The study of drilling and countersink technology in robot drilling end-effector

Aiming at the drilling verticality in aircraft assembly, this paper presents a design method of a Double-Eccentricdisc Normal-Adjustment (DENA) mechanism; it can adjust the two rotational degrees of freedom by the interaction of two eccentric discs, and make the drill axis coincide with the normal direction of the drilling point. This method ensures that the position of the drill vertex can be kept static during the attitude adjustment process. In addition, it can avoid position compensation and secondary positioning, and then improve the drilling efficiency. Using pressure sensor, the robot can control the countersink depth by detecting the states of the drill and the pressing force of the cylinder. It can eliminate the influence of the deformation under the compression to the countersink depth precision and make the countersink precision accuracy within 0.05mm. Finally, the experimental results are addressed to verify the rationality of DENA mechanism and the feasibility of using pressure sensor to control the countersink depth.