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Namaste, this is a short video in which I would like to share with you the greatest
achievement of my life so far. I am going to do a screen share and present a few slides
to you. Hope you would know something new about me that you didn’t know! So let me
start…You see the photo of the Underground Metro Train and the project was called Microtrac.
Microtrac was a turnkey project undertaken by NG Electric Factory.
This was to provide Underground Metro Train for Calcutta India. This project used a Programmable
Logic Controller or PLC to control the train. The PLC would accept commands from the train
driver and control the traction motors. So what’s the big deal you ask? This was a
very exciting project as it was the first Underground Train project for India. Most
importantly all the lives of the passengers of the train were in the hands of the programme
running on the PLC. An Electromechanical System that was used to accept drivers commands and
control the train was being made obsolete by the anufacturer and hence a replacement
was urgently needed.What were the challenges we had? Traction Principles and how the Metro
Train works had to be understood first - so as to be able to intelligently answer the
questions the customer may raise about our product. It was required to develop a Diagnostic
System which can prove to the Metro officials that our Microtrac behaves exactly as required.
It was required to source all the hardware and software for the Diagnostic System and
write all the software for the Diagnostic System. Lot of data had to be acquired. 48
digital channels which had On or Off status of various switches and 8 analogue channels
had to be acquired. These were Voltages applied to motors, current drawn by them, speed of
the train etc All the data had to be stored on the hard
disk at the rate of once every 15 milliseconds. This was a very tough requirement as the available
technology at that time was predominantly Intel’s 8086 processor based computers.
All of this was to be done while the train moved at 60 kmph under the control of Microtrac.
And show live data in graphical way. The computer had to not only acquire data at a very high
rate – but it also had to display graphs and charts with the live data at the same
time while the hardware is already under stress due to moving train. The Metro train had a
very tough operating cycle.The train had to start moving; reach a peak speed of 60 kmph
and then smoothly decelerate and come to a perfect stop at the next station which is
only 1km away.The braking involved regenerative braking where energy was put back onto the
power grid.I lead a team which designed and implemented a diagnostic system after procuring
the necessary hardware and software.I wrote all the software components and helped the
hardware team to develop the necessary hardware interfaces. Another member wrote the PLC program
and I was often called upon to solve some logical problems and suggest suitable alternative
approaches to arrive at solution. In this photo you can see my Manager capturing some
live data on a slowly moving train using the Diagnostic System I created. Notice the charts
being shown on the monitor. The software was designed to show them in colour but a colour
monitor was too bulky and delicate for use on a moving train. LCD Monitors were yet to
be invented you see! The Blue box under the table is a Constant Voltage Transformer which
was stabilising the power coming from the generators on board the train.
As these generators were designed for simple lighting, voltage and frequency regulation
was not really a design criteria so we had to protect the computer from unstable power
supply that had lots of surges and spikes. The software was written using Borland C++
and Assembly Language. Data Acquisition cards on ISA bus were used to acquire data from
the traction motors and other hardware on board the running train at real time.
Interface device was designed to convert signals that were at 750 V DC level to those acceptable
by the PC. This is one of the photos we were allowed to take on the train showing the internal
control systems. You can actually see only my right hand operating the computer keyboard
while with my left hand I had to prevent the Programmable Logic Contoller unit from swinging
wildly. This unit had to be mounted on a hinge as the interface cables were coming from the
back of the unit and the whole unit would swing wildly if not held by hand. There were
cables and interfaces which would have provided some support but we did not want to risk it.
You can see my colleague holding the monitor down in place as it would have lurched out
of the table when the train moved and went through the tough duty cycle. You can also
notice the sceptical expression on the face of one of the railway officials – who wasn’t
really happy about our taking a photo nor was he initially confident about our test!
He was half expecting the whole thing to fail! Here you can see the faces of the railway
officials and myself showing the diagnostic to them. As you can see the formerly sceptical
railway official has now turned around and is watching with interest. The person sitting
next to me is the person who was in charge of the whole project and he was the one who
signed the purchase order and the cheque soon after this demo.
It was a cheque for 60 Million Indian Rupees! He was so happy and confident with our demonstration
that he said that he is putting this same train on active service at 5 pm during peak
time the next day and he asked two of us to be in the driver’s cabin just to make sure
everything went well! He had already signed the cheque and handed it to us – so we were
not that concerned about the purchase order itself – but we were naturally scared because
we were the ones who wrote the software and designed the hardware and we had no way of
imagining what could go wrong when thousands of people piled into the train at peak time.
Thrilled and scared at the same time! But the live service went very well indeed
and I am here to tell you about the whole project. This has been the greatest achievement
of my life so far – because of the challenges we faced and what we achieved. The cheque
that we received for the company was enough to pay the salary for over six thousand employees
for one month. I am certainly proud of this achievement.Wouldn’t you be?
Thank you for listening to me. Hope you know something about me now!