How can we drive on this new floor?
 

We cant use OMNI's or traction wheels, only the KOP wheels. any ideas of how to drive?

Re: How can we drive on this new floor?
 

The same way you would as if you were driving on snow or ice. It is possible and start off slow to get going.


I think the teams in the snow belt areas will have an advantage with the 2009game :D

Re: How can we drive on this new floor?
 

My guess would be to accelerate slowly to prevent burnouts, and distribute your weight on your back wheels.

Re: How can we drive on this new floor?
 

Well, it's obvious that every wheel touching the ground will need to be powered (otherwise you're foolishly wasting precious traction) but beyond that I don't have many ideas. Would any non-tank drive style drive systems help? Also, am I wrong in assuming that traction force is just a function of coefficient of friction (cannot be changed) and mass (going to be 120 for everybody)? Does increasing the surface area have any affect?

Re: How can we drive on this new floor?
 

There are even a few more factors than that in optimizing traction.
However, to put it simply:
Friction is a function of normal force (weight).
Traction is a function of normal force AND surface area.

Re: How can we drive on this new floor?
 

Would there be any advantage in using crab drive or another drive system like that? Or would a car like drive system be better for towing the trailer around?

Re: How can we drive on this new floor?
 

<R06> says it all. You may use only the KOP wheels.

Re: How can we drive on this new floor?
 

they dident say that we couldent angle the wheels............

Re: How can we drive on this new floor?
 

A holonomic drivebase would still be possible even with just the KOP wheels. The coefficient of friction is low enough that a swerve base or kiwi drive would both be possible, since the wheels slide easily enough.

Re: How can we drive on this new floor?
 

thats exactly what i was thinking

Re: How can we drive on this new floor?
 

I think it may be good to have weight on the driving wheels so that there is plenty of traction for turning and changing direction.

Re: How can we drive on this new floor?
 

There is another rule stating that the wheel's rotation MUST BE inline with movement of the bot, so that the axle the wheel is on is perpendicular to the bot and wheels movement

Re: How can we drive on this new floor?
 

For tank drive systems, what do you guys think about 4 vs 6 coplanar, evenly spaced wheels? Would there really be any difference?

Has anyone felt the new playing surface? How much does it cost? Would plane old hallway concrete be a suitable substitute?

Re: How can we drive on this new floor?
 

could you find this and link to it?

Re: How can we drive on this new floor?
 

I have to agree.

To teams that have no experience driving in snowy/icy conditions- trying to start out going fast (even middle-range speeds) can result in either your tires just sitting there spinning, followed by a jerk forward, or the car/bot sliding out of control.

Re: How can we drive on this new floor?
 

The fewer wheels you have will actually increase you traction because you will have more weight on the drive wheels we are thinking about having a front wheel drive with one more wheel in the back. We would use a tank drive to be able to turn with the trailer.

Re: How can we drive on this new floor?
 

Seems to me it says nothing about requiring the wheels be oriented so MOTION is in the direction of the tread, only that they be mounted with tread touching the floor (i imagine to foil us lateral thinkers that might try to cantilever the wheels and use the flat face of them to try to move forward)

Re: How can we drive on this new floor?
 

im not sure how many of you out there live in the lovely area that gets a lot of snow. but im in new carlisle indiana. and we just get dumped on constanlty. one thing i've notices is front wheel drive cars tend to do better. you can power out of the slide (if you are able to do a car-like steering). and i have noticed that rear wheel drive causes a lot of fishtailing.(maybe not with the trailer). but the best by far is four-wheel drive. it gives you power to all four wheels. team 2197 is without a doubt going with four wheel drive. good luck to everyone. i hope you all have fun with lunacy

Re: How can we drive on this new floor?
 

If you are talking about R06 I don't read it that way. The tread must be in contact with the ground and the wheel axis must be parallel to the ground and through the wheel hub. However, this does not imply "inline. At first read, I do not see what rule would prohibit a crab steering configuration unless I missed something.

Re: How can we drive on this new floor?
 

One thing to watch for when designing the robot is turning ability when using skid steering (tank drive).

If you notice the coefficients of friction for the wheels, you will see that inline dynamic is .05 while transverse dynamic is .10. In a skidding situation the wheel will be twice as resistant to going sideways as it is to going forwards....

