Robot, robot control method, and recording medium

Abstract

Disclosed is a robot including: a base part; a movable part attached to the base part in a rotatable state around a predetermined rotation axis; an actuator to rotate the movable part around the rotation axis; and one or more processors that control an orientation of the movable part around the rotation axis by controlling operation of the actuator. The processors determine whether the orientation of movable part is within a predetermined angle range including a predetermined reference orientation, in response to determining that the orientation is within the predetermined angle range, the processors control the actuator to be in a first state in which the actuator does not restrict rotation of the movable part, and in response to determining that the orientation is not within the predetermined angle range, the processors control the actuator to be in a second state in which the actuator restricts the rotation.

1 . A robot comprising:
 a base part;   a movable part attached to the base part in a rotatable state around a predetermined rotation axis;   an actuator to rotate the movable part around the rotation axis; and   one or more processors that control an orientation of the movable part around the rotation axis by controlling an operation of the actuator, wherein   the one or more processors determine whether the orientation of the movable part is within a predetermined angle range including a predetermined reference orientation,   in response to determining that the orientation is within the predetermined angle range, the one or more processors control the actuator to be in a first state in which the actuator does not restrict rotation of the movable part, and   in response to determining that the orientation is not within the predetermined angle range, the one or more processors control the actuator to be in a second state in which the actuator restricts rotation of the movable part.   
     
     
         2 . The robot according to  claim 1 , wherein
 the actuator is a servo motor capable of rotating the movable part in an indicated orientation and performing angle control to maintain the orientation,   the first state is a state in which the servo motor does not perform the angle control, and   the second state is a state in which the servo motor performs the angle control.   
     
     
         3 . The robot according to  claim 2 , wherein
 in response to the determining that the orientation is within the predetermined angle range, the one or more processors control the servo motor to be in the first state by stopping power supply to the servo motor.   
     
     
         4 . The robot according to  claim 1 , wherein
 the one or more processors rotate the movable part around the rotation axis by the actuator so that a posture of the movable part is maintained when a posture of the base part has changed, and   the one or more processors determine whether the orientation of the movable part is within the predetermined angle range when a change in the posture of the base part has stopped.   
     
     
         5 . The robot according to  claim 1 , further comprising
 an exterior covering the base part and the movable part, wherein   the predetermined angle range is set within a range of the orientation of the movable part such that the movable part is not moved by a force received from the exterior when the actuator is in the first state.   
     
     
         6 . The robot according to  claim 1 , wherein
 the base part is a torso of the robot, and   the movable part is a head of the robot.   
     
     
         7 . The robot according to  claim 1 , wherein
 the rotation axis includes a first rotation axis and a second rotation axis,   the actuator includes:   a first actuator to rotate the movable part around the first rotation axis; and   a second actuator to rotate the movable part around the second rotation axis that intersects the first rotation axis,   the orientation includes a first orientation and a second orientation,   the predetermined angle range includes a predetermined first angle range including a first reference orientation and a predetermined second angle range including a second reference orientation,   when the one or more processors stop rotation of the movable part around the first rotation axis,   the one or more processors determine whether the first orientation of the movable part around the first rotation axis is within the first angle range,   in response to determining that the first orientation is within the first angle range, the one or more processors control the first actuator to be in the first state,   in response to determining that the first orientation is not within the first angle range, the one or more processors control the first actuator to be in the second state, and   when the one or more processors stop rotation of the movable part around the second rotation axis,   the one or more processors determine whether the second orientation of the movable part around the second rotation axis is within the second angle range,   in response to determining that the second orientation is within the second angle range, the one or more processors control the second actuator to be in the first state, and   in response to determining that the second orientation is not within the second angle range, the one or more processors control the second actuator to be in the second state.   
     
     
         8 . A robot control method for a robot including: a base part; a movable part attached to the base part in a rotatable state around a predetermined rotation axis; and an actuator to rotate the movable part around the rotation axis, the method comprising:
 controlling an orientation of the movable part around the rotation axis by controlling an operation of the actuator;   when stopping rotation of the movable part, determining whether the orientation of the movable part is within a predetermined angle range including a predetermined reference orientation;   in response to determining that the orientation is within the predetermined angle range, controlling the actuator to be in a first state in which the actuator does not restrict rotation of the movable part; and   in response to determining that the orientation is not within the predetermined angle range, controlling the actuator to be in a second state in which the actuator restricts rotation of the movable part.   
     
     
         9 . A computer-readable non-transitory recording medium recording thereon a program for a computer provided in a robot including: a base part; a movable part attached to the base part in a rotatable state around a predetermined rotation axis; and an actuator to rotate the movable part around the rotation axis, the program causing the computer to function as
 a processor that controls an orientation of the movable part around the rotation axis by controlling an operation of the actuator, wherein   when the processor stops rotation of the movable part, the processor determines whether the orientation of the movable part is within a predetermined angle range including a predetermined reference orientation,   in response to determining that the orientation is within the predetermined angle range, the processor controls the actuator to be in a first state in which the actuator does not restrict rotation of the movable part, and   in response to determining that the orientation is not within the predetermined angle range, the processor controls the actuator to be in a second state in which the actuator restricts rotation of the movable part.