Shop OBEX P1 Docs P2 Docs Learn Events
Erco's Ultrasonic Orbit Challenge — Parallax Forums

Erco's Ultrasonic Orbit Challenge

Martin_HMartin_H Posts: 4,051
edited 2014-02-05 04:05 in Robotics
The rules of the challenge are simple. The robot must orbit at a fixed radius (18" to 24" suggested) around a compact object like a large soup can, canister, or oat meal box. No wheel encoders are allowed and distance from the central point is controlled via an ultrasonic or other distance sensor (e.g. laser, infrared).

My entry is below:

Note that I killed two birds with one stone on this one as it is also my hack the halls video.
«1

Comments

  • ercoerco Posts: 20,255
    edited 2012-12-11 17:01
    BRAVISSIMO! You did everything in this one video, and the falling snow is classic!

    In another thread, Gareth challenged me to do a spiral (using stepper motors). You could borrow from John's (jdoleki's) previous video and spiral tinsel garland around the tree as you orbit and spiral in. His robot was stationary and he spun the tree, but this is simpler.

    Martin_H, fantastic job. WOO-HOO!
  • Martin_HMartin_H Posts: 4,051
    edited 2012-12-11 17:44
    erco wrote: »
    BRAVISSIMO! You did everything in this one video, and the falling snow is classic!

    Thanks! The snow and antlers on the robot were my son's idea.

    I'm fairly confident that I could do a linear spiral using the Ping))) and a compass module. The only thing that would change in my source code is increasing the orbit radius as the compass heading changes. Since the CBA has both sensors I wouldn't need to rewire anything. I keep finding myself going back to the BS2 for quick projects like this one as PBasic is so goof proof, although the math for a logarithmic spiral would probably be beyond the BS2.

    OK Duane, Tommy, Garth, and anyone else, let's see your challenge video!
  • ercoerco Posts: 20,255
    edited 2012-12-11 18:44
    @Martin_H: You're simply the best at starting the "erco challenge" threads.

    What say you start a new thread about the "Mail 20 bucks to erco" challenge and I cut you in for 30%?

    BTW it's probably best if we just keep that between you and me in this PM.
  • ercoerco Posts: 20,255
    edited 2012-12-11 18:45
    Oops. Oops. Oops.
  • Martin_HMartin_H Posts: 4,051
    edited 2012-12-11 19:05
    erco wrote: »
    Oops. Oops. Oops.

    Too funny.
  • SlyskyOneSlyskyOne Posts: 8
    edited 2012-12-12 01:04
    @Martin - Well done! The snow made is all the better!
    erco wrote: »
    Oops. Oops. Oops.

    Haha! This is the humor I enjoy.

    I think this would be an interesting challenge to partake in.
  • TtailspinTtailspin Posts: 1,326
    edited 2012-12-16 09:52
    I think that kind of money would offer to much power to erco and would only serve to corrupt... Imagine erco not needing to find "deals"...


    Hey martin, I am not ignoring your Ultrasonic Challenge, I do want to try this.
    It's just that I am knee deep in Audio Land right now, I just got my hands on one of those little FM Radio chips from parallax,
    and I am trying to put it together with an LCD, a 44 watt amplifier, a Pre amp W/ Bass,Treble,+Volume, and the associated power supplies.
    Oh and it all has to fit into an old tool box... It is a fun challenge all by its self. :)

    But, that is not your problem, and you probably just want to see video of my robot going around an IR beacon...
    If you could please stand by for a week or two, I am sure I can shoe horn this into my schedule.
    Now if I could just remember where I put my schedule and shoe horn...:innocent:


    -Tommy
  • lardomlardom Posts: 1,659
    edited 2012-12-16 10:23
    What about the micro? Are steppers OK?
  • Martin_HMartin_H Posts: 4,051
    edited 2012-12-16 13:33
    Tommy, looking forward to seeing a video when you have a chance.
    lardom wrote: »
    What about the micro? Are steppers OK?

