A New Method to Improve the Navigation Performance of SINS in Vibration Environment

Abstract

Strap-down Inertial Navigation System (SINS) based on quartz accelerometer is widely applied in navigation fields such as ships, vehicles and aircrafts. However, the accuracy of accelerometer is degraded in vibration environment, which decreases the performance of SINS. Aiming at improving the performance of SINS, this paper proposed a new method for calibrating the second-order nonlinear coefficient of accelerometer by using the linear vibration table to generate random vibration. We call this method “the method of Calibrating Second-order nonlinear coefficient with Random Vibration (CSRV)”. A modeling method including the high-order nonlinear coefficients of accelerometer is proposed. The linear vibration table is used to generate high-g random vibration, which can excite the second-order nonlinear coefficient of accelerometer. Therefore, the second-order nonlinear coefficient can be accurately calculated via the static and dynamic output of accelerometer. Vibration tests were performed for accelerometer. Experimental results indicate that the second-order nonlinear coefficients of three accelerometershave good repeatabilityof 8.96×10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-6</sup> g/g <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> in the test environment less than 3.34g and can be compensated. Vibration tests for further verification are performed using the SINS. Experimental results show that the Circular Error Probable (CEP) can be reduced by 38.8% with the second-order nonlinear coefficient compensated. In conclusion, the proposed method of navigation performance improvement are effective and feasible, and can significantly improve the navigation performance of SINS in vibration environment.