Re: pic: Team 148 - Robowranglers 2010 - Armadillo
 

I mean to say that the rollers pinch the ball just enough to hold it and squeeze it in...Nothing physically under the ball. Sorry bout my wording.

Re: pic: Team 148 - Robowranglers 2010 - Armadillo
 

Now that, is a robot.

My god is that ever a robot.

That is everything I dreamed of and more, for a championship winning robot.

I want one!

-Nick

Re: pic: Team 148 - Robowranglers 2010 - Armadillo
 

Good question -- after some extra viewing, especially with the side angle from the tunnel, it appears that the tractions are inline with the omnis. If you think about it, having only 4 wheels on the ground with the outer four corners being the contact points would mean the bot couldn't turn exceptionally well. Yet that is a very agile robot. Thus I'd say it's 8 on the floor. It's practically ingenious, and I'm very curious to know how the module are actuated. My initial thoughts would be a spring suspension that's pulled up via rope that's attached to a window motor. The modules pivot cocentric to the omnis, thus the bumper zone planes never change. I think the rope would stretch over time though. Hmm.

Ingenious indeed.

Re: pic: Team 148 - Robowranglers 2010 - Armadillo
 

Wow, that IS a sticky ball magnet! Hopefully not too sticky

Re: pic: Team 148 - Robowranglers 2010 - Armadillo
 

so that means they are carrying then, right?

Re: pic: Team 148 - Robowranglers 2010 - Armadillo
 

I don't know, I'm not a referee

Re: pic: Team 148 - Robowranglers 2010 - Armadillo
 

Uhm, isn't that bad?

-Nick

Re: pic: Team 148 - Robowranglers 2010 - Armadillo
 

ya, carrying is illegal

Re: pic: Team 148 - Robowranglers 2010 - Armadillo
 

That's definitely not how they hold the ball normally. It only occurs when you go too far into the goal. I'm sure they already know they can't do that and are practicing to make sure they never do.

Re: pic: Team 148 - Robowranglers 2010 - Armadillo
 

But is it carrying the ball when the bot is driving around on the flat parts of the playing surface? Technically, the ball could still be touching the ground when the robot is on level ground. But, if the situation in the above picture happens, does that even matter?

I apologize if this has already been covered in an update/Q&A. I'm currently abroad in Thailand and unable to build this year. :(

Re: pic: Team 148 - Robowranglers 2010 - Armadillo
 

To me, what is most impressive to me is this --

There are many teams that will build their robot, ship it, and compete with it in some events and just fix things when they break. They would be 'satisfied' and take a rest.

Knowing 148 and their mentors, they will take the "design is an iterative process" philosophy and continue to update, revise, modify and improve this machine all they way through the Championships and the machine in April will be much different from the machine that goes into a crate on February 23rd. They will see what other teams have done, they will see what works and what does not, they will see how this game plays out on the field and make the adjustments and maybe make major changes.

That is how great teams do it, and that is how great companies do it.

If you have not, read JVNs design paper, read it.

And once again, great job 148!

Re: pic: Team 148 - Robowranglers 2010 - Armadillo
 

I'm not a ref either, but I do know that the GDC has ruled that if the ball is possessed and comes off the ground, it is carrying, period. Now, whether or not the refs catch it is another matter.

Still, with 65 lbs and a couple weeks to work with, I'm sure 148 will come up with something to keep the ball down on the ground.

Re: pic: Team 148 - Robowranglers 2010 - Armadillo
 

Read it, and live it, if you can. It takes a LOT of work, motivation, and leadership skills to keep improving the design continuously! Kudos to 148

Make that twice again :) Awesome machine

Re: pic: Team 148 - Robowranglers 2010 - Armadillo
 

The situation above isn't going to happen. It's not a design flaw. It's an issue of the drivers letting go of the ball before going too far into the goal.

Re: pic: Team 148 - Robowranglers 2010 - Armadillo
 

If the drivers have to let go of the ball, then they were holding onto it, which is what CARRYING is all about?

It looks a bit iffy to us mere mortals.

Re: pic: Team 148 - Robowranglers 2010 - Armadillo
 

Not saying I know how their ball magnet works, but ...

If they reverse it and make the tip of the roller go the same speed of the drive train x2 then it'd be impossible for them to carry regardless of what the drivers do.

Re: pic: Team 148 - Robowranglers 2010 - Armadillo
 

If you look at 1:54 on the video, you can see a yellow upper roller (if it is a roller) and a black lower roller. You can also see them holding the ball at 2:01. Hope this can help shed some light on the subject.

I love this robot, it's genius. 148 always inspires a little jealousy in me each year.

Re: pic: Team 148 - Robowranglers 2010 - Armadillo
 

I think the best "soccer analogy" would be if you pinched the ball between your feet, you'd have to let go before jumping if you wanted the ball to stay on the ground for whatever reason.

Re: pic: Team 148 - Robowranglers 2010 - Armadillo
 

I love the hanging. What an amazing looking and capable robot.

Re: pic: Team 148 - Robowranglers 2010 - Armadillo
 

We just turn off the magnet now before going up the goal ramp...
That won't happen in competition.

