Motion sensors detect moving heat sources, although the motor in the vacuum cleaner would be generating heat it should be fairly well shielded by the casing and very little of that heat would actually be visible to the sensor.
My guess would be no it wouldn't set the sensors off.
I think its the speed as well
it used to be the case that they were PIRs (passive ir) so they don't need or use heat (as such) to detect - it's a matrix of detectors
the movement of a detectable object between adjacent cells sets it off - so if you strike a match but hold it so it doesn't trigger two cells ... it won't go off
a cold object moving over a warmer background is the same as a warm one moving over a cold one.
many many minutes ago -- we used to have races across opposite ends of a room .... the winner was the one who didn't set off the detector .... sloooooow and steady.
so to answer your question (possibly - it's only a guess really) it might.
you could always try a radio controlled car first .... more fun
Stewey, you're so funny... you wouldn't turn the alarm on if you were home pushing a vacuum cleaner!
I'm not sure of the answer Blackhorn, because alarm systems are different.
How about you turn on your Roomba and your alarm and sit outside for a little while and see? Better than guessing and having the alarm activated all day annoying the neighbours who may not take any notice of it next time it goes off for a ligitimate reason.
Ok......I feel a little stupid now. I really didn't realize that you were talking about one of those 'robots' that do your cleaning when you're not home and hence the alarm is on. Oh well; learn something every day!
They always look really slow to me. Buy a nice Vax. brilliant suction, all the tools, does the job in a jiffy - and mine came with a 10 year guarantee!
Thanks for your answers Folks. Roomba's seem to sell very well so someone must have thought of this before now. Good idea with the toy car, I've just borrowed a radio-controlled Dalek as a test!
As for the speed of the thing, IceMaiden, I'm out all day
(usually) so it can take all day......if it does a decent job I'll be happy to leave 'him' to it.