Mechanization of a Robust Navigation Scheme for Land Applications Employing GNSS/INS Augmented with Zero Velocity Update

GNSS/INS Integrated Navigation systems mechanized for Land based applications face certain challenges especially near skyscraper, mountainous regions and high foliage environments wherein GNSS signals get interrupted.While Inertial Navigation System (INS) and Global Navigation Satellite System (GNSS) are widely used in augmentation but the integrated navigation solution can get compromised in GNSS-denied environments.This research work explores the integration of GNSS with low-cost Micro-Electromechanical System (MEMS) Inertial Measurement Unit (IMU) and Zero Update Position and Timing (ZUPT) rendering a robust navigation solution for land applications.ZUPT is used to mitigate accelerometers and gyroscope biases and resultantly it alleviates the errors in position, velocity and attitude especially in a GNSS-denied scenario.ZUPT is enabled when the host vehicle stops and velocity of the host vehicle becomes zero.ZUPT corrections employing Kalman Filter algorithms significantly contains the accumulated errors in position, velocity and attitude.The study investigates the impact of different types of errors (random, fixed and growing errors) in GNSS including complete unviability on the INS/GNSS integrated solution.It has been observed that, when time growing errors are introduced in GNSS output, it has the worst effect on its overall accuracy.To counteract potential degradation in position computation ensuing from GNSS denial or interruption, this work corroborates the efficacy of ZUPT.ZUPT updates strengthen the system's robustness and accuracy of INS/GNSS Integrated solution.The proposed scheme can be employed for any land application including autonomous commercial land vehicles, navigation in tunnels, mining work and pedestrian navigation system etc.