Our group name: "DeGrebots"

Etherpad

In Etherpad we will be posting our thoughts and Ideas about our project.

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Robotic Ideas:

• A robot that might be dancing greek dances. Like Syrtaki or other tranditional dances.

• An olive pressing machine that will be representing the oil production.

• A robot that will be cooking

A Robot that will giving a performance of Karagiozis! Very unique Idea.

This is Karagiozis (a short example performance)

and this is another example performance about saving the environment by the group EcoFans club of the Hellenic American Union

https://www.youtube.com/watch?v=VB_jn0WkG1Y

it is a VERY GOOD idea! Greeks love Karagiozis and it is very tranditional! 

This is what our robot must do: https://www.youtube.com/watch?v=gH48YiCoAkE

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Robotic Ideas:

• A robot that can build something out of lego (the flag of Greece or Germany)

• Or a robot that can dance something traditional (as you already mentioned)

We have to do a video chat

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I ´ve already asked you through Instagram. In my opinion the Karagiozis Robot is the most unique one because it is a unique idea. Nobody has made that kind of a robot before.

I have also sent you a mail with my contact media

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Shadow Puppet Mechanism

History

Shadow puppet theatre likely originated in Central Asia-China or in India in the 1st millennium BC.

Shadow play, also known as shadow puppetry, is an ancient form of storytelling and entertainment which uses flat articulated cut-out figures (shadow puppets) which are held between a source of light and a translucent screen. The cut-out shapes of the puppets sometimes include translucent color or other types of detailing. Various effects can be achieved by moving both the puppets and the light source. A talented puppeteer can make the figures appear to walk, dance, fight and laugh.

Shadow play is popular in various cultures, among both children and adults in many countries around the world. Shadow play is an old tradition and it has a long history in Southeast Asia, especially in Indonesia, Malaysia, Thailand and Cambodia. It has been an ancient art and a living folk tradition in China, India, Iran and Nepal. It is also known in Egypt, Turkey, Syria, Greece, Germany, France and the United States.

The two main characters in the Greek version of this puppet theatre is Karagiozis (a poor peasant Greek) and Hatziavatis (the more educated who works for the Ottoman state, or simply law and order). Karagiozis uses his "native wit" and always outdoes Hatziavatis' superior education. This is also very similar in the Turkish version called Karagöz.

(source Wikipedia)
 

Design

Here are the photos of the mechanism we built for moving the puppets.

For moving the figures left & right we use 2 EV3 medium type servo motors.

For our mechanism to get a maximum mechanical advantage, which is described as the ratio of output force to input force applied to a mechanism, we used a small gear that is driving a big gear. In this way the speed reduces but the torque increases so that we don't overwhelm our motors. 

The movement of the figures is controlled by 2 EV3 touch sensors (each puppet moves independently).

There is a latch at the end-point of each moving arm, so that the puppeteer can easily withdraw the old one and fix on a different new puppet.

Here is the mechanism with the puppets loaded: Karagiozis and Alexander the Great.

Video

Here is a video showing our mechanism in operation. We now need a scenario and a white bedsheet to be used as a screen for a play!

Programming

Initially the mechanism must start its operation from a well known position, say puppets fully retracted. The following piece of code (Software Lego EV3 Classroom) does this for the first puppet (similarly for the other one). Motor is connected to the A port and it moves at the fully end position when its speed drops from the initial 30% to below 25% marking that it hit its end boundary.

After this the main program inside a forever loop waits for the puppeteer to press the Touch sensor at port 1 and then the motor extends the arm for 220 degrees.

When the Touch sensor button is released, the motor retracts to its initial position.

Here is our EV3 Education Classroom code for it: ShadowPuppets code