-John

Re: pic: Team 148 - Robowranglers 2010 - Armadillo
 

I look forward to seeing this in Dallas... impressive.

Re: pic: Team 148 - Robowranglers 2010 - Armadillo
 

With regards to the ball magnet, think of it this way:

If the normal force between the ball and the floor is less than the normal force generated between the ball and the "magnets", then the ball will stay possessed by the robot. This doesn't mean the normal force between the ball and the floor is zero.

The instance you see in the video near the goal was an implementation issue that has already been resolved. The ball will always be touching the floor when the magnet is on.

I can tell you this: we (148 + 217) created the ball magnet concept using only 9th grade geometry and 11th grade physics (1st semester).

Re: pic: Team 148 - Robowranglers 2010 - Armadillo
 

Hey hey, who you callin amateurs? ;) :D But seriously, this is why their robot is good. It all comes down to material removal. The secret is in the laser. We spend 2 minutes to drill a hole. They spend 20 seconds to CAD it and laser cut it. We spend many minutes milling solid, they spend a few burning through sheet. Multiply that by hundreds of parts, and you get the idea.They can do more in less time, and this is why it's done and good. Quite smart. This robot makes me feel like for 9 years I have not been working hard enough (or perhaps not smart enough). Great job 148!

All I can say is, if this robot ever comes head to head with 254, the match will be one for the books.

Re: pic: Team 148 - Robowranglers 2010 - Armadillo
 

Paul,

I think everyone is just a little jealous of the 148/217 "ball magnet" skills.

I thought something like this would work but we never got around to prototyping it... boy do I wish we did now.

Re: pic: Team 148 - Robowranglers 2010 - Armadillo
 

Well I was referring to the team 100 students... It took them a week last year to cut a single keyway :( :o And that’s not for lack of trying! They worked on it every day! :eek:

Re: pic: Team 148 - Robowranglers 2010 - Armadillo
 

All I know is I went to Home Depot and the guy there said they did't sell ball magnets. Maybe only the Texas and Michigan stores carry those.

Re: pic: Team 148 - Robowranglers 2010 - Armadillo
 

I think 1726 found some in Arizona too.

Re: pic: Team 148 - Robowranglers 2010 - Armadillo
 

I’m progressing well this year through what I think of as the FRC equivalent of the Kübler-Ross model (commonly known as the five stages of grief). I imagine that there are many other folks going through this as well and hopefully we won’t dwell too much more on the negative aspects. Anyways, here’s where I am in my process:

First came “awe”. What an awesome robot! Function AND form nicely wrapped together! Great video! What an awesome TEAM!

Next came “envy”. Wish we could create a robot like that. Wish we had such an established and well-grounded design process. Wish we had access to such a great world-class production facility. Wish I could be part of a team like that.

Followed quickly by “depression”. How can we compete with that? Am I lacking as a mentor since we aren’t capable of creating robots like? Why even try?

Hopefully I’m solidly into the “acceptance” phase now. Regardless of how good any team is, I can still reach out to my team and inspire them in their pursuit of STEM fields. We can still play Breakaway to the best of our abilities. And since FRC is played with alliances of three teams, any robot that can drive can contribute to their alliance’s success. Great strategy can often counterbalance exceptional single robot performance. So how do we win with what we have? Quite frankly we’re happy to have been able to produce a robot at all with all the snow outages…

[tangent] What I particularly like about 148’s design is the potential ability to score 3 in autonomous and 2 in the end game. I envision eliminations to be defensive struggles with limited scoring, so capitalizing on these “guaranteed” points is vital. I’ve long admired 217’s and 1114’s (among others) ability to integrate robot design with overall game strategy to maximize the probability of winning.[\tangent]

Eventually I’m sure I’ll move into “inspired”. Particularly when teams like 148 are there to help us by providing white papers, robot design, experience, insight, etc.

Re: pic: Team 148 - Robowranglers 2010 - Armadillo
 

I can assure you the reason the ball magnet that 148, 217, and few others teams have works so well not some black magic, but due to the fact that 148 is amazing at prototyping, and spent hundreds of man-hours on "system 5". They deserve all the success (and defense) they are bound to get this year, 10x over.

Re: pic: Team 148 - Robowranglers 2010 - Armadillo
 

I totally agree Tom. 148 is one of the few teams that inspires me every year. They truly live by the phrase "design is an iterative process." All teams in FIRST should strive to live by this and 148 is just a prime example.

I just happened to have a major facepalm moment when I saw that roller. Just goes to show, you can never prototype too much.


Man do I wish our magnet worked this well.

Re: pic: Team 148 - Robowranglers 2010 - Armadillo
 

If i could spend just one build season with this amazing team as a mentor, I would be a happy happy alumni of the JVN school of innovation, inspiration, and design

Re: pic: Team 148 - Robowranglers 2010 - Armadillo
 

Nope, not a MI product...Home Depot doesn't have any (or #25 masterlinks, for that matter). Must be a Texas product.


