MODELING OF SOME DYNAMIC CHARACTERISTICS OF TECHNOLOGICAL MACHINES OF THE ROAD-BUILDING COMPLEX

2021 ◽  
pp. 85-92
Author(s):  
Владимир Кириллович Маршаков ◽  
Александр Давыдович Кононов ◽  
Андрей Александрович Кононов ◽  
Владимир Исламович Гильмутдинов
Keyword(s):  
Dynamic Characteristics ◽  
Dynamic Systems ◽  
Transfer Functions ◽  
Soil Surface ◽  
Damping Properties ◽  
Work Processes ◽  
The Road ◽  
Operator Form ◽  
Reduce Emissions ◽  
Machine Operator

Рассмотрены варианты моделирования управления мобильными технологическими машинами строительного комплекса для различных задач автоматизации рабочих процессов с целью уменьшения выбросов в атмосферу за счет сокращения расхода топлива. Представлены возможные схемы снижения вредных вибрационных воздействий на оператора машины. На основе анализа динамических характеристик в операторной форме и с учетом передаточных функций, рассмотрены требования к подвеске технологической машины, повышающие защиту машиниста от воздействия вибраций при автоматическом управлении рабочими процессами. Приведены функциональные схемы динамических систем, позволяющие учитывать изменение упругих и демпфирующих свойств обрабатываемой поверхности грунта. We considered some variants of modeling control of mobile technological machines of the construction complex for various tasks in automation of work processes in order to reduce emissions into the atmosphere by reducing fuel consumption. We presented as well possible schemes for reducing harmful vibration effects on the machine operator. Being based on the analysis of dynamic characteristics in the operator form and taking into account the transfer functions, we considered the requirements for the suspension of a technological machine. This increases the protection of the driver from the effects of vibrations during automatic control of work processes. Functional schemes of dynamic systems are given, which allows us to take into account changes in the elastic and damping properties of the processed soil surface.

scholarly journals Measures to optimize traffic and the environment. Calculations of environmental safety on a given section of the Rostov-on-Don road network

2020 ◽  
pp. 68-77
Author(s):  
R. S. Durov ◽  
◽  
E. V. Varnakova ◽  
K. O. Kobzev ◽  
◽  
...  
Keyword(s):  
Road Network ◽  
Road Transport ◽  
Environmental Safety ◽  
Environmental Indicators ◽  
Nox Emissions ◽  
The Road ◽  
Before And After ◽  
Reduce Emissions ◽  
On The Road ◽  
State Of The Environment

Introduction. One of the most pressing socio-economic problems is the state of the environment, which affects the living conditions of many people. The article deals with the problem areas of the intersection of 20-ya Liniya street – Sholokhov Avenue in Rostov-on-Don. Problem Statement. The purpose of this paper is to improve environmental safety at the intersection of 20-ya Liniya street – Sholokhov Avenue in Rostov-on-Don by reducing emissions from road transport through the proposed measures to reorganize traffic on this section of the road network. Theoretical Part. The article provides an assessment of environmental and road safety on the road network section before applying the proposed measures. The measures are listed and justified that would help improve the conditions for road transport at the selected intersection and reduce emissions from road transport, which would improve environmental safety. The calculation of environmental indicators was made after the proposed measures to reduce NOx emissions by cars. Conclusion. The article analyzes the environmental indicators before and after the events, and then compares them. Based on the analysis and calculations, it is determined how much the proposed measures to optimize traffic will help reduce NOx emissions by cars.

scholarly journals Research on Heat Transfer Dynamic Characteristics of Composite Layer Based on Laplace Transform

2019 ◽  
Author(s):  
Chunyu Xu ◽  
Junhua Lin ◽  
Wenhao Liu ◽  
Yuanbiao Zhang
Keyword(s):  
Heat Transfer ◽  
Composite Materials ◽  
Temperature Distribution ◽  
Transfer Function ◽  
Dynamic Characteristics ◽  
Transfer Functions ◽  
Composite Layer ◽  
Engineering Application ◽  
Second Order ◽  
Inverse Transformation

