioning of the admissible domain boundary (in particular for the case of multivariable systems). In fact, the first step may be also seen as follows: does the higher order Moreau's sweeping process (developed in Acary et al. [V. Acary, B. Brogliato, D. Goeleven, Higher order Moreau's sweeping process: Mathematical formulation and numerical simulation, Math. Programm. A 113 (2008) 133–217]) correspond to the necessary conditions of some optimal control problem with an extended integral action? The knowledge of the qualitative behaviour of optimal trajectories at junction times is improved with the approach, which also paves the way towards efficient time-stepping numerical algorithms to solve the optimal control boundary value problem