Research On Trajectory Tracking Control Of Shield Machine During Tunneling Process

Shield tunneling method has been the main method in the underground tunnel construction.With the acceleration of urbanization and the social economy development,shield tunneling machines still have wide application market in China.However,due to the late import time of shield technology in China,a great deal of problems still need to be studied and solved urgently,especially in the aspect of automation control of the shield machines.The Designed Tunnel Axis(Abbreviated as DTA)is the reference axis in shield tunneling.Whether the actual tunneling axis of the shield machine can track DTA directly affects the quality of shield construction.At present,artificial methods are still used in the trajectory tracking control of shield machines.According to the deviation between the actual driving axis and DTA,the operators control the posture of the shield machine by experience so that the tracking of DTA is realized.Based on the above background,this thesis does some research on how to realize the automation tracking control in shield tunneling and acquires some achievements.The main contributions of this thesis are:1.Trajectory planningIf the deviation between the actual driving axis and the DTA is large,it is necessary to design the correction trajectory and take it as a part of the DTA to be the datum in shield tunneling.According to the characteristics of shield tunneling along the DTA,the position and posture of shield machines are classified,and trajectory planning characteristics are analyzed based on the specific deviation.Considering that the transition curve is the linear part of DTA,and the curvature radius of the transition curve varies uniformly,the trajectory is designed as the transition curve form with the constraint of the minimum turning radius of the shield machines.Under the security constraint in shield tunneling,an algorithm which can match the transition curve with the minimum number of straight lines is proposed to reduce the complexity of the curved construction in shield tunneling.2.The dynamic model establishingThe dynamic model of the shield machine is established by the the measured data-based method.First,the statistical analysis of the measured data is done and the characteristics of the shield tunneling motion are analyzed.Then,the input and output variables of dynamic model are selected and the T-S fuzzy model is selected as the form of shield machine dynamic model.The identification method of the T-S model is as follows:The fuzzy C-means clustering method is used to cluster the measured data and to identify the antecedent parameters of the T-S model with less number of sub-spaces;Then,the least squares method is used to realize the identification of the parameters of the T-S fuzzy model.3.The attitude fuzzy controller designingIf the deviation between the actual driving axis and the DTA is small,it is necessary to select a proper correction strategy to reduce the deviation.After deeply studying the operation strategy of artificial posture control methods of shield machine,the working principles of the attitude fuzzy controller are analyzed based on the fuzzy control theory.Adjusting the thrust system and hinged system of the shield machines are selected as the operation strategy of attitude control,and the input and output variables of the fuzzy controllers are selected.In view of all the possible deviations of the shield machines,49 fuzzy control rules are summarized according to the manual operation experiences.Then,the design of fuzzy controller is completed and a fuzzy control look-up table is calculated.At last,the validity of fuzzy controller is verified based on the measured data and the realization of the fuzzy controller on PLC is studied.Finally,the MATLAB simulation experiment of the designed fuzzy controller is carried out.