A new approach to the classification of architecturally singular parallel manipulators

This is a new approach to the classification mentioned in the title. We prove that a complete classification is possible in a geometric way if we distinguish the cases whether the linear line complex spanned by the carrier lines of the legs is always singular or not. The proof is based on the result that 5-legged planar parallel manipulators of Stewart Gough type which belong in every possible configuration to a singular linear line complex must possess 4 collinear anchor points. Moreover we list all types of 5-legged planar parallel manipulators with this property.