Lucy's hand

Let's Make Robots Robots
1

UPDATE - 8. sept. 2010 - first h-bridge and controller board done.---

This is part of my biggest robot project ... It has enough degrees of freedom (5+gripper), enough speed and strength. Made out of electric window motors (ultracheap, 12V, fast enough, geared and powerful), aluminium and servos for wrist. So far I have built the mechanics and built H-bridge.

Because it has no electronics it moves only when I connect it to battery. And it moves fast, and silent like a ninja, and, apparently strong enough to hurt me when bumping in my head. 

schematic
schematic800×446

The Idea:

Ulitmate goal is - big and awsome robot hand, controlled by atmega, what is connected to PC. On top of this hand there is a camera and laser for computer vision. And all of this is powered from PCs power supply or car battery.

hand!!one
hand!!one1024×768

 

 

H-Bridge board:

Hbridge board has attiny13 for control, serial input, adc input for potentiometer (do know on what angle the joints are), programming header, TLE5206 5A H-bridges, red led connected to error_flag pin (should show when there is short circuit), and couple of capacitors. 5206's datasheet said that it has protection diodes and other stuff like that so I believed it..

schematic2

ToDo:

  • Order Attinys
  • Make hbridge boards (One done)
  • Test hbridges with car battery. (One tested)
  • Program hbridge board..
  • Make gripper
  • Test some more
  • Make Atmega controller board. (Design is done, first prototype is done)
  • Test even more
  • Make and use USB-to-TTL module (Built but not programmed jet.)
  • And even more testing
  • Acquire a webcam and laser pointer
  • Program like a weasel
  • Test
  • Hook everything up with my extra pc
  • Install OS to PC
  •  
  • Profit...

wrist
wrist1024×768

Materjals and cost:

 

  • 2x servo from ebay - $10
  • 3x electric window motors from scrapjard - $15
  • bunch of aluminum from scrapjard - $1
  • piece of wood - nothing
  • endless amount of bolts and nuts - $5
  • 3x TLE5206 5A H-bridges - $13.50
  • Old PC from whereever - free
  • 10x Attiny13 - $10

Is violent and useless

  • Actuators / output devices: 2x Servo, 3x electric window motors
  • Target environment: My workbench, everywhere(if on moving platform)
This is a companion discussion topic for the original entry at https://community.robotshop.com/robots/show/lucys-hand
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Video

Can you take a video in order to see it in action?

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Unfortunately not yet. It

Unfortunately not yet. It takes about week or so to make h-bridges and gripper. There is no cool moves to show yet.

4

Looks interesting! A video

Looks interesting! A video would be great. :slight_smile:

Can you tell something about the position control of the window motors ? What for a controller you are using? (PID or something?) Which sensors do you use for position feedback?

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I plan to

I plan to use potentiometers for position feedback. The output from there will go to analog input of the hbridge board.

 

And yes, idea was to use something like PID. The bigger the error between the required angle and the real angle the faster the movement.

6

Great idea my friend. Are

Great idea my friend. Are there specific types or car brand for choosing good power windows motors? I know that there are different shapes etc… The scrapyard is the best to find good stuff. Thanks and keep up the good work and show us more too.

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I think these are from Audi.

I think these are from Audi. But it depends on the use, smaller cars have smaller motors… And you should always choose motors that uses cable transmission (or whatever is it in English). These are very easy to modify and they are continuous rotation. First one I bought used just pieces of metal and had about 70 degrees of freedom. It was made from hard steel, hard to use and mount.

 

8

Hi! Ok thanks I will check

Hi!  Ok thanks I will check this out,it gives me a good hint.