Position and Attitude Precision Analysis of Segment Erector of Shield Tunneling Machine

Focusing on a segment erector of a shield tunneling machine developed with 6 degrees of freedom and controlled by electro-hydraulic proportional systems, kinematics for the segment erection process is presented. The perturbation method in error analysis is introduced to establish the position and attitude error model, considering a number of factors such as hydraulic drive and control accuracy, tolerance in manufacturing and assembly. Dynamic simulations are carried out to obtain the controlling precision of the electro-hydraulic drive systems. Formulas for calculating the position and attitude error of the grip hand of the segment erector are derived. The calculation results verify the practicality and effectiveness of error analysis, providing a foundation for practical designing, manufacturing and assembling of the segment erecting mechanism.