A novel approach for the acquisition of vibration signals of the end effector in robotic drilling

In terms of flexibility and versatility, the robotic drilling seems a promising solution for the large quantities of holes of aircraft structural parts. However, the low stiffness of the robots may induce chatter vibration in the drilling process, which results in poor surface quality and low machining productivity. Therefore, it is of vital importance to detect and prevent this undesirable instability. In this paper, an approach is presented for the acquisition of vibration signals of the end effector in robotic drilling. To begin with, the robotic drilling system is presented. Then the motion of the end effector is decomposed into the translation motion along the spindle and the plane motion perpendicular to the spindle. With the aid of the rigid body kinematics, the vibration signals of the end effector can be obtained through two triaxial accelerometers with the proposed method. Finally, the effects of accelerometer location and orientation errors are analyzed. The simulation results show that the measurement results are sensitive to both location and orientation errors.