Drive Train & Control Types '07
 

I'm at the Peachtree Regional in Atlantaand i have seen a lot of omni drive trains. Many are the set-up of 2 omni, one on back and one on front....
What is common at the other regionals?

Also i have seen some very innovative control schemes!
Team 1261 won an award mainly for their mix of a Guitar Hero guitar controller and a Xbox 360 controller!
Are there any more kinds out there?

Re: Drive Train & Control Types '07
 

can you get a picture of 1261's control board?

Re: Drive Train & Control Types '07
 

Up at Chesapeake, it seems that we're seeing a lot of kit drivetrains (loosely defined as BaneBots transmissions and AM kit wheels, most with the kit frame). There are a few IFI wheels, but there's about as many teams running AndyMark mecanums to varying degrees of success.

However, mecanums haven't completely killed off traditional omni--both 341 and 1418 are rolling on some variation of AM omnis (plastic for 341, aluminum for 1418).

Re: Drive Train & Control Types '07
 

Personally i find 175 drivetrain to be wonderful. It isnt new but every year it helps them do wonderful. They use 2 drivetrains. One is the normal bot 6 wheel 4cim drivetrain and then they have another drivetrain mounted sideways underneath the chassis on pneumatic pistons. When this drive train pops down it enables them to physically move sideways.

Powerhouse drivetrains are also do verywell this year because defense and pushing robots aside to score ringers is big.

Re: Drive Train & Control Types '07
 

Not really much of a control board, just 80-20 and plexiglass. For the Guitar Hero controller, instead of trying to interface with the Playstation2 plug, we just ran wires directly from the switches to the pinouts. We then used a USB Chicklet for the XBox 360 controller.

Our drive system (all wheel drive) was chain-driven off of two large CIMS with two IFI "sticky" wheels in the front and two omni wheels in the back, and operated with the Xbox controller. Our manipulator (sorry, no picture) was a cable-operated elevator that had two "fingers" that would slide under a tube, and two rubber wheels that would pull a tube in and rotate it upward to about a 30-degree angle.

The winch was a small CIM with a BaneBots gearhead and encoder....so we used 3 of "string" buttons on the guitar for high/medium/low positions, with the other 2 buttons used for manual adjustment. The load/unload function of our grabber was then controlled by the "strum" switches on the guitar.

Re: Drive Train & Control Types '07
 

This seems to be the year of the crab. I have seen so many great teams use it including 71, 111, 118, 384/1086/540, 469, 1503/1680 648 and 1625. It has been very interesting to see all of these teams sliding around the field. These drivetrains are very good but they require some very skilled drivers to operate.

I also was impressed by 703's 14WD. No that is not a misprint. Search CD Media for it. The strength it gave them made them strong defenders and they are able to get up just about any ramp that is put down in front of them.

The two quickest drives I have seen are 247 and 1114. I know the Simbots can get to 14 FPS and I would not be surprised if Da Bears weren't going at least that fast. These two robots are going to be scary at championship.

Re: Drive Train & Control Types '07
 

Here in California, I have been seeing mostly 4/6 WDs, lots of interesting omni setups, and a few mecanum drives (my team is the only one I've seen so far with non-AM mecanums).

There was one very interesting omnidrive at SVR (I think it was team 362) that used two wheels on each side of the bot, with each pair parallel to its corresponding side. Pretty wicked looking :)

I also saw one with AM omnis arranged at 45 degree angles, much like mecanums.

I really like 254's 6WD drive. It's not only faster than my team's mecanum bot (which can go about 13-14 fps), but it can turn on point better than us :eek: Even though it has a significant lack of pushing power, the agility is beautiful.

Re: Drive Train & Control Types '07
 

422 also did the first method of omni wheels, although for ramping I think that the 45 degree method would have been better.

We also controlled it like a first person shooter game to try and get a more intuitive drive system.

Re: Drive Train & Control Types '07
 

Lack of pushing power? I think they would be upset if they heard that...

They have a 5fps/16fps (or 6/15 I forget...). The high gear is very fast, and the low gear is putting out a significant amount of torque, probably just around traction limited knowing them (which is a lot, using gum rubber roughtop tread... which is about the highest coefficient of friction you can legally get for wheels). So, I'd say they can push if they need to; They're just too busy scoring.

Re: Drive Train & Control Types '07
 

I don't think they are using bumpers, and I think they are in the 110 lb weight class. So, they are at about 124lbs, with battery (maximum). I also read something about them weighing about 85lbs, because they were planning on adding ramps. If they didn't add weight to get to 110lbs, then they are really scrawny at 100lbs, with battery. That hurts their pushing power. 100*1.3 is equivalent to 150*.867, about the amount of traction advantage a full-weighted 4ft class robot would have with something even less grippy than the old wheelchair wheels that were in the kit. They have the torque, and they have the treads, but they are lacking the weight.

Re: Drive Train & Control Types '07
 

As did we with our Xbox controller - left thumbstick was throttle, and right thumbstick was steering.....so basically the same as Halo :)

Re: Drive Train & Control Types '07
 

384, 1086, and 540 (the West Henrico Triad) actually used Mecanum, not crab.
With a few exceptions (111 @ MWR, 540 @ VCU, 175 @ BAE, and probably a couple others), the traditional "tank steering" drive has won every event. Although, this may be (at least in part) a bi-product of the vastly higher quantity of these drives.

Re: Drive Train & Control Types '07
 

Im a little confused about the post about omnis at Peachtree. Yes teams used omnis but not in an actual omni drive they were only used as casters more or less to allow for easier turning.

Re: Drive Train & Control Types '07
 

Yeah, all of the omni wheels I saw were just used to aid turning, like we used. There was one crab drive (1057), and one robot had mecanum wheels (I forget the number) with independent suspension. :cool: Other than that, though, I think all other robots were 4- or 6-wheel tank drives.

