Measurement of the angular motion parameters of the mirror of the scanning device

2021 ◽  
pp. 3-7
Author(s):  
Petr A. Pavlov ◽  
Elena M. Ivashchenko
Keyword(s):  
Angular Velocity ◽  
Angular Position ◽  
Low Frequency ◽  
Frequency Region ◽  
Angular Motion ◽  
Main Attention ◽  
Scanning Angle ◽  
Scanning Device ◽  
Environmental Monitoring System

A scanning device for a space-based environmental monitoring system has been investigated. The main attention is paid to the study of the parameters of the angular motion of the mirror of the scanning device, the uniformity of rotation of which largely determines the quality of the image of the Earth's surface. The principle and results of measuring the parameters of the mirror rotation carried out in a wide angular range are considered. The measurements were performed using a dynamic goniometer-autocollimator, which has been calibrated at the State Standard of Plane Angle Unit GET 22-2014. The repeatability of the average angular velocity of the scanning device mirror and the repeatability of the initial scanning angle are calculated. Nonstationarity in mathematical expectation and variance in random deviations of the angular motion of the mirror from the linear law of scanning is noted. The use of wavelet analysis revealed the frequency of excitation of oscillations in the low-frequency region of the spectrum. The possibility of using the a dynamic goniometer-autocollimator for measuring not only the angular position of the scanning device mirror, but also the angular velocity is shown.

Performance of the combined hydropneumatic isolations on improving vibration of vibratory roller cab: Experiment and simulation

2021 ◽  
pp. 095745652199983
Author(s):  
Huaxiang Zhou ◽  
Vanliem Nguyen ◽  
Xiaoyan Wu
Keyword(s):  
Time Domain ◽  
Low Frequency ◽  
Nonlinear Damping ◽  
Elastic Stiffness ◽  
Frequency Region ◽  
Ride Quality ◽  
Stiffness Parameter ◽  
Power Spectral ◽  
The Time Domain

This study, based on preeminent characteristics of both the pneumatic and hydraulic isolations, combined hydropneumatic isolations (CHPIs), is proposed for improving the cab ride quality of the vibratory rollers in low-frequency domain. A 3D dynamic model and mathematical model of the cab isolations and the vibratory rollers are established to simulate CHPI’s characteristics under the excitations of the off-road terrain and vibratory drum at 28 Hz and 35 Hz. To enhance the reliability of research results, vehicle’s mathematical models are also verified via the experimental investigation. The effectiveness of CHPIs on ameliorating the cab’s ride quality is then analyzed via two indicators of the power spectral density (PSD) acceleration on the frequency region and root-mean-square (RMS) acceleration on the time domain of the cab and operator seat. It is found that with the combination of the high-elastic stiffness parameter and high nonlinear damping coefficient of CHPIs using for the vehicle’s cab isolations, the results of the cab’s ride quality are greatly improved compared with other cab isolations in the well-known existing works.

scholarly journals УПРАВЛЕНЧЕСКИЕ МОДЕЛИ УГЛОВОГО ДВИЖЕНИЯ КОРОМЫСЛА С ВИНТОВЫМИ ЭЛЕКТРОПРИВОДАМИ

2020 ◽  
pp. 4-14
Author(s):  
Анатолий Степанович Кулик ◽  
Евгений Валерьевич Филиппович ◽  
Константин Юрьевич Дергачев ◽  
Сергей Николаевич Пасичник ◽  
Юрий Александрович Немшилов
Keyword(s):  
Angular Velocity ◽  
Automatic Control ◽  
State Space ◽  
Mathematical Description ◽  
Angular Position ◽  
Control Object ◽  
Angular Motion ◽  
Lagrangian Formalism ◽  
Frequency Domains ◽  
Analysis And Synthesis

