1. A self-propelled cleaning machine for cleaning a floor of a room enclosed by a wall perimeter, comprising: a body having first and second sides and a front; a motor drive for causing the body to move over said floor; a cleaning unit carried by the body for cleaning said floor; first, second and third sensors carried by the body for sensing distances from said first and second sides and said front thereof to said wall perimeter and producing first, second and third sensor signals in response thereto respectively; and a fuzzy logic computer for receiving said first, second and third sensor signals and controlling the motor drive to move the body in accordance therewith adjacently parallel to and store data representing said wall perimeter; and subsequently controlling the motor drive to move the body in a computed pattern within said wall perimeter as represented by said data such that the cleaning unit cleans said floor; the computer processing said first or second signal from whichever of the first and second sensors is closer to said wall perimeter using a first number of fuzzy values, and processing the other of said first or second signal and said third signal using a second number of fuzzy values that is smaller than said first number of fuzzy values.