Uniform ultimate boundedness for underactuated mechanical systems as mismatched uncertainty disappeared

We propose to design control for uncertain underactuated mechanical systems. The underactuated mechanical system is to follow prescribed holonomic or nonholonomic constraints. The uncertainty in the system does not in general fall within the range space of the input matrix, which is a major obstacle for control design. To resolve this difficulty, we decompose the uncertainty into matched uncertainty and mismatched uncertainty in a unique manner...