| At the bottom of the unknown complicated seabed environment, at present human knowlittle about the bottom environment of the sea. Because we cannot put the ransducer ortransducer array into the unknown sea area in advance, also we cannot get accurateenvironment surveying diagram in advance, so the acoustic navigation methods andgeophysical navigation methods cannot be used. Due to the particularity and complexity ofthe underwater navigation, the SINS （Strapdown Inertial Navigation System） play animportant role in the underwater navigation. The underwater navigation system of the AUVusually takes SINS as the core, supplemented by the GPS and DVL to constitute theintegrated navigation system, so we can give full play to the advantages of each navigationmethods, so as to improve the reliability, stability and accuracy of the navigation system. Themain research content in this paper is divided into two parts, and the first part for the range ofthe DVL underwater navigation is not enough, respectively designing the surface andunderwater integrated navigation mode, through the establishment of current model toestimate the current speed,and improve the navigation accuracy. The second part analyse theimpacting which caused by the changing of the ship position, acceleration and velocity on themoving base compass circuit alignment accuracy, by introduced the DVL auxiliary, and wepromote the compass circuit alignment methods from the static base to the moving basesituation, the main work of the paper as follows:Introduce the basic knowledge of the SINS, define the coordinate system used in thenavigation and introduce the mathematical transformation methods between the coordinatesystem, and deduce the basic equation of the SINS. In view of the errors of the system willgive a great influence on navigation accuracy, we focus the point on the establishment of theerror model of the SINS, finally we introduce the initial alignment technology of the SINS.For the range of the DVL underwater navigation not enough, the underwater navigationsystem of the AUV takes SINS as the core, through establishing the current model, and wedesign the surface SINS/GPS/DVL and the underwater SINS/DVL integrated navigationsystem mode, in this way we can estimate the current speed with the kalman filteringalgorithm. We improve the the navigation accuracy caused by the DVL range not enough, andthrough the simulation results, the current compensation can verify the feasibility of the integrated navigation scheme.As the speed measurement device, DVL can provide stable and continuous speedinformation, and DVL is an important part of the integrated navigation system, so the researchon the speed error compensation technology of the DVL is very meaningful. When the shipnavigates on the surface of the sea, the DVL speed error is mainly affected by the interferenceof the wind swing, if we compensate the DVL speed error in the measurement equation, theintegrated navigation accuracy can be improved.In order to promote the compass circuit alignment methods from the static base to themoving base situation, we research the impacting which caused by the changing of the shipposition, acceleration and velocity on the moving base compass circuit alignment accuracy,and obtain the improvement methods for the static base compass alignment, then we presentthe DVL speed auxiliary for the moving base compass alignment methods, and successfullypromote the compass circuit alignment methods from the static base to the moving basesituation. |
