Vacuum cleaner and control method thereof

A self-driving cleaner comprising:

• a main body traveling through a cleaning area and sucking foreign substances from a floor in the cleaning area;
• a drive unit for moving the main body in the cleaning area;
• a pattern irradiation unit, disposed on a front surface of the main body, for irradiating light in a predetermined pattern toward a lower front side of the main body;
• a camera, disposed on a front surface of the main body, for photographing the front of the main body;
• and
• a controller for detecting a light pattern formed by the pattern irradiation unit using an image photographed by the camera, determining whether an obstacle exists in front of the main body on the basis of brightness of the detected light pattern, and controlling the drive unit to pass or avoid the obstacle on the basis of a result of the determination,
• wherein the controller controls the drive unit to reduce a moving speed of the main body when the brightness of the detected light pattern is less than or equal to a preset reference brightness, and
• wherein the controller variably sets the reference brightness based on an angle formed between a line segment formed by the light pattern and a reference line set in the image.