This paper predict and effectively control the temperature distribution of the steady-state and transient states of anisotropic four-layer composite materials online, knowing the density, specific heat, heat conductivity and thickness of the composite materials. Based on the transfer function, a mathematical model was established to study the dynamic characteristics of heat transfer of the composite materials. First of all, the Fourier heat transfer law was used to establish a one-dimensional Fourier heat conduction differential equation for each composite layer, and the Laplace transformation was carried out to obtain the system function. Then the approximate second-order transfer function of the system was obtained by Taylor expansion, and the Laplace inverse transformation was carried out to obtain the transfer function of the whole system in the time domain. Finally, the accuracy of the simplified analytical solutions of the first, second and third order approximate transfer functions was compared with computer simulation. The results showed that the second order approximate transfer functions can describe the dynamic process of heat transfer better than others. The research on the dynamic characteristics of heat transfer in the composite layer and the dynamic model of heat transfer in composite layer proposed in this paper have a reference value for practical engineering application. It can effectively predict the temperature distribution of composite layer material and reduce the cost of experimental measurement of heat transfer performance of materials.

The Control of Multi-Bending: A Flexible Method to Fabricate Complex Structural Parts

1994 ◽  
Author(s):  
Jack X. Luo ◽  
Kim A. Stelson
Keyword(s):  
Process Model ◽  
Transfer Functions ◽  
Control Method ◽  
Dimensional Accuracy ◽  
High Productivity ◽  
Bending Process ◽  
Shape Errors ◽  
Complex Structural ◽  
Structural Parts ◽  
Machine Operator

Abstract The CNC multi-axis bending process can achieve high productivity and flexibility over conventional forming processes for fabricating long slender structural components of arbitrary shape. However, generating a CNC program to produce an accurate part shape is currently a laborious procedure involving trial-and-error by the machine operator. A systematic method has been developed to replace the manual control method and increase the dimensional accuracy. The concept of an intrinsic representation from differential geometry is applied as a basis to represent the part shape and develop the process model. The feedback control is derived from two transfer functions that represent the bending and twisting processes. By applying shape errors to the inverse transfer functions, incremental control commands can be determined and used to improve the control performance. Experimental results have demonstrated that shape errors decrease on subsequent iterations.

Vehicle-Bridge Coupled Vibration on Concrete-Filled Steel Tubular Arch Bridge

2011 ◽  
Vol 90-93 ◽  
pp. 1106-1111
Author(s):  
Hong Xia Tan ◽  
Zheng Qing Chen
Keyword(s):  
Impact Factor ◽  
Cross Sections ◽  
Dynamic Characteristics ◽  
Impact Factors ◽  
Arch Bridge ◽  
The Road ◽  
Moving Vehicles ◽  
Cfst Arch Bridge ◽  
Road Surface Roughness ◽  
The Impact

This paper studies the dynamic response and the impact factor of the concrete-filled steel tubular (CFST) arch bridge named Hejiang River Bridge under the moving vehicles. Research shows that the impact factor of CFST arch bridge at the vault and 1/4 arch rib is greatly influenced by the road surface roughness (RSR), and it is increased with the grade of RSR increases, meanwhile it is different at apiece section position of the arch bridge. The impact factor doesn't vary monotonically with the speed of vehicle, it appears the maximum when the speed of vehicle is between 20-25 km/h and 35-50 km/h, and the impact factors of different cross-sections are not just the same with the changing regularity of speed. Therefore, the dynamic characteristics of different structural components should be calculated in designing CFST arch bridge for discrepant dynamic characteristics of various constructional elements.

