Large Fixture Calibration Method Based on Point Cloud Scanning for Robotic Drilling

The rocket fuel tank requires the splicing of multiple sub-parts, which is difficult to be processed in an integrated manner. Among them, the short shell parts of the storage tank play a linking role and need to be drilled on the surface. Due to the large size of the tooling of the parts, there are problems such as large installation and positioning errors and low precision of robot automatic drilling. Therefore, a robot automatic hole making calibration method is proposed to solve the current problems. In order to achieve automated control, a large-scale robot automatic drilling system must have large-scale flexible tooling, control algorithms, human-computer interaction interfaces, execution units, and integrated tool rooms. It is essential to build effective calibration procedures as a foundation for this automation. The calibration plane is fitted, positioned, and calibrated using the point cloud scanning method. Subsequently, the hand-eye calibration method is employed to establish the relationship between the coordinate systems. Using this approach, the calibration process is ultimately finished, resulting in the successful implementation of automated drilling. The experimental findings demonstrate that, in the designated quadrant, the drilling rate of the robot can achieve 5 holes per minute. Furthermore, the average variance of the hole position is below 0.2mm, and the highest error is 0.5mm. These results align with the requirements of practical production.