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8Распределение массы воды в кусках льда в торосах реки Волга несколько более равномерно (Рисунок 5).
П, %
Рисунок 5 - Распределение льдин в торосах Волги по массе кусков со средним медианным диаметром
Масса воды в кусках льда с медианными диаметрами 60-120 мм, хотя число таких кусков в торосе реки в 1,28 раза больше и составляет 54% от общей массы воды в льдинах тороса. Это в 1,17 раз меньше чем в кусках примерно равной фракции по медианным диаметрам в торосе Байкала. Доля воды в кусках фракции с медианными диаметрами 30-60 мм в торосах на Волге в 1,2 раза больше по сравнению с торосами на Байкале. Доля массы воды в кусках фракций с медианными диаметрами 220-250 мм в торосах реки также выше ~ 1,25 раза.
В соответствии с материальными балансами на снег в торосах в январе приходится 45-49% его массы. Средняя плотность снежной части материала торосов равна 220 кг/м3.
Заключение
1. Высота торосов на озере больше и может достигать 1,8 м.
2. По средней высоте материала в торосах, равной для озера 0,913 м, необходимый диаметр шнековой фрезы должен составлять 1000 мм.
3. Доля кусков льда в торосах, подлежащих измельчению достигает 46% от общего количества.
4. Производительность машины по массе материала, удаляемого с очищаемой трассы должен составлять 700 кг/м3.
СПИСОК ЛИТЕРАТУРЫ:
1. Карташов С.Н. Физико-механические свойства и процессы формирования снежно-фирнового покрова Антарктиды // АН СССР, 1962.
2. А.С. Горшков, В.Ф. Кулепов, А.Л. Малыгин, О.Р. Гусев. Физико-механические свойства наледи, разрушаемой резцом при очистке прибор-дюрной зоны дорожного покрытия [Электронный ресурс] / А.С. Горшков, В.Ф. Кулепов, А.Л. Малыгин, О.Р. Гусев // Современные проблемы науки и образования. - 2014. - № 4. - Режим доступа: http ://www. science-education.ru/118-14134.
3. Кулепов, В.Ф. Разработка и создание ледо-резных машин для технологических комплексов: Диссертация на соискание ученой степени д.т.н. Спец.: 05.05.04 - Дорожные путевые и строительные машины / В.Ф.Кулепов; НГТУ. - Защищена 14.11.2002. - Н.Новгород: НГТУ, 2002. - 602 с.
ON THE CHOICE OF CRITERION FOR OPTIMIZING THE TYPE OF INTERAXLE DRIVE
Efimov A.
PhD, associate professor of chair «Machines and the equipment of an oil and gas complex» at the Don
State Technical University, Russia, Rostov-on-Don
Kireev S.
PhD, professor, chief of chair «Machines and the equipment of an oil and gas complex» at the Don State
Technical University, Russia, Rostov-on-Don
Korchagina M.
PhD, associate professor of chair «Machines and the equipment of an oil and gas complex» at the Don
State Technical University, Russia, Rostov-on-Don
Nikishenko S.
PhD, associate professor of chair «Machines and the equipment of an oil and gas complex» at the Don
State Technical University, Russia, Rostov-on-Don
Abstract
The efficiency is proposed as a single criterion for choosing the type of interaxle drive. Dependence of efficiency on road conditions is shown. On the basis of the proposed approach, the opportunity to select the type of interaxle drive by comparing the quantitative indices, while analyzing the entire range of road conditions, was demonstrated.
Keywords: coefficient of adhesion, disparity coefficient, efficiency, interaxle drive, vehicle
When the wheeled vehicle is moving, there are factors, often simultaneous, presenting conflicting requirements to drive of the driving wheels. First, there is almost always a certain kinematic disparity between the driving axles. In the presence of a kinematic disparity, it is required that, while maintaining a constant drive of the driving wheels, that is, maintaining the distribution of torque in a constant ratio, differential effect to take place, in other words, the wheels should have the ability to rotate at different speeds. In the absence of differential effect, the presence of a kinematic disparity leads to a circulation of parasitic power in the vehicle transmission.
Secondly, there may be different conditions of the adhesion of the wheels. When the adhesion deteriorates, the property of the differential to divide the torque in a certain ratio acquires a negative character. The impossibility, due to the reduction of adhesion, to realize a greater torque by the wheels of one axle causes a reduction in the torque applied to another axle having normal adhesion conditions. This means that the tractive force of not only the low-adhesion axle, but also the normal-adhesion axle, is reduced. In this case, in order to maintain the high tractive and economic qualities of the vehicle, it is necessary to change the former ratio between the torques, that is, their redistribution must take place. In addition to the differential and locked drive, there are a number of self-locking differentials, many of which have spread.
