Robot

A robot comprising:

• a first spherical cap portion;
• a second spherical cap portion;
• a spherical band-shaped main casing disposed between the first spherical cap portion and the second spherical cap portion, the main casing having a first flat surface to interface a flat surface of the first spherical cap portion, and a second flat surface to interface a flat surface of the second spherical cap portion;
• a first shaft that joins the first spherical cap portion to the second spherical cap portion;
• a display that is attached to the shaft via an arm and that displays at least part of a face of the robot in a forward direction;
• a weight that is provided inside of the main casing and that rotates around a second shaft of the weight that is disposed perpendicular to the first shaft;
• a first drive mechanism drives a rotation of the shaft to rotate the first spherical cap portion and the second spherical cap portion;
• a second drive mechanism independent from the first drive mechanism, the second drive mechanism drives a rotation of the main casing about the shaft to cause a linear movement of the robot, the linear movement including a movement in the forward direction and a movement in a rear direction;
• a weight drive mechanism that rotates the second shaft;
• a range finding sensor disposed in one of the first spherical cap portion and the second spherical cap portion to face in a same direction as the display;
• a gyro sensor that measures a turning angle of the robot about an axis perpendicular to a plane including the shaft and detects a shaking movement of the robot;
• a camera that captures an image of an environment surrounding the robot;
• a microphone that acquires a sound signal emanating from the environment surrounding the robot;
• a memory;
• and
• a control circuit,
• wherein, if the control circuit determines that an image of a person is included in the image captured by the camera or voice of the person is included in the sound signal acquired by the microphone, the control circuit performs following operation a predetermined number of times:
• controlling the second drive mechanism to stop the rotation of the main casing,
• controlling the weight drive mechanism to tilt the weight to a first side that is in a direction towards one of the first spherical cap or the second spherical cap,
• controlling the second drive mechanism to start a rotation of the main casing to move the main casing forward with the weight tilted to the first side,
• controlling the second drive mechanism to stop the rotation of the main casing,
• tilting the weight to a second side different from the first side, and
• controlling the second drive mechanism to start a rotation of the main casing to move the main casing backward with the weight tilted to the second side, so that the robot is turned to a predetermined turning angle corresponding to a direction in which the person is positioned,
• wherein the control circuit subsequently controls the first drive mechanism to rotate the range finding sensor around the shaft in at least one of an upward direction and a downward direction in increments of a predetermined angle,
• wherein the range finding sensor measures a distance from the range finding sensor to an object facing the display each time the range finding sensor rotates through the predetermined angle,
• wherein, if a difference between a first distance between the range finding sensor and the object previously measured and a second distance between the range finding sensor and the object subsequently measured is greater than or equal to a predetermined value, the control circuit determines that a down-step is located in a direction defined by the turning angle of the robot when the first distance is measured at a position the first distance away from the range finding sensor, and
• wherein the control circuit subsequently rotates the main casing and moves the main casing forward by a distance that is smaller than the first distance.