The Key Technology Of Precise Measurement Research Has Both Lines

As railway and maintenance to railway keep rising, the measurement on railways are supposed to be improved to a higher level.For existing lines with incompleted measurement network, establishing an accurate one turns to be the right practice in order to achieve the accurate measurement. Comparing involved technology at home and abroad, the paper for the first time conducted a systematical research on setting up an accurate measurement network for existing railway lines, which laid a theoretical foundation for accurate measurement on these tracks. The main works of this paper are as follows:(1) According to the existing existing accurate measurement system, based on the comparision of those who have accurate control network and those who haven’t, the paper describes the major problem to the incompleted network lines in mathmatics, which simplified the engineering problem into a mathmatics one with full inllustration on all key parameters, setting a correct direction for the sbusequent research.(2)An inversion model on foundation piles with a derivation process was proposed. Taking the3D coordinates of the piles and the deflection angle as the independent variables.It starts from an assumption that they were already figured out. Based on the understanding of function approximation, the conclusion that the sum of all the orthogonal distances should come to minimal optimization was reduced. According to the characteristics of the design of railway lines, the paper conducted three models for the three types of railway track by means of establishing independent coordinate systems. As a result of the analysis all above, the inversion model was arrived at a conclusion.(3) Successfully calculated the inversion model by the use of multi-variable optimization methods. DFP method helped to figure out the objective function while on-or-back algorithm gave an interval of the step which was finally determined by golden section method. DFP takes the advantage of global optimization as well as the great convergence rate.(4) Simulation on the conducted model was presented. A reasonable simulation project was designed from selecting an appropriate simulation software to deciding detailed simulation situations. The absolutely coordinate of foundation piles and the offset on each position were finally figured out. The relative position between the real track and the designed one was demonstrated by image. The results showed that the method presented can well meet the requirements of the accurate measurement.