An Improved Rotation Scheme for Dual-Axis Rotational Inertial Navigation System

In previous research, a semi-strapdown inertial navigation system (SSINS), based on micro-electro-mechanical system (MEMS) sensors, was able to realize over-range measurement of the attitude information of high-rotation missiles by constructing a single axis “spin reduction” platform. However, the MEMS sensors in SSINS were corrupted by significant sensor errors. In order to further improve SSINS measurement accuracy, a rotational modulation technique has been introduced to compensate for sensor errors. The ideal modulation angular velocity is changed sharply to achieve a constant speed, while in practical applications, the angular rate of the rotating mechanism’s output needs to go through an acceleration-deceleration process. Furthermore, the stability of the modulation angular rate is difficult to achieve in a high-speed rotation environment. In this paper, a novel rotation scheme is proposed which can effectively suppress the residual error in the navigation coordinate system caused by the modulation angular rate error, including the acceleration-deceleration process and instability of angular rate. The experiment results show that the position and attitude accuracy of the new rotation scheme was increased by more than 56%. In addition, the proposed scheme is applicable to navigation accuracy improvement under various dynamic conditions.

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A rotation scheme for dual-unit inertial navigation system based on MEMS sensors

2018 IEEE CSAA Guidance, Navigation and Control Conference (CGNCC) ◽

10.1109/gncc42960.2018.9019108 ◽

2018 ◽

Author(s):

Lixiang Zhang ◽

Lei Wang ◽

Zengiun Liu ◽

Jingxuan Ban

Keyword(s):

Navigation System ◽

Inertial Navigation System ◽

Inertial Navigation ◽

Mems Sensors ◽

Rotation Scheme

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A System-Level Self-Calibration Method for Installation Errors in A Dual-Axis Rotational Inertial Navigation System

Sensors ◽

10.3390/s19184005 ◽

2019 ◽

Vol 19 (18) ◽

pp. 4005 ◽

Cited By ~ 3

Author(s):

Bai ◽

Lai ◽

Lyu ◽

Xu ◽

Liu ◽

...

Keyword(s):

Navigation System ◽

Inertial Navigation System ◽

Angular Rate ◽

Inertial Navigation ◽

Calibration Method ◽

System Level ◽

Measurement Unit ◽

Self Calibration ◽

Rotation Axes ◽

Rotation Scheme

In a dual-axis rotational inertial navigation system (RINS), there are two kinds of installation errors, nonorthogonal installation errors of inertial sensors, and installation errors between the inertial measurement unit (IMU) and rotation axes. Traditionally, these two errors are not considered simultaneously. Thus, they are calibrated separately by different estimation algorithms and rotation schemes. In this paper, a system-level self-calibration method for installation errors of a dual-axis RINS is proposed. Based on the Kalman filter, the measurement model is reestablished to ensure that all installation errors can be estimated together. First, the relationship between the initial attitude and subsequent attitude of IMU during rotation is used as a constraint to estimate nonorthogonal installation errors of accelerometers, and installation errors between the IMU and rotation axes. Then, the angular rate of the rotation mechanism is used as a reference to estimate nonorthogonal installation errors of the gyros. The rotation scheme of the IMU is designed to make all installation errors observable, and the observability of the system is analyzed based on the piecewise constant system method. Simulation and laboratory experiment results suggest that installation errors can be effectively estimated by the proposed method, thereby avoiding the complex separating process.

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