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When a manipulator suuers a joint failure, its performance can be signiicantly affected. If the failed joint is locked, the resulting manipulator Jacobian is given by the original Jacobian, except that the column associated with the failed joint is removed. The rank of the resulting Jacobian then determines if the manipulator still has the ability to(More)
—This work considers kinematic failure tolerance when obstacles are present in the environment. It addresses the issue of finding a collision-free path such that a redundant robot can successfully move from a start to a goal position and/or orientation in the workspace despite any single locked-joint failure at any time. An algorithm is presented that(More)
—In this paper, the authors examine the problem of designing nominal manipulator Jacobians that are optimally fault tolerant to one or more joint failures. Optimality is defined here in terms of the worst-case relative manipulability index. While this approach is applicable to both serial and parallel mechanisms , it is especially applicable to parallel(More)
— In addition to possessing a number of other important properties, kinematically redundant manipulators are inherently more tolerant to locked-joint failures than non-redundant manipulators. However, a joint failure can still render a kinematically redundant manipulator useless if the manipulator is poorly designed or controlled. This paper presents a(More)
Character states during sporulation have been used to segregate and describe many small-spored species of Alternaria, but some are not supported by published phylogenetic analyses. The conidiation response of Alternaria gaisen was characterized by selective subtractive hybridization of cDNA produced from cultures of A. gaisen grown either in total darkness(More)
Kinematically redundant manipulators, by deenition, possess an innnite number of generalized inverse control strategies for solving the Jacobian equation. These control strategies are not, in general, repeatable in the sense that closed trajectories for the end eeector do not result in closed trajectories in the joint space. The Lie Bracket Condition (LBC)(More)