9402229 Spong In this research project, fundamental issues related to the design, analysis, and real-time implementation of robust and adaptive control laws for underactuated mechanical systems are investigated. The class of systems is quite broad and encompasses balancing and walking robots, a variety of flexible structures including flexible link and flexible joint robots, as well as robot models that include actuator dynamics, and many of the classical control problems such as ball and beam, and cart-pole systems. The integrating theme of the research effort is the utilization of the integrator backstepping method for the design of underactuated systems. Currently, powerful design techniques, such as feedback linearization, singular perturbations, and passivity based methods, are available for fully actuated systems. These techniques are extended for their applicability to underactuated systems. ***
