Adaptive robust control schemes for a class of nonlinear uncertain descriptor systems

This paper presents new adaptive robust control schemes for a class of nonlinear uncertain descriptor systems. Taking both the structured and unstructured uncertainties into consideration, the first control scheme achieves asymptotic stability of the closed-loop descriptor system. To avoid any potential problems such as parameter drift by unmodeled dynamics, in the second control scheme the adaptation is ceased when the control performance gets into the desirable region. The new control scheme guarantees the uniform boundedness of the system and, at the same time, the system will enter the desired zone, which can be arbitrarily designated, in a finite time.