A robot system and a control method thereof in which, when a robot is located in a docking region, the robot calculates a distance by emitting infrared rays and detecting ultrasonic waves oscillated from a charging station, measures a distance from the charging station and performs docking with charging station. The distance between the robot and the charging station is precisely measured, thereby performing smooth and correct docking of the robot with the charging station. Further, the robot emits infrared rays only while performing docking with the charging station and thus reduces power consumption required for infrared ray emission, and wakes up a circuit in the charging station based on the infrared rays emitted from the robot and thus reduces power consumption of the charging station.