抄録
In the present paper, singularity analysis of a 3-URU non-overcontrained spherical parallel mechanism with three degrees of freedom has been theoretically discussed. Based on the screw and reciprocal screw of each connecting chain, condition for constraint singularity has been derived, and some concrete conditions have been presented. Deriving the velocity relationship between input and output based on the concept of reciprocal product, conditions for actuation singularity and reach limit singularity have been derived. Condition for local-mobility singularity has been also derived, and an example has been presented. Numerical calculation technique to accurately find these singular points in the workspace has been also discussed.
