Abstract:

A class of nonlinear systems with uncertainties are transformed into certain forms. The existence conditions of the transformation are proved. Then based on the variable structure control theory, robust controllers for systems in these forms are developed under perturbations and uncertainties with known bounds. The existence and stability of the sliding modes are discussed and proved.When these bounds are unknown, on line adaptive techniques are employed to estimate the bounds, and corresponding robust controllers are also developed. Linearization methods are used to design sliding modes in the variable structure control.

Key words: nonlinear systems, robust control, variable structure control, sliding modes