Navigation Grade MEMS IMU for A Satellite.

Wanliang Zhao,Yuxiang Cheng,Yijie Rong,Sihan Zhao,Jiawei Chen,Jie Duan,Xiaomao Hu

doi:10.3390/mi12020151

Abstract

This paper presents a navigation grade micro-electromechanical system (MEMS) inertial measurement unit (IMU) that was successfully applied for the first time in the Lobster-Eye X-ray Satellite in July 2020. A six-axis MEMS gyroscope redundant configuration is adopted in the unit to improve the performance through mutual calibration of a set of two-axis gyroscopes in the same direction. In the paper, a satisfactory precision of the gyroscope is achieved by customized and self-calibration gyroscopes whose parameters are adjusted at the expense of bandwidth and dynamics. According to the in-orbit measured data, the MEMS IMU provides an outstanding precision of better than 0.02 °/h (1σ) with excellent bias instability of 0.006 °/h and angle random walk (ARW) of around 0.003 °/h1/2. It is the highest precision MEMS IMU for commercial aerospace use ever publicly reported in the world to date.

Highlights

The gyroscope; (2) the orthogonality of the driving direction X and the sensitive direction Y, (3) For system-level calibration, the gyroscope noise can be lowered by the mutual whose non-orthogonal term will lead to the drift of the gyroscope signal; (3) the asymmetry calibration of two-axis MEMS gyroscopes with parallel redundant configuration in the Micromachines 2021, 12, 151 effect on the gyroscope arising from frequency split and damping split; (4) the change of resonator structure parameters caused by the environmental stress
In anIn effort to overcome this challenge, two movable mass blocks blocks of the gyroscope are connected to the mass block anchor points of the two of the MEMS gyroscope are connected to the mass block anchor points of the two groups groups of driving frequency adjustment structures through the driving spring assembly of driving frequency adjustment structures through the driving spring assembly in this in this paper
The external environment disturbance can be conducted into the gyroscope chip through the inertial measurement unit (IMU), and into the resonator, which brings the change of the internal physical structure of the resonator

Summary

Introduction

In an effort to boost the product’s performance, the research mainly focused on the following three aspects of gyroscope design, combination environmental protection, and system-level calibration: Micromachines 2021, 12, 151. (3) For system-level calibration, the gyroscope noise can be lowered by the mutual whose non-orthogonal term will lead to the drift of the gyroscope signal; (3) the asymmetry calibration of two-axis MEMS gyroscopes with parallel redundant configuration in the Micromachines 2021, 12, 151 effect on the gyroscope arising from frequency split and damping split; (4) the change of resonator structure parameters caused by the environmental stress.

Design

Anti-Interference Design of External Environment

Self-Calibration

Results

Allan variance curves of the sixsix theIMU