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1.
This is the second of two consecutive papers (Part II) in this journal on the monitoring of the integrity of integrated GPS/INS
systems. Part I established that the worst class of error for an integrated system in terms of failure detection performance
is that of slowly growing errors (SGEs). It was also concluded that among the integration architectures, the tightly coupled
architecture provides the best mechanism to tackle SGEs due to its simpler structure and accessibility to the relevant measurements.
In a subsequent comparison of the existing integrity algorithms, the multiple solution separation (MSS) and autonomous integrity
monitoring by extrapolation (AIME) methods were selected for further analysis because of their representative characteristics
of the current integrity algorithms. This paper carries out a detailed investigation of the capability of the MSS and AIME
algorithms to deal with the SGEs, using a realistic simulation platform and limited real data analysis. Results show that
although it is possible for the existing algorithms to detect SGEs, the time it takes to detect them varies inversely to the
rate of growth of the SGE. A new algorithm is developed to deal with this based on the concept of rate detection. Simulation
results show that the new algorithm can detect SGEs earlier than the current algorithms. This is validated by preliminary
tests with real data. 相似文献
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This paper (the first part of two to be published in this journal) presents the process and results of a critical review of
the integrated GPS and inertial navigation system (INS) architectures, the corresponding failure modes and the existing integrity
monitoring methods. The paper concludes that tightly coupled GPS/INS systems have the highest potential for detecting slowly
growing errors (SGEs). This is due to access to pseudorange measurements and a relatively simpler configuration compared to
the other architectures. The second paper (Part II) takes this further and carries out a detailed characterisation of the
performance of the current integrity algorithms for tightly coupled systems and develops a new algorithm that detects SGEs
faster than the current methods. 相似文献
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The problem of navigation systems with uncertain noise is considered. A minimax robust filtering which can minimize the worst
performance under noise uncertainties using the game theory is proposed. This new filter is applied to an integrated GPS/INS
navigation system. A high dynamics aircraft trajectory is designed to test the new filter. The results show that minimax robust
filtering performs better than standard Kalman filtering when noise parameters of an inertial measurement unit change their
statistical properties.
Received: 21 October 1997 / Accepted: 26 May 1999 相似文献
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GPS/MEMS INS integrated system for navigation in urban areas 总被引:1,自引:2,他引:1
This paper evaluates the performance of a tightly coupled GPS/INS integrated system based on low cost MEMS IMUs in dense urban
areas, and investigates two different methods to improve its performance. The first method used is to derive observations
from two different constraint equations reflecting the behavior of a typical land vehicle. The first constraint equation is
derived assuming that the vehicle does not slip and always remains in contact with the ground. If these assumptions are true
the velocity of the vehicle in the plane perpendicular to the forward direction should be zero. The second constraint equation
is derived from the fact that the height does not change much in a short time interval in a land vehicular environment. Thus,
when a GPS outage occurs (partial/complete), the integrated system combines the INS and constraints-derived virtual measurements
to keep the position and velocity errors bounded. This method is suitable for use in real-time applications. The second method
is specifically suitable for a post-mission application and involves the use of Rauch-Tung-Striebel (RTS) smoother. The designed
system performance is evaluated using two data sets collected in dense urban areas. The obtained results demonstrate the effectiveness
of different algorithms considered, in controlling the INS error growth, and indicates the potential of MEMS IMUs for use
in land vehicle navigation applications. 相似文献
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Dong-Hwan Hwang Sang Heon Oh Sang Jeong Lee Chansik Park Chris Rizos 《GPS Solutions》2005,9(4):294-311
Due to their complementary features of GPS and INS, the GPS/INS integrated navigation system is increasingly being used for
a variety of commercial and military applications. An attitude determination GPS (ADGPS) receiver, with multiple antennas,
can be more effectively integrated with a low-cost IMU since the receiver gives not only position and velocity data but also
attitude data. This paper proposes a low-cost attitude determination GPS/INS integrated navigation system. The proposed navigation
system comprises an ADGPS receiver, a navigation computer unit (NCU), and a low-cost commercial MEMS IMU. The navigation software
includes a fault detection and isolation (FDI) algorithm for integrity. In order to evaluate the performance of the proposed
navigation system, two flight tests have been performed using a small aircraft. The first flight test confirmed the fundamental
operation of the proposed navigation system and the effectiveness of the FDI algorithm. The second flight test evaluated the
performance of the proposed navigation system and demonstrated the benefit of GPS attitude information in a high dynamic environment.
