95 points by Sabrees 7 hours ago | 10 comments
lorenzohess 1 hour ago
Looks great for a prototype. Has any modeling, simulation, or analysis been done of its off-road performance, i.e. mobility, GO/NOGO, motive efficiency, maneuverability on deformable terrain? This is critical for agricultural applications.

Has any stress analysis been done on the frame? Looks to me like it could use a couple more triangles to reinforce those rectangles.

Have you designed a skid-steering controller for it? Off-road skid steering can be quite variable obviously depending on terrain properties.

Sabrees 28 minutes ago
Rosys (a middleware layer https://github.com/zauberzeug/rosys) has rosys.driving.Odometer and rosys.driving.Steerer it's essentially a differential drive kinematic model.

Hoping RTK dual-F9P moving-base setup (M4 in the roadmap) largely sidesteps the worst of this — NAV-RELPOSNED gives us a real heading vector independent of wheel odometry, and the robot_localisation EKF can weight RTK heavily and odometry lightly when GNSS quality is good.

Sabrees 26 minutes ago
The current simulation is underdeveloped but can be found here https://github.com/samuk/caatingarobotics/tree/jazzy/src/agr...

The frame will almost certainly need more triangles

cpgxiii 2 hours ago
> The hardware is built around a stackable 10×10cm compute module with two ARM Cortex-A55 SBCs — one for ROS 2 navigation/EKF localisation, one dedicated to vision/YOLO inference — connected via a single ethernet cable.

I will preface this by saying that I have nothing against ARM per se, that my employer/team supported a good chunk of the work for making ROS 2 actually work on arm64, and that there is some good hardware out there.

I really don't understand why startups and research projects keep using weird ARM SBCs for their robots. The best of these SBCs is still vastly shittier in terms of software support and stability than any random Chinese Intel ADL-N box. The only reasons to use (weird) ARM SBCs in robots are that either (1) you are using a Jetson for Jetson things (i.e. Nvidia libraries), or (2) you have a product which requires serious cost optimization to be produced at a large scale. Otherwise you are just committing yourselves and your users/customers to a future of terrible-to-nonexistent support and adding significantly to the amount of work you need to bring up the new system and port existing tools to it.

schaefer 2 hours ago
> The only reasons to use ARM SBCs in robots are...

Obviously, anyone can have there own opinion on this. I work in robotics, we are quite happy with our A53 and M4. Though, we use a SOM, not a SBC, if you feel like splitting hairs.

cpgxiii 2 hours ago
You probably aren't using some weird SOM, though. There is a bit of an unstated exception of "unless said SBC/SOM has specific hardware that is necessary/particularly valuable for your product/project". For example, if you need GMSL you are probably not going to be picking Intel, even though ADL-N and the bigger processors support MIPI, simply because no one else does and the documentation/support for it is basically nonexistent. Designs with closely-coupled A/M/R cores, or CPU/MCU/FPGA hybrids like Zynq would be others.

But generally projects which are choosing some random SBC aren't using any of these features, and are just suffering the pain/imposing it on their users for no good reason.

Sabrees 2 hours ago
If you can send me an open hardware Intel, or Jetson I'd happily use it.

Part of the point of this for me is to see what's possible with open hardware (down to chip level at least)

cpgxiii 1 hour ago
There are a variety of x86 products with Coreboot support, if what you are looking for is firmware openness. If what you are looking for is PCB design openness, the options are much fewer, but at that point you are probably optimizing for an overly niche objective.

> Part of the point of this for me is to see what's possible with open hardware (down to chip level at least)

I appreciate the idea, but this is essentially saying "this project will prioritize a specific choice of one (core) piece of hardware to the detriment of everything else, users included". Approximately none of your potential users are going to benefit from the "openness" of the SBC versus that of a more broadly-supported platform (I say "openness" because the reality of SBCs is that actually finding a usefully performant one that is completely blob-free is almost impossible). Open hardware means very little if it isn't running an upstream kernel and userland.

Sabrees 1 hour ago
The software does explicitly support Jetson for example, and I'm sure the stack would run on Intel if you want it to.

The Mainline kernel for this particular board is _almost_ there 6.20 or so I expect. Armbian support is good.

Neywiny 2 hours ago
Framework? Maybe?
Sabrees 1 hour ago
Framweork have done the best they can within the confines of Intel licensing, still a long way from being able to fabricate it though

https://github.com/FrameworkComputer/Framework-Laptop-13/tre...

In a few years we'll all be using more open RISCV stuff of course.

jvanderbot 3 hours ago
What's your payload? Where are the seeds? How are they deposited?

Recommend going to a farm right now to see how this works in production. For the most part, you can autonomously sow using GPS. But the farmer just rides along.

Sabrees 3 hours ago
Payload is whatever you (or your startup) want it to be.

For me personally mechanical between row weeding is step one, then laser in-row weeding.

1. These on some linear actuators: https://www.getearthquake.com/products/fusion-drill-powered-... (they work surprisingly well)

2. Beyond that for in-row weeding a engraving laser on a Delta: https://github.com/Agroecology-Lab/Open-Weeding-Delta/tree/m...

