Unofficial GCER Feedack Continuation

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Nathan Bernard
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Post anything you wanted to say/ask here and hopefully someone from YAC or KIPR will see it and respond.

I'll start it off.

1) When using two "mav", "mtp", or "mrp" functions one after another for two motors, sometimes there is noticeable leg between when the two motors turn on. Can this be fixed? For example, when given this code:

  1. ...
  2. mrp(0,400,1000);
  3. mrp(3,400,1000);
  4. ...

one motor would turn on slightly before the other and the robot would twitch to the side, turning a few degrees while only one motor is on until the other one turns on.

2) Will the ambient infrared light be checked at the next GCER? This year, either incandescent, halogen, or similar (hard to tell) lights were used. In regionals, fluorescent lights were used. When we got to GCER, all the extra infrared radiation from these lights confused our top-hat sensors. Wee weren't the only ones having this problem. I noticed the room had fluorescent lights, they just weren't used.

3) Why can't computers be used for onsite presentations?

ekmanb
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I would like to reduce bot qualification haggling on the competition table. Knowing how I hate long setup times, I think we could have some bot examination during the on-deck time. I would like a judge to qualify a bot during the on-deck time. They could have a starting box container to set over the bot to check the size (of course folding arms might be a problem). Also during the on-deck time, teams could inspect each other’s bots to register complaints. To do this, you would need a table in front of the on-deck teams on which to set their bots to be inspected.

Bob Ekman

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Bob Ekman, Rockville MD

PiPeep
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Hey natedawg1013!

I'm not from KIPR, however I am in YAC, and I may be able to help you with some of your questions.

Grouped function calls

  • I believe Jeremy's 2011 CBC hacking paper addresses this topic by demonstrating the use of batch control packets with the CBOB.
  • CBCJVM works around this somewhat by doing something like
    1. mrp(0,400,500);
    2. mrp(3,400,1000);
    3. mrp(0,400,1000);
    which kinda keeps the robot straight. If you'd like me to explain how this works, feel free to message me on the community chat.
  • Finally: Yes. This is something that KIPR should provide a better API for, and I believe they mentioned at the GCER feedback that they would consider it.
  • Lighting

    Personally, I don't feel that this problem is big enough to merit the additional effort required on KIPR's part, as it can be solved by proper calibration when you get there and/or proper shielding of the tophat sensor. We used a tophat sensor for detecting the runway on our robot, and had absolutely no problems transferring it to the GCER boards from ours back home. We didn't even have to recalibrate. (granted, we could've just gotten lucky.)

    Computers at the Onsite Presentation

  • I think KIPR wants to ensure that the students are prepared well ahead of time, and requiring printed materials does this.
  • Computers can have issues, and KIPR doesn't want to handle the possibly of someone's computer messing up.
  • If I'm wrong on one of these points, or if I'm missing something, feel free to correct me.

    wmyers
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    As for lighting, recalibration is all that is needed. If you have the same sensor threshold value used in multiple places, then use a #define for easy changing.

    I agree with my fellow YAC member for onsite presentations. I feel it is unnecessary to use a laptop. Using a poster board is best for this. While it is easier to set up a power point, it could lead to problems if the file is lost or the computer dies. Plus acquiring projectors for just the on-site is rather expensive. Even when I went to go do my presentation at GCER, my laptop wasn't happy with the projector. Luckily I did have a copy of my powerpoint already on KIPR's laptop. Essentially what I'm trying to say is that popping open a poster board won't have technical difficulties except for forgetting to bring it.

    Bob, I like your thought on this. Unnecessary time is wasted at the table inspecting robots. And sometimes things could get overlooked just because everyone is in a rush to start the game. Heck, it might even get teams talking to each other more. I really like this idea. As for size constraint, I'm not sure if there is any way to do this. Many teams (such as your beastly robot) need to fold up at the table.

    Wesley Myers
    --
    YAC Advisor
    Botball International Champion 2007 and 2008

    Carnegie Mellon University 2012
    Electrical and Computer Engineering
    Computer Science and Robotics

    Nathan Bernard
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    My issue with the tophat sensor was that I was not using it straight down. I was using it as a "touchless" touch sensor. Like I said, this worked fine in regionals, but at GCER it was awful. So bad, even, that no calibration was possible. It was outputting in the 50-60 range away from anything which is the lowest these go. And a word of warning, shielding a tophat is harder said than done. It's something I had to do to fix it and it wasn't fun. And no, I couldn't use the IR rangefinders. There wasn't enough room and the others were being used.

    Jeremy Rand
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    As PiPeep said, my CBC Hacking 2011 paper discusses how to reduce the latency between motor commands. It's still not 100% perfect, but it should be a major improvement over the official libcbc. Also, that feature is believed to not void the warranty, as it doesn't require any firmware mods. (I can't guarantee this, however.)

    -Jeremy Rand
    Senior Programmer, Team SNARC (2012-2013), Norman Advanced (2010-2011), Norman HS (2008-2009), Norman North (2005-2007), Whittier MS (2003-2004)
    2012-2013 VP of Tech, 2011 President, Botball YAC (2009-2013)
    Mentor, Alcott and Whittier MS

    sgoodgame
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    I wanted to address the robot inspection issue. We could institute a robot check much like FIRST and BEST require, however many robots fold up to fit and many robots are changed after the inspection or in between rounds. It does take time, but I think it is important that the students are the ones who voice their concerns and then have the judges check. Of course we try and catch all of the robots that do not fit into the starting box in the first seeding round, but we do not want our volunteer judges or our staff to have to count parts on every robot entered into the contest. Maybe we could bring a plexiglass cover the size of the current year's starting box and make it available to all teams so that they can check during the practice rounds in the morning. It is sad when you see a robot in the final rounds get challenged on a starting box violation.