    Good ahead If it's all you have. But if possible work in some sort of feedback to an external navigation point.
  • lardomlardom Posts: 1,659
    edited 2012-12-17 09:09
    Quote by Martin_H
    ..if possible work in some sort of feedback to an external navigation point.
    Sensors are by far the biggest challenge. If it was something like a 'pick and place' machine I could use encoders. I personally might want to detect a chair leg or something round like a ball which is not so easy. The code I wrote will move a robot in a circle because 'radius' is used in an equation. I'll have to watch and learn how to make good use of sensors.
  • ercoerco Posts: 20,255
    edited 2012-12-17 09:15
    It might be far easier than you think, even with steppers. I'm betting that a simple wall-following routine will suffice. One sensor, two subroutines. Object detected within range, go straight, object not detected, spin in place toward object so sensor will reacquire and reduce distance to target. Or vice versa, depending on whether you want the object to lead or lag.

    I hope to get my stepper boe bot running today, so I'll be able to try this out soon. I might use a Sharp IR sensor in digital mode to speed up sampling, so it will orbit at a much closer radius.
  • lardomlardom Posts: 1,659
    edited 2012-12-17 11:37
    @erco, The electric bike and the Hanoi robot arm you built were pretty good. You don't follow the crowd. I like the challenge of adding something new or a little different. One thought is "What about pan/tilt Ping?" "How much resolution can I get?" On top of that I still have to adapt the chassis to a 'tail-ball'.
  • ercoerco Posts: 20,255
    edited 2012-12-23 22:50
    Here's something only vaguely related to the title. More wall-following than orbiting, and it uses a Sharp IR sensor, not ultrasonic. Worst of all, it uses "another" processor. But hey, it was quick and it's all in the spirit of Christmas. At least I have something up on the board now, albeit low-hanging fruit: Martin_H has already outdone me. Let's see YOU do better!
  • Martin_HMartin_H Posts: 4,051
    edited 2012-12-24 03:41
    Erco, given the scarce number of entries we'll accept it.

    Hmm, robots using a BS2e and PICAXE (shudder) have completed the challenge, while the Propeller chip has been notably absent. Do I hear a sound? bock, bock, bock, bock, bock, begowwwwk
  • lardomlardom Posts: 1,659
    edited 2012-12-24 08:10
    @Martin_H, I work with Propellers. I just started experimenting with sensors after seeing this thread so it may take a few weeks! I ordered two Sharp IR sensors but I'm working with a standard 'emitter/reciever' pair while I wait. My first try will be far from perfect so please don't kick me to the curb!
  • ercoerco Posts: 20,255
    edited 2012-12-24 08:12
    Larry: A Propeller? You really should upgrade to the Stamp. :)
  • lardomlardom Posts: 1,659
    edited 2012-12-24 09:51
    @ erco, :smile: I had that in mind when I wrote I hope I don't get kicked to the curb. I also like steppers. I reread the Pbasic code from my first project and it's pretty tough to understand. I amazed myself with that project "I can program!" and wanted to see what else I could do which is why I tried programming Propellers.
    Sensors are a big challenge which I can't resist. I have a lot of studying to do.
  • ercoerco Posts: 20,255
    edited 2013-12-28 11:20
    This "dead thread" is worth resurrecting since:

    1) It's too cool to leave buried, and
    2) The new walking Spider bot I'm working on will (if all goes well) orbit around:

    a) one can to do this challenge, and
    b) two cans to do the figure 8 challenge.

    Any other takers? Martin? Larry, we never heard back from you!
  • Martin_HMartin_H Posts: 4,051
    edited 2013-12-28 15:33
    erco wrote: »
    This "dead thread" is worth resurrecting since:

    1) It's too cool to leave buried, and
    2) The new walking Spider bot I'm working on will (if all goes well) orbit around:

    a) one can to do this challenge, and
    b) two cans to do the figure 8 challenge.

    Any other takers? Martin? Larry, we never heard back from you!

