Air Defense System

[davidthefat]

Originally Posted by Ninja_Bait

If you can hit a ball with another ball, you should:
a. work for NASA and:
b. use your impressive engineering and programming skills to make a killer offensive robot instead of a defensive one.

I agree. Even tracking the ball in mid air and predicting where it is going is unbelievable for a highschool student to do. Keep in mind the delay of the camera and you might only get the ball in one frame. You would have to differentiate it from all the other balls on the field and then calculate its projectory, then calculate the angle of the shooter and shoot, all within a split second.


Even with the air idea, not feasible.

[Nuttyman54]

971 tested this idea in 2006 and found it was not feasible. The most effective method was an electric leafblower, and that only deflected the balls an appreciable ammount when the stream of air closely tracked the ball for several seconds. You would have to use then best motors in the kit, sacrificing your drive train, to even come close to the power required to achieve this, and even then you would need an incredibly accurate tracking method to make it work. This also means in a volley of 3 balls, you can only deflect one at most due to the time duration of deflecting opportunity

[bhaidet]

I think we should get a GIANT hair dryer and capture the balls midair with the venturi effect (like ping pong balls on normal hair dryers). LOL

and on a realistic note, there was a team with a fan my freshman year (to navigate the lunacy regolith). might have been delphi elite ? it was a huge (about 2 foot) wooden-bladed fan on the back of the bot with a cage around it. I have not yet picked up one of these "basketballs" so I don't know how dense they are and if a fan could actually affect it . This would be AWESOME but you would need a fan to take up your entire horizontal dimension and probably add a cowling besides to focus the blast/stream. if you had a 2 foot fan you would have 2" all the way around for a cowling I think.

[Samk]

Originally Posted by Thermal

I do not see anything in the rules that would directly prohibit a team putting a swamp-boat esque shrouded fan powered by a cim on the top of their robot pointing directly up (or at an angle maybe 20 degrees from vertical). A 20" diameter fan powered by 2 cims would be.... scary. Possibly effective, but i'd have to see a prototype. As a hunch though, i'd say it'd be very effective at blocking the middle tier goals, but probably ineffective at changing the path of balls aimed at the top tier goals (unless you're right in front of the robot lobbing for the top rung and can impact the balls motion right as it leaves the robot)

I'd like to see someone try to get a giant fan like that inspected, something tells me that would not be amused, haha

[Spen.M.P.]

what if instead of a large fan blowing a 2 foot circle of air, you funnel the air into a thin, long stream and use it more like an air knife, or an air cleaner on production lines. Maybe two 3 foot fans with all of their air angled up into a stream?

[Ernst]

Have any of you ever used an AirZooka?

You may want to consider a giant AirZooka.

[davidthefat]

Originally Posted by ZehP

Have any of you ever used an AirZooka?

You may want to consider a giant AirZooka.

I have used a giant one of those (the big trash cans) it just does not produce enough force. It just messes up someone's hair. Nothing else.

[Lil' Lavery]

Originally Posted by Ninja_Bait

If you can hit a ball with another ball, you should:
a. work for NASA and:
b. use your impressive engineering and programming skills to make a killer offensive robot instead of a defensive one.

Why are offensive and defensive robots mutually exclusive?

Originally Posted by bhaidet

and on a realistic note, there was a team with a fan my freshman year (to navigate the lunacy regolith). might have been delphi elite ? it was a huge (about 2 foot) wooden-bladed fan on the back of the bot with a cage around it.

Based on your description, that was likely a different Delphi-sponsored team, Team 45 the Technokats, rather than Team 48 (Delphi Elite).

[Nuttyman54]

Originally Posted by ZehP

Have any of you ever used an AirZooka?

You may want to consider a giant AirZooka.

We tried that too, up to trash can size. Still less effective than the leafblower, and requires impeccable timimg.

[Ninja_Bait]

Originally Posted by Lil' Lavery

Why are offensive and defensive robots mutually exclusive?

They're not; I just meant that the focus should be on the former, not the latter, especially with the hypothetical skill set involved.

[shuhao]

We also thought about it.. however this is extremely complicated to do as you will be needing to track and hit a moving object in mid air.

I mean.... shooting a static object is hard enough as is.

[VKP]

Our team experimented with fans today and found that using 6+ of the KoP fans (side by side and in a row) do absolutely nothing to balls passing by them.

It looks like compressed air would be the way to go for this defense method.

[Spen.M.P.]

Would 11.6cfs (700cfm) do the trick? I believe all you would need is two CIM motors.

[Rocketeeringer]

The reason we discarded the ball idea was because it means we are limited to 3 intercepting shots (you can only possess 3 balls), whereas the air system would have unlimited ammunition (disregarding battery life etc.), and like Ninja_Bait said, we would go work for NASA

A cannon may not be effective enough given the pneumatic parts allowed (valve is too small i hear and the max psi is too low), fans will be hard to make large and safe while effective enough, and leaf blowers have massive draw on battery.

One idea we had like what Spen.M.P. suggested of an air knife was to have an industrial blower that they use for clearing milling machines and the like, for a concentrated stream.

And like davidthefat, Nuttyman54, and Ninja_Bait said, the difficulty of tracking a ball traveling at more than 10 fps with a lagging camera would be incredibly difficult, and you're paying the opportunity cost of the best motors to power a limited range defensive system that may not be able to protect the top hoops, and the amount of training required for drivers could be more than if you trained them to just shoot baskets.

One way to alleviate this is to make a system that shoots a wall of concentrated air up that is say 5 feet wide, with 3 rotating air cylinders like an autocannon that recharge when not firing to increase the rate of fire.
But this goes back to the limitations of the pneumatics allowed.

[tcjinaz]

Originally Posted by Ninja_Bait

If you can hit a ball with another ball, you should:
a. work for NASA and:
b. use your impressive engineering and programming skills to make a killer offensive robot instead of a defensive one.

First, I yield to <G13> The strategy I proposed will quite likely blow every target out of the Field and into the stands. Safety First.

Onward:
Ah, the reason you don't think I already work for such an outfit is what? (Watch the .sigs)

NASA historically doesn't try to hit other things. Other Agencies (SDI, <litany of US DoD orgs> et al) have tried and succeeded to do so, repeatedly.

Deflection (note, not destruction) of a basketball with another basketball using a control system with a 50mS control loop at ~12ft ranges with known targets from a relatively fixed position near those targets should be easier that dropping the same ball into a basket. Such an automated response during tele-op mode is not unreasonable.

Sure, I start with 2 rounds. I can reload, and if my team sees the value, they'll reload me.

And if I am sitting in the opposition's key, I'm at 84in for the sensor, shooter or both.

Of course, if we get it wrong, we drop balls into the opposition goals. How is that scored?


Now we're having fun