That means, as I read it, that your wheel is not going to want to slide sideways very easily if you use 4wd tank drive.

In fact anyone planning on going with skid steering will probably want to really look at using at least six wheels to minimize the amount of skidding required in a turn.

Jason

Re: How can we drive on this new floor?
 

I think the intention of R06 is to prevent teams from using the non-treaded portion of the wheel as a traction surface, not rule out Holonomic or Kiwi type drive systems.

Re: How can we drive on this new floor?
 

2j

Re: How can we drive on this new floor?
 

As I think more and more about this game I've come to a conclusion.

No matter what you do, you'll still be working with limited traction. Instead of worry about getting more traction, why not just embrace the lose of traction?

I think the question of "how can we drive on this new floor?" should be posed to the drivers. It'll require quite a bit of finesse and skill to master the lack of traction but those who do will be at a huge advantage.

Perhaps you should have your drivers research things like Drifting, ice driving, and driving in the rain to get some ideas. I personally, dabble in a bit of drifting myself so I'd like to see if I can apply that experience to driving a robot on this surface.

Re: How can we drive on this new floor?
 

I think the solution for driving on this new floor will be more likely on Software : http://en.wikipedia.org/wiki/Traction_control_system.

Gotta think how does the algorithm work on a 4W drive vehicle works......

Cheers,
Marcos.

Re: How can we drive on this new floor?
 

i totally agree with that. theres no way to increase traction. and i also do some drifting myself. main thing is you cant give a lot of power right away. otherwise you will just spin your tires(wheels). it will require some skills by the drivers

Re: How can we drive on this new floor?
 

It may be even worse than it first appears. Unless you've already broken traction, skid steering has to overcome what could be as high as the static transverse friction (if you want to turn as you are starting out). At first glance it appears 6 wheel drive raised center is the way to go for skid steering (whether tank mode or joystick mode on the controls). Also the abnormally high differences between static and dynamic coefficients is probably worth a bit more analysis. In past years static vs. dynamic and inline versus transverse were relatively minor differences that could often be more or less ignored. Not so this year. Don't count on being able to control the bot until you do the math ;)

Re: How can we drive on this new floor?
 

Darn, the first thing I thought was that we should make a walker bot using the wheels sideways. :D

Re: How can we drive on this new floor?
 

You can add more traction to the wheels by adding downward force onto the wheels. Any additional weight would be dispersed by the wheels regardless of where it's centered unless the robot has another point of contact with the ground (or if it goes all the way through the trailer). So you could add force with springs or with pneumatics, thereby adding traction.

But I'm wondering, could you propel yourself by say, pushing off of walls? There have got to be some ways to move outside of the traditional wheels on the ground that are still legal within the competition constraints.

Re: How can we drive on this new floor?
 

You are absolutely right. Drivers will need to train themselves and adapt to the slick situation. Additionally, I believe that programming will also have a big part in this years game (i.e. Traction Control). Our team will be doing a lot of testing in terms of the best method of acceleration for our robot, inputting that into our system and applying that to our controls.

Re: How can we drive on this new floor?
 

It seems to me that heavier Bots will do a lot better, and I'm sure everyone will be maxed out on weight, so the question is how do you add weight....without adding weight....;) *Hint hint Nudge nudge*

Re: How can we drive on this new floor?
 

That's an easy assumption to make.

But what about momentum? Changing directions with a heavier bot it's going be be a bit harder I think... Or maybe not, I'd like to get some input on this.

Re: How can we drive on this new floor?
 

Sorry to break it too you all but tank drive is going to be a pain, Tank drive has an axis of rotation around the center of the robot. BUT you have a trailer, you are going to be dragging the trailer wheels side ways it will be a battle.

Also the trailer anytime that you backup you will jack knife almost immediately, then you will be unable to control your backwards motion, turning with the trailer.

Re: How can we drive on this new floor?
 

Haha! i bet everyone in the north U.S. has a bit of an advantage with this above average snowfall. similar to snow and ice, you would want to start slow, and don't lock up your wheels... try pulsing them like in an anti lock break system, or just slowing down. weight to increase traction is also double sided, sure you can accelerate faster, but then again you take further to stop weather that be sliding or slowing down. It pays to drive in Idaho!