    I'm a game. Since I've already done the single can, I will do a figure eight around two cans. I will use my trusty CBA BS2e robot because I'm pretty sure I can nail it without much work using that bot. I can't work on it until next weekend because right now I'm working on a good code interpreter and I've nearly got it.
  • lardomlardom Posts: 1,659
    edited 2013-12-28 22:41
    Whew. It's been a year since I've posted. I thought nobody would notice my absence. While trying to solve the navigation problems I started animating again to give myself a break. Just a short break. The problem is I like to do both things a lot. The break turned into a year.
    Meanwhile the company that makes the software sent me a copy of the latest version and invited me to submit some of my work for possible display on their website. My unfinished robot sits 2ft from me always in view but the capabilities of this new version are still being discovered and that's the part I like the most.
    Anyway, that's what happened to me. I hope to rejoin the forum soon.
  • ercoerco Posts: 20,255
    edited 2013-12-29 08:07
    lardom wrote: »
    Whew. It's been a year since I've posted. I thought nobody would notice my absence.

    Well you figured wrong, Larry! :) At least you're still lurking... Sure, have fun animating, but don't forget your Forum pals! We're here to help. Happy New Year. 2014 is the year you solve your bot's navigation issues.
  • ercoerco Posts: 20,255
    edited 2013-12-29 15:25
    Beware. The Spider robot controller has become self aware while the twins remain blissfully unaware.
  • lardomlardom Posts: 1,659
    edited 2013-12-29 22:38
    Your twins are talking now. I bet you're having a ton of fun!
  • ercoerco Posts: 20,255
    edited 2013-12-31 21:13
    erco pulls a Kobayashi Maru, changing the parameters of the challenge to suit my own evil needs. My walker orbits two different points (making a figure 8) using a Sharp IR sensor. Killing several birds with this one robotic stone. :)
  • Martin_HMartin_H Posts: 4,051
    edited 2014-01-25 18:18
    Erco, I didn't forget about the double orbit challenge. I just got a chance to fire up the CBA robot and give it a try. As expected that trusty BS2e powered bot came through in no time.
  • ercoerco Posts: 20,255
    edited 2014-01-26 17:06
    Nicely done, Doctor! :)

    Another win-win for orbiting plus the figure 8 challenge!
  • Martin_HMartin_H Posts: 4,051
    edited 2014-01-27 11:14
    Hey thanks! I have to say that one thing I really like about my BS2 robots is how quickly you can bang out projects with them. That was maybe two hours work and the hardest part was a bit of trial and error to find how to time the right to left switch.
  • ercoerco Posts: 20,255
    edited 2014-01-27 15:39
    Martin_H wrote: »
    I have to say that one thing I really like about my BS2 robots is how quickly you can bang out projects with them.

    Amen Brother! There will always be a place for Stamp-based bots.
  • Phil Pilgrim (PhiPi)Phil Pilgrim (PhiPi) Posts: 23,514
    edited 2014-02-04 21:53
    Martin,

    You posted a video in another thread that totally inspired me:

    My robotics students had just completed some basic Ping))) stuff, and I needed a project to build upon what they had learned. Based upon your work, I came up with an "individual pursuit" race around an oval course. Here's a photo of the course:

    attachment.php?attachmentid=106712&d=1391579718

    I found a 2' x 4' mat at the hardware store made of bamboo slats adhered to a cloth backing. I sawed it into three 8" x 4' strips. The course barrier uses two of them, held together by spring clips. The whole thing rolls up compactly for transort to the school.

    Attached is the handout I prepared for the kids to work from.

    Thanks for the inspiration!
    -Phil
    pursuit_wall.jpg
    648 x 486 - 85K
    pdf
    pdf
    5 February 2014.pdf
    570K
  • Martin_HMartin_H Posts: 4,051
    edited 2014-02-05 04:05
    Phil, you're welcome, and I'm glad my video inspired you! This also sounds like a really fun contest, hopefully it will catch on!
Sign In or Register to comment.