Grab Every Hilltop

Let me see if I understand how Israel does what it does…..

1. Claim a historical/religious belonging to the land.

2. Buy up whole swaths of land from poor farmers. Settle there, reproduce, buy more land. Repeat.

3. If the locals rise up in opposition, massacre them. Assassinate the internationally recognised mediator trying to resolve the issue. Blow up a hotel while the going is good.

King David Hotel. Blown up by the IRgun in 1946 under the orders of Menachem Begin

King David Hotel. Blown up by the Irgun in 1946 under the orders of Menachem Begin. See 4 below.

4. It doesn’t matter that you ran a terrorist organization, you can still win a Nobel Peace Prize. Yes, thats right, a Nobel Peace Prize!!

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Experimental Robotic Platform : Part 2 – Electronics and Radio Communication

Once the Chassis for my Experimental Robotic Platform was complete, I got to work on the electronics and control sections of the robot. Here are some details about the electronics of my ERP:-

1. Power Supply.

Power Supply

Power Supply.

Power for the 4 high torque DC motors comes from a single 1.3Ah 12 V battery. The second battery (the taller one) is a 4.5 Ah 6V battery that will power the micro-controller unit (an Arduino Mega) and the six servos that control the robotic arm. Once basic testing operations are completed, I will add two more servos for a pan-tilt sensor mechanism (wireless camera/ sonar ranger/ IR sensor etc) that will also draw power from this 6V battery.

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Experimental Robotic Platform Part 1 – Building the Chassis

After successfully completing this superb online course from Stanford University on Machine Learning, I am now quite confident with designing and programming neural networks. Also, playing around with the incredibly powerful openCV library has got me experimenting with computer vision. If I were to try and put these two powerful tools together, and the most obvious outcome would be intelligent, vision capable robots.

But before I get into any of the complex programming needed to create these robots, I first need to build myself a proper ERP, an Experimental Robotic Platform. So this weekend, I spent most of my time working on an ERP chassis……….

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Robot Navigation with a Particle Filter

As robots become smarter, faster and more capable, they are being developed to perform increasingly complex tasks. In order to perform these tasks properly, robots are becoming more and more dependent on accurate navigation through the environment in which they operate. Somewhere in the future, if intelligent robots were to rise up and demand fundamental rights, I think one of the first things they would ask for is the answer to the question, “Where am I?”.

Where am I?

Where am I?

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A Bayesian Solution to the Monty Hall Problem

The Monty Hall problem was created by Steve Selvin and is a classic puzzle whose correct answer is counter-intuitive almost to the point of disbelief. As this page explains, even some of the most competent mathematicians of the 20th century refused to accept the correct answer to the Monty Hall problem for a long time.

Here is the statement of the problem :

Suppose you’re on a game show, and you’re given the choice of three doors: Behind one door is a car; behind the other two doors are goats. You pick a door, and the host, who knows what’s behind the doors, opens another door, revealing a goat. He then says to you, “Do you want to change your selection?” Is it to your advantage to switch your choice?

Monty Hall Problem. Image is from wikipedia

Monty Hall Problem. Image is from wikipedia

What does intuition tell us? After the host opens one door, revealing a goat, we are left with two closed doors, one hiding a car and the other a goat (50% chance of success either way), intuition would lead us to conclude that there is no difference in our chances of success if we switched doors or not.

If only life were that simple………….

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Removing Noise : The Versatile Complementary Filter

After playing around with DC electronics for almost a year now, I thought it was finally time to start mucking about in the world of Alternating Current. To begin, I decided to experiment with the ACS712 Current Sensor.

ACS712 Hall Effect Current Sensor

ACS712 Hall Effect Current Sensor

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Capturing the Elusive Analemma

This image, taken from Visakhapatnam (17 40 N 083 17 E), is possibly the first recording of the Analemma of the Sun ever captured in India. It combines a sequence of 26 individual photographs taken from 24 March 2013 to 13 March 2014. Superimposed over each other, they demonstrate the movements of the sun through the sky over a full calendar year. Click on the image for a larger view.

Analemma of the Sun

Analemma of the Sun

I photographed this sequence using a Nikon D40x camera and a variable ND filter, adjusting filter density, shutter speed and aperture settings at each instance to capture  only the sun’s disc, leaving the rest of the frame completely black. The final image combines all 26 exposures with a background shot I took later.

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Analemma of the Sun

I recently read that to date, Mount Everest has been scaled 1924 times.

Compare this figure to the number of people who have successfully captured the Analemma of the Sun. Any guesses? 1000, maybe 500? Nowhere even close. According to the founder of this website, in the entire history of mankind, not more than 20 people have managed to get it right.

This is the first ever photograph that successfully captured the Analemma. It was taken over a period of one year by Dennis di Cicco in 1978.

First ever recorded Analemma, Dennis di Cicco

First ever recorded Analemma, Dennis di Cicco

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Salvaging Our Inflatable Dinghy

This is our Russian rubber inflatable dinghy that we used during our little camping trip in 2010. Its just the right size for the three of us, has a cute little 2.5 HP outboard motor and is great fun to motor around in. We fashioned that little canopy out of calico cloth and electrical tubing, and while it might look flimsy, it did its job quite well, keeping us out of the blazing sun as we meandered our way through Kumarakom lake and the maze of Kerala’s backwaters.

Better Days

Better Days

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Haptic Controlled Robot Hand

This project brings together the DIY Haptic Control Glove and the Robotic Hand that I made earlier. The cost of this entire project was less than 25 US$. For details on how they were built and how they work, just follow the link for each.

This video demostrates the complete project.

1. Calibration of the glove
2. Control of the fingers
3. Touching finger tips of little and index fingers to demonstrate
thumb movement
4. Performing a simple task
5. Detail of servo movements

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