Due to the error of the inertial navigation was augmented following the time postpone . it cannot be used for long period navigation . so it cannot be used as a navigation system singleness , it must be auxiliared by the other navigation system 惯导系统由于其误差具有随时间积累效应,对于短时间内具有较高的导航精度,而不适于长时间工作的特点,因此为了弥补其不足早期各类组合导航算法也就相继产生。
In order to start ins calculate in the navigation mode the initial parameters of the transformation matrix c _ ( b ) ~ ( n ) are needed . the determination of above parameters is called as an ins alignment . the alignment of strapdown system is similar to the local - level platform system 初始对准在捷联惯导系统的研制与应用中是一个关键的问题，因为对于一个纯惯性系统来讲，其导航精度不可能优于对准误差所限定的精度。
First , theory analysis and simulation is carried through for researching one - dimensional motion . then , three - dimensional motion is simulated to get the influence of time delay to navigation computing , so does the improvement of signal bandwidth to navigation accuracy 首先在一维运动条件下进行理论分析和仿真验证,然后对于三维运动进行仿真分析,总结出时间延迟对导航计算的显著影响,以及信号带宽对导航精度的改善作用。
The integrated kalman filter method is applied to vehicle navigation system in order to revise the error of ins , study a method of refraining filter divergence in order to improve filter accuracy . the federated filter is applied to the system in order to realize the failure detection and isolation and the question of information distribution . the adaptive filter is applied to the system in order to solve the question of inaccuracy or unknown noise statistics and to make navigation accuracy increase 在gps / ins车辆组合导航中，应用集中式卡尔曼滤波算法校正ins的误差，研究了抑制滤波发散的方法，提高了滤波精度；应用联邦滤波实现了gps / ins的信息融合与信息分配，解决了当gps发生故障时的故障检测与隔离问题；应用自适应滤波解决了实际中噪声统计特性不准确或未知的问题，提高了导航精度。
In this paper , the main research works are as follows : 1 ) survey and analysis previous work in auv navigation and summarize : as the cumulate error , the dead - reckoning and inertial navigation systems ca n ' t be used without other modified system ; the acoustic navigation system is used only in small range , and is very expensive . 2 ) two important approaches in geophysical navigation techniques are summarized , one is terrain contour based navigation , this approach is investigated keystone today ; the other is image based navigation , due to no perfect image sensors and image seabed map , this approach has seldom been practised . 3 ) two important terrain contour based navigation algorithms has been applied to auv , one is match algorithm - based terrain contour match ( tercom ) ; the other is kalman filter - based sandia inertia terrain - aided navigation ( sitan ) 主要研究内容包括：一、总结分析了当前水下导航的常用方法和不足之处，指出基于航位推算的导航方法，存在着最大的问题就是导航误差的积累问题，如果没有修正系统，这种方法很难满足使用要求；其次指出基于声学的导航方法，造价昂贵，导航范围有限，难以满足自主水下航行器大范围导航的需求；二、总结了当前水下地形辅助导航的主要技术路线，一是基于地形高程的匹配方法，这是当前研究的重点；二是基于地形图像的匹配方法，由于缺乏良好的图像传感器，和可用的海底图像地图，目前这种方法还有待研究发展；三、将两种地形高程匹配的常用方法应用到自主水下航行器上：以相关算法为前提的地形轮廓匹配( tercom )方法和以卡尔曼滤波为基础的桑迪亚惯性地形辅助导航( sitan )方法，前者算法简单可靠，但是导航精度不高，后者虽然精度比较高，但存在着算法较为复杂、有可能发散和出现奇异值等问题。
The scrolling error in the position updating calculation is discussed and the scrolling error compensation algorithms are studied in the sculling base motion environment . the simulations of the algorithms are performed and the results show that the scrolling correction term should be considered to improve the position accuracy for the system with high - resolution position updating requirements 分析了位置更新计算中涡卷误差的产生机理，研究了划船运动条件下的涡卷补偿优化算法，并对算法的性能进行了仿真分析，结果表明：对于导航定位精度特别高的场合，应该考虑加入适当的涡卷补偿来提高导航精度。
Use the magnetic vector for the observation information , the paper estimate the location and rate of the satellite , analysis of simulation results and the sources of error . to further enhance navigation accuracy , the paper study the unscented kalman filter , compare with the extend kalman filter . in the same initial conditions of the extend kalman filter , we do the simulation 其次,基于磁环境模拟系统的测量数据,本文研究了扩展卡尔曼滤波算法,建立了卫星的运动学和动力学方程,以地磁场矢量为观测信息,对卫星位置速度进行了估计,并分析了仿真结果及误差来源,为了进一步提高导航精度,本文又研究了unscented卡尔曼滤波算法,给出了原理及步骤,并与扩展卡尔曼滤波进行了比较分析。
2 ) for the rank - short problem of inter - satellite measurement net , the architecture of constellation ’ s autonomous navigation was designed . satellite - to - satellite and satellite - to - ground measurement scheme and time synchronization of measurement were discussed . last , all factors that influence the navigation precision of constellation were analyzed mathematically , and some useful conclusions were drawn 2 )针对星间观测网的秩亏问题,进行星座自主导航系统的框架设计,讨论了星间、星地的测量方案以及测量值的时间同步问题,最后对影响星座导航精度的各个因素进行了数学分析,得出了一些有益的结论。
As the cumulate error , inertial navigation system ca n ' t provide perfect position and navigation for the autonomous underwater vehicles ( auv ) in unstructured , complex and instable ocean in a long time . the application of terrain - aided navigation techniques to the updating of an inertia navigation system has been investigated 惯性导航系统是实现水下导航的一种重要方法，但惯性导航存在累计误差，为了修正惯性导航的累积误差，提高导航精度，本文将飞机、导弹等所使用的地形辅助导航系统，应用到水下航行器上，成功地满足了自主水下航行器的导航需求。
Different sampling periods of sensors and the recursive steps of initial states are investigated . the navigation precision with different condition such as different precision of sensors , different length of observation time are compared . then , three orbit types , consisting of low - altitude orbit , middle - altitude orbit and high - altitude orbit , are simulated respectively 在pc机上首先分析敏感器采样周期和滤波迭代次数对自主导航精度的影响,然后比较敏感器精度不同,观测时间长短不同,轨道类型不同情况下所产生的导航误差。
