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-   -   Shooting from opposite side of the field (http://www.chiefdelphi.com/forums/showthread.php?t=99561)

Djur 09-01-2012 19:52

Re: Shooting from opposite side of the field
 
Quote:

Originally Posted by davidthefat (Post 1101000)
.... What motors are a good alternate for the shooter? Fisher Price ones?

Here are some comparisons of torque and rpm at maximum power.

CIMs: 45.00 oz-in; 4614 rpm.

BaneBots: 11.69 oz-in, 7300 rpm.

Fisher Price: 35.7 oz-in; 10500 rpm. (Model 0080-0673)

davidthefat 09-01-2012 19:54

Re: Shooting from opposite side of the field
 
Quote:

Originally Posted by Djur (Post 1101014)
Here are some comparisons of torque and speed/volt.

CIMs: 343.27 oz-in stall torque; 443 rpm/volt.

BaneBots: 61.1 oz-in stall torque, 608 rpm/volt.

Fisher Price: 75.4 oz-in stall torque; unknown rpm/volt. (Model 0080-0673)

Darn you GDC for limiting the usage to only 4 CIMs... But the FP is the next best thing.

Djur 09-01-2012 20:14

Re: Shooting from opposite side of the field
 
Quote:

Originally Posted by davidthefat (Post 1101016)
Darn you GDC for limiting the usage to only 4 CIMs... But the FP is the next best thing.

Maximum 2 FP, 4 BB. If you compare 2 BB to 1 FP per pitching wheel, this is what you get.

(Models used: BaneBot M7-RS775-12, Fisher Price 00801-0673)

BB: 2 * 11.69 oz-in = 23.38 oz-in @ 7300 rpm (Max power)
FP: 1 * 35.7 oz-in = 35.7 oz-in @ 10500 rpm (Estimated max power)

Fisher Price > BaneBot

Also, I should have put the values in that list at max efficiency. Fixing....

Siri 09-01-2012 20:46

Re: Shooting from opposite side of the field
 
Just a reminder that some people don't always let the mere quantity of motors control the number of devices for which to use them. ;)

(Of course, if you're planning on shooting while driving, this could be more complicated.)

Djur 09-01-2012 20:54

Re: Shooting from opposite side of the field
 
There is a maximum of 22 motors... 4 CIMs for drive, 2 FPs for shooting, and 2 BaneBots or something for aiming a turret is only 8 motors.

DavisC 09-01-2012 21:30

Re: Shooting from opposite side of the field
 
1 Attachment(s)
How practical does this look, what do you think of it?

For the most part the ball enter the back of the robot is picked up by a belt which uses force against plastic/rollers to move it upward and to the launcher. it gets to the launching part (motor sets B & C). Then Set B gets it moving to a good speed so that when it hits Set C, it is propelled even faster.

I tried to mark the ball path with a consistant line and marking it with arrows to get an idea of speed.
What you think? (sorry for the crude drawing, and not being to scale...)
Davis

pfreivald 09-01-2012 22:42

Re: Shooting from opposite side of the field
 
Quote:

Originally Posted by Ryan_Davis (Post 1101007)
That's frightening. :ahh:

Do the math on a feeder bot actually being a shooter bot that coincidentally only feeds even most of the balls shot.

Assuming half of the missed shots from beyond the barrier are picked up by your alliance and the other half are picked up by the opposing alliance, what do you get?

25% shot accuracy yields a 1.5-1 advantage over your opponents.
33% shot accuracy yields a 2-1 advantage over your opponents.
50% shot accuracy yields a 3-1 advantage over your opponents...

And that doesn't take into account that every ball you score as feeder is a ball your alliance partners don't have to go get and score, which gives them time to do other things (like either play defense or go scoop up balls to make that ratio better than 50-50.)

Now mind you, the distance error in a shot is approximately x*tan(theta), where x is the distance from the hoop and theta is the number of degrees between the perfect shot and where you actually shot. This translates into a maximum tolerance of about one degree at half court (ignoring distance discrepancies). Crazy, unlikely, almost unbelievable -- but we're going for it. At the very least, it should improve our shooting from the key!

mdiradoorian 09-01-2012 22:56

Re: Shooting from opposite side of the field
 
Who thinks that is it possible for a human player to make the shot from the corner? (doesn't matter which basket)

pfreivald 09-01-2012 23:20

Re: Shooting from opposite side of the field
 
Quote:

Originally Posted by mdiradoorian (Post 1101250)
Who thinks that is it possible for a human player to make the shot from the corner? (doesn't matter which basket)

Possible, but not likely enough to make it much of a consideration in the game, methinks.

