Drive Systems... ...The FIRST Arms Race?
 

I know that tomorrow is ship date and this message is likely to go unheeded for at least that long, but this is an idea that has been bouncing around in the back of my mind for a while now and it is coming out now...

I have not really been on a team for 3 seasons now -- perhaps 4 depending on how you count things. From the outside looking in, I seems to me that FIRST has become an Arms Race of sorts, every year there are more and more teams with more and more motors devoted to their drive system with grippier and grippier treads.

There are a number of reasons for this trend.

• FIRST game designs have encouraged pushing matches.
• Too many motors have been introduced to the kit [1]
• The FIRST KOP transmissions have encouraged 2 Motors per side (4 motor drives)
• It has become easier and easier to implement multimotor drive systems with very grippy tires [2]

From an individual team's point of view, I can understand why teams make the choices they make. When everyone has 2 motors per side and custom made tires with super grippy tread, you have to do something extra to get an advantage, so, you put 3 or 4 motors per side and you go with even wider, grippier tires.

BUT... ...from FIRST's point of view, I think this is bad situation.

• It is harder on the field elements
• It is harder on the other robots
• It makes teams do a lot of extra work just to keep up, for limited competitive value and almost no inspirational value.
• It is no fun to watch (imho)

So, I think that something should be done about this situation.

Possible ideas:

1. Re-think the motors in the KOP -- 6 motors in the 1996 KOP may have been a bit thin, but clearly 17 in the 2007 KOP is excessive [3].
2. Limit Power to Drive system by
   1. limiting the fusing used to supply current to the drive motors. There are several variations on this idea
      1. No more than 120Amps total
      2. No more than 40Amps to drive any wheel (this would only allow 40Amp per side if you had a single chain drive all wheels per side but if you had a motor for each wheel and you had 4WD, then you could potentially ahve 80Amps per side)
   2. Intruducing a feature the the Victors that reports current back to master CPU. Have master CPU limit drive current. [4]
   3. Rate each motor for power and just put a limit on the power per wheel or the power for the total drive system (similar to limits on current via rated breaker amperage only limiting via rated motor power)
   4. Require that only unmodified (and relatively slippery) wheels of brand X be used for all robot drive systems
3. Make a simple test rig from simple pulleys, PVC pipe and dead weights that can test the pulling and pushing force developed by a robot. Limit robots pushing and pulling forces to something like 50lbs.

There are pros and cons to all the ideas. I think 2.4 would probably limit creativity too severely. From a limiting damage to the field and other robots point of view I think I prefer #3 but from an ease of implementatoin point of veiw I like 2.1 or 2.3. The more I think about 2.2 the more fun we could have with the idea (read note [4]). But it would require significant work by FIRST & IFI so I think it may be DOA.

Think about these ideas and add your own. Perhaps this is just a solution for a problem that doesn't exist.

As always, comments are welcome.

Joe J.




Notes:
[1] This year we have a record 17 motor in the kit with a total peak power of over 3000W

• (4) 2.5" CIM @ 330W
• (2) FP @ 380W
• (2) 3" CIM @ 270W
• (2) BB @ 100W
• (2) Globe @ 50W
• (2) Keyang @ 20W
• (2) Denso @ 20W
• (1) Mabuchi @ 15W (not sure if this is in the 07KOP but it is listed in the tips page)

As a point of reference, the 1996 KOP had 2 Drill motors, 4 seat motors, and a pneumatic pump with a total peak power of close to 500W (I am going from my memory so I may be slightly off).


[2] IFI sells great traction wheels, AndyMark sell great shifting transmissions and wheels and planetary gearboxes, BB and others sell great planetary gearboxes, the Nothing But Dewalt Whitepaper has made shifting CIM transmission extremely common even for rookie teams, etc.

[3] I say this as one with unclean hands. Over the years, I have played a key role in getting the following motors in the KOP:

• Delphi Window motor
• ITT Window motor
• Delphi Power Sliding Door motor
• Bosch Power Sliding Door motor
• Bosch Drill motor
• Globe Transfer Case motor
• Keyang Seat motor
• Johnson motor
• Mabuchi motor
• Taigene Power Sliding Door motor
• Fisher Price Power Wheels motor
• Chiaphua (aka Atwood) motor
• 2.5" CIM motor
• Banebots motor

[4] Perhaps this would even allow a new game twist that might make games more dramatic. During a match, each robot would have a "Energy Meter" shown on the big screen. When a robot is out of Energy, it doesn't move any more or it moves in "limp mode" where it can move but only very slowly. Perhaps robots could do things to get more energy for their robot or perhaps could win more energy for their alliance (e.g. score a tube on the high rung and you get an extra 10,000 Joules) Could be fun.

Re: Drive Systems... ...The FIRST Arms Race?
 

Re: Drive Systems... ...The FIRST Arms Race?
 

During seven years with Team #64 and the last year with Team #39 we always valued speed and agility over brute power. We never won the National Championship. This year we sold out and bought some traction wheels and still designed a robot for speed rather than push. Go figure? I guess old habits die hard! I believe Dr. Joe has a valid point and I support him!

Ken

Re: Drive Systems... ...The FIRST Arms Race?
 

remember in 1996 when you could get a top of the line video card with 8Mb of onboard ram . .

I think thats what were seeing now.

Ill explane why.
this year is my teams 2nd year. at the end of last year we looked at our drive system and said this was good but next year we want one thats just as fast but wont let people push us around. so thats what we did this year. as for next year who knows(weve already started talking about using small BB transmitions with fisher prices ).
and Im sure thats what every team does each year. sit down talk about what worked what didn't and improve.

now on to power. I personally believe that this nation(and the world for that matter) is coming to an energy problem. politics aside, predicted American Chinese and Indian energy needs will not be meet with current resources and current technology. we need to eather A) have a major oil/coal/something find in a neutral territory, B) have a major breakthrough in energy science(solar, fusion, something else), or C) become better users of what we are given.
because plans A and B are a luck of the draw thing I like plan C. and on that note I think that FIRST should implement some sort of energy efficiency in to feature games.

Re: Drive Systems... ...The FIRST Arms Race?
 

I'd like to lend my cautious approval to many of these suggestions as well. FIRST gets a lot of its appeal from the large and powerful robots that go out to compete and a lot of creativity stems from the wide range of motors available. So limits would need to be carefully thought out. But let me give a brief example from my own experience:

At MIT, sophomore Mechanical Engineering students take a class called 2.007 (formerly Prof. Flowers' 2.70), during which everyone individually builds a small robot (10 lbs, 18"x18"x24" max). So by weight, approximately a factor of 10 smaller than a FIRST-sized robot. The catch is that the whole thing must be powered by four baby Mabuchi RC-260 motors, capable of putting out no more than about 4 watts each. So by power, a factor of hundreds less than FIRST kits provide. The motors are also somewhat prone to burning up, and so particular care must be taken not to run at or near stall for extended periods of time.

I'm not saying that this necessarily turns out efficient designs (I know from taking the class that more often than not, it simply provokes endless complaints.) But the design limitation adds another dimension to the planning involved in making the robots. This year, I helped with the introduction of current sensors to the control system which can wirelessly feedback motor current data to the "OI" for use in design analysis and motor protection. We are also implementing an "energy meter," just like Dr. Joe mentioned, for fun now but it may wind up in the competition in the future.

In all, I still much prefer the ability to run motors as speed sources and know that they will supply as much torque as I want, as in many FIRST applications. But I can see how some restrictions could be beneficial in leveling the playing field and encouraging efficient design.

