Is there a Need for Speed???

[oreocookeee]

i realize my post was very one sided. i wanted to support the side that i didn't expect many people to take. im just trying to think outside the (gear) box. im sure there are a ton of exceptions to everything i said, but i stand by my assumptions and generalizations.

i know that controlling the robot usually isnt a problem for the experience programmer and driver, but a rookie or inexperienced team may have trouble controlling a bot with a max speed of 12 ft/sec. this is my team's third year and we are still learning as we go along. our robot last year was meant to lock onto a stack of up to four bins, but partially since the robot had to be precisely lined up, we only managed to pull it off once.

as for crossing the field, some robots will be crossing but i do think that it will be at a smaller frequency than last year. last year, robots started on the opposite side, crossed back to gather bins, then ran across again to knock down stacks (again, this is a generalization, and a bad one at that). this year i would not expect robots to make the circuit across the field and back more than once, if at all.

[PMGRACER]

Teams that have high and low gear will have both torque and speed. Six wheel drive should be sufficeint. A turret will enable you to manuver easily.

[Gope]

Speed is the key this year, without a doubt. Although, one must consider that we are limited not only by hardware and software but also by human reaction time. You need to make sure that you team doesn't over do speed, because as I have witnessed last year, too much speed very quickly becomes a lack of control and thus a nearly useless robot. This year, I feel that gears a needed, not to control torque but to control a maximum speed.





Teams I expect to be blazing fast: 25, 60, 111, 312, 343


I also expect this year to be the year of the driver. I think that this year we will, more than ever, see excellence in driving technique and skill to be as great of a deciding facot as the quality of robot(ofcourse, this is an overstatement, but not a huge one).

[KenWittlief]

to control any bot well you need to do something more than let the joystick inputs control the motor PWM outputs directly

FEEDBACK is probabally THE most powerfull tools at an engineers disposal!

When a drive train is geared up for speed, the stall torque is not very far above the friction in the drive train when you first start to move. that means if you are using two drive wheels to steer, then its almost certain that one will drag a little more than the other, and when you try to make small movements, or to go straight, the bot will not act like you want it too.

that why you REALLY need a yaw rate sensor and/or wheel movement sensors to close the loop - so the SW can tell the difference between what the driver is asking for and what the bot is actaully doing, and make the necessary adjustments and corrections all by itself

closed loop steering and closed loop speed control is a BEAUTIFUL THING!

[Aignam]

Originally Posted by Gope

Teams I expect to be blazing fast: 25...

All I can say is...

!

But yes, I think speed is essential, this year. With so many tasks to be done, and so many levels for these tasks to be done on, even if your robot only intends to perform a few tasks particularly well, you still need a robot that can move across the field and from level to level quickly. A robot that is on the hanging bar before any others is also going to have a one-up on the other teams.

EDIT: After having read the rest of the posts on the thread:

This year is going to be the year of drive team cooperation. You need a quality robot, a quality human player, a quality driver, and a quality coach to keep your quality drive team's head from exploding.

[Dorienne]

Originally Posted by Aignam

This year is going to be the year of drive team cooperation. You need a quality robot, a quality human player, a quality driver, and a quality coach to keep your quality drive team's head from exploding.

Very very true.
Also, hi! I'm from Team 007, and we allianced with you all at Duel on the Delaware. :-D
~Dori

[Levaman]

Speed Holes is a new term for me. I understand it and know that they hold pros/cons.

Pros: Speed
Less Weight
no need to swiss cheese
Cons: Weak Body unless done right
less surface area to push with in some cases

Not a bad idea, but see if you can build the robot with them built in.

[KenWittlief]

Ok... um

'speed holes' is a reference to a Simpsons episode. Homer was wacking his car with a pickaxe (I forget why) and Flanders asked him what in the world he was doing?

and Homer sarcastically replied "Im adding speed holes, dont you know anything about cars Flanders?"

[Jones571]

speed holes? jake u out did your self with that reasoning. i will not let u swiss cheese our bot 14fps is fast enough with out cutting holes in it!

[Lisa Rodriguez]

Jake, you didn't have speed holes last year, neither did we.

Speed will not be top priority, although very important. I believe manuverablility will be MAJOR this year, especially with the field being 6 feet shorter. Speed is always nice, but you can sometimes sacrafice speed for manuverablility, being that you need it. I know my new driver from last year had to practice A LOT in high gear (15fps i believe, if i remember correctly) in order to control the robot, It's a dangerous speed to stay at, especially if your driver does not have a lot of experience. My favorite is the two speed, like the one our team has had. High speed to go from one end to the other, low speed to manuver and have torque. But then again, that could be just me and that's all i've ever known, but hey, i still like it!!

[Andrew]

Speed is only valuable over a relatively long distance. 15 fps only makes sense if you are going to go the full 40 ft. across the field. Hopefully you don't run into an obstruction somewhere in the middle (like the steps or a robot coming the other way).

Acceleration will be much more important this year than speed. How rapidly can you reach top speed and how effectively can you maneuver.

I'm surprised at teams that want to go really, really fast in autonomy. Teams are probably going to go to the center of the field (since that's where most of the scoring objects are). Do you really want to meet a 15 fps robot coming the other way?

15 fps + 15 fps = 30 fps -> lots of robot parts on the field.

[Solace]

we did too have speed holes! i spent 4 hours cutting them!
the reason you guys didn't have them was because you weren't imaginative enough to max out your weight requirements

[KenWittlief]

Do you really want to meet a 15 fps robot coming the other way?

no, i want to get to the release ball first, then get outta the way of the other bot :^)

[Jones571]

even if you try to avoid it there will be lots of robot bashing this year trying to fit through the narrow allies on either side of the platform especialy with the goals takeing up a good portion of the area.

[Andy A.]

Just to clear up the speed hole issue;

When some one talks about speed holes, all they mean 99% of the time are holes drilled in the bot to make the weight limit. They got the term speed holes from a Simpsons episode, and because getting rid of extra(dead) structual wieght can only make you faster. Besides, when some one asks why you're bot looks like a macoroni strainer, its cooler to reply 'Oh, those are the speed holes' then 'Oh, we were 3 pounds overwieght...'

So when you see a bot that looks like swiss cheese, it really means the bot iss really really fast

-Andy A.