Kinematic Modelling and Workspace Prediction of a Hybrid Kinematic Machining Unit Integrating Redundantly Actuated Parallel Manipulator

To meet the increasing requirements for high-performance machine tools in manufacturing industry, a 5-axis hybrid kinematic machining unit (HKMU) is proposed with a topology of 2UPR&1RPS&1RPU-XY. Firstly, the inverse/forward position of the HKMU is analyzed by using the closed-loop vector method. Secondly, based on the position analysis, a 3-axis and a 5-axis reachable workspace are defined to demonstrate the motion capabilities of the proposed HKMU. And a ‘hierarchical’ searching algorithm is proposed to calculate the above two types of reachable workspace. Finally, the relationship between dimensional parameters and reachable workspace is graphically revealed by using an illustrative example of the proposed HKMU.