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You aren't crazy, everyone seems to be talking about swerves this offseason. Data taken from CD search results then broken into 1/2 year periods and graphed.
Discussion
view entire thread
31-12-2014 12:04
mrnoble
Re: pic: 2015, Year of swerves?
I stand in awe of the pioneers who created the early swerve, crab, etc. drives. I drool over pwnage's drive from last year. But my team doesn't need swerve to do what they do. Who said swerve "is never necessary"? Anyway, kudos to the amazing teams that have moved the game forward.
31-12-2014 12:12
Michael Hill
Re: pic: 2015, Year of swerves?
This will be the return of 1/4 of the robots not moving at their first competition if it is.
31-12-2014 12:14
Re: pic: 2015, Year of swerves?
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Originally Posted by mrnoble
Who said swerve "is never necessary"?
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31-12-2014 12:27
SoMe_DuDe904
Re: pic: 2015, Year of swerves?
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Originally Posted by Andrew Lawrence
I'd rather have moving alliance partners...
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31-12-2014 12:51
Chadfrom308
Re: pic: 2015, Year of swerves?
A lot of people are bagging on swerve, but in all honesty, I think people who do swerve will be able to move. I have seen a lot of offseason projects, so if they programmed it and tested it and created offseason drivetrains, I think they will do just as well as anyone else.
To extend my opinion, I think that swerve is most of the time not necessary. If a team doesn't have resources and does swerve, then they are going to sacrifice game / end effectors.
31-12-2014 13:30
techtiger1
Re: pic: 2015, Year of swerves?
Why swerve? At least 2 of the 4 championship winners will have 6 or 8wd next year.
31-12-2014 13:34
cadandcookies
Re: pic: 2015, Year of swerves?
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Originally Posted by Chadfrom308
A lot of people are bagging on swerve, but in all honesty, I think people who do swerve will be able to move. I have seen a lot of offseason projects, so if they programmed it and tested it and created offseason drivetrains, I think they will do just as well as anyone else.
To extend my opinion, I think that swerve is most of the time not necessary. If a team doesn't have resources and does swerve, then they are going to sacrifice game / end effectors. |
That said, I think the resources available for teams to do swerve are ininitely better than they were then.
I'll be interested to see how many swerves pop up for the 2015 season.
31-12-2014 13:40
IronicDeadBird
Re: pic: 2015, Year of swerves?
Unicycles are hip I think those have a fair shot too
31-12-2014 14:04
Kevin Ainsworth
Re: pic: 2015, Year of swerves?
Why did someone design a car when they had horses?
Why do people build 1000 horsepower cars for the street?
Why did someone design an electric powered car when there are gasoline engines?
Don't stifle creativity.
This competition to me is a way to teach the students about engineering.
Through success and failure, the journey is what's important.
If you use the same drivetrain design year after year, what are you teaching about designing a drivetrain?
Most will argue they put the time into the mechanisms for that years game and that is a valid argument.
Some are in it to win at any cost and some are in for the fun of it.
I agree swerves are not necessary to win, thus far.
Pnwage has discussed this at length and we are not a "Swerve Team".
It helped us seat first and win our first regional last year but it had it's negatives at Champs and at IRI.
A four CIM swerve does not accelerate like a six CIM tank.
The extra mobility doesn't help if the other team can get there quicker.
A single speed swerve does not get out of a pushing match if it's geared for speed, and it doesn't move quickly if it's geared for pushing matches.
Our swerve is now fully Field Centric, with only a few degrees of drift over an entire match. My 9 year old jumped on the sticks and drove it to 90% its capacity the first time he drove it. Now anyone can be your driver, not just the best "driver". Can you say that about a tank drive?
Now if we could just get the same acceleration as the 6 CIM tanks...
Ah, 8 mini-cims...
31-12-2014 14:48
Bryce2471
Re: pic: 2015, Year of swerves?
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Originally Posted by Kevin Ainsworth
Why did someone design a car when they had horses?
Why do people build 1000 horsepower cars for the street? Why did someone design an electric powered car when there are gasoline engines? Don't stifle creativity. This competition to me is a way to teach the students about engineering. Through success and failure, the journey is what's important. If you use the same drivetrain design year after year, what are you teaching about designing a drivetrain? Most will argue they put the time into the mechanisms for that years game and that is a valid argument. Some are in it to win at any cost and some are in for the fun of it. I agree swerves are not necessary to win, thus far. Pnwage has discussed this at length and we are not a "Swerve Team". It helped us seat first and win our first regional last year but it had it's negatives at Champs and at IRI. A four CIM swerve does not accelerate like a six CIM tank. The extra mobility doesn't help if the other team can get there quicker. A single speed swerve does not get out of a pushing match if it's geared for speed, and it doesn't move quickly if it's geared for pushing matches. Our swerve is now fully Field Centric, with only a few degrees of drift over an entire match. My 9 year old jumped on the sticks and drove it to 90% its capacity the first time he drove it. Now anyone can be your driver, not just the best "driver". Can you say that about a tank drive? Now if we could just get the same acceleration as the 6 CIM tanks... Ah, 8 mini-cims... |
Although I'm not sure that 8 mini-CIMs is the best solution to your acceleration deficit.
Building swerves for the first time last year was a good decision for my team. Even though it barely helped us in competition that year, it stretched our abilities and our knowledge. (It also helped my best friend get into MIT, and helped me win the Dean's List Award)
31-12-2014 16:25
Pault
Re: pic: 2015, Year of swerves?
Swerve is good because it is one of the few things that you can completely build and test during the offseason, and then it almost always will make you more competitive come the next season (assuming your team has the resources to complete it and then easily replicate it during the build season, which many teans don't). No, it is never necessary, but it often gives a huge advantage. Look at 16 in 2012; they were one of the few IRI caliber "feeder bots" because of their swerve. Or 2000, when the second iteration of the original swerve by 47 allowed them to remove balls from the opponent's trough, slide sideways to their own, and score the balls. Or any game where you need to pick up a game piece, and swerve allows you to better manuever the field and pick them up. I would not consider it waste of time, so long as you have the resources to do it and make sure to get plenty of driver practice.
