单频低成本GNSS接收机单历元姿态解算新方法

A new approach to single-epoch attitude determination for single-frequency low-cost GNSS receivers

GNSS姿态解算由于其廉价、高效的优点,越来越多地被应用于各导航定位领域。消费市场下的导航定位定姿模块多采用低成本接收机,面临较大的多路径影响、频繁的周跳,甚至矢锁等诸多问题。模糊度固定作为GNSS姿态解算的关键,在城市复杂环境中将受到更多挑战。本文根据C-Lambda算法,通过单基线固定时另外一个姿态角的自由度搜索,分别将其纳入姿态域和模糊度域,进行模糊度函数的全局最小化搜索计算基线向量,提出C-Lambda-Search及C-Lambda-A Search方法;采用3个低成本接收机(ublox-M8T)和贴片天线,在不同环境中分别进行不同基线长度的静态及动态车载试验。两个试验均证明,在模糊度固定效果及欧拉角计算精度上,本文方法有很大提升,且计算负担在可接受范围内,是一种实用性强的车载定姿算法。

GNSS attitude determination is increasingly applied in various navigation and positioning fields due to its cost-effectiveness.Navigation and positioning modules in the consumer market often employ low-cost receivers,which face challenges such as significant multipath effects,frequent cycle slips and integer ambiguities,among others.In complex urban environments,ambiguity fixing,a crucial component of GNSS attitude determination,encounters even more challenges.In this paper,based on the C-Lambda algorithm,we propose the C-Lambda-Search and C-Lambda-A Search methods.These methods involve a search for the degrees of freedom of another attitude angle when fixing ambiguities with a single baseline.They are employed to perform global minimization of the ambiguity function in both the attitude and ambiguity domains,aiming to calculate baseline vectors.We conduct static and dynamic vehicle experiments with three low-cost receivers(ublox-M8T)and patch antennas in different environments with varying baseline lengths.Both experiments demonstrate that the methods proposed in this paper significantly improve ambiguity fixing performance and Euler angle calculation accuracy.Furthermore,the computational burden remains within an acceptable range.These methods prove to be practical and effective for vehicle attitude determination.