Journal ArticleDOI
Coarse Alignment of a Ship's Strapdown Inertial Attitude Reference System Using Velocity Loci
TLDR
A novel estimation method for fast initial coarse alignment of a ship's strapdown inertial attitude reference system using only inertial measurement unit (IMU) measurements for quasi-static alignment and IMU measurements with GPS aiding for moving-base alignment is presented.Abstract:
This paper presents a novel estimation method for fast initial coarse alignment of a ship's strapdown inertial attitude reference system using only inertial measurement unit (IMU) measurements for quasi-static alignment and IMU measurements with GPS aiding for moving-base alignment. Unlike several current techniques, the presented estimation method is effective with any initial attitude error. The estimator is based on the decomposition of the attitude quaternion into separate Earth motion, inertial rate, and alignment quaternions. The alignment quaternion is estimated using a minimum variance fit between loci of body- and navigation-frame velocity vectors using solutions to Wahba's problem. One set of vectors is derived from time integrals of measured vehicle motions, and the second set is derived from Earth motion and GPS data (when moving). For the case of quasi-static alignment, an algebraic expression for the covariance of the attitude estimate as a function of the variance of navigation-frame velocity disturbances is developed. It is shown that, by averaging and interleaving the velocity vectors, the resulting attitude estimate is improved over sequential sampling techniques. It is further shown, for a maneuvering vessel, that a continuous estimate of the attitude error covariance can be generated from the IMU data. This latter feature allows direct initialization of a follow-on fine-alignment stochastic estimator's covariance matrix. Results are presented for quasi-static alignment using inertial sensors only and for full in-motion alignment using navigation-frame GPS velocity and position aiding.read more
Citations
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Journal ArticleDOI
Velocity/Position Integration Formula Part I: Application to In-Flight Coarse Alignment
Yuanxin Wu,Xianfei Pan +1 more
TL;DR: An optimization-based coarse alignment approach that uses GPS position/velocity as input, founded on the newly-derived velocity/position integration formulae is proposed, and can serve as a nice coarse in-flight alignment without any prior attitude information for the subsequent fine Kalman alignment.
Journal ArticleDOI
Initial Alignment by Attitude Estimation for Strapdown Inertial Navigation Systems
TL;DR: A novel initial alignment method for the strapdown inertial navigation system (SINS), which transforms the attitude alignment into an attitude estimation problem, and the application of the proposed generalized velocity integration formula to attenuate the accumulated errors in vector observations caused by the traditional velocity Integration formula.
Journal ArticleDOI
A Fast SINS Initial Alignment Scheme for Underwater Vehicle Applications
TL;DR: A new SINS initial alignment scheme aided by the velocity derived from Doppler Velocity Log (DVL) is proposed to solve the problem of high Strapdown Inertial Navigation System alignment accuracy within a short period of time.
Journal ArticleDOI
Initial Alignment for a Doppler Velocity Log-Aided Strapdown Inertial Navigation System With Limited Information
Lubin Chang,Yang Li,Boyang Xue +2 more
TL;DR: An ingenious alignment scheme for a Doppler velocity log-aided strapdown inertial navigation system with only the initial velocity and position information is proposed, which can not only align the attitude to high precision within very short time, but also determine the velocity andposition with satisfied accuracy.
Journal ArticleDOI
Kalman-Filtering-Based In-Motion Coarse Alignment for Odometer-Aided SINS
TL;DR: Experimental results illustrate that the proposed closed- loop approach can estimate the attitude matrix from the current body frame to the initial body frame better than the existing open-loop approach, which results in improved alignment accuracy as compared with the existing optimization-based alignment method for the odometer-aided SINS when the vehicle maneuvers severely.
References
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Book
Approximation Theorems of Mathematical Statistics
TL;DR: In this paper, the basic sample statistics are used for Parametric Inference, and the Asymptotic Theory in Parametric Induction (ATIP) is used to estimate the relative efficiency of given statistics.
Book
Strapdown inertial navigation technology
David Titterton,John Weston +1 more
TL;DR: In this paper, the physical principles of inertial navigation, the associated growth of errors and their compensation, and their application in a broad range of applications are discussed, drawing current technological developments and providing an indication of potential future trends.
Journal ArticleDOI
Three-axis attitude determination from vector observations
Malcolm D. Shuster,S. D. Oh +1 more
TL;DR: Two computationally efficient algorithms are presented for determining three-axis attitude from two or more vector observations that are useful to the mission analyst or spacecraft engineer for the evaluation of launch-window constraints or of attitude accuracies for different attitude sensor configurations.
Related Papers (5)
Optimization-based alignment for inertial navigation systems: Theory and algorithm
Velocity/Position Integration Formula Part I: Application to In-Flight Coarse Alignment
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