Here’s an image of a bullet’s path to the target. There’s a couple of things to note. First of all, this is not a tracer round, the projectile actually has an LED incorporated which was picked up as a trail in the long (relative to bullet speed) exposure. The second – and most obvious – thing to consider is the non-liner path it took to its objective. That’s because this is a laser guided bullet.
The smart bullet is a about four inches long and carries with it a light sensor, 8-bit processor, and some electromagnetic actuators. The tip is searching for a laser-painted target, with an algorithm calculating course corrections along the way and using the actuators to move fins which alter its path. For us the most interesting part is that this ammo requires a non-rifled barrel. The rifling spins the bullet as it leaves the firearm, which usually results in a straighter and more dependable path. But the microcontroller wouldn’t be able reliably steer if it were spinning.
We’d bet this ends up as a special sniper tool in video games before we hear about it on the battlefield. Check out a clip of the dart-like bullet leaving the muzzle in the clip after the break.
Continue reading “Last century’s guided missile steps aside for this guided bullet”
Did you know that a standard camera flash is much too slow to capture high quality images of bullets? A relatively long flash duration results in blurred images of the bullet. By building this air gap flash a bullet can be frozen in mid-air, producing some stunning results. There is an element of danger here, and not from the bullet. This flash uses a 35,000 volt capacitor to produce the mini-bolt of lightning which serves as the light source. The unit can be built for a few hundred dollars, which sounds like a heck of a deal if commercial models really do start at $8k and go up from there.
Now that the photographer has a super-fast flash, a camera axe takes care of the timing… which is everything.
[Mike] built a sensor rig to measure projectile speed. The setup uses a tunnel with two sensors in it. Each consists of a laser diode on one side focused on a photodiode in the other. The two are monitored by an op amp and measured by an ATmega128 microcontroller. When the beams are broken the elapsed time between the two events is measured in order to calculate speed. There is a setting to adjust the calibration for a range of speeds, which came in quite handy as [Mike] initially tested the device with rubber bands before moving on to a pellet gun and then a rifle.
It seems like he’s tempting fate by shooting a target just a few inches below his exposed circuitry but his marksmanship prevailed. We’ve seen bullet speed detectors in the past, used just for the delight of seeing how fast the projectile is moving, and also to capture an impact at just the right instant.
Sometimes it’s amazing how slow our sense of time is. We find [Maurice's] bullet capture system a great example of this. A pair of IR sensors spaced two inches apart can capture and calculate the speed of a projectile. Couple this with a user-input distance from the sensor to the target and a microcontroller can extrapolate the exact moment to trigger a camera to catch a bullet in mid-air.
As with his other projects, all the details on how to build and use this system are available for your perusal.
This is not a hack. In fact it’s a promotional montage for a collection of scientific equipment that few of us could likely afford. But like yesterday’s giant marionettes over Berlin, sometimes even a costly and delicately-orchestrated achievement transcends its own not-a-hack-ness, fulfilling our brains’ lust for wonderment all the same.
Kurzzeit of Germany produces ballistics measurement equipment. The video depicts various combinations of projectiles and targets at up to one million frames per second, revealing unexpected beauty in hitherto unseen phenomena, and is the best damn ten minutes you will waste on the internet all day!