IndySam 09-01-2012 23:29

Re: Shooting from opposite side of the field
 
Quote:

Originally Posted by mdiradoorian (Post 1101250)
Who thinks that is it possible for a human player to make the shot from the corner? (doesn't matter which basket)

I know it's possible. Our best shooter made it from half court on our basketball court twice without much practice and that was in a hoop at regulation height.

I think you are going to see this a lot more than you think.

dtengineering 09-01-2012 23:36

Re: Shooting from opposite side of the field
 
In '06 we could score from half court. In fact our autonomous mode was simply to have the driver line up the turret when they placed the robot, then spool up the motor (an FP, direct drive to a 6" wheel if I recall) and fire away.

We could have hit from further out, but the game had a built in speed-limit for the balls, so we were pretty much at maximum range.

Frequently, however, the balls would go in, but the massive backspin would actually toss them out of the aim high goal.

Backspin will be useful for stabilizing the flight of of the balls, but will also create lift, altering their trajectory and... in this game, unlike Aim High, will likely aid in scoring if you use it to bounce shots off the backboard.

My experience, however, after spending six weeks building a pan-tilt shooter that could (once you lined it up right) hit from anywhere was that in the time it took us to get our aim right, teams with far simpler shooters would drive in and hit ten shots from close range.

This year's target is smaller... there is nothing wrong with going for the slam dunk or lay-up approach... particularly if you have a hopper on the back of your robot that allows your "shoot from the other end of the court" colleagues to fire balls into your hopper (much larger than a goal) so you can finish the play.

Jason

Andrew Lawrence 09-01-2012 23:45

Re: Shooting from opposite side of the field
 
Quote:

Originally Posted by IndySam (Post 1101287)
I know it's possible. Our best shooter made it from half court on our basketball court twice without much practice and that was in a hoop at regulation height.

I think you are going to see this a lot more than you think.

I think they should include in one of the updates that baskets made by the human player in the last 30 seconds of the match are worth more; maybe like the normal score +2, so as not to get ahead of autonomous, but to still allow teams to score while balancing on the bridge.

Ninja_Bait 09-01-2012 23:48

Re: Shooting from opposite side of the field
 
Quote:

Originally Posted by SuperNerd256 (Post 1101302)
I think they should include in one of the updates that baskets made by the human player in the last 30 seconds of the match are worth more; maybe like the normal score +2, so as not to get ahead of autonomous, but to still allow teams to score while balancing on the bridge.

They can't. This year the scoring is entirely automatic, hence the photogates at the baskets. There's no way to distinguish between a ball thrown by a human and a ball scored by a bot that will also allow for immediate scoring.

Grim Tuesday 09-01-2012 23:50

Re: Shooting from opposite side of the field
 
Quote:

Originally Posted by IndySam (Post 1101287)
I know it's possible. Our best shooter made it from half court on our basketball court twice without much practice and that was in a hoop at regulation height.

I think you are going to see this a lot more than you think.

But did he have an 8' barrier in front of him?

Gray Adams 10-01-2012 01:31

Re: Shooting from opposite side of the field
 
Quote:

Originally Posted by Brandon_L (Post 1100567)
but we are limited to 4 CIMs this year, and about 99% of teams are going to use them for drive.

http://www.andymark.com/product-p/am-0932.htm

http://banebots.com/p/S24K-C1-7

So the question becomes, FP or banebots.

And also, if banebots, one gearbox or two hooked up to a single wheel shooter? (Limit 2 FP, 4 Banebots [R65], and correct me if I am wrong but each box takes two motors)

If you plan to camp in the corner and launch balls, you could probably get away with 2 CIMs in your drive. You're not going to speed past anybody, nor are you going to push them, but who cares when you're going to drive into the corner, wait until the end, and then drive up the ramp. If you do autonomous right, you'll never even touch an opponent.


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