便携式移动机器人INS/GPS组合导航系统研究

基于捷联惯导系统（INS）与全球定位系统（GPS）定位技术的发展以及机器人导航的需要，本文对INS与GPS的组合导航系统进行了研究。捷联惯导系统与GPS导航各有优缺点，具有互补性，文中将两者结合形成了更加准确可靠的定位系统。本文首先介绍了捷联惯导系统和全球定位系统，并对捷联惯导和GPS的误差作了详细的分析，建立了误差模型。文中应用动力学误差方程建立了九状态INS/GPS综合卡尔曼滤波方程。提出了一种以位置、速度、姿态DCM的误差为状态量，以GPS和INS的位置差作为观测量的INS/GPS组合导航系统的滤波算法，并将该技术应用于机器人的定位导航。仿真实验表明，该算法可有效提高系统导航参数的估计精度。本文分五章对该课题进行了研究。第一章是引言，介绍了课题的研究背景、意义，国内外的研究现状和本文的主要工作；第二章介绍了惯性传感器和GPS接收器的原理和特性；第三章介绍了捷联惯导系统相关的理论知识，包括姿态角的解算，算法具体内容和误差分析，并对捷联惯导系统进行了仿真试验；第四章介绍了Kalman滤波的相关知识并详细介绍了INS/GPS组合导航系统；第五章对INS/GPS组合导航系统的九状态卡尔曼滤波算法进行了仿真，并对试验结果进行了详细的分析。从仿真结果可知，组合导航系统大大的提高了系统的精度，克服了纯惯导系统的缺点。

GPS天线球在AUV上的拖曳运动分析

AUV在长时间作业过程中需要浮出水面进行GPS定位，既浪费时间又浪费能源，因此仿照潜艇上的拖曳天线的形式，在AUV上采用了形状简单的GPS天线球，这种天线球的拖曳运动特性是本文的主要研究内容。 本文分析了这种天线球在静水环境下的拖曳运动情况，建立了拖曳系统的数学模型。其中对于缆绳采用了Ablow提出的有限差分模型，对于自由表面上的天线球，采用水动力系数法进行分析，对耦合的系统采用前向差分法进行求解。在此基础上编制程序进行仿真。 为了验证仿真结果，在拖曳水池进行了拖曳试验。在试验中通过改变拖曳速度和缆绳长度，得到了一系列的张力数据和天线球姿态。对试验数据和计算结果的比较表明，上面的数学模型在速度小于2节时能够模拟真实情况，反之则会出现较大的误差。经过查找，本文排除了试验误差和计算参数选取不当这两个可能的原因，最终认定是天线球的模型不够完善，因为它在自由表面上受到了兴波阻力的作用。 本文也对有限差分程序的结果和叶果洛夫给出的缆绳数据进行了比较，比较表明基于本文编写的缆绳分析程序是可靠的。在此基础上，本文把拖曳试验测量到的张力作为边界条件对实际工程进行了分析计算，指出目前缆绳长度14米的情况不能满足期望的10米拖曳深度；若要拖曳深度达到10米，需要加大天线球的浮力并增加缆绳长度，本文也给出了这种情况下的几组参数的具体值。

GPS在自治水下机器人中的应用

本文首先介绍了GPS系统的构成及数据读取方法,着重介绍了GPS在“探索者”号和“CR-01”自治水下机器人中的应用,概述了这一领域的最新研究动态。

全球定位系统的车辆定位问题——GPS动态绝对定位模式的研究

随着GPS（全球卫星定位系统）技术的成熟与发展，利用GPS技术进行车辆定位正地被广泛地应用。例如金融系统（运钞车）、公安部门（110报警车）、消防部门（119消防车）、急救中心（120救护车）等。但是，利用GPS进行车辆定位跟踪的传统方法是采用差分GPS技术。该技术的实现需要大量的资金投入，不适于我国目前的经济状况。寻求一种投资少并能实现基本功能的算法从工程角度讲，具有十分现实的意义。本文以“沈阳市消防通讯作战指挥系统”为背景，以单台GPS接收机动态定位模式为实现条件，对车辆定位的实现进行了详细的讨论。首先，建成立了WGS-84坐标系到BJ-54坐标系之间的坐标转换模型，其次，提出了一种基于类投影的地图匹配算法，最后基于该算法进行了实际车辆定位实验。从实验结果看，该算法基本实现了车辆定位的功能。

