Research On The Construction Method Of The Digital Track Map Data

Digital track map is an important foundation of train positioning by satellite navigation. In the process of building digital track map data, we need to perform specific operations on the line data obtained by surveying, for example, reduction, interpolation, smoothing, calculating the milestones and so on. Since the large amount of surveying data, we also need to standardize data version management.Processing staffs use common commercial software for digital track map data building at present. Different processing staffs use different methods and tools to process map data, the methods are lack of systematic. In particular, in terms of integration of multi-track line data and smoothness checking, works are often achieved manually, which brings a huge amount of work to processing staffs, and can not ensure accurate and reliable of data. So we must establish a convenient and fast method for generating digital track map.The outline of this thesis is described as follows:(1) A software is developed for editing map data. Considered the conditions of surveying, software operation, laptop battery life and other factors, the software implements a customized map display user-control that optimized to display millions of GPS points. More than thirty kinds of commonly used line editing functions is achieved, witch make the software as integrated dedicated software of digital track map.(2) A kind of exchangeable digital track map data format based on text is constructed, using multiple kinds of files in the same folder to storage orbital position data, topology and key attribute information and so on. According to the characteristics of the track map data to build, we using the "lock-modify-unlock" model based on SVN to share data and manage versions.(3) Amplitude spectrum is analyzed by short-time Fourier transform (STFT) to check the smoothness of line data, and integrated a bad segment positioning function in the software, which greatly reduced the workload of the line inspection and confirmation.(4) A method is developed with no model to generate track map automatically from multiple tracks of survey data. The method does not need to distinguish between orbital shapes, and work without setting algorithm parameters. Meanwhile, the algorithm is able to control the spacing between two adjacent data points, realize the resampling of the line. This algorithm has proven robustness in the interference conditions by experiments, and can effectively increase data smoothness.In this thesis, we use train positioning logs of Han-Yi (Wuhan to Yichang) high-speed railway, surveying data from Lhasa station to Lhasa west station, Shouyang Shanxi Province and Jincheng train GPS positioning data to test the algorithm. And we use the surveying data of Xiantaoxi station to test the map editing software. The tests proved the map editing software can greatly reduce the workload of generating digital track map.