Re: Drive Systems... ...The FIRST Arms Race?
 

Joe,

I agree completely with what you are saying. FIRST robots have moved towards making a beefy drive train, and the end effector sometimes a 2nd thought. You need to have a drive train with super grippy wheels and 4 motors just to be COMPETITIVE. I remember (it wasnt long ago) when you put 4 motors in a drive train, you would be seriously feared.

However......
I don't think that we should cease the development of drive trains by putting barriers on power. Year after year I still get wow'ed by teams coming up with new drive trains (118 you definitely pulled that off this year) and I also get wow'ed by amazing end effectors. I agree that watching a pushing match is very boring. I feel that we are at a point where we cannot turn back and go to "the old ways", which is not what your saying, but its in the same realm of things. FIRST needs to throw us a HUGE CURVEBALL with a game. I think they tried that this year with the robots lifting robots thing, and we'll see how that plays out.

The reason drive trains are so strongly pushed for is because of how effective they can be. A solid drive train makes you competitive (theres always defense). A weak drive train (when compared to 'stronger' ones) with an amazing arm, may do well, but any solid drive train will put up a strong fight against that robot.

This most certainly is an issue, and its most certainly a sticky one. I feel some of your ideas may be a bit extreme, but some of them may be very effective (40 amps per side, 50 lbs of pushing power). Thanks for bringing this problem up Joe.

Re: Drive Systems... ...The FIRST Arms Race?
 

Maybe it is time to take the NASCAR approach and start limiting what can and cannot be done with drive systems. While multi-motor drive systems are nice, not every team has the financial or technological resources to build them. I am VERY grateful for the kit gearboxes since we are on a tight budget, but the reality it is no match against a 6 motor gearbox.

Come to think of it,FIRST, NASCAR, NHRA, etc. could form a partnerships and star some new robot related competitions! For Example;

1. NRHRA (national robot hotrod racing association) - Robot drag racing at its best (After all we already have power tool drag racing)!

2. NRTOWA (national robot tug of war association) - Two robots, one rope and one mean gearbox.

Re: Drive Systems... ...The FIRST Arms Race?
 

In hockey North American teams have traditionally produced larger, harder hitting players, while European teams have traditionally produced faster, more agile players.

Again, this is "traditionally" and "stereotypically"... one of the reasons is that the Europeans play on a larger ice surface.

Perhaps the solution is to increase the size of the field so that more agile robots can run around the push bots.

Jason

Re: Drive Systems... ...The FIRST Arms Race?
 

This may be the slight lack of sleep talking in the following post.

I honestly don't see a problem with the amount of motors in the kit as is. I don't like the idea of limiting what you can do either.

When first looking at Dr. Joe's post, what struck me was the question of innovation (the other I word) versus constraints. On the one hand, innovation can be measured by one can accomplish in limited circumstances. However, that can be decieving. For example (as Brandon mentioned earlier), team 118's drive this year is rather innovative. There were innovations back before we had this amount of motors as well. I don't know much about robot drive trains before 2003, but the TechnoKat's ball drive in 2003 sticks out in my mind. Innovation can be achieved in either way, in my opinion.

With that said, the recent drive trains COULD be considered an arms race. However, besides pushing other robots, what else could they be used for? With it so easy for a team to make a powerful drive train, perhaps it is time for FIRST to step up and make it a requirement in the game itself to have a very strong drive train (heavy game pieces, etc), which could then encourage further innovation and "raise the bar" for FIRST teams.

Re: Drive Systems... ...The FIRST Arms Race?
 

My team has been involved in First for 3 years. The last 2 years we had a robot that could push other bots out of the way and play good defense. We did fairly well (2005 we lost to the eventual nation champions in divisional semis) but we found that a highly maneuverable bot could evade us and a strong defense never won more matches than strong offense. In 2005 there was no pinning rule so every match we would score a few and pin the best opponent so he couldn't score. The only problem was we played one team (i think it was the cybersonics) and they would just roll off of us every time we pushed them. This year we made a fast agile bot, but used shifting transmissions and custom traction wheels so we should be able to win most pushing matches. I do agree that some teams are ridiculous (one team had 8 motors) but two motor drive trains are acceptable. First should not restrict energy usage because, overtime, the better style of drive train should be more common. It is not First's job to tell teams how to build their bots and what motors to use.

Re: Drive Systems... ...The FIRST Arms Race?
 

Well said Dr. Joe. I would think every person who have seen past competitions will agree with you on this matter. It's was cool and great to see new transmissions, new drive trains, but I feel we are slowly losing the the offesive side of us and focusing more on defense.

Yes, it is great to watch a robot push another one to the other side of the field (SPAM 2002 pushed SigmaC@T 2002 from one side of the field to the other, it was the coolest thing ever). But what happened in 2003? Why didn't we see many stacking bots? Why did we just see wheels on box with a monstrous drive train under it? What about 2004? There were more hangers than scorers. I love pink team and I would have liked to see them scoring balls rather than playing defense and hang. One of the pure scorer from that year was team 45 and they were on offense at time. There were more to watch in matches. Anywho, you get my point. I will talk about Team 118's robot too in here. They come up with a very beastly machine every year, but I don't think I have seen them playing defense as much. They have a beastly drive, but they only use it when they are being stopped from scoring. Oh man, you guys gave us the hardest time in 2005 on Curie.

If we were to use less motors, I believe it would give all of us a chance to look at the offesive side of the game, rather than just defense. It kind of makes me upset when I often hear, "Defense is the way to go." But at the same time I love it when I hear, "Best offense is your best defense."

Or I can see the other point of view where teams prefer to use certain motors for their applications. It would be nice to have all the motors we get, but if they were used to make more innovative machines, I would be happy. I really would like to see matches where teams compete to score, not compete to stop each other.

Re: Drive Systems... ...The FIRST Arms Race?
 

I think if you start limiting the drivetrain you'll stiffle some good innovation. The last few years of FIRST have seen a number of interesting drivetrains crop up. Drivetrains are evolving and one route has been the stronger, beefier drive trains we see today, but the agility of robots has also increased. The first holonomic drivetrains only came about a couple of years ago and already those have evolved into the now more common mecanum drives(thanks to andymark). They're stronger and more agile than their ancestor. Swerve drives have never taken off due to their complexity, but those that have been built have had enough succesful stints in the limelight that one could argue that they're better than the 6 motor monsters out on the field.

As far as brute force drivetrains go, its really only been the third year of plentiful very strong drivetrains. But even these have been evolving. Three years ago there were very few 6 wheel drive robots, last year I'm pretty sure they outnumbered 4 wheel robots. The reasons are due to IFI's traction wheels, the 4 motor kit gearbox and the "I have to use an Andymark 2 speed to remain competitive" problem. I'm not sure if those were bad influences, but they certainly accelerated the drivetrain arms race. I for one hope we never go back to 4 wheel drive, those robots were inefficient and had severe turning problems that plagued rookies and veterans alike for a decade.

What will come next I'm not sure, perhaps 118's new drivetrain is a hint as to what the future will bring, but I think its clear that drivetrains haven't stopped evolving yet. Maybe we've seen everything now, and within 2 years most teams will reach a pinnacle of strength or agility. I know that when the evolution finally stops, once teams can't get any more out of the drivetrains in 6 weeks it will be time to throw a radical curveball, but for now give it another year or two.

