View Full Version : How are you pushing down bridge?
midway78224
11-02-2012, 19:00
We are design a bridge mechanism and seeing what other people are using and what kind of success they are having
We have an one inch 1/8" wall aluminum tubing arm with a little under 90 degree "bend" in it with a free wheel on the end being turned by a banebot(I think?). I'm can't contest to the success, but from what I've heard it works beautifully.
Johnny_5
11-02-2012, 19:25
Marysville 3484 is pushing the bridge down with their robot. We lift the robot into the air and put our omni wheels down to push the bridge down.
TEAM F.R.E.D is using an arm on a window motor with a wheel at the end, having issues trying to get it to reverse just get it to go forward. I am sure there should be a way to make a relay go forward and reverse or am I mistaken.
legogeek24
11-02-2012, 21:29
@BOSS, I'm pretty sure relays are either on or off, with no direction. At least, I've never heard reversing a relay is possible.
@Johnny_5, how exactly are you accomplishing that? When you lift your robot in the air, aren't the bumper rules violated?
As far as my team, we're going to use our movable shooter/cannon to push the bridge down as we drive onto it.
As far as my team, we're going to use our movable shooter/cannon to push the bridge down as we drive onto it.
How on earth does that work?
TEAM F.R.E.D is using an arm on a window motor with a wheel at the end, having issues trying to get it to reverse just get it to go forward. I am sure there should be a way to make a relay go forward and reverse or am I mistaken.
@Leogeek24 @BOSS:
I must assume you are using a Spike type thing, because then if so there most definitely is.
The relay (at least the spikes) Flip their output polarity when given that certain command. Someone correct me if Im wrong
http://www.wbrobotics.com/javadoc/edu/wpi/first/wpilibj/Relay.html
If you look at the relay.direction stuff, there is like kReverse and kForward or something along the lines of that.
Originally Posted by legogeek24 View Post
As far as my team, we're going to use our movable shooter/cannon to push the bridge down as we drive onto it.
How on earth does that work?
What the..... Winning
We are programming in Labview so the Kforward stuff is Greek to me and our programmers. we are using the Spike Relay to control the motor. Any one got stuff on Labview.
Well, this may sound odd, but we are doing a wheelie and pushing it down the the front wheels...
We are programming in Labview so the Kforward stuff is Greek to me and our programmers. we are using the Spike Relay to control the motor. Any one got stuff on Labview.
Sorry no.
I mean this humorously, but me and the other main programmer are hard-core C++ & JAVA guys. LabVIEW makes at least us two shiver.
chi-town-biker
12-02-2012, 00:46
We are programming in Labview so the Kforward stuff is Greek to me and our programmers. we are using the Spike Relay to control the motor. Any one got stuff on Labview.
Here's a great source of LabView code snippets including code for relays. http://team358.org/files/programming/ControlSystem2009-/LabVIEW/ Thanks Robotic Eagles.
372 lives on
12-02-2012, 00:57
Marysville 3484 is pushing the bridge down with their robot. We lift the robot into the air and put our omni wheels down to push the bridge down.
my friend says his robot does this to didn't think it we be used by anyone else o.O
@Johnny_5, how exactly are you accomplishing that? When you lift your robot in the air, aren't the bumper rules violated?
[R01-2]....Note:..... A Robot in a transitory state of crossing onto/off of a Bridge or Barrier is not considered to be on a flat floor.
yeah team update 2012-01-20
MrForbes
12-02-2012, 01:18
When it's on the bridge, it's in a transitory state...but when it is lifting up and is not yet on the bridge, it might be violating the rule?
We don't know if ours works yet, we have to put some weight on the bridge and try it. Or at least draw a Free Body Diagram, so we can figure out if it should work. It's just an arm that pops down in front of the robot at an angle, and we drive the robot into the bridge, and hopefully push the end of the bridge down as we move forward. It's pneumatically actuated.
wireties
12-02-2012, 01:36
FORST Team 1296 is using a van door motor geared up a bit to push down an arm made with 1" square aluminum extrusion. The arm is 2-pronged, we are hoping a ball (on the bridge) might roll between the prongs and into the gatherer.
Team 3992 is using a 12" stroke pneumatic cylinder to facilitate a 90 degree retraction and extension of an arm.
Mike Norton
12-02-2012, 08:59
Van door motor gear down.
http://www.youtube.com/watch?v=BQ1mGk50OFc&feature=youtu.be
No need to lift your robot off the ground if down right.