It's really cool to know that this is something that I could do, with a little thinking and application of my physics homework. Note to self for next year, apply physics rather than "well, this SEEMS like it would work." 1-sentence inspiration, right there.

Again, way to go 148 (and 217). Seriously cool stuff, srs bizniz, kick-butt, whatever way you choose to describe it.

Re: pic: Team 148 - Robowranglers 2010 - Armadillo
 

We're getting too much credit for the Ball Magnet. The Ball Magnet design is a 100% collaboration between 148 and 217. The Thunderchicken Prototype and Design teams are as good or better than their 148 counter-parts.

Every compliment that is paid to 148 should be echoed 10 times over to our counterparts up north. Years later, I still love the Thunderchickens!

-John

Re: pic: Team 148 - Robowranglers 2010 - Armadillo
 

Something tells me we need to fear 148/217 in Atlanta, and 1114 at all of our competitions... not that I wasnt ALREADY expecting that.

Re: pic: Team 148 - Robowranglers 2010 - Armadillo
 

Hey everyone, you don't have to try to beat teams like 148 and 217 (and teams like 67, 1114, 45, etc. - whatever they come up with). All you have to do is be good enough that they want you on their alliance.

You've seen this; now think of what can you do to complement them, not try to oppose them. And give a few compliments along the line too.

Re: pic: Team 148 - Robowranglers 2010 - Armadillo
 

aww but thats the fun part :p

Re: pic: Team 148 - Robowranglers 2010 - Armadillo
 

Shh, you're spoiling my backup plan. :P

Every set of fingers needs a thumb...

Re: pic: Team 148 - Robowranglers 2010 - Armadillo
 

Agree. If you can't beat them, join them!

This year's tournament structure (with the weird seeding points none of us are used to), could yield a very different outcome than we're all used to.

It means that someone different could end up on top of the standings, and pick one of these powerhouses (148,217,1114,910,67,45,2056,etc) and upset their normal balance (for instance, the 1114/2056 perennial duo).

Re: pic: Team 148 - Robowranglers 2010 - Armadillo
 

I think I did the exact same thing!!

But then I had thought's similar to Travis's
And Finally I went to look at the "older" robots from 148 & 217:
http://www.robowranglers.com/history/
http://www.thunderchickens.org/ (click on robots)

And realized that looking back to their first few years, they had silly little aluminum bar and PVC robots like the rest of us... 148 has been building & learning since 1992, 217 has been building & learning since 1999, thats 29 years of experience combined!! Why do I mention this? because they are doing what we all should... CONSTANTLY strive to be better every year. You can see it in the progression of their robots, and they came up with the idea of sharing that experience across teams. You can do infinitely better if you dont try to take on all of the work yourself and if you learn from other people's successes and mistakes as well as your own. I'm not saying all teams should co-operate, but for any of you that get that hit of jealousy that I did, just sit back and realize that we ALL can do this too... if we just strive to be better every year. Don't have the resources? GO FIND THEM!! If 1114 can get parts made in Texas, why cant an MD team get parts from CA?? Find resources, find really good engineering mentors, find money, constantly try to do better and do more, have patience, PRACTICE, and you CAN be 148 or 217 :) Use your jealousy as inspiration if you must!

But before you get stuck in the depression stage realize we are all inspiring kids... I bet those kids that took forever to mill a keyway will remember that for the rest of their lives, and are no less inspired. They may not have gained the depth or breadth of experience that a 148 student does, but our point is to get them to WANT to... to head off to college wanting to be THAT good.

Congrats to 148 & 217 for setting a really high bar for the rest of us :)

Re: pic: Team 148 - Robowranglers 2010 - Armadillo
 

Quick question Paul.. I was looking at the dates in which 148 and 217 are competing. Does this mean that for 5 straight weeks your going to be right in the middle of inferno of this game?

Re: pic: Team 148 - Robowranglers 2010 - Armadillo
 

There's another Copioli behind the glass this year.

Re: pic: Team 148 - Robowranglers 2010 - Armadillo
 

Can anyone from 148 get this up on Google video or put it on your site directly? Youtube is blocked from our school.

Re: pic: Team 148 - Robowranglers 2010 - Armadillo
 

Paul has historically joined us Canadians in Wk 4 at Waterloo Regional... I wonder if we're going to see him there paired up with Karthik as our emcees.

Delicate Balance of forces
 

Pinching a 9 inch soccer ball at two points within the allowable 2/3 portion is very tricky indeed. Just holding a soccer ball with two tacky parallel cylinders is not easy. We found balancing the "dynamic" forces is very difficult (air pressure in the ball, static and rolling friction, etc.). Although I do not have a PhD in Physics, I am convinced that simple force diagrams will not capture all the variables - especially when the robot is moving. Experimental confirmation is key here.

During our prototyping, we could not find that delicate (favorable) force balance required for an approach like yours. It appears that you found the sweet spot. Congratulations.
:) -- to all other teams, "there is another". Looking forward the NJ.

-------

Re: pic: Team 148 - Robowranglers 2010 - Armadillo
 

Very nice robot. I am glad I will get to see it at the Dallas Regional.