Re: How can we drive on this new floor?
 

Anyone thinking about workarounds to the traction problem?

If the total traction is a function of your friction, surface area, and weight, and friction is fixed- shouldn't we be looking at surface area and weight?

Surface area is easy- more wheels (I don't think there's a limit)

But weight? could be interesting. Any ideas?

Re: How can we drive on this new floor?
 

In theory though, you should be able to drag the trailer around because the wheels are the same non-grippy wheels that are on the robot. I'd also venture to guess that a trailer weighs substantially less than a robot, but then again I'm not entirely sure...

Re: How can we drive on this new floor?
 

oh man. people are posting fast i guess my last one was outdated...

since people are already thinking about pluses and minuses of weight anyone consider varying the "weight" of your robot?

Re: How can we drive on this new floor?
 

To add wieght with without adding wieght you could always fill up your trailer

Re: How can we drive on this new floor?
 

In theory, one could construct giant omniwheels using each Rover Wheel as one of the horizontal rollers...

Re: How can we drive on this new floor?
 

Yeah by adding to the trailer you gain mass - just not on your drive wheels. You'll gain momentum, just not traction. Plus you're giving the other team points.

Re: How can we drive on this new floor?
 

Traction is detirmined by pounds per square inch, so more wheels is taking away from your traction on each one, so every non-drive wheel is a waste of potential traction theoretically.

All wheels have the same coefficient of friction so because of the wieght differential the trailer will move, but slowly

Re: How can we drive on this new floor?
 

I am a driver from the FRC team 1741. I like the idea of drifting to gain more control of the robots. My only concern is that with the trailer it will be very hard to turn quickly. Can you get enough speed to drift in the arena?
:ahh:

Re: How can we drive on this new floor?
 

While a great idea...

I think the emphasized part of R06 might disallow that, along with the general logistics of building giant omniwheels. :D

Re: How can we drive on this new floor?
 

In response to adding weight without adding weight, you could add fans to the bottom of the robot to draw in air from the bottom, just like those cars that can climb walls. Don't know how much it would increase the normal force though.

Re: How can we drive on this new floor?
 

There seems to be a lot of confusion going on about some physics, I think this should help:
ForceFriction = Mass*Gravity*CoefficientOfFriction
surface area is not a part of the calculation, as increased surface area means the normal force (force of the ground pushing up) is more spread out.
Force = Mass*Acceleration
thus
Mass*Gravity*CoefficientOfFriction = Mass*Acceleration
mass cancels
Gravity*CoefficientOfFriction = Acceleration
which shows that maximum acceleration is a function of nothing more than Gravity and the Coefficient of Friction, neither of which can be changed. Any team that powers all wheels in contact with the ground will have a top acceleration of .588 assuming no slippage (.06 cof) or .49 with slipping (.05 cof). The top speed assuming you drive straight across the regolith is approximately 2.2 meters per second, or about 5 miles per hour. The trip would take about 4.5 seconds.
By the way, where is everybody getting the coefficients of friction? How accurate are they? Doe anybody know the cof of the wheels on carpet?

Re: How can we drive on this new floor?
 

What if your robot had two drive trains? One in the forward direction and one in perpendicular to the forward direction. You lifted one drive train to use the other. Kinda like the trucks that are made to drive on the road and railroad tracks.

Re: How can we drive on this new floor?
 

Well what if you could control how much you wanted, you know actively change from a heavier bot to a lighter bot in the middle of a match, you could start moving by being light, "make" yourself heavy if you don't want to be pushed etc.

I do have an idea for this, but I'm trying to stimulate the thinktank, see what else people come up with :)

Re: How can we drive on this new floor?
 

car steering might make a comeback this year......seeing as how tank drive wouldent turnas well,(drifting around with the trailer would take some getting use to though)

Re: How can we drive on this new floor?
 

I believe R06 would only apply to the wheels being "used" - that is, the ones touching the ground. The configuration would then be legal, since the wheels not satisfying R06 would not be in use.

Such an omniwheel would have nearly triple the traction of a single Rover Wheel.

Re: How can we drive on this new floor?
 