Re: Drive Train & Control Types '07
 

We used the 2 omni 2 traction wheel method like other teams. With 2 motors to a transmition (having 2 transmitions, so a motor per wheel essentially) we had plenty of pushing power and speed which made it easy for us to defend or score. Even though it gave us the power and speed we needed, it wasn't enough aginst an all traction drive system (that wasn't pretty....)

Brian Richards, 1983 Mechanic

Re: Drive Train & Control Types '07
 

Becuase now with all the power being put into drivetrains you need a solid way of connecting with the floor... high traction wheels and power will get you far in any years game.

Re: Drive Train & Control Types '07
 

I must say we are very happy with our 6 wheel drive system using 2" wide colsons and andymark 2 speed transmissions. We haven't been out-pushed yet after 2 regionals. :cool: and we haven't had a single problem with it yet.

Re: Drive Train & Control Types '07
 

Do the old wheelchair wheels realyl have that much traction? The new AM wheels are 1.0-1.1 and they seem to have a lot more traction than the skyways...

And to contribute to the post; At LA we ran two small CIMs on each side to 1.2 cof wheels in a 6 wheel drive. We weren't traction limited and had a 9-10 fps top speed. For San Diego, we are probably switching to a small CIM, a large and a FP (modularity and CNCs = awesome) which will give us the same speed, but we will be traction limited so we we'll be able to push a lot better.

Re: Drive Train & Control Types '07
 

Buzz's lateral drive is actually new this year. We have used the 6 wheel drive before (more than once), but not the lateral.

I hadn't seen any regionals in person this year, and it is very different watching the video feed where you cannot see the whole match. But I was at UTC this weekend, and I certainly came away with the impression that a strong drive train is very important this year. (last year as well, of course) It has certainly been important in other years, but this year there are many many ramp bots who don't score until the end of the match, and they play very strong defense during the rest of the match. I've seen really good and innovative scorers be shut down by great defensive bots. The scorers with stronger drives (and good drivers) are scoring.

Re: Drive Train & Control Types '07
 

I forget the team number as well but I saw the mecanum/suspension set up in their pits and it was impressive looking.

Re: Drive Train & Control Types '07
 

It is 5 in low and 15 to 16 in high. The first statement was true about us not having much pushing power as we weighed in at about 90 pounds at each event since we did not have ramps.

Re: Drive Train & Control Types '07
 

That was ours, team 1379. It works great, you can drive over a 1x4 with it! Perfect for driving over field debris.

I will ask Matt to post some pictures of it when we get the robot back this week.

Re: Drive Train & Control Types '07
 

Our crab drive made getting aligned to ramps alot easier...
a lot of robots had to get running starts to make it up some ramps.

Re: Drive Train & Control Types '07
 

Team 703 took a deviation from our normal tank drive system and came up with a new powerhouse drivetrain....


14 WHEEL TANK DRIVE!!!!! :yikes: :yikes: :yikes:



No joke either,

For more info, see This link, and This other link

:D

Re: Drive Train & Control Types '07
 

At the Silicon Valley Regional, I saw a few teams with omnidrive wheels (two, three teams maybe), only noticed one team with Mecanums, and a lot of 4 or 6-wheel tank drive systems. A few rocker chassis, too. I know teams 100 and 254 were running rocker chassis setups.

675 ran a 4-wheel tank drive setup with one CIM+Gearbox per motor.

We also saw one or two teams with authentic tank tread setups, I know 670 (Homestead Robotics, HRT) ran tank treads.

I forget the number of the team, but I saw a mecanum-bot going sideways at the practice area at San Jose and it was really cool looking -- now I want to build a bot with Mecanums.

Re: Drive Train & Control Types '07
 

We (341) used four AM Plastic Omniwheels this year. At Jersey, they were arranged in a diamond (kiwi style). However, we had bad slippage and controllability issues with this configuration.

For Chesapeake and Philly, we re-oriented the wheels a bit. The front left and rear right wheels go forwards/backwards, and the other two go left/right. This allows for:

1. Stability from all four corners of the robot.
2. Higher straight line speed in the principal axes than either kiwi or mecanum drives of the same gearing.
3. Mechanically straight driving. Try getting a kiwi bot driving straight without slippage or sluggish response, even with encoders and gyros! (We did, we failed, and then we changed it).

The drive is still holonomic, but way easier to control and operate in this configuration.

I also believe that this makes 341 (and I could be wrong about this) the only regional winner with a true holonomic drivetrain.

Re: Drive Train & Control Types '07
 

I suspect you mean 1072, Harker Robotics. Unless 1138 was up there. (The two most likely that I can think of, and I know that 1072 was up there.)

Re: Drive Train & Control Types '07
 

We didn't go up to San Jose, so it was probably 1072. I remember seeing a mecanum bot at LA that didn't use the AM wheels. It caught my eye because they used a record as their rotation control. Was that 1072?

We went with the AM wheels. Got the job done, and we had a decent amount of pushing power and controllability.

Re: Drive Train & Control Types '07
 

We, for the first time ever, used a "Sworm" drive. It is, to the best of our knowledge, the first application of a worm gearbox crossed with a crab drive. It has 180* rotation and our driver has done well with it.

I have noticed this year a few crab drives (1 at St Louis, 2 at GTR). There were a few teams using traditional omni-wheels with a diagonal setup (854) and a good number of teams trying out mecanums.

Re: Drive Train & Control Types '07
 

we've got 2 speed pneumatic AM shifters with custom made direct drive shafts connected to a wheel then the direct wheel has a chain going to another wheel on each side we have a small drive wheelbase in the back with omni wheels in the front for stability
we also had 4 custom 3"wide wheels with an 8" diameter