Seeing that drive train brings back memories from Rack n' Roll.

Re: pic: Team 148 - Robowranglers 2010 - Armadillo
 

Wow...just, wow...

You just put a good portion of a rookie team into shock and awe. I'm really impressed. A killer robot and a killer drive team, and that hanging mechanism is brilliant. The amount of work and teamwork this took must be astounding. I can't wait to see this in action, either over webcast or if we qualify for and go to Atlanta. Wonder how many teams are already making strategies against you guys. ;)

Re: pic: Team 148 - Robowranglers 2010 - Armadillo
 

Yep. My brother Mike will be behind the glass for 217 this year. He has coached at IRI for the last two years so he has a lot of experience behind the glass. 217 historically practices every day after ship with the practice bot (think like a sports team here) so it was not fair to this year's drive team to not have that practice time with the actual drive coach. Besides, Mike is a better coach than I am as he keeps his cool much, much better than I do.


I will be at FLR with 217 on week 1, Cass Tech with 217 week 2, Dallas with 148 week 3, week 4 off, and week 5 with 148 in Dallas. I am really upset that Michigan State Championship is not week 6 this year.

Not this year. I have this little thing called the VEX Robotics Competition that we have in 20 countries all over the world. Week 4 I have to be in New Zealand (yep, the country) for their country's championship. During week 4 this year I will miss my first team 217 match in 11 years. It will be a very somber day for me...

Re: pic: Team 148 - Robowranglers 2010 - Armadillo
 

looks like some hefty machining went into the arm joint, no doubt donated by the thunder chickens? it looks similar to the hinge on their 2008 robot.
as for the drivetrain, the pnumatics dropping down the middle "strafe wheel" as you pull up your traction wheels gives this robot some fierce adaptability. don't expect to be able to pin 148 anyway similar to lone star 2009.
yet again, the robowranglers seem to make use of almost every motor in the kit, while still maintaining an elegant design. good work.

Re: pic: Team 148 - Robowranglers 2010 - Armadillo
 

Possibly the wost news of my day... We will miss your play by play's!

Re: pic: Team 148 - Robowranglers 2010 - Armadillo
 

That's too bad Paul, I've enjoyed giving you ideas to 'spice' up the announcing at Waterloo the last couple years. You and Karthik, plus some webcast input, was a dangerously fun combination. Not even sure yet if I'll be getting up to Waterloo for long this year.

Re: pic: Team 148 - Robowranglers 2010 - Armadillo
 

Great work Robowranglers. The DiscoBots are looking forward to playing 148 in Lone Star !

I'm still a bit confused as what drops down and how. Do you only raise the strafe wheel when going up the ramp ? How do the traction wheels move up and down ?

Re: pic: Team 148 - Robowranglers 2010 - Armadillo
 

If you pause the video, there seems to be a pivot in the center. I'm guessing it all actuates on one joint.

Re: pic: Team 148 - Robowranglers 2010 - Armadillo
 

You need keen eyes to watch a Robowranglers video.

It looks more like each of four wheel pods are actuated individually by a pneumatic cylinder. See this picture, which I assume to be a Nonadrive practice chassis that was figured out sometime before build season.



Also, I scanned this years video for small hidden photos of 1114 or 217 to no avail. The build pictures do show how many crazy prototypes went into this design.

Re: pic: Team 148 - Robowranglers 2010 - Armadillo
 

Thanks Travis. Sometimes I, and I'm sure many others, need reminders like this to keep our heads on straight.

148 and the rest of team IFI and their success has driven our collaborative partners in EWCP to reach a higher level to compete against formidable teams. EWCP wants to be these teams (and later on, beat them :rolleyes: :p if possible).

Its very cliche, but you guys really don't know how much you inspire me to better every team I come in contact with, including my own. This is my heartfelt thank you, for just being you and doing the things you do.

Re: pic: Team 148 - Robowranglers 2010 - Armadillo
 

pssst week 5 = Lone Star, Paul, Lone Star. On your way back from New Zealand, stop by Austin and we'll point you in the right direction. :)

Travel safe. It's wonderful to have you here in Texas!

Jane

Re: pic: Team 148 - Robowranglers 2010 - Armadillo
 

I hope we see you guys in Atlanta :D

Re: pic: Team 148 - Robowranglers 2010 - Armadillo
 

Numbering the bottom was a nice touch.

Re: pic: Team 148 - Robowranglers 2010 - Armadillo
 

The girl in the back is not wearing safety goggles. not only is this a detriment to her own health but this sets a bad example to the many visitors to chiefdelphi.

Remember, Safety is for squares. Squares made up of the 4 equally important virtues of safety which include: Proper training, PROTECTION, proper attire, and common sense.
Please, nbext time you create a video such as this, please remember to wear your safety goggles. as a mentor of my own team, i often try and make a big deal of this because i have seen the horrors of machine shop accidents gone bad.
Sorry for the rant and good luck the rest of the season!

Re: pic: Team 148 - Robowranglers 2010 - Armadillo
 

What is the mechanism that is locking onto the bar? How does it work?

