When we run an article with “DOOM” in the title, it’s typically another example of getting the venerable game running on some minimalist platform. This DOOM-based VR rig for rats, though, is less about hacking DOOM, and more about hacking the rats.
What started as a side project for [Viktor Tóth] has evolved into quite a complex apparatus. At the center of the rig is an omnidirectional treadmill comprised of a polystyrene ball about the size of a bowling ball. The ball is free to rotate, with sensors detecting rotation in two axes — it’s basically a big electromechanical mouse upside down. The rat rides at the top of the ball, wearing a harness to keep it from slipping off. A large curved monitor sits right in front of the rat to display the virtual environment, which is a custom DOOM map.
With the VR rig built, [Viktor] worked on automating the training. A treat dispenser provides the proper motivation, while powered drive wheels engage with the ball to nudge the rat if it gets stuck in the virtual world. [Viktor] says he has trained three rats — [Romero], [Carmack], and [Tom] — to walk down a straight hallway using this automated method. As for the meat of the game — shooting monsters — [Viktor] has that covered too, with a sensor that detects when a rat rears up on its hind legs to register a shot.
Total training time to get the rats to the point seen in the video was about six weeks, and [Viktor] reports the whole thing cost him about $2000. That’s a lot of time and money, but the results are pretty interesting. If you’re more interested in minimalist DOOM builds, we understand — check out DOOM on a lightbulb, or a thermostat, or even a GPS.
In theory, it’s fun to have a lot of toys tools around, but the sad reality is that it’s only as fun as the organization level applied. Take it from someone who finds organization itself thrilling: it really doesn’t matter how many bits and bobs you have, as long as there’s a place for everything and you put away your toys at the end of the day.
But [Cranktown City] did much more than that. The system is housed in a really nice DIY stand that supports his new milling and drilling machine and has space to hold a certain type of ubiquitous red tool box beneath the drill bits drawer.
All the bits now sit in a 3D-printed index that fits the width of the drawer. [Cranktown City] tried to use daisy-chained pairs of screws as contacts behind each bit that could tell whether the bit was home or not, but too much resistance interfered with the signal. He ended up using a tiny limit switch behind each bit instead. If any bit is removed, the input signal from the index goes low, and this triggers the Arduino Nano to do two things: it lights up a strip of red LEDs behind the beautiful cut out letters on the drawer’s lip, and it starts counting upward. Every ten minutes that one or more bits are missing, the drawer complains and issues ad hominem attacks. Check out the demo and build video after the break, but not until you put your tools away. (Have you learned nothing?)
We didn’t realize that dog training research techniques were so high-tech. Operant conditioning, as opposed to Pavlovian, gives a positive reward, in this case dog treats, to reinforce a desired behavior. Traditionally operant conditioning involved dispensing the treat manually and some devices do exist using wireless remote controls, but they are still manually operated and can give inconsistent results (too many or too few treats). There weren’t any existing methods available to automate this process, so this team decided to rectify the situation.
They took a commercial treat dispenser and retro-fitted it with an interface board that taps into the dispenser’s IR sensors to detect that the hopper is moving and treats were actually dispensed. The interface board connects to a Raspberry Pi which serves as a full-featured platform to run the tests. In this demonstration it connects to an HDMI monitor, detecting touches from the dog’s nose to correlate with events onscreen. Future researchers won’t have to reinvent the wheel, just redesign the test itself, because [Walker] and [Jeffrey] have released all the firmware and hardware as open-source on the lab’s GitHub repository.
In the short video clip below, watch the dog as he gets a treat when he taps the white dot with his snout. If you look closely, at one point the dog briefly moves the mouse pointer as well. We predict by next year the C-CHIL researchers will have this fellow drawing pictures and playing checkers.
Despite epithets like “bird-brain,” our feathered friends are actually pretty smart. Being able to maneuver in three dimensions at high speed must have something to do with it, and the cognitive abilities of birds are well-documented and still being researched. So it naturally makes sense to harness avian brainpower to keep one’s yard clean, right?
