Redundant nonholonomic mechanical systems: characterization and control

This paper introduces the notion of kinematic redundancy in nonholonomic me chanical systems, identifies some of the interesting properties which resul t because of the presence of the redundancy, and initiates a study of the c ontrol and application of these systems. It is shown that kinematic redunda ncy in nonholonomic system can be exploited both to simplify the problem of controlling these systems and to enhance their performance capabilities. M oreover, it is demonstrated that these results can be obtained even in the presence of considerable uncertainty regarding the system model. The propos ed ideas are illustrated through the study of three example systems: a spac e robot, a mobile manipulator, and a tractor-trailer system with two steeri ng inputs (fife truck).