First and foremost, you should follow the directions in your instruction manual for where to place the robot vacuum. While most will offer similar guidance, the measurements required can vary, and some designs may prefer a greater clearance. Generally speaking though, your robot vacuum should be placed against a flat and straight wall on a level surface, with around 3 ft of clearance on each side, and at least 4 ft in front. This is so that it has adequate space to start cleaning and dock on re-entry, without any furniture getting in the way. Don’t forget that it needs access to a power socket as well.
If you’re using a standard charging base, you may have to fix it to the wall, so the robot vacuum won’t knock it out of place. Some bases come with stickers to help with this issue. If you’re lucky enough to own a robot vacuum with a self-emptying base, it should be heavy enough to hold itself in place. Although this does mean it will likely require more clearance space and will protrude further out from the wall as well. Make sure you have a space in mind for your robot vacuum’s dock before you make a purchase, otherwise you might have to move some furniture around.