Construction - The Body

Intro

The robot is divided into two basic parts, "brain" and "body".
The "brain" is in charge of detecting and analyzing the PS2 video signals.
The "brain" generates play-commands (which tone to press, when to do it and when to strum) for the "body".
The "body" reads the play-commands and controls the fingers movement by them.

Some basic features were required:

• No hacking on the guitar nor the PS2.
• The hand should have a "look-n-feel" of a real human hand.
  (AKA, the fingers should fully move, just "like humans do")
• It have to work fast enough, in order to be able to keep up with the song.
• The "brain" and the "body" should be fully separated.
• All the construction have to be detachable.

Parts (chronologically ordered):

1. Listener

As I said earlier, the "brain" generates the play-commands and sends them via TCP to the "body" listener. The listener translates the play-commands to a proper BYTE sent from the parallel to the body main control board.

2. Control Board

The control board is in charge of the getting the play-commands feed from the computer and delivering them to the fingers engines.


The feeds are getting directly from the parallel port, which generates not more then ~3.5volts. The hands solenoids needs 7VDC and around 800mA to operate. So, current amplifier was needed.

The control board is contains a seven-darlingron-array, where each input pin is connected to one of the data bits on the parallel post (pins 2-7). It's responsible for the current amplifying needed for the solenois which were connected to the darlington's output pins. Our mistake was the we haven't used the right darlington. The solenoids consumed 800mA but the darlington could manage only till 600mA. This caused to burn Refael's parallel port on his laptop….


The lack of time till the first robot live show, I built a new board using the same darlington but instead of connecting straight to the solenoids, I used relay to made the extra current amplifying.

3. Hands

The hand are the most important and complicated part of my job. I needed to build it to as close I can to a real hand (a robotic one). The main barrier was to be able create a real-like finger movement, and still pressing the guitar buttons.

It may look easy when a human holds the guitar, but the buttons are quite hard to press. You need to generate quite a lot of power in order to made them pressed.

The left hand is the "notes-hanler", I needed to make five finger hand.



The right hand is the "strummer", here I only needed one moving finger and four frozens.



The hands were made from aluminum "sculptured" by hand (w/o any use of heavy machinery). Each finger was connected to a solenoid that was hidden inside the palm.

(it's hard to see, but here are 5 solenoids,
connected by wires to the fingers)

Both hands are completely detachable.

4. Doll

We wanted to create the feeling of a full-scale humanoid (human-android) is playing the guitar. First I thought basing it on a skeleton (like the one form the biology labs) will be cool, but I encountered too many mechanical difficulties.

The other option was using a display-window doll. A cool friend (that by incidence is the son of the owner of one of ISRAEL bigger clothing company (Honigman) ) was kind enough to give us a brand new display-window doll free of charge.



The problem with the doll was that his hands weren't in the right position (the elbow's angle wasn't changeable), so I needed to make them a changeable ones…

After cutting the right elbow, I inserted pipes for the control wires going from the control board to the hands and casted whipped polyurethane to make it permanent.

(from topleft->clockwise,
cutting the hand; see the handicapped doll;
pipes and wirings; getting it back together)