Orthogonal gough-stewart platforms with optimal fault tolerant manipulability

For any manipulator, fault tolerance is a desirable property. This paper shows that for any serial or parallel manipulator functioning about a single point in its workspace, the mean square of the relative manipulabilities over all possible failures, with a given number of links failing at a time, is always constant irrespective of the geometry of the manipulator. In this paper optimal fault tolerant manipulability is defined for parallel manipulators. This concept is applied to orthogonal Gough-Stewart platforms (OGSPs) to identify a class of symmetric OGSPs having optimal fault tolerant manipulability. As an example, an 8-strut OGSP having this property is described