Online Calibration Method of DVL Error Based on Real-Time Deformation Compensation

This article presents a novel online calibration technique for Doppler velocity log (DVL) error that utilizes real-time deformation compensation. The technique aims to address the issue of degraded combined navigation accuracy in strap-down inertial navigation system/DVL (SINS/DVL) integrated navigation system caused by the changes in the installation relationship between the two systems during operation. By measuring the real-time deformation angle of the SINS and DVL installation, the online calibration enhances the accuracy of the combined navigation in SINS/DVL. The proposed approach consists of several key steps. First, a model is established to represent the deformation angle of the DVL and SINS installation based on the inertial matching principle. Second, the dynamic observation equation for SINS/DVL installation error is derived. Subsequently, a real-time Kalman filter (KF), based on velocity matching, is developed to calculate and compensate for the SINS/DVL installation error. Finally, a comprehensive sea trial is conducted to validate the effectiveness of the proposed method. The test results demonstrate that the proposed technique improves the navigation accuracy of the SINS/DVL combination by 80% compared to the original method, particularly in scenarios involving mounting deformation angles between the DVL and SINS.