A couple of asides. I think an example of what we don't want FIRST to turn into is a racing league, where stiff rules make teams fight for 1% or 2% gains in their designs. Also I think this thread suffers from the chiefdelphi syndrome, which is that elite teams dominate the chiefdelphi scene. Numerous teams that aren't making 6 motor drives and beautifully machined manipulators are out there and don't post on chiefdelphi. At the same time most of the teams that would make a 6 motor drive end up showing it off on here. It doesn't change the argument, but its good to keep in mind when you consider that this arms race isn't really amongst all 2000 teams but just about 50 veterans that have the experience and resources to keep the battle raging.

Re: Drive Systems... ...The FIRST Arms Race?
 

I'm not so concerned about power in the drive. If the team builds it well and can control it on the field, what does it matter?

I'm more worried about people buying these new, off the shelf mecanum wheels and not knowing how to program for them correctly. What a waste.

Re: Drive Systems... ...The FIRST Arms Race?
 

i don't agree with this. There are members from most teams on Chief Delphi. And alot more than 50 teams are capable of producing 6 motor drives but, like my team, do not see the point. They are heavy and unnecessary. A well designed 2 motor drive will still be very competitive. Also you cannot win a match by having an amazing drivetrain. The only thing you can win from a good drive train alone is a pushing match, which FIRST doesn't awards points for. Something more important than the drivetrain is the driver because a smart driver can avoid a pushing match when possible, or knows when to shift down to push thru someone. If a team wants to spent 75% of their weight budget on a drivetrain, let them, but one of the elite teams will know that scoring is more important than pushing.

Re: Drive Systems... ...The FIRST Arms Race?
 

I completley agree with Tom on this one. There are so many of these new off the shelf parts every year, that teams see, and instantly say "Oh, thats different, lets use it, its spose to work great." When in reality they have no idea what to actually do with it. I've seen teams ruin shifters and wheels and so many objects by not knowing how to control them/program/use/install them. I would much rather see teams design their own parts, possibly using the ideas of others(granted they understand them). These companies who do mass produce these parts, should include more drawings, and more information to help teams understand the use of the parts.

Re: Drive Systems... ...The FIRST Arms Race?
 

Dr. Joe -

I definitely haven't been involved in FIRST for as long as you have, but within my scope of experience (5 years in FIRST), I disagree when you say that defense has been on the rise. Even back in 2002 (the year before I joined my team), a strong drivetrain and lots of pushing power was very important. In 2003, defense was king. Ever since 2003, I feel that defense has actually been steadily de-emphasized. In 2004, defense and offense were about equal in importance (the ideal balance in my opinion). In 2005 defense was almost completely eliminated from any place of importance. Last year, defense was slightly more emphasized, but you still couldn't win the game on defense alone. It's tough to make a call about defense this year yet, but certain rules (i.e. - you aren't allowed to de-score opposing ringers) lead me to believe that FIRST (the GDC at least) is trying to balance the forces of defense and offense (if not outright giving offensive teams the advantage).

Also, the addition of more motors to the kit does not necessarily mean that FIRST is trying to encourage a drivetrain arms race. More motors could mean more easily facilitated (and more complex) offensive arm designs as well.

I'm not going to disagree with you on your last two points, but I don't think that those two facts are necessarily a bad thing. How many teams would want to use the KOP transmissions if they felt that they would be inadequate in terms of pushing power? Correct me if I am wrong (you are probably in a better position than I to judge this), but I don't think multimotor drivetrains are any more prevalent than they were in 2003, my rookie year. I think that in encouraging teams to use 2 motor/side transmissions, FIRST is just trying to level the playing field by providing a competitive solution that is accessible to all teams.
I am unsure about your first point. I think the wear and tear on the field elements is highly dependent on the nature of the particular game. I would say that most damage to field elements are more commonly the result of intense offensive play, as opposed to defensive play. For example - the tetras in 2005 broke frequently as a result of long falls from offensive arms. Balls in 2004 were popped by grippers and claws and rollers. The 2006 balls were chewed up by shooting machines. However, one could attribute carpet damage and other field damage to defensive play. It seems to go both ways and I am not sure of the overall effects of offense vs. defense on the playing field.

As for your second point, yes, you are probably right. More defense will result in more damage to other robots. However, one could say that this encourages teams to be come up with more robust designs (a good thing, IMO. It's important to engineer robust solutions in the real world - not just elegant or showy ones).

I definitely disagree with your last two points. I really don't think it is too much extra work to design for 2 motors/side as opposed to 1. If I'm going to sit down and design a transmission, it would probably take me the same amount of time regardless of how many motors I wanted to use. Plus, the 2 motor solution is easily facilitated by the KOP (or at least it was in 2005 and 2006).

My main disagreement, however, is with the statement "limited competitive and inspirational value." Innovative drivetrains have certainly shown their value in competition. On my old team, 716 (and many other teams, I'm sure), the drivetrain was always placed at the very top of our priority list. We knew that we would not be able to do anything effectively if our drive system could not meet our needs. For example, we decided that we wanted 2 speeds so that we could play defense effectively, but still be fast enough to move around the field and complete our offensive tasks. This meant that we needed to design and manufacture our own custom transmissions.

How is it less inspirational to design a custom transmission than to design an end effector? How is it less inspirational to design and manufacture a mecanum wheel than to design a turret? I think any design project like this is a beneficial experience to the students on the team. It doesn't matter whether it's a part of the drivetrain or a part of the arm; as long as the students see the end result of their work, both are inspirational. Just look through the pictures on CD media tagged with "drivetrain", "wheel", and "transmission", and try to tell me that there is no innovation occurring within those disciplines!

Also, I think that defense is a very important and necessary part of the game (strategically and in terms of its "interestingness"). However, I do believe in a balance between the two elements. In the perfect game, an excellent offensive team should be able to beat an average defensive team, and an excellent defensive team should be able to beat an average offensive team. 2004 was the perfect example of a "balanced" game - good defense AND good offense could win a match. In 2003, the scales were tipped too much in favor of the defensive teams; conversely, in 2005 the scales were tipped too much in favor of the offensive teams.

On a side note, how can anyone say that defensive play is boring to watch? I will never forget the 2004 finals and semi-finals on Archimedes when my team, 716, was faced off against some of the strongest defensive (as well as offensive) bots in the world! That defense was some of the most intense (and visually and emotionally awesome!) that I have ever seen (494, you are amazing). It was heart pounding and exhilarating - I wouldn't ever want to trade that for a technically interesting, but rather boring exhibition of robots that are just scoring (and no one is trying to prevent them from doing so). The presence of defense makes it even more amazing to see high-scoring robots perform - knowing that they are experiencing difficulty, yet are still able to overcome!

Definitely do not impose limits on the amount of power in the drive system. As it is right now, the amount of power a team can have is already somewhat limited by their coefficient of friction against the ground, so potential power is not infinite (after a certain point, the wheels will just begin to spin against the carpet in a pushing match). Yes, the extra power will help in acceleration, but there comes a time when too many motors becomes more costly in terms of its draw on the battery (and less motors available for other manipulators) than it is worth. I don't fear that defense will intensify in the likes of an "arms race" for these reasons (as well as the fact that it's obviously not being encouraged by the GDC). Also, it would be costly in terms of battery power to use ALL of the motors in the KOP. Thus, teams will have to learn about restraint in their designs and make responsible choices about motor selection.

Thanks Dr. Joe for bringing up this discussion. It's very interesting, and I hope I don't sound as if I am being argumentative. Just trying to share my two cents! You definitely have a much greater perspective on the evolution of FIRST than I have.

