Cleaning robot guidance system including a cleaning robot and a docking station, and method of controlling the cleaning robot

A system is described comprising a docking station having a first transmission unit to transmit a first docking signal in a first direction, the first docking signal comprising at least a first signal pulse and a second signal pulse, wherein the first signal pulse has a pulse width that has a different time length than a pulse width of the second signal pulse. The system further comprises a robot cleaner comprising a reception unit to receive the first docking signal from the docking station, and a control unit configured to determine if the received first docking signal is an unreflected wave received directly from the first transmission unit or if the received first docking signal is a reflected wave produced by reflection of the first docking signal by an obstacle, the control unit to control movement of the robot cleaner based on whether the received first docking signal is determined to be the reflected wave or the unreflected wave.