Human-Following Utility Trailer

[Théo Gautier] thought that a human-following utility trailer would be helpful for people working on farms. He didn’t just think about it, however, he designed and built it as a final project at the Agrilab FabAcademy at the University UniLasalle Polytechnique in northern France. He took the idea from concept to fruition in six weeks.

His build log documents the project very well, and takes you through his design choices and their implementation. The brains of the cart are a SAMD21E board that he made himself, and its sensory perception of the world is provided by HC-SR04 ultrasonic sensors and a PixyCam 2. Locomotion is provided by four each 100W DC motor / gearbox assemblies. He’s put a lot of effort into the construction process and posted a lot of photos of the intermediate steps. One piece of advice that caught our eye was to measure the diagonals of your frame repeatedly when welding it together — things can and do shift around. If you don’t, you may have to rectify the mistake like [Théo] did, with a big hammer.

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OpenCV And Depth Camera Spots Weeds

Using vision technology to identify weeds in agriculture is an area of active development, and a team of researchers recently shared their method of using a combination of machine vision plus depth information to identify and map weeds with the help of OpenCV, the open-source computer vision library. Agriculture is how people get fed, and improving weed management is one of its most important challenges.

Many current efforts at weed detection and classification use fancy (and expensive) multispectral cameras, but PhenoCV-WeedCam relies primarily on an OAK-D stereo depth camera. The system is still being developed, but is somewhat further along than a proof of concept. The portable setups use a Raspberry Pi, stereo camera unit, power banks, an Android tablet for interfacing, and currently require an obedient human to move and point them.

It’s an interesting peek at the kind of hands-on work that goes into data gathering for development. Armed with loads of field data from many different environments, the system can use the data to identify grasses, broad leaf plants, and soil in every image. This alone is useful, but depth information also allows the system to estimate overall plant density as well as try to determine the growth center of any particular plant. Knowing that a weed is present is one thing, but to eliminate it with precision — for example with a laser or mini weed whacker on a robot arm — knowing where the weed is actually growing from is an important detail.

PhenoCV-WeedCam (GitHub repository) is not yet capable of real-time analysis, but the results are promising and that’s the next step. The system currently must be carried by people, but could ultimately be attached to a robotic platform made specifically to traverse fields.

Mutant Corn Could Be The Future Of Agriculture

In America, corn syrup is king, and real sugar hovers somewhere around prince status. We’re addicted to corn, and corn, in turn, is addicted to nitrogen. A long time ago, people figured out that by rotating crops, the soil will stay nutrient-rich, which helps to an extent by retaining nitrogen. Then we figured out how to make nitrogen fertilizer, and through its use we essentially doubled the average crop yield over the last hundred years or so.

The aerial roots of the Sierra Mixe corn stalk help the plant produce its own nitrogen. Image via Wikimedia Commons

Not all plants need extra nitrogen. Legumes like beans and soybeans are able to make their own. But corn definitely needs nitrogen. In the 1980s, the now-chief of agriculture for Mars, Inc. Howard-Yana Shapiro went to Mexico, corn capital of the world, looking for new kinds of corn. He found one in southern Mexico, in the Mixes District of Oaxaca. Not only was this corn taller than American corn by several feet, it somehow grew to these dizzying heights in terrible soil.

Shapiro thought the corn’s success might have something to do with the aerial, finger-like roots protruding from the cornstalk. Decades later, it turns out he was right. Researchers at UC Davis have proven that those aerial roots allow the plant to grab nitrogen out of the air through a symbiotic relationship with bacteria in that clear, syrupy mucus. The process is called nitrogen fixation.

