Society of Robots - Robot Forum

Electronics => Electronics => Topic started by: aaditya on July 04, 2010, 11:45:23 AM

Title: Best (and relatively cheap) method of controlling a robotic arm wirelessly
Post by: aaditya on July 04, 2010, 11:45:23 AM
Hi, I am currently in my final year pursuing  mech engg. and wish to create a robotic arm with a claw or similar thing which can be controlled using my fingers (kind of like minority report, where tom cruise manipulates the display). It can be wired or wireless.
Title: Re: Best (and relatively cheap) method of controlling a robotic arm wirelessly
Post by: Soeren on July 04, 2010, 01:17:47 PM
Happy tinkering then!

Did you have any questions?
Title: Re: Best (and relatively cheap) method of controlling a robotic arm wirelessly
Post by: aaditya on July 04, 2010, 07:52:04 PM
yes. what sort of sensor,circuit etc should i use? ???
Title: Re: Best (and relatively cheap) method of controlling a robotic arm wirelessly
Post by: Alfa_Zulu on July 04, 2010, 09:32:27 PM
umm dont quote me on this, but i believe you can use servos on the gloves, real small ones and with the signal wire you can calculate the angle the horn is atm
from resistance or something.

i have seen a bipod kit that you could pose it's limbs connected to servo's and it recorded the angles, then you could animate the movements... so this might be the way to go...
Title: Re: Best (and relatively cheap) method of controlling a robotic arm wirelessly
Post by: Soeren on July 05, 2010, 10:29:08 AM
Hi,

yes. what sort of sensor,circuit etc should i use? ???
Isn't that what you have to work out?

Google "Flexistor" and "Power Glove" for starters.
Title: Re: Best (and relatively cheap) method of controlling a robotic arm wirelessly
Post by: Alfa_Zulu on July 06, 2010, 05:11:10 AM
i came up with this idea while driving home this afternoon, it may be kinda stupid but for something simple i can't see why it wouldn't be any good except for being a little bulky.

i have drawn up a rough image in ms paint but basically on sound boards and other similar devices they have variable resistors that are sliders, my plan uses 2 of these for each finger but basically when you clench a fist your fingers pull the mounts with them which pulls the pull/push rod which pulls the VR hence changing the output value.

the push/pull rods should be aloud to pivot also

I'd mount this onto a glove and for simplicity you'll probably only have 2 fingers on your arm so I'd stitch/glue all the fingers together and just use one on the 4 fingers and one on the thumb.

anyway, just a sugestion  :D
Title: Re: Best (and relatively cheap) method of controlling a robotic arm wirelessly
Post by: Selenaut-14 on July 06, 2010, 07:04:33 AM
I'd mount this onto a glove and for simplicity you'll probably only have 2 fingers on your arm...
I'd go with three. One of the most important things I learned to remember in geometry is that you need at least three points to make a plane.
Title: Re: Best (and relatively cheap) method of controlling a robotic arm wirelessly
Post by: Alfa_Zulu on July 07, 2010, 07:42:35 PM
umm yeah but you only really need 2 joints lol, i did have a simpler idea to

this can just use one resistor

this can use just string and it goes from the VR through a tube of some sort over the knuckles (short lengths of straws would do) then it anchors at the finger tip, the VR has a spring on the back of it so it returns to 0 when you straighten your fingers.

then in the code you just make both servos in the finger move a certain amount to make a nice grasping claw.

Title: Re: Best (and relatively cheap) method of controlling a robotic arm wirelessly
Post by: Selenaut-14 on July 07, 2010, 09:54:42 PM
How about pots? You know, like in most servos? Have your pots on your hand transfer the data right over to the arm. It's almost foolproof. You use the same positions between your hand and your robot, and voilĂ : you have q controllable arm. Check every hundredth of a second or so for the positions on your actual arm, and have the corresponding servos on your robotic arm move to the same positions.
Title: Re: Best (and relatively cheap) method of controlling a robotic arm wirelessly
Post by: Alfa_Zulu on July 08, 2010, 10:42:24 AM
these variable resistors i said are essentially pots but slide in a linear motion, how would you connect the pots? lol

any way once i get my mcu working for my 50$ robot i'll use my idea to test it, it would be really sweet  ;D
Title: Re: Best (and relatively cheap) method of controlling a robotic arm wirelessly
Post by: Razor Concepts on July 08, 2010, 11:45:31 AM
Flex sensor. Very simple
http://www.sparkfun.com/commerce/product_info.php?products_id=8606 (http://www.sparkfun.com/commerce/product_info.php?products_id=8606)