Kinematic and Structural Design Assessment of Fault-Tolerant Manipulators

Abstract

ABSTRACTFault tolerance technology promises higher system reliability even under unexpected component failure. Such capability is attained by developing a structural system design that can deliver fault tolerance, and by designing controllers that can take advantage of the fault-tolerant structure. This paper reviews fault-tolerant design issues from a kinematic and structural viewpoint. This is accomplished by studying the kinematic design of a fault-tolerant robotic system at four levels: (1) Joint level (Single and dual actuators); (2) Link level (Serial and parallel modules); (3) Sub-system level (Non-redundant and redundant manipulators); (4) System level (Multiple cooperating manipulators). This work addresses the four levels from a structural design viewpoint. A measure is developed to determine the relative fault-tolerant capacity gained from one manipulator to another. Other criteria are also reviewed in evaluating various manipulators as design alternatives in an effort to identify the most effi...