Wheelless Robot?
 

So my team is debating on whether to have wheels or not. In the rules, it says, "The Robot must include all of the basic systems required to be an active participant in the game - power, communications, control, mobility, and actuation."

Does climbing count as mobility or would the lack of wheels be illegal?

Re: Wheelless Robot?
 

That would be legal.
There was a question in the QA about it.
R01
Q.Do we need a drive-train?
A.There are no Rules that require a drive base.

Re: Wheelless Robot?
 

It should be fine, but it doesn't sound like a very good idea.

Re: Wheelless Robot?
 

Sure, it might be legal as long as your bumpers are in the legal bumper zone.

And make sure that the base of your wheelless robot isn't metal, metal touching carpet isn't allowed.

But a driveless robot won't do very well. An alliance won't want that, even if you could just drive around you become a defense robot.

Re: Wheelless Robot?
 

But then I can use my CIMs for much more important tasks! :rolleyes:

Re: Wheelless Robot?
 

If the only thing you wanted to do in a match is CLIMB, this would be a good way to save weight.

Re: Wheelless Robot?
 

This. And I think a 30-point contribution will tip the scales in the vast percentage of matches.

Re: Wheelless Robot?
 

But since with autonomas, we start out next to the pyramid, we can climb and get easy 30 points with endgame, which WILL make an alliance want that.

Re: Wheelless Robot?
 

Can you site the rule for this?

Re: Wheelless Robot?
 

I believe that the rule they are citing is <R06> which states...
Emphasis mine.

It's up to interpretation, but would a frame be considered a "traction device"?

Re: Wheelless Robot?
 

More to the point, can a frame damage the carpet?

It's also not terribly difficult to put some plastic on the bottom of a metal frame using countersunk screws or appropriate adhesive.


To answer the original question: If you have designed your robot to play the game in such a way that you do not need to move, I would say that you have satisfied the rules. (I would like to note that I have seen a wheelless robot take the field before, but it's been several years and a slight rule change on the definition of robot since that happened.)

Re: Wheelless Robot?
 

Unless the robot's design is meant to be dragged across the carpet, then under no definition of "traction" does the frame become a traction device. However, if the frame sits there during a match, is pushed and causes the carpet to rip then I think the refs will throw a yellow card.

'No wheels' is a perfectly good way to save weight for a flier. So is the properly-dimensioned 'L' shaped robot -- no bumpers needed on half of the robot, so the weight savings is a big plus. We hadn't thought of such a base until we saw it in Q&A.

Re: Wheelless Robot?
 

Compared to another robot that can climb and can ALSO drive around, (at all), the driving robot can provide a small amount of defense and interference.

Re: Wheelless Robot?
 

You would need to cover all external corners, it would have the same amount of bumpers i believe, correct me if i am wrong, it would look like this... same amount of bumpers.

Re: Wheelless Robot?
 

We were debating bumpers on an relatively L-shaped robot on a different thread: http://www.chiefdelphi.com/forums/sh...d.php?t=110770
Any more interpretation on the 'no bumpers needed' comment with regards to the posts on the thread?

On topic though, my team was (jokingly)thinking of making a cube that sits there and then climbs. It would be interesting, although you'd have to be able to touch your pyramid so you don't get bumped out of position without consequence.

Re: Wheelless Robot?
 

I haven't seen a wheelless robot myself, but there was that infamous match at Midwest where teams elected not to move and start the match in a 30 point scoring configuration:
http://www.chiefdelphi.com/media/photos/27756

Re: Wheelless Robot?
 

I saw a team at Western Michigan in AimHigh that didn't have a drive. Their plan was to just sit and shoot. The bot would basically open up to make it easier for the human player to load. Even tho they didn't quite getting working right I thought it was a cool strategy. Just as a note, to this day it's kinda cool to be able to say that we were once so bad that we lost a match to a robot without wheels.

Re: Wheelless Robot?
 

At some of the shallower events, I'd love to take a robot that can *only* get 10 points a match at pick 24.

