Next Meeting

Next meeting will be held at the BC on Saturday,23rd July at Noon. (timings tentative).

Currently planned agends - Puzzle Solving, Anagrams,(you get the idea) & Quizzes. All members encouraged to contribute.

C ya There,

Cheers,

general trivia quiz

Here's a quiz i conducted a week back. take it and mail me the answers. i'll put them up in a few days.



1.Who is now the second largest shareholder in Juventus FC, after Giovanni Agnelli (of Fiat), who has a stake of 63%?

2. "I'd hate to die twice. It's so boring" were his last words. He used to sign his paintings with a pseudonym meaning 'Its done'. A movie 'Infinity' was based on his life. Who?


3.American scholar Clement Moore's 1822 poem, 'A visit from St.Nicholas' gave rise to what popular tradition?


4.For which Olympic event is there no official World Record? Why?


5.The 13th century brothels of Paris were the first to have what, following a royal order that they should use something to demarcate themselves from normal houses?


6.This started as "Fourscore and seven years ago----." What did it end with?
hint- you've heard it a million times.

7.What is a circumorbital hematoma commonly known?


8.In 1791, a Dublin theatre owner James Daly is said to have made a bet that he could introduce a word into the English language within 24 hours. However, this word was originally used to describe an annoying person who tended to snoop into others' affairs. What word?

9.He studied Western Classical Music at Trinity College. He was a member of bands like Magic, Nemesis Avenue etc. Who?

10.This bowler has dismissed 67 batsmen on a zero in his Test match career, which is a record. Who?

10.When his experiments required accurate timekeeping, he invented the pendulum clock. His arguments with the church led to his being placed under house arrest - he got off lightly as others had been subjected to the inquisition for less. Who?

11.He invented a system for canceling used postage stamps. When building a gun that could fire rotating projectiles, he discovered that the barrels were quickly wearing out under the strain. So, what did he invent to solve this problem?

12.This company was originally known as the Gutta Percha company, as they had a monopoly on the production of Gutta Percha insulated wires (that is, insulation made of paper and cardboard) for telegraph cables etc. Now, they are one of the largest players in the teleco and ISP sector (even now they are the monopoly telco in most parts of the Caribbean, for example). Name them.

13. Usually bottled in one of three categories: plata ("silver" – aged no more than a couple of months), reposado ("rested" – aged about a year), and añejo ("aged" – aged from 1 to 3 years), this liquor has been marketed with a worm" Hipopta Agavis"in each bottle.Name the liquor?.

14.A style of documentary-making used in film and television, the name derived from the idea that events are seen candidly, as a fly on a wall might see them and called the "Fly on the wall" techniuqe.How do we know these works better as

15.How do we commonly know a DEL Number? .

16. Which product was first certified by ISI?


17. Which is the only 3-wheeler vehicle (in India) which does not require a license?


18.Shiv Ratan Agarwal, the MD of Shivdeep Industries started of by making a product for soldiers to carry with them for days together. This company now controls a 70% share in the Indian market. Name the company.

19.. Prior to his current assignement, he was a Professor of Technology and societal Transformation. Who?

this sat

we're meeting this saturday at 12. the agenda (tentatively) is as follows-
1. a talk on the stock markets.
2. a talk on biodiesel
3. brainstorming for VJTI's technovanza. that is, seeing what events we can take part in and discussing all that stuff (if at all anybody's interested)

so kindly haul your asses to the boat club at noon.

meeting on saturday

the activity club

We're meeting on saturday afternoon at about 2.00. we plan to discuss the line tracer robot which doesnt seem to be getting beyond the discussion stage. we then plan to head off to PSPL on senapati bapat road for an open quiz at 4.30. be there.

Robotics

LINE FOLLOWING

VEHICLE

Contents

• Introduction


• Differential Turning


• Its implementation


• Transmitter and receiver circuitry


• Working


• How to go about?


• Notes

Introduction

One of the most fundamental functions that any automated vehicle or Robot
must perform is to move along a fixed path without manual control. The
path may be defined in terms of a marking on ground, colour of side-walls,
obstructions in field, or towards a sound or heat source.

