Wouldn't a few HD cameras on the ceiling and OpenCV be as effective at 10x less cost without getting in everyone's way?
Another way is to measure surface specularity. Use one or more IR spotlights at different angles to the surface and strobe them on and off. A wet surface will have a different angular variation in reflectivity vs a dry surface, unless the floor is very shiny.
1. https://thinklucid.com/tech-briefs/polarization-explained-so...
So how many robots are needed per store if they're to have more effective coverage than asking the employees who roam the aisles tidying and re-stocking shelves, helping customers find things, fulfilling click-and-collect orders, etc., to also report spills?
Or perhaps these stores don't have any such employees on the floor -- they're just an array of unserviced aisles, with some staff at the checkouts?
Still substantial but less than without it.
Most of the restocking and cleaning happens when the store is closed. Customers don't want to have people getting in their way stocking shelves and you don't want to be mopping floors (other than cleaning up spills) when customers are walking down them.
Thats a lot of cameras you could buy right there. I was figuring around 100 for a medium sized store. (40 ft isles, 12 of them, 2 cameras every 10 feet). How much is a little wifi camera that can send back a few images per minute?
I was discussing cameras with someone who derives a non-negligible portion of their income from streaming 4k video. The "gold standard" as far as they are concerned is a $60 Logitech webcam. Swap out the cord for a wifi chip, swap out the consumer housing for something that clips to a shelf and can be secured with a self tapping screw and power it with a cheap solar panel and I still can't see it coming in above $100.