Gyroscope Drift Error Analysis in the Position-Independent Navigation Algorithm of a stable platform Inertial System

This paper deals with analyzing gyroscope drift error in the position-independent navigation algorithm of a stable platform inertial system. Most of the stable platform navigation algorithms proposed in the literature have drawbacks of estimating position rates for alignment commands. Not only the estimating position rates are the basic source of position errors, but they also make the alignment commands and their implementation more complicated. The major advantage of the proposed design is that the angular velocity commands of gyroscopes are independent of the system position and are proportional to accelerations’ integrals, all of which eliminate, the errors resulted from the estimation of the longitude and latitude rates. In this paper, the stable platform system is modeled, and plate alignment procedure is determined and the initial conditions of navigation phase are calculated. In stationary conditions, the position error propagation for the fixed gyroscope drift is obtained analytically. The position error of the proposed algorithm propagates linearly with time, while in the strapdawn algorithm; this error propagates as the cube of time.