-- Jaine

Re: Drive Systems... ...The FIRST Arms Race?
 

This is a real issue. This year, our drive system was biased towards going off-the-shelf when possible. The result was a 6WD with Gen2 AndyMarks. Works beautifully.

Overall, I agree with most of the points raised in the thread. However, I think the solution isn't so much in meters and lines on the inspection checklist. The solution seems two-pronged to me.

1) Cut down on some of the drive-grade motors, and perhaps work in some more arm-friendly motors. Drop a couple of the Big Powerful Motors (herein defined as the CIMs, big and small, and the F-P), either individually or in pairs, and throw in a couple more window motors. I mean, sure you can do window motor drive, but most teams will just work with less power there.

2) Create game objectives that value finesse and agility over pure brute force. Rack 'N Roll, Triple Play, and (to an extent) FIRST Frenzy can arguably meet this criteria. Aim High, Stack Attack, and Zone Zeal couldn't to the same degree. Make it so we've got to move fast to score well, and we'll do it.

Re: Drive Systems... ...The FIRST Arms Race?
 

I disagree with you about Rank 'N Roll encouraging a maneuverable drive train. If you don't have the stickiness and the power to stay put when someone is trying to push you this year, you will have no chance of being able to score a tube. precision manipulation with an arm requires a stable base, and if a team is trying to nudge you, they probably will be able to.

I want to see games with more variety and strategic possibilities. I think adding the three different weight classes of robots this year was a really interesting idea. What if they took the idea even further and limited classes even more? We might see even more innovation and teams working to fill specialized niches, as in the 2004 game. The past three years there has been a single viable objective for teams. This year starts to change that a bit with the idea of a "carrier robot", but there really isn't enough differentiation.

Force teams to do something other than push hard and do one thing well.

Re: Drive Systems... ...The FIRST Arms Race?
 

Greg, I gotta disagree with you on the weight class idea. They are going in the right direction, but I think they need a different type of variance. I really dont see alot of designs changing drastically do to this rule.
Raising the Bar, in my opinion, is the best game FIRST has had. It had alot of variance. You could be a ball manipulator or you could hang, or you could do both. In recent years, you basically had to make an arm or make a shooter. There really weren't multiple options. FIRST needs to concentrate more on making those options available. They don't need to have different shaped game pieces (that might make it too difficult), but they need many more options. This year, you dont have much to choose from.

Re: Drive Systems... ...The FIRST Arms Race?
 

I really appreciate everyone's very thoughtful comments. It was much much more response than I ever expected on the day before shipping.

I just want to make 2 points:

#1 I never even used the word "defense" in my posting. I am not against defense and that was not the point of my post.

#2 I misstated my point when I said "It makes teams do a lot of extra work just to keep up, for limited competitive value and almost no inspirational value." I SHOULD have put in there "almost no additional inspirational value"

Trust me, I am a HUGE believer in the inspirational value of drive trains. Building & competing with remote control machines that can DRIVE is a fundamental ingredient that makes FIRST work. My point is just that I don't believe that having the average number of drive train motors climb from 2 to 4 to 6 to 16 is really a good investment in terms of the added inspiration for the extra effort expended.

Joe J.

Re: Drive Systems... ...The FIRST Arms Race?
 

I personally believe that the issue lies in the lack of creativity required to move about the field. This comes from the flat fields that we have seen in recent years. Think of AIM high; an entirely flat and open fields. Yet if you look at previous year's fields, there have been midfield ramps, gates, giant teeter-totters, steps, and other elements that encouraged creative drive systems.

We can look at the common drive systems that we have been seeing lately, it is clear that the field has required nothing more than a high torque box on wheels. If FIRST were to bring back complex fields, we would see more innovation, and teams steering away from massive pushing machines, as they would be forced to use the weight more conservatively to achieve motion.

[side note: My personal idea for a challenging field would be a steel piping grid, suspended about 12 feet above the field. Bonus points would be given to teams that could play the game without touching the ground throughout the match. Even more points would be given out to teams that could intentionally change from driving to hanging based on phases of the game]

Re: Drive Systems... ...The FIRST Arms Race?
 

Monkey-bar robots would be cool.
:cool:

Re: Drive Systems... ...The FIRST Arms Race?
 

I like the idea of NASCAR robot racing...

I agree... it seems the team with the most motors and biggest corporations
seem to have any edge. Maybe the time had come to set limits (hello restricter plates).

I've a friend in Levle Cross that's really into NASCAR. He's told me and showed me some of the tricks the race team would try to get an edge or bend a rule to its limit. Back in his day #43 was a real threat on the track.
Some of their trick really took some smart engineering.
I could see teams trying some tricky engineering here too but maybe we're getting away from what FIRST is... the robots and the games are third...

Learning to work together as a team, making friends, and learning how to deal with deadlines , problems, and challenges should be second.

Learning how to think, how to deal with people, how to lead, and learning if you set your mind to it and apply yourself, anything is possible should be first and foremost. IMHO

Re: Drive Systems... ...The FIRST Arms Race?
 

If memory serves me right... QC Elite has 6 motors in the drivetrain, and 4 on the arm. Ten motors all together. Super agile robot and a little bit of pushing power. Four inch IFI traction wheels, also.

This is the first year we've implemented more than 4 motors in the drivetrain.

Does anyone remember the first crab steer systems? Did they have a million motors?

Re: Drive Systems... ...The FIRST Arms Race?
 

Don't you think though that this situation that you are commenting on is a trade off that is directly linked to the game given by FIRST. The games recently haven't been incredibly complex in the ways of scoring so teams have the extra weight to spend on large powerful drive trains. I agree that we have probably have more motors than needed, but I also see more and more drive trains becoming lighter and lighter as people experiment with different materials so they have the weight for those motors.

How about weight classes for motors, which make a harder tradeoff rather than just height....maybe 5lbs less for each motor powering the drive train above two?

Also, even though carpet is a great, readily transportable item that is available all over, maybe it is a time for a change, that has been a constant for a lot of years....what about something like the safety squares that they sell (pictured beneath 27) http://www.chiefdelphi.com/media/photos/20302

Re: Drive Systems... ...The FIRST Arms Race?
 

If we're still trying to gain traction in a market that is going to take a very long while to warm back up to competitive robotics, we need to keep growing. Defense and pushing is a very viable tool for growth. And, it's not like we're stuck with the same format every year - the game does change.

Go ahead, make the game more conducive to using those motors in other places. But don't restrict their use. It's the best tool we have.

Re: Drive Systems... ...The FIRST Arms Race?
 

Team 148 had a drive train for Toroid Terror in 1997 that they could turn sideways and spin the goal tree after docking with it. It wasn't exactly swerve, but it was a close cousin.

Team 47 had Swerve on its 1998 robot for Ladder Logic*.

Going from memory that year there were 2 drill motors, 2 Seat Motors, 2 window motors and 2 Delphi Power Sliding Door motor.

Joe J.
*We won 3 regionals that year and were very competitive at the Championships. That was the last year that they had 1-on-1-on-1 game format with seeding on Friday and a Double Elimination tourney with everyone in it on Saturday. For those who where there they probably remember it as the year with the Looser's Bracket from Hell. There were about 10 really great teams that ended up in the Looser's Bracket and only one was getting out to the semi-final round. I think it ended up being the TechnoKats and they went on to win it all that year.

