4. REAL TIME OPERATING
SYSTEMS
A Real Time Operating System are
intended for real-time applications.
A key characteristic of RTOS is the level
of its consistency concerning the
amount of time it takes to accept and
complete an application´s task.
5. Real Time Computing
In Computer Science, Real-time
computing or Reactive computing is the
study of hardware and software systems
that are subject to a ´real-time
constraint´.
A Real-time system is the system where
its application can be considered to be
mission critical.
So, a real-time deadline must be
met, regardless of its system load.
7. AIR TRAFFIC CONTROL
Air traffic control (ATC) is a service
provided by ground-based controllers
who direct aircraft on the ground and in
the air.
The primary purpose of ATC systems
worldwide is to separate aircraft to
prevent collisions, to organize and
expedite the flow of traffic, and to
provide information and other support
for pilots when able.
8. Modes of Air Traffic Control
There are two types of controls that are
exercised by the Air Traffic Control
Systems :
1. Air Control
2. Ground Control
9. 1. Air Control :
The primary method of controlling the
immediate airport environment is visual
observation from the Airport Traffic
Control Tower (ATCT)
The ATCT is a tall, windowed structure
located on the airport grounds.
Generally planes in air are having more
priority than on ground due to hazards.
10. 2. Ground Control
Ground Control is responsible for the
airport "movement" areas, as well as
areas not released to the airlines or
other users.
Ground Control is vital to the smooth
operation of the airport, because this
position impacts the sequencing of
departure aircraft, affecting the safety
and efficiency of the airport's operation.
12. Usage of V-Model in our Project
:
Our whole project is based on the V-Model
process model as we begin with the
exploration of the Requirement Analysis
followed by our proposed Architectural
design which is then followed by the
Technical Blueprint of our design to be
implemented.
After the analysis part is finished, the
designing part commences wherein the
coding part is divided into several units and
the coding is carried out for these units.
13. Usage of V-Model in our Project
:
After the coding part is done over
with, the testing part begins and we test
and debug the code for each unit, .i.e.
the Unit Testing takes place and after
each unit is successfully tested and
maintained.
The System Integration then takes place
wherein we integrate all the units and
then test the system as a whole.
14. Usage of V-Model in our Project
:
This process of System testing and
maintaining is carried out several times
and after getting rid of every possible
loophole and implementing the ideas
successfully, the project is affirmative
with respect to the implementation of the
V- Process Model.
15. Plan of Action for the first
project report :
Gathering required information
regarding project, e.g. runways
information , flight`s speed, height,
distance information.
Analyzing the practical result against the
desired result with time as a constraint.
Selecting the platform for the
development of project. E.g. java or .net
or C , C++ etc.
16. Plan of action during the
second project report :
Runways :
One of the most important aspect of the
project was the selection of the most
appropriate runway and these are the
types which were at my disposal :
1. Asterisk Runway : Handling of planes
was possible from every possible direction.
2. Plus Runway : Handling of planes is
possible from 4 directions.
3. Horizontal-T Runway : Quick arrivals and
departures become easy.
17. Eventual Result (Project
Report 2) :
The type of runway that we opted for
resembled much to the “HORIZONTAL T-
RUNWAY” but not exact.
The reason being that the first two are
more appropriate for scenarios where there
are many number of planes in operation
and also all the directions are available.
But due to time constraints, we had to limit
our project and with limited operations the
runway resembling the „T‟ was much more
suited to our purpose.
18. Plan of Action for Third
Project Report :
The task that we had to accomplish was the most
important aspect in quest of taking the first big step
towards implementation of the ideas wherein we had
to do the designing of the technical blueprint of the
project.
We gathered all the details and information and by
selecting the most important points represented
them on paper using which as a source, a graphical
representation was designed in a GUI (Graphical
User Interface ) environment which in our case was
the Net Beans on Java so as to get the first real
picture of the project .
19. Plan of Action for Fourth
Project Report :
This time we needed to construct the
scheduler for the project. In the previous
project reports we had discussed the
scenarios involving 8 planes ,6 planes
as well as 4 planes.
20. Eventual Result (Project
Report 4) :
As the number of planes were increasing the
scenarios with it also increased exponentially
and as there was always the time constraint as
a significant matter, we had to select the
number of planes using which we could
demonstrate our project successfully.
Finally after going through all the pros and
cons and also considering the fact that the
probability of errors creeping in would increase
with the increase in the scenario, we finalized
the number of planes that would be handled
as 4 wherein 2 two planes would be on the
ground and 2 in the air.
21. Plan of Action for Project
Report 5 :
the coding part was initiated during these
weeks where the time constraint was kept
in mind. The coding part was divided into
different units and code was written for
each unit and then tested with respect to
the actual project.
What was also worked upon was the
controlling of the landing and takeoff of the
planes from the specified directions so as
to divert the planes in case of delayed
landing or takeoff and if the runway is busy.
22. Eventual Result ( Project
Report 5) :
The design of the movement of planes was
done using the JDK Net Beans 6.8 wherein
we used the AWT components like the
JPanel and JFrame and methods like
FillOval, DrawLine,etc as a transmitter in
the project.
Also the “Screen Display” was designed
using the same methodoligies and tools as
mentioned above wherein the input values
could be given and the result would be
displayed depending on those values.
23. Compliance of our ATC
Project with RTS with
Diagram and Descriptions :
24. Notations :
Gamma (Ґ) = Set of Tasks.