Reading R06... It says to me that no devices at all (making contact or not) may be used as a "traction device". The intent is that all robots have similiar traction on the surface. Increasing your force via suction would be a "traction device" in my mind

Re: How can we drive on this new floor?
 

Some quick suggestions off the top of my head:

Giant Flywheel. For resistance to bumps and bruises, spin up a giant flywheel to help you conserve momentum.

Traction Control. This was mentioned before, but I'll summarize the idea of a traction control system. In a car, you compare the speed of the powered wheels to the unpowered wheels. If there is a difference, that means one set is slipping while the other isn't. The computer cuts a bit of power to the driven wheels until both spin at the same rate. For a 4-wheel vehicle, you can use an accelerometer to get the differential measurement.

Mariocart for Driver Training. Mariocart invented drifting. Blue sparks may be a safety hazard, though.

Pneumatics as Thrusters. Satellites use gas thrusters to control direction. If the surface is low enough friction, this could act as a nice stability augmentation.

Antilock Brakes. Antilock brakes don't necessary cut down on braking distance, but rather they give you control WHILE braking. If you slam on a car that doesn't have antilock brakes and you lock the wheels, the car basically keeps moving in the direction of its momentum vector, regardless of which direction the steering wheel is pointing (conservation of momentum). With antilock brakes, you're switching between static friction and dynamic friction, and in a nut shell, this gives you some control (ie allows you to swerve around the object you're braking for).

Physics 101. Actually, Physics 8.01. For the truly adventurous, check out Walter Lewin's physics videos on MIT's OCW, specifically the lecture dealing with friction. http://ocw.mit.edu/OcwWeb/Physics/8-...il/embed08.htm. This is roughly equivalent to an AP Physics class.

Re: How can we drive on this new floor?
 

zyck I think you and I are on the same train of thought. Still wondering about how to implement it though. Lets see if anyone else comes up with it.

Btw. Has anyone thought of just hanging out in the carpet and speeding around everyone? you'd have to be a great shot with those balls but it would be tough to score on you

Re: How can we drive on this new floor?
 

ive seen bakes before....would be tricky to get anti-lock brakes,although i dont think they would help that much, maybe if you had traction control and anti-lock brakes?

Re: How can we drive on this new floor?
 

All this talk about effectively driving in these low-friction conditions. I would instead think of how the other parts in your kit can help you score DESPITE the poor driving controllability conditions.
Two things off the bat I saw in the kit and my concrete memory of team 25 in 2006. The lazy susan turet (or equivalent) and the camera. ;)

Re: How can we drive on this new floor?
 

Yes, we thought about staying on the carpet but we decided it would be a bad idea because like he said, you would be an easy target and you will only be able to have at most 1/2 of your robot on the carpet.


P.S. How do you guy get thebluealliance name thing on there?

Re: How can we drive on this new floor?
 

Mray

We thought of this, but our team decided not to do it Because;
A.) too much fabrication (time money etc)
B.) too much tuning to get it right (time)

But basically Thrust downward, with it you could dynamically control weight throughout the match, getting advantages of heavier btos and lighter bots, whenever you needed it.

Re: How can we drive on this new floor?
 

I dont think they will allow anti-lock brakes. They said at the kick-off that the only thing that can control the speed of the tires are the new jaguars and the old things. (I forgot what they are called.)

Re: How can we drive on this new floor?
 

Very carefully

Re: How can we drive on this new floor?
 

I still need help on thebluealliance thing please.

Re: How can we drive on this new floor?
 

You can pulse "brakes" electronically. Plus you can control the coast/brake setting on the jaguars with the Digital outputs

Re: How can we drive on this new floor?
 

The "old things" are Victor 884 speed controllers from IFI.

Antilock brakes and traction control are implemented using software and sensors. The Victors or Jaguars are still used to control the motors.

Re: How can we drive on this new floor?
 

try here
http://www.thebluealliance.net/tbatv.../teambadge.php

Re: How can we drive on this new floor?
 

So here's my basic Idea for anyone who was following, Use a fan or such to provide thrust downward, or basically a (much) lower pressure area underneath the bot, the result (hopefully) would be more weight force downwards, making up for that lost weight force from the low traction, I'm not entirely sure exactly how to implement, and I'm not bothering to run the math on how much airflow is required to make up even say 200 lbs, but something like this might be sufficient,

any thoughts?

