Replacing the observed object in a dynamic measuring system

In this article the problem of an object state vector estimation is considered. This estimation is obtained by the treatment of measured parameters from several observed objects. In our case, we have two measured parameters that change their values over a certain time interval, but only one of them can be measured at each moment. The problem is to find the moment for switching the measurement from one object to another one in order to minimize the dispersion of one component of the state estimation vector. Previously, the Elfing problem was solved to repeatedly measure fixed parameters using this data in proportion to weight coefficients for processing with the least square method. Then, to change the measured values, a transfer from the discrete model to the continuous one was proposed. This made it possible to obtain an analytical expression dispersion that was dependent of the time moment on the switching. In this article, the estimation of the continuous model error is conducted and the sufficient conditions of using no more than one switching are proven. An example of this method’s application is shown to estimate the sea object coordinates using navigation satellites.

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Study on determination method of hydrodynamic coefficient of Marine pile foundation

E3S Web of Conferences ◽

10.1051/e3sconf/202014301021 ◽

2020 ◽

Vol 143 ◽

pp. 01021

Author(s):

Jiang Zongnan

Keyword(s):

Fourier Analysis ◽

Time History ◽

Least Square Method ◽

Wave Force ◽

Least Square ◽

Irregular Waves ◽

Hydrodynamic Coefficient ◽

Irregular Wave ◽

Advantages And Disadvantages ◽

The Moment

The irregular waves are simulated by using standard spectrum. Instantaneous value method, Fourier analysis method, least square method and "harbour hydrological code" are used to determine the moment force of coefficient CM and drag coefficient CD. Then CM and CD that linearized by Borgman L.E. equation are substituted into Morison equation. The time history curve of the wave force on the pile is calculated and compared with the measured wave force data under the action of irregular wave to analyze the advantages and disadvantages of several methods to determine CM and CD. The results show that the comparison between CM and CD determined by Fourier analysis and least square method is practical.

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Subpixel Edge Detection Algorithm of the Glass Bottle Based on Zernike Moments

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.80-81.1345 ◽

2011 ◽

Vol 80-81 ◽

pp. 1345-1349

Author(s):

Hao Yang ◽

Lei Pei

Keyword(s):

Edge Detection ◽

Fast Algorithm ◽

Least Square Method ◽

Threshold Value ◽

Detection Algorithm ◽

Zernike Moments ◽

Least Square ◽

Measuring System ◽

Zernike Moment ◽

Glass Bottle

The accuracy of edge detection determines the accuracy of actual dimension measurement，in order to improve the measuring accuracy, this paper proposes a fast algorithm of detecting the glass bottle dimension based on Zernike moments. Firstly, combines the traditional Zernike moment-based method with Otsu adaptive threshold algorithm and a new fast algorithm for edge detection is proposed. Then uses this fast algorithm to detect the edge of glass bottle with subpixel-level and uses the least square method to fit ellipses formed by the glass bottle mouth and bottom. Calibrated the system with standard gauge block and obtain the actual dimension at last. Experimental results show that the improved algorithm not only can make the edge detection reach the subpixel-level accuracy, but also can avoid the edge misidentification and inefficient causing by repeatedly manual adjustments to select the threshold value when detecting the edge. Making a rapid, accurate, non-contact measuring system becomes a reality.

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Research on the Size Measurement of Shaft Parts Based on Image Processing

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.466-467.602 ◽

2012 ◽

Vol 466-467 ◽

pp. 602-606

Author(s):

Xiao Yan Shang ◽

Ji An Wu ◽

Xing Wang ◽

Liu Nan

Keyword(s):

Solution Method ◽

Ccd Camera ◽

Least Square Method ◽

Least Square ◽

Calibration Coefficient ◽

Size Measurement ◽

Pixel Size ◽

Sobel Operator ◽

Dynamic Measuring ◽

Image Edge

non-contact measurement of shaft component realizes dynamic measuring ,which bases on image measurement technology.After the image of shaft is obtained,Sobel operator is used for preliminary locating to image edge,on basis of this ,discrete points of image edge are fitted by least square method for achieving edge subpixel location.By precision analysis, size solution method is acquired when the error is minimum;After calibration coefficient k is gained, the part size is correctly calculated. By experiment, it shows that measurement precision is improved effectively and measurement error is less than ±20μm when resolution of CCD camera is 1392×1040 and its pixel size is 4.65μm.

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An Algorithm and Design for RFID Velocity Measurement Based on Least Square Method

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.317-319.1573 ◽

2011 ◽

Vol 317-319 ◽

pp. 1573-1576

Author(s):

Lin Ying Jiang ◽

Heng Zhang ◽

Han Qing Tan

Keyword(s):

Great Degree ◽

Velocity Measurement ◽

Least Square Method ◽

Least Square ◽

Measuring System ◽

Rfid Technology ◽

Velocity Measuring ◽

The Cost

This paper comes up with an algorithm and application for velocity measurement based on RFID technology. This measurement can reduce the cost of velocity-measuring system to a great degree, and improve the accuracy of velocity measurement on the basis of the algorithm.

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A Study on Velocity Decay of φ6mm Tungsten Ball Fragment

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1042.154 ◽

2014 ◽

Vol 1042 ◽

pp. 154-158

Author(s):

Chun Lin Yi ◽

De Ren Kong ◽

Yi Zhao Li ◽

Li Ping Li ◽

Jin Qiu Zhang ◽

...

