Vibration analysis and suppression in robotic boring process

• We construct a robotic boring system and analyze its characteristics.
• The mechanism of the vibration in robotic boring process is analyzed.
• The tool path that affects the final contour of the hole to be bored is studied.
• We propose a novel method to suppress the vibration of the robot.

The industrial robot, due to its flexibility, is considered as a promising option to accomplish the fine boring work of the aircraft intersection holes. However, the robot has a relatively low stiffness and is easily subjected to chatter vibration in the boring process, resulting in difficulty in guaranteeing the machining quality. In this article, the mechanism of the vibration in the robotic boring process is analyzed, and a novel vibration suppression method based on the pressure foot is proposed. First, a robotic boring system is presented. Based on its cutting characteristics and stiffness characteristics, the mechanism of the vibration is analyzed, followed by the study of the tool path during the boring operation. It is found that in the robotic boring process it is the robot itself vibrates rather than the boring bar, which usually vibrates in the traditional CNC machine tools. And the type of the vibration is found to be a forced vibration with a displacement feedback. Furthermore, a novel method making use of the pressure foot is proposed to suppress the vibration of the robot. Finally, large numbers of boring experiments have been conducted and the results verify the correctness of the vibration mechanism and the effectiveness of the vibration suppression method.