As another aside, Raul-the-Magnificent and the rest of the Wildstang crew probably recall it has the year of the Egg Shaped Ball that cost them a National Title. They had their patented suction ball holder protecting that 1 ball they had on the Ladder with a bunch of doublers in the middle goal. The only the Egg Shaped Ball wasn't touching both rails!!! Into the Looser's Bracket from Hell they went...

Re: Drive Systems... ...The FIRST Arms Race?
 

Arms Race? What arms race?

Re: Drive Systems... ...The FIRST Arms Race?
 

I like this idea. Maybe set it up to encourage an efficient drive. I'm sure there's lots of good ways to do it...

But I like this idea alot. I think alot of teams put time, weight, and MONEY into drives just to survive the matches. I think it just drives the cost up. And alot of teams just go out and buy solutions to the 4 motor drive.

Where do I sign the petition?

Re: Drive Systems... ...The FIRST Arms Race?
 

Too many motors in the kit? bah. We're using 5 this year. Time will tell if we are good in 07 or not. Comparing what I see now with how we have stacked up over the last 10 years, I like our chances.

Each year, you can find teams with simple designs and low amounts of motors winning matches consistently.

More motors = designs that try to do it all = difficult to control robots = lost matches = frustration.

Sure, FIRST gave teams 16 motors in the kit. I agree it is too much, but for a different reason. If a team is silly enough to use them all, then they have other problems that will bog them down for the season (too heavy, lack of control, etc.)

Best of luck to all,
Andy B.

Re: Drive Systems... ...The FIRST Arms Race?
 

Hmmmmm, I have a few thoughts here:

1. Lots of motors in the kit means cool off season projects for many teams who can't afford extra purchases. They also mean spares for swapping the FIRST way. It certainly adds to the whole power budget decision-making thing too which is a challenge in itself.

2. I don't know about too much drive train or restricting use at all. Last year I had a rookie team that used a grand total of five motors and was pretty competitive by the off season once the bugs got worked out. This year the team is up to seven motors and that was a stretch for us. Do I feel we will be less competitive than those with custom or expensive gearboxes? No.

3. I'm all for any motors in the kit we can get. Doesn't each motor represent one more potential supplier? Isn't that one way FIRST grows? How can you ask a supplier to donate a ton of stuff then tell the teams that they can only use the motor for certain applications? Doesn't that squelch creativity and discourage potential suppliers?

4. Why are people still talking about aftermarket gearboxes in a negative way? Hasn't that been done to death? More competitive, moving robots means a higher level of exposure to the public means we are closer to achieving FIRSTs real mission. How is that bad? Without the AndyMark single speeds my rookie is using, they'd be carrying open transmissions to a regional waiting on new plates.

5. With all due respect, how can anyone equate or value levels of "inspiration" by what motors are in the kit? The inspiration comes from the interaction between students and mentors, teammates, and interaction with other teams. The tools one uses to inspire an individual is up to the "teacher".

I'm glad we have so many technically inclined folks that help the program move forward, I honestly do, but if we get tied up in kit analysis we might forget there's a student that needs our attention.

Namaste...

Re: Drive Systems... ...The FIRST Arms Race?
 

one thing that has not been brought up, which i'm probably going to get hounded for on two counts, more on that in a few. one way to limit extremely powerful drive trains would be to go to a smaller battery, one that would need to be conserved to make it through a match, so you could go for a powerful drive train for a short period of time, or a less powerful one for a longer amount of time, perhaps extending the matches so that this became a factor more. I think the innovation that would result could be very interesting to watch. Now, the two counts on which i'll be hounded, 1. FIRST just changed the battery, so for those teams that have purchased multiple for extras, this wouldn't be too nice, and the second point, many people, including me, don't like to change the battery every two minutes during testing... we have some '05 batteries that have been through competition twice, and two off seasons, and last for about two minutes before being useless, with lower powered batteries, this would become a reality even when the batteries were new, anyway, thats just my $.02

Re: Drive Systems... ...The FIRST Arms Race?
 

The Tim Allen mentality is what I think Joe is referring to. " More Power". During the off season it seams that most teams that were doing off season projects focused on drive trains. How many teams worked on manipulator development, sensor integration, or autonomous navigation? First could control the drive train arms race with a very simple rule. Limit the energy, Make it precious and expensive. ( like what is happening in the real world). Each team is allowed 2 batteries at the competition. On practice day each team submits 2 batteries at inspection and their serial number is recorded and a permanent label is affixed. Those are the only 2 batteries allowed for the entire competition. Teams can do what ever they what with the motors and mechanisms, but the energy budget is limited. If a team gets to the finals and is forced to compete with dead batteries then they pay the price for poor energy management. This generation of kids will have to face the looming energy challenges in their life time. First can help focus them on this social issue. The other way to take the focus away from the arms race is to make the autonomous period longer and more important.

Re: Drive Systems... ...The FIRST Arms Race?
 

Just a couple of thoughts -
I believe that some parts of the robot are designed to meet the specifics of the game or the playing field. The reality is, that the drive systems can almost always be re-used from year to year, while end effectors almost always cannot.

Therefore, many of the off season and season2season improvements are focused on the drive system. With an unlimited supply of motors and alot of time - it is natural for this to happen. I'm actually surprised that nobody has developed a drive system using every motor in the kit.

I like some of the suggestions that Joe has made. Yet, I also like the increased variety and number of motors to choose from.

I think encouraging the management of power could be as much a challenge as managing size and weight. Learning to understand and deal with all of the challenges, could be very Inspirational (it simply depends on it is approached).

Alot depends on where you want to focus your attention on, and where you can save time and energy by re-using what has been proven out already.

My favorite suggestion to rebalance the reuse and elevated effort for more and more powerful drive systems, is to change the playing field such that the drive system contact surface is either slippery or moves under load. Do they make portable flooring for ice covered surfaces!

Great discussion

Re: Drive Systems... ...The FIRST Arms Race?
 

We learned our lesson on this last year. Too many motors on the robot meant not enough power. We made a solid run at Nationals but battery power was a constant issue.

Ironically we had only a 2 motor drive base. I felt we were penalized for focusing on an elegant shooter because we were routinely disturbed by box bots. :(

I agree with Dr. Joe that something needs to be done. I was around in '96 and had the pleasure of building a squat little 70lbs. bot. It was a blast. I remember how challenging it was to utilize the available motors.

Pneumatics were also a rich source of power......I'd argue that nowadays they're more or less irrelevant. We haven't been able to justify the weight for three seasons.(which by the way is a product of so many motors. why waste weight on a pump, spikes, and solenoids when you have a plethora of light high torque motors to use.)

I'll never suggest that we use rules to govern how robots are built. I feel that we have too many rules as it is. Perhaps a robot class system is what we need. A stock class for entry level players and an unlimited class for the big dogs.

Teams who chose could compete in a stock class for a year or two with more access to off-the-shelf components and rules that forced them to run a stock chassis.....thus forcing them to focus on the creative portions of the game. The next year they could register to play in the unlimited class where they would have less access to off-the-shelf parts...forcing teams to go custom. Pair this system with challenging playing fields that demand creativity and we're good to go.

Many of these issues stem from the fact that veteran teams have a potential advantage over enrty-level programs from experience alone. FIRST polices it by giving young teams access to veteran team technology and dumbing down the playing field. Perhaps a class system would solve all of these problems.

Afterall, it isn't inspiring for my students to build an amazing machine just to see it bashed and beaten apart in a free-for-all melee. For the record, we jumped back on board this season with a 4 motor shifting drivetrain and tank like construction.