Nitrogen Fixing is a Bit Broken

So if we already have nitrogen fertilizer, why even look for plants that do it themselves? The Haber-Bosch fertilizer-making process, which is an artificial form of nitrogen fixation, does make barren soil less of a factor. But that extra nitrogen in ammonia-based fertilizer tends to run off into nearby streams and lakes, making its use an environmental hazard. And the process of creating ammonia for fertilizer involves fossil fuels, uses a lot of energy, and produces greenhouse gases to boot. All in all, it’s a horrible thing to do to the environment for the sake of agriculture. But with so many people to feed, what else is there to do?

The Haber-Bosch process illustrated. Image via Wikimedia Commons

Over the last decade, the UC Davis researchers use DNA sequencing to determine that the mucus on the Sierra Mixe variety of the plant provides microbes to the corn, which give it both sugars to eat and a layer of protection from oxygen. They believe that the plants get 30-80% of their nitrogen this way. The researchers also proved that the microbes do in fact belong to nitrogen-fixing families and are similar to those found in legumes. Most impressively, they were able to transplant Sierra Mixe corn to both Davis, California and Madison, Wisconsin, and have it grow successfully, proving that the nitrogen-fixing trick isn’t limited to the corn’s home turf. Now they are working to identify the genes that produce the aerial roots.

One Step in a Longer Journey of Progress

We probably won’t be switching over to Sierra Mixe corn anytime soon, however. It takes eight months to mature, which is much too slow for American appetites used to a three-month maturation period. If we can figure out how to make other plants do their own nitrogen fixation, who knows how far we could go? It seems likely that more people would accept a superpower grafted from a corn cousin instead of trying to use CRISPR to grant self-nitrogen fixation, as studies have shown a distrust of genetically modified foods.

The issue of intellectual property rights could be a problem, but the researchers started on the right foot with the Mexican government by putting legal agreements in place that ensure the Sierra Mixe community benefits from research and possible commercialization. We can’t wait to see what they’re able to do. If they’re unable to transplant the power of self-fixation to other plants, then perhaps there’s hope for improving the Haber-Bosch process.

Open Agriculture Initiative Shuttered Amid Scandal

The MIT Media Lab’s Open Agriculture Initiative (OpenAg) promised to revolutionize urban farming with their Food Computers: essentially miniature automated gardens that could be installed in racks to maximize growing space. Each unit would be provided with a “Recipe” that allowed it to maintain the ideal environmental conditions for the species it contained, which meant that even the novice gardener to produce a bumper crop no whether they lived in the Arctic Circle or the Sahara.

With such lofty goals, success certainly wasn’t assured. But we still didn’t expect to hear that the program had to be permanently closed after a string of startling accusations came to light. From engaging in scientific dishonesty to setting off a minor ecological disaster, the story just gets worse and worse. Who could have imagined that one day we’d have to report on an open source project having direct ties to Jeffrey Epstein?

Food Computer v3.0

According to reports, MIT Media Lab Director Joichi Ito and OpenAg principal researcher Caleb Harper attempted to secure $1.5 million in funding for the program during a 2017 meeting with the disgraced financier. Epstein apparently wasn’t impressed by what he saw, and no money ever changed hands. Given the information we now have about the project, this might actually be the least surprising part of the story.

It has since come to light that the Food Computers never worked consistently, and indeed never made it past the prototype stage. This despite the fact that Harper claimed that functional units had already been deployed to refugee camps during presentation to potential investors. A scientist working with the project has even come forward with claims that staff were instructed to place plants brought from local garden centers into the prototype Food Computers prior to tours of the lab so visitors would think they had been grown in the devices.

A former researcher working on the OpenAg program, Babak Babakinejad, also went public with his concerns over the environmental impact of dumping waste water from the Food Computers. The lab had a permit to pump nitrogen-infused water into an underground disposal well, but according to Babakinejad, internal testing showed the nitrogen levels in the water would occasionally top 20 times the stated limit. After his concerns were ignored by Harper and other MIT staff, he eventually took his concerns directly to the Massachusetts Department of Environmental Protection which led to an investigation and ultimately a fine of $25K.

