Date of final exam: 04/02/1999

E-mail: l.giacomini@aston.ac.uk

Tutor: Prof.  G. Bartolini, Università di Cagliari

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Adaptive and second order sliding mode control of nonlinear uncertain systems   ___________________________________________________________________________________________________________

Advisor:

Prof.  G. Bartolini, Università di Cagliari, Prof.  A. Ferrara, Università di Pavia,

Summary of the thesis

In this thesis has been presented an adaptive/second order sliding mode control algorithm for uncertain nonlinear systems. The reasons to couple backstepping with second order sliding mode are - improve robustness of the backstepping design procedure; - reduce backstepping computational load; - improve transients behavior; - obtain a more convenient feasibility region. The reason to couple second order sliding mode control with backstepping is to be able to apply second order sliding mode control to systems with non matched uncertainties. These points have been illustrated throughout the thesis with simulative examples to evidence the benefits of the combined procedure, and to attempt to clarify the procedures themselves. An introduction to the two control tools is provided in the initial chapters, and a very short appendix with some essential stability theorems is provided. Despite the combined algorithm for one kind of backstepping would be sufficient to explain the control philosophy, it has appeared necessary to show more then one, first to encrease clearness (the description starts from the easiest scheme to arrive to the non parametric case), second to make apparent the flexibility of the design.
 

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