Технические
науки/9. Авиация и космонавтика
Nickolay Zosimovich, Ph. D. in Aerospace
Engineering
Designing of returning system the small length UAV
Introduction.
Definition of concrete characteristics inexpensive the small length unmanned air vehicle (SLUAV) for operative
study the natural resources and ecological of environmental monitoring, which can make horizontal flight both above water, and
above a terrestrial surface, is the purpose of the given work. The
choice of height essentially depends on features of a relief of a terrestrial
surface and maneuverable properties the unmanned air vehicle (UAV). In this connection it is necessary to estimate opportunities of
performance by maneuver it to change a height of flight at occurrence by an
obstacle. Results of these calculations serve as the initial data for designing a
control system of UAV.
1.
Choice of parachute system domes characteristics of the small length unmanned air vehicle for operative study the natural
resources and ecological of environmental monitoring.
By variety of
the boundary conditions task for a site of braking the SLUAV in cases, when are
possible or 
or 
that specifies
for absence to the design decision with use of parachute system (PS)
with the constant area
of a dome
In this case it is applied two-level PS when for the
second step there are corresponds the area 
calculated under the formula (8.24) [1]: 
and the first
step represents strapped ring cord,
the basic dome which is
characterized by some factor 
subject to additional definition. Its optimum value 
can be received by analogy to the previous formula 
and as 
where
Let's
determine the minimal time delay 
as also other important
characteristic on introduction in action of the basic dome [1]. From a condition of equality of
axial aerodynamic loadings at introduction the first step and the basic dome as
let's find allowable speed of SLUAV at the moment of disclosing the
basic dome:
For
a finding we shall consider a case of braking, when 
и 
Having
integrated the corresponding equation of movement
in limits 
и 
let's
receive
For definition of a real time delay on procedure of division of a dome 
guaranteeing normal functioning of a parachute,
it is necessary to take into account the sum of errors of time of operation of PS separate devices:
where
these errors 
and their number are defined by
design PS and we are considered known [2].
The
parameters chosen according to a resulted technique of SLUAV for operative study the natural resources
and ecological of environmental monitoring a normal
functioning of a parachute at maintenance of a landing set speed 
in all possible range
of a landing corners 
[4-5].
2. Definition of
introduction time in action of parachute system depending on entry conditions
of application the small length unmanned air vehicle for operative study the natural resources and ecological
of environmental monitoring The given problem will consist in definition of
dependence 
in case of
start SLUAV from
a launcher and
dependences 
in
case of dump SLUAV from the airplane
at satisfaction criteria to
conditions [1], we have the following kind in case of dump SLUAV from the airplane by satisfaction criteria conditions and then we have the
following kind 
and 
Let's enter the following assumptions:
1. Let's
accept, that dependence 
can be always shown to next
dependence 
при вычислении кинематических параметров в вершине траектории at calculation of kinematics parameters in top of a SLUAV trajectory.
2. Let's
accept apriori, that time 
practically does not depend from 
at the task of concrete height 
Hence, the problem is reduced to
optimization of dependence 
at value 
providing
some stock from the point of view of braking SLUAV up to preset values of speed
of a landing.
The essence of
a task in view demands the statistical approach to its decision. Really, one of
used criteria (7.13) [1] is circular dispersion of coordinates of a point of a
landing. It in turn, is
connected to influence on SLUAV of some revolting factors, and also with technological
errors of the equipment and onboard devices [5]. Это и предопределяет необходимость статистического подхода к задаче оптимизации зависимости It also predetermines necessity of the statistical approach to a task
of dependence optimization 
However
at definition 
it
is possible does not use a statistical method, being based on the contradiction
and mutually exclusive character criteria
conditions in
[1].
And really,
the precondition for guaranteed performance of a condition 
the earliest introduction in action
PS on a trajectory is used. However at small 
reduction time in the device for a
parachute essentially increases. It is directly connected to increase in
dispersion of coordinates of a landing point that contradicts physical sense of
a condition 
On
the other hand, at increase 
decreases 
due to small time of movement SLUAV in a mode of pancaking. Speed of a
device landing thus sharply grows. The limiting case here corresponds to movement SLUAV without PS when 
however speed of a landing accepts
inadmissible according to a condition (Fig. 1).
The reasons stated above are based creations of the elementary way of
reception of the dependence 
[64] interesting us having a characteristic kind. The ordinate
of a point 
corresponds to minimally probable
speed of a landing when disclosing PS is made in an index point of a trajectory 
The
ordinate of a point 
meets to the greatest possible speed
of a landing at 
where 
time of flight SLUAV up to a point of a landing without
use of a parachute.
Let's execute further the following geometrical construction. In points 
also 
we shall construct tangents to a curve 
which will be crossed in some point
Let's lead a bisector of the formed corner 
which it will be crossed from a curve 
in some point 
In process of removal from a point of 
to the right 
are small changes 
there will meet more and more increasing
speeds 
that creates negative preconditions for
performance of a condition 
At
distance from a point 
to the left 
to small changes of speed 
there will correspond more and more
increasing changes 
that leads to increase in time of pancaking and
consequently, creates preconditions to default of a condition 
The
point 
is on sufficient distance from corresponding
extreme values 
and besides 
, in a vicinity of a point 
smooth mutual change of sizes 
is
observed and 
The
carried out analysis allows to count the value 
found in
such way close
to optimum. Comparison
are results of definition the dependence on
the basis of decision a statistical problem with the offered simplified way,
has shown their high degree of convergence. All this allows avoiding
necessity of a statement a statistical method of optimization and offering the
given simplified way of definition 
as
the basic.
Fig.
1. The way of definition the optimum moment time of
disclosing PS for SLUAV
The conclusion. With
the purpose of definition the concrete characteristics the analysis of maneuvers
was a design of returning system executed of SLUAV for operative study natural resources and ecological of environmental
monitoring.
The literature
1. Грумондз
В.Т., Яковлев Г.А. Алгоритмы аэрогидробаллистического проектирования. – М.:
Изд-во МАИ, 1994. – 304 с.: ил.
2. Генерозов В.Л., Муравьев
Ю.В. Метод наземных стендовых испытаний по вытягиванию парашюта. http://www.mai.ru/
3. Святодух В.К. Динамика
пространственного движения управляемых ракет. – М.: Машиностроение, 1989. – 270
с.
4.
Малкин И.Г. Теория устойчивости движения. – М.: Наука, 1966. – 530
с.
5.
Яковлев Г.А. Об определении граничных значений траекторных параметров
на участке торможения летательного аппарата.// Труды МАИ,
1977. Вып. 424,
с. 38-44.
Таблица регистрации
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ФИО авторов |
Место работы/ учебы |
Телефон / Факс |
e-mail |
Адрес для переписки |
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Украина |
Зосимович Николай
Владимирович |
Национальный
авиационный университет, Киев |
+8 050 170 8017; +80412 41 2049 |
Получатель Зосимович
Н.В. Ул. Схидна, 66, кв. 9, г. Житомир, Украина, 10012 |
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Designing
of returning system the small length UAV |
Технические науки |
Авиация и
космонавтика |
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