How fast is fast to get on the hill?
 

I figure that in the first 15 seconds, most teams will blitz for the middle stack...and speed will be a great factor in doing so...

So how fast do you think \ anticipate being able to get to make an attack on the center stack?

We are estimating that within the first 5 seconds, we will have knocked down most of the boxes on top, but I am wondering how fast other people might be able to get to it.

I mean, it takes our robot a few seconds to fire it's stablization harpoon into the rafters, warm up it's jump jets, and engage it's shock cannon... ;)

We plan on using a time travel device to have the stacks knocked over right when the match starts...no one will ever know!!

What about a team who may have a large arm to reach over the wall and knock over bins without ever having to move?!?!

Anyways....I'd say 1.5 seconds would be pretty fast...who knows how fast ours could go.

With our teams transmittion blueprints, they were estimating somewhere around 16 feet per second. I'm sure that some modifications will be made to change that along with certion factors.

we origonally wanted a 15ft/sec tranny... but then when you look at all the power you lose, and that no robot would really be able to go that fast and have someone contol it, and considering that the robot needs to make a 4' turn to get to the ramp, anything fast will just fall over if your tall. the sensors are also limited to how fast you can go, you would have to be dead reckoning and then if anything goes wrong the slightest bit you miss and take more time. getting up there fast is going to be harder than most teams think

we have no wheels
 

we are just using a large 25 foot arm that can reach all over the field. skrew a drvie train.

*laughs* we anticipate 2 sec's at least to deploy our selves.

:D

Re: we have no wheels
 

Wow, that is really ambitious, but if you guys can pull it off, then I fear you.

Well our robot is going to be around 7 ft/sec, but take into consideration that it is not a straight dash, getting to the boxes require turning and going at a speed much lower than the robot's potential speed =(

Not really... we are doing it in a way that requires very little turning... I'll let you think of how.

Cory

We are shooting for 6-6.5 F/PS. We were originally thinking 8-9 but we realized that if got into a pushing match, the motors would stall, breakers would trip etc.

shift gears, then you have no problem. Shifting the drill motors with a servo is very easy to do, and worth it even though you need to stop.

Cory

Theoretically 16ft/s would work well but think about how long it would take you to accelerate. When they ran the numbers for our tranny, I think they dropped the top speed in order to accelerate faster.

Personaly I feel that competitive teams will hit the wall in <7 seconds. On the other hand an arm or any "long shot" device could knock it down in <5.

I see competitive teams hitting the wall in 3-5 sec. Oh yeah, ever see kingman last year? hit the goals in 1-2 sec @ like 18 fps. They had incredible acceleration. Biggest disadvantage I see is probably not being able to turn due to friction at such high speeds. We went at around 13-14 fps last year, and turning at full speed was impossible.


Cory

With a front dually, rear swivel caster design, we aren't "Trapt" with the confines of not being able to turn on a dime, yet we achieve an amazing 16.5 fps on level ground, and should achieve over 13 fps over the ramp. We're light, and heavy on traction. :ahh: Pun!

It's all on how many motors you use and how you gear it....

Pair up the CIM and Drill motors....use reduction from the CIMs to the drill running on high, gets some good speed....with quite a bit of torque....

There are similar match-ups, this is just one I know, fairly easy to do too.

Time travel, Big Arms, And fast speeds
 

its amazing how many different ways there are to knock down the boxes that dont involve wheels... of course this is a creative and most difficult task to pull off... im guessing most teams will have speed and depend on it for there control of the center stacks.... but i wanna see the teams that will use arms the center stack....

of course no team wants to tip there hand and show the rest of the world wuts up there selves but i really wanna know


Pushing

Moving walls

Large Over Extending Arms

Time travel:p

wut other ways of getting the stack have teams developed?

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

Slight Problem
 

We were planning to o about 10.5 F/sec, but the main problem is what if you and your adjacent opponent both go up the hill in the first 15sec your white lines will intesect at the top of the hill. So it all depends on who gets to he top first, and still has enough power to push as many boxxes to there side as they can.

Thats the only problem I forsee, the only way to get around it is to program your bot to go up the center of the ramp instead of up the side. The middle holds alot of points that can go either way!

Re: A couple of limiting numbers
 

Good, now I don't have to work this out for myself :)

Isn't 1400 watts more then the motors can deliver? Maybe if someone uses stored energy in springs (though a team update kindof rules that out).

I forsee the biggest problem with speed being control. It would be very difficult for a human to make that turn that accurate every time, I see no way to do it without the line with the computer (and lets see you track a line at 10fps).

Greg

1400 watts/12 volts=116.7 amps.
Good luck.

