scholarly journals Reliability of vehicle movement simulation results in roundabout design procedure based on the rules of design vehicle movement geometry

2021 ◽  
Author(s):  
Tamara Džambas ◽  
Vesna Dragčević ◽  
Šime Bezina ◽  
Marijan Grgić
Keyword(s):  
Path Analysis ◽  
Design Procedure ◽  
Field Tests ◽  
Test Site ◽  
Design Elements ◽  
Movement Trajectories ◽  
Simulation Results ◽  
Movement Simulation ◽  
Vehicle Movement

Previous studies have shown that a valid roundabout design approach should include a determination of design elements based on the position of design vehicle’s movement trajectories obtained by swept path analysis in early project stages, and not a conduction of swept path analysis at the end of design process. Several software which enable such significant progress in the design practice (optimal design of roundabout elements based on the results of vehicle movement simulation) are currently available on the market. Consequently, it is of great importance to know their accuracy. The reliability of vehicle movement simulation results is usually verified by field tests in which the distances between the test vehicle’s movement trajectories are measured by means of a meter, which is a dilatory and time-consuming process. Within the scope of this study, a new approach for determination of the position of test vehicle’s movement trajectories at the test site using a precise GNSS (Global Navigation Satellite System) device is described. The test vehicle was conducting a critical manoeuvre (left turn for 270°) for ten times, and the distances between its movement trajectories were determined by means of a meter and a precise GNSS device. The situation on the test site was then simulated on a computer and the assessment of the accuracy of chosen software for vehicle movement simulation was made.

scholarly journals Vehicle swept path analysis based on GPS data

2018 ◽  
Vol 45 (10) ◽  
pp. 827-839 ◽  
Author(s):  
Vladan Ilić ◽  
Dejan Gavran ◽  
Sanja Fric ◽  
Filip Trpčevski ◽  
Stefan Vranjevac
Keyword(s):  
Path Analysis ◽  
Computer Aided Design ◽  
Field Experiments ◽  
Field Tests ◽  
Vehicle Body ◽  
Gps Data ◽  
Horizontal Projection ◽  
Gps Receivers ◽  
Movement Trajectories ◽  
Vehicle Movement

Vehicle swept path analysis presents an essential step while working on at-grade intersection and roundabout designs. Following the intensive development of computer-aided design (CAD) software in the past two decades, numerous CAD-based computer programs for vehicle movement simulation have been developed and commercially distributed. The accuracy of these simulation programs is usually verified by conducting experimental field tests in which real movement trajectories of design vehicles, equipped with global positioning system (GPS) receivers, are recorded. This paper proposes an improved methodology for retrieving vehicle movement trajectories from collected GPS data. The proposed methodology reduces the trajectory inaccuracy resulting from pavement grading characteristics and the inability to accurately install GPS receivers in relation to streamlined vehicle body. Results of field experiments show that the reduction of positioning errors in the horizontal projection is not smaller than 50.0 mm compared with previous studies.

DETERMINATION OF SIZE OF PROTECTIVE ZONES TO PROVIDE SECURITY MEASURES DURING TESTS OF ARMING AND ROCKET FORCES AND ARTILLERY MATERIALON TESTING GROUND

2019 ◽  
Vol 1 (12) ◽  
pp. 55-62
Author(s):  
O. Maistrenko ◽  
M. Petrushenko ◽  
S. Nikul ◽  
Y. Sinilo
Keyword(s):  
Armed Forces ◽  
Test Site ◽  
Security Measures ◽  
Safety Measures ◽  
Protection Zones ◽  
Testing Ground ◽  
Permanent Improvement ◽  
Near Accidents

The article analyzes the possible risks that can arise when firing artillery and rocket launches. The disadvantages of the method of calculating the protection zones are identified, which taking into account will reduce the likelihood of the occurrence of abnormal situations, which can lead to tragic consequences and damage to objects adjacent to the boundary of the testing ground. Additions to the procedure for determining the protection zones of the test site in the interests of RVIA are proposed and the specified, correct sizes of these zones are provided. Development of rocket troops and artillery (RTaA) of the Armed Forces (AF) of Ukraine is impossible without a permanent improvement and modernisation of types of armament and ammunition to them, development of the new artillery systems and their ground tests. During realization of ground tests of types of armament and military technique (WME) of RTaA firing of artillery and starting of rockets is accompanied by errors or wrong acts of WME attendant and personnel or extraneous persons, the consequences of that must be envisaged, and the risk of their origin is Analysis of the battle firing, including during realization of anti-terror operation and operation of the incorporated forces on east of Ukraine row of ground tests of standards of WME RTaA test if possibility of origin of nonpermanent near-accidents during application of armament of RtaA as a result of rejection of trajectory of flight of projectile (mines) by the direction and distance from the expected targets. Mostly it happens through untaking into account of maximal rejections of meteorological and ballistic terms of firing from tabular or errors in calculations, wrong acquisition of charge, error at aiming of fighting machines, cannons, mortars. There for practice of the battle firing needs taking into account of these errors, that will give an opportunity consider ably to promo test rength security at application of armament of RAaT during testing of standards of WME. Thus, in the article certainly and possible risks that can arise up during realization of firing of artillery and starting of rockets are analysed, related to the lacks of existent methodology of realization of calculations in relation to providing of safety measures during the tests of WME RtaA. Suggestions are brought in, in relation to the improvement of methodology of realization of calculations of sizes of protective zones, that unlike existing more in detail take into account maximal deviations of terms of firing from tabular values. These suggestions for providing of safety measures it will be allowed to decrease probability of origin of situations, that can result in tragic consequences and to causing of damages to the objects that fit closely to the limits of training field. Anoffer adding to the order of determination of protective zones and given specified sizes of the sezones have an important practical value at determination of possibilities of grounds and providing of safety of testing and battle firing (starting) of RtaA.

