Integrated robotic machining error compensation for intersecting hole of large spherical shells

The flange holes on large aluminum ball shells are processed on-site by industrial robots, and the flange holes need to ensure the hole position and axial accuracy requirements at the same time, but it is challenging to ensure that these two indexes meet the requirements at the same time due to the lower machining accuracy of the industrial robots. For this reason, the paper proposes a robot integrated error compensation method for hole position and axial deviation constraints. First, the robot machining path is generated, and the cutting allowance and hole inner wall measurement strategy are determined by running the machining path empty before machining. Integrated error compensation is then introduced and a new hole surface is constructed as a mirror surface under its conditions. The tool path is adjusted according to the mirror compensation principle to ensure consistency between the machined and target holes. The reconstructed target hole surface satisfies the integrated error constraints and realizes the balanced constraints of positional and axial tolerances, making full use of both tolerances. Finally, the method's effectiveness has been verified in a large-scale work. Experimental results show that hole position error is reduced from uncompensated (1.03, - 0.51) mm to compensated (0.25, - 0.005) mm, and axial error from uncompensated 22.32 mm to compensated 1.39 mm.