Automatic segment assembly in shield method using multiple imaging sensors

The shield method is one of subsurface excavation method in underground construction. It’s a fully mechanized construction method using shield machine. However, the process of segment assembly now mainly relies on manual work, controlling the assembly robots by experience. This work aims to aid the automation of precise movement control of the assembly robot, especially the movements of sliding, rotating, and deflecting directions. It proposes a new method using multiple imaging sensors to collect image information needed for automatic assembly of segments, and uses information extraction, size measurement and other real-time image processing to determine the spatial attitude of the three directions of the segments to be assembled. By Importing the data into an automation solution, the segments could move along the correct path. Experiments are conducted to test the performance and reliability of the proposed method in an actual underground working environment. The results are validated by successful bolting process in the actual subway construction, showing several different types of segments can move to the correct assembly position and the process is reproducible. Some disadvantages of the method are discussed, and suggestions for improvements are suggested. The proposed method has the potential to be adopted to enable the automation of segment assembly in shield method and may be applied to actual construction.