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SINS/GPS组合导航系统仿真研究 总被引:2,自引:0,他引:2
以某载体的规划航迹数据为对象,针对捷联、卫星组合导航系统(SINS/GPS)进行了仿真研究。由规划航迹数据计算出载体的比力和角速度信息,输入至惯性测量器件模型,模型输出激励捷联解算模块,得到惯导系统输出参数;同时对规划数据添加观测噪声模拟GPS测量值。采用相对简单的基于半位置、半速度误差的误差方程作为状态方程,以松耦合方式进行集中式Kalman滤波,给出了SINS单独工作与SINS/GPS组合得到的半位置、半速度误差分布。对各状态的观测度进行了研究,确定了不可观测的状态并给出了部分状态可观测度的时间分布。仿真结果表明,方法正确有效,可对SINS/GPS组合导航系统进行算法验证和方案性评估。 相似文献
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GPS是应用最为广泛的室外定位系统,随着技术的发展精度不断提升.然而城市中,由于GPS卫星信号被建筑遮挡,仍然可能产生较大的多径误差.此类误差已称为城市GPS定位误差的主要成分.评估城市道路中环境对GPS精度的负面影响,即环境的GPS友好度,将有助于对不同地段GPS的误差范围进行预判,从而提升位置服务相关应用的用户体验,并为理解环境特征与多径误差的关系,确定在何处部署辅助定位的设备提供支持.为此,提出了1种通过处理和分析海量公交车GPS轨迹历史数据,从而评估城市主要路段的环境友好性的方法.该方法充分利用公交车运行线路固定的特点,大幅提升数据处理的效率;针对路网数据可能存在的错误,提出了容错性的方案;利用相同车辆及相同路段在GPS误差上存在的内在关联,对缺失数据进行补全;并充分考虑到不同质量GPS端设备对环境友好性评估的影响,确定了基于端设备质量加权的评估计算策略.利用成都市二环内的4869辆公交车1个月的数据,对共计5648个不同路段的环境友好性进行了评估,并通过卫星地图和街景照片,分析验证了方法结果的合理性. 相似文献
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As location data are widely available to portable devices, trajectory tracking of moving objects has become an essential technology for most location-based services. To maintain such streaming data of location updates from mobile clients, conventional approaches such as time-based regular location updating and distance-based location updating have been used. However, these methods suffer from the large amount of data, redundant location updates, and large trajectory estimation errors due to the varying speed of moving objects. In this paper, we propose a simple but effcient online trajectory data reduction method for portable devices. To solve the problems of redundancy and large estimation errors, the proposed algorithm computes trajectory errors and finds a recent location update that should be sent to the server to satisfy the user requirements. We evaluate the proposed algorithm with real GPS trajectory data consisting of 17201 trajectories. The intensive simulation results prove that the proposed algorithm always meets the given user requirements and exhibits a data reduction ratio of greater than 87% when the acceptable trajectory error is greater than or equal to 10 meters. 相似文献
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针对无线传感器网络协作通信过程中误差传播对系统性能的影响,提出了一种基于机会式误差修正的可靠传输机制。首先,在多节点协作无线传感器网络中建立三种协作传输方案,基于信道质量和误符号率建立协作误差传播模型。接着,针对协作误差中的合并、调度和干扰等类型,通过在信道、信源和协作网络物理层提出机会式误差修正算法。最后,在上述结论基础上,综合感知用户的性能要求、调度复杂度和协作传播模型,提出了机会式可靠传输机制。数学分析结果不仅验证了机会式传输机制比静态机制具有高可靠性,而且证明了所提机制在端到端通信的实时性、可靠性、吞吐率和能效等方面有优越性。 相似文献
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提高GPS定位精度的数据处理技术 总被引:12,自引:0,他引:12
尽管全球定位系统(GPS)已经是目前精度最高的无线电导航系统,但仍有许多用户不满足于GPS定位的原始精度,希望获得更高的性能。基于GPS输出信息的数据处理就是一种广泛采用的技术。GPS数据基本的处理方法有两种:基于GPS接收机输出数据的滤波、平滑处理;基于两个或多个GPS接收机的差分校正处理(DGPS)。差分GPS只能消除选择可用性和电离层时延等公共误差,对多径干扰仍无能为力。多径已成为近距差分的主要误差源。为了抗多径,本文还综述了两种先进的GPS数据处理方法:空间-时间处理抗多径方法和数据诊断与剔除抗多径方法。 相似文献
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As the use of smartphones spreads rapidly, user localization becomes an important issue for providing diverse location-based services (LBS). While tracking users in outdoor environments is easily done with GPS, the solution for indoor tracking is not trivial. One common technique for indoor user tracking is to employ inertial sensors, but such a system needs to be capable of handling noisy sensors that would normally lead to cumulative locating errors. To reduce such error, additional infrastructure has often been deployed to adjust for these cumulative location errors. As well, previous work has used highly accurate sensors or sensors that are strapped to the body. This paper presents a stand-alone pedestrian tracking system, using only a magnetometer and an accelerometer in a smartphone in indoor corridor environments that are normally laid out in a perpendicular design. Our system provides reasonably accurate pedestrian locations without additional infrastructure or sensors. The experiment results show that the location error is less than approximately 7 m, which is considered adequate for indoor LBS applications. 相似文献