The flight test results show that the proposed ADGPS/INS integrated navigation unit gives reliable navigation performance
even when anomalous GPS data is provided and gives better navigation performance than a conventional GPS/INS unit. 相似文献
7.
A combined algorithm of improving INS error modeling and sensor measurements for accurate INS/GPS navigation 总被引:1,自引:1,他引:1
Although the integrated system of a differential global positioning system (DGPS) and an inertial navigation system (INS)
had been widely used in many geodetic navigation applications, it has sometimes a major limitation. This limitation is associated
with the frequent occurrence of DGPS outages caused by GPS signal blockages in certain situations (urban areas, high trees,
tunnels, etc.). In the standard mechanization of INS/DGPS navigation, the DGPS is used for positioning while the INS is used
for attitude determination. In case of GPS signal blockages, positioning is provided using the INS instead of the GPS until
satellite signals are obtained again with sufficient accuracy. Since the INS has a very short-time accuracy, the accuracy
of the provided INS navigation parameters during these periods decreases with time. However, the obtained accuracy in these
cases is totally dependent on the INS error model and on the quality of the INS sensor data. Therefore, enhanced navigation
parameters could be obtained during DGPS outages if better inertial error models are implemented and better quality inertial
measurements are used. In this paper, it will be shown that better INS error models are obtained using autoregressive processes
for modeling inertial sensor errors instead of Gauss–Markov processes that are implemented in most of the current inertial
systems and, on the other hand, that the quality of inertial data is improved using wavelet multi-resolution techniques. The
above two methods are discussed and then a combined algorithm of both techniques is applied. The performance of each method
as well as of the combined algorithm is analyzed using land-vehicle INS/DGPS data with induced DGPS outage periods. In addition
to the considerable navigation accuracy improvement obtained from each single method, the results showed that the combined
algorithm is better than both methods by more than 30%. 相似文献
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GPS/INS组合制导技术在现代战争中的应用及发展趋势 总被引:2,自引:2,他引:0
现代战争大量使用精确制导武器,广泛应用先进的GPS/INS组合制导技术。分析了GPS/INS组合制导技术的优势,结合其在军事领域的应用,展望了GPS/INS关键技术的发展趋势。 相似文献
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A wavelet-extreme learning machine for low-cost INS/GPS navigation system in high-speed applications
The combined navigation system consisting of both global positioning system (GPS) and inertial navigation system (INS) results in reliable, accurate, and continuous navigation capability when compared to either a GPS or an INS stand-alone system. To improve the overall performance of low-cost micro-electro-mechanical systems (MEMS)-based INS/GPS by considering a high level of stochastic noise on low-cost MEMS-based inertial sensors, a highly complex problems with noisy real data, a high-speed vehicle, and GPS signal outage during our experiments, we suggest two approaches at different steps: (1) improving the signal-to-noise ratio of the inertial sensor measurements and attenuating high-frequency noise using the discrete wavelet transform technique before data fusion while preserving important information like the vehicle motion information and (2) enhancing the positioning accuracy and speed by an extreme learning machine (ELM) which has the characteristics of quick learning speed and impressive generalization performance. We present a single-hidden layer feedforward neural network which is employed to optimize the estimation accuracy and speed by minimizing the error, especially in the high-speed vehicle and real-time implementation applications. To validate the performance of our proposed method, the results are compared with an adaptive neuro-fuzzy inference system (ANFIS) and an extended Kalman filter (EKF) method. The achieved accuracies are discussed. The results suggest a promising and superior prospect for ELM in the field of positioning for low-cost MEMS-based inertial sensors in the absence of GPS signal, as it outperforms ANFIS and EKF by approximately 50 and 70%, respectively. 相似文献
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在GPS/INS辅助航空摄影测量作业过程中,如果GPS失锁时间过长将会影响到整个机载POS数据后处理精度,从而影响制图效果。文章旨在研究解决传统基于位置、速度组合的松耦合导航系统在GPS失锁情况下后处理精度不高的问题,提出基于伪距、伪距率的紧耦合导航系统:在保证外符合精度前提下,后处理后的位置内符合精度达到0.05m、航向角内符合精度约为0.005deg,各项指标均满足国外GPS/INS辅助航空摄影测量系统解算精度要求。研究结果可以为解决相关问题提供参考。 相似文献
16.
