Man Buys Two Metric Tons of LEGO Bricks; Sorts Them Via Machine Learning

iStock // Ekaterina Minaeva
iStock // Ekaterina Minaeva

Jacques Mattheij made a small, but awesome, mistake. He went on eBay one evening and bid on a bunch of bulk LEGO brick auctions, then went to sleep. Upon waking, he discovered that he was the high bidder on many, and was now the proud owner of two tons of LEGO bricks. (This is about 4400 pounds.) He wrote, "[L]esson 1: if you win almost all bids you are bidding too high."

Mattheij had noticed that bulk, unsorted bricks sell for something like €10/kilogram, whereas sets are roughly €40/kg and rare parts go for up to €100/kg. Much of the value of the bricks is in their sorting. If he could reduce the entropy of these bins of unsorted bricks, he could make a tidy profit. While many people do this work by hand, the problem is enormous—just the kind of challenge for a computer. Mattheij writes:

There are 38000+ shapes and there are 100+ possible shades of color (you can roughly tell how old someone is by asking them what lego colors they remember from their youth).

In the following months, Mattheij built a proof-of-concept sorting system using, of course, LEGO. He broke the problem down into a series of sub-problems (including "feeding LEGO reliably from a hopper is surprisingly hard," one of those facts of nature that will stymie even the best system design). After tinkering with the prototype at length, he expanded the system to a surprisingly complex system of conveyer belts (powered by a home treadmill), various pieces of cabinetry, and "copious quantities of crazy glue."

Here's a video showing the current system running at low speed:

The key part of the system was running the bricks past a camera paired with a computer running a neural net-based image classifier. That allows the computer (when sufficiently trained on brick images) to recognize bricks and thus categorize them by color, shape, or other parameters. Remember that as bricks pass by, they can be in any orientation, can be dirty, can even be stuck to other pieces. So having a flexible software system is key to recognizing—in a fraction of a second—what a given brick is, in order to sort it out. When a match is found, a jet of compressed air pops the piece off the conveyer belt and into a waiting bin.

After much experimentation, Mattheij rewrote the software (several times in fact) to accomplish a variety of basic tasks. At its core, the system takes images from a webcam and feeds them to a neural network to do the classification. Of course, the neural net needs to be "trained" by showing it lots of images, and telling it what those images represent. Mattheij's breakthrough was allowing the machine to effectively train itself, with guidance: Running pieces through allows the system to take its own photos, make a guess, and build on that guess. As long as Mattheij corrects the incorrect guesses, he ends up with a decent (and self-reinforcing) corpus of training data. As the machine continues running, it can rack up more training, allowing it to recognize a broad variety of pieces on the fly.

Here's another video, focusing on how the pieces move on conveyer belts (running at slow speed so puny humans can follow). You can also see the air jets in action:

In an email interview, Mattheij told Mental Floss that the system currently sorts LEGO bricks into more than 50 categories. It can also be run in a color-sorting mode to bin the parts across 12 color groups. (Thus at present you'd likely do a two-pass sort on the bricks: once for shape, then a separate pass for color.) He continues to refine the system, with a focus on making its recognition abilities faster. At some point down the line, he plans to make the software portion open source. You're on your own as far as building conveyer belts, bins, and so forth.

Check out Mattheij's writeup in two parts for more information. It starts with an overview of the story, followed up with a deep dive on the software. He's also tweeting about the project (among other things). And if you look around a bit, you'll find bulk LEGO brick auctions online—it's definitely a thing!

The UK Wants to Use 'Noise Cameras' to Crack Down on Loud Cars and Bikes

iStock/Ales-A
iStock/Ales-A

Snarled traffic creates more than air pollution. Thanks to modified engines, mufflers, and exhaust systems on cars and motorcycles, congested roadways can become symphonies of belching and rattling. Now, the UK government is looking to do something about it.

According to the BBC, the Department for Transport is currently testing “acoustic cameras” that will measure the decibel levels of vehicles on public roads. If a microphone detects a vehicle producing an excessive amount of noise, a camera will photograph the source and the owner will be fined.

What defines excessive? That remains to be seen. The UK enacted a law in 2016 limiting new cars to no more than 74 decibels. It's primarily older cars and modified motorbikes that create noise disturbances and prompt complaints from people living nearby.

The trial equipment will also need to prove it can identify one vehicle's noise emissions from another's and single out cars from other possible sources of sound. If the trial results are promising, it's likely the "acoustic cameras" will be policing UK roads in the near future.

[h/t Jalopnik]

This Scented Smart Candle is Fire-Safe and Alexa-Friendly

LuDela
LuDela

Candlelight can do a lot for a room, setting a mood and signaling that it’s time to relax. But not everyone is comfortable with the idea of nursing a tiny flame and melting wax indoors. Technology has provided a solution in the form of the LuDela Perfect Pillar, a smart candle and decorative accent that takes the worry out of a flame-lit atmosphere.

The battery-powered artificial candle generates its flame with refillable liquid paraffin and offers a variety of different scents in the form of SunScent fragrance rings, which you can place on top of the candle to release the scent of your choice. The candle never dims or melts, and you can swap out its fragrance ring at any time to give your home a new scent.

The LuDela Perfect Pillar smart candle starter set
LuDela

The LuDela candle's smart features make it a safer choice than your typical accent candle, especially for homes with small kids or pets. For instance, it has a sensor inside that detects when the device is tilting; if it falls over, the flame is automatically extinguished. You can also turn the candle on and off or create a timed session using the included remote control or your Amazon Alexa. The remote control comes with a child-lock option to prevent little hands from turning the candle on without adult supervision.

You can find the LuDela Perfect Pillar on Amazon, where a starter set with a wax candle fixture, two liquid paraffin refills (which burn for approximately 20 hours each), two fragrance rings, and a remote control goes for $99. Subsequent refill capsules cost $10 per two-pack.

Mental Floss has affiliate relationships with certain retailers and may receive a small percentage of any sale. But we choose all products independently and only get commission on items you buy and don't return, so we're only happy if you're happy. Thanks for helping us pay the bills!

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