A Fuzzy Logic Approach to the Concept of Manipulability in Mechanics

Manipulability is a measure of performance for mechanical manipulators. Intuitively, Manipulability at a point of a manipulator workspace measures how easy is to reach the neighbour points. Currently, this value is obtained using an algebraic formula based on the Jacobian of the manipulator that is not very intuitive. Also, this formulation defines Manipulability as a continuous function of the workspace coordinates; however, due to natural restrictions for the mechanical implementation, actual devices include physical limits where this algebraic formulation produces incoherent Manipulability values. This work presents a new formulation based on fuzzy rules that provides a more intuitive definition of Manipulability. This formulation solves the boundary problem, while remains consistent with the algebraic one in those spatial zones where this works correctly. In order to demonstrate the advantage of this new approach, the Manipulability of a well known commercial haptic device has been studied comparing both formulations