scholarly journals The development of stamp points displacement mathematical model by static tests of road structures

2021 ◽  
pp. 35-43
Author(s):  
Ivan Shuliak ◽  
◽  
Serhii Sukhonosov ◽  
Oleksand Chechuha ◽  
◽  
...  
Keyword(s):  
Mathematical Model ◽  
Displacement Sensor ◽  
Engineering Practice ◽  
Static Tests ◽  
Static Testing ◽  
Displacement Sensors ◽  
Modulus Of Deformation ◽  
Parallel Transfer ◽  
The Moment ◽  
Necessary And Sufficient

In various static stamp tests methods, both foreign and Ukrainian, it is foreseen to use a different number of sensors for stamp settlement measuring. Austrian method with three displacement sensors allows to reveal the stamp warping while loading, but it is unclear how to determine the settlement in the stamp center, when the sensor readings at the moment of warping will be completely different. The German method with a single displacement sensor is much simpler, but does not consider the stamp warping. The use of Ukrainian methodology is not appropriate at all, because two displacement sensors do not allow to observe the stamp warping. The article is focused on mathematical model for the displacement of stamp points in road structures static testing development with theoretical justification of necessary and sufficient number of sensors for stamp settlement measuring. Initially, the stamp displacement under warping in a flat deformed condition is considered as a rotation on a certain angle α and a parallel transfer. It has been established that in this case, the stamp settlement with enough accuracy for engineering practice can be measured with a single displacement sensor installed in the stamp center. In fact, the stamp can rotate not only around the axis Oy, but also around the Ox axis. Therefore, a separate mathematical model is constructed and describes the process of stamp displacement while it’s warping in a volumetric deformed condition. The developed mathematical model provides an opportunity to determine the settlement in the stamp center, necessary for the modulus of elasticity calculation or modulus of deformation in the case when the stamp at the warping moment will rotate both around the axis Oy and around the Ox axis, and the rotation angles α and β will be significant.

Conductor Galloping Prediction Method Based on MEMs 3D Dynamic Displacement Sensors

2014 ◽  
Vol 667 ◽  
pp. 328-333 ◽  
Author(s):  
Zi Guan Zhou ◽  
Wen Jing Li ◽  
Qing Wu ◽  
Yun Di Wang ◽  
Zhu Liu ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Calculated Data ◽  
Prediction Method ◽  
Maintenance Management ◽  
Wireless Sensor ◽  
Displacement Sensor ◽  
Dynamic Displacement ◽  
Displacement Sensors ◽  
Operation And Maintenance ◽  
Measured Information

Existed conductor galloping can only analyze the real-time state. There is no effective method to predict the conductor galloping state and alarm if necessary in the future. In order to solve the above problems, a new conductor galloping method based on the MEMs 3Ddynamic displacement sensing network has been proposed and realized. The MEMs dynamic displacement sensor is used to sense the distributed galloping information. The low-power wireless sensor network is deployed to transmit data back to the host quickly and realize the centralized treatment. The three-degree freedom model is built to analyze multi-dimensional displacement in the horizontal, vertical and torsional directions. Finally, the conductor galloping is predicted and early alarmed by using measured information sensed by sensors, the calculated data by mathematical model and some key parameters of future weather. The method proposed in this paper has been validated in practice. The predicted trajectory after 2 hours and the actual conductor galloping trajectory are basically identical. The deviation is less than 0.03 meters. This method realizes conductor galloping prediction. It strongly supports the operation and maintenance management of the transmission Line.

Optimizing laser triangulation displacement sensor of 3D positioning and posture using COA Based BPNN

Sensor Review ◽  
2020 ◽  
Vol 40 (1) ◽  
pp. 112-120
Author(s):  
Yassine Selami ◽  
Na Lv ◽  
Wei Tao ◽  
Hongwei Yang ◽  
Hui Zhao
Keyword(s):  
Mathematical Model ◽  
Measuring System ◽  
Displacement Sensor ◽  
Laser Triangulation ◽  
Content Type ◽  
Depth Measurement ◽  
Displacement Sensors ◽  
Wide Range ◽  
3D Positioning ◽  
The Mathematical Model

