Moving robot and controlling method thereof

Abstract

A moving robot includes a traveling unit, a power supply unit, a communication unit, and a memory to store therein coordinates information regarding a point to which the main body has moved by a reference distance in a state of being in contact with the charging station, and a control unit to output a control command to return to the charging station based on a state of the power supply unit while the main body travels in the one area, to determine a position of the charging station from a current position of the main body based on a first signal transmitted from the charging station and a second signal transmitted by the communication unit, in response to the output of the control command, and to controls the traveling unit so that the main body moves to a position corresponding to the stored coordinates information.

What is claimed is: 
     
         1 . A moving robot that travels within one area where a charging station is installed, the moving robot comprising:
 a traveling unit to rotate or move a main body;   a power supply unit to supply power to the main body;   a communication unit to transmit and receive signals to and from the charging station;   a memory to store therein coordinates information regarding a point to which the main body has moved by a reference distance in a state of being in contact with the charging station; and   a control unit to output a control command to return to the charging station based on a state of the power supply unit while the main body travels in the one area,   wherein the control unit determines a position of the charging station from a current position of the main body based on a first signal transmitted from the charging station and a second signal transmitted by the communication unit, in response to the output of the control command, and controls the traveling unit so that the main body moves to a position corresponding to the stored coordinates information, and   wherein the control unit calculates a rotation angle for docking to the charging station based on the first signal and the second signal when the main body reaches the position corresponding to the stored coordinates information, and controls the traveling unit so that a head of the main body is rotated according to the calculated rotation angle.   
     
     
         2 . The moving robot of  claim 1 , wherein the charging station is provided with a pair of Ultra-wideband (UWB) modules to transmit the first signal and receive the second signal, and
 wherein the communication unit of the main body is provided with a pair of UWB modules to receive the first signal and transmit the second signal.   
     
     
         3 . The moving robot of  claim 2 , wherein the pair of UWB modules provided in the communication unit is disposed to be symmetric in right and left directions with respect to the front of the main body, and determines the position of the charging station with respect to the current position of the main body by receiving the first signal from the charging station, respectively. 
     
     
         4 . The moving robot of  claim 3 , wherein the control unit, while the main body moves to the position corresponding to the stored coordinates information, determines one intersection close to a head direction of the main body as the position of the charging station, of two intersections between a first circle that a distance between a first UWB anchor provided in the communication unit and a first UWB tag of the charging station is a radius and the first UWB anchor is a center, and a second circle that a distance between a second UWB anchor provided in the communication unit and a second UWB tag of the charging station is a radius and the second UWB anchor is a center. 
     
     
         5 . The moving robot of  claim 1 , wherein coordinates information of a point to which the main body has moved backward by a reference distance in a state of being in contact with the charging station includes angle information calculated based on the first signal and the second signal. 
     
     
         6 . The moving robot of  claim 1 , wherein the control unit calculates distance information and angle information between the current position of the main body and the charging station based on the first signal received from the charging station and the second signal transmitted by the communication unit, in response to the output of the control command, and controls the traveling unit so that the head of the main body is rotated toward the position corresponding to the stored coordinates information. 
     
     
         7 . The moving robot of  claim 6 , wherein the control unit checks the position of the charging station in real time based on the first signal received through a plurality of UWB modules while the main body moves to the position corresponding to the stored coordinates information after the head of the main body is rotated toward the point corresponding to the stored coordinates information. 
     
     
         8 . The moving robot of  claim 7 , wherein the control unit, after the main body moves to the position corresponding to the stored coordinates information, determines a head direction of the main body on the basis of the angle information calculated based on the first signal received from the charging station and the second signal transmitted by the communication unit, and then controls the traveling unit so that the head is rotated according to the determined head direction. 
     
     
         9 . The moving robot of  claim 8 , wherein the control unit, after the head is rotated according to the determined head direction, checks whether or not to correct the determined head direction, based on a difference between distances at which the first signal transmitted from the charging station is received by a first UWB module and a second UWB module disposed in the main body, respectively. 
     
     
         10 . The moving robot of  claim 9 , wherein a current head direction is determined as a docking direction when it is determined that the distance at which the first signal is received by the first UWB module is the same as the distance at which the first signal is received by the second UWB module. 
     
     
         11 . The moving robot of  claim 1 , wherein the control unit controls the traveling unit so that the main body docks to the charging station by moving straightly by the reference distance, after the main body rotates the head according to the calculated rotation angle at the position corresponding to the stored coordinates information. 
     
     
         12 . The moving robot of  claim 1 , wherein the control unit determines the position of the charging station in real time based on the first signal and the second signal while the main body moves to the position corresponding to the stored coordinates information, and
 sets a docking path by avoiding the charging station when the position of the charging station is included in a path along which the main body moves to the stored coordinates information.   
     
     
         13 . The moving robot of  claim 1 , wherein the control unit stores position information regarding the main body at a time point when the control command has been output, and controls the traveling unit so that the main body moves to the stored position information when the main body docks to the charging station and charging of the power supply unit is completed. 
     
     
         14 . A method for controlling a moving robot that travels within one area where a charging station is installed, the method comprising:
 storing in advance coordinates information regarding a point, to which a main body of the moving robot has moved by a reference distance in a state of being in contact with the charging station;   outputting a control command to return to the charging station based on a state of a power supply unit that supplies power to the main body while the main body travels in the one area;   determining a position of the charging station with respect to the main body based on a first signal transmitted from the charging station and a second signal transmitted by the main body, in response to the output of the control command, and controlling the main body to move to a position corresponding to the stored coordinates information; and   calculating a rotation angle for docking to the charging station based on the first signal and the second signal when the main body reaches the position corresponding to the stored coordinates information, and controlling a head of the main body to be rotated according to the calculated rotation angle.   
     
     
         15 . The method of  claim 14 , wherein the controlling the main body to move to the position corresponding to the stored coordinates information comprises:
 calculating distance information and angle information between a current position of the main body and the charging station based on the first signal received from the charging station and the second signal transmitted by the main body, in response to the output of the control command; and   controlling the head of the main body to be rotated toward the position corresponding to the stored coordinates information.   
     
     
         16 . The method of  claim 15 , further comprising:
 checking the position of the charging station in real time based on the first signal received through a plurality of UWB modules provided in the main body while the main body moves to the position corresponding to the stored coordinates information after the head of the main body is rotated toward the position corresponding to the stored coordinates information.   
     
     
         17 . The method of  claim 16 , further comprising, after the main body moves to the position corresponding to the stored coordinates information:
 determining a head direction of the main body on the basis of the angle information calculated based on the first signal received from the charging station and the second signal transmitted by the main body; and   rotating the head according to the determined head direction and docking to the charging station.