Numerical simulation and field test study of desulfurization wastewater evaporation treatment through flue gas

2014 ◽  
Vol 70 (7) ◽  
pp. 1285-1291 ◽  
Author(s):  
Jia-jia Deng ◽  
Liang-ming Pan ◽  
De-qi Chen ◽  
Yu-quan Dong ◽  
Cheng-mu Wang ◽  
...  
Keyword(s):  
Field Test ◽  
Flue Gas ◽  
Cfd Simulation ◽  
Electrostatic Precipitator ◽  
Negative Impact ◽  
Positive Impact ◽  
Field Tests ◽  
Gas Temperature ◽  
Simulation Results ◽  
Desulfurization Wastewater

Aimed at cost saving and pollution reduction, a novel desulfurization wastewater evaporation treatment system (DWETS) for handling wet flue gas desulfurization (WFGD) wastewater of a coal-fired power plant was studied. The system's advantages include simple process, and less investment and space. The feasibility of this system has been proven and the appropriate position and number of nozzles, the spray droplet size and flue gas temperature limitation have been obtained by computational fluid dynamics (CFD) simulation. The simulation results show that a longer duct, smaller diameter and higher flue gas temperature could help to increase the evaporation rate. The optimal DWETS design of Shangdu plant is 100 μm droplet sprayed by two nozzles located at the long duct when the flue gas temperature is 130 °C. Field tests were carried out based on the simulation results. The effects of running DWETS on the downstream devices have been studied. The results show that DWETS has a positive impact on ash removal efficiency and does not have any negative impact on the electrostatic precipitator (ESP), flue gas heat exchanger and WFGD. The pH values of the slurry of WFGD slightly increase when the DWETS is running. The simulation and field test of the DWETS show that it is a feasible future technology for desulfurization wastewater treatment.

scholarly journals Determination of the Vertical Load on the Carrying Structure of a Flat Wagon with the 18–100 and Y25 Bogies

2021 ◽  
Vol 11 (9) ◽  
pp. 4130
Author(s):  
Oleksij Fomin ◽  
Alyona Lovska ◽  
Václav Píštěk ◽  
Pavel Kučera
Keyword(s):  
Mathematical Model ◽  
Fatigue Strength ◽  
Service Life ◽  
Dynamic Characteristics ◽  
Dynamic Load ◽  
Field Tests ◽  
Vertical Load ◽  
Mathcad Software ◽  
The Mathematical Model

The study deals with determination of the vertical load on the carrying structure of a flat wagon on the 18–100 and Y25 bogies using mathematic modelling. The study was made for an empty wagon passing over a joint irregularity. The authors calculated the carrying structure of a flat wagon with the designed parameters and the actual features recorded during field tests. The mathematical model was solved in MathCad software. The study found that application of the Y25 bogie for a flat wagon with the designed parameters can decrease the dynamic load by 41.1% in comparison to that with the 18–100 bogie. Therefore, application of the Y25 bogie under a flat wagon with the actual parameters allows decreasing the dynamic loading by 41.4% in comparison to that with the 18–100 bogie. The study also looks at the service life of the supporting structure of a flat wagon with the Y25 bogie, which can be more than twice as long as the 18–100 bogie. The research can be of interest for specialists concerned with improvements in the dynamic characteristics and the fatigue strength of freight cars, safe rail operation, freight security, and the results of the research can be used for development of innovative wagon structures.

