Gravity Requirements for Compensation of Ultra-Precise Inertial Navigation

2005 ◽  
Vol 58 (3) ◽  
pp. 479-492 ◽  
Author(s):  
Jay Hyoun Kwon ◽  
Christopher Jekeli
Keyword(s):  
Inertial Sensors ◽  
Interpolation Method ◽  
Gravity Data ◽  
Inertial Navigation ◽  
Navigation Systems ◽  
Gravity Compensation ◽  
Global Gravity ◽  
Navigation Error ◽  
Global Gravity Model

Precision inertial navigation depends not only on the quality of the inertial sensors (accelerometers and gyros), but also on the accuracy of the gravity compensation. With a view toward the next-generation inertial navigation systems, based on sensors whose errors contribute as little as a few metres per hour to the navigation error budget, we have analyzed the required quality of gravity compensation to the navigation solution. The investigation considered a standard compensation method using ground data to predict the gravity vector at altitude for aircraft free-inertial navigation. The navigation effects of the compensation errors were examined using gravity data in two gravimetrically distinct areas and a navigation simulator with parameters such as data noise and resolution, supplemental global gravity model noise, and on-track interpolation method. For a typical flight trajectory at 5 km altitude and 300 km/hr aircraft speed, the error in gravity compensation contributes less than 5 m to the position error after one hour of free-inertial navigation if the ground data are gridded with 2 arcmin resolution and are accurate to better than 5 mGal.

scholarly journals Analysis and Verification of Rotation Modulation Effects on Inertial Navigation System based on MEMS Sensors

2013 ◽  
Vol 66 (5) ◽  
pp. 751-772 ◽  
Author(s):  
Xueyun Wang ◽  
Jie Wu ◽  
Tao Xu ◽  
Wei Wang
Keyword(s):  
Navigation System ◽  
Inertial Navigation System ◽  
Inertial Sensors ◽  
Inertial Navigation ◽  
Cost Effective ◽  
Navigation Systems ◽  
Inertial Navigation Systems ◽  
Mems Sensors ◽  
Micro Electro Mechanical Systems ◽  
Position Accuracy

Inertial Navigation Systems (INS) were large, heavy and expensive until the development of cost-effective inertial sensors constructed with Micro-electro-mechanical systems (MEMS). However, the large errors and poor error repeatability of MEMS sensors make them inadequate for application in many situations even with frequent calibration. To solve this problem, a systematic error auto-compensation method, Rotation Modulation (RM) is introduced and detailed. RM does no damage to autonomy, which is one of the most important characteristics of an INS. In this paper, the RM effects on navigation performance are analysed and different forms of rotation schemes are discussed. A MEMS-based INS with the RM technique applied is developed and specific calibrations related to rotation are investigated. Experiments on the developed system are conducted and results verify that RM can significantly improve navigation performance of MEMS-based INS. The attitude accuracy is improved by a factor of 5, and velocity/position accuracy by a factor of 10.

scholarly journals Generalized geoidal estimators for deterministic modifications of spherical Stokes' function

2010 ◽  
Vol 40 (1) ◽  
pp. 45-64 ◽  
Author(s):  
Michal Šprlák
Keyword(s):  
Gravity Model ◽  
Spherical Harmonic ◽  
Gravity Data ◽  
Surface Integral ◽  
Terrestrial Gravity ◽  
Global Gravity ◽  
Higher Derivatives ◽  
Stokes Integral ◽  
Global Gravity Model ◽  
Local Geoid

Generalized geoidal estimators for deterministic modifications of spherical Stokes' function Stokes' integral, representing a surface integral from the product of terrestrial gravity data and spherical Stokes' function, is the theoretical basis for the modelling of the local geoid. For the practical determination of the local geoid, due to restricted knowledge and availability of terrestrial gravity data, this has to be combined with the global gravity model. In addition, the maximum degree and order of spherical harmonic coefficients in the global gravity model is finite. Therefore, modifications of spherical Stokes' function are used to obtain faster convergence of the spherical harmonic expansion. Decomposition of Stokes' integral and modifications of Stokes' function have been studied by many geodesists. In this paper, the proposed deterministic modifications of spherical Stokes' function are generalized. Moreover, generalized geoidal estimators, when the Stokes' integral is decomposed in to spectral and frequency domains, are introduced. Higher derivatives of spherical Stokes' function and their numerical stability are discussed. Filtering and convergence properties for deterministic modifications of the spherical Stokes' function in the form of a remainder of the Taylor polynomial are studied as well.