Re: How can we drive on this new floor?
 

the rules specify that the Rover Wheels are the only thing allowed to provide "traction"

Re: How can we drive on this new floor?
 

after you do the colors, you have to get the "code" and put it in your signature....

Re: How can we drive on this new floor?
 

This is something that Buzz (FRC175) has done to great success in the past. Look up some old video - it's pretty spectacular.

Re: How can we drive on this new floor?
 

Isn't using a fan to create a low pressure zone not considered a traction device? I doesn't directly contact the ground nor does it actually constitute any solid form of traction as it would rely on a limited power supply. Such a device could not be used continuously throughout the match (just an estimate, no supporting math) as it would deplete the battery and rob power to the wheels. This is, of course, dependent on your drive configuration (four wheel/two wheel drive) and other systems such as pneumatics. This would, however, be very useful for acceleration and cornering if it could be designed with minimal spin-up time.
On a separate note, is there a rule stating that we cannot use any sort if thrust based propulsion system and just mounting the wheels as unpowered casters? Such a device wouldn't even rely on traction at all...

Re: How can we drive on this new floor?
 

How effective would it be to use an accelerometer and a rotation sensor to not allow the wheels to go far beyond wheel slippage. You could maximize the traction with out spinning all over the place.

Re: How can we drive on this new floor?
 

Is that low pressure zone intended to increase your traction/performance on the playing surface? If it does, then I would believe it would be defined as a form of traction enhancement. Contact does not matter.

Re: How can we drive on this new floor?
 

"fans" = shades of CanAm Chapparel 2Js. They only raced the one year way back... kinda funny to see shredded debris ejected by the two 45hp ducted fans though. Quickly banned as not fitting the FIA racing rules.

Re: How can we drive on this new floor?
 

Think. If this were true, then weight could be "a form of traction enhancement", similar to any traction control ect. Meaning anything on the robot is outlawed, as it adds weight to increase traction.

Re: How can we drive on this new floor?
 

haha its like a car on ice...=D

Re: How can we drive on this new floor?
 

Obviously you don't drive the robot.

Re: How can we drive on this new floor?
 

Hate to break it to you, but a lot of teams have some innovative programming planned. *hint hint* *wink wink*

There are always ways to work around obstacles...even if they're on the moon.

Re: How can we drive on this new floor?
 

Guys no back to back conversations in threads please. Either stay on topic or use something like AIM or the PM function.

Re: How can we drive on this new floor?
 

^ No double posting, theres an edit button for that :P

Re: How can we drive on this new floor?
 

I have one, the fan in the link draws 8a of current and the hardware we have can only take 3/4a. Also I am thinking that there is little way of creating enough force to hold the robot to the Crater. One of my team mates did the math and estimated that you will need to move over 900 cubic feet of air per minute :). It might very well be possible to use a fan to create more downforce, I know it has been done in racing, but the question is going to be one of how much weight can you spare to add it in, how much room do you have for it, and more importantly can you spare that mush energy from your system to power it and all the other essential items.

Re: How can we drive on this new floor?
 

The post was meant to point out to specific people. ;)

Nevertheless, touche.

Re: How can we drive on this new floor?
 

Eh, figure it's time to stick my nose in here.

Anyway, Titan's idea about augmenting the robot's downward force is an interesting one. Keep working on that, you really could have something there.

Folks, FIRST just took the box we've all been thinking in and ripped it to pieces. Even a kit chassis is stuck in the high traction environment we've had. It's time to shed all these ideas of how we used to move, and really DESIGN around CONSTRAINTS, much the way the real world works. What you're all seeing and experiencing is a valuable skill, so don't blow this one off.

That being said, I have absolutely NO idea what to advise my team to do... I've spent all of today doing different designs, all of which end halfway when I realize different factors.

Re: How can we drive on this new floor?
 

We bought two 4' x 8' sheets of that "ice" material ($30 per sheet) for the floor and did some testing. We compared traction on the "ice" the carpet and plain old tiled floor. The ice was the slickest. The carpet was slick but not as bad. The tile was surprisingly almost the same as the ice. So, to answer your question, if you cannot afford to buy some of the ice material, use a tiled floor as your best simulation.