Thanks for your valued input Dr. Joe.

Re: Drive Systems... ...The FIRST Arms Race?
 

Funny you should mention this, the new batteries this year have a significantly lower short current (90A) than the old batteries (240?A).

Re: Drive Systems... ...The FIRST Arms Race?
 

Darn you beat us. We have 6.

I think the drive train arms race stems from a few factors I haven't seen mentioned yet. Simply every year you have to have a drive train. Therefore when teams do offseason development projects it winds up being the obvious choice because you'll be able to use some portion of the project the next season no matter what.

Another factor that caused the development of these drives in the first place was the weight of the goals in 2001 & 2002 that teams needed to move. That was followed by a completely defensive 2003 game (I blame this squarely on the ramp bonus being too high) where teams had to push to be king of the hill. Teams that were around in those years had to build stout drivetrains and didn't want to give them up once they got used to the speed and power. New teams would see these drivetrains and emulate them getting us to where we are.

Oh and there's the fact robots can weigh about 20 lbs more (bumpers & battery rule changes) now than they did 2004.

My solution for the last couple seasons has been go smaller and lighter to get away from these issues, but every time I've brought it up people seem violently against it because they don't want to give up what they've got. We've grown to expect more in the kit every year without having to give anything back, and that attitude needs to change for anything to happen in this arena.

Pete

Re: Drive Systems... ...The FIRST Arms Race?
 

We're using three motors and two cylinders. Hopefully it will be enough. We could add two more CIMs to the drivetrain if needed -- maybe.

Re: Drive Systems... ...The FIRST Arms Race?
 

While I agree there is most definitely an "Arms Race" occuring in FIRST's drivetrains (as well as just about every aspect of the robot, more on that later), I think the game becoming more defensive is a myth (again, more on this later).
I believe the drivetrain escalation can be traced to a single moment, or rather a single game, in FIRST history. 2002, Zone Zeal. While certain factors emerged earlier, especially with the creation of alliances in 1999, 2002 began the un-reversable development of this "arms race". Zone Zeal was a game based almost entirely on [mobile] goal procurement, control, and placment (tasks heavily dependent on the drive). Not surprisingly, the fastest and strongest bots accounted for a majority of the victories. This is perhaps best demonstrated by the legendary drivetrain of Team Hammond that year. 71 produced what is widely regarded as the strongest drivetrain in FIRST history (capable of towing itself, 3 quite heavy mobile goals, and multiple opposing robots on it's slow march across the field), and it capped it's domination with a win at the 2002 Nationals. Not surprisingly, we also saw the first backlash aginst power in 2002, as FIRST also saw the creation of it's first holonomic drive. 857's killough drive made monumental splashes in the FIRST community in the years to come, in part, leading to the massive amount of Mecanum drives revealed for this years game.
The arms race is without a doubt here, but more defensive games, I'd couldn't disagree more. Early in the build season, I decided to drag up some old Torroid Terror (1997) tapes to watch the last game using inner tubes. What I saw was a very defensive game (for the most part), with only a very few elite teams who could produce significant offense. Even the human players got in on the defensive action, as they threw tubes to try and knock tubes out of opposing robot's graspers. It was especially surprising considering the game was 1v1v1, so placing a defensive commitment on one team, allowed the other to pretty much have a free chance to score...but it didn't matter, defense was common. In 1998 there was even a match where the placebo won (each team started with some balls in the goals. The two competiting bots descored eachothers, and never scored, leaving the placebo's starting points enough to win the match). The same can be said for even earlier FIRST games as well. In 1993, one bot would detach what was essentially a wall that would sit in front of the goal. That factor has applied to every game in FIRST (aside of the 4v0 2001 game). What has happened was the creation of alliances in 1999, and the change to 3-team alliances in 2005. Both of these allowed for the evolution and creation of "niche" bots. These "niche" bots fill very specialized and specific roles within alliances, and defense is one of those such roles. During the pre-alliance era, it was impossible to win a match on defense alone (aside of 1998, where each alliance started with 6 points from balls located in the troughs at the beginning of the match), but now an individual team within an alliance can focus on defense and let other bots do the scoring. Games are no more defensive than ever, teams are just being more physical.
I don't see this drivetrain race as a bad thing, in fact I enjoy it. It's not unique to the drives either. Teams are making more complex turrets with greater degrees of rotation, longer arms with more joints, more efficient end-effectors, lighter and lighter components, and more advanced coding based in greater sensor input than ever before. FIRST is growing in terms of what teams can do, and the amount of teams. As the amount of teams grow, and the amount of experience expands, innovation and improvement become essential to be competitive. And none of this "arms race" stifles innovation. Just check out 1857's "spine" manipulator.
I agree that we probably get a few too many motors in the Kit of Parts (I think 11-12 should be more than any team needs). 116 is only using 6 motors this year, and 4 of the so-called "powerful" motors are sitting in our shop while the robot is on it's journey to Richmond.

Re: Drive Systems... ...The FIRST Arms Race?
 

I don't believe we should limit the battery. I have enough trouble finding a charged battery to put into the bot before a match anyway, and last year we had 6 of them circulating.

I don't believe we should limit the number of motors, either. This year we have two motors on our robot (4, counting shifting servos). While we didn't use them, its nice to know that we could if we ever wanted to.

I don't think we should limit "energy". That would make for a lot of matches with robots sitting there energy-less and cold.

I don't think we should impliment anything beyond the current limitations:
-We have Six weeks to build a robot.
-It has to be under 120 lbs.
-It has to fit into a relatively small size envelope.
-It has to use only one relatively small battery.
-we have to limit ourselves to the motors given in the kit (while there are a lot of 'em, they are not all "quality" motors)

^That is a lot of limitations already, why add more?


While defense may be seen as the thorn in an "elite" team's foot... It is the only thing possible for some teams.

Not all teams can build a manipulator that can score consistently.

Not all teams can build a functional ramp.

Defense is for the teams that can't do those things; it is the only way for some rookie teams to remain competitive. It is a way to fight back against the ever-growing population of teams that can create scoring monsters. It is the always attainable aspect in any years game that make FIRST fun for everyone involved and not just the "elites", and it adds one more task for the "elites" to design around.

And the issue with Defense making for less interesting game-play? I don't think it has much bearing at all. There was nothing more exciting than watching an offensive bot sink 4 balls last year, and then shoot the rest into a wall because they were pushed by a rookie bot, or watching an offensive bot be pushed all the way across the field by a defensive bot.


Just some thoughts,

-Cody C

Re: Drive Systems... ...The FIRST Arms Race?
 

FIRST has stepped up the competition over the years, obviously. Robots are getting more complex, faster, and more powerful. This brings the demand for new motors, and more of them. However, I like to think of the motors in the kit like a set of watercolors, with the robot being the canvas. Just like artists don't use every single color availible, robots shouldn't need to use every motor given to them. It's quality, not quantity, for some teams that is, anyway.

On the other hand, some teams have the knowledge, resources, and man-power to implement every single thing given to them, which is how I think it should be, to an extent that is. Figuring a way to use less motors to do the same task makes things much simpler and easier to accomplish in a 6 week period. However, theres nothing wrong with modifying a tried and true design with more motors to make it more powerful (like a gearbox), thus, putting you ahead from other teams. After all, this is a competition.

Re: Drive Systems... ...The FIRST Arms Race?
 