The subject of study in the article is the forming models' process for the angular motion of the rocker with screw electric actuators. The purpose is to develop the approach to the simplest models formation for the angular motion of the rocker with screw electric actuators as the automatic control object. Tasks: to form the physical model of rocker with screw electric actuators. Using the Lagrangian formalism develop the non-linear mathematical description of the angular motion process of a rocker with screw electric actuators. To obtain the linearized mathematical description of the automatic control object in form of state space in the cases when one sensor (angular position) and two sensors (angular position and angular velocity of the rocker) are used. To obtain the description of the automatic control object in the frequency domain using Laplace transforms. To form graphic models of the automatic control object using structural diagrams in the time and frequency domains. To analyze the functional properties of the automatic control object: stability, controllability, observability, structural and signal diagnosability in the cases when one sensor (angular position) and two sensors (angular position and angular velocity of the rocker) are used. To formulate the conditions for using mathematical descriptions as mathematical models of the automatic control object. The methods used are the Lagrange method, analytical linearization, state space, Laplace transform, Lypunov, Kalman criteria, diagnosability. The following results were obtained: the approach to the formation of the simplest models for the angular motion of a rocker with screw electric actuators as an object of automatic control for solving specific problems of analysis and synthesis was formed. Conclusions. The scientific novelty lies in the formation of the approach to the formation of the simplest control models for the angular motion of the rocker with screw electric actuators which differs from the known completeness of accounting for the acting forces and moments.

Dynamics of the processes in metal machining

1998 ◽  
Vol 2 ◽  
pp. 115-122
Author(s):  
Donatas Švitra ◽  
Jolanta Janutėnienė
Keyword(s):  
High Frequency ◽  
Machine Tools ◽  
Metal Cutting ◽  
Cutting Tool ◽  
Low Frequency ◽  
Metal Cutting Machine ◽  
Cutting Machine ◽  
Metal Machining

In the practice of processing of metals by cutting it is necessary to overcome the vibration of the cutting tool, the processed detail and units of the machine tool. These vibrations in many cases are an obstacle to increase the productivity and quality of treatment of details on metal-cutting machine tools. Vibration at cutting of metals is a very diverse phenomenon due to both it’s nature and the form of oscillatory motion. The most general classification of vibrations at cutting is a division them into forced vibration and autovibrations. The most difficult to remove and poorly investigated are the autovibrations, i.e. vibrations arising at the absence of external periodic forces. The autovibrations, stipulated by the process of cutting on metalcutting machine are of two types: the low-frequency autovibrations and high-frequency autovibrations. When the low-frequency autovibration there appear, the cutting process ought to be terminated and the cause of the vibrations eliminated. Otherwise, there is a danger of a break of both machine and tool. In the case of high-frequency vibration the machine operates apparently quiently, but the processed surface feature small-sized roughness. The frequency of autovibrations can reach 5000 Hz and more.

Estimating the Quality of Thermionic Cathodes for Microwave Vacuum Tubes Using the Low-Frequency Noise Parameters

Vestnik MEI ◽  
2018 ◽  
Vol 5 (5) ◽  
pp. 120-127
Author(s):  
Mikhail D. Vorobyev ◽  
◽  
Dmitriy N. Yudaev ◽  
Andrey Yu. Zorin ◽  
◽  
...  
Keyword(s):  
Low Frequency ◽  
Frequency Noise ◽  
Low Frequency Noise ◽  
Noise Parameters ◽  
Thermionic Cathodes ◽  
Vacuum Tubes

scholarly journals Analysis of ergonomic and unergonomic human lifting behaviors by using Inertial Measurement Units

2017 ◽  
Vol 3 (1) ◽  
pp. 7-10 ◽  
Author(s):  
Jan Kuschan ◽  
Henning Schmidt ◽  
Jörg Krüger
Keyword(s):  
Quality Of Life ◽  
Machine Learning ◽  
Angular Velocity ◽  
Musculoskeletal System ◽  
Occupational Diseases ◽  
Inertial Measurement Units ◽  
Inertial Measurement ◽  
Measurement Units ◽  
Main Components

Abstract:This paper presents an analysis of two distinct human lifting movements regarding acceleration and angular velocity. For the first movement, the ergonomic one, the test persons produced the lifting power by squatting down, bending at the hips and knees only. Whereas performing the unergonomic one they bent forward lifting the box mainly with their backs. The measurements were taken by using a vest equipped with five Inertial Measurement Units (IMU) with 9 Dimensions of Freedom (DOF) each. In the following the IMU data captured for these two movements will be evaluated using statistics and visualized. It will also be discussed with respect to their suitability as features for further machine learning classifications. The reason for observing these movements is that occupational diseases of the musculoskeletal system lead to a reduction of the workers’ quality of life and extra costs for companies. Therefore, a vest, called CareJack, was designed to give the worker a real-time feedback about his ergonomic state while working. The CareJack is an approach to reduce the risk of spinal and back diseases. This paper will also present the idea behind it as well as its main components.

