Robot

Abstract

A robot is provided. When a value obtained by excluding a gravitational component from an acceleration detected by an acceleration sensor is continuously less than a reference value for a certain time, a travelling state of the robot is determined as frictional surface travelling. A control circuit calculates an attitude angle of the robot from an angular velocity in a pitch direction, which is detected by an angular velocity sensor. When the calculated attitude angle is a lower limit angle or more for a determination time, the control circuit sets the attitude angle at the end of the determination time as an attitude control angle. When the travelling state of the robot is determined as the frictional surface travelling, the control circuit moves a counterweight frontward by a movement amount corresponding to the attitude control angle.

What is claimed is: 
     
         1 . A robot, comprising:
 a housing;   a frame disposed in the housing;   a display that is provided on the frame, and that displays at least a portion of a face of the robot;   drive wheels that are provided on the frame, and that rotate and move the housing while being in contact with an inner surface of the housing;   a weight drive that is provided on the frame, and that reciprocates a weight in a predetermined direction relative to the weight drive;   an angular velocity sensor that detects angular velocity about a crosswise direction that is perpendicular to a travelling direction of the housing; and   a control circuit that, while the housing is being rotated and moved, when a rotational angle of the housing when viewed from a front of the housing in the travelling direction changes upward beyond a predetermined angle, based on a change in the angular velocity about the crosswise direction, moves the weight frontward in the travelling direction of the housing by a distance corresponding to the rotational angle.   
     
     
         2 . A robot, comprising:
 a housing;   a frame that is disposed in the housing, and that includes a base;   a display that is provided on the frame, and that displays at least a portion of a face of the robot;   drive wheels that are provided on the frame, and that rotate and move the housing while being in contact with an inner surface of the housing;   a weight drive that is provided on the frame, and that reciprocates a weight in a predetermined direction relative to the weight drive;   an acceleration sensor that detects a first acceleration in a vertical direction that is perpendicular to the base;   an angular velocity sensor that detects angular velocity about a crosswise direction that is perpendicular to a travelling direction of the housing; and   a control circuit that acquires a second value by excluding a gravitational component from a first value indicative of the first acceleration detected by the acceleration sensor, wherein   when the control circuit determines, while the housing is being rotated and moved, that the second value changes from a reference value beyond a first change range and to a third value corresponding to a downward direction that is perpendicular to the base, and that a rotational angle of the housing when viewed from a front of the housing in the travelling direction changes upward beyond a predetermined angle, based on a change in the angular velocity about the crosswise direction, the control circuit moves the weight frontward in the travelling direction of the housing by a distance corresponding to the rotational angle.   
     
     
         3 . The robot according to  claim 2 , wherein
 when the control circuit determines, while the housing is being rotated and moved, that the second value changes within the first change range, and that, the rotational angle of the housing when viewed from the front of the housing in the travelling direction changes upward beyond the predetermined angle, based on the change in the angular velocity about the crosswise direction, the control circuit does not move the weight frontward in the travelling direction of the housing.   
     
     
         4 . The robot according to  claim 2 , wherein
 the acceleration sensor detects a second acceleration in the travelling direction of the housing that is parallel to the base, and   while the housing is being rotated and moved, the control circuit moves the weight rearward in the travelling direction of the housing when the second value changes within the first change range, a change in the second acceleration is within a second change range, and a change in the rotational angle of the housing is within the predetermined angle.   
     
     
         5 . The robot according to  claim 2 , wherein
 the acceleration sensor detects a second acceleration in the travelling direction of the housing that is parallel to the base, and   while the housing is being rotated and moved, the control circuit does not move the weight frontward in the travelling direction of the housing when the second value changes within the first change range, a change in the second acceleration is within a second change range, and a change in the rotational angle of the housing is within the predetermined angle.   
     
     
         6 . A robot, comprising:
 a housing;   a frame that is disposed in the housing and that includes a base;   a display that is provided on the frame, and that displays at least a portion of a face of the robot;   drive wheels that are provided on the frame, and that rotate and move the housing while being in contact with an inner surface of the housing;   a weight drive that is provided on the frame, and that reciprocates a weight in a predetermined direction relative to the weight drive;   an acceleration sensor that detects a first acceleration in a vertical direction that is perpendicular to the base;   an angular velocity sensor that detects angular velocity about a crosswise direction that is perpendicular to a travelling direction of the housing; and   a control circuit that acquires a second value by excluding a gravitational component from a first value indicative of the first acceleration detected by the acceleration sensor, wherein   when the control circuit determines, while the housing is being rotated and moved, that the second value changes from a reference value beyond a first change range and to a third value corresponding to a downward direction that is perpendicular to the base, and that the housing when viewed from a front of the housing in the travelling direction rotates from a reference position upward beyond a predetermined angle, based on a change in the angular velocity about the crosswise direction, the control circuit determines a rotational angle of the housing based on the change in the angular velocity about the crosswise direction during a predetermined time after a start of a rotation by the housing from the reference position, and moves the weight from an initial position of the weight frontward in the travelling direction of the housing by a distance corresponding to the rotational angle.   
     
     
         7 . The robot according to  claim 6 , wherein
 when the control circuit determines, based on the change in the angular velocity about the crosswise direction, that the rotation of the housing from the reference position returns to the predetermined angle or less before the predetermined time elapses, the control circuit does not move the weight.   
     
     
         8 . The robot according to  claim 6 , wherein
 while the housing is being rotated and moved, the control circuit does not move the weight when the control circuit determines that the second value changes from the reference value beyond the first change range and to the third value corresponding to the downward direction that is perpendicular to the base, and that an upward rotation of the housing from the reference position when viewed from the front of the housing in the travelling direction is the predetermined angle or less, based on the change in the angular velocity about the crosswise direction.   
     
     
         9 . The robot according to  claim 6 , wherein
 while the housing is being rotated and moved, the control circuit does not move the weight when the control circuit determines that the second value changes within the first change range, and that the housing when viewed from the front of the housing in the travelling direction rotates from the reference position upward beyond the predetermined angle, based on the change in the angular velocity about the crosswise direction.   
     
     
         10 . The robot according to  claim 6 , wherein
 the acceleration sensor detects a second acceleration in the travelling direction of the housing that is parallel to the base, and   while the housing is being rotated and moved, the control circuit moves the weight from an initial position of the weight rearward in the travelling direction of the housing when the control circuit determines that the second value changes within the first change range, that a change in the second acceleration is within a second change range, and that an upward rotation of the housing from the reference position when viewed from the front of the housing in the travelling direction is within the predetermined angle or less, based on the change in the angular velocity about the crosswise direction.   
     
     
         11 . The robot according to  claim 6 , wherein
 the acceleration sensor detects a second acceleration in the travelling direction of the housing that is parallel to the base, and   while the housing is being rotated and moved, the control circuit does perform control to move the weight when the control circuit determines that the second value changes within the first change range, that a change in the second acceleration is within a second change range, and that an upward rotation of the housing from the reference position when viewed from the front of the housing in the travelling direction is within the predetermined angle or less, based on the change in the angular velocity about the crosswise direction.