Re: Wheelless Robot?
 

Climbing would definitely count as mobility and should result in a legal robot, presuming that you satisfy all other rules.

There is some speculation that the reason for the sentence you quote (in R01) is to keep teams from doing something wildly absurd like claiming that the electronics board is the robot, and that the mobility system (whether for climbing or driving around the field) is just a mechanism that might be added, removed, or swapped in different configurations of the robot as described in R05. ;)

Re: Wheelless Robot?
 

Remember that the FRAME PERIMETER is defined by wrapping a string around the robot in the BUMPER ZONE. (Why the GDC doesn't add one word to that definition, "tightly", is beyond me, but that's what they mean; that's the way it's been interpreted ever since the concept was created.) This means your FRAME PERIMETER extends across the space from one leg of the 'L' to the other leg. 8" on each end of that space must support a bumper - how are you going to do that?

Re: Wheelless Robot?
 

Our team is seriously considering building a pyramid to climb the pyramid

Re: Wheelless Robot?
 

According to this diagram from the game manual:

I think it would be safe to say that you do not need bumpers on the inside corners of an L-shaped robot.

Re: Wheelless Robot?
 

Why wouldn't you? What about that image implies it's okay to not have bumpers on the inside corner?

What that image DOES show is that an L-shaped robot's FRAME PERIMETER would be different than you expect. Concave frame perimeters aren't valid.

Re: Wheelless Robot?
 

I believe he's saying an L shaped robot like the one in the bottom right corner of the figure.

Re: Wheelless Robot?
 

Exactly, the image shows that all corners of the frame perimeter must have bumpers on both sides. It is impossible to have an inside corner to a frame perimeter so there is no sense in talking about them.

Re: Wheelless Robot?
 

Perhaps I'm misunderstanding something here, but isn't it all external frame corners? The 'bot in the bottom right corner does have an inside corner that's un-bumpered?

Re: Wheelless Robot?
 

Look at how the FRAME PERIMETER for the L shaped robot is defined. The black line skips right over the concave section. So, no, you don't need bumpers inside the L, that's true, but the inside of the L isn't the frame perimeter. The team in question seemed to think it was.

Re: Wheelless Robot?
 

This is off of the climbing mechanism ideas thread located here

I think you guys might want to get in touch, it's certainly a viable robot design that could do surprisingly well if it is reliable.

Re: Wheelless Robot?
 

Cool idea... if the robot could climb to the top, deposit four coloured discs into the five point goal, and then hoist another robot into the 30 point zone, you might have something there.

Let's see.... that would be 30+20+30=80 points.

On the other hand, looking at the "robot in three days" machine scoring into the 3 point goal, it might be easier to:

Score 3 discs in the high goal during auto, return and load with four discs, scoring 3 of them into the high goal each trip, completing three such trips, and then complete a ten point climb.

18+27+10= 55 points.

So it looks good for the stationary climber... if they can somehow hoist another, non-climbing, machine into the 30 point zone. Otherwise, I'm not sure the math supports the strategy.

Jason

Re: Wheelless Robot?
 

Shall I bring this back up? :rolleyes:

Re: Wheelless Robot?
 

I don't get the idea of a stationary climber. The reason you would want to make your robot lighter than 120 this year is to climb faster - but obviously a stationary robot can take 90 seconds to climb and it will make absolutely no difference. I think it just makes sense to build a simple, reliable drive base and take the weight penalty.

Re: Wheelless Robot?
 

:confused:
how did they plan to load it?

Re: Wheelless Robot?
 

Aim High was a year where some robots had ridiculous storage capacity. I'd guess a funnel like net at the top that the human player threw into.

Re: Wheelless Robot?
 

If you are going to do this, I would suggest that you shoot three pointers, which are worth six in autonomous, with the discs alloted at the start of the match.

Re: Wheelless Robot?
 