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Improved Modeling of Elevation Error with Geostatistics 总被引:2,自引:0,他引:2
Peter Fisher 《GeoInformatica》1998,2(3):215-233
The elevations recorded within digital models are known to be fraught with errors of sampling, measurement and interpolation. Reporting of these errors according to spatial data standards makes several implicit and unacceptable assumptions about the error: it has no spatial distribution, and it is statistically stationary across a region, or even a nation. The approach explored in this paper employs actual elevations measured in ground and aerial survey at higher precision than the elevations in the DEM and recorded on standard paper maps. These high precision elevations are digitized and used to establish the real statistical and spatial distribution of the error. Direct measurements could also have been taken in the field by GPS or any other means of high precision data collection. These high precision elevations are subtracted from values stored in the DEM for approximately the same locations. The distribution of errors specific to the DEM can then be explored, and can be used in the geostatistical method of conditional stochastic simulation to derive alternative realizations of the error modeled and so of the DEM. Multiple versions of the derived products can also be determined. This paper compares the results of using different methods of error modeling. The best method, which gives widely implementable and defensible results, is that based on conditional stochastic simulation. 相似文献
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Susanne M. M. de Mooij Maartje E. J. Raijmakers Iroise Dumontheil Natasha Z. Kirkham Han L. J. van der Maas 《Journal of Computer Assisted Learning》2021,37(1):242-252
While response time and accuracy indicate overall performance, their value in uncovering cognitive processes, underlying learning, is limited. A promising online measure, designed to track decision-making, is computer mouse tracking, where mouse attraction towards different locations may reflect the consideration of alternative response options. Using a speedy arithmetic multiple-choice game in an online adaptive learning environment, we examined whether mouse movements could reflect arithmetic difficulties when error rates are low. Results showed that mouse movements towards alternative responses in correctly answered questions mapped onto the frequency of errors made in this online learning system. This mapping was stronger for the younger children, as well as for easy arithmetic problems. On an individual level, users showed more mouse movement towards their previously made response errors than towards other alternative options. This opens the possibility of adapting feedback and instruction on an individual basis through mouse tracking. 相似文献
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This work presents an automated system for the measurement of form errors of mechanical components using an industrial robot. A three-probe error separation technique was employed to allow decoupling between the measured form error and errors introduced by the robotic system. A mathematical model of the measuring system was developed to provide inspection results by means of the solution of a system of linear equations. A new self-calibration procedure, which employs redundant data from several runs, minimizes the influence of probes zero-adjustment on the final result. Experimental tests applied to the measurement of straightness errors of mechanical components were accomplished and demonstrated the effectiveness of the employed methodology. 相似文献
