Instantaneous Observability of Tightly Coupled SINS/GPS during Maneuvers

• Published in: Sensors (Basel, Switzerland) Vol. 16; no. 6; p. 765
• Main Authors: Jiang, Junxiang, Yu, Fei, Lan, Haiyu, Dong, Qianhui
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 27.05.2016; MDPI
• Subjects: angle maneuver; Global Positioning System; GPS; instantaneous observability matrix (IOM); Joining; Kalman filters; Maneuvers; Mathematical analysis; Navigation systems; reconstructed psi-angle model; Satellite navigation systems; Sensors; Simulation; SINS; Strapdown inertial navigation; three-channel system; translational maneuver; two-channel system; China; three-channel system; instantaneous observability matrix (IOM); reconstructed psi-angle model; translational maneuver; GPS; two-channel system; angle maneuver; SINS
• ISSN: 1424-8220; 1424-8220
• DOI: 10.3390/s16060765

The tightly coupled strapdown inertial navigation system (SINS)/global position system (GPS) has been widely used. The system observability determines whether the system state can be estimated by a filter efficiently or not. In this paper, the observability analysis of a two-channel and a three-channel tightly coupled SINS/GPS are performed, respectively, during arbitrary translational maneuvers and angle maneuvers, where the translational maneuver and angle maneuver are modeled. A novel instantaneous observability matrix (IOM) based on a reconstructed psi-angle model is proposed to make the theoretical analysis simpler, which starts from the observability definition directly. Based on the IOM, a series of theoretical analysis are performed. Analysis results show that almost all kinds of translational maneuver and angle maneuver can make a three-channel system instantaneously observable, but there is no one translational maneuver or angle maneuver can make a two-channel system instantaneously observable. The system's performance is investigated when the system is not instantaneously observable. A series of simulation studies based on EKF are performed to confirm the analytic conclusions.