Robot cleaner system having a sub-robot for corner cleaning

PURPOSE: A robot cleaner system is provided to smoothly clean a narrow space as well as a wide space by employing of docking station for a small sub robot in a main cleaning robot. CONSTITUTION: A robot cleaner system comprises a first cleaning robot(100) and a second cleaning robot. The first cleaning robot comprises a first suction unit, a first dust collecting unit, a first dust intake, and a first dust vent and draws in dust from the floor by moving around a wide area through an automatic travel function. The first cleaning robot also has a docking station able to mount the second cleaning robot. The second cleaning robot comprises a second suction unit, a second dust collecting unit, a second dust intake, and a second vent and draws in dust from corners by moving around a narrow area. The second cleaning robot is mounted on or demounted from the docking station under the control of the first cleaning robot.