Evaluation of GNSS receiver clock drift predictability in urban scenarios based on vehicle dead reckoning sensor data

摘要

In the past few years advanced driver assistance systems (ADAS) have been in focus of many research projects and development efforts of car manufacturers. Aiming on the capability of autonomous driving, positioning plays one major role. While precision and accuracy of uncoupled or loosely-coupled single frequency GPS navigation satisfies the requirements of route guidance, future ADAS will be more demanding towards availability, accuracy and integrity. The Institute of Flight Guidance (IFF) is currently involved in research projects evaluating the performance of unaided traditional GNSS receivers coupled with vehicle sensor measurements such as odometers in a tightlycoupled architecture as shown at the ION GNSS 2011([1]). Besides these involvements the IFF has developed a general purpose software-based GNSS receiver allowing full access to signal processing routines which has been already used to evaluate deep-coupled approaches as shown for example at the ION ITM 2013([2]). The vehicle state estimation of the tightly-coupled navigation is often derogated by GNSS signal shadowing and reflections due to buildings or plants, especially in urban scenarios. Moving a receiver under these conditions, the positioning solution can suffer from the low number of received signals, from frequent changes of the received constellation and from measurements affected by multipath. Even measurement datas without the minimum number of four signals can occur, which is required for a valid position.