I think i got the quad headache too!

[innerbreed]

does anyone have a 3DOF quadruped code for the BASIC ATOM / SSC32! many people have also asked this queston so i dont need to go into detail about the problems faced!

walk dam it, WALK!!!

[km6vv]

Lots of luck! Hexapods are MUCH easier, as they have a statically stable gait.

I think you’ll have to write your own quad code. You might look for this paper:

“ARAMIES: A FOUR-LEGGED CLIMBING AND WALKING ROBOT”

And I think there were some notes on a quad gait here on LM, although I don’t recall where.

@innerbreed

does anyone have a 3DOF quadruped code for the BASIC ATOM / SSC32! many people have also asked this queston so i dont need to go into detail about the problems faced!

I was thinking of doing a Cat Quad. Maybe when I get enough extra legs! I think I can adopt a gait engine for the job.

EDIT:

PDF with Cat gaits. Could be useful for ALL quadrapeds.

genesis-sim.org/GENESIS/iBoG/iBoGpdf/chapt8.pdf

Alan KM6VV

[innerbreed]

yeah id agree with you there my friend. iv already got the EH3r and the CH3r. also i have re-designed a few more hexapods in my time. of course the hex are able to hold a solid COG (centre of gravity). and this is true with my gaits of a hex.

thank you for your input.

[km6vv]

Here’s a French quad that is home made.

b.urbani.free.fr/pagecabot/cabot.htm

Alan KM6VV

[innerbreed]

nice! cute little thing…
the problem i am faced with is not just the fact that it only has four legs but that they are set out in a symmetricaly from the body. the Cabot’s legs reside under the body, as do all cat’s, dogs, mamals in general!

but my design is simmilar to what a spider might be like if you ripped of 4 of its legs, with them spredding out to the side. when the legs are under the body their movements forward rather than swing round! (you with me?)

i can email you a photo if you wish > how do i add photos to this post???!
i have mailed images to webmaster so hopefully they might put them on this site.

[km6vv]

Yeah, cute!

I understand the “sprawled” stance vs. “in-line” (animal) leg arrangement. I think it is more reasonable for quads to have this in-line arrangement. More realistic.

@innerbreed

nice! cute little thing…
the problem i am faced with is not just the fact that it only has four legs but that they are set out in a symmetricaly from the body. the Cabot’s legs reside under the body, as do all cat’s, dogs, mamals in general!

but my design is simmilar to what a spider might be like if you ripped of 4 of its legs, with them spredding out to the side. when the legs are under the body their movements forward rather than swing round! (you with me?)

i can email you a photo if you wish > how do i add photos to this post???!
i have mailed images to webmaster so hopefully they might put them on this site.

Here’s another quad (experiment) I’ve discussed this 'bot with the author on Seattle Robotics list.

oricomtech.com/projects/poco.htm

Did the paper I posted a URL to help? With the gait details, even sprawled legs should be capable of walking!

Yes, I’d like to see a pix of your 'bot. You need to host it somewhere, and provide a link. Or Email me at KM6VV at ARRL dot NET. There are two groups at the bottom of this post that may be of interest, you can also post there!

Alan KM6VV

[innerbreed]

all true my friend! inline is ‘like you say’ easier! ill try email you photos…
bare with me.thanks again.

[snailkeeper]

@innerbreed

i can email you a photo if you wish > how do i add photos to this post???!

Here are image posting instructions:
lynxmotion.net/phpbb/viewtopic.php?t=2230

[km6vv]

Some notes on the above 'bot from my French-speaking, DIY hexapod building friend:

@Monet

Very cute! The word cabot is slang for (chien) dog.
He says he was amazed by demos of ASIMO and that’s what got him
interested in robotics. It was easier to work on a quadruped than a biped.

It uses 15 S3003 Futaba servos. The legs have three degrees of freedom.
The head uses two servos and the tail one.
The processor is an Atmel ATMega8515.
It’s programmed for 8 levels of servo speed.

The leg brackets are made of aluminum. He has two pivot joints like we
do with some brass sheet double-sticky taped to the bottom of the servo
opposite and on-axis of the servo horn with a brass nut soldered on.

I like his toe design which have FSRs (Force Sensor Resistor). He says
that he used them to initially find the center of gravity by adjusting the body
back and forth relative to the legs and then does not use them any more.

It uses 5 NiMH 2500mAH cells that run it up to an hour.
There’s a TSOP1736 IR receiver for driving commands using a TV or
VCR remote as a controller.
He liberated a ‘bark’ module from a stuffed toy which feeds a small speaker.
He has 3-color LEDs for eyes which are the battery level indicator.

The nose is an infrared motion detector.

In the mouth is a Sharp GP2D02 IR distance sensor (~2.5 ft).
Because the head can tilt down it can double as an edge finder.

The ears are shaped like blinkers and house a couple of light sensors.
It uses them to find light sources directionally. There’s a routine that
puts the bot in ‘guard dog’ mode when light intensity is minimal.

There’s a conductive strip under the chin that feeds an input to branch
it into a ‘happy’ routine. (cute)

There’s a microphone under the jaw that is only activated when no
servos are being moved.

The PC programming port is an RS232 connector on it’s butt. It’s
placement evolved to allow it the best freedom of movement
during program and movement development.

The on/off switch is placed where it defines the dog as a male.
See small black slider switch at “La Zigounette”

Microcontroller programming is done using FastAVR Basic
His movements are developed manually using a VB6 tool with sliders
(available as a download from his website).
His comm protocol is described in a linked PDF .
All project information is available to look at.

Alan KM6VV