Design of a Novel 4-DOF Kinematotropic Hybrid Parallel Manipulator

This paper presents a novel 4-DOF kinematotropic hybrid parallel manipulator. The topological structure allows for the realization of two translatory and two rotary output motions. Both the translations and rotations take place only in two orthogonal axes. The rotations are designed to possess the kinematotropic property, namely the output mobility of the manipulator can be changed while the topological structure remains invariable. In the process of the topological synthesis, two types of topological arrangements of the kinematotropic hybrid parallel manipulators are developed in the form of multiply moving platforms and subchains based on displacement group theory and mathematical logic. Kinematic modeling of the most feasible kinematotropic hybrid parallel manipulator is performed by obtaining its kinematic forward and inverse solutions and velocities. Suitable drive methods are also defined. At last, a prototype of the analyzed kinematotropic hybrid parallel manipulator is built to evaluate the feasibility of the developed design method, validate the kinematic modeling, and establish the manipulator’s kinematotropic properties.