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Young Min Yoo Joon Goo Park Dal Ho Lee Chan Gook Park 《International Journal of Control, Automation and Systems》2012,10(2):298-307
A theoretical method for analyzing the observability of a strapdown inertial navigation system (SDINS) integrated with the
global positioning system (GPS) is proposed. The analysis is performed based on two types of maneuvers for a vehicle on a
horizontal trajectory: level flight with constant north velocity and level flight with constant east velocity. The observability
also is analyzed using the convergence theorem, stationary state observability analysis results, and Kalman filter measurement
information to rearrange the SDINS error model equation. The state variables are divided into observable and unobservable
parts, and determine which state variables are observable and estimable with some errors from the relationship of observable
and unobservable state variables. Our results have shown that the north and east axes accelerometer bias errors were unobservable,
and that attitude errors, and east and down axes gyro bias errors were estimable with some unknown bias errors. It has been
shown that horizontal maneuvering improves the observability of down axis gyro bias error compared with the stationary state,
and the estimation errors of the heading error state and east axis gyro bias error are dependent on the magnitude of north
velocity. The results of the theoretical observability analysis are confirmed through computer simulation. 相似文献
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This paper describes human errors and violations of end users and network administration in computer and information security. This information is summarized in a conceptual framework for examining the human and organizational factors contributing to computer and information security. This framework includes human error taxonomies to describe the work conditions that contribute adversely to computer and information security, i.e. to security vulnerabilities and breaches. The issue of human error and violation in computer and information security was explored through a series of 16 interviews with network administrators and security specialists. The interviews were audio taped, transcribed, and analyzed by coding specific themes in a node structure. The result is an expanded framework that classifies types of human error and identifies specific human and organizational factors that contribute to computer and information security. Network administrators tended to view errors created by end users as more intentional than unintentional, while errors created by network administrators as more unintentional than intentional. Organizational factors, such as communication, security culture, policy, and organizational structure, were the most frequently cited factors associated with computer and information security. 相似文献
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针对基于偏移量计算的轨迹数据压缩算法中对于关键点的评估不足以及基于在线轨迹数据压缩算法中累积误差和对偏移量考虑不足的问题,提出一种基于运动状态改变的在线全球定位系统(GPS)轨迹数据压缩算法——限定同步欧氏距离(SED)的阈值结合算法(SLTA)。该算法通过轨迹点的转向角度大小和速度变化大小来评估轨迹点信息量的大小;同时用SED限制点的偏移量,以达到较好的信息保留度。实验结果表明,SLTA的轨迹压缩率能够达到50%左右,与阈值结合算法(TA)相比,SLTA的平均SED误差(5 m以内)可以忽略不计;相对于基于偏移量计算的轨迹数据压缩算法,SLTA的平均角度误差最小(1.5°~2.3°),运行时间最稳定。SLTA能够稳定有效地进行在线GPS轨迹数据压缩。 相似文献
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为了提高GPS里程统计的精度,提出了一种基于栅格三元距离变换的GPS里程统计算法.首先,将离散的GPS轨迹数据映射成为连续的栅格序列,进而通过三元栅格子序列的空间排列定义距离变换算子,并基于统计分析建立距离变换算子的动态调整模型,进行误差补偿,最终实现高精度的GPS里程统计.为验证算法有效性,设置了连续线段法与栅格欧氏距离变换法两个传统里程统计算法作为对照组,进行里程统计对比实验.实验中,该算法里程统计误差均值约0.24%,标准差为0.55%.相较于对照组算法,该算法表现出了更好的误差特性,实现了更高的里程统计精度. 相似文献
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共同杂波环境下多目标量测数据的误差传递与校正 总被引:2,自引:0,他引:2
在目标跟踪领域, 如何提高目标航迹估计精度是一个重要问题. 传统做法是基于目标量测数据进行滤波或者融合以减小随机误差. 本文提出了基于误差相关性提高估计精度的新思路. 在强相关条件下, 依据误差基本理论, 研究了多目标之间量测数据误差传递和校正的概念、原理和方法, 建立并给出了各关键步骤的算法. 仿真实验表明, 多目标量测数据误差之间具有相关性时, 可以进行误差的传递和校正. 如果相关性较强, 则校正后量测数据精度能够得到较大幅度的提高. 相似文献