Purpose The purpose of this paper is to propose cuckoo optimization algorithm (COA)-based back propagation neural network (BPNN) to reduce the effect of the nonlinearities presented in laser triangulation displacement sensors. The 3D positioning and posture sensor allows access to the third dimension through depth measurement; the performance of the sensor varies according to the level of nonlinearities presented in the system, which leads to inaccuracies in measurement. Design/methodology/approach While applying optimization approach, the mathematical model and the relationship between the key parameters in the laser triangulation ranging and the indexes of the measuring system were analyzed. Findings Based on the performance of the parametric optimization method, the measurement repeatability reached 0.5 µm with an STD value within 0.17 µm, an expanded uncertainty of measurement was within 5 µm, the angle error variation of the object’s rotational plane was within 0.031 degrees and nonlinearity was recorded within 0.006 per cent in a full scale. The proposed approach reduced the effect of the nonlinearity presented in the sensor. Thus, the accuracy and speed of the sensor were greatly increased. The specifications of the optimized sensor meet the requirements for high-accuracy devices and allow wide range of industrial application. Originality/value In this paper, COA-based BPNN is proposed for laser triangulation displacement sensor optimization, on the basis of the mathematical model, clarifying the working space and working angle on the measurement system.

scholarly journals Modelling the impact of delaying vaccination against SARS-CoV-2 assuming unlimited vaccine supply

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Marcos Amaku ◽  
Dimas Tadeu Covas ◽  
Francisco Antonio Bezerra Coutinho ◽  
Raymundo Soares Azevedo ◽  
Eduardo Massad
Keyword(s):  
Mathematical Model ◽  
Vaccination Campaign ◽  
Vaccination Rate ◽  
Sao Paulo ◽  
The State ◽  
São Paulo ◽  
Health Authorities ◽  
The World ◽  
The Moment ◽  
The Impact

Abstract Background At the moment we have more than 177 million cases and 3.8 million deaths (as of June 2021) around the world and vaccination represents the only hope to control the pandemic. Imperfections in planning vaccine acquisition and difficulties in implementing distribution among the population, however, have hampered the control of the virus so far. Methods We propose a new mathematical model to estimate the impact of vaccination delay against the 2019 coronavirus disease (COVID-19) on the number of cases and deaths due to the disease in Brazil. We apply the model to Brazil as a whole and to the State of Sao Paulo, the most affected by COVID-19 in Brazil. We simulated the model for the populations of the State of Sao Paulo and Brazil as a whole, varying the scenarios related to vaccine efficacy and compliance from the populations. Results The model projects that, in the absence of vaccination, almost 170 thousand deaths and more than 350 thousand deaths will occur by the end of 2021 for Sao Paulo and Brazil, respectively. If in contrast, Sao Paulo and Brazil had enough vaccine supply and so started a vaccination campaign in January with the maximum vaccination rate, compliance and efficacy, they could have averted more than 112 thousand deaths and 127 thousand deaths, respectively. In addition, for each month of delay the number of deaths increases monotonically in a logarithmic fashion, for both the State of Sao Paulo and Brazil as a whole. Conclusions Our model shows that the current delay in the vaccination schedules that is observed in many countries has serious consequences in terms of mortality by the disease and should serve as an alert to health authorities to speed the process up such that the highest number of people to be immunized is reached in the shortest period of time.

scholarly journals One-relator groups and algebras related to polyhedral products

2021 ◽  
pp. 1-20
Author(s):  
Jelena Grbić ◽  
George Simmons ◽  
Marina Ilyasova ◽  
Taras Panov
Keyword(s):  
Homology Group ◽  
Homotopy Theory ◽  
Commutator Subgroup ◽  
Homology Groups ◽  
Homological Characterization ◽  
One Relator Groups ◽  
Combinatorial Condition ◽  
The Moment ◽  
Necessary And Sufficient

We link distinct concepts of geometric group theory and homotopy theory through underlying combinatorics. For a flag simplicial complex $K$ , we specify a necessary and sufficient combinatorial condition for the commutator subgroup $RC_K'$ of a right-angled Coxeter group, viewed as the fundamental group of the real moment-angle complex $\mathcal {R}_K$ , to be a one-relator group; and for the Pontryagin algebra $H_{*}(\Omega \mathcal {Z}_K)$ of the moment-angle complex to be a one-relator algebra. We also give a homological characterization of these properties. For $RC_K'$ , it is given by a condition on the homology group $H_2(\mathcal {R}_K)$ , whereas for $H_{*}(\Omega \mathcal {Z}_K)$ it is stated in terms of the bigrading of the homology groups of $\mathcal {Z}_K$ .