31-12-2014 16:29
Thad House
Re: pic: 2015, Year of swerves?
Also, 2009 was a year where swerve was very advantageous. We better not, but if we have a game like that again, with all the COTS options I could see alot of teams doing it.
31-12-2014 16:58
asid61
Re: pic: 2015, Year of swerves?
I thought that graph was pretty accurate.
Anyway, many swerves may not be built for 2015. 2016 will have more swerve drives IMO.
Well, "swerve is never necessary" is like "moving is never necessary". You can sit still for a whole match with blinking lights and compete with that. Great. However, it's probably advantageous to move a little bit at least.
31-12-2014 17:07
mrnoble
Re: pic: 2015, Year of swerves?
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Originally Posted by asid61
Well, "swerve is never necessary" is like "moving is never necessary". You can sit still for a whole match with blinking lights and compete with that. Great. However, it's probably advantageous to move a little bit at least. |
31-12-2014 17:15
hzheng_449
Re: pic: 2015, Year of swerves?
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Originally Posted by Thad House
with all the COTS options I could see alot of teams doing it.
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In order to get the full benefits of swerve (or really any omni direction drive for that matter), you really need to be able to implement a good control scheme that is exponentially more difficult to do than a control scheme for WCD.
Also as a side note: I think that some of the initially negative posts about swerve on this thread we're saying "Swerve is useless", but were saying "A lot of teams are going to underestimate the challenge of implementing swerve during build season and will subsequently not have functional/effective drive bases come competition time". (Disclaimer: That's just my interpretation and I don't want to put words into anyone's mouth)
31-12-2014 18:13
Abhishek R
Re: pic: 2015, Year of swerves?
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Originally Posted by asid61
I thought that graph was pretty accurate.
Anyway, many swerves may not be built for 2015. 2016 will have more swerve drives IMO. Well, "swerve is never necessary" is like "moving is never necessary". You can sit still for a whole match with blinking lights and compete with that. Great. However, it's probably advantageous to move a little bit at least. |
31-12-2014 18:38
MichaelBick
Re: pic: 2015, Year of swerves?
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Originally Posted by Abhishek R
That argument doesn't make a whole lot of sense. I can think of several counterexamples, but I would rather you reword the post because I think you might have meant something else...I assure you as a driver myself that swerve is never necessary, whereas moving is. The best drivetrain is the one that gets you from point A to B the quickest, and if that drivetrain for you is swerve, then that works out nice. But for a lot of teams, it seems like a standard tank drive accomplishes that goal just fine.
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31-12-2014 18:55
Abhishek R
Re: pic: 2015, Year of swerves?
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Originally Posted by MichaelBick
The goals of a good drivetrain depend on the team. I think for most teams a reliable and easily maintainable drivetrain are far more important than everything else. For many teams, agility and speed are far lower on that list than you would think, and therefore swerve isn't prioritized.
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31-12-2014 19:06
efoote868
Re: pic: 2015, Year of swerves?
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Originally Posted by asid61
I thought that graph was pretty accurate.
Well, "swerve is never necessary" is like "moving is never necessary". You can sit still for a whole match with blinking lights and compete with that. Great. However, it's probably advantageous to move a little bit at least. |
31-12-2014 19:34
jman4747
Re: pic: 2015, Year of swerves?
I don't know why you all are here but I joind FRC to make cool robots and because when I saw 2010 champs back when I was too young to compete I thought that there was no way I could do all that (looking at some team electrical system. I could design a WCD in a day or two now.
I don't care about WCD. I don't want to try and shave a 1/4lb of my sixth iteration of a WCD. I want to actually look around in the Math section in LabVIEW and know what an "arc tangent" is. Enough with this 6WD 8WD is on some special peice of carpet. I hope I never win champs with the same old boring robot as 2K other teams. It better be the coolest most difficult, fun to talk about and look at and think about and know that it was hard and I learned somthing.
If you don't have money figure out how to do it with less.
If you don't have the tools figure out how make it without.
Be an engineer solve the challenge.
31-12-2014 19:56
Woolly
Re: pic: 2015, Year of swerves?
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Originally Posted by Michael Hill
This will be the return of 1/4 of the robots not moving at their first competition if it is.
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31-12-2014 20:02
magnets
Re: pic: 2015, Year of swerves?
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Originally Posted by jman4747
I hope I never win champs with the same old boring robot as 2K other teams.
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It's your responsibility that your entry to the FIRST Robotics Competition be your team's best competitive entry. If you decide that swerve is the best thing for your team, and it turns out to be unreliable, I might think you made a silly, but understandable, mistake. If you realize that swerve will lower both your rankings, and the rankings of those who must play with you, and you still decide to build it, it reflects poorly on your team.
31-12-2014 20:09
Abhishek R
Re: pic: 2015, Year of swerves?
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Originally Posted by jman4747
I don't know why you all are here but I joind FRC to make cool robots and because when I saw 2010 champs back when I was too young to compete I thought that there was no way I could do all that (looking at some team electrical system. I could design a WCD in a day or two now.
I don't care about WCD. I don't want to try and shave a 1/4lb of my sixth iteration of a WCD. I want to actually look around in the Math section in LabVIEW and know what an "arc tangent" is. Enough with this 6WD 8WD is on some special peice of carpet. I hope I never win champs with the same old boring robot as 2K other teams. It better be the coolest most difficult, fun to talk about and look at and think about and know that it was hard and I learned somthing. If you don't have money figure out how to do it with less. If you don't have the tools figure out how make it without. Be an engineer solve the challenge. |
Besides that, you can definitely be unique in other ways than the drivetrain. 254 this year was pretty much one of a kind despite using a fairly standard drivetrain (though they were the one of the first teams to popularize the system).
