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IR Beacon Tracking — Parallax Forums

IR Beacon Tracking

ercoerco Posts: 20,255
edited 2012-10-03 09:21 in Robotics
First test using twin TSOP4038 IR receivers to track to a simple LM556 beacon (blue LED on door). Seperately, it uses a Sharp IR distance measuring module as a digital proximity switch. When it gets within 4" of the door it does an about face and drives away for 6 seconds, then repeats the locate & track cycle. Not bad for a first test, I have lots of variables to adjust.

http://www.youtube.com/watch?v=-BKikozfdds

Comments

  • ElectricAyeElectricAye Posts: 4,561
    edited 2012-09-21 05:54
    erco wrote: »
    First test using twin TSOP4038 IR receivers to track to a simple LM556 beacon...

    Very nice! How are the IR receivers positioned? Just a simple V arrangement? Any lenses involved? Do tell.
  • Matt GillilandMatt Gilliland Posts: 1,406
    edited 2012-09-21 10:01
    Nice erco!
    (but where's the plywood? all i see is plastic)
    -MattG
  • ercoerco Posts: 20,255
    edited 2012-09-21 10:20
    Brave new world! That $15 chassis is part of a series of articles in ROBOT magazine. Part 4 (final part) due out any day now.
  • mindrobotsmindrobots Posts: 6,506
    edited 2012-09-21 10:23
    "Part IV - Moving Your Tested Hardware To Its Final Plywood Chassis"
  • Matt GillilandMatt Gilliland Posts: 1,406
    edited 2012-09-21 10:25
    Rick = Man after my own heart (redwood).
    -MattG
  • mindrobotsmindrobots Posts: 6,506
    edited 2012-09-21 10:32
    IF I ever get my wood shop back, I have the Classic American Robot planned, maple, cherry, oak and walnut with brass hardware.......IF.......
  • PublisonPublison Posts: 12,366
    edited 2012-09-21 10:37
    mindrobots wrote: »
    IF I ever get my wood shop back, I have the Classic American Robot planned, maple, cherry, oak and walnut with brass hardware.......IF.......

    SteamPunk no doubt. :)
  • ercoerco Posts: 20,255
    edited 2012-09-21 11:22
    Matt Gilliland wrote: »
    Rick = Man after my own heart (redwood).
    -MattG


    Hold it right there, Mister! You're the guy who switched Ken's beautiful (ply)wood robot chasses to delrin and started the whole rift!
  • GordonMcCombGordonMcComb Posts: 3,366
    edited 2012-09-21 12:16
    I'm just impressed you got a Magician chassis to go in a more-or-less straight line!

    Anywho, since plastics come from petroleum products, which is from oil, which is (in part) from millions-year-old forests that turned into peat and oozed its way into the ground, your robot is indeed made of wood. And maybe a pterodactyl.

    -- Gordon
  • ercoerco Posts: 20,255
    edited 2012-09-25 01:14
    Three beacon tracking demo. As it turns out, a weak IR signal is better than a strong one to avoid reflections & ghosts. Detection range is 20+ feet from robot to beacon. Ultrasimple beacons are individually coded so robot can distinguish between at least 4 different beacons. Front LEDs show active steering direction towards beacons. Front mounted Sharp IR distance module used here in digital mode as a quickie proximity sensor. Details in ROBOT magazine Nov/Dec plus online bonus material shortly, should be at http://find.botmag.com/111207 I should be able to get a BoeBot working just like this once time permits.

    http://www.youtube.com/watch?v=3rHuFFe6HRc
  • Martin_HMartin_H Posts: 4,051
    edited 2012-09-25 06:17
    That's neat Erco. I like how you distinguish between beacons to allow navigation around the room. It's sort of like following an invisible line between the beacons. I've seen people do three point triangulation using different beacon ID's and compass angle, but that seems overly complicated, just add more beacons and be done with it.

