Coordinates Of Measurement Points Research Articles

Shell Deformation During the Construction of Record Span Soil-steel Buried Structure in Ras-Al-Khaimah (UAE)

Abstract The algorithm presented in this paper concerns the processing of data in the form of coordinates of measurement points located around the structure periphery, obtained from the geodetic measurements. The geometric parameter used here to study the deformation of the steel shell is the change of curvature. It is used to estimate the bending moment and hence the normal stress in the corrugated steel shell. The results given in the examples of calculations of the analyzed structure show the possibility of determining places with extreme values. For this purpose, a dense layout of measuring points and use the precision geodesy technique is necessary. Of significant importance in stress estimation is the correction of the geodetic measurement base. This is due to the fact that the points in the initial measurement do not lie on a section of the circle as a reference curve, used to determine the deformation of the shell.

THE BOTTOM RELIEF OF VYZYRKA POND (ODESSA REGION, ODESSA DISTRICT)

Problem Statement and Purpose. For arid conditions of southern Ukraine, the problem of preservation and use of the local water resources has been relevant for a long time. One of the types of adaptation of economic activity to the natural conditions of the area is artificial water bodies’ creation. Operation of ponds without repair work led to reduction of the water surface area of most of them, siltation, reduction of depths, overgrowth, as a result of which the ponds from water accumulators turned into evaporators. The publications review devoted to ponds and artificial reservoirs showed that their hydrochemical, hydrobiological regime, hydrological elements and ecological condition are mainly studying. The purpose of the research is to establish the regularities of the relief structure of the bottom of the pond in the village of Vyzyrka. Data & Methods. Field research was conducted in July 2021–2022. From two reservoirs, located within the village of Vyzyrka, the larger one was investigated. Work in the water area was carried out from the rowing boat Kolibri. The depths were determined with a Garmin Echo 200 echo sounder a geodetic rail. The use of the echo sounder made it possible to visually trace the relief of the bottom changes on the tacks and choose typical underwater points during relief measurements (ND31– 7.002.-2005). The depths were determined at 60 points, located evenly across the water area. The coordinates of measurement points were determined using a Garmin GPS72H GPS receiver. The journal of points was exported to Garmin Base Camp software. Results. Vyzyrska Pond has existed as an artificial reservoir since 1923. The relief has a trough-like shape inherited from the beam relief. Three areas are distinguished in the structure of the bottom relief: flat bottom of the northern part; underwater continuation of concave coastal slopes; the central depression stretches along the axis of the reservoir from southeast to northwest. The creation and use of artificial reservoirs leads to the development of geomorphological processes associated with the interaction of the native relief, which was formed in other physical and geographical conditions, with the water environment. Further studies of the pond are aimed at establishing the spatial distribution of hydrological elements in the water area of the pond in order to establish patterns of their change, which are important for the aquatic biota development.

Magnetotelluric Sounding in the Arctic Using a Drifting Station on an Ice Floe (Numerical Experiment)

Abstract —The magnetotelluric sounding (MTS) method implemented on drifting ice floes in the Arctic is suitable for detection of 3D inhomogeneities in crustal conductivity while recording the transverse magnetic (TM) mode potential of the electromagnetic field. Highconductivity layers of seawater and sediments shield the underlying 3D inhomogeneity. Their presence virtually does not affect changes in the standard responses of the medium used in MTS but is quite noticeable in the characteristics of the TM mode. To register them, one can use a circular electric dipole (CED) located at the surface of an ice floe. During the drift, the electric field can be measured on the ice floe using electrodes in seawater. We propose to lower the magnetic sensors beneath the ice, in seawater, because ice deformations interfere with the magnetic-field component measurements. The coordinates of the observation station during MT soundings on the ice floe in the Arctic (similarly to earlier observations at the North Pole stations) can change significantly. To take into account the effect of horizontal movements of the drifting station, we propose to complement all the recorded time series with the coordinates of measurement points. We have developed a technique for processing such data to take into account nonplane-wave effects, which can occur in the Arctic because of the proximity of ionospheric current jets. We carry out the synchronization of all observations in the investigated area, using a model of spatial and temporal field variations and data accumulation. To test our approach, we use the synthetic experimental data for the model that considers the existence of seawater, sediment, resistive crust, crustal object, and underlying mantle. We determine the crustal 3D object parameters with account of the TM-mode potential distributions at the seawater surface restored from the synthetic experimental data obtained at the drifting station during the drift. We use the Nelder–Mead method for optimization of the object characteristics. The parameters of the object become highly similar to their test values if the trajectory of the drifting station passes through an object, covering it most fully.

