Research On SINS/DVL Integrated Navigation System Based On M Estimation

This thesis mainly studies the integrated navigation system of water or surface navigation,Strapdown inertial navigation system(SINS)and Doppler navigation system(DVL),SINS system and DVL system information fusion method by Kalman filter,in order to correct the error strapdown inertial navigation system with time accumulation,but the SINS/DVL integrated navigation system in the process of working for a variety of reasons can sometimes be observed outliers,which will have a great influence on the process of filtering,may even lead to filter divergence,aiming at this problem,put forward the M estimation methods to weaken or eliminate the effect of outliers on the filtering process.First of all,this paper introduces the inertial navigation system in detail,and introduces the realization of the coordinate system and the coordinate transformation between the coordinates in the Strapdown inertial navigation system.Then the mechanics of Strapdown inertial navigation system arrangement equations are derived,and on this basis,the nonlinear error model of Strapdown inertial navigation system is deduced,and then the working principle and error of the Doppler navigation system model were deduced in detail,on this basis,deduced the state error equations of Strapdown inertial navigation system and Doppler system,and construct the filter model of SINS/DVL integrated navigation system.Details of the classic Kalman filter algorithm,extended Kalman filter algorithm,unscented filtering algorithm and the volume of Kalman filtering algorithm principle,and the three methods were compared by the method of filtering principle.Then,the definition of wild value is given,and the reason and inevitability of wild value are analyzed.In view of this influence is put forward a method of M estimation is added to the process of Kalman filter,through detailed formulas to illustrate the principle of the M estimation and its inhibition of the principle of outliers and M estimation,are applied to nonlinear filtering method in different M estimation is not suitable for the analysis of different filter methods.For the navigation of SINS/DVL integrated navigation system for the measurement process,whether there are two kinds of outliers,respectively using different filtering algorithm to filter through the simulation experiment,the simulation results to verify the existence of outliers will affect the filtering process,then add M estimator in the different filtering algorithm.And then filtering simulation experiments by simulation result analysis after joining the M estimator have obvious inhibitory effect on the outliers.