A Line following vehicle is designed such that it traces the the path of any
curve which is marked in white colour against a dark background (usually black).
The curve is about 2-3 cm thick and is generally zigzag with sharp turns.

Differential turning

DT is the simplest and hence the most commonly used mechanism for directing a
vehicle. Consider the case when we want our vehicle to take a right-turn. Our
vehicle must rotate about the point of contact of the right wheel and the
ground. This can be achieved by stopping the right motor and hence allowing the
vehicle to rotate about the point of contact with the left motor.

Thus, the vehicle would take a right-turn. Just remember that the motor in
the direction in which we want our vehicle to turn must be switched off while
the opposite motor remains on.

Implementation

DT can be implemented using a very simple logic. Assume that initially the
white line is exactly below the centre of the vehicle. As soon as the white line
curves towards right, our right motor must be switched off, i.e. as soon as the
right wheel is close to white line right motor must be switched off.

We place a sensor sufficiently close to each wheel and a transmitter
equidistant from both sensors.

The transmitter emits Infra-Red radiation which are incident directly
on the surface below. We assume that the black part completely absorbs the IR
radiation while the white part completely reflects it. The sensor on each side
will detect the the type of surface (black or white) exactly below it depending
upon whether IR radiation is incident on it or not.

When the sensor sees white below, it will send a signal to switch the motor
on its side off. If it sees black below it sends a signal to keep the motor
running. Thus, the vehicle will trace out the path formed by the white line.

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Receiver
and transmitter circuitry

The main circuit components used are listed below

R = 1.87 k D = 1N4007

C1 = 1 nF C = 0.01 uF
IC LM555 IC TSOP 1738

M = Motor

Working

The IR LED is connected between terminals 3 and 4. The resistance and
capacitance values are selected such that it operates at a switching frequency
of 38 kHz. Diode D is shunted across R so that the voltage across the IR LED is
in the form of a square wave.

Switching frequency of the IR LED = 1.44/RC = 38.4 kHz

The IC TSOP 1738 gives output HIGH when IR radiation is not incident
on it. This drives the base of the Power Transistor and pushes it into
saturation making current pass through the motor. When IR radiation is incident
on the TSOP (which is reflected from the white line below), its output
goes LOW and drives the power transistor into cut-off. The motor is
switched off and the vehicle turns in the required direction.

How to go about?

While designing the electronics part here is a step-by-step procedure.

• Check the motor specs - Max. Voltage, Max. Current, Speed and Torque


• Finalize the Power Supply method. Check the number of components requiring
  power supply and their respective voltages. Hence design an appropriate
  potential divider.


• Check LED specs. - Max Current, use suitable current limiting resistor.


• Check TSOP specs. - Input voltage etc.


• Modify the circuit as per available components


• Use appropriate power transistor- Check saturation base current, max
  collector current etc.


• Design Physical Layout of the circuit - for example IR LEDs, TSOPs should
  be on the underside while the power transistor must be well exposed.


• Test each component separately and then mount on the circuit.

Notes

1. In differential turning, the vehicle is pivoted about the stopped wheel.
   This makes it necessary that the wheel must stop instantly when its power
   supply is cut off, i.e. the motor must not roll after switching off. Thus,
   choice of motor becomes important. DC motors make a good choice.


2. The TSOP sensor will be placed near each wheel. When the vehicle is
   turning about a wheel, the Sensors will also rotate and eventually the surface
   below them will also change.


3. The sensors must be placed such that they are sufficiently away from each
   other and sufficiently in front-of the wheels.


4. The sensors must not be too high above the surface.


5. The sensors must be capped by a black paper on the side of the IR LED.
   This is to be done because the TSOP must respond only to the reflected
   radiation and not that coming directly from the source.


6. Just imagine what happens when the vehicle turns. The entire vehicle is
   rotated about by a single motor and thus must produce high torque. In case of
   a four-wheeled vehicle the rear-wheels and the rear body require a lot of
   torque to rotate about the front wheel. This will make the vehicle insipid.
   Moreover the rear wheels roll over might change the direction of the the
   vehicle and make it lose the white line.


7. A two wheeler is a safer choice because of its low torque requirements and
   low weight. The design needs to be precise, however.

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