A vacuum cleaner and method for determining the kind of floor surface being cleaned by a vacuum cleaner wherein dust amount per unit interval is detected and dust detection change patterns are analyzed for determining floor type. This analysis is based on the following assumptions: smooth and carpet...http://www.google.com/patents/US5144715?utm_source=gb-gplus-sharePatent US5144715 - Vacuum cleaner and method of determining type of floor surface being cleaned thereby