scholarly journals A Reconstruction Filter for Saturated Accelerometer Signals Due to Insufficient FSR in Foot-mounted Inertial Navigation System

2021 ◽  
Author(s):  
Chi-Shih Jao ◽  
Andrei M. Shkel
Keyword(s):  
Inertial Sensors ◽  
Inertial Navigation ◽  
Gaussian Process Regression ◽  
Navigation Systems ◽  
Analog Device ◽  
Bias Drift ◽  
Pedestrian Navigation ◽  
Angular Velocities ◽  
Reconstruction Filter ◽  
Commercial Off The Shelf

In pedestrian inertial navigation, one possible placement of Inertial Measurement Units (IMUs) is on a footwear. This placement allows to limit the accumulation of navigation errors due to the bias drift of inertial sensors and is generally a preferable placement of sensors to achieve the highest precision of pedestrian inertial navigation. However, inertial sensors mounted on footwear experience significantly higher accelerations and angular velocities during regular pedestrian activities than during more conventional navigation tasks, which could exceed Full Scale Range (FSR) of many commercial-off-the-shelf IMUs, therefore degrading accuracy of pedestrian navigation systems. This paper proposes a reconstruction filter to mitigate localization error in pedestrian navigation due to insufficient FSR of inertial sensors. The proposed reconstruction filter approximates immeasurable accelerometer's signals with a triangular function and estimates the size of the triangles using a Gaussian Process regression. To evaluate performance of the proposed reconstruction filter, we conducted two series of indoor pedestrian navigation experiments with a VectorNav VN-200 IMU and an Analog Device ADIS16497-3 IMU. In the first series of experiments, forces experienced by the IMUs did not exceed the FSRs of the sensors, while in the second series, the forces surpassed the FSR of the VN-200 IMU and saturated the accelerometer's readings. The saturated readings reduced the accuracy of estimated positions using the VN-200 by 1.34× and 3.37× along horizontal and vertical directions. When applying our proposed reconstruction filter to the saturated measurements, the navigation accuracy was increased by 5% horizontally and 50% vertically, as compared to using unreconstructed signals.

Pedestrian navigation using inertial sensors and altitude error correction

Sensor Review ◽  
2015 ◽  
Vol 35 (1) ◽  
pp. 68-75 ◽  
Author(s):  
Wen Liu ◽  
Yingjun Zhang ◽  
Xuefeng Yang ◽  
Shengwei Xing
Keyword(s):  
Error Correction ◽  
Inertial Sensors ◽  
Angular Rate ◽  
Gait Recognition ◽  
Inertial Navigation ◽  
Navigation Systems ◽  
Content Type ◽  
Positioning Errors ◽  
Walking Motion ◽  
Dynamic Time

Purpose – The aim of this article is to present a PIN (pedestrian inertial navigation) solution that incorporates altitude error correction, which eliminates the altitude error accurately without using external sensors. The main problem of PIN is the accumulation of positioning errors due to the drift caused by the noise in the sensors. Experiment results show that the altitude errors are significant when navigating in multilayer buildings, which always lead to localization to incorrect floors. Design/methodology/approach – The PIN proposed is implemented over an inertial navigation systems (INS) framework and a foot-mounted IMU. The altitude error correction idea is identifying the most probable floor of each horizontal walking motion. To recognize gait types, the walking motion is described with angular rate measured by IMU, and the dynamic time warping algorithm is used to cope with the different dimension samples due to the randomness of walking motion. After gait recognition, the altitude estimated with INS of each horizontal walking is checked for association with one of the existing in a database. Findings – Experiment results show that high accuracy altitude is achieved with altitude errors below 5 centimeters for upstairs and downstairs routes in a five floors building. Research limitations/implications – The main limitations of the study is the assumption that accuracy floor altitude information is available. Originality/value – Our PIN system eliminates altitude errors accurately and intelligently, which benefits from the new idea of combination of gait recognition and map-matching. In addition, only one IMU is used which is different from other approach that use external sensors.

scholarly journals Gravity Compensation Using EGM2008 for High-Precision Long-Term Inertial Navigation Systems