I feel From what i have seen over the years is technology of the robots has gone up alot from 2000 to now. i feel that the biggest change in First history would be the change in 2005 with the 3 on 3, this change to add another partner, gave teams a chance to be carried. plus you had more to worry about with 3 other robots to face and along with 2 other robots to not crash into. also the games have been more thinking about what other teams are going to do besides playing your own game. the Drive trains will get better and stronger and along more robust. my ideas with companies that offer some premade gearboxes, or wheels helps out teams that don't have enough money or have a lack of engineering support. i know from this year we lost our sponor and the engineering to go with the company and Andymark gearboxes helped us when the banebot plates started to warp on us.

Re: Drive Systems... ...The FIRST Arms Race?
 

The way i see it, the mathematical limits to your pushing power are all that FIRST needs. Seeing as your pushing force is only created by the force of friction, you can do two things to increase your pushing power, assuming you have used sufficient motors and gear ratios. Increase your normal force (weight) and increase your coefficient of friction (tread). In theory, the only thing that matters is the type of tread and not the suface area, but in practice a large surface area is at least slightly better. As you increase the suface area of the tread, you make it harder and harder to turn, untill you reach the point where you need some sort of actuation to reduce surface area for turing purposes, or you just cant turn at all. A robot that cant turn or that has significant trouble turning is about as useful on defense as a rock, assuming that there are multiple positons that it is possible to score from.

If you didint feel like reading the giant paragraph above, to summarize:
The limits on total weight and the fact that you cant have infinitley sticky or infinitely big tread limit robot pushing power enough, there is no need for FIRST to do anything.

Re: Drive Systems... ...The FIRST Arms Race?
 

Maybe if you knew your battery wasn't as strong as years prior, you wouldn't design your strategy and robot around stalling a few 350 Watt motors while trying to "push" other robots for the entire match.

Re: Drive Systems... ...The FIRST Arms Race?
 

I don't agree at all about having fewer motors. Though I do agree that drivetrains have become more complex, the KOP has done what it's supposed to do: give every team an opportunity to build a DRIVEABLE robot. I remember hearing from 2003 about how poorly and flimsily our robot drove. The KOP has been the great equalizer. The inclusion of links and other stuff to omni-wheels has given more teams the chance to compete at the same level.

Is there going to be a drive race? Yes. But what do I think?

I think that too MANY motors can lead to too many problems should something go wrong. And pushing well is not necessarily about how many motors are in the robot. It's about traction and control. As for leaving the 17 motors, I would add more. Remember, Dean Kamen intended for there to be too many parts so teams would have to make ENGINEERING decisions on motors.

Re: Drive Systems... ...The FIRST Arms Race?
 

I agree. I think that there has been a trend toward a more-pushing style of play, and it has contributed to more powerful drives. But the reasons for it - and the solutions - could be addressed in a different way.

I think the number one factor determining how we play the game is the game design. Not the kit, and not the robot rules. If the game design enables teams to do nothing but push others around and still be "successful," then teams will do it. This has been the case in the last few years (and probably this year too).

If the game design has a valuable feature that only requires robots to deliver in the last 15 seconds of the match, my guess is that teams who optimize for those 15 seconds are going to have some time on their hands to go stir up some trouble for the remaining 2 minutes.... IMHO, this feature of the game has nothing to do with how many motors we get.

If the game design has some really important yet difficult feature, you know, something crazy like shootin' balls through a hole at 30 feet, and many teams say that task is too much to handle, I think its highly likely that they are instead going to play some D on the teams that do shoot well.

Don't get me wrong, the robot rules have an impact. For example, the near-mandate for bumpers has, in my opinion, encouraged teams to ram into each other because now its "safe." Maybe the rules and refs should just say "don't ram into each other."

The kit has an impact too. When teams get a kit part that works great, they'll use it.

Maybe its better to use the game design, and not the kit+robotrules, to steer the horde of us robot-builders. I would rather be amazed by some creative games and designs than be forced to see lookalike robots from every part of the country (oops world). I think its more interesting and inspiring. So, let us use our motors freely, with lots of current, efficient transfer of power, and some serious traction. Then give us a game that makes our preconceived notions obselete :).

I remember going to Houston in 1998 and seeing a bot that could move sideways. Talk about inspiring.....

Re: Drive Systems... ...The FIRST Arms Race?
 

With no disrespect meant to anyone, I think we have enough limits put on us. They tell us exactly how to do everything. If they now tell us exactly how to build our drive train with the exact gear ratios and the exact wheels and the exact motors, and the exact metal to use, and the exact shaft to use, then we will have no creativity left.

I also disagree on the part that FIRST is encouraging pushing and shoving matches. They have told us exactly when we can push in and pin in the rules book. I think they want to see teams become creative with mechanisms to cap the rack.

I do agree that they gave us too many motors, but I still think its good. Anyone who decides to put them all on their robot is going to have a tough time on the field. There isn't a strong enough battery and the most robots wont even have enough weight for it. The game demands for these options, though.

Re: Drive Systems... ...The FIRST Arms Race?
 

Dont forget motors weight alot. So sure put 8 motors on your drive.

Re: Drive Systems... ...The FIRST Arms Race?
 

We have...:D

Re: Drive Systems... ...The FIRST Arms Race?
 

Yes, there has been an increase in the number of motors used on drive trains. But, the weight constraint keeps the robots’ pushing power in check. The grippiness of the tread available to us is currently limited, and with a maximum weight of about 148 lbs, a robot’s pushing force is bounded. With a shifting gear box, and proper ratios, the 4 small CIMs allow robots to have enough torque to spin their wheels against a wall, so the motors’ power is not the limiting factor.
Sure we might be able to slip the wheels faster, but a robot must be controllable, so the speed is limited too. And with shifting gearboxes becoming more accessible, there isn’t much reason to slip your wheels at 15 ft/sec. So, although there has been a Drive System Arms Race, other physical factors keep it in check.

Also, another potential solution is to limit the number of powerful motors (motors above 100W). The 2.5” CIMs, 3” CIMs, and FP motors make up ~85% of the total motor power. If, for instance, we only had the 4 small CIMs and then many less powerful motors, teams that want to get ahead in the FIRST Arms Race would have to slap on six extra motors instead of just two FP or two large CIMs.
I don’t know about all designs, but based on my experience I don’t think many other components require the power that a solid drive system does (except, perhaps, last year’s shooters), and we have pneumatics we can use. I really like the banebot motors, because they should be powerful enough for most arm/fork lifts, yet it would take three banebot motors to equal one CIM on a drive system, which just isn’t that practical for most teams.

Re: Drive Systems... ...The FIRST Arms Race?
 

With FIRST crack down on weight this year I believe that the drive trains will be turning to less and less motors but with more and more design put inot making them more efficient.
This year we have a ver nice Drive train, it's accully a BEAST and was build with 2 speeds in, but we removed the faster one for weight reasons, and we bend a battery bolder when doing 360's with it, just from the centripital force >.>

Re: Drive Systems... ...The FIRST Arms Race?
 

Bigger, badder drivetrains will only get you so far in the world of FIRST. The best and most successful robots are those who innovate and design conservatively. The best teams are those who understand their robot inside out, and understand design limitations and design advantages. In other words, the teams that have a knowledge of what they are doing are in my mind the best teams.

This year our drivetrain is using two large CIM motors. And they do just fine, working great with our custom transmission. I will definately say that our drivetrain is modest compared to other, but mechanically it works, and that is key. I have seen many other teams with outrageous transmissions that are being pushed to (and sometimes beyond) their limits. Mentioned before, defense will only get you so far. Last year at SVR a student said something that I will always remember, that " defense doesn't show up on rankings". Teams that score point will always move the crowd.