Re: pic: Team 148 - Robowranglers 2010 - Armadillo
 

It is called a gate latch and we took the idea from the 217 1999 robot. Yes, we actually used something from our rookie year.

Re: pic: Team 148 - Robowranglers 2010 - Armadillo
 

Thats interesting. So the weight of the robot is holding the whole system in place. Awesome design 217 and 148. Hope we can compete with both of the teams at the championships!

Re: pic: Team 148 - Robowranglers 2010 - Armadillo
 

Now that I've watched this video five or more times, I feel like I can make an educated comment on "Armadillo" and the Team 148/217 (And whatever other teams are in this whole team IFI) Collaboration.

As I saw robots being posted up on CD this year, I kept thinking to myself "None of these robots have the capability to dominate a match". I began to think to myself that there would be no way any single machine could dominate a match this year, similar to lunacy.

Then I saw this video. I realized that Breakaway could be dominated. I also realized a lot of other things, things that I thought I already knew. I noticed that Team 148 (and presumably 217) do substantial amount of prototyping before they even start to design robots. This is where we've failed every year. We look at the game a design a machine from day one and we always are trying to finish as early as possible. I never thought to slow things down and prototype and research and just play around with some concepts. Maybe next year we'll have to take this new approach.

Regardless, Armadillo is surely one hell of a machine.

Re: pic: Team 148 - Robowranglers 2010 - Armadillo
 

Just wanted to say that I saw your video, and your robot looks awesome. I love the kicking and hanging mechanism. Great job!

Re: pic: Team 148 - Robowranglers 2010 - Armadillo
 

Team 148 has clearly spent a lot of time tailoring and streamlining their engineering process which enables them to spend more time in the early design steps. My occupational experience (and research in defect analysis) tells me that dedicating more time up front provides the biggest return on their labor investment. In order to generate this time, they have become extremely efficient in modeling, production, integration, and to some extent testing.

The beauty of teams like 148 is that they tell you exactly how they achieve their success (see JVN's engineering design whitepaper, full CAD models of 2008/2009 robots, and the "How it is Made" video among other resources they have produced). I think the trouble many teams have (mine included) is that the engineering process is applied ad hoc and even if following a proven process there is no analysis of the process itself for where to eliminate waste and optimize the implementation of each step. For example, if it takes to long to integrate subcomponents try modeling more. If it takes to long to model, train more students in the off season and become really proficient. I think without an efficient engineering process, the only hope teams have of being reliably competitive is to (1) out work the competition (probably not practical and it is a hard way to go even if it was) or (2) out think the competition (unreliable). Team 148 is demonstrating what engineering should be all about and is showing that it works!

Re: pic: Team 148 - Robowranglers 2010 - Armadillo
 

BINGO... ie DO NOT TRY THIS AT HOME!!! If any regular team spent 3 weeks prototyping, they would be in a world of hurt because their parts would never get finished in time to even build a robot. I know this because in 2006 1511 spent that 3 weeks prototyping, and finally abandoned all prototypes and went with a concept we figured would work, no design, we just built it... fortunately we survived, but we most certainly did NOT come out with an elegant machine, and did not have enough test or programming time. Dmentor hit it on the head, its that they have trained their students and team so well on design, and have great manufacturing support and capability, and THAT allows them to prototype for that long to come up with the best solutions. Until you get to that level of engineering process, in my mind you CANNOT spend 3 weeks prototyping or you will shoot yourself in the foot.

I would still suggesting picking 1 design right up front and racing to finish it as fast as you can so you have debug and programming time at the end, unless you have an insanely well trained and well oiled team (hint use preseason wisely). My bet is that once they pick their designs, teams like 148 & 217 can crank out full designs in 4-5 days, manufacture in 3-4 days, and then still have time to test. 1511's best robot design was probably 2008, and that took us 4 weeks of CAD design, because we are NOT proficient enough. It worked for us because we picked the design by day 2, designed for 4 weeks, had parts built along the way and were left with about a week to debug & program, but there is no way we had time for 3 weeks of prototyping.

Maybe John or Paul could post a sample schedule that they follow... :)

Re: pic: Team 148 - Robowranglers 2010 - Armadillo
 

They did, it is in the Design Process paper.

Re: pic: Team 148 - Robowranglers 2010 - Armadillo
 

Dear god. Im actually fearing for the well-being of my robots life right now.

Then again I should expect nothing less from the team who made that absolute beast of a robot that we ocasionally had to compete with in last years Dallas regional. I look forward to seeing teh mayhem that your team will cause when we meet again in dallas :).

Re: pic: Team 148 - Robowranglers 2010 - Armadillo
 

Whoa....our bot is primitive in comparision. We're concentrating on keeping things simple, running consistently, and being able to move/support our alliance teams this year by good defence, going through the tunnel/over the hump, and making those "garbarge goals" whenever possible. In comparison to y'all's bot...we're looking pretty lame.

See you in Dallas! We're from Summit International Prep-Our bot's name is GAGABot! Hope it doesn't turn into gaga-me-bot! :eek:

Re: pic: Team 148 - Robowranglers 2010 - Armadillo
 

so epic. good job 148!!

