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Stobs
04-30-2010, 05:01 PM
I've noticed that some biped robots are designed to roll the outer edge of their foot pads downwards as each leg is lifted and some maintain a static foot pad position relative to the lower leg. Would someone be willing to explain the pro's and con's of why one would choose one design over the other? If I had to guess before hand I would say it's to help maintain surface contact as long as possible through the stepping motion, thereby minimizing the duration in which the robot could possibly tip over, but as I'm pulling information together to build my first robot I'd rather not guess. :}

PS: I'm presuming the pads are actively rotated, rather than using offset pivot points with some sort of tab/bump stop to set the standing position, no?

lnxfergy
04-30-2010, 05:19 PM
Most of the ones that do drastic roll of the outer edge, are actually shuffling severly -- they reduce the contact with the ground and slide the edge of the foot forward, still in contact with the ground.

-Fergs

Stobs
04-30-2010, 05:24 PM
Then that denotes a reduced degree of mobility, as either a compromise to maintain a higher degree of stability or the designer/fabricator of the robot has yet to attain the ability to implement higher degrees of movement?

DresnerRobotics
04-30-2010, 05:26 PM
Keep in mind that shuffle gaits don't work well on surfaces that are not rather slick. The new flooring we used for mech warfare was pretty smooth but not necessarily 'slick' as it was painted in a flat paint.

Stobs
04-30-2010, 05:32 PM
Ok - thank you both for the replies; very useful info in helping me to layout my degrees of freedom. :)

muc
05-02-2010, 05:35 PM
Andrew,

What was the floor material?

DresnerRobotics
05-02-2010, 05:51 PM
4x8' 1/2" drywall sheets laid out in a 16x16' area. Joined via joint tape + plaster, sanded at seams, then painted using flat black latex paint. It was pretty smooth and even (much more so than the bare flooring there), but certainly wasn't 'linoleum slick'.

Stobs
05-02-2010, 06:22 PM
Then was the reason people weren't wearing shoes within the arena itself because we wanted to avoid sinking the bb's into the drywall sheets?

DresnerRobotics
05-02-2010, 07:01 PM
Then was the reason people weren't wearing shoes within the arena itself because we wanted to avoid sinking the bb's into the drywall sheets?

That and scuffing up our perdy floor paintjob :P

Stobs
05-02-2010, 07:06 PM
lol :) The arena was awesome :) [EDIT] If a different material is desired there's lighter and much more durable products to choose from. I'm very familiar with building materials and have left-over odds and ends from various jobs, so I could easily test some material/paint/coating options and offer up some recommendations.