A new family of reconfigurable parallel mechanisms with diamond kinematotropic chain

This paper focuses on a diamond kinematotropic chain which is integrated in the construction of a new family of reconfigurable parallel mechanisms. The branch transition of the planar diamond kinematotropic chain is analyzed and the equivalent kinematic joints corresponding to each motion branch are identified. Kinematic limbs that can provide a constraint force and a constraint couple are enumerated based on screw theory. Sixteen reconfigurable limbs which are capable of decoupling the constraint force and the constraint couple in the reconfigured configurations are constructed by integrating the diamond kinematotropic chain. A family of reconfigurable parallel mechanisms having three identical kinematic limbs is structured by connecting the platform to the base with reconfigurable limbs. The platform of each reconfigurable parallel mechanism has ability to perform variable motion modes such as 3 T, 2T1R, 2R1T and 3R. One of the reconfigurable parallel mechanisms is sketched as example and the actuation scheme for the mechanisms in this family is discussed.