It should be noted a different approach of the authors to assess the expediency of using different types of drive. As pointed out in [1, p. 15], [2, p. 17], there is still no single point of view on creating a scheme of four-wheel drive vehicles transmission, rational from the standpoint of fuel efficiency. In most cases, the choice of the transmission scheme is based only qualitatively or by the results of testing a limited number of cars of one model; numerical criteria for the energy perfection of the transmission, which would make it possible to make an objective comparison, are not yet available.
As an optimizing parameter, a single parameter is needed, which would be decreasing both from increased slippage and from the circulation of parasitic power. It is proposed to choose the efficiency, which reflects the loss for wheel slippage, as an optimization criterion. For machines with two driving axles, this coefficient equals to:
Vs
1
NS1 + NS2
n
(1)
K
where NK - power, supplied to the driving
wheels, NK =; NS1, NS2 - power, lost on slippage, respectively, by the wheels of the front and rear axles.
Nk - power, supplied to the driving axles,
NK = TVTi + T2VT 2,
where Ti, T - tractive forces, respectively, of
the front and rear axles; Vt\ ' VT2 - the circumferential (theoretical) speeds of the front and rear wheels can be expressed through their slippage:
vt 1 = v
Vt 2 = V2
1
1 -s
1 -s.
where V1,V2 - the actual speeds of the front and rear wheels, respectively;
NS1 and Ns2 - the powers, lost on slippage by the first and second axles,
N si = TV si NS2 = T2VS2,
where Vs 1 , Vs2 - the difference between the
circumferential and actual speed of the front and rear wheels respectively,
s,
vsi = Vi
Vs2 = V2
1 -Si
S2
1 -s
Thus, the efficiency of a car with two driving axles
TV + TV s
Vs= 1 -
1 -s 2 2i-s2
1 1 (2) TV-+ TV
1 -s 2 21 -s
2
In [3, p. 120] it is proved that the value of the efficiency is reduced both with an increase in slippage in the case of a differential drive and with an increase in the kinematic disparity between the front and rear wheels in the case of a locked drive. Since the process
1
of overcoming a section with reduced adhesion, as a rule, is of a short duration, and the kinematic disparity between the wheels of the front and rear axles is often not constant in magnitude, then it is necessary to consider the task using methods of dynamics, using a suitable mathematical model, for example, this [4, p.94]. The motion of the vehicle in the time interval from 0 to
T will be considered. The length of the time interval should be selected, proceeding from the fact that after the passage of time T, the process becomes steady. Figure 1 shows a graph of the time dependence of the efficiency of a wheeled vehicle with two different types of interaxle drive: differential and locked.
00000000111111112222
The time, s
Figure 1. Graph of the time dependence of the efficiency of the wheeled vehicle with a differential interaxial drive. Curve 1 - for a vehicle with a differential drive, curve 2 - for a vehicle with a locked drive.
The simulation has been carried out under the following conditions: the vehicle is moved from the place, there is no kinematic disparity, the coefficient of front wheels adhesion is 0.8, and of rear wheels - is initially 0.2, and after overcoming of 1.5 m distance by the vehicle, it becomes 0.8 , which means that the area with reduced adhesion is overcome.
The efficiency g takes a variety of values over
a period of time from 0 to T, therefore under certain road conditions the average value of the efficiency for a period of time from 0 to T can be determined from the expression:
T
nf = \Vsdt.
(3)
0
of adhesion of the slipping axle and the kinematic
disparity, mH , where
mH =
v ' -v v "
100%
To investigate the efficiency in the entire range of road conditions, it is necessary to set a range of road conditions. As coordinates, we choose: the coefficient
' (4)
where V - the speed of the advancing axle, V -
the speed of the lagging axle, V">V
After that, the entire range of road conditions will be divided by a certain step, and the movement of the vehicle will be simulated at each point of the range of CP
road conditions, then '¡S will be calculated for
each point by formula (3) for each point of the range of road conditions.
The results obtained with the help of a mathematical model are presented in Figures 2 and 3.
0,9 0,8 0,7 0,6 0,5 0,4 0,3 0,2 0,1
30,5
17,9 The disparity coefficient, %
0,8 0,72 0,64 0,56 0,48 0,4 0,32 0,24 The coefficient of adhesion
0,16 0,08
ср
Figure 2. Dependence of the mean value of the efficiency
m
on the disparity coefficient mH and the coefficient of adhesion of the slipping axle ф ffor a vehicle with a differential interaxle drive.
