A Novel INS and Doppler Sensors Calibration Method for Long Range Underwater Vehicle Navigation

TLDR

INS drifts grow over time, so DVLs are routinely integrated with INS to constrain error, but accuracy is limited by DVL scale factor and INS–DVL misalignments. The paper proposes a novel calibration method for INS/DVL parameters. The method iteratively calibrates INS/DVL parameters, employs a simplified integration scheme, and is tested on river and sea trial data. With high‑precision sensors, the calibrated INS/DVL system achieves about 1‰ CEP in river trials and 2‰ CEP in sea trials.

Abstract

Since the drifts of Inertial Navigation System (INS) solutions are inevitable and also grow over time, a Doppler Velocity Log (DVL) is used to aid the INS to restrain its error growth. Therefore, INS/DVL integration is a common approach for Autonomous Underwater Vehicle (AUV) navigation. The parameters including the scale factor of DVL and misalignments between INS and DVL are key factors which limit the accuracy of the INS/DVL integration. In this paper, a novel parameter calibration method is proposed. An iterative implementation of the method is designed to reduce the error caused by INS initial alignment. Furthermore, a simplified INS/DVL integration scheme is employed. The proposed method is evaluated with both river trial and sea trial data sets. Using 0.03°/h(1σ) ring laser gyroscopes, 5 × 10−5 g(1σ) quartz accelerometers and DVL with accuracy 0.5% V ± 0.5 cm/s, INS/DVL integrated navigation can reach an accuracy of about 1‰ of distance travelled (CEP) in a river trial and 2‰ of distance travelled (CEP) in a sea trial.