MrForbes
12-02-2012, 09:53
FORST Team 1296 is using a van door motor geared up a bit to push down an arm made with 1" square aluminum extrusion. The arm is 2-pronged, we are hoping a ball (on the bridge) might roll between the prongs and into the gatherer.
You might want to make sure it will count as one appendage, not two. There's been a lot of discussion about this here and on Q&A. It's my understanding that a two pronged thingy is considered two appendages (and thus illegal) unless it's all one contiguous piece outside of the frame perimeter, even as it deploys.
wireties
12-02-2012, 10:09
You might want to make sure it will count as one appendage, not two. There's been a lot of discussion about this here and on Q&A. It's my understanding that a two pronged thingy is considered two appendages (and thus illegal) unless it's all one contiguous piece outside of the frame perimeter, even as it deploys.
It is one appendage leaving the perimeter that spits it into two equal-sized forks ... what on earth might contiguous mean in this context? It is solid, no articulating etc.
MrForbes
12-02-2012, 10:17
I wonder if pictures would help?
I think it means that the part outside the frame perimeter is all connected together.
But I'm not as imaginative as the GDC....
wireties
12-02-2012, 11:35
I wonder if pictures would help?
Out being welded but will post the cad later
I am also having a problem with "contiguous" (as mentioned in the G21 team update).
Our extension is sort of like a pair of salad tongs. One of the tongs is articulated. The two tongs do not contact each other directly, but they are both connected to one other piece. In other words, they cannot be deployed separately. They are both part of one mechanism that is deployed as a single unit. Is that contiguous?
Wups. I think this may be a better place for my question:
http://www.chiefdelphi.com/forums/showthread.php?t=102627
Depends on where they connect. If they connect inside the frame then it is my understanding that it is not a contiguous appendage. However, if they fork outside of the frame, then they are considered contiguous.
wireties
12-02-2012, 18:50
Depends on where they connect. If they connect inside the frame then it is my understanding that it is not a contiguous appendage. However, if they fork outside of the frame, then they are considered contiguous.
Look OK? And what if we add a little wheel on each fork?
https://lh6.googleusercontent.com/-Xz9FemA882c/TzhQHYIwGRI/AAAAAAAAAAk/t2XSu5WZzRs/h120/legalrampdevice.JPG
https://lh6.googleusercontent.com/-Xz9FemA882c/TzhQHYIwGRI/AAAAAAAAAAk/t2XSu5WZzRs/h120/legalrampdevice.JPG
::rtm:: Rule posting to follow:
[G21]
Robots may extend one appendage up to 14 in. beyond a single edge of their frame perimeter at any time.
Violation: Foul for exceeding size allotments; Technical-Foul for continuous or repeated violations.
These appendages are intended for use in manipulating Basketballs and/or Bridges. A Robot may have multiple extension devices onboard, but only one may be deployed at a given time.
[B]All portions of an appendage that are outside the Frame Perimeter must be contiguous with each other. Very brief violations of the contiguity requirement as a single appendage is being extended or retracted will not be penalized.
[/Blue Box]
Emphasis mine. From the picture, it would appear that it is contiguous within the frame, and the two forks of the appendage cross at two separate points of your frame. So, I'm not sure, but I do not believe this would qualify as a contiguous appendage.
wireties
12-02-2012, 19:13
::rtm:: Rule posting to follow:
Emphasis mine. From the picture, it would appear that it is contiguous within the frame, and the two forks of the appendage cross at two separate points of your frame. So, I'm not sure, but I do not believe this would qualify as a contiguous appendage.
Hey - thanks for looking at it. We sure appreciate the advice. It is hard to tell from this rendering but the cross piece is outside the frame when extended. It is is roughly (vertically) over the edge of the bumpers. The frame is all 1x1 Al extrusion - see it running behind the rendered bumpers?
TIA
372 lives on
12-02-2012, 19:15
Very brief violations of the contiguity requirement as a single appendage is being extended or retracted will not be penalized.
yeah.
MrForbes
12-02-2012, 19:16
So use pneumatics to actuate your appendage :)
Look OK?
Looks a lot like what we have. I guess now it depends on the definition of "very brief," how quickly the mechanism deploys, and probably on which inspector you get on game day.
And what if we add a little wheel on each fork?
I think the wheels are much less of a concern than the 2 prongs of the fork.
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