Sandia’s self-guided bullet prototype

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Minuteman
May 1, 2009
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Original article with videos and pictures here: Sandia Bullet

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body"> ALBUQUERQUE, N.M — Take two Sandia National Laboratories engineers who are hunters, get them talking about the sport and it shouldn’t be surprising when the conversation leads to a patented design for a self-guided bullet that could help war fighters. (Click here for a video showing the prototype’s flight.)

Sandia researchers Red Jones and Brian Kast and their colleagues have invented a dart-like, self-guided bullet for small-caliber, smooth-bore firearms that could hit laser-designated targets at distances of more than a mile (about 2,000 meters).

“We have a very promising technology to guide small projectiles that could be fully developed inexpensively and rapidly,” Jones said.

Sandia is seeking a private company partner to complete testing of the prototype and bring a guided bullet to the marketplace.

Researchers have had initial success testing the design in computer simulations and in field tests of prototypes, built from commercially available parts, Jones said.

While engineering issues remain, “we’re confident in our science base and we’re confident the engineering-technology base is there to solve the problems,” he said.

Sandia’s design for the four-inch-long bullet includes an optical sensor in the nose to detect a laser beam on a target. The sensor sends information to guidance and control electronics that use an algorithm in an eight-bit central processing unit to command electromagnetic actuators. These actuators steer tiny fins that guide the bullet to the target.

Most bullets shot from rifles, which have grooves, or rifling, that cause them to spin so they fly straight, like a long football pass. To enable a bullet to turn in flight toward a target and to simplify the design, the spin had to go, Jones said.

The bullet flies straight due to its aerodynamically stable design, which consists of a center of gravity that sits forward in the projectile and tiny fins that enable it to fly without spin, just as a dart does, he said.

Computer aerodynamic modeling shows the design would result in dramatic improvements in accuracy, Jones said. Computer simulations showed an unguided bullet under real-world conditions could miss a target more than a half mile away (1,000 meters away) by 9.8 yards (9 meters), but a guided bullet would get within 8 inches (0.2 meters), according to the patent.

Plastic sabots provide a gas seal in the cartridge and protect the delicate fins until they drop off after the bullet emerges from the firearm’s barrel.

The prototype does not require a device found in guided missiles called an inertial measuring unit, which would have added substantially to its cost. Instead, the researchers found that the bullet’s relatively small size when compared to guided missiles “is helping us all around. It’s kind of a fortuitous thing that none of us saw when we started,” Jones said.

As the bullet flies through the air, it pitches and yaws at a set rate based on its mass and size. In larger guided missiles, the rate of flight-path corrections is relatively slow, so each correction needs to be very precise because fewer corrections are possible during flight. But “the natural body frequency of this bullet is about 30 hertz, so we can make corrections 30 times per second. That means we can overcorrect, so we don’t have to be as precise each time,” Jones said.

Testing has shown the electromagnetic actuator performs well and the bullet can reach speeds of 2,400 feet per second, or Mach 2.1, using commercially available gunpowder. The researchers are confident it could reach standard military speeds using customized gunpowder.

And a nighttime field test, in which a tiny light-emitting diode, or LED, was attached to the bullet showed the battery and electronics can survive flight, Jones said.

Researchers also filmed high-speed video of the bullet radically pitching as it exited the barrel. The bullet pitches less as it flies down range, a phenomenon known to long-range firearms experts as “going to sleep.” Because the bullet’s motions settle the longer it is in flight, accuracy improves at longer ranges, Jones said.

“Nobody had ever seen that, but we’ve got high-speed video photography that shows that it’s true,” he said.

Potential customers for the bullet include the military, law enforcement and recreational shooters.
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Re: Sandia’s self-guided bullet prototype

cool technology, but basically just trading problems; good wind calls for the ability to hold a laser on target for a couple seconds. assuming you don't have a teammate running the laser, you'll need to come back on target pretty fast after surviving the recoil of launching a 4" projo at 2400.


i'm actually a lot more interested in seeing the high-speed footage of the bullet going to sleep
 
Re: Sandia’s self-guided bullet prototype

My question is what laser is being used? With standard explosive munitions the "painted" area can be relatively large, but if you're going for a center of mass target at 2000yds won't the laser spot be too large to be effective?

I'm imagining a 20" circle to be the designated area at 2000yds so my understanding is the bullet can hit anywhere on that circle. Sure you'll be likely to at least clip a person with that ability, but can't trained snipers make a more reliable shot with ULR calibers like the 375CT?


It is pretty kick-ass though.
 
Re: Sandia’s self-guided bullet prototype

This is interesting, but as someone above pointed out, it would require the spotter to lase the target.

As to a conventional sniper being more accurate... doubtful. On a KD range where the landscape is the same every time you go to shoot there, and you've done it often, it's much easier to make those environmental calls such as wind and what not. It's a good bit more difficult in the field where you've never shot in this location; anyone that tells you they can reliably hit a man-sized target at 2km with a rifle is questionable at best. If that were the case, a 2.4km kill wouldn't be holding the records right now. Figure if you can reliably hit at 2k, 2.5k should bring you periodical hits.

Think about it- 8" group at 2km... that is a tall order for even the best.
 
Re: Sandia’s self-guided bullet prototype

I'd love to see the footage they made of the bullets pitching in flight...sounds like it could be quite interesting to see what's actually going on.
 
Re: Sandia’s self-guided bullet prototype

8" at 2000 meters... that would be hitting .34 moa or less, if I'm looking at the numbers right. That is pretty impressive, especially if it is consistent.
 
Re: Sandia’s self-guided bullet prototype

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Autark</div><div class="ubbcode-body">8" at 2000 meters... that would be hitting .34 moa or less, if I'm looking at the numbers right. That is pretty impressive, especially if it is consistent. </div></div>

But it's so much harder than .34moa sounds... Wind calls being one of the most difficult at that range, along with environment...