Re: pic: Team 148 - Robowranglers 2010 - Armadillo
 

that bot is so awesome... i just can't believe how awesome that robot is... it is just amazing

Re: pic: Team 148 - Robowranglers 2010 - Armadillo
 

This is great. I'm loving the video. What I fail to understand is how can all of this be done in 6 weeks? Students have school to attend, mentors have jobs to work. The drive base alone looks like it would take a team at least 6 weeks. And they were probably done by at least week 4 so they could debug and practice. I just don't understand how there are enough hours in the day to make a machine that is this amazing. This is truly amazing. You all better do well now that you have such a neat bot.

Re: pic: Team 148 - Robowranglers 2010 - Armadillo
 

calling winner of nationals right now, great job guys, best robot I have seen by far

Re: pic: Team 148 - Robowranglers 2010 - Armadillo
 

Totally Awesome!

Re: pic: Team 148 - Robowranglers 2010 - Armadillo
 

Seconded. We spent 3 weeks prototyping last year (some things were designed during the process, though), and we barely got a somewhat-working robot in the bag. Even then, we still made a lot of tweaks - particularly in the code - at Kettering, which was our first competition. We had no practice time before bag, which, while unfortunately normal for us, is definitely something that would hurt a lot of teams. We managed to catch up with ourselves at Detroit, but Kettering was not a fun experience. Don't do it, folks!

Re: pic: Team 148 - Robowranglers 2010 - Armadillo
 

I just checked to see if IFI's website have the kicker in stock...

... they don't. =(

Re: pic: Team 148 - Robowranglers 2010 - Armadillo
 

Yeah, we got the last one. :D j/k

Re: pic: Team 148 - Robowranglers 2010 - Armadillo
 

So I've had a couple days to salvate over this robot/piece of art, but I do have a couple questions.

First off, what's the purpose of the pole that extends beyond the hanging mechanism? Is that to aid with alignment?


Secondly, what prompted you to go with the dropping center omni wheel set-up, instead of just having the four articulating drive pods with mecanum wheels instead of omni (similar to what is shown on pg.4 of this paper)?
The only advantages that's obvious to me of your configuration is it's likely cheaper than buying/manufacturing mecanum wheels and you save some weight and money by using one fewer gearbox (as you can drive both sides of the robot together, but also have to add another one in for the center omni). But otherwise it seems like you're using an additional motor and point of articulation for no real benefit over a similar concept using mecanum wheels.
Also, are you using any sort of closed-loop control to try and account for uneven forces between the forward/reverse (where you have four motors operating) and lateral directions (where you only have one)?


Overall, it's obviously an absolutely gorgeous machine that I certainly hope I get the opportunity to examine at greater detail.

Re: pic: Team 148 - Robowranglers 2010 - Armadillo
 

That was my thought - it also adds to the aggressive appearance of the robot.

What about an aid to self-right if they tip over - as if that would happen.

Maybe they can turn it into a confetti cannon - that surely must be the latest "major redesign" mentioned on John's Facebook. :)

Re: pic: Team 148 - Robowranglers 2010 - Armadillo
 

The pole serves two main purposes, you've got the first one right. The driver can "slap" our pole onto the tower and then drive forward until the claw latch is engaged. We experimented with all sorts of "docking aids" but this simple pole worked pretty well.

The second purpose is to extend the "claw" for the purposes of self-righting the robot.

-John

Re: pic: Team 148 - Robowranglers 2010 - Armadillo
 

We refer to the 5-omni setup as something called a "Slide Drive". When you combine a slide drive with 4 drop down traction wheels you get what we're calling "Nonadrive" (not Nano Drive as Mike Copioli seems to think...)

Why do we use a slide drive?

Here is the quantitative part:
1. This drive allows for the front and rear wheels to be "linked" without needing a ball differential or anything like that. If one wheel comes off the ground, you still have the full power available on the other wheel.

2. We have 4 motors worth of power pointing forward/backward at all times. With a Mecanum drive, you only get part of this. (The mecanum drive has better side-side power than our 1-CIM, but we don't care.

3. The "slide drive" part of the Nonadrive is 100% intuitive to control, with ZERO programming. This is not meant to discount the efforts of our incredible programmers (148 and 217 have some GREAT ones), but the slide drive can be fully utilized with default code, and its control would be identical to Halo, Call of Duty or any other FPS videogame.

Here is the "not so quantitative" part:

This will be a controversial statement...
In all of my competition robotics experience I have never encountered any drivetrain (swerve, mecanum, or omni) that drives as well as our slide drives. Maybe it has something to do with a lack of programming. Maybe it has something to do with a driver's mental block. I don't know. What I do know is that you put a slide drive in the hands of a good FRC driver, and they'll be almost immediately doing maneuvers that make your head spin.

Before you knee-jerk and reply, remember who you're talking to. We understand design tradeoffs. We understand your value propositions may be different than ours.

Honestly, I expected more people to ask us "Why the heck did you do THAT instead of just doing a swerve or mecanum drive?" My answer is... "If you built one and drove it, you'd understand."


