Track Matching Based On Depth Information And Its Application In INS

At present,with the rapid development of science and technology,human beings have entered the stage of land resources becoming increasingly scarce.Therefore,human beings have turned their eyes to the ocean which is far larger than the land area.Therefore,the exploration of marine resources has become a subject that various countries are competing to study.As one of the important tools to explore the ocean,whether the underwater vehicle can accurately navigate is the precondition for the underwater vehicle to complete the task,and is also a key research topic in the navigation field.Due to the accumulation of time,the error of the inertial navigation system becomes larger,which can not meet the requirements of navigation accuracy when the underwater vehicle is sailing for a long time,while the GPS navigation system has certain limitations when underwater navigation because the radio wave is affected by the water medium.Therefore,in this paper,we explore a method that can calibrate the inertial navigation system independently,so as to meet the task requirements of underwater vehicle precise navigation,Firstly,the terrain matching navigation system is studied deeply,and the matching algorithm based on the contour is established.Secondly,the position information obtained is combined with Kalman filter to calibrate the inertial navigation system,so that the underwater vehicle can achieve long-term and high-precision navigation to successfully complete the task.Firstly,this paper introduces the components of the underwater terrain matching navigation system,including the method of bathymetry,how to build digital terrain map,the principle of the existing algorithm of the underwater terrain matching system,and analyzes the advantages and disadvantages of each matching algorithm,then the coordinate system,the transformation between coordinate system and strapdown in the inertial navigation system The mechanical arrangement of inertial navigation system is introduced in detail,which lays the foundation for the design of matching algorithm.Then,based on the analysis of the advantages and disadvantages of each matching algorithm,the design of the matching algorithm based on the optimization of value function of depth information is carried out.The method,execution process and feasibility of the algorithm are introduced in depth.In addition,the acquisition process of the contour map is also explained.The simulation experiment of the proposed algorithm is carried out to verify the design The performance of the matching algorithm is analyzed.Because in the actual operation process,there may be some relevant factors,so the accuracy of the matching algorithm is analyzed.The single or superimposed simulation analysis is mainly carried out on the factors such as the inertial navigation system error,depth measurement error,digital map resolution and so on.It is concluded that the digital map resolution has the greatest impact on the accuracy of the algorithm.When each error has cross effect,the accuracy of the matching algorithm will also be reduced.But generally speaking,the effect of the designed matching algorithm is good.Finally,in order to achieve the goal of this project,the design of the calibration of the inertial navigation system is carried out.The error equation of inertial components and the error equation of velocity,position and attitude existing in the strapdown inertial navigation system are derived.Each filtering estimation method is introduced and compared with its advantages and disadvantages.The filtering method selected in the calibration process is determined by synchronous data fusion The integrated method solves the problem that the update time of ins and terrain matching navigation system is not synchronous.On this basis,the design of integrated navigation system and the modeling of integrated navigation system are carried out.Finally,the simulation experiment of the system is carried out to realize the correction of INS.