Here are some of the things that a non driving robot can do:

1) Shoot three 3-pointers in autonomous

2) Receive colored disks at pyramid base from partners before climbing by catching the partner shots (or other disk hand off scheme) in a deployed "net-funnel", from which they slide into a dumper, and get dumped in 5-pt. goal

3) Climb to 30 point level and catch disks in a deployed net-funnel, into which both partners can shoot white disk "passes" from the safe feeder zones, and from which these white disks then slide into a shooter that is locked on target for undefendable 3-point goals -- saving on driving for their partners.

4) Lower hoist with hook to lift one or two partners near enough to pyramid rungs for them to get bumped in sequence on way up, or lower horizontal ber for partners to extend hooks up and onto, and then both retract after hook/bar engaged. hanging bots then must touch rungs 1-2-3 in order

Sure, this is a tough list, and deployed net catcher would have to "un-deploy" the net before lowering hook/bar for lifting partner(s), but even doing only some of these can make an effective scoring partner.

The main negative is having zero potential for defensice contribution. The main positive is that once any of these capabilities achieved, they are pretty much undefendable.

-Dick Ledford

Re: Wheelless Robot?
 

Not many teams have gotten ROBOT redefined... :D

1975 in 2007 built a non-mobile robot as well. (Unfolds just after teleop starts)

Re: Wheelless Robot?
 

While I dont recommend this, I would LOVE to see it in action. It'd definitely make my day!

Re: Wheelless Robot?
 

I take issue with some of your points:
Sure you might be able to shoot three 3 pointers in autonomous, maybe feed into an allied robot if you're designed for that. How much weight do you really save though for not moving? Maybe 10-15 lbs for no wheels, gearboxes nor motors.

Funneling shots are a good idea but you will be subservient to allied robots in qualification matches to get them to you. I'm not designing a 'colored disc handoff' device so you're going to have to catch them from me at the top of the tower which I may or may not be designed to do.

I will literally bake a batch of cookies if anyone can pull this off in conjunction with your first point. Remember that you have to actually climb the pyramid, arrive in the proper orientation, then transport discs from wherever your allies shoot them in your body, orient them properly and and shoot them back out -- with the same shooter that was angled at shooting from the ground. By its self it is a lofty objective and a very interesting one. But I think you'll have to choose this or the first one. Raising a net to catch allied colored discs is an absolute must if you choose not to move in the match but remember you are reducing your allied scoring potential if they have to spend time scoring colored for you instead of by themselves for eliminations.

Think about it: If you can drive across the field to pick up four colored discs you can score 20 additional points by yourself. If your ally spends its cycle time picking up those discs and scoring into you when it could be scoring white discs for 12 pts, the net value of that trip is only 8 pts. Sure it's worth it but it isn't the full face value of the discs. This will probably not be a concern in qualification matches where few robots will be able to reliably score colored discs but in eliminations, if I could score colored discs without your help, I wouldn't pick this robot. Interestingly enough, this could lead to a 4th or 5th alliance powering their way to the finals with a robot like this in the lead or first pick.

Remember suspending in 2010? And how it was so difficult because it's hard to predict how other robots will work? Unless you build me a system that can hook onto my belay points it won't work with my robot. Furthermore, I don't think I'd trust another robot to lift us up, especially if it was doing any bumping into anything. Also, unless you occupy a significant amount of space above Level 3 (ie you have to be above the PYRAMID GOAL) then you won't be able to lift a lot of robots into level 3.


That said, I think a robot that does this, if executed properly could win a regional as the second or third seed: You might get screwed over in quals if you have an alliance unable to score into you. Also, if you choose to go for this I'd prioritize the auto shooter over the 'score into me and we'll score in the top goal' shooter. Considering the top sort in seeding behind WLT is auto score, being able to score in auto is a top objective. Also the white disc pyramid scoring is incredibly hard to implement.

Re: Wheelless Robot?
 

This made me laugh. In 2007 I was one of the leaders of the programming team, and one of the members kept pestering us about the code after our first day at a regional. Finally we told him that programming our robot was just too difficult, so instead we made a ramp, and it was as simple as "ka-thunk" (we also mimicked it with a hand gesture).

