复杂低空飞行中机会信号导航的信号优选及融合定位方法研究

Precise navigation posioning ensures the flight safety. However, it is possible that satellites are hidden for the avation emergency rescue in the complex low airspace. The navigation technology is restricted to play its role. Therefore, in this project the fusion navigation method with signals of opportunity and GPS is proposed to improve the navigation availability and accuracy for incompleteless navigation information in the complex low airspace. Aiming at the key problem of airplanes high dynamic variation, the irregular distribution in the complex low airspace, the multi-source and neterogeny of signals of opportunity, this project will analyse the properties of signals of opportunity and build the signal quality model with the seperation for dynamics and statics to promote the availability of signals of opportunity assisted navigation for high dynamic users. Based on the signal quality model, the stratified optimization choice method for signals of opportunity will be presented in the irregular distribution to solve signals discontinuous problems, increasing the positioning accuracy. Then, the conevolution fusion positioning algorithm for multi-source and neterogeny signals and GPS will be raised to improve the algorithm computation efficiency. Lastly, at the aviation emergency rescue scene, the simulation platform will be set up for the fusion navigation positioning with signals of opportunity and GPS. This project is to break through the key technology of the fusion navigation with multi-source and neterogeny signals and GPS, providing theoretical and methodological basis for the aviation emergency rescue navigation in the complex low airspace.

精准导航定位引导是飞行器安全飞行的保障。然而，在复杂低空应急救援飞行环境中，卫星导航信号易被地形遮挡，导航技术难以发挥导航定位的作用。因此，本项目提出采用机会信号与GPS 融合导航方法，从而提升导航信息不完备情形下复杂低空飞行的导航可用性及精确性。针对复杂低空环境飞行器高动态变化、机会信号分布不规则、机会信号多源异质等关键问题，本项目深入分析机会信号特性，建立机会信号动静态分离式质量模型，提升机会信号对高动态用户辅助导航的可用性；以信号质量模型为基础，研究机会信号分布不规则的信号层次优选方法，解决机会信号不连续的信号选择问题，提高导航定位的精确性；提出多源异质机会信号与GPS的协同进化融合定位算法，提高算法运行的效率；并以航空应急救援为场景，搭建复杂低空飞行的机会信号与GPS融合导航平台。本项目旨在突破多源异质机会信号与GPS融合定位的关键技术，为复杂低空飞行的导航定位提供理论和方法支撑。

本项目依照计划执行完成。面向复杂低空飞行精准引导需求，研究机会信号与 GPS融合导航方法。突破复杂低空环境飞行器高动态变化的信号质量建模、机会信号分布不规则的信号层次优选、多源异质机会信号与GPS的融合定位等关键技术，为复杂低空应急救援飞行的导航提供理论和方法支持。.在飞行器高动态变化的信号质量建模方面，提出了分离的信号质量建模方法，依据质量模型预测导航的可用性，分析了机会信号的特点、属性及定位体制，将机会信号定位方法与GPS测距体制一致表示；然后，建立了机会信号的质量模型，有效地描述机会信号相对飞行器的变化特征；最后，基于信号质量模型分析机会信号的几何结构特征。.在机会信号分布不规则的信号层次优选方法方面，提出了层次优选机会信号，从选择类型至选择信号组，再选择信号源。首先，分析了机会信号各类型的特点，选取了可用于复杂低空飞行的类型；对各类信号归一化处理，聚类分组机会信号，选取各信号的质量差作为相似度测量参数，相似性传播聚类获得相似信号类组；最后，层次优选信号，依据类组的中心点，以GDOP最小为目标，确定所选类组，从所选的类组中，继续以GDOP最小为目标，选择确定类组内的机会信号。该算法可以大大提高复杂低空飞行中信号选择的效率。.在多源异质机会信号与GPS的融合定位算法研究方面，提出了协同进化加权的融合定位方法均衡各信号间的性能，权重的变化受机会信号性能、位置区域等约束，根据权重的调整衡量信号源在融合定位中的重要程度。各类组信号均以构建较优的几何结构为目标与其它类组信号组合，协同过程通过类组合作的方式计算几何精度因子，从而实现依据适应度变化动态调整各信号在类组中的权重。