Research On Large Range UUV Underwater Navigation Calibration Based On UTP

In recent years,world maritime disputes have continued.In order to safeguard national maritime sovereignty and vital interests,the Unmanned Underwater Vehicle(UUV),as a platform for carrying underwater operating equipment,has played a pivotal role in the civilian and military fields..In order to achieve accurate position estimation of UUV,the widely used inertial navigation method needs to be calibrated due to the impact of cumulative errors.This article focuses on the UUV’s use of Underwater Transponder navigation.The main contents are as follows:First,this article introduces the principle of traditional single beacon navigation.According to the different types of information used in single beacon navigation,based on the Direction of Arrival(DOA)and Time of Arrival(TOA))And the single beacon navigation model principle of Time Difference of Arrival(TDOA)are introduced.The partial differential matrix method combined with the HDOP factor is used to analyze the navigation error distribution.Secondly,for the single beacon navigation method based on Doppler information,this paper analyzes the principle of Frequency Difference Of Arrival(FDOA)navigation technology in the traditional radio field,and concludes that it has low angle measurement accuracy in underwater environments.in conclusion.In this regard,this paper proposes an improved FDOA navigation method for the underwater environment.Under the condition that the UUV depth is known,the method uses envelope alignment,conjugate multiplication,and linear fitting of the arrival signal to obtain the phase angle change rate information,thereby solving the position of the UUV itself.According to the simulation results,compared with the single beacon navigation method based on the time delay difference and the azimuth information,the navigation method effectively improves the accuracy of the UUV position calculation.In order to further analyze the observability of the model,the observability analysis of the model was performed using Lie derivatives,and the observable area in space by UUV using the proposed model was obtained.In order to improve its own navigation accuracy through multiple measurements,a navigation tracking model based on the improved FDOA method is established in this paper,combining two algorithms of unscented Kalman filter and unscented particle filter.Navigation calibration results under typical routes,the results show that both methods can effectively and quickly calibrate the UUV position,and the results of circular routes are better than straight routes.Finally,in order to solve the problem of UUV using a single beacon navigation model with improved FDOA method to achieve large-scale navigation calibration,this article analyzes the situation of maintaining different elevation differences between UUV and beacons,the same depth,different vector diameter AB,and different chordal center distances.To ensure that the UUV finally enters the circular calibration path around the beacon,this article designs an approach route that guides the UUV into the circular calibration path.A large-scale UUV navigation calibration process was designed and simulation experiments were performed.At a distance of 750 km,three beacons were deployed and the inertial navigation error calibration of UUV was achieved by using the improved FDOA navigation method.