31-12-2014 20:20
asid61
Re: pic: 2015, Year of swerves?
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Originally Posted by Abhishek R
That argument doesn't make a whole lot of sense. I can think of several counterexamples, but I would rather you reword the post because I think you might have meant something else...I assure you as a driver myself that swerve is never necessary, whereas moving is. The best drivetrain is the one that gets you from point A to B the quickest, and if that drivetrain for you is swerve, then that works out nice. But for a lot of teams, it seems like a standard tank drive accomplishes that goal just fine.
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When somebody says, "Swerve is never necessary" it's basically just stating a universal truth. That quote just kind of irks me because of that. Yes, swerve is never necessary. Neither is driving. But, driving, and swerve drives, are advantageous. And it's that distinction that the quote totally misses.
What I mean is that swerve, when practiced with in the offseason and with a good driver, is almost always a benefit IMO. You're getting all the capabilities of a tank, it can be configured to drive like a tank, and if you want to you can switch over to swerve anytime. Now, if you just try to make a swerve when the season begins, I can see how a team might flop. But provided you actually prototype in the offseason, it's a lot less likely to fail.
Open-source the designs and code, manufacture early in the season, and you're good. A well-designed swerve drive is lightweight and compact nowadays, to the point where it can compete with a WCD. For some teams it's not easy to manufacture it at all, and for them swerve is in fact disadvantageous. But if you can get it made fast and you have working code pre-season, I don't see the inherent disadvantages of a swerve drive.
"The best drivetrain" can mean a lot of things depending on the game. But provided the programming and design work are done pre-season, swerve is not inherently disadvantageous.
31-12-2014 20:25
AdamHeard
Re: pic: 2015, Year of swerves?
Have your fielded a swerve drive during season?
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Originally Posted by asid61
Well, I look at it this way:
When somebody says, "Swerve is never necessary" it's basically just stating a universal truth. That quote just kind of irks me because of that. Yes, swerve is never necessary. Neither is driving. But, driving, and swerve drives, are advantageous. And it's that distinction that the quote totally misses. What I mean is that swerve, when practiced with in the offseason and with a good driver, is almost always a benefit IMO. You're getting all the capabilities of a tank, it can be configured to drive like a tank, and if you want to you can switch over to swerve anytime. Now, if you just try to make a swerve when the season begins, I can see how a team might flop. But provided you actually prototype in the offseason, it's a lot less likely to fail. Open-source the designs and code, manufacture early in the season, and you're good. A well-designed swerve drive is lightweight and compact nowadays, to the point where it can compete with a WCD. For some teams it's not easy to manufacture it at all, and for them swerve is in fact disadvantageous. But if you can get it made fast and you have working code pre-season, I don't see the inherent disadvantages of a swerve drive. "The best drivetrain" can mean a lot of things depending on the game. But provided the programming and design work are done pre-season, swerve is not inherently disadvantageous. |
31-12-2014 20:30
jman4747
Re: pic: 2015, Year of swerves?
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Originally Posted by magnets
It's your responsibility that your entry to the FIRST Robotics Competition be your team's best competitive entry. If you decide that swerve is the best thing for your team, and it turns out to be unreliable, I might think you made a silly, but understandable, mistake. If you realize that swerve will lower both your rankings, and the rankings of those who must play with you, and you still decide to build it, it reflects poorly on your team.
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Also "same old robot as 2k other teams" is unfair, I'm sorry. But if I can help it I won't try to have my systems fundamentally similar to most teams because that's the easiest rout. I'll make it because it's the best I can do with what I have.
31-12-2014 20:37
asid61
Re: pic: 2015, Year of swerves?
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Originally Posted by AdamHeard
Have your fielded a swerve drive during season?
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Not yet, much to my annoyance. However, if I didn't hold the belief that I outlined in my posts, then we never would.
Could you explain how a design that works in the offseason, code and mechanism, would fail in the season?
31-12-2014 20:51
artK
Re: pic: 2015, Year of swerves?
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Originally Posted by jman4747
I don't care about WCD. I don't want to try and shave a 1/4lb of my sixth iteration of a WCD.
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| I want to actually look around in the Math section in LabVIEW and know what an "arc tangent" is. |
| Enough with this 6WD 8WD is on some special piece of carpet. I hope I never win champs with the same old boring robot as 2K other teams. It better be the coolest most difficult, fun to talk about and look at and think about and know that it was hard and I learned something. |
31-12-2014 20:55
mrnoble
Re: pic: 2015, Year of swerves?
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Originally Posted by asid61
Could you explain how a design that works in the offseason, code and mechanism, would fail in the season?
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31-12-2014 21:08
KamalRC
Re: pic: 2015, Year of swerves?
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Originally Posted by mrnoble
Sure, and for many other things besides swerve. The competition environment is exponentially more demanding on any robot than off-season work.
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31-12-2014 21:12
jman4747
Re: pic: 2015, Year of swerves?
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Originally Posted by artK
Iteration isn't always about saving weight, even on a drive base. In my four years with 254, we never used the same drivetrain twice. In 2012, we attached pistons and small levers to help push us over the bump. In 2013, we developed a PTO in the gearbox to climb the pyramid. In 2014, we had to make the gearbox have a low profile so the balls could fit inside the robot.
Personally, I would want to know what quintic hermite spline interpolation is, but I always liked polynomials more than trigonometry. As a developer of a boring robot, I feel so awful about winning the championship, because our robot was so boring and uninspiring to watch. |
That's more of a general statement in response to the notion that winning is the metric of doing your best and that someone should build a subsystem because it wins and is easy for them rather than because it is the best they can do. It's not about what you make it's why. I am not putting down 254 or anyone else for doing well with a specific system. I'm also not saying you really have to be original you should however push your own envelope as much as possible.
