A Dynamic Attitude Measurement System Based on LINS

Sensors

Hanzhou Li³  Quan Pan³  Xiaoxu Wang³  Juanni Zhang²  Jiang Li¹ 

[1] Northwest Institute of Mechanical & Electrical Engineering, Xian Yang 712099, China; E-Mail:;The Sixteenth Research Institute of CASC, Xi'an 710100, China; E-Mails:;School of Automation, Northwestern Polytechnical University, Xi'an 710072, China; E-Mails:

关键词: laser inertial navigation system;    attitude reference;    dynamic attitude measurement;    coning error;    time synchronization;    phase compensation;   

DOI  :  10.3390/s140916082

来源: mdpi

【 摘 要 】

A dynamic attitude measurement system (DAMS) is developed based on a laser inertial navigation system (LINS). Three factors of the dynamic attitude measurement error using LINS are analyzed: dynamic error, time synchronization and phase lag. An optimal coning errors compensation algorithm is used to reduce coning errors, and two-axis wobbling verification experiments are presented in the paper. The tests indicate that the attitude accuracy is improved 2-fold by the algorithm. In order to decrease coning errors further, the attitude updating frequency is improved from 200 Hz to 2000 Hz. At the same time, a novel finite impulse response (FIR) filter with three notches is designed to filter the dither frequency of the ring laser gyro (RLG). The comparison tests suggest that the new filter is five times more effective than the old one. The paper indicates that phase-frequency characteristics of FIR filter and first-order holder of navigation computer constitute the main sources of phase lag in LINS. A formula to calculate the LINS attitude phase lag is introduced in the paper. The expressions of dynamic attitude errors induced by phase lag are derived. The paper proposes a novel synchronization mechanism that is able to simultaneously solve the problems of dynamic test synchronization and phase compensation. A single-axis turntable and a laser interferometer are applied to verify the synchronization mechanism. The experiments results show that the theoretically calculated values of phase lag and attitude error induced by phase lag can both match perfectly with testing data. The block diagram of DAMS and physical photos are presented in the paper. The final experiments demonstrate that the real-time attitude measurement accuracy of DAMS can reach up to 20″ (1σ) and the synchronization error is less than 0.2 ms on the condition of three axes wobbling for 10 min.

【 授权许可】

CC BY   
© 2014 by the authors; licensee MDPI, Basel, Switzerland.