Intelligent verticality-adjustment method of end-effector in aeronautical drilling robot

Based on the requirement of robotic drilling for aircraft fuselage, a novel verticality adjustment method of drill bit in aeronautical drilling robot system was proposed, which is composed of surface-normal measurement and adjustment of drill bit-s attitude. Three laser range sensors were used in surface-normal measurement to measure the distances between sensors and three measurement positions around the drilling point. Thus the normal vector can be calculated from the cross product of any two vectors that are tangent to the surface at the drilling point. Meanwhile, the angle between normal vector and drill bit was obtained, which was fed back to the control system. Finally, the attitude of drill bit was adjusted using the binary angular adjustment mechanism (BAAM) to correct drill bit in line with the normal vector, which ensures to drill along the normal direction of drilling point. The high-accuracy, high-efficiency and practicability of the verticality adjustment method were tested by the experiments conducted on the aeronautical drilling robot, which meet the requirements of the auto-drilling for aircraft manufacturing.