The key aim of this research is to contribute to the development of a robust and reliable navigation system in order to support the positioning requirements of advanced transport telematics (ATT) services. This is achieved through the development of high integrity map matching algorithms. In the last two decades, satellite navigation technology, especially the Global Positioning System (GPS), has established itself as a major positioning technology for land vehicle navigation. Deduced Reckoning (DR) sensors, which consist of an odometer and a gyroscope, are commonly used to bridge any gaps in GPS positioning. However, DR sensor positioning errors can grow rapidly if not controlled by another sensor or system such as GPS. Digital road maps are used for spatial reference of the vehicle location via a process known as map matching. Map matching algorithms use inputs generated from positioning technologies and supplement this with data from a high resolution digital road network map to provide an enhanced positioning output. Existing map matching algorithms have weaknesses which decrease their capability to support many ATT services. Three high integrity map matching algorithms are developed in this research. They are the improved topological, probabilistic, and fuzzy logic map matching algorithms. These algorithms are successfully implemented, tested and validated using real field test data. A reference (truth) vehicle trajectory, as determined by high accuracy GPS carrier phase positioning, is used to validate the algorithms. The integrity (level of confidence) of the algorithms is analysed by taking into account the uncertainty associated with the map-matched location and the error sources associated with the navigation system and the digital map. The effects of navigation systems and digital map quality on the performance of map matching algorithms are also investigated for suburban and urban road networks. The results suggest that all three map matching algorithms developed in the course of this research have the potential to support the navigation function of a wide range of ATT services. However, of the three, the fuzzy logic map matching algorithm offers the highest performance, both in terms of link identification and location determination.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:484743 |
| Date | January 2007 |
| Creators | Quddus, Mohammed A. |
| Contributors | Noland, Robert ; Ochieng, Washington |
| Publisher | Imperial College London |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://hdl.handle.net/10044/1/1284 |
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