PURPOSE: A movable robot system for mowing the grass and a method for controlling the same are provided to stop the operation of a mowing device when infrared rays are not detected by the detecting device, thereby preventing the operation of the mowing device outside a grass existing area. CONSTITUTION: A movable robot system(1) for mowing the grass comprises a body, a boundary indicating device(20), a detecting device(150), a mowing device(140), and a control unit(160). A moving device(120) is comprised in the body. The boundary indicating device includes an infrared ray irradiating unit(210). A grass existing area is marked by using infrared rays irradiated from the infrared ray irradiating unit. The detecting device is comprised in the body, thereby detecting the infrared rays. The control unit stops the operation of the mowing device when the infrared rays are not detected by the detecting device in moving. [Reference numerals] (10) Movable robot for mowing the grass； (120) Moving device； (130) Power supply device； (140) Mowing device； (150) Detecting device； (151) Infrared sensor； (160) Control unit； (161) Memory； (20) Boundary indicating device； (210) Infrared ray irradiating unit； (220) Lamp unit； (230) Photovoltaic cell본 발명의 일 실시예에 따른 잔디 깎기용 이동로봇 시스템은 이동장치가 구비된 본체와, 적외선을 조사하는 적외선 조사부가 구비되어 적외선 조사부에서 조사되는 적외선으로 잔디존재영역을 표시하는 경계표시장치와, 본체에 구비되어 상기 적외선을 감지하는 감지장치와, 본체에 구비되어 잔디를 절삭하는 절삭장치 및, 이동장치에 의해 이동 중 적외선이 감지장치에서 감지되지 않으면 절삭장치의 구동을 정지시키는 제어부를 포함한다.
