Mathematical model of capacitance micromechanical accelerometer in static and dynamic operating modes

Monitoring and early diagnosis systems, on which the protection function of both hydroturbines and auxiliary power equipment rely, are becoming increasingly relevant. One of the most promising methods of technical control and diagnostics of hydo units is the analysis of their vibro-acoustic characteristics. But a significant technical problem that arises in the construction of such systems is the limited use of known sensors of vibration velocity and vibration displacement due to the fact that the rotary speed of hydro units is usually below the lower limit of operation of sensors of this type. One of the promising ways to solve this problem is using capacitive micromechanical accelerometers. However, the existing mathematical models describing this type of accelerometers have low accuracy, which limits their practical using. The mathematical models of the capacitive micromechanical accelerometer for static and dynamic modes of operation are developed in this article. It was established that this accelerometer has a constant sensitivity, therefore its static characteristic is linear. It is shown that in the dynamic mode of operation of a capacitive micromechanical accelerometer has a dynamic error component, the cause of which is its own displacement of the moving part of the sensor, which is due to the inertial properties of the moving part and elastic properties of stretch marks. The mathematical dependence of the absolute dynamic error of the capacitive micromechanical accelerometer is obtained, the removal of w

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Models and Algorithms of Adaptive Animal Flow Control in Rotary Milking Parlors

Acta Universitatis Agriculturae et Silviculturae Mendelianae Brunensis ◽

10.11118/actaun201967061465 ◽

2019 ◽

Vol 67 (6) ◽

pp. 1465-1484

Author(s):

Vladimir V. Kirsanov ◽

Andrey Y. Izmaylov ◽

Yakov P. Lobachevsky ◽

Oksana A. Tareeva ◽

Sergey N. Strebulyaev ◽

...

Keyword(s):

Mathematical Models ◽

High Performance ◽

Dairy Farm ◽

Computing System ◽

Scientific Basis ◽

Idle Time ◽

Functional Connection ◽

Operating Modes ◽

Nizhny Novgorod Region ◽

Physiological Characters

The study addresses the influence of milking duration of individual cows on the performance of conveyor-like rotary milking parlors and seeks to optimize their operation parameters and operating modes. The observational experiment was conducted in the Zhdanovsky Farm in Nizhny Novgorod Region, Russia. The dairy farm had a herd of 600 cows, divided into 10 groups by physiological characters and milk yield, and operated a 36 point milking parlor. Distribution of milking time of individual cows was studied using statistical analysis methods. The cyclogram of parlor operation and the functional connection of main parameters were analyzed using Maple analytical computing system, including its standard libraries and functions. The trends in idle time, which occurs due to undermilking of animals in one turn of the parlor, were studied. The idle time can result in overestimation of the number of stalls or decrease in the nameplate performance of the milking parlor by 30–40% from 120 to 93 cows per hour. Mathematical models, taking into account the influence of the milking time of individual animals (2 to 17 minutes) on the parameters of parlor operation, were developed. The algorithms of adaptive control over the rotational speed were proposed to minimize idle time in parlor operation and maintain the nameplate performance. The mathematical models, control algorithms and developed software can serves as a scientific basis for new designs of high-performance rotary milking parlors.

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Simulation of water supply networks using modern means of information technology

E3S Web of Conferences ◽

10.1051/e3sconf/20184400076 ◽

2018 ◽

Vol 44 ◽

pp. 00076

Author(s):

Jerzy Kotowski ◽

Jacek Oko ◽

Monika Żygadło

Keyword(s):

Information Technology ◽

Water Supply ◽

Mathematical Models ◽

Computer Technology ◽

Technical Problem ◽

Supply Network ◽

Supply Networks ◽

Water Supply Network ◽

Water Supply Networks

We present in turn the development of computer technology from the beginning of its creation on our planet. Then we discuss the development of information technology at our university. At the end, we present a selected technical problem which is the task of simulation of the water supply network. We present mathematical models of these issues and algorithms for their solutions requiring the use of a computer.

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Simulation of the dynamic processes of a low-capacity combine harvester movement

E3S Web of Conferences ◽

10.1051/e3sconf/202016406009 ◽

2020 ◽

Vol 164 ◽

pp. 06009

Author(s):

Zakhid Godzhaev ◽

Sergey Senkevich ◽

Victor Kuzmin ◽

Ekaterina Ilchenko ◽

Mikhail Chaplygin ◽

...

