组合导航系统初始对准的稳定性分析及其控制

针对INS/GPS组合导航系统的初始对准问题 ,对该组合系统的稳定性进行了理论分析和仿真研究。理论分析表明 ,该系统是稳定的 ;仿真结果说明 ,载体在外部周期激励作用下 ,如系统采样频率选择不当 ,状态变量的估计结果也出现周期性的振荡 ;如果是外部随机脉冲激励 ,状态变量的估计结果则呈现随机性。对于外部周期激励 ,采用改变采样频率或适当的线性状态反馈 ,可以较好的避免状态变量估计结果的振荡 ,满足对估计结果的精度要求。

Stability and Its Control in Initial Alignment of Integrated INS/GPS System

Initial alignment of inertial navigation system is very important. In this paper, the nonlinear error model of the inertial navigation system and its stability are presented, the state estimations of Kalman filtering is oscillating on the condition of external periodic disturb. Some simulations indicate that if the sampling frequency of system is adopted adequately, or linear states feedback is applied in the system, the periodic oscillation will be avoided. By contraries, it will come forth chaos problems. In addition, the state estimations of Kalman filtering is stochastic on the condition of external random pulse disturbance.