Time-SEP Comprehensive Assessment of Methods for Calculating Positioning Accuracy of Navigation Systems

2013 ◽  
Vol 765-767 ◽  
pp. 2026-2030 ◽  
Author(s):  
Rui Jiang ◽  
Yan Yong Wang ◽  
Gong Liu Yang ◽  
Yong Miao Wang

Based on 2 statistical testing schemes, the accuracy evaluation method of Time-SEP was proposed; 3 sphere error probability (SEP) methods were derivate and concluded. Simulation and experimental verification show that: Time-SEP method for navigation equipment positioning accuracy can give a relatively comprehensive evaluation; the scheme is feasible, compatible with the traditional calculation method of parameters and can fully utilize the single test data, test validation simple. 3 algorithms can all be used to calculate SEP, the maximum relative error is less than 5%; the χ2 distribution approximation somewhat conservative is recommended; and MLE values can be used as the initial value of integral operation, to reduce the number of integral operation, access to the true value rapidly.

2013 ◽  
Vol 765-767 ◽  
pp. 2224-2228 ◽  
Author(s):  
Yan Yong Wang ◽  
Gong Liu Yang ◽  
Xing Rong Jia ◽  
Yong Miao Wang

in order to satisfy the positioning accuracy identification requirement of MUAV navigation system, the characteristics of visual navigation were analyzed, the existing navigation system accuracy assessment methods were summarized and the conversion relationship of each index were deduced. According to the Ethridge statistical algorithm for calculating circular error probability (CEP), navigation and positioning accuracy assessment scheme were designed. Finally, the time-CEP(TCEP) accuracy evaluation method based on visual measurement was put forward, which were verified by simulation using four group actual INS data .The results show that: the scheme is feasible, convenient and practical; the method can relatively comprehensive evaluate the positioning accuracy of navigation system and can make full use of the single trial data.


2014 ◽  
Vol 541-542 ◽  
pp. 869-874
Author(s):  
Hui Ping Zheng ◽  
Min Xue ◽  
Yan Zhao ◽  
Xin Yuan Liu ◽  
Yu Han

In order to overcome the shortcomings of the present accuracy assessment methods of power system dynamic simulation, this paper focuses the permanent single phase short-circuit fault which occurs in a large probability in power grids,and selects the typical electrical quantities which is very concerned in engineering after the fault happened. A time-scale based error criteria on simulation validation is proposed, and a comprehensive error criteria according to the average errors between simulation data and actual data is proposed to evaluate objectively the simulation accuracy of the typical electrical quantities. Considering the variation characteristics of the electrical quantities, the simulation accuracy evaluation of a single electrical element is expended to the simulation accuracy evaluation of the entire network, so not only the comprehensive evaluation about the model and its parameters but also the information for model modification and parameter correction can be obtained. The effectiveness of the proposed method is verified by the numerical results on the New England 10 Unit 39 Bus powers system.


2014 ◽  
Vol 1014 ◽  
pp. 443-446
Author(s):  
Qiu Shui Yao ◽  
Guo Ping Li

Bottom dead center (BDC) is an important performance index of press,but how to precisely evaluate the accuracy of BDC is a technical problem faced by the press industry. Based on fuzzy judgment method and analytic hierarchy process (AHP), this paper constructs a comprehensive evaluation index to analyze and evaluate the position of the BDC accuracy.Evaluation step is a system operated by selecting evaluation factors and building evaluation set to determine the comparison matrix, to calculate the weight of each factor, and to establish fuzzy evaluation matrix, and through comprehensive evaluation model to judge the BDC accuracy level. It shows that this evaluation method can effectively evaluate the accuracy of press.


2020 ◽  
Vol 64 (1-4) ◽  
pp. 1365-1372
Author(s):  
Xiaohui Mao ◽  
Liping Fei ◽  
Xianping Shang ◽  
Jie Chen ◽  
Zhihao Zhao

The measurement performance of road vehicle automatic weighing instrument installed on highways is directly related to the safety of roads and bridges. The fuzzy number indicates that the uncertain quantization problem has obvious advantages. By analyzing the factors affecting the metrological performance of the road vehicle automatic weighing instrument, combined with the fuzzy mathematics theory, the weight evaluation model of the dynamic performance evaluation of the road vehicle automatic weighing instrument is proposed. The factors of measurement performance are summarized and calculated, and the comprehensive evaluation standard of the metering performance of the weighing equipment is obtained, so as to realize the quantifiable analysis and evaluation of the metering performance of the dynamic road vehicle automatic weighing instrument in use, and provide data reference for adopting a more scientific measurement supervision method.


Author(s):  
V.V. Kostenko ◽  
Yu.V. Vaulin ◽  
F.S. Dubrovin ◽  
O.Yu. Lvov

Буксируемый подводный модуль (БПМ) эффективно используется для решения задач, связанных с координированием подводных объектов, местоположение которых подлежит уточнению в процессе их детальногообследования. При этом большое значение имеет точность определения координат самого буксируемогомодуля относительно судна-буксировщика. Использование гидроакустических навигационных средств, вчастности систем с ультракороткой базой (ГАНС УКБ), ограничено вследствие помех, влияющих на качествосигналов в приемной антенне. Альтернативой служит метод определения координат БПМ на основе данныхтраекторных измерений параметров буксируемой системы. К числу последних относятся расчетные значенияпараметров кабеля связи в установившихся режимах буксировки, значения путевой скорости и путевого углабуксировщика, а также измеренные значения длины кабеля, глубины погружения и курса БПМ. В работе дансравнительный анализ различных вариантов вычислительных алгоритмов, позволяющих получить оценки точности определения координат БПМ в различных режимах стационарной буксировки и при наличии сбоев вработе навигационных средств.The towed underwater module (TUM) is a useful toolfor solving problems of the positioning of the underwaterobjects, the location of which must be clarified during its detailedinspection. Herewith, the accuracy of the determinationof the coordinates of the towed module itself relative tothe towing vessel is essential for such kind of problems. Theuse of underwater acoustic navigation means, the systemswith ultra-short baseline (USBL) in particular, are limiteddue to interference affecting the quality of the signals on thereceiving antenna. As an alternative, the method is proposedfor TUM positioning based on trajectory measurements ofparameters of the towed system, which may include calculatedvalues of communication cable parameters in steadystatetowing modes, values of ground speed and towing angle,as well as measured cable length, immersion depth, andTUM heading. The paper provides a comparative analysisof various versions of computational algorithms, which allowobtaining estimates of the TUM positioning accuracy indifferent modes of stationary towing and in the presence offailures in navigation systems operation.


2019 ◽  
Vol 98 ◽  
pp. 01034 ◽  
Author(s):  
Mingjun Liu ◽  
Changlai Xiao ◽  
Xiujuan Liang

In this study, a hydrochemical investigation was conducted in Shuangliao city to identify the hydrochemical characteristics and the quality of groundwater using descriptive statistics and correlation matrices. And on that basis, combined with Analytic hierarchy process (AHP), an improved two-level fuzzy comprehensive evaluation method is used to evaluate the groundwater quality. The results indicate that the major cations and anions in groundwater are Ca2+ and HCO3-, respectively. The chemical types are mainly HCO3—Ca type water, some areas are complicated due to the influence of human activities. The evaluation results show that the water quality in the area is mostly III type water, and the groundwater quality in some areas is IV or V water due to the influence of primary geological conditions or human activities. The groundwater quality in the East Liaohe River Valley and Shuangliao urban area is relatively poor, and in the northwest part which is the saline alkali soil area is also relatively poor.


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