Browsing by Author "JIANG, YF"

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ERROR ESTIMATION OF INS GROUND ALIGNMENT THROUGH OBSERVABILITY ANALYSIS
(1992-01-01)
JIANG, YF
;
LIN, YP
;
電控工程研究所
;
Institute of Electrical and Control Engineering
A systematic analysis of the observability of an inertial navigation system (INS) in ground alignment with Bar-Itzhack and Berman's error model is presented. It is shown that the unobservable states are separately contained in two decoupled subspaces. The constraints on the selection of unobservable states are discussed. An estimation algorithm which is derived fully from the horizontal velocity outputs for computing the misalignment angles is provided. It reveals that the azimuth error can be entirely estimated from the estimates of leveling error and leveling error rate, without using gyro output signals explicitly.
IMPROVED STRAPDOWN CONING ALGORITHMS
(1992-04-01)
JIANG, YF
;
LIN, YP
;
電控工程研究所
;
Institute of Electrical and Control Engineering
Three improved algorithms for strapdown attitude computation utilizing accumulated gyro increments from the previous and current update are developed and evaluated analytically under classical coning motion. The error criterion of Miller [6] is now derived directly from the rotation vector concept. The accuracy of updating rotation vector estimation can be improved at least two orders of magnitude as compared with those of conventional algorithms. The proposed algorithm is equivalent to increasing the number of gyro samples used in the conventional method and it requires less computer loading also.