You might wanna rethink your priorities. You can’t stack what you don’t have. 
Breaking up the landfill- Passive is just fine Skip ahead to the 50 second mark.
Acquiring totes from the landfill- An active mechanism, if built right, should be more efficient than a passive mechanism. The Greenhorns claw mechanism took a very long time to line up in order to acquire a tote. If the lining up process was somehow automated as others have mentioned then I could see a passive mechanism being super efficient. However, even with this automation you generally have a smaller margin of error with a passive mechanism than an active one.
Acquiring Totes from human player: I think there are simple ways to build a passive intake mechanism that can stack totes quicker than the HP can load them.
Overall importance- I think active intake mechanisms are far from vital, yet offer an advantage. They are probably less important than they are most years IMO.
Bottom line on this thread seems to be: speed to acquire a game piece is necessary to be competitive. An active intake is the favorite strategy to achieve this, though not the only one.
I’m not trying to disagree with you specifically, this is just something I have seen on Chiefdelphi several times and I wanted to comment on it.
You can’t simply say, “if an active intake makes you quicker it makes you more competitive”. Because for any improvement to a robot you have an “opportunity cost” (or, what you gave up to get it). If making your intake active takes 3 more days then a passive intake, then your opportunity cost is whatever you could have done in those three days. (3 more days of driver practice?) The real question is, “Will making an active intake make me more competitive than anything else I could have spent my time doing?”
I firmly believe that in most cases a passive system’s competitive ceiling is far lower than an active system’s competitive ceiling, and thus worth the tradeoff. Will this year have that case? I guess we’ll find out in 4.5 weeks.
Of course this is all put to the test when we’re dealing with a lower amount of resources.
Build a manipulator/device that takes the human element out of the equation via robot design and/or programming as much as possible.
What’s necessary to be competitive is a pair of drivers that can get the job done. Whatever makes the drivers’ jobs easier helps a lot, of course, but if the drivers can get the job done without the added complexity and weight of an active mechanism, then great.
To preface: we plan on specializing in controlling containers. We have plans to be able to stack totes if necessary, but that is not our primary focus. This year, we chose not to use rollers for our manipulators because the containers and totes don’t run away from you if you bump them like balls or inner-tubes do from previous years. We’re confident that our drivers will be able to render the biggest advantage of an active intake pointless.
I believe that a team’s success this year will hinge more on driver skill and experience than any year in recent memory, so try to get your drivers plenty of practice.
It will, but it’ll still cost you stuff. Our team decided against an active pickup - we found that (at least the ones we were capable of manufacturing) didn’t improve approach angles enough to make it worth it.
–1-2 extra motors/wheels/belts/associated hardware mounted forward will make your robot tippier.
–A few person-days of effort to prototype and attach the active device will cost you driver training and debugging time on other parts of the robot.
–If your active pickup ends up being breakable (and your pickup isn’t usable without it), then it adds a single point of failure on your robot. If you lose effectiveness for 1-2 matches in a season, that brings your totes-per-match average way down.
To a powerhouse team it is a no-brainer: they have ample man/womanpower and cash to make it happen. To a team that has to trade training or testing time for it or skip another mechanism, it might not be the same decision.
I have to agree with Bryan. In every game you have the cycle (wash, Rinse, Repeat).
Now active is a vague term. You can have active, which allows for the robot to come to a game peice and the rollers will pull it in, and you can have an active system which assist the robot in manipulating the piece so the robot better aligned. I would think that being able to have rollers that can assist with turning totes a little, so the robot doesn’t have to do fine moves, will be the biggest help. An active system that pulls in totes can be delayed if the robot has to do all the aligning first.
Good Luck and Have Fun
roger
I have wondered about active intakes for this year’s game. I think there’s a good comparison of Recycle Rush and Ultimate Ascent. In 2013, you could be extremely successful by being purely a human loaded robot - no floor pickup and no active intake necessary. This year is the same but with fewer game pieces available to the human player. Also, loading from the human player will be slower.
This means that each alliance will likely require at least one robot to play without interaction with the human player. This increases value of landfill robots and recycle container robots which will likely require active intake mechanisms.
Still, pure human loaded robots won’t need an active intake if they interface directly with the tote chute.
The question shouldn’t be does it decrease cycle more so then another mechanism would.
I think a lot of people are defining “competitive” as being among the top teams.
I think that being “competitive” means being on a level that you can contribute to a Playoff Alliance significantly - a la Minimum Competitive Concept.
Note that a particular design can be inferior, but the robot as a whole can still be competitive.
So I don’t think that this poll will be productive with different definitions floating around.
I can think of many ways that a robot without an active intake could be a valuable contributor to an Einstein alliance.
Going off of this, I agree. Just adding that your time it takes to acquire totes could end up being proportional to your success but that could be any mechanism, not just intakes to bring totes under robot control.
I will say that I have seen a fair amount of robots/mechanisms that are relying on alignment of fingers in the totes…this could be trouble if your main objective was to be a open field stacker; in another role it might work a lot better. It shouldn’t be an open vote but something your team went over in the first couple weeks of season and could be added later. DO NOT see it as, "Dang we missed a huge part of the game, lets scrap part of our design week 4 and make a new one using intakes…not worth it especially if it compromises everything you have already planned.
-Ronnie
We first decided what our primary function would be. We then decided how fast we thought we’d need to be able to accomplish that primary function in order to be a top robot.
Our goal was to be able gather and stack 5/6 totes and one recycling container (all off the ground) and stack them in under 30 seconds. Recognizing that some of that time would be used simply driving the robot from spot-to-spot, we knew we needed an “aggressive” intake system and lifter. So, we told our engineering team that we needed the acquiring and lifting mechanisms to accomplish the following in about one second:
- Grab totes and bins (even if not perfectly lined-up)
- Bring them in to the stack (we have an internal-bottom stacker).
- Lift the item just over 12 inches, to prepare for the next tote.
We found several ways to accomplish this, but they all had one commonality: They had some sort of active “grabbing” mechanism on the intake. Every possibility that we studied that did not have such a mechanism was not going to be able to gain control of the totes fast enough to satisfy our speed goals.
Could it be done? I dunno. We are always looking for super-simple ways to accomplish things. We just didn’t find it this time.
No, the robot is not finished yet, so we really don’t know if we have accomplished the goals… However, so far it is on track to do so. Hopefully we’ll know by next weekend…