Application of fast orthogonal search to accuracy enhancement of inertial sensors for land vehicle navigation

In both military and civilian applications, Inertial Navigation Systems (INS) and the Global Positioning System (GPS) are two complementary technologies that can be integrated to provide reliable positioning and navigation information for land vehicles. INS is inherently immune to the signal jamming, spoofing, and blockage vulnerabilities of GPS, but the accuracy of INS is significantly affected by the error characteristics of the inertial sensors it employs. Thus, the accuracy enhancement of inertial sensors and the integration of INS with GPS are subjects of pervasive research. Current accuracy enhancement techniques include optimal low-pass filtering and wavelet denoising techniques, but they have had limited success in removing the long-term (low-frequency) inertial sensor error components.; The primary objective of this thesis is to develop a novel inertial sensor accuracy enhancement technique that can remove the error components from inertial sensor measurements prior to computation of INS navigation data and integration with GPS data. The proposed Fast Orthogonal Search (FOS) based INertial Sensor Accuracy ENhancer (FOS-INSAEN) employs FOS to estimate components of the true vehicle motion dynamics and consequently reject inertial sensor error components.; FOS-INSAEN was developed, tested and validated through simulation work as well as experimental work involving the execution of a land vehicle trajectory and the acquisition of tactical-grade inertial sensor and GPS measurements. The results show that FOS-INSAEN is capable of inertial sensor accuracy enhancement that is comparable or superior to wavelet denoising. Furthermore, the results indicate that pre-processing inertial sensor outputs with FOS-INSAEN can contribute to accuracy enhancement in the position domain during GPS outages.