Umm, programming?
 

Like was mentioned before, the challenge here is NOT how fast your robot can move.

Anyone who has worked with a feedback system (line tracking) will know that it will be very difficult to enable the robot to travel at full speed through the entire course of the turn and still hope to end up facing the boxes on top of the ramp.

Effectively, it would be VERY difficult for a robot to travel beyond 6-7 ft/sec and hope for the program to keep up with the curve.

Anyone that has worked in Lego-League will know that too basic a line tracking system makes your robot bounce left and round on the line, and a dead reckoning system with no feedback would be very difficult to get consistant with every condition.

Instead of the discussion being robot speed, perhaps it should shift to the real purpose of the challenge, sensors and programming :)

Location of Boxes
 

Did anyone stop to think that hitting the boxes at full speed is likely to knock them over your robot and into your opponents scoring zone?

If you do it right, it won't fall backwards, and yes, that was our teams first concern about building a short bot. :-D

fastest time, most bins to our side
 

We will be "there" faster than you can realize your robot is one, and a great deal of bins will be on our side very quickly...we have an arm specifically designed for this process (minimum, quick movement into position) that is very fast and strong, and just the right length. And we already have the code written to control it during autonomous (and for that matter human control) mode - its sweet! How many teams are using arms? How many of these are just long enough to get over and knock some bins? How many are uber-arms that go anywhere and do anything?

190's robot should be able to reach the top in 3 seconds this year. Control won't be a problem either. I can't say much more than that.

psssch
 

Ramp? What ramp?

:D

Maybe, if a group of programmers got ambitious, one team will make an inertial guidance system. :p All it would take are two of the yaw sensors, and good integration. However, it would take a huge amount of programming.

it would take a few more sensors than just yaw rate sensors..... thats all i'll say

JUST HOW FAST???
 

rly, rly, RLY fast:D

We did some math here and figured that if your robot goes over the ramp at 16+ f/s your robot will "fly" over the ramp. Just something to keep in mind for some of you trying to achieve a very fast speed.

Thats why we designed our robot to knock over the blocks a certain way. I haven't the foggiest idea how fast our robot will be. I haven't had the time to calculate the speed yet. My one calculation made it around 5mph max.

bah..why bother with the bins... if so many people are going to knock the wall over at the very beginning, I say just wait until the mess on the ramp clears....... and just collect the bins you want!:p

OMNI DRIVE OMNI DRIVE OMNI DRIVE OMNI DRIVE OMNI DRIVE OMNI DRIVE OMNI DRIVE OMNI DRIVE OMNI DRIVE OMNI DRIVE OMNI DRIVE OMNI DRIVE OMNI DRIVE OMNI DRIVE OMNI DRIVE OMNI DRIVE OMNI DRIVE OMNI DRIVE OMNI DRIVE OMNI DRIVE

PLEASE BE OMNI DRIVE!

I really want to see someone do omni drive this year

Greg

Since i'm sure most teams have the same methods of arms and quickest turning methods, i'm interested to see how the first 15 seconds in auto mode go, and what method is the most effective

~Amy

we are up to about 8ft/s and have no problem with tourque and stalling, partially because the worm gear system we have prevents back driving and it works great. plus we also have a large foot that walks up the bridge thingy...



Bad

Anyone want to fill me in on how fast y'all are planning to accelerate? And how do you plan to compensate for going at such high speeds around corners?

Has ANYONE thought about the collison between two alliance robots as they make the arc at the bottom of the ramp travelling at 12-20 ft/sec? Many alliances will never get to the top! Many robots will go home in pieces. Ya got to think of the WHOLE game.

Just Blow Them Down
 

Why drive over the ramp - just knock them down from the starting position. Why waste the time.

Yo Ho Blow the Boxes Down.....:confused:

The bagel wall of doom
 

Beware of the fan jet bot

but its a fine match to our Bagel Wall of doom

The game is over in three seconds for us...
 

We've already ended the game within three seconds! Looks like u have to become quicker! Muahahahahaha:eek:

You tweak the program just right so you are on two wheels without tipping, 100% of the time :yikes:

FAST!
 

fast is whatever we say it is

Our robot can go about 12ft/sec and can get to the ramp in auton mode in just about under 3 seconds, pretty impressive don't you think? :)

Hmmm... I am surprised at all the talk, and no one really willing to give a number.

When we tried out our autonomous programs, we were able to get up to the bins in about 4 seconds. We didn't formally time it. We used several different methods, but the four seconds is running at half speed or less for accurracy until you are lined up on the ramp. Then we accelerate to go up to the stack. Oh, BTW we are only an 8 ft/sec 'bot.