Experimental Research on Dynamic Characteristics of a Rolling Agricultural Tire (Influence of Running Condition)

2013 ◽  
Author(s):  
Katsuhide Fujita ◽  
Takashi Saito ◽  
Mitsugu Kaneko
Keyword(s):  
Natural Frequency ◽  
Dynamic Behavior ◽  
Experimental Research ◽  
Dynamic Characteristics ◽  
Excitation Frequency ◽  
Road Surface ◽  
Natural Mode ◽  
The Road ◽  
On The Road ◽  
Agricultural Machines

When agricultural machines are operated on pavements, the vibration and noise caused by the interaction between the tire lugs and the road surface are inevitable. In conventional studies, it is considered that the dynamic behavior of a rolling agricultural tire is influenced by the vibration characteristics of the tire. Resonance occurs when the lug excitation frequency of the tire, which is defined as the lug number multiplied by the number of revolutions of the tire, becomes equal to the natural frequency of the tire. In other words, the rolling tire shows large vibrations in the direction of the natural mode corresponding to the natural frequency of the tire. However, in the conventional equipment, the diameter of the drum is smaller than that of the tire. Therefore, the real running condition on the road was not realized by the rolling test using the conventional equipment. In this study, a new equipment is produced to realize the running condition in the rolling test. The dynamic and vibratory characteristics of operating agricultural machine are investigated by using this new equipment. The obtained results are compared to the conventional ones and the influence of the running condition on dynamic characteristics of rolling tire is investigated.

Evaluation of Dynamic Characteristics of Masonry Arch Bridges: Linking Full-Scale Experiment and FEM Modeling

2010 ◽  
Vol 133-134 ◽  
pp. 605-610 ◽  
Author(s):  
Joanna M. Dulinska
Keyword(s):  
Dynamic Characteristics ◽  
Natural Frequencies ◽  
Spectral Density Function ◽  
Fem Modeling ◽  
Masonry Arch ◽  
The Road ◽  
Power Spectral ◽  
Impulse Load ◽  
Scale Experiment ◽  
Arch Bridges

The paper presents calculated and experimentally determined dynamic characteristics of masonry arch bridges. Two bridges were considered: the road viaduct at Zaborow and the bridge at Kamienica Dolna (South Poland). Finite element models were built considering all parts of the structures: arch, spandrel walls, fill, soil-structure interaction. For verification of calculations in situ investigations of dynamic characteristics of bridges were conducted. As a basic ways of realization of dynamic loads impulse load (drop of a lorry wheels from a threshold) as well as kinematic excitation (train passage under the viaduct) were applied. For determination of natural frequencies power spectral density function and transfer function of measured signals were applied. Basing upon the recorded vibrations the value of logarithmic decrement of damping was evaluated. The results of measured and calculated natural frequencies were compared. With regard to the degree of complexity of structures the differences between experimental and computational results can be accepted.

Dynamics and control performance of hard disk drives with passive dampers

2004 ◽  
Vol 218 (12) ◽  
pp. 1555-1568 ◽  
Author(s):  
L M Xu ◽  
N Guo ◽  
S Zeng ◽  
R M Lin ◽  
H Du
Keyword(s):  
Dynamic Characteristics ◽  
Transfer Functions ◽  
Hard Disk Drives ◽  
Hard Disk ◽  
Data Access ◽  
Open Loop ◽  
Structure Design ◽  
Disk Drives ◽  
Phase Loss ◽  
Dynamics And Control

The residual vibration is one of the primary mechanical problems that affect the dynamic characteristics of the head actuator assembly in hard disk drives, and the data access speed and positioning resolution. A discrete damping device has been developed to suppress the quasi-rigid-body mode and a reduction of 10 dB in amplitude is shown possible. The servo performance of the head actuator assembly with and without the damping device is presented in this paper, together with the measurement and prediction of the dynamic characteristics. Both closed- and open-loop transfer functions of the plant are measured in the actual operating environment on a servo test stand and compared with the simulation. It is found that the use of passive damping in the structure design allows for a greater margin of error at the crossover frequency since less phase loss results when notch filters are used, thus improving the stability robustness in feedback control.

