Research On The Identification Technologies Of Optimal Alignment Key Parameter Applied To Railway Plane Curve

With the rapid development of railway construction,especially the completion and operation of the high-speed railway network,railway maintenance problems have become increasingly prominent,one of the key problems to guarantee that the track has high smoothness of the running surface.At present,track irregularities survey and control in China is mainly based on the results of absolute survey,but there is serious contradiction between the low efficiency,the poor environmental adaptability of the technology and the short skylight in the railway.This paper compares the advantages and disadvantages of the coordinate method,involute method and direct railroad tracks adjustment technology based relative measurement method,and the field test was carried out by direct railroad tracks adjustment technology based relative measurement method.The advantages and disadvantages of this technology are discussed through the analysis of experimental results,and the corresponding improvement measures are put forward.As the following:(1)Direct railroad tracks adjustment technology based relative measurement method makes track smoothness as control target and can calculate ajustment amount in the picture to guide precision adjustment of the track irregularity.Because of avoiding the measurement of the external geometric parameters,the measurement efficiency is high and the environment adaptability is good,and it use the internal geometric parameters to control the internal geometric parameters,so the value of the transmission is more reliable.However,the adjustment calculation of the technology is based on the deviation between the design value and the measured value and the adjustment amount of the plan is not the smallest when the track is deformed.In addition,when the deviation between the design value and the measured value exceeds the maximum adjusted amount of the fastening system,the control methods mentioned above also do not completely smooth track.(2)When we are adjusting the railway route to guarantee the better smoothness,it is essential to seek for the optimal alignment of measured curve with the purpose of minimum amount of adjustment.Based on this background,a new key parameters of plane curve identification method based on the superelevation data of relative measurement and the improved Hough Transform is proposed.After robust estimation and sliding average,four feature points(ZH point?HY point?YH point?HZ point)of plane curve's optimal alignment can quickly and accurately be identified and,on which the circular radius of curve was identified according to versine at the range between identified point of spiral to curve and point of curve to spiral.After MATLAB simulation and example calculation,it is proved that the identification method can accurately,quickly and automatically identify the location of the four major feature point of the optimal alignment and giving the curve radius of the measured circle curve?(3)In order to make an evaluation of the identification accuracy of the feature point identification algorithm and determine which type of line needs to be adjusted according to the optimal alignment when we are adjusting the railway route,This paper chooses the representative versine of high speed railway as the research object and set up an versine deviation model between optimal alignment and measured route,puting forward the plane curve feature point offset receptive region(allowed maximum offset amount of the feature points)theor based on the measured versine smoothness judgment conditions unchanged(not exceeding).The research results show: by comparing feature point identification error with the acceptance region of the feature points,the accuracy of feature points identification can be judged.By comparing whether the deviation between the position of the feature points of the measured rotue and the position of the feature points of the design route is more than the feature points offset receptive region,we can judge whether to adjust track smoothness according to optimal alignment.In addition,the theory can also be transplanted to the common speed railway,fast railway,and is also a reference value for the evaluation of the feature point identification accuracy based on absolute measurement data.(4)According to the above theory and algorithm,the plane curve optimization route key parameter identification software was developed.By importing the relative measurement data,the key parameters of the plane alignment(ZH,HY,YH,HZ and the radius of circular curve R)can be identified,and a decision(whether to Adjust Track accroding to optimal alignment of measured route)is made.The algorithm,theory,software proposed in this paper has a favorable application foreground in fine adjustment of track,maintenance operation in skylight period,etc.