Re: How can we drive on this new floor?
 

Many teams used 4 CIMS for their drivetrain in past competitions. It seems that 2 CIMS would be sufficient to drive the wheels this year. How much more traction would you get from 2 CIMS driving fans? what if the fans were used for purplusion instead? i.e. like an airboat.

Re: How can we drive on this new floor?
 

Did you collect and numbers to help us compare?
I was thinking that we might stretch a large sheet of plastic over a tile floor and tape down the edges. If the plastic is thick enough, hopefully the robot will not wrinkle and tear it long enough to practice.

Re: How can we drive on this new floor?
 

hahaha, I do love these propulsion ideas.

But i think that teams are making this much tougher for themselves by not looking at what by some people has been described and explained to me as simple physics. Why make it harder on yourself by making that hypothetical propulsion robot? Think of the new challenges you create for yourself. A part of engineering, as what I've been taught by my grandfather, is not only creating solutions, but moving closer to the obstacles at hand, and not creating new ones for yourself.

Sure propulsion would be innovative in an FRC robot, sure it'd be tons of fun, but look at the new challenges you're bringing up for your own team. How would this effect the physics of you carrying the trailer? When you turn, the inertia of that trailer will lead you into a corner with propulsion. A hybrid of propulsion and wheels is almost useless even if it is deemed allowed (which by the "no other traction on the field allowed" part of the rules can't be done anyway).

Ranting aside, my point is just for teams to think more clearly in their ideas. I'm not an engineer so I'm not saying you even have to listen to me or consider my advice, just don't create new obstacles for yourselves.

Yup Sean, it looks possible. I've gone over the CoF with a lot of people and depending on the orientation of your wheels, you could in theory do a Kiwi type holonomic drive. I'd rather test it out though.

Re: How can we drive on this new floor?
 

So does anyone want to chime in about using these wheels as omniwheels. Would it even be possible. I am feeling slightly lost since all of my preseason designs involved mega-traction and multi-speed high torque transmissions

Re: How can we drive on this new floor?
 

So Zyck_titan it seems you had the same idea I did... >.< and I thought I was original.

We did the math and with a 480 watt (the maximum wattage motor allowable) you could produce just under .2 psi. (allow variance for rotor blade type) Numbers for this were taken from a website publishing the Static Pressure capabilities of their 480 watt fans. (we then did conversions to psi)

Now you have to multiply by the square inches (maximum allowable 1064 = 28x38) and we get about 213 pounds of extra force.

So if you had a skirt around the entirety of your robot you could conservativly expect to roughly double the weight/normal force of your robot. (you'd lose a lot due to inefficiencies)

This means that when applied to F=MA in regards to your acceleration you can expect to take it from roughly .6 m/s (static friction with no fans) to 1.2-1.5 m/s (static friction with fans)

Now logistics might be a tad tough but hey if it gives you double your friction then it's worth it in my book. The real problem... ripping up the play area. If it isn't secured you would just vacuum it up and be completely stuck. This seems a real problem to me since when you look here ( http://thebluealliance.tumblr.com/po...field-elements ) at the end you can see the edge of the field which is merely secured with TAPE and now if this is a thin linoleum style roll you would just suck it right up and then... you wouldn't be able to move and might even get a penalty for destroying the field.

...after further research ( http://www.frpshop.com/pdf/installat...structions.pdf ) assuming FIRST followed these rules for the construction of a gasolenar frp floor it might not be too much of a problem...

Re: How can we drive on this new floor?
 

Omniwheels are specifically designed to have a lower coefficient of friction in the transverse direction than in the inline direction.

These wheels, according to the manual, have a transverse coefficient of friction that is about twice that of the inline direction. They are, by my reading... anti-omni wheels.

Jason

Re: How can we drive on this new floor?
 

I agree

Re: How can we drive on this new floor?
 

The coefficient of transverse static (or kinetic for that matter) friction is significantly higher than the Inline coefficients of friction. I can't help but imagine that some use could be had from the transverse friction.
The the higher friction could be used to create a centripetal force to assist in turning, which would require that the wheels rotate.
Or, a foot could be made from a perpendicularly positioned wheel, and use the transverse coefficient of friction to help stop the robot. Would that be legal?

