.sins / Gps Integrated System Flight Alignment

In this paper, the problem of SINS/GPS integrated navigation system's flight alignment, which is to be used on guidance shell, is studied, designed and stimulated.Fist we studied the mechanics arrange equation and error equation of SINS, analyzed the error source model of gyro and accelerator, so we have established the error model of SINS. Then we introduced the operational principal of GPS briefly, studied its capture model, solved the position and velocity information by a linearization algorithm, and established the GPS' error model.We stressed the design of algorithm for SINS/GPS integrated system's flight alignment in this paper. The integrated system is composed of SINS and GPS, each subsystem's navigational parameter is sent to navigation computer. At there the azimuth and attitude angle error is estimated by Kalman filter, then be used to adjust the attitude matrix of SINS.The integrated system uses two different integrated modes: one is loose integrated mode by using position and velocity parameters, the other is deep integrated mode by pseudo range and pseudo range rate. The innovation shows in:1. During the design of algorithm, we advised to increase the GPS' output rate by dead reckoning so as to decrease the filtering period, and corrected the quaternion at the initial phase of filter. These methods can improve the quickness and accuracy of alignment efficiently.2. During the select of adjust mode, we chosen the feedback mode, because SINS has to work solely before the capture of satellite signal, the initial error is considerable at the beginning phase. The feedback adjust mode can enhance the degree of approximation of SINS' error equation, consequently improve the system's accuracy.3. When the filter is worked under deep integrated mode, we used the Potteralgorithm of square root filter to avoid calculate disperse, which is conduced by the accumulate of round off error. So we enhanced the system's robustness.At the end of this paper we stimulated the designed arithmetic, including shell aviation track stimulation, pure SINS system stimulation, GPS system stimulation, and Kalman filter arithmetic stimulation under different mode. The result indicates, under the condition of big initial error and shell's high speed rolling, after 60 seconds' flight alignment, the error of azimuth angle and attitude angle can be decreased to no more than 10 angle second, and the position and velocity error has been corrected. This shows the effective of our designed arithmetic.