    BTW Your put my IR beacon project to shame. I bought a pair of the Pololu beacon/sensor pairs and started working on simple single point navigation. But I can't reach this level of complexity with a single beacon.
  • Matt GillilandMatt Gilliland Posts: 1,406
    edited 2012-09-25 07:59
    Anywho, since plastics come from petroleum products, which is from oil, which is (in part) from millions-year-old forests that turned into peat and oozed its way into the ground, your robot is indeed made of wood. And maybe a pterodactyl.
    Gordon the peacemaker...I say Truse!

    Nice work erco!
    -MattG
  • ercoerco Posts: 20,255
    edited 2012-09-25 20:58
    Thanx boyz. Here's some quickie sensor detail for the construction article. I found the rotary sensor mount quite handy for experimentation. Beacon schematic attached for your consideration.
    IRbeacon.jpg
    630 x 550 - 48K
  • ercoerco Posts: 20,255
    edited 2012-09-29 09:46
    ROBOT magazine has uploaded the Bonus Content on this article to their website at
    http://find.botmag.com/111207 and there is more info and specific part recommendations there for anyone seekin' beacon info.
  • Martin_HMartin_H Posts: 4,051
    edited 2012-09-29 10:22
    Erco, this morning I got my IR beacon program working. Here's CBA tracking a Pololu beacon while using Ping))) to avoid a Parallax box which is blocking it:
  • ercoerco Posts: 20,255
    edited 2012-09-29 12:50
    Great job! Rich guys like you can afford all those fancy Pololu beacons, but poor guys like me have to make our own! :)

    JK, I like your demo. What's next?
  • Tom CTom C Posts: 461
    edited 2012-09-29 15:54
    For a very simple 38-40KHz beacon modulator try this: http://www.rentron.com/remote_control/TX-IR.htm
    Regards,
    TCIII
  • Martin_HMartin_H Posts: 4,051
    edited 2012-09-29 16:42
    erco wrote: »
    Great job! Rich guys like you can afford all those fancy Pololu beacons, but poor guys like me have to make our own! :)

    JK, I like your demo. What's next?

    Lazy more than rich. I've been meaning to build navigation beacons since the first time I saw your 556 timer circuit. I like building robots and don't mind programming, but building boards from scratch always slows me to a crawl. I'm going to switch over to the 4x4 instead of CBA, add more collision sensors, and improve the navigation software. I can use the Pololu beacons to debug it and act as the goal.

    The idea is to build a smart "horse" robot that has 4 pin reins that any rider can control. For example I bought a GPS a while back and plan to build a GPS rider. You feed the GPS a way point which acts as a virtual beacon, and the robot will travel there under the direction of the GPS rider. Or you could have a remote control rider that directs the horse, but can't command it to go into the ditch. The 4x4 will be ideal for this sort of thing.

    The Basic Stamp 2 should be good at this job, while the GPS functions could under control or a Propeller chip or that brand X MCU I also know how to program.
  • photomankcphotomankc Posts: 943
    edited 2012-09-29 19:58
    This is great info! I want to have a charging dock and this would be just the ticket to let the bot home in on the charger. Thanks for sharing all the designs.
  • ercoerco Posts: 20,255
    edited 2012-10-02 23:33
    Now it's a Speakin' Beacon Seekin' robot. :)
  • Martin_HMartin_H Posts: 4,051
    edited 2012-10-03 05:48
    That's neat speech synthesis always makes more of an impression that displaying the words red, yellow, blue on an LCD. I also like the way you mounted the IR distance sensor on a pivot to switch between wall following or collision mode. I'll have to copy that in the future.
  • GordonMcCombGordonMcComb Posts: 3,366
    edited 2012-10-03 08:55
    Ach! I thought you had something here with your Bacon-Seekin' Robot. Finally, a robot everyone ('cept vegans) would want!

    -- Gordon
  • ercoerco Posts: 20,255
    edited 2012-10-03 09:21
    Martin_H wrote: »
    I also like the way you mounted the IR distance sensor on a pivot to switch between wall following or collision mode. I'll have to copy that in the future.

    That'll cost you a dollar, same as every Ebay referral! :)
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