基于GPS、GSM以及GIS技术的城市交通动态监控系统的设计及关键技术研究

随着城市交通日益繁忙，如何开发出一套定位精度高、价格低廉的车辆导航与定位系统，成为目前工TS（智能交通系统）中一个重要的研究部分。本文将GPS（全球定位系统）、GSM（全球移动通信系统）以及GIS（地理信息系统佩技术结合起来，开发出一套适合社会需求的车辆导航与定位系统，并对系统的设计、建立、系统功能、实现过程以及实验结果做了详尽的说明，提出了系统需要进一步改进的地方。系统总体工作的总体思路是使用安装在车辆上的GPS车载终端接收GPS卫星的定位信息、以GSM网络的短消息业务方式传回监控中心，在监控中心，GSM控制器将接收到的信息通过标准串口发送给监控计算机，监控计算机对信息、进行伪距一位置集中差分处理以及卡尔曼滤波，使定位精度由原来的100米左右提高到10米左右，然后使用集成地图的方法将其显示在地图上，以便作出合理的决策。

电离层行进式扰动的GPS台网监测研究

In this dissertation, we investigated two types of traveling ionospheric disturbances (TIDs)/gravity waves (GWs) triggered separately by auroral energy input during super geomagnetic storms and solar terminator (ST) under quiet geomagnetic conditions (kp<3+) using TEC measurements from the global network of GPS receivers. Research into the generation and propagation of TIDs/GWs during storms greatly enhance our understandings on the evolution processes of energy transportation from the high-latitude’s magnetosphere to the low-latitude ionosphere and the conjugated effect of TIDs propagation between the northern and southern hemispheres. Our results revealed that the conjugacy of propagation direction between the northern and southern hemispheres was subject to the influence of Coriolis force. We also figure out the evolution processes of ionospheric disturbances at the global scale. These are important topics that had not been well addressed previously. In addition, we also obtained thee wave structures of medium scale TIDs excited by the solar terminator (ST) moving over the northern America and physical mechanisms involved. Our observations confirm that the ST is a stable and repetitive source of ionospheric wave disturbances and the evidence of solar terminator generated disturbances has been demonstrated experimentally via the GPS TEC measurement. The main researches and results of this dissertation are as follows. First, the global traveling ionospheric disturbances (TIDs) during the drastic magnetic storms of October 29–31, 2003 were analyzed using the Global Position System (GPS) total electron content (TEC) data observed in the Asian-Australian, European and North American sectors. We collected the most comprehensive set of the TEC data from more than 900 GPS stations on the International GNSS Services (IGS) website and introduce here a strategy that combines polynomial fitting and multi-channel maximum entropy spectral analysis to obtain TID parameters. Moreover, in collaboration with my thesis advisor, I have developed an imaging technique of 2-dimensional map of TIDs structures to obtain spatial and temporal maps of large scale traveling ionospheric disturbances (LSTIDs). The clear structures of TEC perturbations map during the passage of TIDs were displayed. The results of our study are summarized as follows: (1) Large-scale TIDs (LSTIDs) and medium-scale TIDs (MSTIDs) were detected in all three sectors after the sudden commencement (SC) of the magnetic storm, and their features showed longitudinal and latitudinal dependences. The duration of TIDs was longer at higher latitudes than at middle latitudes, with a maximum of about 16 h. The TEC variation amplitude of LSTIDs was larger in the North American sector than in the two other sectors. At the lower latitudes, the ionospheric perturbations were more complicated, and their duration and amplitude were relatively longer and larger. (2) The periods and phase speeds of TIDs were different in these three sectors. In Europe, the TIDs propagated southward; in North America and Asia, the TIDs propagated southwestward; in the near-equator region, the disturbances propagated with the azimuth (the angle of the propagation direction of the LSTIDs measured clockwise from due north with 0°) of 210° showing the influence of Coriolis force; in the Southern Hemisphere, the LSTIDs propagated conjugatedly northwestward. Both the southwestward and northeastward propagating LSTIDs are found in the equatorial region. These results mean that the Coriolis effect cannot be ignored for the wave propagation of LSTIDs and that the propagation direction is correlated with the polar magnetic activity. (3) The day (day of year: 301) before the SC (sudden commencement) of magnetic storm, we observed a sudden TEC skip disturbances (±10 TECU). It should be a response for the high flux of proton during the solar flare event, but not the magnetic storms. Next, the most comprehensive and dense GPS network’s data from North-America region were used in this paper to analyze the medium scale traveling ionospheric disturbances (MSTIDs) which were generated by the moving solar terminator during the quiet days in 2005. We applied the multi-channel maximum entropy spectral analysis to calculated TID parameters, and found that the occurrence of ST-MSTIDs depends on the seasonal variations. The results of our study are summarized as follows: (1) MSTIDs stimulated by the moving ST (ST-MSTIDs) are detected at mid-latitudes after the passage of the solar terminator with the life time of 2～3 hours and the variation amplitude of 0.2～0.8 TECU. Spectral analysis indicated that the horizontal wavelength, average period, horizontal phase velocity of the MSTIDs are around 300±150 km，150±80 m/s and 25±15 min, respectively. In addition, ST-MSTIDs have wave fronts elongating the moving ST direction and almost parallel to ST. (2) The statistical results demonstrate that the dusk MSTIDs stimulated by ST is more obvious than the dawn MSTIDs in summer. On the contrary, the more-pronounced dawn MSTIDs occurs in winter. (3) Further analysis indicates that the seasonal variations of ST-MSTIDs occurrence frequency are most probably related to the seasonal differences of the variations of EUV flux in the ionosphere region and recombination process during sunrise and sunset period at mid-latitudes. Statistical study of occurrence characteristics of TIDs using the GPS network in North-American and European during solar maximum, In conclusion, statistical studies of the propagation characteristics of TIDs, which excited by the two common origins including geomagnetic storms and moving solar terminator, were involved with global GPS TEC databasein this thesis. We employed the multichannel maximum entropy spectral analysis method to diagnose the characteristics of propagation and evolvement of ionospheric disturbances, also, the characteristics of their regional distribution and climatological variations were revealed by the statistic analysis. The results of these studies can improve our knowledge about the energy transfer in the solar-terrestrial system and the coupling process between upper and lower atmosphere (thermosphere-ionosphere-mesosphere). On the other hand, our results of the investigation on TIDs generated by particular linear origin such as ST are important for developing ionospheric irregularity physics and modeling the transionosphere radio wave propagation. Besides, the GPS TEC representation of the ST-generated ionospheric structure suggests a better possibility for investigating this phenomenon. Subsequently, there are scientific meaning of the result of this dissertation to deeply discuss the energy transfer and coupling in the ionosphere, as well as realistic value to space weather forecast in the ionosphere region.