To the weight thing... I mean make an example of a situation where a team would become comfortable with building something to the point where the only new thing done with it from year to year would be minor optimizations that don't generally teach anything new to those working on it precisely because they are so comfortable with it. What you described were tangible optimizations and upgrades made to better complete the game.
31-12-2014 21:13
Re: pic: 2015, Year of swerves?
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Originally Posted by asid61
Well, I look at it this way:
When somebody says, "Swerve is never necessary" it's basically just stating a universal truth. That quote just kind of irks me because of that. |
31-12-2014 21:17
BJC
Re: pic: 2015, Year of swerves?
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Originally Posted by jman4747
I think I have a responsibility to be the best I can and for this team to be the best it can this year and next. To me that means that I should try to push the limits of my current abilities. I realize I sound too condicending towards teams who did make it to and win Einstein, however winning is not the primary perpose of building a great machine, building a great machine is. There is a difference between doing your best in rankings/placement than doing your best as an engineer and student. Our "best" issn't what gives us the best chance of winning it's what was hardest for us regardless of necessity.
Also "same old robot as 2k other teams" is unfair, I'm sorry. But if I can help it I won't try to have my systems fundamentally similar to most teams because that's the easiest rout. I'll make it because it's the best I can do with what I have. |
1. The most successful teams in this program are also consistently pushing their own boundaries in an attempt to be the best. Just because you don't know what those improvements are doesn't mean they aren't there.
2. I cannot speak for other teams, however, at the beginning of the build season our problem statement is to win the World Championship. As such, our robots are built for the sole purpose of winning matches. We implement features and push boundaries that we think will contribute to this goal.
3. When your team participates in this competition you start with a set of rules and a set objective. There isn't actually any room for your own definition of "great" engineering or what the "best" robot is. These are quantitatively defined by on-field results independent of thoughts, feelings, and opinions. That is the nature of competition.
Cheers, Bryan
31-12-2014 21:23
asid61
Re: pic: 2015, Year of swerves?
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Originally Posted by Andrew Lawrence
Well I'm sorry, but it is a universal truth at the current time. They keyword isn't never, it's necessary. Swerve is never necessary. There is no situation in modern day FRC where the only possible solution is swerve. Until FIRST makes a game where swerve is required, the phrase, "Swerve is never necessary" will be a universal truth. If that statement were false, the only winners of Einstein would be swerve drives, and I know you're a smart kid who follows FRC and its history, so you know that's not the case. Can swerve be advantageous for some? Certainly. Is it ever necessary though? Never.
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31-12-2014 21:29
piersklein
Re: pic: 2015, Year of swerves?
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Originally Posted by jman4747
However winning is not the primary perpose of building a great machine, building a great machine is. There is a difference between doing your best in rankings/placement than doing your best as an engineer and student.
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31-12-2014 21:52
jman4747
Re: pic: 2015, Year of swerves?
If the only thing about FIRST that mattered was competition what then of GP? Why does the game change every year? What of the Chairman's award? None of those are necessary for competition. We are here primarily to learn and inspire not compete. The competition serves as a catalyst and goal not the primary focus of FIRST or FRC. That mentality of build a robot primarily to win and compete only hits part of the point. If I had the same opinion back in 2010 I wouldn't be here. I'd have said "wow that looks hard and not necessary therefore I will not do it" not "wow that looks hard, I should find a team somewhere." As a teenager I don't need to know what an FPGA is or the free speed of a CIM motor. Yet a while ago I decided to learn some interesting yet normally useless information for my day to day life. Why bother knowing how planetary gearboxes work? Yet it will be advantageous later in life as an engineer. Similarly: Swerve is advantageous from a learning perspective and competitively if done well. I don't need to know how, you don't need to know how but you will know that much more. Why did you join FRC to win a competition or to learn more about engineering, math, pizza, water games, and teamwork?
31-12-2014 22:27
sanddrag
Re: pic: 2015, Year of swerves?
We've wanted to make one for probably a decade now, and still never have. We've been doing FIRST for 14 years now, we have mentors who have been doing it nearly as long, we have full in-house CNC manufacturing capabilities, machining mentors, a very well educated programming mentor from a highly-esteemed institution, and students with 3 full years experience behind them. We have the capability to build two identical robots ( and have done so twice) and access to a full size practice field.
We have downloaded and studied the CAD models of other teams' swerve drives and have twice begun modeling one of our own.
We still have not built a swerve and it's not likely that we will for 2015.
Why not? Years ago our team decided that we would never build a swerve drive during build season unless we'd previously done it during the offseason., and that never happened.
What is our reasoning for that decision? We've determined that the marginal performance gains in the drive system do not outweigh the additional time requirements to design, fabricate, refine, and program it. That time can be spent further developing and refining other parts of the robot.
And this is what frustrates me a little bit about the current state of COTS items. Years ago, teams could gain a significant advantage by heavily investing in the design, development, and manufacturing of these complex systems. Now, you're at a large disadvantage if you choose to do something custom over buying it. Why, you've lost time you literally could have bought. But buy buying it, you've lost the learning process. We're teaching students how to pick things out of a catalog (which is a great skill to have!) rather than teaching them to make the things that are in the catalogs (or better yet not in any catalogs). But, that's another discussion for another thread.
Part of our "problem" is that we doall the manufacturing in house. We can't spend 4 weeks on CAD, send it out to be laser cut and bent on a CNC press brake, and get a robot back in 3 days. We don't have that kind of sponsor like some teams do. If we don't have the mill running on day 2, we don't finish. And that's with a WCD.
31-12-2014 23:03
wilderbuchanan
Re: pic: 2015, Year of swerves?
