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Topic: ArduDelta - delta Robot implementation (Read 17 times) previous topic - next topic

body28

Jul 03, 2011, 01:30 pm Last Edit: Jul 03, 2011, 03:00 pm by body28 Reason: 1
Hello everyone.
I have just finished my latest project, the biggest I've done so far and now i want to share (brag about).  XD
So... I am talking about my own delta robot. For those who don't know what a delta is, i will briefly explain:
it's a parallel robot (because the lower arms use parallelograms to maintain the lower platform parallel to the
upper platform) very fast, very precise (the concept is, mine is not that good) and a bit complicated
(mathematically speaking) at first site.
I have so many things to say about this project, it took me 7 months to complete (working from time to time).

Components (i have attached a picture with the (almost) final rig).
- 3 black arms for support - made of wood, painted
- an upper platform (the light-brown thing from the top) - made of wood
- 3 standard servos (towerPro 946r) places on their sides (pivot point facing exterior) mounted 120 degrees apart.
- upper arms - made of plexiglas - connected to servo throw a plastic arm with 2 connection points (one on the
 servo pivot point and another 2.5 cm appart)
- in the exterior point of the upper arm i have 2 spacers (2 pieces of carbon-fiber tube) connected to articulated
 joints (2 pieces). One parallelogram (out of 3) is formed with 2 spacers, 4 articulated joints (2 up, 2 down),
 2 carbon-fiber tubes and, in the lower part, where the joints meet the lower platform, there is another "spacer".
 All of this is called lower arm.
- the lower platform - made of plexiglas. It's an equilateral triangle with some other pieces of plexiglas glued, for
 forming a mounting point for the lower arms.
- in the bottom part we have a working area (the light-brown thing from the top), connected to the support arms
 with a diameter of 40cm, made of wood
- the controller: made of plexiglas, it consists of an 20x4 serial lcd, an Arduino Mega2560, and a pcb that contains
 an infrared receiver, 2 rgb leds and a button.

The robot has 2 main states:
- a manual state: this state allows for independent increments of the xyz coordinates.

Delta Robot - Manual mode
http://vimeo.com/25925860


- a path following state: this state allows the robot to follow a predefined path.
I have selected just a few paths and a few different modes of operation.

Delta Robot drawing - geometrical primitives
http://vimeo.com/25924581


Drawing Fii logo (the logo of my faculty - UAIC Infoiasi )
http://vimeo.com/25924709


Drawing Fii logo - top view (the logo of my faculty - UAIC Infoiasi )
http://vimeo.com/25924803


Drawing circles - top view
http://vimeo.com/25924857

I can talk about this project for days, so if anyone has a question I will more than happy to answer.
Sorry for the long post and the english screw-ups.

Bogdan.

lusian

can you email the code? or some tutorials? my email is eu_ea33@yahoo.com

body28

Hello. Sorry for the late answer.
And yes, i will help you, you will get an email soon.

p.s. does this project suck or there isn't at least a "good job" for me on this forum?
It is quite disappointing.

focalist

#3
Jul 06, 2011, 08:05 pm Last Edit: Jul 06, 2011, 08:25 pm by focalist Reason: 1
That's a pure awesome device... I'm in the process of building something sort of similar, a suspension wall plotter.. two steppers instead of three, but otherwise pretty much the same, in that the head is suspended from a variable length system under stepper control..  http://arduino.cc/forum/index.php/topic,60281.0.html

How are you compensating for the difference in distances radially (in that a movement toward the center is "smaller" than a movement further away)?

I'm currently working on calculation code, which will determine location by using pythagorean theorem and then apply a "correction" to the movement, but it's not quite there yet.  Your device (especially since it used three motors) is MUCH faster than mine, if you operate the steppers at a slower rate do you get increased accuracy?  My largest problem is of course being suspended, it's got a bit of bounce when it moves.

In any case, TREMENDOUS job!  Sweet implementation, it's quite a nice looking device on top of being functional!
When the testing is complete there will be... cake.

lusian

#4
Jul 06, 2011, 08:39 pm Last Edit: Jul 06, 2011, 08:41 pm by lusian Reason: 1

Hello. Sorry for the late answer.
And yes, i will help you, you will get an email soon.

p.s. does this project suck or there isn't at least a "good job" for me on this forum?
It is quite disappointing.

okey. thanks
multumesc.

ohh, by the way, this link doesn't work : http://prezi.com/sckgedbtmy55/licenta-robot-de-tip-delta/

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