New Decoupled 2-Dof Parallel Mechanism with Fully Spherical Workspace

Abstract

Decoupled 2-dof spherical parallel mechanism is an important valued spherical parallel mechanism. It is one of the preferred solutions in the field of large-angle spherical workspaces. By studying the configuration of the exiting kinematic decoupled spherical parallel mechanism, it is found that the key issues that it cannot achieve a fully spherical workspace is that the output angle range of the “linear input – rotation output” kinematic chain cannot reach 180°. Based on the input and output characteristics of the double rocker mechanism, two new ideas for constructing the configuration of the “linear input – rotation output” kinematic chain are presented. The output angle range of the new “linear input – rotation output” kinematic chain can reach 180°. Based on the new design idea for “linear input – rotation output” kinematic chain, two new kinematic chains are designed: P5R and PRR. Based on the above kinematic chains, two 2-dof decoupled parallel mechanism with a fully spherical workspace are designed, i.e. RR&P5R parallel mechanism and RR&PRR parallel mechanism.