Keyword(s):

High Speed ◽

Least Square Method ◽

Least Square ◽

Experimental Results ◽

Measuring System ◽

Low Speed ◽

Velocity Decay ◽

Velocity Attenuation ◽

Attenuation Models ◽

Velocity Measuring

In order to explore the velocity attenuation law and model of φ6mm tungsten ball fragment, theory analysis combined with tests is employed to study its velocity experimental results. First of all, a fragment velocity measuring system including 12 groups of cutting device is established. Then the attenuation experiments of φ6mm tungsten ball fragment in high speed and low speed velocity are performed by the measuring system. Based on the least-square method, MATLAB software is adopted to analysis the experimental data and obtained the high speed and low speed velocity attenuation models. The results show that φ6mm tungsten ball fragment speed attenuation coefficient is consistent in high speed and low. Thus, the analysis on velocity experimental results verifies that the established model is reasonable.

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Development of Measurement System for Accuracy Control in Subsection Manufacture

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.381-382.79 ◽

2008 ◽

Vol 381-382 ◽

pp. 79-82

Author(s):

F. Zhang ◽

Xing Hua Qu ◽

J.F. Dai ◽

S. Ye

Keyword(s):

Least Square Method ◽

Least Square ◽

Measuring System ◽

Large Radius ◽

Accuracy Control ◽

Data Processing Software ◽

Geometrical Information ◽

Cloud Points ◽

Processing Software ◽

Best Fit

The computer aided measuring system is established to evaluate geometrical information of the structure in subsection manufacture. The cloud points data of surface are collected by laser tracker so as to explore continuing data processing software and evaluate the error of dimension and shape, and then the real measuring model, matched by the corner information, is compared with CAD through the best-fit algorithm. The lack of fitting information which will cause the low measuring precision is solved by the least square method constrained by radius in structure with large radius and small central angle. As the research object, the tunnel structure is used in the quality control of manufacturers.

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Design of Geometric Error Measuring System on a Miniaturized Machine Tool with Optics

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.364-366.1215 ◽

2007 ◽

Vol 364-366 ◽

pp. 1215-1220 ◽

Cited By ~ 2

Author(s):

Wei Wang ◽

Sung Hwan Kweon ◽

Young Suk Kim ◽

Seung Han Yang

Keyword(s):

Machine Tool ◽

Least Square Method ◽

Geometric Error ◽

Least Square ◽

Measuring System ◽

Geometric Errors ◽

Motion Direction ◽

Position Sensing ◽

System Components ◽

Configuration Simulation

Manufactured miniature parts conventional machine tools are substituted by mini-scale manufacturing system called miniaturized machine tool (mMT). However, calibration of mMT is extremely difficult due to its small dimensions. This paper presents a novel optical measuring system to measure integrated geometric errors namely a) three translation errors and b) three rotational errors. The squareness error between two moving axes was calculated by least-square method. These 7-DOF geometric errors were acquired simultaneously in one setup for each motion direction. The proposed measuring system consisted of two laser diodes, two beam splitters and three 2D position sensing detectors (PSDs). Configuration of this measuring system was proved by homogenous transformation matrix (HTM), and the relationship between PSD readings and geometric errors calculated by the algorithm were derived according to the configuration. Simulation were carried out to prove the validity of this algorithm. Sensitivity analysis based on mounting errors of system components is also presented in this paper. It is useful for further experiments in alignment of system components.

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Accurate Estimation of Phase Distribution on Reference Plane in Grating Projection Measurement

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.295-296.221 ◽

2005 ◽

Vol 295-296 ◽

pp. 221-226 ◽

Cited By ~ 1

Author(s):

M.R. Zhao ◽

Yu Cheng Lin ◽

X.B. Niu ◽

D.M. Cheng

Keyword(s):

Phase Distribution ◽

Phase Error ◽

Random Phase ◽

Taylor Series Expansion ◽

Least Square Method ◽

Least Square ◽

Measuring System ◽

Reference Plane ◽

Accurate Estimation ◽

Rational Polynomial

A binary second order rational polynomial is adopted to simulate and extend the phase distribution on reference plane. In order to get the coefficients of the polynomial accurately, iterative least-square method based on the first order Taylor series expansion is used. The effect of the real reference plane profile error on measuring result is reduced by using extended unwrapped phase to substitute the original unwrapped phase. The effects of the random phase error and the system geometrical parameter error are decreased. The measuring accuracy of the system is improved. The principle of the 3D profile measuring system based on grating projection, the theoretic analysis for accurate estimate of phase distribution on reference plane, and the experimental results are presented.

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The Speeds and Accelerations of the Galaxies Movements According to Redshift Measurements

Proccedings of 10th International Conference "Environmental Engineering" ◽

10.3846/enviro.2017.241 ◽

2017 ◽

Author(s):

Jonas Skeivalas ◽

Eimuntas Parseliunas

Keyword(s):

Doppler Effect ◽

Least Square Method ◽

Systematic Errors ◽

Least Square ◽

Signal Frequency ◽

Time Interval ◽

The Galaxy ◽

Speed Change ◽

The Doppler Effect ◽

The Universe

The theoretical presumptions and some experimental calculations to analyse the speeds of the galaxies movements according to redshift measurements applying the Doppler effect are presented. The speed of the galaxy movement is treated as multidimensional continuous value, when values of the speed vector are calculated according to measurements of the redshift parameter z at corresponding moments of the universe lookback time. The most reliable values of the galaxy speeds vector are calculated applying the least square method to the vector of z measurements and including the additional parameters to eliminate the possible systematic errors. The acceleration of the galaxy movement is calculated as a speed fluxion according to period of the adopted redshift signal frequency and as a speed change during the lookback time interval. The expressions of functions of the galaxies speeds and accelerations are received by the polynomial approximation, when values of the polynomial parameters are calculated by the least square method.

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