We’ll state right up front that it’s a really, really bad idea to let a robotic archer shoot an apple off of your head. You absolutely should not repeat what you’ll see in the video below, and if you do, the results are all on you.
That said, [Kamal Carter]’s build is pretty darn cool. He wisely chose to use just about the weakest bows you can get, the kind with strings that are basically big, floppy elastic bands that shoot arrows with suction-cup tips and are so harmless that they’re intended for children to play with and you just know they’re going to shoot each other the minute you turn your back no matter what you told them. Target acquisition is the job of an Intel RealSense depth camera, which was used to find targets and calculate the distance to them. An aluminum extrusion frame holds the bow and adjusts its elevation, while a long leadscrew and a servo draw and release the string.
With the running gear sorted, [Kamal] turned to high school physics for calculations such as the spring constant of the bow to determine the arrow’s initial velocity, and the ballistics formula to determine the angle needed to hit the target. And hit it he does — mostly. We’re actually surprised how many on-target shots he got. And yes, he did eventually get it to pull a [William Tell] apple trick — although we couldn’t help but notice from his, ahem, hand posture that he wasn’t exactly filled with self-confidence about where the arrow would end up.
[Kamal] says he drew inspiration both from [Mark Rober]’s dart-catching dartboard and [Shane Wighton]’s self-dunking basketball hoop for this build. We’d say his results put in him good standing with the skill-optional sports community.
For a second there I were thinking he used a real bow. Honestly hard to tell with the Olympic recurve style that toy bow has going for it.
But to a degree. As long as the control loops and recognition software is good. And the assembly is mechanically repeatable. Then with a good bow, the accuracy would be fairly splendid to be fair. And the thing would likely be “safe”.
Though, I would advise strongly against using image recognition software for party tricks like this, unless there is some supervision over the computer’s decisions. But the person getting shot towards can always flinch and arrows are fast, but precision targets like apples, then maybe arrows aren’t always fast enough.
It would though be interesting to see how it fairs on the archery range.
And what about a hardware glitch, the odds are low but it just takes one at the wrong time.
e.g.
o 2003 The extra 4096 votes that happened in Schaerbeek Belgium.
o 2003 Cisco Systems issued a field notice regarding its 1200 series router line cards. The
noticed warned of line card resets resulting from SEUs.
o 2005 St. Jude Medical, Canada issued an advisory to doctors in 2005, warning that SEUs to the
memory of its implantable cardiac defibrillators could cause excessive drain on the unit’s battery.
o 2008 A Quantas Airbus A330-303 pitched downward twice in rapid succession, diving first 650
feet and then 400 feet, seriously injuring a flight attendant and 11 passengers. The cause has
been traced to errors in an on-board computer suspected to have been induced by cosmic rays.
(Modifications were undertaken to mitigate such errors in the future).
( ref: https://en.wikipedia.org/wiki/Single-event_upset and search for “filetype:pdf Microsemi Neutron-Induced Single Event Upset (SEU)” in your search engine of choice)
Yup, hardware and software can have glitches.
Though, so too can humans.
In the end, it is ill advice to point obviously dangerous things towards people.
“In the end, it is ill advice to point obviously dangerous things towards people.”
Depends on your market.
Generally if your business is pouting dangerous things at people, your market are behind you, not in front.
More like machine-vision Archer makes you a real-life Brett Bunsen, am I right?