This three-year award supports US-France cooperative research aimed at the design of control laws for nonholonomic robot systems. Nonholonomic systems are mechanical systems with motion constraints. The collaboration involves Panagiotis Tsiotras of the University of Virginia and the research group led by Carlos A. Canudas de Wit at the Automation Laboratory of the Ecole Nationale Superieure d'Ingenieurs Electriciens in Grenoble, France. The investigators will develop a methodology for constructing non- smooth, time-invariant, feedback control laws for special classes of nonholonomic systems, which include the case of mobile robots. Implementation of the control laws via force or torque actuators and robustness to external disturbances will be examined. The controls will then be experimentally tested and compared to other methods using mobile robots at the University of Virginia and at the Automation Laboratory in Grenoble. The US investigator brings to this collaboration expertise in stabilization and control of rigid bodies. This is complemented by the French investigator's expertise in nonlinear control theory and control of nonholonomic systems. The project will advance knowledge of new nonlinear algorithms for nonholonomic systems with fast convergence rates and could be applied to autonomous or semi-autonomous mobile robots and underactuated mechanical systems.