Dynamic analysis of the 2-DOF planar parallel manipulator of a heavy duty hybrid machine tool

This paper focuses on the dynamic characteristics of the two degree-of-freedom (DOF) planar parallel manipulator of a heavy duty hybrid machine tool. The Newton-Euler approach is employed to derive the inverse dynamic equation of the parallel manipulator. According to the motion planning of the cutting tool, dynamic simulation without cutting force is performed, and the ratio of the masses of counterweights to that of moving parts (not including the counterweight) is optimized. It demonstrates that the manipulator which is designed with over constraint can improve the dynamic behaviour. Furthermore, the cutting force model for face milling is introduced and the dynamic simulation with the dynamic cutting force is carried out. Simulation shows that the oscillation of cutting force is one cause of the vibration of the machine tool in the milling process. In the detailed design, some modification in the structure of the machine tool is made to suppress the vibration.