Conveyance system and conveyance method

1. A conveyance system configured to convey an object by using an autonomous mobile robot, wherein

the autonomous mobile robot comprises:

a placement part;

an arm configured to extend from and retract into the placement part in a horizontal direction, the arm comprising a gear;

a first ball screw disposed parallel to the horizontal direction, the first ball screw comprising a first nut gear, the first nut gear engaged with the gear of the arm; and

a control unit configured to control a movement of the arm,

the control unit moves a tip of the arm into a groove formed in a bottom surface of an object supported from underneath thereof, and then the control unit returns the tip of the arm hooked in the groove to the placement part, or

the control unit moves the tip of the arm hooked in a groove formed in a bottom surface of an object placed on the placement part toward a rack configured to support the object from underneath thereof.

2. The conveyance system according to claim 1 , wherein the arm comprises a shaft part extending in the horizontal direction, and a projection part located at a tip of the shaft part and extending in a direction perpendicular to the shaft part.

3. The conveyance system according to claim 2 , wherein the control unit rotates the projection part by using the shaft part as a rotation shaft.

4. The conveyance system according to claim 3 , further comprising

a second ball screw disposed parallel to the shaft part of the arm and the first ball screw, the second ball screw comprising a second nut gear; and

a slider configured to house the first and second nut gears, and move in a direction in which

the shaft part extends as the first and second nut gears move, wherein the shaft part of the arm comprises the gear,

the gear is engaged with the first and second nut gears inside the slider, and

the control unit controls rotation directions of the first and second ball screws.

5. The conveyance system according to claim 1 , wherein the control unit changes a height of the placement part.

6. The conveyance system according to claim 1 , further comprising a container as the object, wherein

a plurality of grooves arranged in a direction in which the object is moved by the arm is formed in the bottom surface of the object.

7. The conveyance system according to claim 1 , further comprising a container as the object, wherein

the groove in the bottom surface of the object has a V-shape.

8. The conveyance system according to claim 1 , further comprising a container as the object, wherein

the groove in the bottom surface of the object has a circular shape, an elliptical shape, or a rhombus shape.

9. A method for conveying an object by using an autonomous mobile robot, the autonomous mobile robot comprising a placement part and an arm configured to extend from and retract into the placement part in a horizontal direction, the method comprising:

moving a tip of the arm of the autonomous mobile robot to a groove formed in a bottom surface of an object supported from underneath thereof, and then returning the tip of the arm hooked in the groove to the placement part; or

moving the tip of the arm hooked in a groove formed in a bottom surface of an object placed on the placement part toward a rack configured to support the object from underneath thereof,

wherein moving the tip comprises operating a control unit comprising a first ball screw disposed parallel to the horizontal direction, the first ball screw comprising a first nut gear engaged with a gear of the arm.