Robot cleaner and method of controlling traveling thereof

Abstract

Disclosed herein are a robot cleaner that has an improved traveling performance, and a method of controlling traveling thereof. The robot cleaner allows driving wheels, which move the robot cleaner, and a brush unit, which sweeps dust on a floor, to be rotated in the same direction.

1 . A robot cleaner, comprising:
 a main body;   a plurality of driving wheels to move the main body;   a brush unit rotated to sweep dust on a floor; and   a control unit to control the brush unit to be rotated in a same direction as rotation of the driving wheels, when the main body travels backward.   
     
     
         2 . The robot cleaner according to  claim 1 , further comprising:
 a brush motor to rotate the brush unit in a forward or reverse direction; and   a plurality of driving motors to rotate the driving wheels in the forward or reverse direction,   wherein the control unit controls the driving wheels and the brush unit to be rotated in the same direction.   
     
     
         3 . The robot cleaner according to  claim 2 , wherein the control unit controls forward and backward traveling of the main body by changing the rotating direction of the brush unit according to change of the rotating direction of the driving wheels. 
     
     
         4 . The robot cleaner according to  claim 3 , wherein the control unit controls the brush motor such that the brush motor is rotated at a relatively high speed in an initial stage when the rotating direction of the brush unit starts to be changed, and the rotating speed of the brush motor is reduced when the rotating direction of the brush unit has been changed. 
     
     
         5 . A robot cleaner comprising:
 a main body;   a plurality of driving wheels to move the main body;   a brush unit rotated to sweep dust on a floor; and   a control unit to control the brush unit to be rotated in a same direction as rotation of the driving wheels according to a state of the floor, when the main body travels backward.   
     
     
         6 . The robot cleaner according to  claim 5 , further comprising a floor surface sensor to sense the state of the floor, the state of the floor including a resistance, wherein the control unit controls the brush unit to be rotated in the same direction as the driving wheels, if the floor has a high resistance. 
     
     
         7 . The robot cleaner according to  claim 5 , further comprising a plurality of driving sensors to sense movement of the driving wheels, wherein the control unit controls the brush unit to be rotated in the same direction as the driving wheels, if no movement of the driving wheels is sensed by the driving sensors. 
     
     
         8 . The robot cleaner according to  claim 5 , further comprising driving motors to rotate the driving wheels in a forward or reverse direction, and a load sensor to sense a load applied to the driving motors, wherein the control unit controls the brush unit to be rotated in the same direction as the driving wheels, if the sensed load is greater than a reference value. 
     
     
         9 . A method of controlling traveling of a robot cleaner, the method comprising:
 detecting a rotating direction of driving wheels that move the robot cleaner;   determining a rotating direction of a brush unit according to the rotating direction of the driving wheels; and   moving the robot cleaner forward or backward comprising rotating the driving wheels and the brush unit in the same direction according to the determined rotating direction of the brush unit.   
     
     
         10 . The method according to  claim 9 , wherein the determining the rotating direction of the brush unit comprises changing the rotating direction of the brush unit into a direction to allow the robot cleaner to smoothly travel forward when the driving wheels are rotated in the forward direction. 
     
     
         11 . The method according to  claim 9 , wherein the determining of the rotating direction of the brush unit comprises changing the rotating direction of the brush unit into a direction to allow the robot cleaner to smoothly travel backward when the driving wheels are rotated in the backward direction. 
     
     
         12 . The method according to  claim 9 , further comprising sensing a resistance of a floor, wherein, the determining of the rotating direction of the brush unit comprises changing the rotating direction of the brush unit into the same direction as the rotating direction of the driving wheels, if the floor has a high resistance. 
     
     
         13 . The method according to  claim 9 , further comprising sensing movement of the driving wheels, wherein, the determining of the rotating direction of the brush unit comprises changing the rotating direction of the brush unit to the same direction as the rotating direction of the driving wheels, if no movement of the driving wheels is sensed. 
     
     
         14 . The method according to  claim 9 , further comprising sensing a load applied to the driving wheels, wherein, the determining of the rotating direction of the brush unit comprises changing the rotating direction of the brush unit into the same direction as the rotating direction of the driving wheels, if the load is greater than a reference value. 
     
     
         15 . The method according to  claim 9 , further comprising controlling the brush unit such that the brush unit is rotated at a relatively high speed in an initial stage when the rotating direction of the brush unit starts to be changed, and reducing the rotating speed of the brush motor when the rotating direction of the brush unit has been changed.