Concurrent Design Forces in Structures under Three-Component Orthotropic Seismic Excitation

2002 ◽  
Vol 18 (1) ◽  
pp. 1-17 ◽  
Author(s):  
K. Anastassiadis ◽  
I. E. Avramidis ◽  
P. Panetsos
Keyword(s):  
Ground Motion ◽  
Design Procedure ◽  
Strong Motion ◽  
Response Spectra ◽  
Concurrent Design ◽  
Motion Model ◽  
Specific Point ◽  
Extreme Stress ◽  
Seismic Motion

According to the model of Penzien and Watabe, the three translational ground motion components on a specific point of the ground are statistically noncorrelated along a well-defined orthogonal system of axes p, w, and v, whose orientation remains reasonably stable over time during the strong motion phase of an earthquake. This orthotropic ground motion is described by three generally independent response spectra Sa, Sb, and Sc, respectively. The paper presents an antiseismic design procedure for structures according to the above seismic motion model. This design includes a) determination of the critical orientation of the seismic input, i.e., the orientation that gives the largest response, b) calculation of the maximum and the minimum values of any response quantity, and c) application of either the Extreme Stress Method or the Extreme Force Method for determining the most unfavorable combinations of several stress resultants (or sectional forces) acting concurrently at a specified section of a structural member.

Influence of Human Error on Structural Reliability

2017 ◽  
Author(s):  
Eric Brehm ◽  
Robert Hertle ◽  
Markus Wetzel
Keyword(s):  
Human Error ◽  
Structural Reliability ◽  
Failure Modes ◽  
Structural Model ◽  
Limit State ◽  
Design Procedure ◽  
Material Strength ◽  
Limit States ◽  
The Impact

In common structural design, random variables, such as material strength or loads, are represented by fixed numbers defined in design codes. This is also referred to as deterministic design. Addressing the random character of these variables directly, the probabilistic design procedure allows the determination of the probability of exceeding a defined limit state. This probability is referred to as failure probability. From there, the structural reliability, representing the survival probability, can be determined. Structural reliability thus is a property of a structure or structural member, depending on the relevant limit states, failure modes and basic variables. This is the basis for the determination of partial safety factors which are, for sake of a simpler design, applied within deterministic design procedures. In addition to the basic variables in terms of material and loads, further basic variables representing the structural model have to be considered. These depend strongly on the experience of the design engineer and the level of detailing of the model. However, in the clear majority of cases [1] failure does not occur due to unexpectedly high or low values of loads or material strength. The most common reasons for failure are human errors in design and execution. This paper will provide practical examples of original designs affected by human error and will assess the impact on structural reliability.

Path Following System for Cooperative Mobile Robots

2010 ◽  
Vol 166-167 ◽  
pp. 161-166
Author(s):  
Ionut Dinulescu ◽  
Dorin Popescu ◽  
Mircea Nitulescu ◽  
Alice Predescu
Keyword(s):  
Artificial Intelligence ◽  
Mobile Robots ◽  
Path Following ◽  
Path Generation ◽  
Cooperative Robots ◽  
Generation System ◽  
Robot Systems ◽  
Simulation Results ◽  
Trajectory Generator

Recent advances in the domains of social and life artificial intelligence have constituted the basis for a new discipline that studies cooperation in multi-robot systems and its utility in applications where some tasks cannot be carried out by a single robot. This paper introduces a trajectory generator which is used for determination of the most appropriate trajectory which a robot needs to track in order to perform different tasks specific to cooperative robots, such as moving in a given formation or pushing an object to a given destination. Different algorithms are described in this paper, starting from simple polyline and circular paths to complex Bezier trajectories. Simulation results of the proposed path generation system are also provided, along with the description of its implementation on real mobile robots. An implementation of real robots is also presented in this paper.

scholarly journals PENGARUH PROFITABILITAS TERHADAP NILAI PERUSAHAAN DENGAN STRUKTUR MODAL SEBAGAI MEDIATOR PADA PERUSAHAAN PEMBIAYAAN

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Ni Ketut Sulastri ◽  
Ni Ketut Surasni
Keyword(s):  
Data Analysis ◽  
Capital Structure ◽  
Path Analysis ◽  
Firm Value ◽  
Analytical Tool ◽  
Purposive Sampling ◽  
Analysis Technique ◽  
Finance Company ◽  
The Capital Structure

This study aims to analyze the effect of profitability on capital structure, the effect of capital structure on firm value, the effect of profitability on firm value and analyze the effect of profitability on firm value through the capital structure of finance companies on the IDX. This type of research is causal associative research. The population of this study is a finance company listed on the IDX, while the selected sample consists of 11 companies. Determination of samples with Purposive sampling. The data analysis technique uses Path Analysis (path analysis) and the analytical tool used is IBM SPSS 23. The results show that (1) profitability has a positive and not significant effect on capital structure (2) the capital structure has a positive and not significant effect on firm value ( 3) profitability has a positive and significant effect on firm value (4) capital structure is not able to mediate the influence of profitability on firm value.Keywords:Perusahaan Pembiayaan;Profitabilitas;Nilai Perusahaan;Struktur Modal

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