My alarm clock broke, so I was early at work today. As I dawdled past the recently reseeded front lawn I noticed people pulling tufts up. Apparently some unwanted plants had gotten in and they were in doing a morning stint getting rid of them before the sun got too hot.
This is just the job for a robot. The ZWR will patrol the area, looking at each blade of grass and leaf through a multispectral sensor. If the readings do not match a set of templates (for young, mature & senile leaves) it deploys a parbolic mirror or a convex lens, focusing the sun's rays to kill that weed. It will be powered by solar panels. No batteries. It cannot work when the sun is behind a cloud anyway.
For StarChaser, a bolt-on attachment has two arms, one having a comb and the other, clippers. Periodically the length of the grass is tested and the excess cut back to leave an interesting pattern, programmed by buried bar magnets.-- neelandan, Feb 16 2002 Uses lasers, but nearly the same thing. https://interesting...0000-weeds-per-hourA machine to kill weeds using CO2 lasers after identifying them with cameras. [neelandan, Apr 29 2021] Alas, you must kill the root.-- phoenix, Feb 16 2002 Oh yes, back-from-the-ashes bird. Heating an area of soil does kill the roots within.-- neelandan, Feb 16 2002 isn't the broad leaf weedkiller cheaper, I was hoping this was something that cut the grass. croissant anyway for thought, spelling and well just because....-- po, Feb 16 2002 No reason it oculdn't cut grass too. Large fresnel lenses are cheap and can melt asphalt on a good sunny day...-- StarChaser, Feb 16 2002 If you have a robot you don't need to kill the root - just trim the leaf. I don't care if I have weed roots if I can't see or smell them. Eventually the roots will die from lack of sunlight anyway.-- tolly3, Feb 17 2002 not a gardener, obviously, tolly3.-- po, Feb 17 2002 SC: Cutting grass would need to be done using shears. A bolt-on attachment added, at your request.-- neelandan, Feb 18 2002 [-] Weeds are just plants, but in what you have determined to be the wrong place. Often they're important for biodiversity, insects, pollination, etc.-- hippo, Apr 29 2021 OK so the Buttercups & Daisies look pretty in an otherwise pristine lawn, they can stay, the rest are toast.-- Skewed, Apr 29 2021 Ah, energetics rule. It is a less energetically intensive for the brain to look at a flat useless mono-cultured area than than a highly bio diverse, complex pattern. There may be dangers there.
Then again I suppose we all want to make a mark of some sort in existence of our own presence. Gardening is just one where nature tries to fight back.-- wjt, May 01 2021 random, halfbakery