Robot device and operating method thereof for delivering object to target table

A robot device for delivering an object to a target table having a rectangular shape, the robot device comprising:

• a sub-body with rollers configured to move the robot device;
• a body coupled to an upper end of the sub-body with rollers and configured to rotate independently of the sub-body with rollers about a rotation axis, the body comprising:
• a tray configured to accommodate the object and comprising a plurality of side surfaces;
• and
• a tray support configured to support the tray being located at a certain height;
• a memory configured to store at least one instruction;
• and
• at least one processor configured to execute the at least one instruction,
• wherein the plurality of side surfaces comprise a first side surface that is covered by the tray support and a second side surface that is not covered by the tray support,
• wherein the at least one processor is further configured to execute the at least one instruction to:
• receive an external input including information about the target table,
• control, based on the information about the target table, the sub-body with rollers to move to the target table by:
• turning, in response to the sub-body with rollers being located at a distance greater than a first certain distance from the target table, the body such that a direction perpendicular to the first side surface is parallel to a movement direction of the sub-body with rollers, and
• turning, in response to the sub-body with rollers being located at the first certain distance or at a distance smaller than the first certain distance from the target table, the body such that a direction perpendicular to the first side surface and the movement direction of the sub-body with rollers are different, and
• stopping rotation of the body in response to the second side surface being parallel to a side surface that is closest to the robot device among a plurality of side surfaces of the target table,
• wherein the first certain distance is a distance at which the body starts to rotate independently of the sub-body with rollers, the first certain distance being obtained based on at least one of information about the target table, a movement path of the robot device, or a rotation speed of the body.