Accuracy Enhancement of Inertial Sensors Utilizing High Resolution Spectral Analysis

Aboelmagd Noureldin,Tashfeen Karamat,Don Mcgaughey,Aini Hussain,Michael Korenberg,Ahmed El-Shafie,Justin Armstrong

doi:10.3390/s120911638

Aboelmagd Noureldin, Tashfeen Karamat + Show 5 more

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https://doi.org/10.3390/s120911638

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Abstract

In both military and civilian applications, the inertial navigation system (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. The accuracy enhancement of INS sensors and the integration of INS with GPS are the subjects of widespread research. Wavelet de-noising of INS sensors has had limited success in removing the long-term (low-frequency) inertial sensor errors. The primary objective of this research is to develop a novel inertial sensor accuracy enhancement technique that can remove both short-term and long-term error components from inertial sensor measurements prior to INS mechanization and INS/GPS integration. A high resolution spectral analysis technique called the fast orthogonal search (FOS) algorithm is used to accurately model the low frequency range of the spectrum, which includes the vehicle motion dynamics and inertial sensor errors. FOS models the spectral components with the most energy first and uses an adaptive threshold to stop adding frequency terms when fitting a term does not reduce the mean squared error more than fitting white noise. The proposed method was developed, tested and validated through road test experiments involving both low-end tactical grade and low cost MEMS-based inertial systems. The results demonstrate that in most cases the position accuracy during GPS outages using FOS de-noised data is superior to the position accuracy using wavelet de-noising.

Highlights

In numerous applications, inertial navigation system (INS) and global positioning system (GPS) are two complementary technologies that can be integrated to provide reliable positioning and navigation information for land vehicles
It should be noted that this process of de-noising is appropriate for stationary data, and that inertial sensor data is typically non-stationary since they are measurements of the vehicle motion dynamics and the sensor noise is known to be non-stationary
The experimental work discussed for tactical grade IMUs validates fast orthogonal search (FOS) as an inertial sensor accuracy enhancement technique that is applicable to a real INS integrated with a GPS and applicable to relatively long trajectories

Summary

Introduction

Inertial navigation system (INS) and global positioning system (GPS) are two complementary technologies that can be integrated to provide reliable positioning and navigation information for land vehicles. In the event of loss, denial of use, or degradation of the GPS signal (i.e., due to signal jamming in military electronic warfare operations, or due to signal blockage while driving through urban canyons), INS can be an invaluable source of redundancy [1]. 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 [2]. The inertial sensors employed in an INS have significantly complex short-term (high-frequency) and long-term (low frequency) noise characteristics that are produced by many different error sources

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