Analysis and Verification of Rotation Modulation Effects on Inertial Navigation System based on MEMS Sensors

Abstract

Inertial Navigation Systems (INS) were large, heavy and expensive until the development of cost-effective inertial sensors constructed with Micro-electro-mechanical systems (MEMS). However, the large errors and poor error repeatability of MEMS sensors make them inadequate for application in many situations even with frequent calibration. To solve this problem, a systematic error auto-compensation method, Rotation Modulation (RM) is introduced and detailed. RM does no damage to autonomy, which is one of the most important characteristics of an INS. In this paper, the RM effects on navigation performance are analysed and different forms of rotation schemes are discussed. A MEMS-based INS with the RM technique applied is developed and specific calibrations related to rotation are investigated. Experiments on the developed system are conducted and results verify that RM can significantly improve navigation performance of MEMS-based INS. The attitude accuracy is improved by a factor of 5, and velocity/position accuracy by a factor of 10. K E Y WO R D S

Self-Alignment MEMS IMU Method Based on the Rotation Modulation Technique on a Swing Base

“…The RMT effect is related to the angular rate of rotation. Theoretically, the faster the rate of rotation, the more obvious the effect of error suppression [ 47 , 48 ]. However, for practical engineering applications, a too fast angular rate of rotation cause control difficulties, high frequency noise, and additional error caused by the motor.…”

A Novel MEMS Gyro North Finder Design Based on the Rotation Modulation Technique

“…It has also been studied in the low-cost MEMS IMUs in recent years [14,25]. From the frequency domain, there is a more intuitive understanding of the rotation modulation.…”

“…Rotation modulation is often used to improve the inertial navigation system precision [14,15,16]. It refers to rotating the IMUs around one axis, or multiple axes continuously or discretely.…”

“…It refers to rotating the IMUs around one axis, or multiple axes continuously or discretely. The inertial sensors’ bias drift and other slowly changing errors can be modulated to zero-mean periodical values [14,16]. This makes the MEMS gyro north finder an intriguing possibility and a development trend [15].…”

High precision locking control based on fiber optic gyro and photoelectric encoder for rotational inertial navigation system

“…The information of angle measuring components installed on the rotation gimbals is read by computer and combined with computer's rotation instructions to calculate corresponding control errors which are used to control motion of motors [11]. The precision of this locking control mode is restricted immensely by the performance of the angle measuring components accordingly.…”