惯导辅助GNSS整周模糊度快速固定算法与实现

发布时间：2018-07-07 07:35

本文选题：GNSS + 惯性导航系统　；参考：《合肥工业大学》2017年硕士论文

【摘要】：对于GNSS动态相对定位,当卫星信号被遮挡、干扰时,会导致失锁。在信号重新捕获时,如何快速、准确的确定整周模糊度是研究的热点和难点问题,也是实现高精度GNSS动态相对定位的关键。根据惯性导航系统(Inertial Navigation System,INS)短时间内精度较高,不易受到外界干扰的特点,如果采用INS输出的高精度定位结果作为先验信息,辅助GNSS固定整周模糊度,可以缩小模糊度搜索空间,较少固定整周模糊度所需要的时间。本文提出了使用INS输出的位置信息辅助确定整周模糊度算法:在分析INS独立导航精度的基础上,利用INS辅助确定模糊度,比较恢复整周模糊度所需要的时间,评估加入INS对固定整周模糊度的帮助。本文的研究内容主要包含以下几个方面:1.介绍了INS解算中常用的坐标系,给出了地心地固坐标系下INS解算载体位置的原理及过程,并使用模拟数据对算法进行验证,结果表明INS具有短时间内精度较高的特点,但误差会随时间积累,并呈指数型增长。2.介绍了GNSS载波相对定位和整周模糊度解算算法,其中重点介绍了最小二乘降相关平差法(Least-square AMBiguity Decorrelation Adjustment,LAMBDA)算法。然后使用模拟数据验证了算法正确可靠。3.使用实测数据分别计算了GNSS独立解算和INS辅助下的整周模糊度固定时间,并进行定量对比,结果表明,如果出现短时间的信号失锁,在INS的辅助下,固定模糊度所需要的时间可以被大幅度缩短;当信号失锁持续两秒内时,整周模糊度可以被瞬时恢复。
[Abstract]:For GNSS dynamic relative positioning, when the satellite signal is blocked and interfered, it will lead to the loss of lock. How to determine the integer ambiguity quickly and accurately is a hot and difficult problem in signal re-acquisition, and it is also the key to realize dynamic relative positioning of high-precision GNSS. According to the characteristics that the inertial Navigation system (ins) has high accuracy in a short period of time and is not easily disturbed by the outside world, if the high precision positioning result of ins output is used as a priori information to assist GNSS to fix the integer ambiguity, the ambiguity searching space can be reduced. Less time required to fix full-cycle ambiguity. In this paper, an algorithm for determining integer ambiguity using position information from ins output is presented. On the basis of analyzing the accuracy of ins independent navigation, the ambiguity degree is determined by using ins aid, and the time required to recover the ambiguity is compared. Evaluate the contribution of ins to fixed integer ambiguity. The research content of this paper mainly includes the following several aspects: 1. This paper introduces the coordinate system commonly used in the ins solution, gives the principle and process of the position of the ins solution carrier in the geocentric solid coordinate system, and verifies the algorithm by using the simulated data. The results show that ins has the characteristics of high precision in a short time. But errors accumulate over time and increase exponentially. In this paper, GNSS carrier relative location and integer ambiguity resolution algorithm are introduced, and the Least-square AMBiguity correlation adjustment algorithm is emphasized. Then the simulation data is used to verify the correctness and reliability of the algorithm. 3. The fixed time of integer ambiguity under the aid of ins and GNSS independent solution are calculated using the measured data, and the quantitative comparison is made. The results show that, if a short period of time signal is lost, under the aid of ins, The time required for fixed ambiguity can be greatly shortened, and the whole cycle ambiguity can be instantly restored when the signal loses its lock for two seconds.
【学位授予单位】：合肥工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P228.4

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