Re: How can we drive on this new floor?
 

It doesn't make sense to me why one would be higher than the other the wheels are molded and don't have any sort of "stepping" that would cause this ... any idea as to why one would be greater than the other?

Re: How can we drive on this new floor?
 

Did you do any testing on terrazzo floors? (The stuff where a slurry is poured, and then polished after it hardens)

Re: How can we drive on this new floor?
 

Alot of people's response to this problem reminds me of an exercise we had to do at a workshop that work had us do to advocate thinking outside of the box. They had us put up our hand and the guy would push it. Of course out of reflex we would resist. And he asked us why we resisted? Because it our habit to do so. Sometimes instead of just resiting the forces that are working against you is to loosen your control and work with those forces and allow them to do the steering.
Seems to me what people have the biggest problem here with is being in complete control of their robot and are trying to come up with every possible solution to regain that control when maybe the best solution is to embrace the lack of control and use it to the advantage like the guys who suggest the drifting training. You could waste alot of time and energy otherwise.

Re: How can we drive on this new floor?
 

Some of my team members and I calculated that using 2 sim's and suction cup properly you caould add an extra 600 pounds to your robot with ever touching the ground... Any Ideas?

Re: How can we drive on this new floor?
 

Shade of 2003.
Teams used suction cups to plant themselves at the top of the ramp. That worked for the first few matches and then after getting ran over by robots for a while the field surface got worn down a bit and the suction cups stopped working.
I suspect the same would happen this year as well.

Re: How can we drive on this new floor?
 

Yes, weight does help traction, but it is a legal addition to the robot to a limit. Increasing your traction beyond your idle state/curb weight I think would cause the issue.

Traction control is legal because it is increasing control electronically. Not changing the physical interaction between the playing surface and the rover wheels

Re: How can we drive on this new floor?
 

I see your point, but that math was done assuming that the suction cups are about 1/2 to 1/4 of an inch off the ground. They would be more like a hover craft in reverse then suction cups.

Re: How can we drive on this new floor?
 

I don't think it is useless. The maximum force that can be generated with the wheels for a max-weight robot is 26.7N. With some math, you can determine that 5N and 10N fans could be plausibly added to your robot, which would add 18% and 36% to the acceleration of a max-weight robot, respectively. Some of that would be eaten by the airstream hitting the trailer, but I think a fan approach could actually increase performance.

I think there is a reading of the rules where it would be allowed. Traction generally refers to the contact between a wheel and the ground. Fans aren't enhancing your traction with the field (and unless you have a quickly reversible fan, they actually hurt your braking performance), they are applying a force by pushing against the atmosphere. However, there are also readings of the rules where it wouldn't be allowed, and it'll have to wait until QA opens to see if they are allowable.

Re: How can we drive on this new floor?
 

Last year we were one of a few teams that used a vacume to pick up the ball so we have some experience with them. One of my friends on the team picked up the ball just using his mouth. He sucked on a vacume tube atached to a cake holder lid. With that much of a surface area he could pick up the ball for about 5 seconds.

Re: How can we drive on this new floor?
 

Does this make any sense? Six wheeled bot. Four corner wheels driving forward and two side centered wheels driving backward as needed. Or, one wheel dead center of bot that would spin oppisite as needed. Then hand the whole thing over to programers. They can make it work.

Re: How can we drive on this new floor?
 

Look, all the ideas with fans:

Why not take your 200 pounds of force going downwards, point that to a side, and use it as a means of propulsion? It would certainly be a lot more efficient than using the force to increase the traction (it will still be low traction).

-Vivek

Re: How can we drive on this new floor?
 

Would a holonomic drive system work well? I think it would make it easier to drive, but I don't know for sure. Here is a link to a picture of what I am talking about except that we would have to use the required wheels instead of the omnis. The required wheels should work as well though, because they barely have any traction.
http://wiki.chiefdelphi.com/media/0/..._holonomic.jpg

Re: How can we drive on this new floor?
 

You would have to use the wheels in the kit as the casters, the wheel would be huge and bulky but it could work. Now you have to know that an omni-drive works on the principle of wheel slippage. It is designed so that wheel casters slip.