My Team got the Wild Swerve kit from Team 221 before i got involved in the team and it didn't work out so well. It took us the summer and someof the fall to get it to be mechanically sound. We made a fatal mistake and didn't get the hubs thats allow for the wires to come up the middle. Our programmers worked the whole summer and fall on code. We gave them the robot the day before our fall comp it didn't work out. They then continued to work on the Swerve during the rest of the fall getting no results.
Even though i'm a freshman, i have been to competitions since 2012. I always saw the Swerve as the Holy Grail (1717). However after working with it i can tell you that you need to make sure you have the resources. You need to fully think it through even when buying the pre fabricated versions. Otherwise you will be getting a lot of over night shipping. It was also over the heads of our 4 programers who were used to meccanum drive. For a team with middle of the road fiancees I think that it was a bad decision even though it seemed super cool. Make sure to go through both the upside and downside for your team. The pre fabricated versions also way a lot as well (80x20). We will continue to work on the swerve drive over the next few years but it has become more of a long term goal for us.
31-12-2014 23:21
artK
Re: pic: 2015, Year of swerves?
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Originally Posted by jman4747
That's more of a general statement in response to the notion that winning is the metric of doing your best and that someone should build a subsystem because it wins and is easy for them rather than because it is the best they can do. It's not about what you make it's why.
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| I am not putting down 254 or anyone else for doing well with a specific system. I'm also not saying you really have to be original you should however push your own envelope as much as possible. |
| To the weight thing... I mean make an example of a situation where a team would become comfortable with building something to the point where the only new thing done with it from year to year would be minor optimizations that don't generally teach anything new to those working on it precisely because they are so comfortable with it. |
31-12-2014 23:52
VioletElizabeth
Re: pic: 2015, Year of swerves?
I was looking at the graph, and realized that the spikes were not the offseason like I thought they were but instead during the season (or rather, the first 6 moths of the year, which is 2/3 during the season) (if I'm reading it correctly), except for this year. Seems like the advice to do it in the offseason first has sunk in.
01-01-2015 01:48
MichaelBick
Re: pic: 2015, Year of swerves?
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Originally Posted by asid61
"The best drivetrain" can mean a lot of things depending on the game. But provided the programming and design work are done pre-season, swerve is not inherently disadvantageous.
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01-01-2015 02:16
asid61
Re: pic: 2015, Year of swerves?
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Originally Posted by MichaelBick
It is completely dependent on what type of swerve you are running, but in all swerves you use up more motors and in independent swerve you actually tend to push worse(wheels come off the ground)
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Plus, why push when you can a) lock wheels in an x and not move at all or b) Leroy Jenkins out of there.
01-01-2015 03:21
Dunngeon
Re: pic: 2015, Year of swerves?
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Originally Posted by asid61
Put when you push, you can choose to push in exactly the direction you want, which may lend a greater advantage.
Plus, why push when you can a) lock wheels in an x and not move at all or b) Leroy Jenkins out of there. |
01-01-2015 04:20
nathannfm
Re: pic: 2015, Year of swerves?
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Originally Posted by jman4747
Why did you join FRC to win a competition or to learn more about engineering, math, pizza, water games, and teamwork?
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Wow, I didn't expect this to generate this much philosophical discussion of the objectives of FRC and the COTS vs. Custom argument, but i'm not complaining.
Can't wait to see what 2015 brings.
01-01-2015 05:02
asid61
Re: pic: 2015, Year of swerves?
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Originally Posted by Dunngeon
Do you have any first hand experience with this x arrangement you keep referring to? As a drive coach, our drivers have never had issues pushing a swerve with x locked wheels, except in the case where we are 90lbs and they are 120lbs.
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However, there is no way to avoid overcoming the friction of the wheels if the swerve is locked in such a formation. Unless you push with enough force to rotate the modules out of the formation (extremely unlikely), you are basically dealing with the whole weight of the robot times COF. If you can overcome that, then bully for you.
If you push only the corner of the swerve, then it might be easier to push versus a head-on assault.
As an aside, putting the wheels in such a formation makes it very quick to rotate the modules into their next position, making it an ideal rest position as well.
01-01-2015 05:39
pwnageNick
Re: pic: 2015, Year of swerves?
I'd like to see a graph like this made for other topics. It seems to me in general post quantity has gone up in general, and more teams are posting things they work on in the off-season then ever before. While I think people posting/working on swerve has probably increased, I think if you removed the growth of the program, the growth of presence on the forum, and the growth of openness about what teams are working on, I think this graph would probably be a lot less dramatic looking.
01-01-2015 08:32
Harman341
Re: pic: 2015, Year of swerves?
That's a beautiful graph to me. I see no point in discouraging the trend, it means teams are going beyond what they did the previous years. While next year I'll bet a lot of those teams will stand still their first match or 10. 2,3 years from now many will be experienced "swerve teams". Just saying, variety makes first more exciting and educational. 50 "swerve teams" can teach all of us more about drive trains than 10.
01-01-2015 09:10
T3_1565
Re: pic: 2015, Year of swerves?
I enjoyed reading through this thread. It shows what a lot of people think about during competition and throughout the season. A lot more then actually talking about swerve lol.
Where I think most of the discussion is coming from is a difference in what teams are trying to accomplish during the season. Everyone is trying there best to accomplish what they feel is the best goal. That's the wonder of FIRST. There are many goals to shoot for.
Take for example, My Senior year on 1565. I was team captain on a team that had never produced a good quality robot (Competitive or Engineering wise). Our team was small and had little machining capabilities. I decided to spend all summer prototyping a drive train that FIRST has never seen before. The game happened to work very well for this type of system so we built it that year to compete.
Here is the drivetrain: http://www.chiefdelphi.com/forums/sh...806#post706806
The main objective of this drive train was not, however, to win an event. It was built entirely to "put our team in the spotlight" so to speak. To generate buzz and interest in the community of FIRST as well as in our own community.