Due to the different signal frequencies for the GLONASS satellites, the commonly-used double-differencing procedure for carrier phase data processing can not be implemented in its straightforward form, as in the case of GPS. In this paper a novel data processing strategy, involving a three-step procedure, for integrated GPS/GLONASS positioning is proposed. The first is pseudo-range-based positioning, that uses double-differenced (DD) GPS pseudo-range and single-differenced (SD) GLONASS pseudo-range measurements to derive the initial position and receiver clock bias. The second is forming DD measurements (expressed in cycles) in order to estimate the ambiguities, by using the receiver clock bias estimated in the above step. The third is to form DD measurements (expressed in metric units) with the unknown SD integer ambiguity for the GLONASS reference satellite as the only parameter (which is constant before a cycle slip occurs for this satellite). A real-time stochastic model estimated by residual series over previous epochs is proposed for integrated GPS/GLONASS carrier phase and pseudo-range data processing. Other associated issues, such as cycle slip detection, validation criteria and adaptive procedure(s) for ambiguity resolution, is also discussed. The performance of this data processing strategy will be demonstrated through case study examples of rapid static positioning and kinematic positioning. From four experiments carried out to date, the results indicate that rapid static positioning requires 1 minute of single frequency GPS/GLONASS data for 100% positioning success rate. The single epoch positioning solution for kinematic positioning can achieve 94.6% success rate over short baselines (<6 km). 相似文献
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DAI LiwenHAN ShaoweiChris Rizos 《地球空间信息科学学报》2001,4(4):9-18
1 IntroductionReal_timekinematicGPSprecisepositioninghasbeenplayinganincreasingroleinbothsurveyingandnavigation ,andhasbecomeanessentialtoolforpreciserelativepositioning .However,reliableandcorrectambiguityresolutiondependsonobserva tionsuponalargenumbe… 相似文献
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正全球卫星导航系统可在无遮蔽环境中为用户提供高精度、低频率的导航定位服务,但在复杂环境中,GNSS信号易被遮挡或干扰。惯性导航系统经过初始化后,能够独立自主提供高频率、连续的位置、速度和姿态信息。通过二者合理结合,能够在遮蔽或半遮蔽环境中为用户提供连续且可靠的导航解。本文重点研究了GNSS/INS组合导航系统初始化及其故障修复方法,内容包括高精度惯导快速自对准技术、大失准角故障处理、磁力计辅助MEMS IMU抗差自适应姿态融合、神经网络辅助GNSS/INS组合导航系统故障识别与修复和惯导辅助BDS三频周跳探测与修复技术等,主要研究成果如下: 相似文献
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惯性导航与卫星导航紧耦合技术发展现状 总被引:1,自引:0,他引:1
对紧耦合方案、最优估计滤波算法和硬件开发等几方面进行了总结分析。分析了传统的INS/GPS松组合系统和INS/GPS紧耦合系统的区别;给出了INS/GPS紧耦合系统国内外的发展状况;指出INS/GPS紧耦合系统所涉及的关键技术。 相似文献