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Abstract
To address the navigation and positioning demands for military, marine, surveying, mapping, civil construction and many other uses, a number of innovative technologies have been developed to suit different environments, including technologies based on global navigation satellite system (GNSS), inertial navigation system (INS), terrestrial ranging, vision-based navigation, WIFI signals and others. The different characteristics of these individual systems result in a number of challenges for successful integration. One of the most challenging issues is the fault detection and exclusion (FDE) procedure used within integrated multi-sensor navigation systems. The primary objective of this thesis is to investigate from a geometrical perspective the benefits of integrating multiple sensors to system stability and reliability. Issues such as separability analysis of FDE are studied and applied to GNSS/INS, GNSS/Locata/INS, and GNSS/WIFI/INS integration systems. The major contributions of this research are:
a) A theoretical extension of the separability analysis of the data-snooping FDE method. The outlier (fault) detection test with two alternative hypotheses has been extended to handle multiple alternative hypotheses. The geometrical effects that cause missed detection and wrong exclusion were studied. A more accurate and reliable estimation of the minimal detectable bias (MDB) has been proposed so as to improve the success rate of the outlier detection procedure. Performance studies were conduct using a single-epoch GPS point positioning scenario.
b) An optimal receiver autonomous integrity monitoring (RAIM)-based FDE method was applied to GPS. It has been found that the probabilities of committing missed detection and wrong exclusion can be theoretically estimated to aiding in deciding whether or not the faulty pseudorange data can be correctly identified.
c) The FDE performance of loosely and tightly coupled GPS/INS integration system for land vehicle navigation was investigated and evaluated using some road tests.
d) Different integration architectures for GPS/Locata/INS integrated system have been investigated and compared with respect to navigation accuracy, reliability and integrity. The influence of LocataNet configuration on the performance of Locata-aided navigation systems was investigated.
e) A GPS/WIFI/INS integration system for seamless pedestrian navigation has been developed. The walking state detection, including step detection and turn detection were studied to aid INS-based dead reckoning navigation. In order to improve WIFI positioning accuracy, map-based information has been introduced into the fingerprinting database.
In summary, the contributions of this research were to provide solutions, as well as reliability and separability measures, for the design of integrated multi-sensor navigation systems for different applications, with the goal of more robust, accurate and reliable navigation solutions.