初始对准误差对惯性制导误差影响的简化算法

惯性制导系统初始对准的主要任务是精确确定载体坐标系和制导坐标系之间的初始方向余弦矩阵和载体的初始速度。惯性制导的精度在很大程度上取决于系统初始对准的精度。本文基于初始对准误差引起的惯性导航误差模型,针对近程战术武器系统,在一定精度范围内,忽略引力变化和发射时载体的初始速度,推导出初始对准误差对惯性制导误差影响的简化算法。该算法具有模型清晰,计算简便,易于使用的特点,避免了繁琐的运动学建模和编程计算过程,并且为在项目论证阶段不具备完备的总体数据支持的条件下,进行初始对准精度指标分配提供了理论依据。并经仿真验证,简化算法具有一定的精度。     

纬度未知条件下捷联惯导系统初始对准分析

在捷联惯导系统静基座初始对准的传统方法中,一般要求准确知道当地的地理纬度,如果给定的纬度存在误差,将可能影响初始对准精度。在静基座条件下并且地理纬度未知时,研究捷联惯导系统的初始对准实现问题,并对初始对准精度作详细分析。研究结果表明,在静基座条件下,借助于捷联惯组中的陀螺和加速度计的测量值可以估计出对准点处的地理纬度,再利用估计纬度进行初始对准,如果选择初始对准算法适当,纬度估计误差将不会影响对准精度。     

一种新的基于姿态四元数匹配的传递对准方法

设计了一种新的姿态四元数匹配传递对准方法,并以载机姿态四元数与弹体姿态四元数的四元数乘积作为量测量,推导了姿态四元数匹配量测方程。通过理论分析,得出了载机平台失准角、弹体平台失准角、弹体安装误差角和机翼颤振变形角为小量的情况下,这些量与量测量之间的关系。推导了传统的姿态角匹配传递对准方法量测方程,与之相比,姿态四元数匹配量测方法明显降低了计算量,并分别对两种姿态匹配方法进行了仿真,仿真结果表明：新的姿态四元数匹配方法与传统姿态匹配传递对准方法具有相同的精度。     

“速度积分”匹配传递对准方法研究

传递对准时,飞机机翼的弹性变形会对挂在机翼上导弹的子惯导系统的对准精度产生很大的影响。本文研究了"速度积分"匹配传递对准方法,通过与速度匹配和"速度+姿态"匹配方法的仿真结果进行比较得出以下结论:"速度积分"匹配方法比速度匹配和"速度+姿态"匹配方法更适用于机翼存在较大弹性变形时的传递对准。另外,此种方法对由时间延迟所引起的时间标记偏差也有比较好的估计效果。     

基于QR分解的自适应差分滤波在SINS大方位失准角初始对准中的应用

针对差分滤波算法存在数值稳定性差及系统噪声统计特性不准确导致滤波性能下降 的问题,提出一种改进的差分滤波算法。新算法将矩阵QR分解及Cholesky分解因数更新技术 引入,并结合一种新的噪声估计方法及选择更新策略,有效地改善了系统噪声统计特性不准 确带来的滤波性能下降问题,增强了传统差分滤波算法的数值稳定性。通过在捷联惯导系统 大方位失准角初始对准中的应用,仿真结果表明了新算法的有效性和鲁 棒性 。
     

多通道投影图像的几何自动拼接技术

以低端摄像头产品为测量元件构造了实用的可扩展的多通道投影图像自动拼接系统;利用二次校准方法细化求解一致性矩阵,在投影屏幕上实现了多通道投影图像间的几何无缝拼接;特征图案的正确选择和二次校准方法最大限度地降低了摄像头性能对校准精度的影响;在满足相邻投影图像有重叠区域和摄像头能拍摄到重叠区域两个基本条件时,系统可实现自动拼接校准.实验表明,二次校准方法使校准时间明显缩短,使校准精度达到了亚像素级;低端摄像头、高效率的特征提取方法和一致性矩阵求解算法使系统扩展成本大大降低.      

An optimal beam alignment method for large-scale distributed space surveillance radar system

Large-scale distributed space surveillance radar is a very important ground-based equipment to maintain a complete catalogue for Low Earth Orbit (LEO) space debris. However, due to the thousands of kilometers distance between each sites of the distributed radar system, how to optimally implement the Transmitting/Receiving (T/R) beams alignment in a great space using the narrow beam, which proposed a special and considerable technical challenge in the space surveillance area. According to the common coordinate transformation model and the radar beam space model, we presented a two dimensional projection algorithm for T/R beam using the direction angles, which could visually describe and assess the beam alignment performance. Subsequently, the optimal mathematical models for the orientation angle of the antenna array, the site location and the T/R beam coverage are constructed, and also the beam alignment parameters are precisely solved. At last, we conducted the optimal beam alignment experiments base on the site parameters of Air Force Space Surveillance System (AFSSS). The simulation results demonstrate the correctness and effectiveness of our novel method, which can significantly stimulate the construction for the LEO space debris surveillance equipment.     

主子惯导坐标系失调动态估计补偿方法研究

本文研究了船体静态变形角、动态变形角引起的主子惯导坐标系失调角动态补偿方法。研究表明：速度加姿态匹配能够在线估计补偿船体静态变形引起的主子惯导坐标系失调角,角速度匹配传递对准方法能够在线估计补偿船体静态变形、动态变形引起的主子惯导坐标系失调角,两种匹配传递对准方法适用条件均受海况环境影响。     

惯性/里程计组合导航无地标行进中自主对准

载车行进中自主对准可有效缩短机动前准备时间,提高姿态对准精度以及对准过程中无地标自主定位精度是关键。本文提出一种里程计辅助捷联惯导系统行进中对准算法,推导了行进中精对准滤波模型以及对准过程中无地标自主定位算法。为缩短对准时间、减小由于航向角误差未收敛时造成的定位误差,利用回溯法将粗对准过程存储数据用于精对准过程,且回溯法仅需存储少量数据适合于工程应用。车载实测数据分析表明算法可同时实现行进中自主对准与对准过程中无地标自主定位,有效提高了载车快速机动能力,航向角对准精度优于1 mil,对准过程中无地标自主定位精度优于0.3%行程。     

Research on uncertainty in measurement assisted alignment in aircraft assembly

Operations in assembling and joining large size aircraft components are changed to novel digital and flexible ways by digital measurement assisted alignment.Positions and orientations（P＆O）of aligned components are critical characters which assure geometrical positions and relationships of those components.Therefore,evaluating the P＆O of a component is considered necessary and critical for ensuring accuracy in aircraft assembly.Uncertainty of position and orientation（U-P＆O）,as a part of the evaluating result of P＆O,needs to be given for ensuring the integrity and credibility of the result;furthermore,U-P＆O is necessary for error tracing and quality evaluating of measurement assisted aircraft assembly.However,current research mainly focuses on the process integration of measurement with assembly,and usually ignores the uncertainty of measured result and its influence on quality evaluation.This paper focuses on the expression,analysis,and application of U-P＆O in measurement assisted alignment.The geometrical and algebraical connotations of U-P＆O are presented.Then,an analytical algorithm for evaluating the multi-dimensional U-P＆O is given,and the effect factors and characteristics of U-P＆O are discussed.Finally,U-P＆O is used to evaluate alignment in aircraft assembly for quality evaluating and improving.Cases are introduced with the methodology.