Re: What to do with autonomous
 

Chuck,

I'm curious about the diamond pattern. What is the reasoning behind this specific pattern? Also, how far apart are you placing them? And where? Are they at the edge of the 'bot? Centered in the front, rear, left & right of the 'bot? Or closer together? In the center of the 'bot? Toward the front?

Last year we had a linear array of 6 or 7 sensors across the front of our 'bot. It worked. (We used a heuristic assumption that we would be turning either to the right or the left, and then used the sensor input to keep us on the line.) But we decided it wasn't fast enough, and we opted to instead do a blind swoop out and back up the ramp.

Re: What to do with autonomous
 

Dave,

Did you mean non-standard? If you indeed meant standard, would you mind pointing us to some references? (We wouldn't mind, though, if you decided you wanted to share your non-standard methods too. ;))

Re: What to do with autonomous
 

is there anyone that is using multiple autonomous modes? if so i would like to talk about that.....my team is doing that and im just curious

Re: What to do with autonomous
 

Greg,
Looking down upon the diamond pattern, the top sensor is labeled North, right sensor is East...etc. N-S sensors are 6" apart. E-W sensors are 4 1/2". The N, E and W sensors are 2 1/4" from the diamond center. However, the S sensor is 3 3/4". The system is about 4" high.

The mechanics say we cannot have the space in the dead center of the robot drive system and that are line-tracking system can be placed slightly forward of center. So, we consider this S sensor to represent center of robot (close as possible).

The distances and angles formed by the internal angles are subject to change but this is a starting point.

Assuming the sensor data can be sampled fast enough in lieu of the robots rapid movement, it is possible by examining the on-off state of the four sensors several things....assuming you understand the starting position and orientation of the robot.

Our team (4 students and myself) will discuss this configuration in more detail and compare its results to other sensor layouts. We need only a few data points along this path to follow it (parallel it) successfully...of course we need to do this in less time than 15 seconds. :-)

Regards,
Chuck

Re: What to do with autonomous
 

We're not to that point yet, but judging by last year, (when we had around a dozen) we will have multiple auto modes.

Re: What to do with autonomous
 

I can't speak for the optimization in the custom circuit, because I never saw the code, but in the RC we used a simple lookup table. Doesn't get any faster than that.

Re: What to do with autonomous
 

I was thinking about this for our design as well. How did you reach the 6" rule? Arbitrary? I was looking at 2.5 times our accuracy. 2 times to account for sampling and .5 as a slush.

It's not a big deal, but I hate to not have a reason. :-)

Thanks.

Re: What to do with autonomous
 

Because we tried it and it worked the first time ;) Seriously, we chose 6" because we figured that it got us "close enough" to our point. Last year's game didn't require much precision, just a quick turn and dash up the ramp. If we were a couple of inches off it didn't really matter much. We wanted to run full speed the whole time and not worry about going back to a waypoint if we overshot it. We didn't do much testing, we just picked a box that was big enough to work. We made this number configurable per waypoint so changing it just required updating the range in our waypoint list.

Re: What to do with autonomous
 

great minds think alike I suppose...our team is running with the same idea in mind as well...

Re: What to do with autonomous
 

We're (I'm) thinking about it. You know, If you dead-reckon (Using nothing or just wheel encoders), your going to want to write 2 procedures, a left and a right, not to mention the dozens of other autonomous mode strategies one can write.

Re: What to do with autonomous
 

Well, the first part of our autonomous mode entails using Dead Reckoning to reach our 24' arm halfway across the field and...::censored::.. :D Am I kidding?

Re: What to do with autonomous
 

If you want to vote on a Poll, see a thread/poll named "What are you doing in autonomous mode?" created by me.

Re: What to do with autonomous
 

I've been living in a hole (my bedroom studing for exams) for the past week or so. First off, a question about the uber-accurate Wildstang Positioning System (WSP perhaps?):

1. How were you able to account for wheel slipping? This would occur when your robot would be pushed (while wheels were locked) or sliding down the ramp (for example). I'd immagine that such 'small' inaccuracies could addup to more then +/- 1-inch by the end of the match.

Back to our autonomous mode. I'm thinking (I'm the only programmer on our team) of using a IR seeking/dead reckoning hybrid. If at any point the beacon is blocked, dead (sorry, read 'ded.') reckoning would kickin. It would be adaptive, so the robot would continue in that direction until the beacon can be seen again. The dead/ded. reckoning system would rely on a counter to determine how much longer to go forward, not to overshoot the target.

I'm thinking of having a collision avoidance system; a set of sensors (sonar?) that would try to avoid obsticals (such as robots) by driving around them. It would also try to avoid the platform and the guard rail.

On a sidenote, herding balls will be interesting. I'd imagine that they'd go all over the place unless your robot has a neat device that would keep them under control :yikes:

Nevertheless, I'd like to hear more on other team's autonomous ideas.

Re: What to do with autonomous
 

We are working on a robot that hopefully will be able to do almost anything in autonomous mode. I have already put together the IR beacons and am working on the Banner Sensors. I do have a question about the banner sensors. Are you supposed to run it through the 5V digital output? We tried doing that and nothing happened. I think it needs 12V to run, but there seems to be no place to put it.

Re: What to do with autonomous
 

See here for details:

http://nrg.chaosnet.org/uploads/rts....ightsensor#rts