Everyone on the bus back to the hotel picked up on it, and we all just kept teasing him by saying "ka-thunk". Oh to be immature. :D

Re: Wheelless Robot?
 

Take the weight penalty? As in not being able to play?

Re: Wheelless Robot?
 

As in being harder to climb because your robot is heavier.

Re: Wheelless Robot?
 

By "Weight penalty" I didn't mean "the penalty for being overweight", but rather the drawbacks of having a heavier robot while hanging. A hanging mechanism shouldn't weigh more than 100 pounds, ever.

Re: Wheelless Robot?
 

At the beginning of the match are you allowed to start with 2 or 3 of the colored alliance frisbees?
If so, then you should make a robot that climbs and dumps 2 or 3 of the disks into the 5-point goal at the top of the pyramid in autonomous. If you could do that, you could score 50 or 60 points consistently! I've never thought of that idea before, but that would be very impressive!

Re: Wheelless Robot?
 

The colored discs start behind the alliance station.

Re: Wheelless Robot?
 

Only White discs are allowed to be pre-loaded, so this is impossible.

Re: Wheelless Robot?
 

There is no legal way to score in the pyramid goal in autonomous. Please read the manual - you will see under the Game section that there is no point value for the Pyramid goal in autonomous, and you will also see that you have no access to the colored disks, nor can you cross the center line of the field fully anyway.

Re: Wheelless Robot?
 

Even if it was legal to pre-load colored disks, why would wasting the 12-18 point potential of autonomous scoring in the 3-pt goal, with a consistent, pre-aligned shooter, be sacrificed for lesser 10-15 points value of a pyramid climb & dump score later in the game?


-Dick Ledford

Re: Wheelless Robot?
 

He was saying that the robot would shoot, presumably from the floor, in autonomous mode to get a fictional 10 points per frisbee.

Re: Wheelless Robot?
 

sorry for bringing this up, but I haven't been that involved in this years game and I haven't gotten this straight: what is the difference between regular and colored disks?

Re: Wheelless Robot?
 

Colored disks start in the human player's possession and are the only discs that can be scored in the Pyramid Goal. They can also be scored like regular discs. White discs start both on the field and in the human player's possession and can be scored in any other goal.

Re: Wheelless Robot?
 

Now I get it. In addition to ignoring the no pre-load of colored disks, he was then also DOUBLING their value to 10 PTS. when they would be dumped into the pyramid goal, after having completed the autonomous climb in a mere sub-15 seconds.

Pretty good imagination!!

-Dick Ledford

Re: Wheelless Robot?
 

The correct colored disc also must be placed in the pyramid. If you are blue you must use blue discs for your pyramid, and if you are red you must use red discs for your pyramid.

Re: Wheelless Robot?
 

Colored discs scored in normal goals are indeed valid.

Re: Wheelless Robot?
 

Valid in this case meaning they would be scored as any other white disc. IE A red disc in the three point high goal is worth 3 pts.

Re: Wheelless Robot?
 

Wheel-less robots I can see coming from adventurous rookie/near rookie teams.

Our teams robot weighed in at 84 lbs with a 4 CIM drive and a 30 pt climb mechanism.
The weight does not include our arm. We plan to get a definite 50 pts a game. Plus some possible 1 pts.

Re: Wheelless Robot?
 

Autonomous and a 10pt hang can easily offset 30pt no to mention scoring through out the match. Without a drive train you cant even be a defensive bot. Im not sure thats the right route but we will find out soon enough.:rolleyes:

Re: Wheelless Robot?
 

We are not talking about being a defensive bot. we are talking about having a shooter during autonomous and then climbing all the way to the 3rd level which would get us at least 30 points.

Re: Wheelless Robot?
 

A robot that does not have a wheels can score at 18 points in autonomous and 30 points by climbing. That is a substantial amount of points for the other alliance to recoup.

Re: Wheelless Robot?
 

