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1.
When using the signal from the Global Positioning System (GPS) for precise estimation of a vehicle’s heading, the main challenge is finding the integer ambiguities in the carrier phase measurements. If the distance between the receiver’s antennas, also known as baseline length, is used in the process of solving that challenge, the resulting solution’s stability and precision can be enhanced, particularly for single-frequency L1 receivers. This paper presents a study of the overall influence of this baseline length in the precision and accuracy of the heading estimation, using raw measurements from two GPS single-frequency L1 receivers. Conclusions are presented based on the results from field trials for baselines up to 8 m.  相似文献   

2.
刘鑫  王媛媛 《现代导航》2022,13(6):426-432
针对在林荫道、高架桥和隧道等城市峡谷中全球定位系统(GPS)信号易发生遮挡、 干扰,导致导航定位精度低、连续性和可靠性差的问题,提出了一种基于几何精度因子(GDOP) 和非完整性约束(NHC)的 GPS/惯性测量单元(IMU)组合导航方法。其中,通过利用 GDOP 实现卫星定位构型优劣和定位精度的衡量,从而构建基于 GDOP 值的 GPS/IMU 组合导航量测更新模型。同时,为了进一步提高组合导航系统的精度,将 NHC 应用于该组合导航系统中。实验结果表明,所提方法水平和三维定位均方根误差分别是 3.88 m 和 4.78 m,相比于传统 GPS/IMU 组合导航方法的 9.25 m 和 13.53 m 分别提高了 58.06%和 64.67%,可以有效抑制 GPS 信号受环境干扰影响组合导航定位精度和可靠性的问题。  相似文献   

3.
Global positioning system (GPS) has undergone intensive development, starting as an advanced specialized tool to a general-purpose gadget used in our daily lives. GPS exists in new technologies, applications, and consumer products, especially in smartphones and tablets. In a GPS receiver design, power consumption and localization accuracy are critical factors that affect the outcome of a GPS receiver system. Theoretically, increasing the number of required tracking channels in a GPS baseband receiver increases the design complexity and size of this system. Thus, power consumption can significantly increase. The receiver should acquire and track numerous satellites to improve the location accuracy of a position, thereby indicating that the receiver requires a high number of tracking channels. Thus, optimizing these tracking channels to balance the conflict among performance parameters is a difficult and challenging task. This paper presents a technique for order performance by similarity to ideal solution (TOPSIS) for solving complex situations for multi-criteria optimization of the tracking channels of GPS baseband telecommunication receiver. Nine operation modes of GPS receiver were evaluated by each design parameter, such as power consumption, localization accuracy, and time with no position available for static and dynamic positioning. Then, the TOPSIS was utilized and implemented to measure and rank the overall performance of tracking channel selection. Results of this study indicate that (1) multi-objective optimization is a reliable strategy for visualizing the trade-off among the GPS design parameters and providing a dynamic power consumption planning. (2) The best aggregated performance of the GPS receiver occurs when the number of tracking channels equals five and six for static and dynamic positioning, respectively. (3) The most frequent number of available satellites is eight, whereas the other number of satellites is a rare case to acquire. However, GPS standards require that available GPS satellites are constantly 12 at any time and place.  相似文献   

4.
基于软件的GPS信号捕获跟踪算法研究   总被引:1,自引:0,他引:1  
对GPS软件接收机的捕获和跟踪部分进行了研究。对于捕获模块,通过对常用串行搜索捕获算法和并行频域搜索捕获算法的比较和分析,提出了一种新型并行码相位搜索捕获算法;对于跟踪模块,提出采用非相干延迟锁相环对码进行跟踪,同时采用Costas环对载波进行跟踪;最后,从捕获和跟踪的GPS信号中提取出导航电文,并根据电文中的参数计算出了用户的位置坐标,并在Matlab中对用户的位置坐标进行了定位解算验证。  相似文献   

