Transfer Alignment Technology Of MEMS Integrated Navigation System For Aircraft

Integrated navigation system Constituted by strapdown inertial navigationsystem based on micro electro mechanical system technology and global positioningsystem has the advantages of low cost, small volume and light quality etc. As a keytechnology of navigation system, transfer alignment technology directly influencesthe work accuracy of navigation system. In this paper, with the applicationbackground of airborne missile, in order to solve the problem of low alignmentaccuracy and long alignment time of airborne transfer alignment ofMEMS-SINS/GPS integrated navigation system, some key techniques of transferalignment such as airborne error modeling and its observability analysis, transferalignment matching method, the design of nonlinear filter were researched. The maincontents are as follows:(1)The establishment of airborne transfer alignment error model of MEMSintegrated navigation system and its observability analysis. After the introduction ofvarious coordinate for the system modeling of transfer alignment,using classicalsmall angle assumption,the linear error model of transfer alignment was established;in order to get the inertial devices error term in the filter of transfer alignment, therandom error model of MEMS inertial device was established.Then,the establishederror model of transfer alignment was analyzed with piece-wise linear constantsystem observability analysis method.(2)The research on the measurement parameter matching, parameter calculation and combined parameter matching of transfer alignment method. For the traditionalsingle parameter matching method, the advantages and disadvantages of variousmatching method were summarized through the digital simulation analysis.According to the features of airborne application background, the velocity integralmatching method proved to be optimal by Comparison. For the combined parametermatching method, the simulation results show that the velocity plus attitudematching rapid transfer alignment method has the best accuracy and rapidity.(3) Aiming at the nonlinear problem of transfer alignment error model in thelarge misalignment angle, the nonlinear error model of transfer alignment wasestablished, and analyzed by the extended kalman filter and the unscented kalmanfilter. The results show that, UKF compared with EKF, the filtering precision isimproved by more than46%, the alignment time is reduced by17%.(4)The principle prototype of transfer alignment system was developed, andthrough the experiment in a sports car, the accuracy index of airborne transferalignment technology of MEMS integrated navigation system was verified.Theexperiment also proved the effectiveness of solving the problem of matching methodand nonlinear filtering of airborne transfer alignment in this paper. The experimentalresults show that, after26s of alignment time, the error precision of roll angle, pitchangle and heading angle are respectively0.07°,0.19°and0.48°.In this paper, through theoretical research, digital simulation and car test toMEMS integrated navigation system airborne transfer alignment process, therapid transfer alignment technology for airborne MEMS integrated navigationsystem was got,and the airborne transfer alignment system principle prototype wasdeveloped. The research result is valuable to engineering application in the field ofnavigation.