Incoherent inelastic neutron scattering from polyacetylenes in the low-frequency region

1985 ◽  
Vol 10 (4) ◽  
pp. 293-295 ◽  
Author(s):  
M. Tasumi ◽  
I. Harada ◽  
H. Takeuchi ◽  
H. Shirakawa ◽  
S. Suzuki ◽  
...  
Keyword(s):  
Neutron Scattering ◽  
Inelastic Neutron Scattering ◽  
Low Frequency ◽  
Inelastic Neutron ◽  
Frequency Region

Investigations of the Optical Properties of LaNi5 and LaNi4.5Sn0.5

2013 ◽  
Vol 321-324 ◽  
pp. 495-498 ◽  
Author(s):  
Dong Chen ◽  
Chao Xu
Keyword(s):  
Experimental Data ◽  
Refractive Index ◽  
Optical Properties ◽  
Density Functional ◽  
Low Frequency ◽  
Potential Method ◽  
Frequency Region ◽  
Functional Theory ◽  
The Density Functional Theory ◽  
Pseudo Potential

The reflectivity, loss function, refractive index, extinction coefficient and dielectric function of the LaNi5and LaNi4.5Sn0.5intermetallic compounds are investigated through the plane-wave pseudo-potential method based on the density functional theory. The effects of Sn impurity are discussed and some interesting features are found in the low frequency region. Some important optical properties such as static dielectric constant and static refractive index are obtained. The equation [n (0)]2=ε1(0)is satisfied according to our calculation, which indicates that our results are correct and reasonable. Nevertheless, the calculated results need to be testified in the future due to the lack of experimental data.

Anderson-Stuart Model to Analyze AC and DC Conductivity of Lithium Zinc-Silicate Glass / Glass-Ceramics

2007 ◽  
Vol 280-283 ◽  
pp. 919-924
Author(s):  
M.S. Jogad ◽  
V.K. Shrikhande ◽  
A.H. Dyama ◽  
L.A. Udachan ◽  
Govind P. Kothiyal
Keyword(s):  
High Frequency ◽  
Glass Ceramics ◽  
Low Frequency ◽  
Frequency Region ◽  
Dc Conductivity ◽  
Frequency Range ◽  
High Frequency Region ◽  
Dc Conductivities ◽  
Conductivity Variation ◽  
Different Temperatures

AC and DC conductivities have been measured by using the real (e¢) and imaginary (e¢¢) parts of the dielectric constant data of glass and glass-ceramics (GC) at different temperatures in the rage 297-642K and in the frequency range 100 Hz to 10 MHz. Using Anderson –Stuart model, we have calculated the activation energy, which is observed to be lower than that of the DC conductivity. The analysis for glass/glass-ceramics indicates that the conductivity variation with frequency exhibits an initial linear region followed by nonlinear region with a maximum in the high-frequency region. The observed frequency dependence of ionic conductivity has been analyzed within the extended Anderson–Stuart model considering both the electrostatic and elastic strain terms. In glass/glassceramic the calculations based on the Anderson-Stuart model agree with the experimental observations in the low frequency region but at higher frequencies there is departure from measured data.

Vibronic side bands of Sm2+ in alkali halides

1969 ◽  
Vol 47 (17) ◽  
pp. 1757-1767 ◽  
Author(s):  
M. Buchanan ◽  
E. J. Woll Jr.
Keyword(s):  
Low Frequency ◽  
Alkali Halides ◽  
Frequency Region ◽  
Defects In Crystals ◽  
Side Band

The calculation of vibronic side bands of defects in crystals is discussed. A model for the deformation of the lattice about a Sm2+ defect in alkali halides and side-band calculations on this model for KBr and KCl containing Sm2+ are compared with experimentally observed side bands. Improvements, particularly in the low frequency region, are found over the calculations assuming no deformation.

Sign in / Sign up

Export Citation Format

Share Document