Chief Delphi

Chief Delphi (http://www.chiefdelphi.com/forums/index.php)
-   General Forum (http://www.chiefdelphi.com/forums/forumdisplay.php?f=16)
-   -   Elevator robots why didn't you.. (http://www.chiefdelphi.com/forums/showthread.php?t=36781)

rowe 30-03-2005 22:27

Re: Elevator robots why didn't you..
 
Quote:

Originally Posted by nukemknight
Do your teamates have reliable autonomous programs that use the camera? If they do, and your robot picks up the vision tetra placed in front of you, your teamate will either track the tetra you pick up, or possibly run into your robot while trying to pick up a different vision tetra. In either case, this would more than likely delay your teamate (and your own robot???) from reaching a goal in time to cap it.

If you alliance partner has a reliable autonomous program (more so than yours) I'm assuming you would be able to communicate this before the match and switch your autonomous to something that doesn't interfere with the other, and if yours was more reliable, they would switch theres. That seems like the most logical solution to that problem.

doop_forces 30-03-2005 22:45

Re: Elevator robots why didn't you..
 
I think the reason teams don't cap vision tetras in autonomous is because the chance of successfully capping the tetra would be a less than 1/4.

The tetra's are placed in certain locations in the beginning of the match but the Field reset people are only human. Therefore, the tetras may be offset a bit which could throw off a robot.

Furthermore, if a robot does obtain the tetra then the robot still has to make its way over a goal and cap it. Robots starting out with a tetra couldn't even cap every time.

MFS766 31-03-2005 00:30

Re: Elevator robots why didn't you..
 
Quote:

Originally Posted by Collmandoman
I've been really curious as to why the elevator robots didn't just dead reckon putting a vision tetra on the center goal.. you have a 1/4 chance one will lie in the middle path.. drive (through both possible vis tetras on the center row) then raise then drive alittle more and drop - back away

Our robot is not an elevator robot but we are going to work on a blind vision tetra cap. In Sacramento, we were able get our robot to knock off the hanging tetra, and in silicon valley, we were able to cap a non-vision tetra. We were able to do this because our robot was so reliable. We ran out of things to do in the pit between matches so we gave the opportunity for our programmers to shine. Our capping program at silicon valley helped us get the GM Industrial Design Award. At Atlanta, we anticipate, plenty of time to add to our current program and create a blind vision tetra cap. Why would we have one? If all of our robots can knock down the hanging tetra or cap the non-vision one, one robot has to sit out in the middle. So if our robot has a chance of capping a vision tetra, it is still better than doing nothing.

ldeffenb 02-04-2005 17:03

Re: Elevator robots why didn't you..
 
If you'd like to see videos of two *very* close attempts at the center goal with a vision tetra (along with the initial tetra!), download "20050312 Vision Tetras.torrent" from my BitTorrent tracker at http://ldeffenb.dnsalias.net:30049. Remember, this was our first and ONLY regional competition (we're not a rich team).

We have a camera on board, have code to identify all 8 possibilities from each of the three starting points, drive paths to acquire and deliver those tetras to the center (and, in some cases side) goals, only to discover that our drive and lift were slow enough that we only had a chance at delivering the center 2 positions to the center goal.

That's when we decided to use the motion to handle the initial tetra as well (hey, 3 points and owning the center in autonomous is better than 0 points looking like a sitting duck). (Want to watch painful replays? Download "20050310-12 386 Auto SloMo.mpg.torrent" for slow motion reruns of all of our automous runs. They'll make any software team cry from the effort wasted when software meets hard(ware) reality!)

We now know that we're tilting too far towards the goal and that our lift motor backdrives (watch closely in QF4-2) and those problems will be corrected in Atlanta. If no one does it before that, it'll be a race to the finish as far as Team Voltage 386 is concerned!

We *will* do it (vision tetra onto center goal) in Atlanta!

Lynn (D) - Team Voltage 386 Coach and Software Mentor

PS. Download a BitTorrent client at www.BitTorrent.com or www.BitTornado.com (Windoze only).

PPS. If you download 20050222 Tetras.torrent, you'll see us actually do a 2 or 7 vision tetra in autonomous just before shipping.

PPPS. We *will* succeed in Atlanta! Look for us. We'll be the team waving the Tiki Trophy!

PPPPS. Our team statistics expert had calculated the 46.4% probabilty just before we shipped to help the software team get out of the dumps based on the slowness of the robot after we worked hard at programming all possible combinations of starting and tetra positions and target center-line goals. We had hope! And with an updated tilt gear to be installed in Atlanta, we *will* do it!

ldeffenb 02-04-2005 17:17

Re: Elevator robots why didn't you..
 
Quote:

Originally Posted by Collmandoman
I've been really curious as to why the elevator robots didn't just dead reckon putting a vision tetra on the center goal.. you have a 1/4 chance one will lie in the middle path.. drive (through both possible vis tetras on the center row) then raise then drive alittle more and drop - back away

Even with the 46.4% chance that there will be a 2 or 7 vision tetra, it is *extremely* hard to get a robot to drive straight, even with encoders and gyros, for 27 (actually about 20+) feet.

You do the math, if your 9" diameter wheels are off by 0.1 inches, how much horizontal difference will there be between the left and right sides after 20 feet of matching wheel rotations? What position will your robot be in when it drives through the positions 2 and 7 and what will the orientation be when you arrive at the center? What tolerance do you have to actually get the tetra on the goal in a scoring (meaning you can't be touching it) position?

And can you do it all in 15 seconds?!?!?!?

Contrary to Team 25 (offering the Tiki trophy), we *know* it *can* be done, but a bunch of semi-controllable variable have to align *after* the 46.4% has been achieved!

Lynn (D) - Team Voltage 386 Software Mentor


All times are GMT -5. The time now is 05:17.

Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.
Copyright © Chief Delphi