5.
为了寻找一种新的评定飞行试验中真航向精度的方法,文中采用全球定位系统(GPS)作为参考基准,以两套不同型号的惯导系统作为试验对象,通过飞行试验研究惯导系统航迹误差与真航向误差的相关性。试验数据及分析结果表明,采用航迹误差间接评定真航向精度是可信的。  相似文献   

6.
Coordinated positioning operations require the user to be aware, not only, of his own position but also of the positions of the other elements on his team. Its deployment can be supported in WAW (??Where Are We???) location-based services, where the position of each user is made available to the rest of the group. This paper presents a method for the estimation of a user??s position based on measurements from a group of Global Positioning System (GPS) receivers. None of the GPS receiver positions, used in the estimation process, is considered to be known. The proposed approach leads to an improvement on the accuracy of the position estimates, when compared with those computed on an autonomous way, and has a direct application in the development of enhanced services in WAW location-based services. The positioning estimator takes advantage from the fact that, in this type of location-based service, GPS measurements are available from several receivers. Instead of estimating the user??s position based only on the measurements of his own GPS receiver, the proposed approach uses the measurements from all the GPS receivers in the group. The paper presents details of the positioning model and estimator used to achieve the accuracy improvements. Simulation results are presented based on real GPS satellite ephemeris, collected at the University campus.  相似文献   

7.
马朋 《现代导航》2019,10(4):247-252
针对交替领航下的多自主水下航行器(AUV)协同定位系统,利用级联滤波架构设计了一种多 AUV 协同定位自适应滤波算法,通过将协同定位系统中的跟随 AUV 状态估计分解为航向估计与位置估计两部分,克服了在仅有部分距离量测下航向角估计可观测性差的影响,减小了距离量测误差模型不确定所引起的定位误差波动。同时,引入算法复杂度评价标准对所设计的级联自适应滤波算法进行分析。仿真结果表明,该算法具有较高的定位精度,可有效降低计算复杂度。  相似文献   

8.
In certain cases, due to such high precision of geographical position estimation, there problems connected with the accuracy of systems for the projection of the globe convex surface to the two-dimensional surface of a chart emerge. When using DGPS, one should pay closer attention if the chart datum is compliant with GPS. Although DGPS can increase the precision of the SPS several times, the accuracy improvement of the PPS is very limited. Satellite navigation systems used for non-military purposes found their application mainly in maritime and aerial navigation; however, recently they started to invade inland applications. Expensive cars are being equipped with such systems, which transmit signals from remotely controlled transmitters hidden in vehicles in case of theft. Today, one can buy an inexpensive GPS or DGPS receiver capable of displaying position and travelled distance on a map of any selected region, in selected scale and with a variety of useful information such as location of hotels, restaurants, museums, or gas stations. Many developed countries are beginning to implement GPS receivers equipped with an interactive vehicle communication system that connects them with traffic control centres.  相似文献   

9.
针对低精度微惯性测量单元/全球导航卫星系统 (IMU/GNSS)松组合导航系统中初始方位难以精确得到和行进间航向容易发散的问题,该文设计了一种双天线辅助的两段连续式对准方法。首先分析了初始方位误差对航向精度的影响;其次,由于GNSS测向系统精度高、无姿态漂移误差的特点,基于双天线基线矢量推导了一种最小二乘算法的测姿模型,进行初始对准;最后针对行进间对准,研究扩展了基于航向差值的1维量测以抑制航向发散。设计试验探讨了双天线基线矢量对初始对准与行进间航向精度的影响,改进方法可以使得初始方位误差优于0.7°,行进间航向能够更准确地被跟踪。针对目标的初始对准与行进间对准,双天线可提供辅助信息,其效果优于单天线IMU/GNSS的组合,且方法计算量适中。  相似文献   