Or if I'm feeling rich by then this third party weeder looks pretty good https://github.com/Laudando-Associates-LLC/LASER

3. For Seeding my salad crop https://reagtools.co.uk/collections/jang

4. Harvesting my salad crop https://reagtools.co.uk/products/quick-cut-greens-harvester

I live on a farm, I have sold salad commercially, these are largely tools I already use and own, just moved about by motors rather than muscles.

This is a smaller scale thing than arable. We're talking a step up from manual horticulture (which is actually what still feeds much of the world)

sgillen 3 hours ago
Very cool! shameless self promotion but check out greenwave-monitor[1] for the 'Diagnostics TUI'. I'll get it into the buildfarm soon.

[1] https://github.com/NVIDIA-ISAAC-ROS/greenwave_monitor

Sabrees 3 hours ago
Nice, thanks! looks like a good one..
agentifysh 1 hour ago
outside of sowing would you consider some open source drones like the new DJI with agriculture payload attached to it.

or some automated green house with open source designs.

love the name sowbot.

Sabrees 1 hour ago
I did recently automate a greenhouse (heating, Hydroponics, fans, lights) it was just R&D rather than commercial so just used home assistant for it.

I did sketch out a slightly more 'professionalised' version, but haven't built it yet https://github.com/samuk/IoT-Greenhouse-Temperature-and-Irri...

I'd be pleasantly surprised if DJI had done anything open source, Ardupilot is pretty capable of course. I really want to automate the time consuming labour parts of horticulture, for me that's mostly weeding and to a lesser extent harvesting.

dylan604 5 hours ago
From a video somewhere in the page: "The aim is to make food production more sustainable and efficient" yet requires a web app. I'd hope that you can run the server side on a local machine and not require cloud connectivity.
Sabrees 4 hours ago
The web app runs locally from the robot. No cloud. Once we reach autonomy (still some way away) you shouldn't have to use that much either.
Sabrees 4 hours ago
Quite interested in running robot<>robot and robot<>Farm comms over https://reticulum.network/ but that's a side project off a side project..
dheera 4 hours ago
I highly encourage you to go visit farms sooner rather than later, especially during the rainy seasons and winter when farmers are really at work preparing for the next season. The kind of conditions robots need to deal with in that environment is no joke.

I also notice you're using the BNO055 -- if you need an C++ I2C ROS driver for it I wrote one (https://github.com/dheera/ros-imu-bno055). I think the one in the ROS apt-get repository is written in Python but they claimed the package name before I did

Sabrees 4 hours ago
Good advice on farms. I do live on a farm, so somewhat familiar with mud! Many of the worst problems are caused by moving 20ton tractors around IMHO, one of the problems small scale ag robotics may help with.

Will check out your Bno055 currently using the upstream one in Lizard

https://github.com/zauberzeug/lizard/blob/main/main/modules/... https://github.com/zauberzeug/lizard/blob/main/main/modules/...

Any review of that welcome too of course.

MoonWalk 5 hours ago
Great name, if nothing else!
Sabrees 5 hours ago
Thanks, bit conflicted about it TBH, it's primarily/initially a weeding robot, although I do dream of expanding it to do harvesting, and yes potentially sowing too down the line.

Strapping something like the Jang P6 to it is probably feasible https://reagtools.co.uk/collections/jang

For the harvester it would be a bolt on for https://reagtools.co.uk/products/quick-cut-greens-harvester or maybe https://reagtools.co.uk/products/babyleaf-harvester-80cm (I grow green salads)

tda 4 hours ago
And for weeding?
Sabrees 4 hours ago
Initially keep it simple; Mechanical for between row weeding. I'll probably start strapping a couple of these to some linear actuators: https://www.getearthquake.com/products/fusion-drill-powered-... (they work surprisingly well)

Beyond that for in-row weeding a engraving laser on a Delta: https://github.com/Agroecology-Lab/Open-Weeding-Delta/tree/m...

Or if I'm feeling rich by then this third party weeder looks pretty good https://github.com/Laudando-Associates-LLC/LASER

tda 4 hours ago
I sometimes help out at a hobby vineyard of 0.7 hectare; weeding in the row is a lot of manual labour. Your platform seems like a good fit. I like tinkering and robotics, what kind of price point are you aiming for?
falkenstein 2 hours ago
a simple ride on mower with a diy inter row disc (basically just a belt and pulley with a spring) may be enough. probably just get sonebody with a tractor and inter row disc weeder to do the job for you.
Sabrees 4 hours ago
As cheap as possible, and no cheaper than that.

In my head it's £3-£5k, so by the time it's useful probably a bit more than that.

TGower 2 hours ago
What's the plan for using an engraving laser in open air without blinding a neighbor? Does the bot fully roll over the target area before firing or something?
Sabrees 2 hours ago
TBC, just trying to get the platform and mechanical weeding working for now
rrr_oh_man 4 hours ago
A joke that's whooshing over my head?
Sabrees 4 hours ago
A robot that Sows seeds..
rrr_oh_man 3 hours ago
Aaaaaargh.

(╯°□°)╯︵ ┻━┻

Thank you.

abraae 4 hours ago
This is the future, good luck to you
pixelsub 3 hours ago
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