Control problems in super-articulated mechanical systems

Control of super-articulated mechanical systems (SAMS: controlled mechanical system in which the dimension of the configuration space exceeds the dimension of the control input space) is studied. As a starting point, a graphical characterization of general SAMS is developed in which a so-called control flow diagram (CFD) is constructed to represent the interaction forces among the degrees of freedom of the system; three types of structure, namely, the chain structure, the tree structure and isolated points, are identified; degree of complexity of the system is defined based on the structure of the system. A systematic backstepping type controller design is proposed for systems with a chain structure to achieve global asymptotic stability and trajectory tracking. Such a controller design itself illustrates the sufficient conditions for the existence of smooth feedback control such that the systems with a chain structure can be globally asymptotically stabilized. The connection of the authors´ control algorithm with existing results is discussed