Research On The Key Techniques Of The Guidance System Of Double Shield Universal Compact TBM

During the underground subway and tunnel construction process,Double Shield Universal Compact TBM(tunnel boring machine),which can solve small turning radius,high rock strength and complex rock properties tunnel and so on,is to become the best choice on tunneling for hard rock.For Double Shield Universal Compact TBM,real-time position measurement of the front shield is a difficult problem needed to be urgently solved by automatically guide system of TBM,especially the real-time and precise positioning of the center of the front shield body.Around this requirement,in this paper,a combined measurement system based on laser target and monocular vision is designed,with the total station,which is composed of guidance system of Double Shield Universal Compact TBM.System measuring principle and calibration method is researched.Finally,an accuracy verification experimental system is set up,the results showed that measurement accuracy of guidance system is better than 8mm within 35 m × 3m × 2m measuring space,the guidance system can satisfy precision measurement requirements for pose guide of Double Shield Universal Compact TBM.The main research work of this paper are summarized as follows:1.Analysis research status of guidance system of TBM and lack applied for Double Shield Universal Compact TBM pose measurement,combined with the advantages of monocular vision in relative position and orientation measurement field,guidance system of Double Shield Universal Compact TBM is designed with the combination of monocular vision and laser target.2.According to the overall scheme design of the guidance system,the selection of the optical characteristic points and design of spatial structure is completed.Based on the ARM-Linux embedded system,intelligent vision sensor which integrates image acquisition and processing,pose solver and data communications.Based on intelligent vision sensor,connected domain is selected for labeling features of the spot,the center of the optical feature points is extracted by square weighted centroid method.Through the design of spatial distribution model,the optical feature points is matched.Based on optical feature points,combination of the nonlinear iterative method and the linear method is used to solve the optimal relative pose estimation between front shield and back shield.the measurement principle of laser target is analysis.The mathematical model of the guidance system is constructed,location of the center of the front shield body for Double Shield Universal Compact TBM can be figured out.3.Camera internal parameters of the intelligent vision sensor is completed calibration by building three-dimensional control field.The calibration of relative position between the optical feature points and center of front shield completed by means of the total station.Based on reverse solution of combined measurement principle of guidance system,accurate calibration of the relative position relationship between intelligent vision sensor and laser target completed.4.Simulation of the guidance system is verified using MATLAB.Experimental system that can simulate the pose change of double shield universal compact TBM is set up,and the accuracy of the measurement system is verified by the total station.