Judging by our test of our line tracking on our robot, we'll be doing good to get to the ramp before the end of the match.

Mabye if we used better line tracking I would say 6 secs.

I"ve convinced my team to make a launcher, so we"re planning on knocking over the stack with a flying box about the time other teams are headed up the ramp. From what has happened to humans having stacks fall on them, it seems that whichever alliance gets the stacks knocked onto them will be at a great disadvantage not only because of the boxes they have to move into their scoring zone, but also because of the damage ad obstacles the boxes will present to them.

OMNI DRIVE :)

???

Technically with omni drive you switch directions, you don't turn


Oh, I'm not sure if anyone has worked this out yet, but anyone going over 16ft/s may want to consider building shocks into their robot and you probably don't have to worry about traction on the slick stuff at the top of the ramp, as you won't be touching it.


Greg

Just remember, someone has to program the autonomous code. Unless you are planning on waiting for the 15 seconds to be over, then you will probably be out of luck. ;)

I think our robot could get to the boxes in about 2 to 3 seconds max. Our robot can move about 16.0-17.5 ft/s depending on the surface. I'm most likely underestimating.

if you go 17.5 ft/s over the ramp, I wont be supprised if you end up flipped or on your side. You will be in the air for about a half second.

Greg

watch your time to accelerate to max speed - your robot will not be goign that fast instantly..... assuming you are using just the drills to drive, it usually takes 2-3-4 seconds to accelerate to 10ft/s, so it will probably take 5-6-7 or more seconds to get to your max speed, assuming you don't stall your motors :)

Tom

We'll be traveling 17ft/s on flat surfaces but there is no way we'll be going over the ramp at that speed.

Our team hasn't decided how fast we will want to be going on the ramp. We are constructing a ramp to test what speed we want the robot to be moving.

Has it occured to you that besides over the ramp, when do you need to go 17ft/s?

It will take you 2-3 seconds to get up to max speed (probably much more) and by then you'll have run out of possible room to accelerate (excluding ramp).

Speed is important this year, but there is a reasonable cap on what is pratical (unless you wish to attempt jumping the driver stations off the ramp :) )

Greg

BOXES!!?!??! what boxes?!?! i thought we were working with bowling balls!!

this isnt entirely true... We hit the goals in no more than three seconds last yr @ 13-14fps.

I guarentee you will not be able to turn at that speed no matter what drive system you are using. Keep that in mind

Cory

well..............
 

you didnt hear it from me, but Truck can make it up in somewhere between 5 and 15 seconds, depending on which gear we are in

hey, i think we have the same idea!
lol
well just have to wait and see huh?

We are gearing ours to run ~7meters per second . . . top speed, mind, assuming a coefficient of friction of ~1.2, we will still be able to almost slip our wheels. . . . .

Of course, 7 meters per second translates to around 21 feet per second, which I do understand it completely ridiculous (If we were to go up the ramp at 6.5 m/s we would remain airborn until we landed on the carpet on the other side) so we will probably program it to only get that fast when a 'safety' button is held down.

Looks like a fun year.

A couple of limiting numbers
 

A robot of 130 lbm with a friction coefficient of 1.0 on the carpet (a popular assumption) can accelerate at 1 g (given enough motor power, proper gearing, etc) or 32 ft/sec^2. That means it can achieve a speed of 16 ft/sec in 0.5 sec, during which time it will have traveled 4 feet. The drive train power (delivered to the ground) to accomplish this initial acceleration is 1,400 w.

If this bot is to hang a 180 degree turn and storm up the ramp to clobber the wall, the frictional force on the carpet to make the turn is: F = m * V^2 / R. The frictional force is again 130 lbf (mu of 1, 130 lbm 'bot), and a turning radius of about 4' takes the bot from park to about the center of the ramp. This result says the fastest the bot can corner is at about 11.3 ft/sec, at which point it spins out. At this speed it takes about 1.1 second to make the 180 degree turn, and then another 1.0 second to make it to centered on the top, if the same speed is assumed up the ramp.

So, physical limits to drive to the top say about 2 seconds, assuming the bot can deliver sufficient torque to (almost) spin its wheels from rest all the way up to 11.3 ft/sec. I will bet no autonomous bot will be able to hit the wall of containers in less than 3 seconds.

Dodd