Dynamics and chatter analysis in robotic milling

The industrial robot has been employed in the field of machining processes due to its high flexibility, while its applications are restricted by the structural disadvantages (i.e., poor stiffness and low positional accuracy). The robotic high flexibility is evidenced by the ability of reaching a specified position through various postures. Therefore it is important to identify the dynamic behaviours of a specific point at different postures. The frequency responses of the cutter tip of a robot are measured by separating the working area into several layers. The result shows that dynamic characteristics are dependent on posture. The critical depth of cut is ranged from 0.35 mm to 0.93 mm by taking an example of spindle speed 2,000 rpm. And the critical depth of cut when feeding in Y direction is much larger than the X direction.