A New Algorithm for Generalization of Least Square Method for Straight Line Regression in Cartesian System for Fully Correlated Both Coordinates

This work presents the estimation of parameters and uncertainty of straight regression line using the least square method when both coordinates in Cartesian System XOY are affected by errors and fully correlated. The maximalization of the likelihood multivariate Gaussian function as equivalent of minimalization of objection function is derived for common vector variable Z included X and Y vectors random variable – vectors of coordinates of measurement points. In this way all kind of possible correlations are taken into account – within the metrological literature, there exist some works taking them into account. The core of the presentation is the mathematical manipulation based on linear algebra matrixes and vectors with elements of functional analysis. Any novelty claimed in this field will be carefully demonstrated. The problem is reduced to the determination of numerical one-dimensional characteristic e.g. objection function as function of slope a of straight regression line. The algorithm allows to determine numerically the covariance matrix and the coverage corridor for straight line regression. The implementation of the numerical method is applied in script running in MATLAB environment. Finally, the comparison of results based on the previous published tests are carried out.

Application of the least square method for calculating the optimal well profile

The article offers a new approach to calculating a wellbore profile of a directional well. The calculation of the well trajectory based on inclinometric studies using correlation analysis is considered. The coordinates of measurement points are calculated automatically by building a comparison table in Microsoft Excel. Based on the results of calculations, the functional relation the most fully characterizing the well path is selected. We propose the least square method for calculating the optimal well profile. According to revealed functional relation, the length of the well is determined by integration based on the calculated values of displacements. The estimation of wellbore deviation from the well profile design represented as a parabolic dependence at a certain drilling interval was performed.

Метод локального моніторингу атмосфери за допомогою безпілотних літальних апаратів

Theoretical substantiation of the method of organization of tropospheric monitoring by means of unmanned aerial vehicles with means of atmospheric monitoring installed on board as an auxiliary technical element of the method of organization of atmospheric monitoring by automated stations located on the basis of base stations of mobile operators is carried out. The analysis of liquidations of consequences of resonant accidents, and also designs and characteristics of unmanned aerial vehicles used at their liquidation is carried out. Modern types and characteristics of measuring equipment that can be installed on board unmanned aerial vehicles and used in atmospheric monitoring are considered. An algorithm for tropospheric monitoring has been developed, based on the use of unmanned aerial vehicles with state monitoring devices installed on board, for the operation of which the time during which measurements should be performed, as well as the required number and coordinates of concentration measurement points have been determined. Differs from existing solutions to the problem of determining the coordinates of measurement points using genetic algorithms. Also, the developed method of local monitoring of the atmosphere with the help of unmanned aerial vehicles equipped with means of monitoring the state of the atmosphere took into account the information delay and determined the time interval during which it is possible to perform measurements. The results obtained in the work are of most interest to the rescue services, which plan to use unmanned aerial vehicles to monitor the state of the atmosphere in emergencies, accompanied by emissions of pollutants into the atmosphere.

Research on RTK tilt position measurement method based on UKF

Aiming at coordinates of some points cannot be measured directly due to the limits of terrain and instruments in actual measurement, a novel real-time kinematic (RTK) tilt position measurement method is proposed in this study. Traditional GPS static measurement method cannot gain positioning results real time. In contrast, RTK can provide real-time 3D positioning results of stations in specified coordinate system and the positioning error is centimetre scale. Taking coordinates of points on spherical model as observation, the coordinates of measurement points are got indirectly through estimating positions of sphere centre based on unscented Kalman filter (UKF). Three schemes are designed to verify the performance of the proposed method through convergence and estimated errors. As the semi-physical simulation shows, the proposed method has better performance and is simple and easy to operate. Besides, the proposed method can smooth noise of measurement points and it can realise centimetre-level position accuracy without any auxiliary equipment, which effectively avoids measurement error caused by centering rod tilt.

