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Line-Racing Robots — Parallax Forums

Line-Racing Robots

ercoerco Posts: 20,257
edited 2016-02-07 21:48 in Robotics
This contest has pretty fast car-type bots with an unusual track, a combination of curvy radiuses, square 90-degree turns, and some discontinuous staggered lines at 0:15 and 0:45. I have no idea what went on there but the robocars had no trouble getting through. Pretty impressive IMO.

Comments

  • GordonMcCombGordonMcComb Posts: 3,366
    Wowzers. Hotwheels on steroids.

    I kept looking for the little disclaimer ... "Not a real flying toy."
  • Martin_HMartin_H Posts: 4,051
    Neat video. You can see how they have the line sensors far out in front to give the robot time to anticipate the sharp turns.
  • ercoerco Posts: 20,257
    See also
  • WhitWhit Posts: 4,191
    The 90-degree turns are unbelievable! FAST!
  • Martin_HMartin_H Posts: 4,051
    In the second video the car cuts some of the turns on the inside radius so much that no part of the car was over the line. It's probably makes it much faster, but some line following contents require that a portions of the robot is always over the line to avoid really aggressive corner cutting.
  • ercoerco Posts: 20,257
    edited 2016-02-08 22:08
    Yes, the car in the second video probably uses a camera vision system to look at the white track ahead instead of the black line line of color. :)
  • GordonMcCombGordonMcComb Posts: 3,366
    The problem with video is that it needs an extremely fast frame rate at that speed of motion (like 250 fps, for even faster), and while it's possible with a really robust ARM controller, I wonder if it's just clever programming for the curves. Equally important for line followers is where the track was, not just where it is. And yes, it's likely the full track it's keeping track of, not just the thin black line down the center.

    OTOH, a"vision" system, if it has one, doesn't need to ingest a full frame. It only really need to process the top 40 or 50 lines. A camera with an orthographic lens, scanning just a few dozen lines instead of the full frame, could create a running (like a piano roll) matrix.
  • ercoerco Posts: 20,257
    Yes sir, in that high-contract environment, a simple Wii-type sensor (or maybe even Roborealm) could see the white track against the blue floor. Looks like a tiny camera on top of that mast.
  • GordonMcCombGordonMcComb Posts: 3,366
    I thought that was a small blue flag on top of an antenna. For a camera it might might too blurry to be useful, unless the frame rate is really high. Even a small mass on top of a thin mast might create lots of vibration, but indeed, that would be a good place for a camera.
  • ercoerco Posts: 20,257
    edited 2016-02-09 18:59
    The poster on the Youtube site makes a few comments about camera & PID, can't tell if he was actually involved or not.
  • GordonMcCombGordonMcComb Posts: 3,366
    From the comments, which are now pretty old, several people asked and he never directly answered. So I suspect he reposted it from someplace.

    Some of these types of events have used stationary cameras and outside electronics that do the mapping. A computer radios back the position information in real-time as the car travels over the track. Still uses a PID (a given for many line followers) and camera, and would also explain the aerial. I suppose it comes down to what the competition was meant to showcase.
  • hazletthazlett Posts: 35
    That was really fast. Impressive!
  • ercoerco Posts: 20,257
    hazlett wrote: »
    That was really fast. Impressive!

    At the opposite end of the speed/impressiveness spectrum is my Meander-Bot, in no rush at all. And no, it's not PID!


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