Identification in Rotordynamics: Model-Based vs. Direct Measurements

2009 ◽  
Author(s):  
Qingyu Wang ◽  
Brian Pettinato ◽  
Eric Maslen
Keyword(s):  
Analytical Model ◽  
Direct Measurement ◽  
Dynamic Characteristics ◽  
Measurement Method ◽  
Transfer Functions ◽  
Subsequent Paper ◽  
Quality Estimation ◽  
Model Based ◽  
Equation Solving ◽  
Direct Measurement Method

In a rotor-bearing system, there are usually some under- or unmodeled components, such as foundations and seals. Identifying the dynamic characteristics of these components often requires both an analytical model and test data due to the working conditions, such as running speed above the first bending mode and non-collocation measurements. The existing methods always identify the dynamic characteristics by solving the equations of motion at discrete frequencies of the measured frequency response functions (FRFs). They have two problems: first, the physical background of the identification is buried in the equation solving process, and second, there is no quality estimation of the identified result. This paper discusses the first problem which is the equation solving process. The second problem, quality estimation, is discussed in a subsequent paper [1]. This paper reveals that model-based identification is the interconnection of certain transfer functions. These transfer functions are either generated from an analytical model (the common model-based method), or directly measured (direct measurement method). The process of both these methods is then illustrated by use of experimental data. A novel seal test design is proposed based on the idea of the direct measurement method. Identification under complex situations is also considered as complementary to the main content, such as different input/output locations. The conditions for identifiability are given.

Research on the Dynamic Characteristics of Switching Power Supply

2013 ◽  
Vol 389 ◽  
pp. 542-549
Author(s):  
Jie Xi Zhang ◽  
Yan Cheng Liu ◽  
Qin Jin Zhang ◽  
Jun Jie Ren ◽  
Si Yuan Liu
Keyword(s):  
Dynamic Characteristics ◽  
Transfer Functions ◽  
Input Voltage ◽  
Green Energy ◽  
Switching Power Supply ◽  
Pv System ◽  
Response Characteristics ◽  
Switching Power ◽  
Key Points ◽  
And Control

In the fields of using green energy such as PV system and Wind power system, the step-up DC-DC converter, witch is used to convert the power, is now attracting more and more attention. The response characteristics and stability of one are key points for the performance of the whole system. However, it is complex to analyze the dynamic characteristics and control design. In this paper, the dynamic model of full-bridge DC-DC converter is presented, and transfer functions of the converter are derived by using state-space averaging method. And then the improved PI controller is designed. Finally, a laboratory prototype circuit with input voltage 220V, output voltage 600V is implemented and results are shown to confirm the validity of the designed switching device.

scholarly journals Dynamic Characteristics in the Design of Maglev Suspensions

1994 ◽  
Vol 208 (1) ◽  
pp. 33-41 ◽  
Author(s):  
R Goodall
Keyword(s):  
Dynamic Characteristics ◽  
Transfer Functions ◽  
Controller Design ◽  
Design Method ◽  
Vehicle Speed ◽  
Passenger Comfort ◽  
Operational Conditions ◽  
Second Stage ◽  
Maglev Vehicle

The paper reviews the essential functions which apply to any kind of suspension, and distinguishes between the various inputs to which a suspension is subjected. These are used to assess the particular characteristics of an electromagnetically suspended (Maglev) vehicle, and to identify considerations which have important implications for the controller design, irrespective of the design method. Some general equations are developed which interrelate the vehicle speed, the quality of the track and the passenger comfort requirements, and these are used to identify operational conditions for which a second stage of suspension becomes necessary (that is, in addition to that provided by the magnets). The importance of understanding the suspension's response to deterministic track inputs is also highlighted. Although the paper is directed towards Maglev, the analysis is strongly based upon a consideration of the suspension transfer functions, and so many of the principles are applicable to actively controlled supensions in general.

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