Nope. The slide wheel is positioned near enough to the CG that she moves sideways almost straight as an arrow. The same can be said for forward and reverse, even without the traction wheels down. No complicated control needed. For testing (before we had any of the other electronics wired up) I took a VEX PIC Microcontroller from inventory, hooked the Victors up and we drove it with default code. Really.

-John

Re: pic: Team 148 - Robowranglers 2010 - Armadillo
 

Someone asked earlier,
When the traction wheels are down, ALL the omni wheels are lifted off the ground. We further lift the center one to allow for traversing the bumps. On the fall prototype, this wheel didn't need to be lifted so it was just spring-loaded downwards.

Curious about how a drivetrain performs with (4X) 2"-wide high traction wheels located on the outer corners in a "narrow body" configuration?
Check out this whitepaper: http://www.chiefdelphi.com/media/papers/1443
You should be able to tell me how it handles...
This was not an accident, but a desired feature of the Nonadrive.

Also note... we have the front and rear pneumatic cylinders on different solenoids. This allows us to independently drop the front/rear traction wheels. We call this "2+2 Mode." When you're in 2+2 mode, the drivetrain turns about a point directly in between the two lowered traction wheels. This allows the driver some cool handling options.

Our primary drive mode is on 5-omnis.
We only use 2+2 Mode and Traction Mode for specialized operations and circumstances.

-John

Re: pic: Team 148 - Robowranglers 2010 - Armadillo
 

Hmm. I wouldn't have thought of it as a desired effect ... interesting.

Re: pic: Team 148 - Robowranglers 2010 - Armadillo
 

Do you have any programming that gives you a psuedo-omnidirectional drive when in the 5-wheel setup, or is setup as tank with strafing?

Re: pic: Team 148 - Robowranglers 2010 - Armadillo
 

It cannot translate straight while rotating automatically (if that is what you're asking about...)

Seriously... to get an understanding of how it works, think of playing Halo. Any move you can make (X-Y direction only ;)) the robot can do with default code. It doesn't take a good driver to arc about a fixed point outside the robot.

Re: pic: Team 148 - Robowranglers 2010 - Armadillo
 

he means circle-strafing. keep in mind this is also using the two analog sticks on the x-box controller, this maneuver would be harder using KOP joysticks. i cant wait to see their operator interface this year, they are always so elegant, and portable!

also, a really talented driver could "translate straight while rotating automatically", if you can do it in halo, you can do it with nonadrive. theoretically. this would involve making the drive vector point in the same direction relative to the field, i.e. spinning the movement stick while keeping the rotation constant. easier said than done, but i have seen it in halo.

Re: pic: Team 148 - Robowranglers 2010 - Armadillo
 

I think you may have misunderstood what I was asking, though the more I read your response the more it seems like you might have gotten it.

Many, including you, have seen my personal feelings about [pure] mecanum drives (you even commented on my facebook rant). I wasn't suggesting comparing the nonadrive to a simple mecanum.

But rather I was comparing the "slide drive" portion of it to a mecanum drive. You could replace the four omni-wheels with mecanums and still be able to accomplish any strafing with equal results.
You are also correct about a mecanum drive losing power when wheels lose contact with the ground (barring, as you mentioned, differentials of some sort). This isn't a major issue with chain/gear-linked "sides" of drive trains.
Granted, I was operating under the (apparently incorrect) assumption that you would be operating in the traction wheels drive configuration for most forward/reverse driving (though even a "2+2" also applies to my assumption). The "slide drive" does, in fact, move in forward/reverse more efficiently than a mecanum drive.
Operating under that assumption, I was basically considering the two drives in terms of strafing and rotational ability, in both of which the mecanum drive is advantageous compared to the slide drive.

Knowing the characteristics of the traction wheel set-up, it really comes up to how you want to drive the machine in order to justify any engineering trade-offs. Given the way you stated you wanted to drive it, I absolutely understand the reasoning behind your design choices.

Also note, I never was attempting to call into question your design choices, but rather just seeking more information about why you made the ones you did. And there were indeed some factors I didn't take into consideration, and learned more about your design philosophy and your strategy for playing the game.

I was more wondering about diagonal motion. With different total torques in either cardinal direction, an input of a "45 degree motion" isn't going to immediately produce a 45 degree motion from the robot because the acceleration in each cardinal direction will be different. Granted, this could be accomplished by using different gearing on the wheels, but then the total speeds would have to be reduced (on the faster geared wheels only, obviously) in order to produce a 45 degree motion.
This really isn't a big concern at all, I was just curious if you felt it was an issue. It's easily adaptable by a skilled driver (though we all know that kid down there can't drive his way out of a paper bag, so maybe he might need programming help ;) ).

As a side note, how is she going to be controlled? Given the amount of options available, I'd assume you're using some sort of game controller in order to have enough buttons readily available to the driver.