10.
为了隔离载体扰动对天线指向的影响,研究了单基线GPS和微惯性传感器组合的低成本姿态估计及稳定方法。该方法以四元素和陀螺误差作为状态变量,根据陀螺角速率信息、加速度计的重力场信息和单基线GPS航向信息分别建立状态方程和量测方程,设计具有不同测量周期的平方根差分滤波分别融合惯性传感器和GPS信息,解决了加速度计与单基线GPS航向信息输出频率不一致问题;利用估计出的姿态角在角位置环路上对天线进行捷联稳定,隔离载体扰动。仿真结果表明,平方根差分滤波能有效估计出载体姿态,利用中等精度的微惯性器件可以满足动中通姿态稳定的需求。  相似文献   

11.
Acquiring precise navigation data is a vital process to unmanned vehicles. Although Inertial Navigation System and Global Positioning System (INS/GPS) integrated system provides accurate and continuous navigation solution, the navigation solution accuracy degrades during GPS outages. In order to provide accurate and continuous navigation data during GPS outages, a novel architecture of a cascaded neural networks is proposed to estimate velocity and position errors during GPS signal blockage to handle the time dependency and non-linearity modeling. An ablation study is conducted to grasp the proposed model hyper parameters and their impacts on overall accuracy. Various scenarios are carried out by building and using different grades IMU models. These models are examined through two distinct trajectories for flying and ground platforms to assure the proposed algorithm applicability scope and efficiency. Furthermore, a comparative analysis is carried out based on a real-field test to evaluate the proposed algorithm efficiency and navigation accuracy during GPS outages. The proposed system proves its superiority against the legacy Extended Kalman Filter (EKF) and the advanced Recurrent Neural Network (RNN) based systems in terms of navigation performance during GPS outages periods.  相似文献   

12.
GPS系统多普勒频移估算的研究   总被引:4,自引:0,他引:4  
在GPS导航定位系统中,多普勒频率偏移直接影响接收机性能。为了克服多普勒频率偏移的影响,提高接收机的GPS信号捕获速度,对多普勒频移估计算法进行了研究。推导了导航卫星运行参数的数学模型,给出多普勒频移估算的数学模型,对导航卫星运行参数及多普勒频移特性进行了MATLAB仿真。结果表明,卫星与接收机之间的相对位置对信号的多普勒频移特性有着较强的影响。仿真结果可以为多普勒频移的估计和补偿提供先验信息。  相似文献   

13.
高动态环境存在较大的多普勒频移,这使得普通的GPS接收机在没有惯导辅助的情况下很难可靠工作。为了同时满足高动态GPS接收机动态性能和跟踪误差两方面的需要,本文提供了一种以DSP为核心的高动态GPS接收机设计方案,并对其各模块的功能进行了详细的解释说明。为了帮助DSP的设计,本文还研究了3种适应高动态环境的GPS信号参数估计算法,包括最大似然估计算法,卡尔曼滤波算法和频率扩展卡尔曼滤波算法。通过仿真,比较分析了这3种算法的估计精度和动态跟踪能力等性能。并对高动态GPS中的DSP实用化的设计方案进行了探讨分析。  相似文献   

14.
In this paper, a map‐matching (MM) algorithm which combines an estimated position with digital road data is proposed. The presented algorithm using a virtual track is appropriate for a MEMS‐based pedestrian dead reckoning (PDR) system, which can be used in mobile devices. Most of the previous MM algorithms are for car navigation systems and GPS‐based navigation system, so existing MM algorithms are not appropriate for the pure DR‐based pedestrian navigation system. The biggest problem of previous MM algorithms is that they cannot determine the correct road segment (link) due to the DR characteristics. In DR‐based navigation system, the current position is propagated from the previous estimated position. This means that the MM result can be placed on a wrong link when MM algorithm fails to decide the correct link at once. It is a critical problem. Previous algorithms never overcome this problem because they did not consider pure DR characteristics. The MM algorithm using the virtual track is proposed to overcome this problem with improved accuracy. Performance of the proposed MM algorithm was verified by experiments.  相似文献   