Sensors ◽  
2016 ◽  
Vol 16 (12) ◽  
pp. 2177 ◽  
Author(s):  
Ruonan Wu ◽  
Qiuping Wu ◽  
Fengtian Han ◽  
Tianyi Liu ◽  
Peida Hu ◽  
...  
Keyword(s):  
High Precision ◽  
Inertial Navigation ◽  
Navigation Systems ◽  
Gravity Compensation ◽  
Inertial Navigation Systems

scholarly journals IMPROVEMENT OF NAVIGATION SYSTEMS OF VEHICLES BY MEANS OF INERTIAL SENSORS AND INFORMATION PROCESSING USING PROBABILITY-GEOMETRIC METHODS

2020 ◽  
Vol 1 (46) ◽  
pp. 353-364
Author(s):  
Topolskov E ◽  
◽  
Beljaevskiy L L ◽  
Serdjuke A ◽  
◽  
...  
Keyword(s):  
Information Processing ◽  
Moving Objects ◽  
Inertial Sensors ◽  
Inertial Navigation ◽  
Satellite Navigation ◽  
Navigation Systems ◽  
Inertial Navigation Systems ◽  
Ground Vehicle ◽  
Geometric Methods ◽  
Urgent Task

Providing high accuracy of the coordinates and trajectories of objects by measurements conducted in navigation systems and complexes is an urgent task, which improves safety and efficiency of different modes of transport. However difficult environmental conditions, where vehicles are commonly used, stipulate influence of different factors on performance of onboard satellite navigation receivers, which are used as basic navigation devices for ground vehicle nowadays. Setting on cars used for common purposes additional navigation devices, which provide better performance, in most cases is economically unreasonable. Economically reasonable ways to improve onboard navigation complexes of vehicles, which are used for common purposes, are examined in this article. Functional diagram and principles of work of navigational complex, which uses the satellite navigation receiver and simplified variant of inertial navigation system is pointed as well. Also, the justification of methods for minimizing the error formats of coordinates and trajectories of moving objects based on information processing in multipositional, in particular satellite-inertial navigation systems and complexes, is presented. The obtained research results give an opportunity to develop an algorithm for coordinate refinement, which can be implemented in the improved on-board navigational complex of vehicle. KEY WORDS: NAVIGATION SYSTEMS AND COMPLEXES, INERTIAL SENSORS, NAVIGATION DEFINITIONS, ACCURACY AND RELIABILITY OF COORDINATES AND TRAJECTORIES OF MOVING OBJECTS, ELLIPS OF ERRORS, PROBABILISTIC-GEOMETRIC METHODS.

scholarly journals Vehicle Navigation Systems Involving Inertial Sensors and Odometry Data from On-Board Diagnostics in Non-Gps Applications

2020 ◽  
Vol 3 (22) ◽  
pp. 259-266 ◽  
Author(s):  
Piotr Prusaczyk ◽  
Jarosław Panasiuk ◽  
Leszek Baranowski
Keyword(s):  
Inertial Sensors ◽  
Inertial Navigation ◽  
Initial Position ◽  
Vehicle Navigation ◽  
Gps Data ◽  
Navigation Systems ◽  
Process Orientation ◽  
Positioning Errors ◽  
Position And Orientation ◽  
Navigation Errors

This paper explores the applicability of on-board diagnostics data for minimizing inertial navigation errors in vehicles. The results of driving tests were presented and discussed. Knowledge  of a vehicle’s exact initial position and orientation was crucial in the navigation process. Orientation errors at the beginning of navigation contributed to positioning errors. GPS data were not processed by the algorithm during navigation.

scholarly journals Dual MIMU Pedestrian Navigation by Inequality Constraint Kalman Filtering

2016 ◽  
Author(s):  
Wei Shi ◽  
Yang Wang ◽  
Yuanxin Wu
Keyword(s):  
Inertial Sensors ◽  
Low Cost ◽  
Inertial Navigation ◽  
Inequality Constraint ◽  
Time Range ◽  
Navigation Systems ◽  
Inertial Navigation Systems ◽  
Pedestrian Navigation ◽  
External Assistance ◽  
Constraint Method

The foot-mounted inertial navigation system is an important application of pedestrian navigation as it in principle does not rely any external assistance. A real-time range decomposition constraint method is proposed in this paper to combine the information of dual foot-mounted inertial navigation systems. It is well known that low-cost inertial sensors with ZUPT (zero-velocity update) and range decomposition constraint perform better than in either single way. This paper recommends that the distance of separation between the position estimates of feet-mounted inertial navigation systems be restricted in the ellipsoidal constraint which relates to the maximum step and leg height. The performance of the proposed method is studied utilizing experimental data. The results indicate that the method can effectively correct the dual navigation systems’ position over the existing spherical constraint.

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