DIFFERENTIAL EQUATIONS FOR TRAIN STARTING WITH ELASTIC CONNECTIONS

2021 ◽  
Vol 2 ◽  
pp. 18-26
Author(s):  
I.P. POPOV
Keyword(s):  
Mathematical Model ◽  
Differential Equations ◽  
Friction Force ◽  
Static Friction ◽  
Longitudinal Vibrations ◽  
Maximum Tension ◽  
Inert Mass ◽  
The Moment ◽  
Elastic Couplings ◽  
Selection Of

The starting mode for the train is the most difficult. An effective method of pulling is the selection of coupling clearances. In this case, the cars are set in motion sequentially and the inert mass, as well as the static friction force immediately at the moment of starting, are minimal. This method has two significant drawbacks - a small fixed value of the gaps in the couplings and the shock nature of the impulse transfer. These disadvantages can be avoided by using elastically deformable couplings. The aim of this work is to construct a mathematical model of "easy" starting of a train with elastic couplings. The softening of the train start-off mode is essentially due to the replacement of the simultaneous start-off of the sections with alternate ones. To exclude longitudinal vibrations of the composition, after reaching the maximum tension of the coupling, the possibility of its harmonic compression should be mechanically blocked.

Optimization Calculation of Javelin Throwing Results

2014 ◽  
Vol 716-717 ◽  
pp. 764-766
Author(s):  
Min Jiang ◽  
Ji He Zhou
Keyword(s):  
Mathematical Model ◽  
Wind Tunnel ◽  
Initial Velocity ◽  
Angle Of Attack ◽  
Wind Tunnel Experiment ◽  
Aerodynamic Efficiency ◽  
Optimization Calculation ◽  
Computer Optimization ◽  
Necessary And Sufficient

On the basis of javelin wind tunnel experiment, we established mathematical model of javelin flight to conduct a computer optimization and got the conclusions. When the initial velocity is in the range of 25m/s-30m/s, the best throwing condition is: the throwing angle is 40°, the angle of attack is 11°. The javelin throwing condition is not zero angle of attack was necessary and sufficient for obtained aerodynamic efficiency.

scholarly journals High-Accuracy Calibration Based on Linearity Adjustment for Eddy Current Displacement Sensor

Sensors ◽  
2018 ◽  
Vol 18 (9) ◽  
pp. 2842 ◽  
Author(s):  
Wei Liu ◽  
Bing Liang ◽  
Zhenyuan Jia ◽  
Di Feng ◽  
Xintong Jiang ◽  
...  
Keyword(s):  
Eddy Current ◽  
Measurement Accuracy ◽  
Characteristic Curve ◽  
Calibration Method ◽  
High Accuracy ◽  
Output Characteristic ◽  
Displacement Sensor ◽  
Support Vector ◽  
Displacement Sensors ◽  
Calibration Accuracy

High precision position control is essential in the process of parts manufacturing and assembling, where eddy current displacement sensors (ECDSs) are widely used owing to the advantages of non-contact sensing, compact volume, and resistance to harsh conditions. To solve the nonlinear characteristics of the sensors, a high-accuracy calibration method based on linearity adjustment is proposed for ECDSs in this paper, which markedly improves the calibration accuracy and then the measurement accuracy. After matching the displacement value and the output voltage of the sensors, firstly, the sensitivity is adjusted according to the specified output range. Then, the weighted support vector adjustment models with the optimal weight of the zero-scale, mid-scale and full-scale are established respectively to cyclically adjust the linearity of the output characteristic curve. Finally, the final linearity adjustment model is obtained, and both the calibration accuracy and precision are verified by the established calibration system. Experimental results show that the linearity of the output characteristic curve of ECDS adjusted by the calibration method reaches over 99.9%, increasing by 1.9–5.0% more than the one of the original. In addition, the measurement accuracy improves from 11–25 μ m to 1–10 μ m in the range of 6mm, which provides a reliable guarantee for high accuracy displacement measurement.