Yes, it is possible to have success building a robot without wheels. 997 reached the semis of the 2013 Autodesk Oregon Regional using a robot without wheels. They scored 30 points in all 14 of their matches.

Re: Wheelless Robot?
 

3055 climbed and had no wheels. So far they have, IMO, one of the most unique climbing methods I've seen. They use magnets as a stabilizer and these "knuckles" that nest in the corner bracket to climb. I think they only have 1 motor,a CIM, on their whole robot.

Re: Wheelless Robot?
 

OK, returning to this thread with an update following the Midwest Regional, where we were the only wheelless robot, as well as the tallest robot @ 72"
(PICs to follow). Making it to only one practice match on Thr., we had effectively no real practice by the time of our first qualifying match on Fri., so we did not perform very well until the final few matches.
Even so, we ended up being captains of the 8th seed alliance for eliminations.

Though our original design goal was to be an wheelless outside corner climber for a 30 point climb, the team could not handle the compound angle design requirements (no CAD) that the frame and mechanism mounting demanded.

After Losing a week to finals, a week to building a badly executed half-pyramid out of conduit, and a week to no real progress with the corner climber concept --- we finally bailed on the plan and switched to an inside face climber, going only for 20 points.

We already had built a lightweight, tiny 2 wheel linear rail shooter capable of hitting 3-point shots in autonomous, and working consistently enough that we expected to get our 18 points on auto shooting. So, with 20 more from the climb, we felt that with a reliable 38 points we could still make it into the elimination round,

Our climb concept was to have our bot sit in middle of far side of pyramid (from goals) with hooks on lower rail. We made dual vertical linear sliders with vertical 80/20 framing and window motors turning 5/8" OD shafts to wind high tech cord for lifting, Cords pulled down on crossbars, each with a pair of hooks pointing outward mounted to them, and the crossbars slid down between the two pairs of columns.

The the slider travel of the shorter column pair could get us up as high as 13 inches, and the longer column pair, ~11" closer to center of pyramid, could lift until the cross bar nearly hit the winder shaft mounted close to the base plate of our wheeless bot -- about 42" of travel

The short column pair was set near center of the the bot so as we came off the ground onto the lower hook pair we stayed balanced. Our shooter was mounted to the top ends of the shorter column pair on overlapping extension legs that extended the shooter up higher. The hook slider bar for the tall column pair was positioned so both its hooks would start out above and nearly engaged to the 2nd level rail, but not until the lower hooks got us an inch off the ground.

Once off the ground, the upper hooks were engaged with the second level rail and we planned to elevate with both hook crossbars pulling together, to keep us from tipping over much for the first foot or so.

Once the cross bar pulling down the lower hooks reached its lower travel limit, where it would start to capture the lower rail against the frame if it did not stop, the upper hooks took over. At this point our excess weight (battery, electronics, etc.) sticking out of the pyramid was meant to cause the robot to swing away from the lower rail as the upper hooks continued to lift and the lower hooks disengaged, allowing the upper hooks to drag the bot past the lower rail.

Getting the bumper frame, base plate, winders, columns, sliders, and shooter module built and in the bag by deadline was all we were able to do with the late start. We would have to complete the build in the pits, but we still planned to make a practice bot to verify functionality before competition.

We barely finished our practice bot in time to do the most rudimentary test and confirm that it looked like the balancing could work well enough for 20 points, but it was not a perfect mockup at all.

In the pits on Thr. we were able to complete our bag bot assembly rather efficiently, but our electronics were giving us fits, and we could only get one shooter shooter motor to run at a time, not both. We finally confirmed that a missing firmware update was needed, and it would have to be installed in Fri.
We really did not get to do any climb testing until our first practice match in late PM on Thr., and we found out that our upper hooks were swinging too far away from the 2nd level rail before we could clear the ground enough to engage.

So by the time of the 1st Fri. match we had only just got our shooter running with both motors, and had not practiced aiming at all. We also had modified our column angles to ensure upper hooks remained able to engage the 2nd level rail

There were several seconds of wild pendulum swing as the lower hooks disengaged and the unbalanced weight tipped the base of the robot down and toward the center of the pyramid. This always gave the crowd a thrill.