Keyword(s):

Software Package ◽

Vibration Velocity ◽

Maximum Deviation ◽

Vibration Displacement ◽

Small Areas ◽

Directional Stability ◽

Different Types ◽

Direction Of Movement ◽

Combine Harvester ◽

Vertical Vibrations

To automate the process of harvesting crops, different types of harvesting machines are required. The most common type of machines used to automate ingathering are harvesters. The use of harvesters for collecting grain crops is rational in fields from 2 hectares. On smaller areas it is not profitable and difficult to apply. For applications in small areas, low-capacity harvesters with a throughput of the thresher up to 1 kg/s (small-sized) may be suitable. The purpose of this study is to analyze the cushioning mass control system of a low-capacity unmanned combine harvester using computer simulation, as well as the simulation of directional stability and turning. To calculate vertical vibrations in the Matlab/Simulink software package, a model of a cushioning system for a wheeled agricultural combine was prepared. In the same software package, simulation of directional stability and turning implementation was carried out. The parameters of vibration displacement, vibration velocity and acceleration, as well as the vibration frequency indicators on the operator's seat are determined. Comparison of the simulation results of the initial and corrected direction of movement of the harvester showed that for this model the maximum deviation from the planned path is a maximum of 10%, which is within acceptable limits. The maximum deviation of the harvester from the course does not exceed the permissible values, which is acceptable accuracy to ensure directional stability.

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Comparison of Piezoelectric Structural Damping Based on Velocity Controlled Switching and Pulse Width Modulation Switching Circuits

Volume 12: Vibration, Acoustics and Wave Propagation ◽

10.1115/imece2012-86521 ◽

2012 ◽

Cited By ~ 1

Author(s):

Dejan Vasic ◽

Yuan-Ping Liu ◽

François Costa

Keyword(s):

Pulse Width Modulation ◽

Stable State ◽

Piezoelectric Element ◽

Voltage Source ◽

Vibration Velocity ◽

Constant Voltage ◽

Vibration Displacement ◽

Controlled Switching ◽

The Stability ◽

Piezoelectric Voltage

Two novel piezoelectric damping techniques (VSD and PWMD) are compared in this paper to the traditional resonant shunt damping technique and SSDV technique. In VSD, the switching shunt circuit turns ON or OFF according to the polarity of the vibration velocity of the host structure to shift the piezoelectric voltage phase. An external voltage source is connected to enlarge the voltage amplitude across the piezoelectric element and to optimize the dissipated power. The PWM shunt technique not only can decrease the audible noises more efficiently but also ensure the stability of the control system with a constant voltage source. The theoretical and the experimental results show that the piezoelectric voltage can be adaptive to the vibration displacement by the pulse widths variation, so the PWMD can stay in stable state with a constant voltage source and can still provide a very good performance.

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Automatic Control of Aircraft Engine in Conditions of Stand Test

Mekhatronika Avtomatizatsiya Upravlenie ◽

10.17587/mau.21.86-92 ◽

2020 ◽

Vol 21 (2) ◽

pp. 86-92

Author(s):

G. P. Shibanov

Keyword(s):

Automatic Control ◽

Aircraft Engine ◽

Fixed Time ◽

Transient Processes ◽

Dynamic Mode ◽

Time Interval ◽

Time Of Arrival ◽

Stand Test ◽

Operating Modes ◽

Tolerance Control

The general principles of automatic control of aircraft engines and functionally related systems in the conditions of their stand tests are suggested. These principles are prospectively reduced to six sequentially implemented procedures or steps. In accordance with these principles, the control of aircraft engine parameters is carried out by a computer-aided test equipment (CTE) based on a computer complex that implements algorithms based on Boolean algebra and the algebra of events and states. These algorithms allow control procedures to be carried out in dynamic mode in accordance with the schedule of testing an aircraft engine. With this control, the specified sequence of operating modes of the aircraft engine undergoing testing is observed without fixing them in time and with the possibility of skipping or repeating individual modes. Parameters are monitored at each of the next aircraft engine operating modes only after all parameters are checked in the previous mode and the value of the main determining parameter reaches the value determined for this mode. During the period of transient processes, parameters are controlled only at the points of extremum of the values of the main determining parameter with fixing the time of transient processes and determining that. "In the tolerance" or "not in the tolerance" is the checked parameter and the fixed time interval. Upon arrival of the signals from the monitoring object, the time of occurrence of which is unknown, and only the time interval during which they can appear is known, any of the CTE operation modes are terminated, tolerance control of the parameters provided by the program is performed, and the previously interrupted mode is restored. Simultaneously with the tolerance control of the parameters, the time of arrival of the above signals is recorded. The group of emergency parameters is monitored continuously throughout the entire period of stand test.

