Riding and balancing a two wheeled cycle might seem easy to us human pods, but it actually takes a significant amount of processing for a robo

http://clipnation.com/tiny-robot-rides-tiny-bicycle/

I watched the whole video,.. to see if he could stop on his own...
... and he did!...
Yea!....  really cool!... ...

I spoilt it...   ...

"Luke,.. I am your father"... (sic)... ...

justin_o_guy2 wrote on 10/26/12 at 22:40:21:


It was sent to me by the computer lab manager at the University of WA (a former co-worker at Apple), but I have no idea from whence it originated?

BTW, for the musically inclined, my old friend Pat is also a Luthier.  Check out some of his one-of-a-kind custom made guitars...

www.patfosterguitars.com/

Dave wrote on 10/28/12 at 09:32:57:

Awwww- beat me to it.

Dave wrote on 10/28/12 at 09:32:57:

Counter steering works by moving your COG into the direction of your intended turn, but I'm not sure that same dynamic comes into play at slow speeds?   It seems to me that as you start to lean, you just steer into that direction to push your balance and COG back to level again.  I don't know?     I noticed a small bar (rod) behind the robo that looks like it might be a sensor of some sort.  This might be a sonar sensor that can accurately detect ground distance differences at the tips?   In any case, it would be fun as heck writing code for that little bugger.

I built a balance robo a couple of years ago that had 2 parallel wheels and a gear reduction DC motor.  The wheels were on a live axle, so the robo didn't turn.  My first attempt was to use two tilted mercury switches to run the motor directly in the direction it started to lean.  So while was perfectly upright, neither switch would be closed, but when it started to lean one of the switches would close applying power to the motor in that direction.  I experimented with different angles for the mercury switches, but it still wouldn't work properly.  The robo would start out trying to balance, but quickly digress into out of control oscillations until it fell down.   The problem was I was only taking static conditions into consideration, and failed to factor in acceleration, which is totally dynamic (speed per second per second).   I solved the problem using a microcontroller that calculated integrals for acceleration, and applied pulses (pulse width modulation) to the motor to vary it's torque.   You could even push the top and it would quickly correct its balance - pretty cool!   I want to build another some day, but this time I'll use 2 motors (one per wheel) so it can steer.

ToesNose wrote on 10/30/12 at 12:36:22:


I had some viddies and stills, but a couple of years ago my hard drive crashed and couldn't be recovered; i.e., it turned into a "clicker" as the RW head would no longer seek.   I usually keep reasonable backups (every 2 or 3 months), but it caught me totally off guard and those particular files didn't make the cut.   After finishing it, I gave the robo to the local HS for their electronics classes, but I don't know if they still have it?   In any case, it might be a hassle getting it back because the teacher I gave it to isn't there anymore.

verslagen1 wrote on 10/31/12 at 19:33:47:


Well, actually I don't want it back except maybe to retake some pics and viddies to post here.   However, as I mentioned earlier in this thread I want to build another unit with 2 motors, each with their own wheel.   That way it can steer and maneuver while balancing.   I'd rather focus on that project instead of resurrecting the old one, even tho I'll probably give the new one away too.    

Currently I am still working on the tachometer project, to which I have added a clock chip (DS1307) adding time of day (HH:MM) to the instrument.   I'll post an updated pic and description in another thread here in the Cafe.