scholarly journals A SIMULATION MODEL FOR ROBOT’S SLIP DISPLACEMENT SENSORS

2016 ◽  
pp. 224-236 ◽  
Author(s):  
Yuriy Kondratenko ◽  
Oleksandr Gerasin ◽  
Andriy Topalov
Keyword(s):  
Simulation Model ◽  
Field Programmable Gate Array ◽  
Hardware Implementation ◽  
Displacement Sensor ◽  
Clamping Force ◽  
Sensing System ◽  
Displacement Sensors ◽  
Field Programmable ◽  
Slip Displacement ◽  
Corrosive Environments

This paper deals with a simulation model of slip displacement sensors for the object slip signals’ registration in the adaptive robot’s gripper. The study presents the analysis of different methods for slip displacement signals detection, as well as authors’ solutions. Special attention is paid to the investigations of the developed sensor with the resistive registration element in rod type structure of sensitive elements, which is able to operate in harsh and corrosive environments. A sensing system for the object slip signals’ registration in the adaptive robot’s gripper with a clamping force correction is developed for proposed slip displacement sensor with multi-component resistive registration elements. The hardware implementation of the sensing system for slip signals’ registration and obtained results are considered in details. The simulation model of the proposed slip displacement sensor based on polytypic conductive rubber is modeled by Proteus software. The intelligent approaches with the use of a field programmable gate array (FPGA) and VHDL-model to the sensing system designing allow to define the slippage direction in slip displacement sensor based on resistive registration elements. Thus, this expands the functionality of the developed sensor.

Fault Tolerant and Nano Displacement Drive Control Method of Photoelectric Motor for Battery Electric Vehicle

2021 ◽  
Vol 16 (2) ◽  
pp. 293-302
Author(s):  
Weiping Liu ◽  
Zhaofeng Wang ◽  
Ximing Zhang ◽  
Yulin Wang ◽  
Bochun Hu ◽  
...  
Keyword(s):  
Electric Vehicle ◽  
Control Method ◽  
Displacement Sensor ◽  
Battery Electric Vehicle ◽  
Position Sensor ◽  
Low Resolution ◽  
Rotor Position ◽  
Displacement Sensors ◽  
Position Signal ◽  
Three Phase

The low-resolution photoelectric position sensor is used, that is, Hall position sensor replaces the traditional photoelectric encoder and other high-resolution position sensors to monitor the rotor position. However, because the three-phase Hall position sensor can only output six position signals, a hardware circuit design of low-resolution position sensor monitoring rotor position signal is proposed. Meanwhile, nanotechnology has been introduced in the study of micro drive of battery electric vehicle (BEV). BEV driver has some disadvantages such as hysteresis, creep and nonlinearity, which seriously affects its application in nano environment. A nano displacement sensor is designed for the characteristics of BEV driver. The nonlinear problem of micro driver is solved through the closed-loop control of position feedback. In the test, through the verification of rotor position and current waveform, it can be proved that the method based on photoelectric position sensor and rotor position signal monitoring can ensure the low deviation of rotor position calculation and correct output signal of three-phase photoelectric position sensor. The decoupling performance of vector control is verified by 3/2 transformation. In the displacement detection of micro driver, the designed nano displacement sensor has higher resolution and its performance is better than that of the previous three generations of displacement sensors.

scholarly journals The issue of loading the material in a vibro-impact grinder

2019 ◽  
Vol 109 ◽  
pp. 00024 ◽  
Author(s):  
Olena Fedoskina ◽  
Valerii Fedoskin ◽  
Anastasiia Loginova
Keyword(s):  
Mathematical Model ◽  
Phase Angle ◽  
Basic Principles ◽  
Working Chamber ◽  
Force Loading ◽  
New Class ◽  
Power Loading ◽  
The Moment ◽  
Rotational Oscillations

The article discusses the basic principles of force loading of a material in a vibro-impact grinder with a vertical and inclined working chamber. It is shown that in a grinder with a vertical working chamber the control of the material loading is limited by the presence of a relationship between the vertical and rotational oscillations of the jaws. Vibro-impact grinder with an inclined working chamber represents a new class of machines. A mathematical model of the process of interaction of the jaw with a piece of material when moving it in the working chamber is presented. Equations and graphical dependencies are obtained, which determine the phase angle of the moment of clamping the piece in the working chamber. The modes of power loading of the material in the working chamber were analyzed.

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