As we continued to pull the upper hooks toward the robot base, the robot kept tipping over more from the weight of the shooter above the 2nd rail going progressively further away from the 2nd rail as the heavier base got closer to the 2nd rail. With a couple increments of adding upper ballast (done in the pits), we finally tuned the the weight distribution so that we balanced with our initial vertical now oriented horizontal, and only 29" of our robot length hanging down below the 2nd level rail,

It took missing the twenty points by 2" then 1" then 1/2" over several matches before we finally got things tuned up enough to score our first 20 point climb. Meanwhile we were getting 10 point climbs every match and finally getting two 3-point autonomous scores in one match. Plus our human shooter was coming through with some amazing shots to even win one close match.

We steadily moved up in the standings until on Sat. at the end of qualifying we were in the low teens. As the alliance picking process started pairing up the top 8 seeds, we ended up heading the 8th seed alliance.

While our alliance with Team 1091, and Team 2704 was not quite enough to match the first seed's alliance in the quarter final, we thank our partners for working hard with us for a respectable performance in our two matches.

In hindsight, I still don't quite see how a wheelless bot that averaged only around 15 points per qualifying round could end up heading the 8th alliance, but this is how things turned out. Needless to say many of the team members who were grumpy about the no wheels design ( no wheels means no fun), quickly forgot all that when they saw how few bots could climb past 10 points, and how low the match scoring was in the qualifying rounds.

So, to address the concerns of the OP in this thread, the lesson our team learned is that, at least in this year's competition, a wheelless robot, that remains protected contacting the pyramid has a lot of things going for it. It takes on little damage. It is less complicated to maintain and troubleshoot. It is easier to produce consistent scores in every single match, which in the end is what allowed us to do so well. We weren't expecting to make it all the way to the final match, but we surprised ourselves at how well we ended up doing.

So in this fourth year of our FRC program, we managed for the first time make it to a practice match, to make it to every qualifying match, to score in autonomous, and to make it to the elimination round without having to be picked. Pretty amazing results for a wheelless robot.

Once again, thanks to our alliance partners, Team 1091 and Team 2704, for a strong effort at trying to upset the top dog alliance. Wish we could have offered more firepower and defense, but we still had a great time competing.

-Dick Ledford

Re: Wheelless Robot?
 

Our alliance partner was NOT 1001 and was actually 1091 Oriole Assault

Re: Wheelless Robot?
 

Yes, don't know how I typed it wrong twice? Thanks for the correction though (fixed now).
-Dick Ledford

Re: Wheelless Robot?
 

A Robot with no wheels:
http://www.youtube.com/watch?v=wkrQI..._Vw& index=25

Re: Wheelless Robot?
 

This is my team's robot climbing to 20 without wheels.

http://www.ustream.tv/recorded/30977425

Re: Wheelless Robot? Team 3135 20-point hang
 

Here is a PIC of Team 3135 in final position for a 20-point hang



A bottom view from in the pits practice area:

Re: Wheelless Robot?
 

Team 2634 had a wheeless, pure climbing robot at the Greater Toronto West Regional. Their climbing mechanism was a hook on a lead screw to climb, along with two passive hooks to hang with. Their lead screw mast was articulated, so it could reach the bars. They would typically start their climb in autonomous, and achieved many 20 point climbs, with a few 30 point climbs over the weekend.

Here is a video of their final qualification match, where they attain a 30 point climb. They start the match inside the blue pyramid: http://www.watchfirstnow.com/archive3.php?id=62996910

Re: Wheelless Robot?
 

Dick,
I have watched you for a few years now and I have to say this year you nailed it. I am very proud of you. You came up with a unique solution and for the most part it worked as designed. Congratulations!

Re: Wheelless Robot?
 

ROFL. We wouldn't know anyone that would built something that absurd ... would we? :eek: