CAREER EPISODE 2
INTRODUCTION:
Time frame of Project
:
Educational Institution:
Location
: India
Designation
: Student, Team Member
CE 2.1
This episode talks about the 'mini'-project I worked on during the final year of my
undergraduate course. The project was about scanning the interior of premises remotely via a
robotic sensor for threat assessment. The title , as submitted in the report, is 'Virtual Blue
Printing Robot for Indoor Surveillance in Combating Urban Terrorism'. It spanned from
December 2011 to April 2012 at which time I had finished the full design and had also made a
prototype. This project was done in Chennai, Tamil Nadu, and India under the supervision of
my professors in college. As a Student, interested in embedded systems and having successfully
completed a project in the field of computer vision the previous semester, I was fairly confident
approaching this new problem.
CE 2.2 BACKGROUND
CE 2.2.1
I undertook this project with the intent to further my understanding of embedded systems from
just textbook to practical use. Urban threats of terrorism is a very real issue and this project
aimed at making the fight safer for the military and Police. In addition to technology that
existed at the time, the integration of different sensors onto one platform was step in a new
direction. The ideas I had were put into practice by me and a couple of my colleagues under
the guidance of my Professors. The project was done in three phases. The design phase was the
first and all ideas were shared and a working plan was settled upon. The next was the modelling
and prototyping. Finally a full report was submitted at the end of the project.
CE 2.2.2
I had previously worked on an analytical project. The experience gained from which helped
me have a better design and implementation view point while designing this project. The Idea
I had was to create a remote sensing probe which could work in closed urban environments. I
designed the probe with two broad capabilities. The predominant of which was to map the
internal structure of the premises using a interruption counter based odometer for calculating
the distance covered in any direction. The secondary feature was integrating different threat
sensors such as gas sensors and high temperature sensors on the platform. A final conceptual
idea was to also have an integrated weapon system on the probe. This was not realised in the
project due to the dangerous nature of the undertaking.
CE 2.2.3
In a hostile environment where there are many corners and long restricted corridors are present,
it is dangerous and sometimes impossible for a human being to scour the whole region. Using
this semi autonomous Robotic system, it is possible to gauge threats from a safe distance. I
designed the robot to make use of a distance measuring sensor which when working in tandem
with a motor, can virtually construct a blueprint of the paths and also establish where hostiles
are. This can be a gas leak to terrorists. With this in mind I designed the robot to be small,
easily hidden package. The prototype was, however, designed to test the sensing capabilities
and not the stealth.
CE 2.2.4
During the course of the Project I had to organise work between myself and two of my fellow
students. As I had already worked with one of the students, I could further my team managing
and leadership capacities. Creating a working prototype required that I learn to program a
microcontroller. Having worked on embedded systems earlier in college lab courses, I was able
to borrow good experiences and practices. In every step, we created proper documentation and
records of all the ideas we had. At the end of the project, we submitted a full technical report
to the faculty of the College. During the course of the project, I sought guidance from my
teachers which helped me identify problems before they occurred and hence the work
progressed smoothly.
CE 2.2.5
Organisation Chart:
Suman Mishra,
Head of the Department
N Madhu Manoharan,
Faculty Advisor
Varsha Tripathi,
Akash,
Elizabeth Minu Joseph,
Jelin,
Student
Student
Student
Student
2.3 PERSONAL ENGINEERING ACTIVITY
CE 2.3.1
During the designing phase, I made a survey of literature that was available on existing
technology and zeroed in on which could be used to realise my ideas. It was diligently done so
as to give citations and credits where they were due. The ideas put into this episode were a
result of informed discussions with my colleagues. Working as a team enabled the delegation
of work amongst ourselves. I took the managerial role and organised the work to be done the
stipulated timeframe. After the literature was surveyed and information gathered, I proceeded
to the design phase.
CE 2.3.2
The robot was designed to be a wireless device controlled remotely using a laptop-type device.
Both the probe and the controller had a transceiver each working using the ZigBee protocols
for duplex communication. This was chosen because it met the IEEE standards and hence was
easily implementable. The idea being, real time control whilst assessing the threats. Apart from
the proposed mapping system, there was a camera for visual feedback and hence enabling
control directly. Next I did a market survey to find out what were the existing technology when
it came to temperature and gas sensing.
CE 2.3.3
The gas sensor I selected for use was MQ-5. This is combustible gas sensor. It is a relatively
small and compact system with no movie parts. I decided that this would be an ideal choice for
the gas sensor and was used in the sensing platform. It had a fast response and worked for gases
like LPG, methane, etc., while also being mildly sensitive to alcohol making this a versatile
device. For temperature sensing, I used the LM35 sensor. It had a working range between -55o
C to 150o C and at worst, an accuracy of ± (3/4)oC. The sensors come in a hermetic transistor
package and can be integrated onto the circuit board with ease. For visual feedback a commonly
available IP closed circuit camera was used. The H21A1, H21A2 and H21A3 consist of a
gallium arsenide infrared emitting diode coupled with a silicon phototransistor in a plastic
housing and this was used as the opto-isolator. The XBee transmitter and receiver package was
used to facilitate wireless communication. This worked with existing IEEE standards and made
integration and remote controlling of the probe possible. It had good reliability when it came
to information transmission. All these components were interfaced with a PIC microcontroller
(Peripheral Interface Controller). The model used had 40 pins with 5 ports which were used as
the link between the sensors and the controller. Specifically the PIC16F877A was used in this
project. It was a widely used system and hence documentation was readily available. The mix
of good features such a high clock-speed (20 MHz), sleep mode, a good size programmable
memory and number of ports helped cement this particular device as the choice for the
microcontroller.
CE 2.3.4
After deciding on the components, the integration of all those into a single working unit was
the challenge. Having not worked previously on such a challenge, I found myself learning and
gaining valuable experience tackling this task. It helped that the components were carefully
selected so that they could be interfaced with the main controller without much difficulty. A
good compromise was reached between absolute specifications and integratability. Next step
was to design and create a working prototype. The sensors used were all voltage based, ie., a
change in their output voltage would correlate directly to the quantity they measured. A circuit
was designed to read the raw output data from the sensors and this was processed with the help
of the calibration data provided by the manufacturer. Hence, individually all the sensors could
work on a single circuit board. This made the device ideally portable and this enabled integration
onto the robot convenient. Before the sensor components were permanently soldered onto the
board, testing was done on the data processing system to ensure that they worked as required.
This was done in two steps. A virtual simulation was performed to check the logic and
mathemathics behind the coding on the computer. Then a sample voltage was supplied to the
various input points simulating the signal from each sensor. This test was done to check if there
were any problems physically on the circuit. Once this was succefully completed the actual
sensors were connected. Then there was a final round of testing to ensure that everything worked
together. This was also successful. The remote control module for the robot and the sensor where
first mounted on different circuit boards to for the sake of modularity and easy access and trouble
shooting. The idea was to later integrate both onto a single board. Since the components chosen
were specifically done so to ensure compatibility, there were very few, and rather insignificant
problems when it came to putting all the components together. From this point forward, the
prototype had to be tested in a real world, controlled, situation.
CE 2.3.5
In the prototype testing, I used a simplified version of the robot. This one was designed to
follow existing RFID tracks while transmitting data back to the receiver module. The sensors
were mounted on a frame which had motorised wheels. The steering was controlled by the PIC
microcontroller. This enabled the movement of the robot with minimal human intervention.
The temperature sensor, gas sensor and the opto-isolator were all interfaced with the
microcontroller. The ZigBee transceiver module, also controlled by the PIC, provided the
wireless interface necessary for communication with the user. All the components were
mounted rigidly on the mobile frame. The sensors were upfront and the controller was near the
middle trying to keep them from interfering with each other's signal. The whole device was
controlled and feedback was received by a virtual control panel I designed in Lab View. This
was the most efficient method test the prototype. It was tested to detect small gas leaks and
temperature changes, both tests being successful. Once the project was completed, I, along with
my colleagues, made a formal presentation in front of my Head of the Department and the Faculty
Advisor. They were tasked with assessing the quality of the work and to give any suggestions that
they felt were necessary. One of the suggestions was to incorporate a manual control system for
the robot in addition to the automation system for more robust control. This was considered but
was, at the moment, out of the scope of the project. The overall reception of the work was positive.
In addition to this, a comprehensive report was submitted to the College. The comprehensive
report was considered for grading. It included all the component information, ideas and the
description of the entire process from conception to the final prototyping. All of the reporting was
done on schedule and without incident, thus successfully completing the project.
2.4 SUMMARY
CE 2.4.1
This undertaking helped me improve my knowledge on embedded systems which is a field I
am interested in. This episode was driven by the want to improve the livelihood of the people
who risk their lives for their fellow human beings. It also provided a good starting point in
prototyping. Creating a prototype was a different challenge than I was used to at the time and
hence I was able to learn everything from people skills to microcontroller coding. There were
meetings held with our teachers and also peer presentations where I was able to assess the
works progress. Most of the meetings were devoted to solving small problems which would
come up during the course of the work. Having regular such meetings helped me set short term
goals and work towards reaching them. Overall, I played the part of a managerial head amongst
my peers in the project. In addition to this role, I saw the implementation of my idea for the
robot, I learnt and implemented the use of software like Lab View and also contributed in the
coding and prototyping of the microprocessor and the probe respectively. As an aspiring
Engineer, I was able to amass a wealth of good experience and knowledge which proved very
useful in the future.
OTHER REPORTS:
CDR Samples for electronics and electrical engineer PDF by Andrew Robert - Issuu