Could one use a robot vacuum/mop on Shabbos? It is preset and moves around the house while everyone is asleep does its thing then returns to its start point.
A robot vacuum should not be used on Shabbos.
Contemporary poskim give two reasons for this. Firstly it is a denigration to the sanctity of shabbos (zilzul Shabbos) to have electric machines cleaning the floors etc., and because it makes noise (avsha milsa). R’ Moshe Feinstein zt”l originally prohibited using preset Shabbos clocks because if we will permit using Shabbos clocks for anything that we want, it will lead to Shabbos becomeing a regular day since we can technically set a Shabbos cock to even run a factory and the machines will do all the Shabbos work we need. This he said is a zilzul to Shabbos. Although regarding things that are needed the minhjg is to be lenient, such as with air conditioners, there is no need for one to have the carpet swept.