The robot did exactly what I wanted it to. We won some awards for it as a bonus and got a lot of attention at the events we attended as well as here on Delphi. But the biggest thing that happened was tripling our team from having about 10 people to have around 30.
So, Long story short, Some teams build robots to win a regional, some build to win a championship, and some build to generate interest in science, as well as many other reasons.
Swerve can be built to fit any of those goals, or built to fit none of them. Its really the choice of the team that wants to build it.
01-01-2015 12:31
matthewdenny|
Originally Posted by magnets
It's your responsibility that your entry to the FIRST Robotics Competition be your team's best competitive entry. If you decide that swerve is the best thing for your team, and it turns out to be unreliable, I might think you made a silly, but understandable, mistake. If you realize that swerve will lower both your rankings, and the rankings of those who must play with you, and you still decide to build it, it reflects poorly on your team. |
Sorry, I disagree. As a teacher my responsibility to my students is to teach them new things. Now I'm sure that someone could make different iterations of the same type drive each year and learn something. I however try to have my team do at lease 1 thing every year that is completely new. That may or may not be a swerve.
As a mentor my responsibility is to inspire the students. How many times have we heard that it's not about the robot? If my students look at the game and say "a swerve would be really cool this year" we are going to give it a shot.
We may fail. We have before. In that case we will try a contingency plan. It may fail too. In the situation that we become a hindrance in someone's team for the 2 min match, honestly we'd be sorry, but we aren't going to try to limit our ambition during a 6 week build season because of it. I think doing that would reflect more poorly on us.
01-01-2015 12:36
Ether
Re: pic: 2015, Year of swerves?
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Originally Posted by Kevin Ainsworth
Can you say that about a tank drive?
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01-01-2015 12:41
dradel
Something does get lost in the competition aspect of frc! It is a fact that can't be argued. I take that back... It can be argued for the sake of arguing it.
How many students join a robotics program with their sole intention is to win a competition?? I'd be willing to bet that the number is near zero.
01-01-2015 12:44
Travis Schuh
Re: pic: 2015, Year of swerves?
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Originally Posted by asid61
If the COF of the wheels is too low, then you'll be able to push them regardless. If you're running blue nitrile and they're using (insert something with a COF of 1.0 or lower here) and they weigh the same as you, then of course they will move around. There's no magic in an x-formation.
However, there is no way to avoid overcoming the friction of the wheels if the swerve is locked in such a formation. Unless you push with enough force to rotate the modules out of the formation (extremely unlikely), you are basically dealing with the whole weight of the robot times COF. If you can overcome that, then bully for you. If you push only the corner of the swerve, then it might be easier to push versus a head-on assault. As an aside, putting the wheels in such a formation makes it very quick to rotate the modules into their next position, making it an ideal rest position as well. |
Another thing, you talk about swerve having great pushing ability because they can direct their wheels in line with where they are pushing. I don't think it is as simple as this. Most times we are trying to push someone, we are trying to push them in the direction our robot is pointed, so our wheels are largely aligned anyways. However, we will likely have more torque behind our robot because all of our drive wheels on a side are ganged together. When a robot pushes, the weight distribution on the wheels shifts (likely back, depending on how the bumer contact goes). Also, robots typically are not balanced front-back. If you do not have a 50-50 distribution on your wheel, you will not be having as much power to the ground as a 6WD.
01-01-2015 12:47
MichaelBick
Re: pic: 2015, Year of swerves?
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Originally Posted by asid61
Put when you push, you can choose to push in exactly the direction you want, which may lend a greater advantage.
Plus, why push when you can a) lock wheels in an x and not move at all or b) Leroy Jenkins out of there. |
Assuming F is the force one motor exerts and two of the swerve robot's wheels are off the ground
4Fcos(theta) = 2F
cos(theta) = 1/2
Theta = 60*
So the "break even"point is 60*. The model is inaccurate because the 4 motor robot is actually traction limited, but the point stands. Independent swerve isn't very good at pushing matches, and its best bet is to avoid pushing altogether.
01-01-2015 13:04
Dunngeon
Re: pic: 2015, Year of swerves?
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Originally Posted by asid61
If the COF of the wheels is too low, then you'll be able to push them regardless. If you're running blue nitrile and they're using (insert something with a COF of 1.0 or lower here) and they weigh the same as you, then of course they will move around. There's no magic in an x-formation.
However, there is no way to avoid overcoming the friction of the wheels if the swerve is locked in such a formation. Unless you push with enough force to rotate the modules out of the formation (extremely unlikely), you are basically dealing with the whole weight of the robot times COF. If you can overcome that, then bully for you. If you push only the corner of the swerve, then it might be easier to push versus a head-on assault. As an aside, putting the wheels in such a formation makes it very quick to rotate the modules into their next position, making it an ideal rest position as well. |
Edit: Travis beat me to it
Also, if a team is using PID control on the modules it's nearly impossible to rotate the caster with outside forces.
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Originally Posted by dradel
Something does get lost in the competition aspect of frc! It is a fact that can't be argued. I take that back... It can be argued for the sake of arguing it.
How many students join a robotics program with their sole intention is to win a competition?? I'd be willing to bet that the number is near zero. |
01-01-2015 13:15
Abhishek R
Re: pic: 2015, Year of swerves?
An aside from the swerve vs. tank and "build to win" vs "build because it's cool" debate (all of which have arguments for):
Regardless of the drivetrain, something I have found common among the best of the best teams is that they have a drivetrain that they have iterated so much that it is pretty much a science for them. Examples include 16 and 1717's swerves or 254's WCD. I don't know what timeframe it takes the former two teams, but from 254's build blog, aside from minor changes, the luxury of having a drivetrain they know works seems to allow them to be done with it maybe 2 weeks into the build season. This allows them to focus on the other parts of the robot for the majority of the season and really produce a highly sophisticated machine. I don't think my team finished our prototype robot's drivetrain until week 4 of the build season last year (although some of that has to do with no CAD to be able to pull from for a new design - especially as it was our first year with true WCD, and the fact that we do all machining in house which as sanddrag pointed out really puts some limitations on your time and resource usage).
