基于方位旋转调制的平台式惯导系统“一点校”

One-point comprehensive calibration in gimbaled inertial navigation system based on azimuth rotating modulation technique

为了提高惯导系统长时间导航精度,需要在导航阶段对系统进行综校。设计了一种基于方位旋转调制技术的平台式惯导系统一点校方案。方位旋转调制技术可以有效地调制水平惯性敏感元件误差,降低其对系统工作精度的不利影响,这为"一点校"方案的实施提供了前提。分析了方位旋转式平台惯导系统的误差模型,得到了系统误差与误差源之间的解析关系。通过分析研究系统的误差传播特性,建立了方位陀螺漂移与系统位置误差的数学模型,完成了方位旋转式平台惯导系统的"一点校"方案设计,通过系统试验验证其有效性,方位陀螺常值漂移为0.003(°)/h的条件下,经10 h一点校,40 h一点校后,72 h定位误差小于1nmile,航向误差小于1′。

To improve the precision of inertial navigation system during long time operation, the comprehensive calibration method needs to be used in the navigation stage. In this paper, a one-point comprehensive calibration scheme based on azimuth rotating modulation technique is designed to calibrate the gimbaled inertial navigation system. The azimuth rotating modulation technique can effectively modulate the errors of level Inertial Measurement Unit, thus suppress the adverse effect to the navigation precision, which provide the precondition for designing the one-point comprehensive calibration. The error model of the azimuth rotating Gimbaled Inertial Navigation System is analyzed, and the analytic expressions of the navigation errors are deduced. By analyzing the propagation characteristics of the system errors, the mathematical models of the azimuth gyro drift and the system position error are built, and the design of the proposed one-point comprehensive calibration scheme is realized. Experiment results verify the effectiveness of the scheme. Under the condition that the constant drift of the azimuth gyro is 0.003（°）/h, the position error and the heading error in 72h are less than 1nmile and 1′, respectively, after conducting the 10 h one-point calibration and the 40 h one-point calibration.