Abstract: In the garment industry, there are difficulties in designing a universal manipulator due to the large size span of the pieces. In order to address the requirement of grabbing pieces of different sizes during the garment production process, a 4-RRR quadrangular prism folding unit model is proposed based on the expandable mechanism, and its universal theory of single-degree-of-freedom expandability is explored. The corresponding manipulator mechanism is designed by adopting the 4-RRR quadrangular prism folding unit, and the kinematic characteristics analysis is carried out. Using the D-H parameter method, the kinematic equation is established and the kinematic solution of the mechanism is obtained. Through the ADAMS simulation of the manipulator mechanism, the reliability of the mathematical model is verified, and the folding ratio of the manipulator is also solved. Finally, the physical folding experiment was carried out. The results show that the manipulator designed by the 4-RRR quadrangular prism folding unit can meet the target requirements and has a large folding ratio.
Keywords: expandable mechanism; quadrangular prism unit; folding manipulator; single degree of freedom; kinematics