Performance evaluation of low cost MEMS-based IMU integrated with GPS for land vehicle navigation application

Land vehicle navigation system (LVNS) technology is a subject of great interest today due to its potential for both consumer and business vehicle markets. Global Positioning System (GPS) is a common choice for positioning in such systems. However, GPS alone is incapable of providing continuous and reliable positioning, because of its inherent dependency on external electromagnetic signals. The availability of low cost MEMS inertial sensors is now making it feasible to use Inertial Navigation System (INS) in conjunction with GPS to fulfill the demands of such systems. This thesis therefore evaluates the positioning capability of GPS/INS integrated systems utilizing MEMS Inertial Measurement Units (IMU) for LVNS and investigates on methods to improve its performance.; The primary piece of equipment used is a MEMS-based Crista IMU (from Cloud Cap Technology Inc.) and a NovAtel OEM4 GPS receiver.; The performance of the system is assessed primarily in terms of position and velocity errors computed with respect to an independent navigation solution. The results show that under complete GPS coverage, the GPS/MEMS INS integrated system provides accuracies of better than 0.4 m in the position domain. The integrated system provides RMS horizontal position accuracies better than 7 m in a severely signal degraded environment. The performance improves significantly with the proposed use of vehicle motion constraints and backward smoothing techniques. Overall the results confirm the strong potential of GPS/MEMS INS integrated systems for their use in land vehicle navigation applications. (Abstract shortened by UMI.)...