And yes, if you hit the stack low and fast it sends many bins the wrong way. If you hit the second bin high and not too fast, the entire stack tips over the way you want it to.

My question is... Now that you and three other robots are jammed into the space at the top of the ramp with ten seconds left in autonomous, whatcha gonna do now? Frankly, we haven't decided for sure whether we should let ourselves get caught in that tangle.

I think the swing arm aproaches are great, and avoid other problems. My only question for teams doing that is what happens to your crank when your swinging arm encounters a stopping force. It is one thing to test a swing arm against bins, and entirely another to test against bins being pushed the other way. I am curious whether anyone actually tried that.

DPC.

Good question. We went to the Chatsworth Scrimmage with our "swing arm", but our opposition in those matches didn't reach the top in time to oppose our arm. We will have to wait for the Arizona regional to find out what happens when a really fast robot, or another arm like Team 234's, pushes against our arm rotation.

Team 234 will be competing this weekend at VCU, and although their arm is very different than ours, I am sure our team will be interested to see how their arm does in actual competition.

our bot is 6fps and hits the ramp in 4.034 seconds.

we have yet to see how this works out

Top in 2.2 secs
 

We have tested and repeated several times now and we get to the top in an average of 2.2 seconds. Our fastest was 2.0 and our slowest was 2.4 (averaging all the trials). When I say the top I mean contact with the bins. We stopped the time as soon as the robot made bin contact. We have an identical practice bot and are tweaking, because my calculations show we should be at 1.9 seconds. I know what you're thinking, but let me just say this: I used differential equations to model the behavior of our robot on this year's playing field and so far everything except the final time is mapping within a few percent.


-Paul

P.S. - we don't want to be king of the hill, just king of the bins.

Re: Top in 2.2 secs
 

I just looked at a picture of your robot. I am amazed that you can get to the bins so fast. How do you avoid tipping over going around the corner?

If we qualify for the championships and meet up with you in Houston, I hope we are on your team.

Control won't be a problem? I watched the videos from UTC matches it looks like you need a lot of help. Not once did you make it to the top under the auto mode.

You might make it to the top in 3 seconds but it has not happen yet.

And by the way it looks like if someone puts a bin in front of your robot the robot does not do well.

I see you are a little top heavy. Having a robot be able to flip you now is not a good thing.

Thanks for the compliments.

Just to let you know, our "INS" was not installed at the UTC scrimmage, we were running off "dead reckoning" - the reason it looked like a bin gave us problems was really because the program was not done correctly.

If you watched all of the UTC matches, you would see that in our final match we were able to successfully get to the top of the ramp under autonomous, in low gear.

If you are going to post something negative about a robot, at least have correct information.

Thanks, looking forward to seeing everyone tomorow at BAE

Tom

I'm good friends with a member of 190, and as he explained several things not just ins were not in order. they weren't truly topheavy, but their wing mechanism wasn't collapsing as designed. WPI has an excellent robot, and it's fast, however.... I do think that 3 seconds is overestimating yourselves again. Chris said about 5 seconds.

At the UTC scrimmage they took 10-12 seconds in dead reconing, and were the only bot to knock down ~70% of the stack. They were ahead of many teams even then.

871 is in about the same time range of 5 - 5.5 seconds.

Great job guys, i wanna see this INS in action. and how you guys did that after or at houston.

The bot from Oakwood (Ralph II) should be able to get to the stack in about 1.5 seconds based on previous testing before shipping. We dont have to move so we dont have to be horribly fast. We should be able to knock down about 80% of the boxes if we measured angles correctly. Anyways, hope to see a lot of you at SoCal. Peace.

Our robot uses dead reckoning and makes it to the top in 3 seconds and can knock about half of the totes into our scoring zone. We were able to see this happen at UTC but our program was not quite finished so we didn't get as many boxes as we had hoped.

How many people are actually able to get the top in under 5 seconds, and are you using line tracking or dead reckoning to get to the top?

DougHogg,

It looks like we are top heavy, but in fact 95 lbs (including battery) of our robot is located below 9 inches. The framework above is basically aluminum tubing, with the exception of one motor.

We have steering wheels that control our circle diameter and dynamic wheel speed control to slow down the inside wheels based on steering angle. This reduces the amount of skid that our robot has when cornering.

-Paul

wow, anything under 3 seconds is very impressive

and very useful

my question is, how many autonomous modes work for people?

from what i hear, not very many

We estimate we get there in about 4-5 secs. Our dead reckoning auto mode works perfectly on a scale field (with the correct surfaces) but has not been tested in actual competition. We will know in less than a week.

