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  • Collision avoidance

    With all of the movement during autonomous, collisions are almost inevitable. In particular, both alliance partners will be placing their team marker in a relatively small area at or near the same time. Also, parking in the crater is a great unknown since theoretically all 4 bots could attempt to park in the same crater.

    Any ideas on ways to avoid collisions?

  • #2
    Develop a couple of path options. Discuss with alliance partners in advance of qualification matches and see what fits best. Send out other team members to watch your opponents during matches and note what their autonomous does. Now you're armed with data and can make informed decisions. Okay so sometimes it's still going to be an autonomess!

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    • #3
      Thanks for the input! We have considered those options. Competition days are usually pretty hurried and stressful. Working out path options with all alliance partners is an option, but will certainly be challenging with the hectic schedule. I had not thought of scouts on the opponents for their routes. I knew they would not be likely to volunteer the information. Also, they could also have various programs, so the route the scouts noted may or may not be the one they use in your competition.

      I have also considered pool noodles zip-tied to the outside frame to minimize damage in the case of a collision. We have a little wiggle room on the 18 inch cube, so that may be an option. A bit on the ugly side, but an option, nonetheless!

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      • #4
        Putting a delay in some of your auto routines is another strategy, so your partner will be gone before you try to do your tasks. I don't think bumpers are required. Robots usually go fairly slowly in order to be accurate. However, tipping and entanglement would ruin the whole match.

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        • #5
          I think ball side robot should use alliance crater while block side go to opposing alliance crater. Drawback is block side robot will waste few seconds in teleop to return back to alliance zone for scoring but if all do this then less chance of collisions

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          • #6
            We have not had our first competition yet. For those of you that have competed, has this been an issue? Have there been collisions? Have they affected the outcome of the autonomous scoring? Have they damaged the robots? We have several things in mind to limit the risks, but I am wondering if it has been an issue yet for anyone.

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            • #7
              There have been a few collisions, but typically not too deadly. With a little pre-match coordination, several would-be-collisions can be avoided. I would say there were more bots that tipped themselves by hitting lander legs or flipped due to a high-rear CG and rocking back when parking on the crater. There were also a few cases of bots catching on each other during landing.
              At early qualifiers, a few bots drop and stay at the lander.
              Many more drop and then bum rush the crater or depot - blasting thru the center mineral without sampling. This was by far the most prevalent default auton - very few (perhaps 10-15%) appeared to make an attempt at sampling.
              A few of those that would go to the depot would claim and then just freeze there - this causes potential issues for the partner starting from crater side and arriving at the depot later.
              Others starting at the depot side would then attempt to get to the crater to park. Some of these don't adhere to the suggested paths - going to the alliance side crater instead of the opposition side crater. We even had one team whose coach was hesitant to forego their 10 pt park - even though the interference would cost us a claim, park, and potentially 2nd mineral removal.
              Another note - in early competitions, the refs seem to be either lenient or unaware of the penalty associated with moving the opposition's mineral while attempting to park.
              I suggest going to the competition prepared with maps of your auton routes - including times that you will arrive at each key point. Having this helped us coordinate with a partner - we started crater side, dropped, sampled, claimed, and parked. Our partner started depot side, did default center rush to depot, claimed, and stayed there. By sharing our route timing, they were able to add a delay so that we could be clear before they locked up the depot.
              Finally, we have the ability to clear our partner's gold mineral, but have barely been able to use it. So many teams take the 33% shot down the middle, and aren't able to configure their auton. Often coordinating this would cost our partner a claim+park (15+10) in exchange for a 67% chance of getting 25 for clearing their mineral. As the season progresses, I imagine 2nd claims will become even less useful, as more teams should be able to sample.

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              • #8
                Wow! Thanks for the info!

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                • #9
                  My son found a pattern that may already be public knowledge to most of you. It was new to me, so I thought I'd share it. I'm not sure where he found it, but I believe he did a search of "ftc safe autonomous routes" and it came up. If everyone used this pattern on their autonomous portion, no collisions would occur. In watching an awesome youtube video of some Michigan teams achieving over 300 points, it appears that this team utilized this pattern. This is the pattern he is going with on our autonomous program now, so I thought I'd share with you folks so maybe others will as well.

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                  • #10
                    The suggested path basically goes to the sampling in front of the starting point, turns left to the pictograph, goes to the depot, and skirts the edge of the field to the crater. If all 4 follow this path, the only possible point of collision is the depot, if both robots enter at the same time. They are coming in from opposite directions, so even if they are there at the same time, a collision may be avoided if they don't enter far into the depot. At our first competition, collisions were not an issue. Not many were moving at all during autonomous. As the season progresses, I suspect the more advanced robots will use this path.

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                    • #11
                      https://www.reddit.com/r/FTC/comment..._rover_ruckus/

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