On another note regarding the competition debates: I am firmly in the build to win camp. From Kickoff to the end of the the last competition, I am thinking about how we can build a robot that will maximize our score in any given match, and all my strategies and design revolve around one goal - winning the match. If that results in a "simple" robot (which it never does, I wish it would for the sake of consistency and ease of maintenance) then that's completely fine with me. However, I understand that everyone has different goals, and I recognize the different viewpoints of different people.
Something I don't agree with at all is the notion that a few people seem to have that if you're not building a swerve drive you're not really experimenting or pushing yourself to the extremes of drivetrain innovation. There's a few things wrong with this, the first being that some people regard swerve a bit too highly in this thread - having a swerve drive, even a really good swerve system with great programming and great drivers, will not necessarily give you a very large advantage. I saw some of the best swerve drives from this year still get bogged down by defenders. A lot of people make an assumption that if you have good drivers, you will be able to navigate through defense - however, the people across the field are not idiots, those teams probably have good drivers as well.
We build a prototype last year that a few teams have begun iterating called the Grasshopper drive, which combines the advantages of butterfly with WCD and uses only COTS items or easy to manually mill parts. It was a successful experiment for us and we will likely use the system again, game permitting. We learned quite a few things, and it wasn't swerve. It doesn't even come CLOSE to the complexity of swerve. We were able to compete with and against some of the highest level swerve drives this year. I have yet to see a team that makes me think, "if we don't have swerve, we're gonna get rolled over in competition." This is all just my opinion however, and I do agree that swerve is a great technical challenge. But to say it is the best drivetrain hands down would be a little misguided.
01-01-2015 13:52
Ekcrbe
Re: pic: 2015, Year of swerves?
If FRC is supposed to be a real-world engineering "simulation" of sorts for students, as it sounds like some people are arguing (and fairly, because it is), then I think the build-to-win vs. build-to-learn debate comes down to one big thing.
In the real world, your efforts to be the "best" engineer should be those which produce the most effective product and best experience for your customer.
Success in accomplishing a customer's goals for a product is analogous to success in accomplishing the GDC's goals for the game. Success in playing the game is defined by on-field performance, namely winning.
Hence, by building with the intent to win the game, you have created the robot which most closely resembles the solution you should pursue in a real-world engineering project, and thus begun to learn how to be the best engineer you can.
01-01-2015 14:02
IronicDeadBird
Re: pic: 2015, Year of swerves?
I say we just go ahead and make it the year of the half track.
You know rack and pinion front two wheels the back uses tank treads.
01-01-2015 14:10
jman4747
Re: pic: 2015, Year of swerves?
I'll say that swerves are an example of doing something unnecessary yet competitively beneficial to gain experience and if you do happen to do it right an edge in competition. I never said I don't want to win I said I wanted to do something I haven't done before whenever I can and so long as it could possibly add to my competitiveness.
For instance in 2012 you didn't need to cross the middle barrier but we designed a drive train that could do it just in case. We barely used it but it came in handy when we needed it. And should a similar need arise I have a good way to do it.
The other angle is a lot of teams can't afford to make off season projects or on season prototypes. We get 1 full robot a year, 1 shot, and I'm going to at least try to do something interesting with it, doesn't need to be a drive train. It can be using encoders for the first time or using pneumatics for the first time doesn't matter. Try to do something that you aren't sure about but can help you now or later both competitively and educationally.
A rookie can learn a lot from a kit bot, a team that's made three kit bots can learn a lot from making a custom WCD drive, a team that has always made a custom WCD can learn alit from buying some 221 modules and a team that's made a swerve 3yrs in a row can learn a lot from making a octocanum.
And no I'm not referencing anyone specifically or saying drive trains are the main point of all this. Say it with me... Examples.
Another consideration is how likely would any given team be to win a regional doing only what they are comfortable with? That is to say a team that has won worlds one or more times probably is comfortable with many advanced things, so for them their comfort zone is miles ahead of the curve meanwhile a newer team my only be %90 sure with the basics. If they at least try to go for more they get one of two outcomes. #1 it didn't work but they were able to get much more knowledge to improve later or #2 it did and they are performing far better than was even just barley technically possible before.
01-01-2015 15:59
dradel
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Originally Posted by Dunngeon
Aren't you doing the exact same thing when t-boning a robot? I honestly think you're putting too much stock in the x formation, it's not as great as you make it out to be. It's potentially a slight bonus, not a primary one.
Edit: Travis beat me to it Also, if a team is using PID control on the modules it's nearly impossible to rotate the caster with outside forces. I don't like losing... I joined our team because I wanted to win anything, awards or robots. Robots that look cool but lose ( as in don't play the game well) aren't inspiring to me. |
There is a big difference between not liking to lose, and know how to lose and learning from it. Those that get all pissy when they lose are going to find the "real world" hard to handle!
02-01-2015 16:44
evanperryg
Re: pic: 2015, Year of swerves?
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Originally Posted by asid61
Well, "swerve is never necessary" is like "moving is never necessary". You can sit still for a whole match with blinking lights and compete with that. Great. However, it's probably advantageous to move a little bit at least.
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Many of the swerves that came out of 2014 are some of the best ever made, and therefore swerve gained a lot of popularity (and rightfully so, looking at you 2451). Why did we see a lot of good swerve? Because 2014 was a great game for it, and some teams have been developing a swerve for years, waiting for the opportunity to use it. Did a swerve drive win champs? No. Why? Because other robots defeated the swerve bots.
