This project focuses on the topic of robust control of mechanical systems. Robustness is required because of the nonlinear and uncertain character of such systems. The robust control problem is the problem of designing a fixed, or deterministic state feedback control to stabilize a dynamical system with significant bounded uncertainties while meeting the design requirements. The Lyapunov approach to robustness, one of several currently popular approaches, will be used in this project. Current shortcomings associated with the approach include (1) the control makes the system only uniformly ultimately bounded and not asymptotically stable, (2) the control only applies to systems which satisfy the so called 'matching condition', and (3) it is usually necessary to make assumptions about the allowable size of the system uncertainties. The objectives of this project are to overcome these shortcomings. The research is aimed at making robust control of nonlinear systems a practical tool.
