On Intelligent Shield Guidance System

In order to alleviate the traffic congestion caused by the growth of urban population,many cities have begun to build large-scale subway.The extensive use of shield method in tunnel construction has promoted the development of shield measurement technology.In order to guide the measurement of high precision,high frequency and automation requirements,shield guidance system,shield tail gap measurement system,segment automatic selection system supporting the measurement system have been born,full participation in guiding shield tunnel construction.This paper follows the process of shield method,and carries on systematic research on the measurement work of each stage.(1)A continuous calculation model of shield attitude based on travel is constructed.On the basis of the laser target guidance system,the continuous shield attitude calculation is carried out based on the end face of the segment,combined with the gyro-guided system algorithm and the real-time propulsion cylinder stroke data.(2)A rigorous calculation model for measuring the tail gap is proposed.Through the study of the existing measuring range tail shield measurement system,according to the actual conditions introduced into the assembly machine stroke,through the three-dimensional geometric calculation of the measurement of the end of the shield tail gap to the end of the tube,using more in line with the actual construction workers The elliptical fitting method is used instead of the circular fitting method to calculate the shield tail gap.The simulation results show that the improved strict algorithm model is superior to the existing simple algorithm.(3)Design an adaptive segment selection algorithm based on three-axis fitting.Based on the analysis of tunnel construction technology,the principle of segment selection based on three-axis fitting of tunnel design axis,shield tunneling axis and segment assembly axis is proposed.Under the guidance of this principle,the factors influencing the selection are analyzed,and the optimal selection function composed of shield tail gap,cylinder stroke and segmental deviation is designed under the condition of assembling and disabling the point constraint.Assigned to determine the final selection of typesetting program,and in Ningbo,the actual use of a subway site to achieve better results.(4)The method of segmentation is given under the condition of shield tail gap,cylinder run length difference and deviation condition constraint.By studying the defects of the existing layout prediction model and the correction curve model,the numerical simulation and calculation of the whole process of shield construction are carried out by the interaction calculation between the continuous guidance algorithm and the automatic segmentation algorithm.The optimal shield tunneling path,get shield tail gap,cylinder stroke is poor and segmental deviation constraints under the conditions of the layout prediction program.