That's what made sense for my company; we just identify the crop, and then churn up all the areas of dirt that are "not crop". Also, hey, free cultivation. Do it often enough, and your weeds never even get that large, which also greatly increases your identification accuracy.
I had a professor in college who was building self-driving tractors and would come in every other week complaining about John Deere this, or Case that, trying to steal his business with more expensive solutions. It turns out you can use GPS for a rough location and a fancy $200 gyroscope for millimeter precision. Then just plant the seeds on an exact grid and you know that anything not on the grid is a weed.
And actually, his suggestion was to use high-pressure water jets to cut the weeds instead of lasers. It would/could be less energy-intensive.
RTK GPS is used as a second factor to vision in these machines. It’s just not good enough to target with as a sole / primary factor in the real world though. Bit of drift and whoops, $30,000 of crop gone.
Lasers are not used because they’re expensive and dangerous. And Co2 lasers (as per the machine in the article) are powerful but super fragile.
Water shooting around at high pressure is in no way efficient or easy to handle.
Thanks for posting this, very interesting. The linkedin profile pointed to a youtube video (unlisted) that was pretty interesting and covered how they could calculate eye safely using simple math that indicated the safe distance was 2 meters away. They appeared to be using blue LEDs at high intensity to char-or-inactivate weed photosynthesis.