title: A stationary north-finding scheme for an azimuth rotational IMU utilizing a linear state equality constraint.
abstract: The Kalman filter (KF) has always been used to improve north-finding performance under practical conditions. By analyzing the characteristics of the azimuth rotational inertial measurement unit (ARIMU) on a stationary base, a linear state equality constraint for the conventional KF used in the fine north-finding filtering phase is derived. Then, a constrained KF using the state equality constraint is proposed and studied in depth. Estimation behaviors of the concerned navigation errors when implementing the conventional KF scheme and the constrained KF scheme during stationary north-finding are investigated analytically by the stochastic observability approach, which can provide explicit formulations of the navigation errors with influencing variables. Finally, multiple practical experimental tests at a fixed position are done on a postulate system to compare the stationary north-finding performance of the two filtering schemes. In conclusion, this study has successfully extended the utilization of the stochastic observability approach for analytic descriptions of estimation behaviors of the concerned navigation errors, and the constrained KF scheme has demonstrated its superiority over the conventional KF scheme for ARIMU stationary north-finding both theoretically and practically.
authors: Department of Navigation and Communication, Navy Submarine Academy, Qingdao 266042, China. hpyu_qtxy@163.com.
authors: Huapeng
authors: H
authors: Yu
authors: Department of Navigation and Communication, Navy Submarine Academy, Qingdao 266042, China. seapeter@163.com.
authors: Hai
authors: H
authors: Zhu
authors: Department of Navigation and Communication, Navy Submarine Academy, Qingdao 266042, China. dygao@263.net.
authors: Dayuan
authors: D
authors: Gao
authors: College of Aerospace Science and Engineering, National University of Defense Technology, Changsha 410073, China. yumeng4517@gmail.com.
authors: Meng
authors: M
authors: Yu
authors: College of Mechatronics Engineering and Automation, National University of Defense Technology, Changsha 410073, China. wenqiwu_lit@nudt.edu.cn.
authors: Wenqi
authors: W
authors: Wu