A Novel Delta-Like Parallel Robot with Three Translations and Two Pitch Rotations for Peg-in-Hole Assembly

Abstract This paper presents a novel 5-degree-of-freedom (5-DOF) Delta-like parallel robot named the Double-Pitch-Delta robot, which can output three translations and two pitch rotations for peg-in-hole assembly. First, the kinematic mechanism of the new robot is designed based on the DOF requirements. Second, the closed-form kinematic model of the Double-Pitch-Delta robot is established. Third, singularities of the Double-Pitch-Delta robot are identified based on screw theory, and its workspace with free singularities is quantitatively analyzed. At last, a physical prototype of the Double-Pitch-Delta robot is developed to verify the effectiveness of the designed mechanism and the established models. Compared with the existing 5-DOF parallel robots with two pitch rotations, the Double-Pitch-Delta robot has a simpler forward displacement model, larger workspace, and fewer singular loci. The Double-Pitch-Delta robot can be also extended as a 6-DOF hybrid robot with the full-cycle tool-axis rotation to satisfy more complex operations. With these benefits, the new robot has a promising prospect in assembly applications.