We have 7 fully functional autonomous modes that have been tested but werent perfect when we shipped due to the lack of a full field to test on. our last one is in its final stages right now but we wont know if it works till next Thursday at the UTC competition.

So, how are on-the-ramp times looking after the first real day of competition?

Here is what I can tell you from the NASA/VCU regionals.

We were lucky to have a fairly repeatable dead-reckoning auton mode. We hit the ramp pretty consistently in about 5-6 seconds, although, I must admit that due to the nature of competition I never thought to time it - we had more pressing concerns. Many teams had similar time. Maybe 3-5 were faster that we, and then there was 234 with that incredible arm. (great job 234!!)
[we actually had one match where we hit the stack about a half second after 234 hit the stack with there arm from diagonally across the field - they got more bins than we did from that start]

There are also about 20% of the teams with very slow auton mode, but many were still effective.

If I had to sum up, it was only in the elimination rounds where you really started to see more than two robots hit the stack early in auton mode. Also, it is my opinion (quite the opposite from my original thoughts 6 weeks ago) that getting all the bins early does not correlate with winning the match. There are a multitude of small bots that can push bins around, and many were flying out of the field just due to impact.

We had incredible luck, a great driver, a very tough bot and two remarkable alliance partners (Props to 388 from W. VA and 395 from the Bronx!!!!!!) and we won the finals.

All I can say is strap in tight, it is an incredible game!

Beware the Bomb Squad
 

Most robots at the St Louis regional had ineffective autonomous modes. My team was slightly better than average when our dead reckoning worked correctly, which was less than half the time. When things went well, we hit the wall in about 6 to 7 seconds and took two or three columns over with us.

The fastest robot, by far, was Team 16 Baxter Bomb Squad. They got to the wall in 2 to 3 seconds and took out 3 or 4 columns, consistently match after match.

And then there is 547. Their robot isn't any faster than ours, but if it gets there first, it sends the entire wall to its side. A truly awesome sight.

St. Louis was great. thanks to all the teams who helped us the whole way. thanks to team 936 and 476, our final alliance partners who did a great job and should be extremely proud.

we had a very reliable auto. mode. it took about 7 seconds to knock down ALL 29 bins. we knocked them all down 5 out of 8 times during the qualifying rounds. once, team 45 beat us to the hill with a very fast and effective auto. mode. another time, we lost our auto due to our human player not getting back to the mat on time, and once more when our arms didn't deploy, but thanks to cory, our driver, and amy, our operator, we managed to do great and be consistent the whole time. also our backup drivers, kreig and zach did a teriffic job along with our human player Jess, and mentor, nick. over all we were very successful at St. Louis with a final ranking of 9. we also won a gm industrial design award. I would also like to congratulate the winners, team 171 and their alliance partners.
BBS (team 16) had the fastest auto. (about 2- 3 seconds to the top and another 1-2 seconds to knock down over half the boxes), and the fastest bot, with excellent drivers. there are many other teams that did great and many more that helped us out during the competition and we thank them.

254 consistently got to the boxes in 2.5-3 sec at Sacramento. There were four or five teams that could consistently get to the top in autonomy. Our robot was much slower to the top than expected, but we made it there right before the human control mode kicked in, setting us up perfectly to hit 2 rows, turn and hit some more. Our linefollowing/gyro autonomy earned us the Delphi Driving Tommorow's Technology award, which made us all extremely happy.

Cory

234's Arm
 

I'm a member on team 234. I didn't get to go to the Virginia regional due to a jazz band contest, but I did watch the last qualification round and the finals on the webcast. From what I saw our arm did what we wanted it to do. However, we had a little trouble with dampening the pneumatics on the arm when we threw the elbow out. This cause us to have to wait a few seconds to start the rotation. I think that if we wouldhave had our programmer there we could have made our arm even faster. In the finals we hit the wall about the same time as another robot and that robot took a few of the stacks we were going for. We lost the match! The second match we didn't play. I don't know the circumstances of that yet. I will find out on Monday when I go back to school. Maybe at the Arizona Regional we will get our arm working even faster so that no driving robot can get up the ramp at the same time that our arm gets to the boxes.

I can't wait to see any other great arm bots out there. And I can't wait to see what happens when we come up against one. I think our arm can take the forces but I am not sure how well. Our engineers are great!!!!!!!

58 estimated 5 seconds, and we were the first to the stack in every single match we had (about 15 in all), with a couple robots flipping over because they hit the boxes while we were on the other side. I believe we could have shaved a second off, just by not driving back as far in autonomous, anyone who watched us could see we drove back a ways, it worked though, consistantly.