Article storage facility

1. An article storage facility comprising:

an article storage rack including a plurality of storage sections arranged in a vertical direction and a lateral direction, each of the storage sections including a storage support body that supports an article from below;

a movement support body that supports the article;

a movement mechanism that moves the movement support body in the vertical direction and the lateral direction in a movement space provided along a front of the article storage rack, and moves the movement support body along a front-rear direction that is a direction of arrangement of the movement space and the article storage rack; and

a control portion that controls the movement mechanism;

wherein:

the control portion is configured to cause the movement mechanism to execute a movement operation of moving the movement support body to a target stop position that is set so as to correspond to each of the plurality of storage sections and stopping the movement support body at the target stop position, and a transfer operation of lowering the movement support body at the target stop position and delivering the article to the storage support body,

the movement support body is configured such that an imaging device can be removably attached thereto,

the imaging device is configured to, in a state in which the movement support body is at the target stop position, be controlled by the control portion so as to image from above an imaging target location that is set in the storage support body of the storage section corresponding to said target stop position, and

the control portion is configured to execute:

a preliminary movement process of causing the movement mechanism to execute a preliminary movement operation of moving the movement support body with the imaging device attached thereto to a preliminary target stop position that is preset as the target stop position and stopping the movement support body at the preliminary target stop position;

an imaging process of causing the imaging device to image the imaging target location in a state in which the movement support body is stopped at the preliminary target stop position;

an offset amount calculation process of calculating, based on a captured image obtained by the imaging process, a positional offset amount of the movement support body in the front-rear direction and the lateral direction from a proper position of the movement support body that is a position at which the article supported by the movement support body can be delivered to a proper storage position of the storage support body by the transfer operation; and

a correction process of correcting the preliminary target stop position based on the positional offset amount calculated by the offset amount calculation process and setting the target stop position.

2. The article storage facility according to claim 1 , wherein the movement support body includes a detection device that detects that a position in the vertical direction and a position in the lateral direction of the movement support body relative to the storage support body are at a proper front position that permits movement of the movement support body along the front-rear direction, and

wherein the control portion is configured to:

as the preliminary movement process, execute a first movement process of moving the movement support body in the vertical direction and the lateral direction and thereafter execute a second movement process of moving said movement support body in the front-rear direction; and, after execution of the first movement process and before execution of the second movement process, execute a second movement execution determination process of determining whether the second movement process is executable based on detection information from the detection device mounted to the movement support body, and

the control portion starts execution of the second movement process if it is determined in the second movement execution determination process that the second movement process is executable, and does not start execution of the second movement process if it is determined that the second movement process is not executable.

3. The article storage facility according to claim 1 , wherein:

the storage support body includes a plurality of positioning members for positioning the article at the proper storage position,

the plurality of positioning members are disposed so as to be distributed in plan view,

the imaging device is configured to image the imaging target location by using a location in which a target positioning member included in the plurality of positioning members is provided as the imaging target location, and

the control portion executes the offset amount calculation process based on an actual position of the target positioning member in the captured image, and a position of the target positioning member in the captured image that has been imaged with the imaging device when the movement support body is located at the proper position.

4. The article storage facility according to claim 1 , wherein:

the movement support body includes a vertical distance measurement portion that measures a vertical distance that is a distance in the vertical direction between the movement support body located at the target stop position and the storage support body, and

the control portion is configured to execute a height offset amount calculation process of calculating a height offset amount that is a difference between a proper distance that is a distance in the vertical direction between the movement support body located at the proper position and the storage support body and the vertical distance measured with the vertical distance measurement portion in a state in which the movement support body is located at the preliminary target stop position by the preliminary movement operation, and an abnormality determination process of determining whether the height offset amount calculated by the height offset amount calculation process is in an abnormal height state that is greater than an allowable amount.

5. The article storage facility according to claim 4 , wherein the control portion is configured to, if it is determined in the abnormality determination process that the height offset amount is not in the abnormal height state, execute a height correction process of correcting the preliminary target stop position based on the height offset amount and setting the target stop position.