I believe that FIRST includes too many motors. Really, 4 CIMs is really unecessary, as they simply seem to encourage teams to use them in tandem and the two large CIM minibike motors. I think FIRST should eliminate some of these drivetrain motors. My suggestion to encourage creative design is to change the rules to allow teams to dissasemble the window motors to use their electric motors, while at the same time allowing only two small CIMs and two large minibike CIMs for the robot.

I also want FIRST to bring back great games like 2004 and before. From waht I have heard, I missed out on the greatest game ever played, and from 2005 till today the field has been pretty much the same. I want FIRST to go back to having more obsacles and game pieces so that teams must dedicate themselves to specific tasks. This year I have seen FIRST make a move toward this, as teams are making hard choices in going with ramps, arms, or a combination of both. So I like where FIRST seems to be headed.

Re: Drive Systems... ...The FIRST Arms Race?
 

After thinking a while on this topic, I've decided to come back and offer another view. It might have been said already, and if so I apologize for restatement.

FIRST is giving us tools to deal with engineering issues in the real world. In the real world, there are no motor number constraints on an issue. If a problem needs 10, or even 15 motors to create a solution, the engineeris will add just that many motors. So I don't see the arms race as that much of an issue. Sure, more tourque helps. But you will find the teams that do the best have the simplest drive systems, and instead have poured their focus into the manipulators.

All in all, what my slightly mangled logic (I need sleep, and breaking a caffeine addiction isn't helping) is trying to say is that we're preparing for the real world, and so limiting something as trivial as motor quantities makes little to no sense. Instead, teams should be given too many options, and should have to sort through the possibilities, in order to learn about simplicity and design elegance, rather than just shoving as many motors onto the system.

[/soapbox]

Re: Drive Systems... ...The FIRST Arms Race?
 

You just stamped in the point I spent way too many characters trying to make! Go C7H10O4N4!!!

Re: Drive Systems... ...The FIRST Arms Race?
 

I understand exactly what you are saying with this and how much work is done off season (if any at all) on the base, but the thing everyone is missing out on is the fact that the manipulator and autonomous modes and other things change EVERY year and that certain subgroups on your team have a "static" position, meaning they have to think and come up with something completely new, while others just innovate older designs et cetera. That is why the BASE or DRIVE SYSTEM of teams is becoming more and more interesting every year from what I have seen on the forums (including archives) because the base usually stays constant or at least the framework or principles of it does.

I think the energy rule is limiting just as how you choose your motors because if you are limiting energy than you are saying you have to cut power from "A" and add it to "B" and that is similar to saying you can only use "N" amount of motors out of the number given for a certain operation (drive train, manipulation, et cetera).

Pavan.

Re: Drive Systems... ...The FIRST Arms Race?
 

Yeah, I completely agree - it's difficult to do some of the work with Autonomous robots and sensor manipulation because it does change so rapidly from season to season, and it also depends upon the game as to whether it makes sense to invest the time in the technology. Take this year's game for instance, there is very little need for an accelerometer and/or a gyroscope - while some teams may take advantage of them to help them with some of their autonomous actions, the green light and the camera are all you really need to create an effective autonomous (some would argue that gear tooth sensors are all you need, but I digress). This year's game also didn't really need those sensors for in-game use, so for the most part they were played with and then set aside.

A lot of the responsibility for getting teams involved with the more advanced control system design is in the Game Design Committee. If they came up with a game that relied heavily on a particular type of sensor (or sensor fusion) then teams would embrace it. For instance the camera was a huge part of last year's game, the accelerometers were huge the year they had teeter-totters, and this year you've got ... nothing, really. I mean, you have 2 light sources which allows you to play with tracking/identifying multiple lights, but it isn't even mildly critical to the success of a robot. As far as I'm concerned the only "cool thing" they brought out this year was the lifting of the robots, and that doesn't even impact my controls team... though I must admit we did use the extra time this year to have a little bit more fun with our control system!

-Danny

Re: Drive Systems... ...The FIRST Arms Race?
 

Danny, I couldn't disagree with you more. Sensors will be vital during all phases of the game this year. Especially when trying to acquire and place tubes on the far side of the rack, sensor aided systems are going to be a huge advantage. 116 is using more sensors on our robot, particularly our maniuplator, than we ever have (at least to my knowledge). A total of 10 sensors may see use during our matches this year, and most will still be used during teleoperated mode. At one point we may even have automatic alignment software fully functional, so that we can align directly with a spider foot on the far side of the rack.
Sensor integration and navigation software are aspects that can be worked with over the summer to a certain degree, but not nearly to the extent as drivetrains. Because we don't know if we're going to have the camera, or an IR beacon, or any other kind of "target" next year, certain sensor specifics are really a risk to spend a lot of time developing during the off-season. Same with certain navigation frameworks (this year having a field element that changes placement between matches made navigation software harder).

Re: Drive Systems... ...The FIRST Arms Race?
 

Like the original poster said, a reason for this escalation is because of FIRST game designs.

I think this is in fact the main reason.

Take this year's game, for example. Rack'n'Rolls main scoring device is ONE device, in the middle of the field. Most of the gameplay SHOULD happen nearby it, therefor not that much movement and a robot that can keep where he wants to be is paramount. Sadly, i think FIRST made a slight error in point values with the bonus, which makes creating a robot that in no way plays a scoring game until the end an actually viable(and very sadly, winning) solution. So, what would the builders of this robot do with the rest of the time? DEFEND!!! against those teams that make a robot which actually plays during the match. and since those teams made a robot that is not 100% geared and weighted for defense, they most likely wont be able to out-class the defense machine.

the point I'm trying to reach is....If robots with pushing power were not useful, ppl wouldn't make them, would they?

Just my 2 cents.

Re: Drive Systems... ...The FIRST Arms Race?
 

I think Manual Labor is on to something here. Drive systems have had a chance to be perfected over the past few years due to a relatively similar playing surface each year.

I agree with everyone here who says no more restrictions

What I do agree with is making these perfected drive systems at least partially obsolete.

6wd has seen an incredible jump in popularity over the past few years. Why not make a game in which 6wd and other common systems work, but which aren't the best style for the game.

We've seen many many different types of manipulators over the years because of the different game pieces. Why not translate that to the field and drivetrains? Force teams to innovate to get a competitive edge

Re: Drive Systems... ...The FIRST Arms Race?
 

Some of us rely on "off the shelf" parts. We are a team that has a hack saw, drill press, ruler and a lot of ideas. We do not have the equipment needed to make individual parts. Our high school doesn't even have a metal shop. It would be impossible for us to make a transmission, for example, so we either use the one in the kit or purchase one from a manufacturer. Last year we used 4 motors because we designed primarily for defence. (It was our rookie year and felt that trying to design for using the camera may have been above our abilities.) This year we elected, once again, to go with 4 motors, not for defence but rather to have the ability to climb ramps if it is necessary. Sure, we would love to manufacture our own equipment, but it ain't gonna happen.

Re: Drive Systems... ...The FIRST Arms Race?
 

I don't think a consensus has been reached on this issue yet, but there has been some disagreement this year as to whether the new battery has a short current of 90A or 720A. This document says 90A, whereas this one says 720A. All we know for sure is that it's either a lot more or a lot less than last year. ;)