Author Topic: Need advice on Balance-bot desing (Read 3725 times)

mackmelby · « **on:** February 01, 2008, 10:10:19 PM »

Im looking for the most cheap, simple, inexpensive way of building a balance bot. I'm thinking of using a ground sensor "cane" or attaching a slide-potentiometer to a hanging weight...may be a bit unstable...but i can always make the bot taller or more top heavy...so far, I have purchased two 100rpm 14 oz-in motors with 2in wheels and a speed controller. Robot does not need to turn, only forward-backwards balancing. ANY ADVICE WOULD BE APPRECIATED

SmAsH · « **Reply #1 on:** February 01, 2008, 10:14:26 PM »

please explain more about what you want...what is your budget? what is your experience? do you have the right tools/equiptment?

HDL_CinC_Dragon · « **Reply #2 on:** February 01, 2008, 10:36:32 PM »

And what is the final goal you hope to achieve?

frank26080115 · « **Reply #3 on:** February 01, 2008, 11:20:53 PM »

my idea involves a sharp IR range finder, a microcontroller with PWM and ADC, and a motor with driver

do some research on how the range finder works, how to use ADC on a microcontroller, how to use PWM on a microcontroller, all of these are on this site

SmAsH · « **Reply #4 on:** February 01, 2008, 11:30:08 PM »

lol the goal is probibly only to make the robot stand up and balance lol hdl_cinc_dragon

HDL_CinC_Dragon · « **Reply #5 on:** February 01, 2008, 11:43:44 PM »

Quote from: SmAsH on February 01, 2008, 11:30:08 PM

lol the goal is probibly only to make the robot stand up and balance lol hdl_cinc_dragon

well duh lol, but I mean is their a greater objective? Perhaps a specific circumstance?

SmAsH · « **Reply #6 on:** February 01, 2008, 11:50:45 PM »

oh what to like move to a place or sence something?

HDL_CinC_Dragon · « **Reply #7 on:** February 02, 2008, 02:11:13 PM »

basically

So how 'bout it Mack? We need a little bit more information to help you out properly

SmAsH · « **Reply #8 on:** February 02, 2008, 03:57:31 PM »

well the first thing we need to know is your budget. if your a beginner and have only made one or two robots expect to spend $100 upwards. lol. second thing: your design you want/goals to achive. third please show us a layout. like design of it. fourth...sorry normally i can only count to four

edit: heres a quick cad i did a model i recently saw on the web. (and the downloadable cad for people with google sketchup)

Rebelgium · « **Reply #9 on:** February 02, 2008, 06:01:02 PM »

Also search the forum and the web to look for inspiration.
The robot smash drew is also in the video forum on SoR.

SmAsH · « **Reply #10 on:** February 02, 2008, 06:14:12 PM »

yes! thats it! i've been wondering where ive seen it before. ya http://www.societyofrobots.com/robotforum/index.php?topic=2543.0

mackmelby · « **Reply #11 on:** February 07, 2008, 01:44:08 PM »

Ok...I don't have an extremely limited budget...maybe $300 + parts that I already have, ...the balance-bot only needs to stand up straight and also needs very quick response. The big limitation here is that I suck at programing/electronic stuff (only because I end up frying expensive equipment) So my plan is simple,the robot will be controlled by one main sensor, probably a potentiometer hooked to something that changes when robot tips, like a hanging weight or a stick that drags on the ground. I was wondering if there was a more accurate way of measuring gravity or tilt without getting into too much programing. I'm doubting that the hanging weight is gong to work very well so tell me what you think. (Ill try to post some cad drawings soon)

mackmelby · « **Reply #12 on:** February 07, 2008, 02:34:48 PM »

Ok, ill Let you guys in on what I'm really building...But for now, I have to work on the prototype that operates on two wheels;)

mackmelby · « **Reply #13 on:** February 07, 2008, 08:56:51 PM »

Also...sorry for the late response...Im used to forums that take weeks to respond..lol JK

bukowski · « **Reply #14 on:** February 08, 2008, 11:16:40 AM »

That is an ambitious project, and something I (and probably a whole lot of other people) have thought about. First off, I think your Pot idea wont give you ideal results, especially if you add in another axis. You would do much better with a set of MEMS rate gyros and accelerometers, and they are getting very affordable if you cant scavenge the parts. Keep us updated though, it looks interesting!

mackmelby · « **Reply #15 on:** February 08, 2008, 09:28:38 PM »

Ok...so, If Im going to experiment with gyros+accelerometers, what kind of microcontroller(s) should I use (where to buy) If I have never programed a microcontroller before? ...I think the biggest thing i have ever programed was a screen saver that popped up random letters all over the screen... lol

..So Im wondering if I have the skills to tackle this project(I think i do as long as i dont end up frying anything) any suggestions on gyros, accelerometers and motor-drivers and where to get them would be helpful. Also need to be done by less than a month lol so ill be working hard and fast.

TrickyNekro · « **Reply #16 on:** February 09, 2008, 03:46:28 PM »

A friend of mine got a nice balancing robot with just some reflect sensors!!!
Code is the problem...
And try to place heavy objects like batteries was low as possible...
Less dynamic energy in your robot means easier balancing!!!

Cheers, Lefteris

Trumpkin · « **Reply #17 on:** February 09, 2008, 03:48:28 PM »

you could also use Sharp IR pointed at the ground to detect your tilt.

mackmelby · « **Reply #18 on:** February 09, 2008, 05:33:30 PM »

TrickyNekro : I think I'm going to run some dynamics tests before I build the chassis because for one thing, I read all sorts of opinions about what people think the weight distribution should be and everyone seems to have their own opinion. Also it's a science fair project, any extra data is helpful. So maybe Ill post the results of my dynamics test if your interested.

Rambo · « **Reply #19 on:** February 13, 2008, 04:33:14 PM »

Hey, i'm thinking about building a balance bot with Sharp IR sensors to detect tilt and stumbled across this forum whilst doing a bit of research. Has anybody tried building a bot with IR sensors or is a gyro and accelerometer combo the best way to go.

How are the tests going mackmelby

mackmelby · « **Reply #20 on:** February 15, 2008, 09:39:35 PM »

Well...Im sure an IR sensor would be good for a smaller scale balance-bot, but idk..If you want an example of a simple IR balance-bot, type "Equibot" in youtube or Google...I think the equibot is documented somewhere (it's not hard to find, just search google) And as for the dynamics tests...Adding weight to the top of robot causes robot to fall slower. If you want a simple way of proving it for yourself, just take a broom and balance it with heavy end up...easy...and then try heavy end down...Its more difficult...Also I found out that your motor speed must be in proportion with the height of your robot.

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Author Topic: Need advice on Balance-bot desing (Read 3725 times)

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