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I'm trying to balance my bot. — Parallax Forums

I'm trying to balance my bot.

roughwireroughwire Posts: 78
edited 2007-01-10 22:55 in BASIC Stamp
I'm currently working on trying to make my boe bot (board of ed), balance on two wheels while controling its movement with some ir recievers and a universal remote, and I'm eventually get one of those sugar cube cams to put on it. But for righ now,·I have at my disposal, a lego NXT kit and my little boe bot (my avitar) to make the boe bot balance. So·what I'm trying to say is,·is it possible to convert the lego ultrasonic sensor with a kind of telephone jack so I can use it on·my board of edjucation?··········································································· P.S.·· I'm asking cause I don't have the time or money to buy the PING......·

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MIKE

Comments

  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2007-01-10 17:34
    roughwire,

    I would recommend focusing on one project at a time…In this thread you mention not having any time and in another thread you say the same thing asking for help on an unrelated subject. You may want to take on one thing at a time and focus on the task until completion. I hope this helps. Take care.

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    Chris Savage
    Parallax Tech Support
  • allanlane5allanlane5 Posts: 3,815
    edited 2007-01-10 17:44
    A two wheel balancing robot is really really difficult.
  • Vern GranerVern Graner Posts: 337
    edited 2007-01-10 18:45
    allanlane5 said...
    A two wheel balancing robot is really really difficult.

    I agree.... Unless you just copy someone elses wonderful, simple design! smile.gif

    http://forums.parallax.com/showthread.php?p=623316

    Vern

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    Vern Graner CNE/CNA/SSE    | "If the network is down, then you're
Senior Systems Engineer    | obviously incompetent so why are we
Texas Information Services | paying you? Of course,if the network
http://www.txis.com        | is up, then we obviously don't need
Austin Office 512 328-8947 | you, so why are we paying you?" ©VLG
  • allanlane5allanlane5 Posts: 3,815
    edited 2007-01-10 19:00
    Brilliant Vern, I may try that myself. The key point here is that the Ping sensor is aimed DOWN, toward the table top.

    And that you're using a BS2sx to get a fast enough cycle time. And that you're using NICD batteries to handle the Servo current pulses.

    But that's a really nice, complete solution there. Good on ya!

    Oh, and for the OP -- I don't know the NXT interface.· The NXT is a bit more capable than the BS2 -- you should probably order a Ping sensor from Parallax.·
  • JohnBFJohnBF Posts: 107
    edited 2007-01-10 22:55
    I'd be delighted if anyone tried some or all the design ideas in my balancing bot, many of which, of course, come·from others posting·in this·forum. We're all learning from each other. This is fun precisely because it's hard and requires so many different kinds of structural, electronic, and mathematical things to come together.

    In the meantime, I really wanted to tweak the PID formula based on something better than trial and error. So I attached a Parallax eb500 bluetooth device and got it talking to my PC. I'm capturing data in Windows Hyperterminal and sending the data to Excel.

    Attached is data from about two fifths of a second as the bot was balancing. At that point the PID formula was as shown in the·pBasic listing in my Completed Projects posting. Since then I've been tweaking away, based on real data. I was particularly surprised at the behavior of the derivative term, and I think there's a lot to improve on that I would never have figured out by trial and error.

    I will post more when I'm a little further along.

    /John
    pdf
    pdf
    data while balancing jan 9 07.pdf
    16K
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