0
0
0,9 0,8
0,7
0,6
0,5
0,4
о
<D
ГО
>
§ 0,3 E
0,2
H
0,1
0
0 ,
9,5
30,5
17,9 The disparity coefficients
0,72 0,64 0,56 0,48 0,40 0,32 0,24 The coefficient of adhesion
0,16 0,08
4
0
ср
Figure 3. Dependence of the mean value of the efficiency on the disparity coefficient mH and the
coefficient of adhesion of the slipping axle ф for a vehicle with a locked interaxle drive.
The obtained dependences are analyzed. When the adhesion deteriorates, the efficiency of the wheeled vehicle with the differential drive is reduced by a larger amount, in comparison with the efficiency of the wheeled vehicle equipped with a locked drive. This is due to the greater slippage of the wheels of a vehicle
equipped with a differential drive, compared to a vehicle equipped with a locked drive.
The obtained dependences are analyzed. When the adhesion deteriorates, the efficiency of the wheeled vehicle with the differential drive is reduced by a larger amount, in comparison with the efficiency of the
wheeled vehicle equipped with a locked drive. This is due to the greater slippage of the wheels of a vehicle equipped with a differential drive, compared to a vehicle equipped with a locked drive.
With good adhesion and the presence of a kinematic disparity, the efficiency of a wheeled vehicle equipped with a locked drive has lower values, compared to the efficiency of a vehicle equipped with a differential drive.
If there is a kinematic disparity with a simultaneous deterioration in the adhesion, the efficiency the wheeled vehicle equipped with a locked interaxle drive is further reduced compared to the movement of the vehicle under the same conditions, but without a kinematic disparity. With a complete loss of adhesion by the wheels of one of the axles, a vehicle equipped with a differential interaxial drive can't get off the place, so the efficiency in this case equals to 0.
Conclusions:
1. The obtained dependences correspond to the known data on the properties of the differential and
locked drive, what confirms the correctness of the chosen approach.
2. The offered criterion allows to carry out a choice of type of the interaxial drive on the basis of quantitative comparison of indicators.
REFERENCES:
1. Smirnov G.A., Kupreyanov A.A., Guchkov D.K. About a choice of rational schemes of system "transmission - driving machine" of all-wheel drive cars. "Automobile industry". - 1984.- No. 5.- P. 15-17.
2. Barykin A.Y. Self-locking differential: the probability and ways of using the adhesion of wheels with the road. "Automobile industry "- 2004.- No. 9.-P. 17-21.
3. Andreev A.F., Vantsevich V.V., Lefarov A.Kh. Differentials of wheel vehicles. - M.: Machine building, 1986. - 176 p.
4. Efimov A.V., Kireev S.O., Korchagina M.V. A mathematical model for estimating the type of in-teraxle drive. Problems of machine building and machine reliability. - 2018. - No. 1. - P. 94-100.
NEURAL NETWORK COMPRESSING OF VIDEO IMAGES
Zaitsev S.S.
Student
Moscow Aviation Institute (National Research University) НЕЙРОСЕТЕВОЕ СЖАТИЕ ВИДЕОИЗОБРАЖЕНИЙ
Зайцев С.С.
Студент
ФГБОУ ВО Московский авиационный институт (национальный исследовательский университет),
Москва
Abstract
The article covers the issues of neural network image processing. The possibility of image compression with the help of neural networks is considered.
Аннотация
В статье освещаются вопросы нейросетевой обработки изображений. Рассматривается возможность компрессии изображений при помощи нейронных сетей.
Keywords: neural network, PSNR, discrete cosine transformation, Kohonen network, Karunen-Loew transformation, image compression.
Ключевые слова: нейронная сеть, PSNR, дискретное косинус преобразование, сеть Кохонена, преобразование Карунена-Лоэва, сжатие изображений.
Хорошо известно, что изображения, вследствие своей двухмерности и многоспектральности, занимают очень большой объём памяти и их компактное хранение (архивация) представляет серьёзную проблему. В связи с этим актуальной научно -технической проблемой является разработка и создание средств для компрессии и декомпрессии видеоданных.
Проблема сжатия изображений и видеопоследовательностей актуальна также при создании центров хранения, архивов и каталогов (баз данных) изображений и видеопоследовательностей в цифровом виде (медицинские изображения, космиче-
ские изображения, получаемые при помощи датчиков дистанционного зондирования, фотоизображения и др.). Решение этой проблемы позволит уменьшить объем информации, хранимой на носителях.
Задачу сжатия изображения можно представить следующим образом. Цифровое изображение представляет из себя двумерный массив данных размером. Если за М обозначить количество строк, а за N - количество столбцов, то можно компактно записать полное цифровое изображение в виде матрицы:
