A robot cleaner, comprising: a body; a cleaning device operably coupled in the body and configured to draw dust from a cleaning region into the body; an optical pattern sensor provided on a front surface of the body and configured to irradiate an optical pattern and generate a corresponding pattern image; and a controller configured to recognize an obstacle based on the pattern image generated by the optical pattern sensor, wherein the controller comprises an obstacle recognition module configured to process the pattern image to recognize the obstacle; characterized in that the optical pattern sensor comprises: an optical source module configured to irradiate one or more cross-shaped optical patterns outward from a front side of the body; and a camera module configured to capture the pattern image of the region irradiated by the one or more optical patterns, wherein the optical pattern sensor is configured to irradiate an asymmetric cross-shaped optical pattern having a horizontal pattern and a vertical pattern, a length of the horizontal pattern being greater than a length of the vertical pattern, wherein the obstacle recognition module recognizes a width of the obstacle using the horizontal pattern of the pattern image and a height of the obstacle using the vertical pattern of the pattern image. a body; a cleaning device operably coupled in the body and configured to draw dust from a cleaning region into the body; an optical pattern sensor provided on a front surface of the body and configured to irradiate an optical pattern and generate a corresponding pattern image; and a controller configured to recognize an obstacle based on the pattern image generated by the optical pattern sensor, wherein the controller comprises an obstacle recognition module configured to process the pattern image to recognize the obstacle; characterized in that the optical pattern sensor comprises: an optical source module configured to irradiate one or more cross-shaped optical patterns outward from a front side of the body; and a camera module configured to capture the pattern image of the region irradiated by the one or more optical patterns, wherein the optical pattern sensor is configured to irradiate an asymmetric cross-shaped optical pattern having a horizontal pattern and a vertical pattern, a length of the horizontal pattern being greater than a length of the vertical pattern, wherein the obstacle recognition module recognizes a width of the obstacle using the horizontal pattern of the pattern image and a height of the obstacle using the vertical pattern of the pattern image. an optical source module configured to irradiate one or more cross-shaped optical patterns outward from a front side of the body; and a camera module configured to capture the pattern image of the region irradiated by the one or more optical patterns, wherein the optical pattern sensor is configured to irradiate an asymmetric cross-shaped optical pattern having a horizontal pattern and a vertical pattern, a length of the horizontal pattern being greater than a length of the vertical pattern, wherein the obstacle recognition module recognizes a width of the obstacle using the horizontal pattern of the pattern image and a height of the obstacle using the vertical pattern of the pattern image.