Article storage facility and method of operating same

1. An article storage facility comprising:

an article storage rack including a plurality of levels of support shelves that are spaced apart from one another in a vertical direction, each support shelf being capable of storing a plurality of articles arranged in a row in a horizontal direction;

travel paths with a travel path provided for each level of the support shelves and extending in the horizontal direction along a corresponding support shelf;

article transport devices with each article transport device configured to travel along a corresponding travel path and to transfer an article to and from a support shelf that is associated with the corresponding travel path;

first optical communication devices with a first optical communication device provided in one end area, along a longitudinal direction, of each of the travel paths;

second optical communication devices with a second optical communication device provided to each of the article transport devices and configured to perform optical communication with a corresponding first optical communication device;

a main controller for controlling carry in operations and carry out operations of articles to or from the article storage rack using the article transport devices by causing the first optical communication devices that are associated with respective article transport devices to transmit control commands;

wherein the plurality of levels of support shelves provided to the article storage rack are divided into a plurality of groups that are located one above another in the vertical direction,

wherein each of the groups includes a plurality of the support shelves, and

wherein the main controller is configured to perform a temporally-divided light-emission control in which a plurality of the first optical communication devices are caused to emit light in a temporally divided manner such that there is only one first optical communication device that emits light in any one time period among the first optical communication devices that are associated with the support shelves that constitute each group.

2. The article storage facility as defined in claim 1 , wherein

if it is determined that two or more of the first optical communication devices, that belong to mutually different groups and that are in such a positional relationship that optical communication signals would interfere with each other if the two or more of the first optical communication devices are to emit light in a same time period, emit light in the same time period, the main controller performs an inter-group adjustment control in which mutually exclusive adjustment among the groups is performed such that there is only one first optical communication device that emits light in any one time period among the two or more of the first optical communication devices that are determined to emit light in the same period.

3. The article storage facility as defined in claim 2 , wherein

the main controller performs the inter-group adjustment control such that priority is given to light emission by the first optical communication device that belongs to a group that includes more support shelves that define the group than any other group.

4. A method of operating an article storage facility, the article transport facility including

an article storage rack including a plurality of levels of support shelves that are spaced apart from one another in a vertical direction, each support shelf being capable of storing a plurality of articles arranged in a row in a horizontal direction;

travel paths with a travel path provided for each level of the support shelves and extending in the horizontal direction along a corresponding support shelf;

article transport devices with each article transport device configured to travel along a corresponding travel path and to transfer an article to and from a support shelf that is associated with the corresponding travel path;

first optical communication devices with a first optical communication device provided in one end area, along a longitudinal direction, of each of the travel paths;

second optical communication devices with a second optical communication device provided to each of the article transport devices and configured to perform optical communication with a corresponding first optical communication device;

a main controller for controlling carry in operations and carry out operations of articles to or from the article storage rack using the article transport devices by causing the first optical communication devices that are associated with respective article transport devices to transmit control commands;

wherein the plurality of levels of support shelves provided to the article storage rack are divided into a plurality of groups that are located one above another in the vertical direction, and

wherein each of the groups includes a plurality of the support shelves,

the method of operating the article transport facility comprising the following step that is performed by the main controller:

a temporally-divided light-emission step in which a plurality of the first optical communication devices are caused to emit light in a temporally divided manner such that there is only one first optical communication device that emits light in any one time period among the first optical communication devices that are associated with the support shelves that constitute each group.

5. The method of operating an article storage facility as defined in claim 4 , wherein

the steps performed by the main controller further comprising the following step:

an inter-group adjustment step in which, if it is determined that two or more of the first optical communication devices, that belong to mutually different groups and that are in such a positional relationship that optical communication signals would interfere with each other if the two or more of the first optical communication devices are to emit light in a same time period, emit light in the same time period, mutually exclusive adjustment among the groups is performed such that there is only one first optical communication device that emits light in any one time period among the two or more of the first optical communication devices that are determined to emit light in the same period.

6. The method of operating an article storage facility as defined in claim 5 , wherein

in the inter-group adjustment step, priority is given to light emission by the first optical communication device that belongs to a group that includes more support shelves that define the group than any other group.