A weed killing laser robot seems obviously stupid - an expensive electro-mechanical system generating trivial value with each weed zapped. There is no way to get the price down low enough for this to make sense. But CD players have servo control of the tracking and focus of the laser. Much lower power than needed for weed wacking, but much faster and more accurate than needed and very cheap. https://www.youtube.com/watch?v=wplLkxBsqQo Adequate cameras are cheap enough. AI vision processing is on a roll and we can look forward to huge price falls. The technology looks promising from the outside.