Abstract: During synchronous shield tunneling and segment assembly, substantial shield attitude fluctuations occur due to delays and inaccuracies in manually adjusting the thrust of individual propulsion cylinders. To address this, an automatic shield attitude control system based on thrust vector technology is proposed, eliminating the need for manual intervention. The authors develop and verify the proposed approach through systematic improvements in operational processes, intelligent control system design, equipment upgrades, and engineering validation. The following conclusions are drawn: (1) The propulsion system achieves good synchronization, though cylinder stroke utilization and manual assembly instability directly affect the efficiency of parallel operations. (2) The target pressure control accuracy for propulsion cylinders is within ±10%, and the propulsion speed reduction is controlled within 8 mm/min under parallel control, with the intelligent system responding effectively to required thrust adjustments. (3) The shield cutterhead′s attitude and the displacements of the thrust action point in horizontal and vertical directions exhibit time-symmetric behavior. Although the maximum instantaneous displacement due to cylinder retraction is 10 mm, the overall shield attitude is maintained within ±15 mm of the target. (4) Compared with traditional manual control, the integrated parallel control system for automatic shield tunneling and segment assembly achieves higher precision in thrust vector control, propulsion speed regulation, and attitude adjustment, offering superior stability during continuous excavation.

Key words: shield machine, automatic shield tunneling, segment assembly, parallel control