What are you using to find the position an movement of your robot?
Encoders fail when slip occurs, GPS is wildly innacurate and INS requires a fair bit of processing power plus accurate and hence expensive sensors
So I put it to you what do most people use as a solutions
Encoders to start. Then a acceleration sensor to help determine when slip happens. All this backed by sonic and IR sensors. I have not done a room mapper in years. When i did i used a Motorola MC68HC11 as the mcu.
Since then I guess i would choose to use roborealm/camera as my base sensor. With some sure calculation distance sensors or you can go for the gusto and get a laser range finder.
When pondering about mobile robot navigation I tend to think that worrying about being ‘exact’ is a waste of time. I’m not very exact when navigating but I make loads of course calculations that are sort of accurate and the resulting average is pretty good. So rather then worrying about the in-exactness of each sensor I would tend to concentrate on the fusion of all the data from the various sensors and how they can be used collaboratively.