测量信号随机延时下的捷联惯导系统.doc
约67页DOC格式手机打开展开
测量信号随机延时下的捷联惯导系统,摘要初始对准是惯性导航系统的关键技术之一，对准的精度直接影响惯导系统的工作性能。滤波技术在初始对准中具有极其重要的作用，对系统精度具有至关重要的影响。实际的惯导系统尤其是捷联惯导系统，由于工作环境非常恶劣，同时又受到外部各种因素的干扰，其初始失准角往往比较大，误差模型呈现非线性，因此需要非线性的滤波方法，而且在使用滤波...
内容介绍
此文档由会员 违规屏蔽12 发布
摘 要
初始对准是惯性导航系统的关键技术之一，对准的精度直接影响惯导系统的工作性能。滤波技术在初始对准中具有极其重要的作用，对系统精度具有至关重要的影响。
实际的惯导系统尤其是捷联惯导系统，由于工作环境非常恶劣，同时又受到外部各种因素的干扰，其初始失准角往往比较大，误差模型呈现非线性，因此需要非线性的滤波方法，而且在使用滤波方法进行初始对准时，存在着观测数据延时的情形，并且由于系统的随机性，观测信号出现延时的可能性也是随机的。因此研究观测信号随机延时下的非线性滤波方法，并将其应用于捷联惯导系统的初始对准，进一步提高系统性能，具有十分重要的意义。
本文对观测信号随机延时下的捷联惯导系统初始对准进行了研究，在建立观测信号随机一步延时模型的基础上，推导了非线性离散系统观测信号随机一步延时的扩展滤波和Unscented滤波方法，并将其应用于捷联惯导系统动基座初始对准中。
本文的主要研究工作和成果可归纳如下：
(1) 阐述了捷联惯导系统初始对准基本原理及捷联惯导系统误差产生的原因，详细推导了惯性传感器误差模型，速度误差方程，姿态误差方程和位置误差方程。
(2) 建立了带加性噪声的非线性离散随机系统观测信号随机一步延时的非线性模型，讨论了其滤波问题，推导了基于线性化系统方程的扩展滤波方法，给出了其滤波方程。
(3) 在介绍UT理论、UT采样策略的基础上，推导了基于SUT的观测信号随机一步延时的Unscented滤波方法，并采用SSUT对Unscented滤波方法进行改进，得到了基于SSUT的SSUF滤波方法。
(4) 建立了捷联惯导系统大方位失准角下动基座非线性对准模型，包括系统状态方程和观测信号随机一步延时的系统观测方程，将扩展滤波方法和Unscented滤波方法应用于初始对准中，对滤波算法进行仿真对比，实验结果表明，Unscented滤波方法具有更高的对准精度和更快的收敛速度，Unscented滤波的改进算法与Unscented滤波精度相当，但是计算量大大降低。
关键词 观测值随机延时；扩展卡尔曼滤波；Unscented卡尔曼滤波；捷联惯导系统；初始对准
Abstract
Initial alignment is one of the key technologies of the inertial navigation system, it’s alignment accuracy directly affect the navigation system working performance. Filtering technique plays an extremely crucial role in the initial alignment and has an important effect to the system accuracy.
Actual inertial system always works in rugged environment and often suffers interferences from various kinds of fators. Especially to the strap-down inertial navigation system (SINS), the intial heading error angle is relatively large and the error model is generally nonlinear. The nonlinear error model needs nonlinear filtering methods. In SINS initial alignment, there exist situation in which the arrival of the measured data is delayed and due to the system of uncertainty, the possibility of delay in each measurement is random. Therefore, it is very significant to research the nonlinear filtering methods using randomly delayed observations and it’s application in SINS initial alignment in roder to improve the system performance.
In this paper, SINS initial alignment with randomly delayed observations is researched. On the base of establishment of the model with one-step randomly delayed observations, Extended Filter and Unscented filter for nonlinear discrete-time systems using one-step randomly delayed observations contaminated by additive white noise are developed and are applied to initial alignment of SINS.
The main research work in this thesis can be summarized as follows:
Firstly, the basic theory of SINS initial alignment and the causes of SINS error are expatiated. The inertial sensor error models, velocity error equations, attitude error equations and position error equations of SINS are given respectively.
Secondly, the nonlinear model of nonlinear discrere-time stochasic system using observations with stochastic delays contaminated by additive white noise is established and it’s filtering promble is discussed. The Extended Filter (EF) based on linearizing system equations is derived and it’s filtering equations are given.
Thirdly, on the base of Unscented Transform (UT) theory and UT sampling strategy, Unscented Filter (UF) using one-step randomly delayed observations is derived and improved Unscented Filter based on SSUT is investigated.
Fourthly, the nonlinear alignment model of SINS on moving bases is established, including system state equation and system observation equation using one-step randomly delayed observations. The EF and UF are applied and simulated to initial alignment of SINS. The simulation results show that the UF has faster convergent rate and better aligment precision than EF. Improved filtering has the same aligment precision with UF and it’s computions are greatly reduced.
Key words randomly delayed observations; EFK; UKF; SINS; initial aligment
目 录
摘 要 I
Abstract III
第1章 绪论 1
1.1 研究背景与意义 1
1.2 初始对准技术的发展 2
1.3 滤波理论的发展 3
1.4 本文研究的主要内容 5
第2章 捷联惯导系统初始对准基本原理 7
2.1捷联惯导系统概述 7
2.1.1常用坐标系的定义 7
2.1.2捷联惯导系统工作原理 8
2.2 捷联惯导系统初始对准 9
2.2.1 初始对准的特点 10
2.2.2 初始对准的分类 10
2.2.3 初始对准的原理 11
2.3 本章小结 ..