For the record, the magpies that [Hans] is training are very intelligent and strikingly beautiful birds who delight in swooping down to harass people, and who will gladly steal food from other birds and then poop on it and fly away. So they’re jerks, but that doesn’t mean they can’t be useful jerks. The goal with his BirdBox system is to use classic operant conditioning, where a desired voluntary behavior is reinforced by a reward. In this case, the reward is a treat dispensed by a 3D-printed vibratory dispenser when the bird collects a bottlecap from the yard and deposits it in the proper slot. The video below shows the birds doing exactly what they’re supposed to do.
[Hans] tells us that the trick is getting the birds to accept the BirdBox and to have them integrate it into their “patrol schematic” of their territory. Once that’s done, it’s a simpler matter to have them associate the bottlecaps with the reward. The other challenge is making everything bulletproof, or in this case magpie-proof. Did we mention that magpies are jerks?
The possibilities for trading peanuts for yardwork are endless; [Hans] mentions plans he has for fallen fruit clean-up, and mentions a persistent garden slug problem that the birds might be employed to remediate. If you want to try this, it might be a good idea to brush up on the work of [B.F. Skinner] and his pigeons of war.
Well this is unusual. Behold the Magic Flute of Rat Mind Control, and as a project it is all about altering the response to the instrument, rather than being about hacking the musical instrument itself. It’s [Kurt White]’s entry to the Musical Instrument Challenge portion of The Hackaday Prize, and it’s as intriguing as it is different.
[Kurt] has created a portable, internet-connected, automated food dispenser with a live streaming video feed and the ability to play recorded sounds. That device (named Nicodemus) is used as a Skinner Box to train rats — anywhere rats may be found — using operant conditioning to make them expect food when they hear a few bars of Black Sabbath’s Iron Man played on a small recorder (which is a type of flute.)
In short, the flute would allow one to summon hordes of rats as if by magic, because they have been trained by Nicodemus to associate Iron Man with food.
Many of the system’s elements are informed by the results of research into sound preference in rats, as well as their ability to discriminate between different melodies, so long as the right frequencies are present. The summoning part is all about science, but what about how to protect oneself from the hordes of hungry rodents who arrive with sharp teeth and high expectations of being fed? According to [Kurt], that’s where the magic comes in. He seems very certain that a ritual to convert a wooden recorder into a magic flute is all the protection one would need.
Embedded below is something I’m comfortable calling the strangest use case video we’ve ever seen. Well, we think it’s a dramatized use case. Perhaps it’s more correctly a mood piece or motivational assist. Outsider Art? You decide.
The image of the crackpot inventor, disheveled, disorganized, and surrounded by the remains of his failures, is an enduring Hollywood trope. While a simple look around one’s shop will probably reveal how such stereotypes get started, the image is largely not a fair characterization of the creative mind and how it works, and does not properly respect those who struggle daily to push the state of the art into uncharted territory.
That said, there are plenty of wacky ideas that have come down the pike, most of which mercifully fade away before attracting undue attention. In times of war, though, the need for new and better ways to blow each other up tends to bring out the really nutty ideas and lower the barrier to revealing them publically, or at least to military officials.
Of all the zany plans that came from the fertile minds on each side of World War II, few seem as out there as a plan to use birds to pilot bombs to their targets. And yet such a plan was not only actively developed, it came from the fertile mind of one of the 20th century’s most brilliant psychologists, and very nearly resulted in a fieldable weapon that would let fly the birds of war.
There’s a harsh truth underlying all robotic research: compared to evolution, we suck at making things move. Nature has a couple billion years of practice making things that can slide, hop, fly, swim and run, so why not leverage those platforms? That’s the idea behind this turtle with a navigation robot strapped to its back.
This reminds us somewhat of an alternative universe sci-fi story by S.M. Stirling called The Sky People. In the story, Venus is teeming with dinosaurs that Terran colonists use as beasts of burden with brain implants that stimulate pleasure centers to control them. While the team led by [Phill Seung-Lee] at the Korean Advanced Institute of Science and Technology isn’t likely to get as much work from the red-eared slider turtle as the colonists in the story got from their bionic dinosaurs, there’s still plenty to learn from a setup like this. Using what amounts to a head-up display for the turtle in the form of a strip of LEDs, along with a food dispenser for positive reinforcement, the bionic terrapin is trained to associate food with the flashing LEDs. The LEDs are then used as cues as the turtle navigates between waypoints in a tank. Sadly, the full article is behind a paywall, but the video below gives you a taste of the gripping action.