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Dynamic Model of Gears with Trapped Oil and Coupled Analysis in External Spur-Gear Pump

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.130-134.610 ◽

2011 ◽

Vol 130-134 ◽

pp. 610-615 ◽

Cited By ~ 2

Author(s):

Yu Long Li ◽

Kun Liu ◽

Fu Chun Sun

Keyword(s):

Dynamic Model ◽

Dynamic Characteristics ◽

Contact Stiffness ◽

Spur Gear ◽

Vibration Characteristics ◽

Coupled Analysis ◽

Vibration Velocity ◽

Gear Pump ◽

Vibration Displacement ◽

The Impact

In order to understand the vibration characteristics of gears based on trapped-oil in external spur-gear pump, from the calculations of trapped-oil pressure and hydraulic load and contact stiffness and trapped-oil stiffness, etc., a dynamic model coupled with trapped-oil pressure was derived for the gears, then an iterative operation based on Runge-Kutta method was used for analyzing the model, therefore the data related to trapped-oil pressure and the vibration displacement and the vibration velocity were obtained in a periodic of trapped oil, and the impact of different backlash value and different distance between two unloading grooves on trapped oil pressure and dynamic characteristics of gears was briefly analyzed. All results of simulation showed that trapped-oil pressure and trapped-oil stiffness had greater impact on vibration characteristics of gears in external spur-gear pump, trapped-oil stiffness could reduce the vibration of the gears; in simulation of trapped-oil pressure, dynamic trapped-oil model related to dynamic characteristics of gears more accurate than the static trapped-oil model irrelated to dynamic characteristics of gears; the trapped-oil pressures in two trapped-oil cavity were different, the vibration characteristics of gears was better that in larger backlash value, etc.. Finally, by the trapped-oil stiffness of the external gear pump is unique, the important conclusions are educed that the vibration of gears in external spur-gear pump is indeed different from conventional gears and so on.

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Development of adequate computational mathematical models of cogeneration steam turbines for solving problems of optimization of operating modes of CHP plants

2016 2nd International Conference on Industrial Engineering, Applications and Manufacturing (ICIEAM) ◽

10.1109/icieam.2016.7911578 ◽

2016 ◽

Cited By ~ 1

Author(s):

N. V. Tatarinova ◽

D. M. Suvorov

Keyword(s):

Mathematical Models ◽

Steam Turbines ◽

Operating Modes

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Information technology for evaluating spline regression parameters when processing data on air pollution in the GIS «AIRNORM»

System technologies ◽

10.34185/1562-9945-4-135-2021-07 ◽

2021 ◽

Vol 4 (135) ◽

pp. 61-72

Author(s):

Anna Polonska

Keyword(s):

Information Technology ◽

Air Pollution ◽

Mathematical Models ◽

Polynomial Regression ◽

Technical Problem ◽

The State ◽

Sharp Change ◽

Residential Areas ◽

Atmospheric Air ◽

Industrial Enterprises

A feature of the tasks associated with the spread of harmful substances in the natural environment is the presence of a large number of parameters that affect the migration of im-purities. Mathematical models of varying complexity are used to describe such processes. The task of air monitoring by industrial enterprises is to collect, process the parameters of atmospheric pollution in the local area and develop, based on the results, conclusions regarding decision-making on the ecological state of both the industrial site and adjacent residential areas. An improved method of data approximation using piecewise polynomial regression is presented. The proposed algorithm makes it possible to increase the adequacy of determining the boundaries with a sharp change in the concentration of a harmful substance, improves the accuracy of the constructed models of the release of a substance into the atmospheric air and more accurately assess the scale of pollution. The developed methods allow visualization of the obtained data to increase the information content in assessing the pollution of a certain area.Along with mathematical models, when assessing the level of pollution, geographic in-formation systems (GIS) are used as a powerful tool that provides: collection, storage, pro-cessing, display of data, analysis, assessment, forecast of the state of the environment of a territorial community. The methods and algorithms described in the article form the basis of information technology and software for solving the scientific and technical problem of visual and analytical analysis of atmospheric air pollution data in the GIS «AirNorm». With the help of this GIS, the results of a computational experiment carried out on the indicators of the level of emission of NH3 for the source V-109 at the State Research and Production Enterprise (GNPP) «Zirkoniy» m. Kamenskoye were obtained and presented.

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SIGNAL PHASE SHIFTS DURING THE MEASUREMENT OF VIBRATION PARAMETERS

Перспективні технології та прилади ◽

10.36910/6775-2313-5352-2020-16-13 ◽

2020 ◽

pp. 100-104

Author(s):

Передерко А.Л., к.т.н.

Keyword(s):

Vibration Signal ◽

Wide Band ◽

Phase Shifts ◽

Vibration Velocity ◽

Measured Signal ◽

Mechanical Shock ◽

Vibration Displacement ◽

Active Vibration ◽

Vibration Parameters ◽

And Control

In systems of vibration control, monitoring, diagnostics, active vibration protection, measurements and control of vibration parameters are necessary. For this, piezoelectric sensors are widely used in them as primary transducers. These sensors, due to their high metrological characteristics, such as accuracy, speed, a wide band of operating frequencies and temperatures, are traditionally used to measure vibration displacement, vibration velocity and vibration acceleration. The use of these types of sensors is necessary due to the need to measure and control vibration at objects with different frequency characteristics. The article considers possible distortions of the measured signal at the output of the sensors due to phase shifts. These phase shifts must be taken into account when developing and constructing measurement and processing schemes of the vibration signal. This is especially true when measuring and recording a rapid vibration processes, such as mechanical shock.

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