Using Direction Arbitary Projection To Unify The Coordinate Sysytems Of Operation Railway

In order to satisfy the projection deformation value should not be more than 10 mm/km in specification for survey engineering of high-speed railway, designers of railway line always divide the plane coordinate system of high-speed railway into several Gauss independent coordinate systems. The designed central line in the overlapping area of adjacent projection zone can be calculated by the design parameters of left or right projection zone. Because of the deformation of projection, the same designed central lines calculated by different projection zones have lateral deviations, if this problem can-not be handled well, it will reduce the regularity of track and bring hidden danger to the operation safety of high-speed railway.To eliminate the lateral deviations of the designed central line caused by the deformation of projection in the overlapping area of adjacent zone, this paper proposes a new method of using direction arbitrary projection to unify the coordinate systems. Firstly, the line control points can be projected into a same coordinate system by using direction arbitrary projection. Secondly, using the common points which are converted line control points, the conversion parameters which are from the Gauss independent coordinate system to direction arbitrary projection coordinate system, can be calculated by the total least squares(TLS). Based on the conversion parameters, points of intersection in the Gauss independent coordinate system can be converted into direction arbitrary projection coordinate system. Using the points of the intersection, new radius of the circular curve and new transition curve, the new parameters of horizontal curve and vertical curve can be obtained.The new line parameters, including deflection angle, radius of circular curve, transition curve and so on, will be different from the original designed parameters. To establish a function between of the line’s parameters and the vertical deviation can obtain the regularity function of 30 m and 300 m. According to calculate the differentiation of deflection angle, radius, length of transition curve in regularity function, it can be found that the new line parameters can-not reduce the original line regularity of track in theory. Finally, based on the engineering project, the coordinate transformation calculated by total least squares (TLS) can be finished by MATLAB, and the new horizontal and vertical parameters of railway can be obtained. To analyze the effect of the regularity of railway caused by the difference parameters, it can be concluded that difference of the line parameters have no effect on the regularity of the original railway, and the method that using direction arbitrary projection to unify the coordinate systems of operation railway is effective.The method that using direction arbitrary projection to unify the coordinate of operation railway can eliminate the lateral deviations which exist in the designed central line, unify the coordinate systems and the mileage systems, and increase the efficiency of track surveying. And it has high engineering practicability.