15.
在室内行人导航中,为获取精确的航向角,提出了一种基于二阶插值滤波的航向估计算法。该算法通过建立四元数姿态运动测量模型,采用二阶插值滤波对陀螺仪、加速计和磁强计的测量数据进行数据融合,实现航向角解算,以过程噪声和测量噪声为设计参数,构造自适应噪声协方差矩阵,实现协方差误差估计最小化。通过对行走长方形参考路径得到的数据进行处理,加速计和磁强计组合与陀螺仪航向估计算法动态误差分别为13.6°和6.9°,采用二阶插值滤波航向估计算法后动态误差为2.3°。实验结果表明,该算法有效提高了航向估计的精度,减小了陀螺仪漂移、载体的线性加速度和周围局部磁场干扰对航向估计的影响。  相似文献   

16.
针对INS/GPS组合导航系统在GPS信号被遮挡时,GPS接收机失锁导致导航精度迅速下降的问题,提出了基于BP神经网络辅助的组合导航算法。即在GPS信号锁定的时候,采用卡尔曼滤波对INS/GPS信号进行数据融合得到实时的精确位置,同时利用组合导航输出信息对BP神经网络进行实时在线训练;一旦GPS失锁,利用之前训练好的神经网络对INS系统进行误差补偿,解决精度迅速下降问题。通过跑车实验证明,速度精度在0.2m/s以内,位置精度为25m以内,该算法对INS/GPS组合导航系统有效。  相似文献   

17.
刘程  周本清  宋军  刘勇 《压电与声光》2014,36(3):389-392
以无人机组合导航系统为研究背景,针对磁传感器的误差校准方法,以及校准后磁航向误差进行研究。通过分析磁传感器误差来源,给出水平面内椭圆直接拟合模型。考虑磁传感器修正后的磁航向与GPS航迹角之间存在一定误差,建立航向误差角与磁航向之间的学习函数,从而辅助在GPS丢失情况下,采用学习后的磁航向来辅助无人机导航。飞行实验结果表明,利用该文采用的椭圆模型以及自学习函数,能够提高磁航向精度,从而可以辅助无人机在GPS丢失情况下航向解算。  相似文献   

18.
在GPS现代化过程中,GPS L5新信号采用了QPSK调试方式,它由数据支路和导频支路组成.为了开发GPS L5新信号接收机,在研究信号特征的基础上,给出了接收机的总体设计思路并讨论了相应的捕获技术、跟踪技术以及导航电文的译码技术.接收机信号处理基于FPGA实现,连接卫星导航模拟器,该接收机成功捕获、跟踪和解调了GPS L5信号,并得到了正确的定位结果.对接收机的输出结果进行了测试,证明了设计L5接收机过程中所采用方法的有效性和可行性.  相似文献   

19.
基准站钟差是卫星定位系统定位误差的重要来源。为了准确校正基准站钟差以提高定位精度,提出一种基于三参数时钟模型、Singer运动目标模型和Kalman模型的基准站钟差估计算法。实验采用NOVATEL高精度接收机接收卫星的GPS实时数据以提高实验的可靠性。基于Matlab平台对钟差参数、定位坐标和定位误差进行仿真计算,结果证明其能有效提高GPS定位精度。  相似文献   

20.
刘明阳 《现代导航》2022,13(2):114-117
GPS 利用卫星发射的无线电信号,通过计算卫星与 GPS 接收机之间的相对位置, 进而确定出用户接收机在地球上的位置,可以为用户接收机提供实时的定位、测速和授时等服务。 通过使用最小二乘法,对 GPS 的定位解算算法进行研究,设计了一种基于最小二乘法的 GPS 定位解算算法。通过使用模拟源对所设计的 GPS 定位算法进行了定位解算试验验证,将定位解算结果与设定的模拟接收机位置进行比较,试验结果表明,该定位解算算法具有良好的定位效果。  相似文献   

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