初始对准是惯性导航系统的关键技术之一，对准的精度直接影响惯导系统的工作性能。滤波技术在初始对准中具有极其重要的作用，对系统精度具有至关重要的影响。
实际的惯导系统尤其是捷联惯导系统，由于工作环境非常恶劣，同时又受到外部各种因素的干扰，其初始失准角往往比较大，误差模型呈现非线性，因此需要非线性的滤波方法，而且在使用滤波方法进行初始对准时，存在着观测数据延时的情形，并且由于系统的随机性，观测信号出现延时的可能性也是随机的。因此研究观测信号随机延时下的非线性滤波方法，并将其应用于捷联惯导系统的初始对准，进一步提高系统性能，具有十分重要的意义。
本文对观测信号随机延时下的捷联惯导系统初始对准进行了研究，在建立观测信号随机一步延时模型的基础上，推导了非线性离散系统观测信号随机一步延时的扩展滤波和Unscented滤波方法，并将其应用于捷联惯导系统动基座初始对准中。
本文的主要研究工作和成果可归纳如下：
(1) 阐述了捷联惯导系统初始对准基本原理及捷联惯导系统误差产生的原因，详细推导了惯性传感器误差模型，速度误差方程，姿态误差方程和位置误差方程。
(2) 建立了带加性噪声的非线性离散随机系统观测信号随机一步延时的非线性模型，讨论了其滤波问题，推导了基于线性化系统方程的扩展滤波方法，给出了其滤波方程。
(3) 在介绍UT理论、UT采样策略的基础上，推导了基于SUT的观测信号随机一步延时的Unscented滤波方法，并采用SSUT对Unscented滤波方法进行改进，得到了基于SSUT的SSUF滤波方法。
(4) 建立了捷联惯导系统大方位失准角下动基座非线性对准模型，包括系统状态方程和观测信号随机一步延时的系统观测方程，将扩展滤波方法和Unscented滤波方法应用于初始对准中，对滤波算法进行仿真对比，实验结果表明，Unscented滤波方法具有更高的对准精度和更快的收敛速度，Unscented滤波的改进算法与Unscented滤波精度相当，但是计算量大大降低。
关键词 观测值随机延时；扩展卡尔曼滤波；Unscented卡尔曼滤波；捷联惯导系统；初始对准
Abstract
Initial alignment is one of the key technologies of the inertial navigation system, it’s alignment accuracy directly affect the navigation system working performance. Filtering technique plays an extremely crucial role in the initial alignment and has an important effect to the system accuracy.
Actual inertial system always works in rugged environment and often suffers interferences from various kinds of fators. Especially to the strap-down inertial navigation system (SINS), the intial heading error angle is relatively large and the error model is generally nonlinear. The nonlinear error model needs nonlinear filtering methods. In SINS initial alignment, there exist situation in which the arrival of the measured data is delayed and due to the system of uncertainty, the possibility of delay in each measurement is random. Therefore, it is very significant to research the nonlinear filtering methods using randomly delayed observations and it’s application in SINS initial alignment in roder to improve the system performance.
In this paper, SINS initial alignment with randomly delayed observations is researched. On the base of establishment of the model with one-step randomly delayed observations, Extended Filter and Unscented filter for nonlinear discrete-time systems using one-step randomly delayed observations contaminated by additive white noise are developed and are applied to initial alignment of SINS.
The main research work in this thesis can be summarized as follows:
Firstly, the basic theory of SINS initial alignment and the causes of SINS error are expatiated. The inertial sensor error models, velocity error equations, attitude error equations and position error equations of SINS are given respectively.
Secondly, the nonlinear model of nonlinear discrere-time stochasic system using observations with stochastic delays contaminated by additive white noise is established and it’s filtering promble is discussed. The Extended Filter (EF) based on linearizing system equations is derived and it’s filtering equations are given.
Thirdly, on the base of Unscented Transform (UT) theory and UT sampling strategy, Unscented Filter (UF) using one-step randomly delayed observations is derived and improved Unscented Filter based on SSUT is investigated.
Fourthly, the nonlinear alignment model of SINS on moving bases is established, including system state equation and system observation equation using one-step randomly delayed observations. The EF and UF are applied and simulated to initial alignment of SINS. The simulation results show that the UF has faster convergent rate and better aligment precision than EF. Improved filtering has the same aligment precision with UF and it’s computions are greatly reduced.
Key words randomly delayed observations; EFK; UKF; SINS; initial aligment
目 录
摘 要 I
Abstract III
第1章 绪论 1
1.1 研究背景与意义 1
1.2 初始对准技术的发展 2
1.3 滤波理论的发展 3
1.4 本文研究的主要内容 5
第2章 捷联惯导系统初始对准基本原理 7
2.1捷联惯导系统概述 7
2.1.1常用坐标系的定义 7
2.1.2捷联惯导系统工作原理 8
2.2 捷联惯导系统初始对准 9
2.2.1 初始对准的特点 10
2.2.2 初始对准的分类 10
2.2.3 初始对准的原理 11
2.3 本章小结 ..
