3D-Gleiserfassung mit einem Multisensorsystem und linearen Filterverfahren

Abstract

Methods for surveying and monitoring railway tracks have to meet high requirements, especially for the construction of high-speed railway lines. A new surveying and evaluation concept has been developed mainly for economic reasons. This new concept aims at determining the following parameters for the track system: three-dimensional position of the centre of the track or one rail, the gauge and the banking of the track. The measurement system consists of a three-dimensional positioning unit and electronic sensors which are connected to a process computer. All the components are installed on a lightweight carriage which can be moved on the track. The concept is automated to a large extent by a computer which monitors and regulates the process. Terrestrial polar measurement systems can be used as well as real-time kinematic GPS. The optimum measurement distance is estimated using Shannon's theorem. The evaluation uses algorithms which can be employed optionally during the measurement process (ongoing evaluation) or afterwards (post facto evaluation). For the ongoing evaluations, the use of an adaptive Kalman filter is generally recommended, and for the post facto evaluations the Wiener filter, an adapted collocation method. These methods can be modified and adapted. New software was developed for this purpose. Analysis of series of measurements has shown that a high level of precision can be achieved. The concept can be employed to monitor existing railway tracks and to survey the rail during tracklaying. There is no need to close the line during the survey. By comparison with conventional methods, a threefold to fourfold increase in performance can be expected. The modular structure of the system facilitates further development and refinement.