Associations between BMI and home, school and route environmental exposures estimated using GPS and GIS: do we see evidence of selective daily mobility bias in children?

BACKGROUND: This study examined whether objective measures of food, physical activity and built environment exposures, in home and non-home settings, contribute to children's body weight. Further, comparing GPS and GIS measures of environmental exposures along routes to and from school, we tested for evidence of selective daily mobility bias when using GPS data. METHODS: This study is a cross-sectional analysis, using objective assessments of body weight in relation to multiple environmental exposures. Data presented are from a sample of 94 school-aged children, aged 5-11 years. Children's heights and weights were measured by trained researchers, and used to calculate BMI z-scores. Participants wore a GPS device for one full week. Environmental exposures were estimated within home and school neighbourhoods, and along GIS (modelled) and GPS (actual) routes from home to school. We directly compared associations between BMI and GIS-modelled versus GPS-derived environmental exposures. The study was conducted in Mebane and Mount Airy, North Carolina, USA, in 2011. RESULTS: In adjusted regression models, greater school walkability was associated with significantly lower mean BMI. Greater home walkability was associated with increased BMI, as was greater school access to green space. Adjusted associations between BMI and route exposure characteristics were null. The use of GPS-actual route exposures did not appear to confound associations between environmental exposures and BMI in this sample. CONCLUSIONS: This study found few associations between environmental exposures in home, school and commuting domains and body weight in children. However, walkability of the school neighbourhood may be important. Of the other significant associations observed, some were in unexpected directions. Importantly, we found no evidence of selective daily mobility bias in this sample, although our study design is in need of replication in a free-living adult sample.

Changes in the attitudes of GPs to health screening of patients with learning disabilities

GP's appear reluctant to undertake health screening for people with learning disabilities. This article describes a specialist health screening service delivered mainly by community learning disability nurses to nearly 600 children and adults. Prior to the service being established, 141 GPs within a defined area were surveyed and 51% responded. Although a majority thought the service would be helpful, three-quarters felt it was better provided within the context of specialist services. After screening, 54% of the sample (318 persons) were referred to their GP for further assessment and treatment, nearly all for physoical health needs. A second study investigated the attitudes of 91 GPs who had patients refrrered. Those (45) who reported dealing with a referral were more favourably disposed to undertaking health screening within their practice, whereas those (23) who had been uninvolved continued to opt for specialist provision. Options for encouraging more GPs' to offer preventive health care to theisclient group are discussed, including medical training, extra consulting time and linking community learning disbaility nurses with GP practices.