We first covered the Open Agriculture Initiative back in 2016, and readers expressed doubts about the concept even then. While we certainly don’t relish making an update like this about a project we’ve featured, it’s an important reminder that honesty and integrity can’t take a backseat to technical achievement.

Hearing Plants Giggle Is Just As Creepy As You Think

While best known for Charlie and the Chocolate Factory, Roald Dahl wrote quite a few similarly oddball stories in his time. One of them, The Sound Machine, is about a device that allowed the user to hear the anguished screams of trees as they were cut down. Sounds kind of weird to us, but [Roni Bandini] liked the idea so much he decided to build his own version.

Now to be fair, the device doesn’t only scream in pain. In fact, most of the time it should be emitting laughs and happy noises. Using a moisture sensor driven into the soil of a plant’s pot, the device uses these audio cues to tell you the relative health of your leafy friend. So assuming you’ve got any sort of green thumb at all, things should be fine.

But once the soil gets too dry and the device determines the plant is in “pain”, things take a turn for the worse. We suppose it doesn’t technically scream out so much as grunt like a zombie, but it’s still not a noise we’d want to hear while walking through the house at night. Luckily, it seems you need to hit the button on the front of the 3D printed enclosure to get it to play the appropriate sound track from its DFPlayer module.

Personally we’d rather build something that makes sure the plants are being taken care of automatically than a gadget that cries out in anguish to remind us that we don’t know what we’re doing. But hey, everyone gets inspired in their own way.

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Modular Solar-Powered IoT Sensors

Bringing a product to market is not easy, if it were everyone would be doing it, and succeeding. The team at Pycno is in the process of launching their second product, a modular solar powered IoT unit called Pulse. It’s always interesting to get an inside look when a company is so open during the development process, and see how they deal with challenges.

Pycno’s first product was a solar powered sensor suite for crops. This time round they are keeping the solar part, but creating a modular system that can accept wired or wireless connections (2G/3G/4G, WiFi, LoRa, GPS and Bluetooth 5) or modules that slide into the bottom of the unit. They plan to open source the module design to allow other to design custom modules, which is a smart move since interoperability can be a big driving factor behind adoption. The ease of plugging in sensors is a very handy feature, since most non-Hackaday users would probably prefer to not open up expensive units to swap out sensors. The custom solar panel itself is pretty interesting, since it features an integrated OLED display. It consists of a PCB with the cutout for the display, with solar cells soldered on before the whole is laminated to protect the cells.

Making a product so completely modular also has some pitfalls, since it can be really tricky to market something able to do anything for anybody. However, we wish them the best of luck with their Kickstarter (video after the break) and look forward to seeing how the ecosystem develops.

When a large community develops around a modular ecosystem, it can truly grow beyond the originator’s wildest dreams. Just look at Arduino and Raspberry Pi. We’re also currently running a contest involving boards for the Feather form factor if you want to get in on the act. Continue reading “Modular Solar-Powered IoT Sensors”

ArrBot Is A Fast Way To Get Out Standing In A New Field Of Robotics

[Junglist] correctly points out that agricultural robotics is fast on its way to being the next big thing (TM) and presents his easy to build ArrBot platform so others can get hacking fast. 

The frame is built out of the same brackets and aluminum tubing used to add handrails to stairwells on buildings. Not only is this a fast way to do it, the set-up can be guaranteed to be sturdy since hand rails are often literally standing between life and death. The high ground clearance allows for all sorts of sensors and devices to be mounted while still being able to clear the plants below. 

For motion hub motors driven by an ODrive were re-purposed for the task. He explored turning the wheels as well, but it seems like  differential steer and casters works well for this set-up. ROS on an Nividia Jetson runs the show and deals with the various sensors such as a stereoscopic camera and IMU.

We’re excited to see what hacks people come up with as research in this area grows. (Tee-hee!) For example, [Junglist] wants to see the effect of simply running a UV light over a field rather than spraying with pesticides or fungicides would have.