Disclosed herein are a lawn mower robot and a method of controlling the same. The method includes receiving a signal generated by a boundary wire, determining a maximum value and a minimum value of the received signal for a predetermined time, and determining a position of a main body, which receives the signal, relative to the boundary wire by identifying and comparing the number of upper inflection portions present within a constant maximum value range and the number of lower inflection portions present within a constant minimum value range for the predetermined time, wherein each of the upper inflection portions means a portion at which a waveform of the signal is changed from ascending to descending and each of the lower inflection portions means a portion at which a waveform of the signal is changed from descending to ascending.
