Abstract of Thesis presented at COPPE/UFRJ as a partial fulfillment of the requirements for the degree of Doctor of Science (D.Sc.)
Output-Feedback Sliding Mode Control of Uncertain Multivariable Systems
José Paulo Vilela Soares da Cunha
March/2004
| Advisors: |
Liu Hsu
Ramon Romankevicius Costa
|
| Department: |
Eletrical Engineering |
Sliding mode model-reference controllers for uncertain multivariable systems are proposed in this Thesis. The control laws are based on unit vector control, outputfeedback and model-reference adaptive control formulation. The proposed strategy is an extension of a variable structure controller devised for single-input-single-output (SISO) systems. A class of multivariable systems subject to nonlinear disturbances which depends on the unmeasurable state variables is considered. The main features of the proposed approach are as follows: (i) the control systems is globally exponentially stable with respect to a small residual set; (ii) the uncertainties can be unmatched with respect to the input and, (iii) a simple Hurwitz condition is imposed on the plant high frequency gain matrix. The proposed scheme is free of the peaking phenomenon, which is usual in some observer based controllers. Finally, a controller for uncertain SISO systems based on a peaking free high gain observer is developed.
