The kinematotropic 3-CPU parallel robot: analysis of mobility and reconfigurability aspects

This paper investigates the mobility analysis of a 3-CPU parallel machine, aiming at checking the possibility to perform both pure rotational and pure translational motions. Machine kinematics is formalized by taking advantage of algebraic geometry principles that allow extracting the necessary constraint equations in form of polynomial ideals. The analysis of the sub-ideals deriving from the decomposition of the starting constraint equations yields the conclusion that several kinds of motion are actually achievable by the same 3-CPU architecture. Among them, pure rotational and pure translational mobilities are present. Finally, the existence of machine configurations allowing the transition between such modes is proved and the related poses are explicitly worked out.