A Dual-Axis Rotation Scheme for Redundant Rotational Inertial Navigation System

Abstract

A redundant rotational inertial navigation system (RRINS) comprises a redundant inertial measurement unit (RIMU) and a turntable for improving reliability and navigation accuracy. Because of the multi-sensor configuration, the RIMU has a more complex error model compared with the traditional orthogonal inertial measurement unit (IMU). Therefore, the RIMU-based rotation scheme cannot simply replicate the traditional IMU-based rotation scheme. In this study, a dual-axis rotation scheme for RIMU characteristics is proposed. First, the error model of the RIMU was established, and the error compensation of RIMU caused by rotation was analyzed. Second, the principles of rotation axis switching and reciprocating rotation were summarized, and a dual-axis rotation scheme was designed by these principles. Finally, the rotation scheme was applied to an RRINS prototype consisting of RIMU (four fiber optic gyroscopes + four quartz accelerometers) and a dual-axis turntable, and then simulations and experiments were performed. The results of the simulations and experiments show that the positioning accuracy of RRINS can be obviously improved by using the proposed rotation scheme.

An Improved Rotational Modulation Scheme for Tri-Axis Rotational Inertial Navigation System (RINS) with Fiber Optic Gyro (FOG)

“…In the absence of external information input during navigation, the inertial navigation system (INS) can output the complete navigation parameters [1][2][3][4][5]. RINS has a similar frame and rotation axis as the platform inertial navigation system, which can offset the constant and slowly-varying errors of the inertial measurement unit (IMU) and improve the navigation accuracy by about one order of magnitude [6][7][8][9]. RINS also has advantages in initial alignment [10,11] and self-calibration [12][13][14][15][16][17], which have drawn much attention recently [18][19][20][21].…”

Novel rotation scheme for dual-axis rotational inertial navigation system based on body diagonal rotation of inertial measurement unit

“…The constant drift and slow-varying errors of inertial sensors are the main factors affecting the accuracy of INSs. The rotational INS (RINS) uses the regular rotation of the IMU to compensate for these errors through different rotation sequences, so the design of the rotation scheme is the key to determining the improvement in system accuracy [16][17][18][19][20][21][22][23]. Common single-and dual-axial RINSs take one sensitive axis or two directional inertial sensors of the IMU as the rotation axis to produce different rotation schemes by changing the rotation speed, direction, and sequence of the rotation axis.…”

“…This can be regarded as two single-axis alternate rotations, so the error in any axis can be compensated to a certain extent. Zhou et al [22] designed an eight-position rotation scheme based on the error compensation principle of the IMU, which optimizes the relationship between the installation error and rotation strategy. Xu et al [23] combined the motion constraint of the carrier with the rotation modulation to give a 32-position rotation scheme that enhances navigation accuracy.…”