Research Of Algorithm For Gyroscope Free Strapdown Inertial Navigation System

With the development of computer technology and inertial instrument technology,inertial navigation technology has been popularly applied in aviation, aerospace, marine, andother civilian areas. Conventional stradown inertial navigation system is not suitable forapplication in the occasion of large overload and large angular velocity. However, theall-accelerometer array consisting of navigation systems, which gyroscopes is discarded willstill get great work in the occasion of large acceleration and angular velocity, This navigationsystem has been got an extensive research, and accessed to many research results, in recentyears, it is no doubt that inertial navigation technology has already become an importantresearch direction. However, due to having been discarded gyroscopes, angular velocity isrely on the output signal of accelerometers which will be calculated, making the navigationsystem errors quickly accumulate over time, affect the navigation system’s accuracy. Thispaper makes important analysis on the solution method of the angular velocity and fusionestimation of gesture, in order to improve the accuracy of navigation systems.The main contents of this study are: firstly, through the analysis of several typical spatialconfiguration of accelerations, I use a reasonable and practical nine accelerometerconfiguration, and make more focus on angular velocity solver algorithm according to theoutput of the accelerometer. Integration method and open method is the usual algorithms ofangular velocity, the paper also gives the trim by the angular velocity error iterative solver,and use the counting method, then propose a fusion algorithms with several solution methods.Secondly, during the attitude algorithm, I made a detail analysis and simulation on themethod of quaternion and rotation vector method. Although the system is away from thegyroscope, but the error still exists in the cone system, it needs for error compensation, whensolving the speed, boating error also exists. Finally, for a short-range tactical missiles, themagnetometer is introduced to strapdown navigation system, combined with the compositionof nine accelerometers attitude determination system, the quaternion and angular velocityobtained by the accelerometer as the system state variables, The magnetometer’s output andangular velocity squared as observations, to build the state equation and observation equation,then design EKF filtering algorithm. Through simulation analysis, angular velocity andattitude error solver divergence angle error have been effectively suppressed.In this paper, the research on improving the accuracy of the angular velocity solvermethods and investigation on navigation by using geomagnetic information and accelerometer information to improve the navigation accuracy, provides a theoreticalfoundation for this whole accelerometer inertial measurement system to be practical andengineering, and also provides a reference for more in-depth study, it has a certain researchvalue and broad application prospects.