Re: pic: Team 148 - Robowranglers 2010 - Armadillo
 

Ah. I was going to ask about that. Makes a whole lot of sense! This isn't the only robot you'll see in 2+2 mode... ;)

But in 2+2 mode, doesn't the CG placement affect the pivot point? I thought you pivot about a point that's a sort of an "average" of 1.) the point between the traction wheels and 2.) the CG. Is that not right?

Re: pic: Team 148 - Robowranglers 2010 - Armadillo
 

Is the top roller the only one that is powered, or does the bottom one spin also?

Re: pic: Team 148 - Robowranglers 2010 - Armadillo
 

I find myself watching this video over and over just because I don't know the name of the song. :p Anyone know the name?

Re: pic: Team 148 - Robowranglers 2010 - Armadillo
 

I endured the torture of straining to discern English utterances in between all the screaming and ultimately happened upon...

Refused - New Noise

http://www.youtube.com/watch?v=K8MkVIe9xGc

I vote for Dean Simmons to cover this at IRI. Bring back the mosh pit from '04!

Re: pic: Team 148 - Robowranglers 2010 - Armadillo
 

I just love the "death spin". Did I hear JVN or Paul allude to the magnet being able to hold a ball while deathspinning? I'm DYING to see that.

Re: pic: Team 148 - Robowranglers 2010 - Armadillo
 

In 2008, your Tumbleweed robot had me befuddled on how it could possibly win ANY matches at all, and produced a laughing response from our team captain. And it won at the Championship.

This robot has me asking myself how it the world could it NOT win.

Your robot is amazing. I love your drive train. Good luck, not that you'll need it.

Re: pic: Team 148 - Robowranglers 2010 - Armadillo
 

It won because of the amazing ability of 148 to work with their alliance partners in ways that were a combination of dance, art, and tough competitive brilliance, even when Tumbleweed struggled at times. I thought it was visionary. If you ever get a chance to talk to members of 148 about Tumbleweed, do it.

I hope to hear a lot about Armadillo in that same (but different) amazing way. She's got the moves.

Jane

Re: pic: Team 148 - Robowranglers 2010 - Armadillo
 

When I say I was befuddled, it was before I actually saw them in any matches. Once I saw a few matches, I thought they were interesting, but I still didn't think they'd win.

This year, MARS is emphasizing the value of teamwork, like they did with Tumbleweed, with a ramp robot.

We indeed learned the importance of alliance support from them in 2008.

Re: pic: Team 148 - Robowranglers 2010 - Armadillo
 

Holy #$@%!!! that is insane...nice work like the kicker design...I wish our team thought of that...and i like lifter, that thing is beaslty, what regionals are yall going to by chance?

Re: pic: Team 148 - Robowranglers 2010 - Armadillo
 

Since Armadillo's twin Mia is competing this weekend and word will probably be out soon anyways, I thought I'd take a minute to discuss a somewhat "controversial" change we made to the robot...

Here is the rough timeline:
Our video was shot on the Saturday before ship, the video itself was edited during the day Sunday and released that Sunday evening... On Monday evening the Robowranglers held an open-house for the Greenville community, then put the robot in the crate late that night (early the next morning).

After the video shoot on Saturday night we (in typical "continuous improvement" fashion) began to discuss what we needed to improve.

We were concerned about the durability of the drivetrain, but didn't have any weight to spare to reinforce it. We were also disappointed at the way the robot traversed the bumps and felt lowering the CG would greatly improve the robots performance.

Early on in our game analysis (day of kickoff) we were trying to do cost-benefit analysis to determine how much those 2-points for hanging would really be worth. At the time we couldn't really tell, because we had no idea how hard it would be to score and had no "easy" way to simulate it. Playing with the actual robot gave us more of an idea of how many balls a match a robot could score.

At the start of our meeting Sunday, we made the decision to remove the hanging mechanism. We would use that weight to reinforce the drivetrain, and lower the CG. By the time the video was posted on Sunday night, the new "baller" Armadillo was up and running. She goes over the bumps smooth as silk forward and backwards, and the drivetrain has been significantly reinforced.

I know some people will question our decision to give up the hanging. I see it as a "no-brainer". When the decision was made, it was like a weight was lifted from my shoulders.

The Thunderchickens went through a similar analysis and made the same decision. Neither robot will be hanging for 2 points this year.

So thank you for all the compliments on our hanging, but you won't ever see Armadillo or Mia do that in competition. Instead you'll see a new-and-improved version of the drivetrain, on a lean, mean, soccer-ball scoring machine.

-John

Re: pic: Team 148 - Robowranglers 2010 - Armadillo
 

Our hanger is also the first thing to go when we add our new kicker for Boston.

I was wondering though, could you please still bring the arm with you to Atlanta? I'd love to get a nice look at it.

Re: pic: Team 148 - Robowranglers 2010 - Armadillo
 

We put it in the crate, it'll be there.

Re: pic: Team 148 - Robowranglers 2010 - Armadillo
 

Sweet, thanks :D

Re: pic: Team 148 - Robowranglers 2010 - Armadillo
 

Thats too bad, I really liked your arm.

And thats leads me to a question I have, how much does your drivetrain weight?

Robot looks great by the way, maybe we'll be in same division :)