The Kinematics Analysis of a Novel 5-DOF Series-Parallel Machine Tool and Study on Its NC Architecture

The available workspace of parallel kinematics machine tool (PKM) is always very small, which is a common problem existing in PKM. In this paper, by making full use of the advantages of the series machine tool and PKM, a novel 5-DOF series-parallel machine tool has been proposed. The parallel mechanism of the series-parallel machine tool is a kind of 3-HSS mechanism with 3-DOF. The three ballscrews of the parallel mechanism are set horizontally. The series mechanism of the series-parallel machine tool, which is a turning mechanism with 2-DOF, is installed on the mobile platform of the parallel mechanism. The series-parallel machine tool has many advantages, such as easy building of the moving model, easy solving of direct and inverse kinematics, larger workspace in horizon direction, simple structure, easy controlling and so on. This paper mainly studies on its kinematics analysis and sets up the NC system with open modular architecture according to characteristics of the serial-parallel machine tool. Based on these, the prototype of the serial-parallel machine tool proposed in this paper has been manufactured. The correct tool trajectories have been achieved through the on-line manufacturing experiment, which verifies the reasonableness of the structure and the correctness of the NC system.