Abstract: The new generation of aerospace vehicles use a large number of integrated complex components as their main structure. Therefore, the traditional machine tools are difficult to meet the high machining quality, high efficiency, and high flexibility requirements of complex components. Although faced with the bottleneck of low precision and poor rigidity of the robot, the equipment of machining system, based on industrial robot is an effective new way to solve this problem. In order to improve the machining accuracy of industrial robot, a robot milling system based on Siemens 840Dsl CNC system is built. By using the joint-Cartesian space combined accuracy compensation method, the repetitive positioning accuracy of the robot is increased by 74.68% from 0.154 mm to 0.039 mm, the absolute positioning accuracy increased by 88.06% from 1.307 mm to 0.156 mm, and the trajectory accuracy increased by 86.55% from 1.346 mm to 0.181 mm. The on-line real-time compensation of positions and trajectories is realized. The milling experimental results show that the milling accuracy of the composite cabin reaches 0.22 mm, and the surface roughness is better than Ra4.8. Thus, robot milling system meets the requirements of aerospace parts processing.

Key words: robot milling, high precision machining, accuracy compensation, error similarity, trajectory accuracy