T.T = combines the event(E) with task gamma (Ґ), then task is
activated and put into que(Q).
Q = set of all tasks which should be processed at a certain point
of time.
Sched = gets as input the set of ‘Q’(the tasks in Q), then
‘sched’ clears the ordering and puts the task in Q* priority wise.
Pie (π) = Set of rules about priority of tasks.
DM=Deadline Monotonic-Di<Dj ,then π i> π j, i.e. if the deadline
of i is smaller than j,
then the priority of i is greater than j, where D is the relative
deadline and π is the priority.
EDF = Earliest Deadline First.
RR = Resource Rule : If a task is writing in a critical resource, it
can‟t be stopped or interrupted anyhow.
E(events) = the events in our project our when the pilot asks the
controllers.
25. Notations :
For eg-
1)Should I land?
2)Should I take off?
Task = Our prime task in here in this project is to make sure that air traffic is controlled
without any mishappening even in adverse conditions efficiently. The planes that are in
air should be provided runaway as soon as possible according to its deadline and the
plane ready to take off, should be given proper space to take off efficiently.
Then the E(event) is combined with Tasks.
Set of priority rules = The priority rules according to our project are given below :
1) The maximum priority is given to the plane with shortest deadline.
2) Then the planes to be landed are given priority over the planes that have to take off.
3) In case we don‟t consider any plane landing then the priority to the plane from the
planes ready to take off is given according to the given input.
26. Notations :
EDF = Earliest Deadline First : We followed this
criteria and is set in the input window. Input is given
according to the current situation based on already
concluded decision that which plane needs to be landed
first or which can wait for sometime according to the
deadline of the respective plane. So the sequence in the
input window follows the EDF rule of RTS.
RR = Resource Rule : This rule is also being followed
and once the input has been given according to the
deadlines of respective planes and once our scheduler
starts working, i.e. our processes of landing the planes or
take off has started writing in the critical resource, it
shouldn‟t be and can‟t be interrupted anyhow.
In the end when the given task are being completed one
by one, „RESPONSE‟ is being displayed showing the
status of the processes, which are completed.
29. Description :
We begin by proving our authorization as it is a
critical system and then start by giving the inputs
where we enter the number of planes for which we
want to see the result where the limit is a maximum
of 4 planes from where on we specify the number of
planes that are on ground and in air with both the
scenarios having a limit as 2 planes.
Now we specify the direction of either
(North, South, East, West) for each of the planes.
After all the inputs have been given, the execution
part starts where the movement of the plane is
displayed and the highest priority is given to the
plane which has been specified as the first plane.
30. Description :
Similarly the priority is specified for each
plane in the order of which they are
selected.
The Receiver window then pops up and the
current status of the plane is displayed also
with its graphical representation where Y-
axis represent No of planes and X-axis the
time,and we can view the status of the
other planes as well and then by clicking
on Exit, we are logged out of the session.
32. Description :
In our example, we have shown the
worst case scenario that we have
considered in our project, i.e. maximum
4 number of planes (2 in air ready for
landing and 2 on ground waiting for take
off).
They are being set in our input window
and now we have to control their
respective processes.
33. Notations :
L1 = Plane that has to be landed first
from north to south(maximum
priority/shorter deadline).
L2 = Plane that has a bit less priority
than L1 and has to be landed second.
T1 = Plane ready to take off first as
runway is free.
T2 = Plane to take off after landing of
L1.
35. Notation descriptions :
The basic steps that are executed when we handle our
scenario are as follows :
1) L2 was scheduled to land on runway no. 3 (i.e. from
north to south), but L1 was having more priority, i.e. short
deadline, so L1 was given the runway and L2 is being
asked to land from east to west i. e. runway no. 2.
2) L1 lands on runway 3 and L2 moves on the eastern
side.
3) After L1 lands and the runway is clear, T2 plane is
being asked to take off from 3.
4) In the mean time, L2 turns around from 3(north) to land
from 2(i.e. east to west) the plane waiting there T1 takes
off and the runway is clear for L2 to land safely.
So according to the set of priority rules, different tasks
were completed.
36. Hazard Analysis :
A hazard analysis is a process used to
assess risk.
The results of a hazard analysis is the
identification of unacceptable risks and the
selection of means of controlling or
eliminating them.
An analysis or identification of the hazards
which could occur at each step in the
process, and a description and
implementation of the measures to be
taken for their control.
38. Software Specification :
Environment used : Java (JDK
1.6), Java NetBeans Version 6.8.
Operating System : Windows XP
, Vista.
39. Significance of Simulation of
Air Traffic Control Project :
1. This simulation of ATC considers and
satisfies all the 4 directions successfully for the
planes in the air, .i.e. for the planes preparing
to land.
2. This simulation of ATC considers and
satisfies all the 4 positions successfully for the
planes on the ground, .i.e. for the planes
preparing for take-off.
3. This simulation of ATC functions
successfully without any collisions and it
operates in such a way that the chances of
any collision taking place nullifies.
40. Significance of Simulation of
Air Traffic Control Project :
4. This simulation of ATC prioritizes by
using the Earliest Deadline First (EDF)
where in the one with the nearest deadline
is given the highest priority.
5. This simulation of ATC successfully
maintains the exchange of instructions and
signals between the ATC Controller and the
Flight Crew.
6. This simulation of ATC successfully satisfies all
the priorities that have to be considered during the
Landing and Takeoff scenarios.