A new isotropic and decoupled 6-DoF parallel manipulator

The paper discusses the concepts of isotropy and decoupling in n-DoF (degrees of freedom) manipulators: isotropy means that its kinetostatic properties are identical in all directions, while decoupling means that each DoF of the end effector is controlled by a single actuator. The role of different Jacobian matrices in the isotropy, decoupling and in the general mobility analysis of the manipulators is revised. These concepts are applied to a Gough–Stewart platform showing that it may be isotropic, but not decoupled. A modification of its leg structure is suggested to develop some new 6-DoF PKMs (parallel kinematic machine) decoupled and isotropic in the considered configuration. An introduction to the mobility analysis of serial and parallel manipulators is also presented.