Precise vehicle positioning using integrated GNSS/low cost dead-reckoning sensors

点击翻译按钮获取中文摘要

The need for high accuracy vehicle positioning has accelerated over the past few years due to the increased demand for systems that provide improved safety and reliability. For example, car manufacturers are currently very interested in systems that can position vehicles to within a few centimetres. Initially, this information can be valuable for vehicle stability control systems and longer term it could provide a necessary component towards more automated vehicles. Current vehicle positioning systems rely on a combination of Global Navigation Satellite System (GNSS) technology (i.e. the Global Positioning System - GPS) with low cost dead-reckoning sensors, most typically an odometer, and these systems are aimed at providing metre-level accuracies. When moving from metres to centimetres, there are several significant challenges. One of the most critical is the potential for GPS outages in environments where there are blockages due to buildings, for example. In this case, continuous GPS tracking is not maintained, and the positioning algorithm has to be restarted after the outage such that it may take a minute or more to obtain centimetre accuracies again. In order to develop a system for precise vehicle positioning in harsh environments, GPS will be integrated with additional dead-reckoning sensors. The first phase will consist of investigating the fusion of low-cost miniature, self-contained, micro electro-mechanical systems (MEMS) sensors. There are various emerging low cost sensors based on MEMS technology that are currently being embedded into vehicles to support vehicle dynamics modelling. These sensors range from odometers to accelerometers. The second phase will be to investigate emerging high sensitivity GPS (HSGPS) signal tracking technology that allows measurements under degraded signal environments such as urban canyons and indoors. Currently this technology is used for metre-level work and it will be expanded to high accuracies through close association with the GPS manufacturer. New GPS signals, in addition to those being offered by the Europe's emerging GALILEO system, will also be investigated.