Mobility analysis of certain geometries of a RPSPR kinematic chain

This paper presents the mobility analysis and type identification of certain geometries of a RPSPR kinematic chain. The objective of the analysis is to derive conditions for detecting the presence of crank at any one of the revolute pairs. The mobility conditions are expressed in analytic (in certain cases) and geometric forms in terms of the link parameters. The conditions have very interesting geometric interpretations which have been clearly brought out. Based on the geometric conditions, in certain cases, simple sufficient conditions of rotatability have been derived.