  Various performance indices are used for the design of serial manipulators.
One method of optimization relies on the condition number of the Jacobian
matrix. The minimization of the condition number leads, under certain
conditions, to isotropic configurations, for which the roundoff-error
amplification is lowest. In this paper, the isotropy conditions, introduced
elsewhere, are the motivation behind the introduction of isotropic sets of
points. By connecting together these points, we define families of isotropic
manipulators. This paper is devoted to planar manipulators, the concepts being
currently extended to their spatial counterparts. Furthermore, only
manipulators with revolute joints are considered here.
