基于等效陀螺的捷联惯导快速两位置对准仿真

Simulation of Fast Two-Position Alignment of SINS Based on Equivalent Gyro

研究优化惯导系统的可观性能,提高捷联惯导两位置对准的速度,有助于提高导航的准确性和快速性,将水平速度误差和等效陀螺误差作为系统观测量,提出采用静基座下快速两位置对准的新方法。在常规对准方法的基础上,建立了引入陀螺信息的观测方程,用奇异值分解方法分析了新系统可观测性,推出了第一位置可观测量的最优估计及估计误差。根据状态快速收敛的特性,提出采用PCWS方法,对加速度计和陀螺进行了有效的标定,并进行了仿真,结果证明方法有效提高加快了两位置对准的速度,能充分利用陀螺信息,有效提高了惯导系统的可观测性,缩短对准时间,具有重要的参考价值。

To improve the speed of two-position alignment of SINS,a fast two-position alignment method under stationary base was presented using the level speed error and equivalent gyro error as system observation.By analyzing conventional alignment method,the observation equation with gyro information was built.Next the new system＇s observability was analyzed by using singular value decomposition method,and then the optimal estimation and estimated error of observable states at first position were deduced.According to the characteristics of fast convergence of these states,a fast two-position alignment program was proposed,and then the degree of observablity of all states in whole process was analyzed by PCWS,and the gyroscopes and accelerometers were calibrated effectively.Finally,the computer simulation results show that this method is effective to accelerate speed of two-position alignment.It takes full advantage of gyro information,to improve the system observability effectively and reduce the alignment time greatly with great reference value.