The fact is, there is no "best drivetrain." These broad generalizations like "ALWAYS USE TANK" and "SWERVE IS BETTER THAN TANK" are invalid because they attribute the success of a robot to one small aspect of the robot. Sure, the drivetrain is important, but its significance is nothing compared to everything else that goes into making a successful robot. The success of a robot is determined by every component, every design, every man-hour, every line of code, and every strategic discussion contributed to it; all of these factors are what make a robot successful, not just the drivetrain.
To respond more directly to OP, there's a lot of of post-2014 swerve hype, but it all comes down to what happens this weekend.
02-01-2015 17:14
Bryce2471
Re: pic: 2015, Year of swerves?
Disclaimer: This post reflects only my opinion.
I really like some of the discussion going on in this thread. Before reading it, I wasn't 100% locked down on what my goals were for this FRC season.
I love to win. I'm very competitive, and I've come extremely close to national titles in several other competitions before (Most notably Chess and FLL), so one of my main goals this season (along with most other people) is to win. However, my view on this competition has been molded over the years, and after winning the Dean's List Award last year; I really want to inspire people on my team, and on others.
This was a battle going on in my mind for the past year, and I think I've come to a conclusion: I wan't to build the best robot, even if that means that I don't go quite as far in the competition.
That statement may seem strange, but it might help if I give some examples:
1) In 2012, I believe that team 1717 had, by far, the best robot in the world. They had amazing capabilities, with a deadly accurate shooter and an awesome swerve system. However, they were not the world champions because there robot broke down in the field elims.
2) I don't mean to bring down the 2013 world champions but I would have much rather built 469's robot than any of the robots that won. This is because, in my mind, they built the better robot. 469's machine could play more of the game, more effectively than any of the winning robots, in my opinion.
So even though I want to win, I don't want to do it with a better implementation of the same robot that everyone else built.
(This is not to say that you have to use swerves to have the better robot; Only that I want to build the better robot, and swerves can slightly help in doing that.)
02-01-2015 17:44
Pault
Re: pic: 2015, Year of swerves?
I find it strange that people in this thread are not impressed by clean, efficient, well engineered robots. Creativity and producing the best, most capable robot design, although important, isn't always the mark of great engineering. Sometimes it is taking a fairly standard design and making it better than every other implementation. For a real life example, think about cars. Although having many features in a car is nice, what really seperates low end cars from high end cars is build quality.
So with that being said, I don't think a competitive robot can be "boring", because to me the best robots are the ones built to be the most competitive.
02-01-2015 18:25
waialua359
Re: pic: 2015, Year of swerves?
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Originally Posted by sanddrag
We've wanted to make one for probably a decade now, and still never have. We've been doing FIRST for 14 years now, we have mentors who have been doing it nearly as long, we have full in-house CNC manufacturing capabilities, machining mentors, a very well educated programming mentor from a highly-esteemed institution, and students with 3 full years experience behind them. We have the capability to build two identical robots ( and have done so twice) and access to a full size practice field.
We have downloaded and studied the CAD models of other teams' swerve drives and have twice begun modeling one of our own. We still have not built a swerve and it's not likely that we will for 2015. Why not? Years ago our team decided that we would never build a swerve drive during build season unless we'd previously done it during the offseason., and that never happened. What is our reasoning for that decision? We've determined that the marginal performance gains in the drive system do not outweigh the additional time requirements to design, fabricate, refine, and program it. That time can be spent further developing and refining other parts of the robot. And this is what frustrates me a little bit about the current state of COTS items. Years ago, teams could gain a significant advantage by heavily investing in the design, development, and manufacturing of these complex systems. Now, you're at a large disadvantage if you choose to do something custom over buying it. Why, you've lost time you literally could have bought. But buy buying it, you've lost the learning process. We're teaching students how to pick things out of a catalog (which is a great skill to have!) rather than teaching them to make the things that are in the catalogs (or better yet not in any catalogs). But, that's another discussion for another thread. Part of our "problem" is that we doall the manufacturing in house. We can't spend 4 weeks on CAD, send it out to be laser cut and bent on a CNC press brake, and get a robot back in 3 days. We don't have that kind of sponsor like some teams do. If we don't have the mill running on day 2, we don't finish. And that's with a WCD. |
a very informative and nice summary of what is probably similar to our situation. Back in 2010, we made a swerve iteration similar to that of 1983 after their 2009 robot, when they graciously shared their CAD files.
Since then, we have never gone back to designing one in the off-season, simply because of time constraints and putting it off with other areas that we try to improve or fix. This is mostly due to retiring mentors, constant change of school admin in a transient school, and other dynamic factors that affect progress.
Like you, we can build everything in-house with enough resources to build more than 1 robot year in and year out. However, we lack enough mentors to overcome the time constraints in building a practice bot. In fact, we barely have enough time to build 1 robot, using a WCD chassis. We've made gradual improvements to it the last several years and feel that the learning aspects that our students have experienced are very rewarding.
We dont have the avenues in Hawaii where we can just send out CAD's to a sponsor and make our frame in a matter of 3 days or less. In summary, this is why our setup is the way it is (doing things all in-house) with the main challenge trying to find additional mentors to help our program.
02-01-2015 20:32
matthewdenny|
Originally Posted by Pault
I find it strange that people in this thread are not impressed by clean, efficient, well engineered robots. Creativity and producing the best, most capable robot design, although important, isn't always the mark of great engineering. Sometimes it is taking a fairly standard design and making it better than every other implementation. For a real life example, think about cars. Although having many features in a car is nice, what really seperates low end cars from high end cars is build quality.
So with that being said, I don't think a competitive robot can be "boring", because to me the best robots are the ones built to be the most competitive. |
Diffrent people are inspired by different things. Do what is an inspiration to you and your team, and regardless the outcome on the field you can never lose.
05-01-2015 10:22
MrForbes
Re: pic: 2015, Year of swerves?
it's interesting that this thread disappeared before kickoff...and it turns out that the 2015 game is one that really needs swerve drive
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