Data fusion of surface normals and point coordinates for deflectometric measurements

Abstract. Measuring specular surfaces can be realized by means of deflectometric measurement systems with at least two reference planes as proposed proposed by Petz and Tutsch (2004). The results are the point coordinates and the normal direction of each valid measurement point. The typical evaluation strategy for continuous surfaces involves an integration or regularization of the measured normals. This method yields smooth results of the surface with deviations in the nanometer range but it is sensitive to systematic deviations. The measured point coordinates are robust against systematic deviations but the noise level is in the order of micrometers. As an alternative evaluation strategy a data-fusion process that combines both the normal direction and the point coordinates has been developed. A linear fitting technique is proposed to increase the accuracy of the point coordinate measurements by forming an objective functional as the mean squared misfit of the gradients with respect to the point coordinates on the one hand and to the normals on the other hand. Moreover, a constraint on the maximal change of the coordinate measurements is added to the optimization problem. To minimize to objective under the constraint a projected gradient method is used. The results show that the proposed method is able to adjust the point coordinate measurement to the measured normals and hence decrease the spatial noise level by more than an order of magnitude.

Conicity error evaluation using sequential quadratic programming algorithm

• Least-square method is employed to locate the cone roughly. • Simplified signed distance function is derived. • Simplified differential motion model of distance function is deduced. • SQP evaluation algorithm of conicity error is obtained. • The evaluation algorithm applies to cone with arbitrary position and orientation. Form error evaluation plays an important role in processing quality evaluation. Conicity error is evaluated as a typical example in this paper based on sequential quadratic programming (SQP) algorithm. The evaluation is carried out in three stages. Signed distance function from the measured points to conical surface is defined and the cone is located roughly by the method of traditional least-squares (LS) firstly; the fitted cone and the measured point coordinates are transformed to simplify the optimal mathematical model of conicity error evaluation secondly; and then optimization problem on conicity error evaluation satisfying the minimum zone criterion is solved by means of SQP algorithm and kinematic geometry, where approximate linear differential movement model of signed distance function is deduced in order to reduce the computational complexity. Experimental results show that the conicity error evaluation algorithm is more accurate, and has good robustness and high efficiency. The obtained conicity error is effective.

Analysing uncertainty contributions in dimensional measurements of large-size objects by ultrasound sensors

According to the ever-increasing interest in metrological systems for dimensional measurements of large-size objects in a wide range of industrial sectors, several solutions based on different technologies, working principles, architectures and functionalities have been recently designed. Among these, a distributed flexible system based on a network of low-cost ultrasound (US) sensors – the Mobile Spatial coordinate Measuring System (MScMS) – has been developed. This article presents a possible approach to assess the system uncertainty referring to the measured point coordinates in the 3D space, focusing on the sources of measurement uncertainty and the related propagation law.

Construction of a highly precise 3D image using human dry skulls

The purpose of this study was to use the coordinates of measurement points from the cranial specimens with normal occlusion to compare three-dimensional (3-D) images of Japanese males and females a...

The Mobile Spatial coordinate Measuring System II (MScMS-II): system description and preliminary assessment of the measurement uncertainty

According to the increasing interest in metrological systems for the dimensional measurements of large-size objects in a wide range of industrial sectors, several solutions based on different technologies, working principles, architectures, and functionalities have recently been developed. Among all, the most flexible and easily transportable solutions are those that have aroused most interest and have found greater success. In order to address the needs of Large-Scale Metrology (LSM) applications, a distributed flexible system based on a network of low-cost InfraRed (IR) sensors - the Mobile Spatial coordinate Measur- ing System II (MScMS-II) - has been developed at the Industrial Quality and Metrology Laboratory of Politecnico di Torino. This paper presents a preliminary uncertainty assessment of the system referring to the measured point coordinates in the 3D space, focusing on the sources of measurement uncertainty and the related propagation laws. A preliminary metrological characterization of MScMS-II architecture, experimentally evaluated through a system prototype, is also presented and discussed.

Identification of Principal Rigid Body Modes Under Free-Free Boundary Condition

This paper focuses on the problem of identifying all individual principal rigid body modes and the associated mass or principal inertia of moment, which can be called modal mass, of flexible structures under the free-free boundary condition with fewer multi-location excitations than the number of those modes. The rigid body mass matrix of the structure can be identified by using both the parameters of inertia, which are determined previously by a modal parameter estimation, and the coordinates of measurement points. As all rigid body properties can be obtained from the mass matrix, it becomes possible to simulate the FRFs between any two measurement points with inclusion of the contribution of rigid body motions even by only experimental modal analysis technique. First, the theory is explained. Then, a numerical simulation and two actual identifications for a plate structure and an automotive body component are carried out to demonstrate the validity and the usefulness of the theory.