Mechanism Design and Inverse Kinematics of a 6-DOF Hybrid Robot with Two Parallel Modules

This article proposes a novel 6-DOF hybrid robot that includes two parallel modules positioned above each other. The upper module is a 4-DOF Delta-type mechanism, and the lower one is a 2-DOF mechanism with a circular rail. The suggested design provides the robot with advanced kinematic capabilities that cannot be achieved by the separate use of upper or lower modules. The article considers an algorithm of the inverse kinematics, which allows computing displacements in the actuated joints for the specified relative configuration of the modules. During the first stage of the algorithm, we determine configurations of the modules relative to the fixed base. Next, we solve the inverse kinematics for each module individually. The suggested algorithm is demonstrated with a numerical example, where we set a motion trajectory of the upper module relative to the lower one.