高精度惯导系统重力扰动的阻尼抑制方法

摘要

重力扰动已经成为高精度长航时惯导系统的主要误差源之一.针对船用高精度惯导系统的重力扰动抑制问题,从舰船INS误差模型出发,推导了重力扰动在惯导系统中的传播特性.仿真结果表明垂线偏差将引起系统较大的舒拉振荡误差.为抑制重力扰动对系统的影响,引入常速度误差反馈阻尼网络和相位超前串联阻尼网络.分析了重力扰动在水平阻尼网络中的传递特性,实现了相应滤波器的设计.在此基础上完成了实验验证,海上试验结果表明,所引入的两种阻尼网络都能够阻尼掉重力扰动引起的舒拉振荡型导航误差,其中,相位超前串联阻尼网络效果更优,抑制率达到70％以上.%The gravity disturbance is one of the main error sources of marine high-precision inertial navigation system,which is consisted of two parts:vertical deviation and gravity anomalies.The propagation characteristics of gravity disturbance in the navigation system are deduced based on the SINS error model,and the simulation results show that the vertical deviation will cause much larger Schular oscillation error than the gravity anomalies which can be ignored.Since the system error caused by the vertical deviation can be equivalent to the one caused by the bias of the accelerometer,a constant velocity error feedback network and a phase advance series damping network are introduced to suppress the gravity disturbance's influence by an autonomous method.The error transfer equation of gravity anomaly in horizontal damping circuit is deduced,and the corresponding filter design is achieved.Based on these,the sea experiments are carried out,which show that the introduced horizontal damping networks can significantly damp out the Schular oscillation errors caused by the gravity disturbance,in which the phase-advance series damping network has an even better inhibitory effect,whose inhibition rate is up to more than 70％.