Kinematic analysis and optimization of a new three degree-of-freedom spatial parallel manipulator

A study of the kinematic characteristics of a three degree-of-freedom (dof) parallel mechanism is presented The architecture of the mechanism is compr ised of a mobile platform attached to a base through three identical prisma tic-revolute-spherical jointed serial linkages. The prismatic joints are co nsidered to be actuated These prismatic actuators lie on a common plane and have radial directions of action. The mechanism's inverse displacement sol ution is obtained. Since the mechanism has only 3 dof, constraint equations describing the inter-relationship between the six motion coordinates are d erived. These constraints allow the definition of parasitic motions, i.e., motions in the three unspecified motion coordinates. Architecture optimizat ion of the device is undertaken demonstrating that specific values of desig n variables allow minimization of parasitic motion. [S1050-0472(00)00101-X] .