Workspace Analysis of a 5-Axis Parallel Kinematic Machine Tool with 3-RRS Parallel Manipulator

Parallel Kinematic Machine (PKM) because of its interesting alternative designs and versatility has gained a lot of interest in many industrial applications and in production lines especially in high-speed machining applications since they offer a number of advantages over the serial manipulators like better accuracy, higher structural rigidity, higher agility and improved dynamic characteristics. Conventional PKMs are designed to have 3-Degree of Freedom(3-DoF) movement of the moving platform; however, in this work, two additional DoF have been incorporated in the form of movement of the base in X and Y directions. The configuration of the 3-DoF parallel manipulator (PM) used here is 3-RRS with 1T2R type of motion of moving platform. This paper presents a type of 5-axis PKM tool architecture on which the 3-RRS PM having 3-DoF motion slides on the frame structure of the machine tool along X-direction and Y-direction providing extra 2-DoF. Complete position level kinematic analysis is carried out and the workspace analysis of this mechanism is proposed in this paper. This workspace analysis shows the reachable work volume of the end-effector and enables to know the complete reach of the tool required for the complex industrial applications and machining operations. A quantitative improvement in reachable work volume over conventional 3-DoF PKM is presented.