Transportation vehicle system
A plurality of intra-bay routes and an inter-bay route between the intra-bay routes are defined as a logic bay, and the minimum number of allocated transportation vehicles is determined based on the unit of each logic bay.
1. A transportation vehicle system comprising a plurality of intra-bay routes and an inter-bay route connected to the intra-bay routes for allowing transportation vehicles to travel along each route:
the system further comprising at least a logic bay comprising and defined as adjacent intra-bay routes and a portion of the inter-bay route connecting the adjacent intra-bay routes;
logic bay control means for assigning transportation instructions to the transportation vehicles in the logic bay to maintain a number of the transportation vehicles in the logic bay to a minimum number or more; and
a buffer for a transportation article along said portion of the inter-bay route, the logic bay control means for dividing a transportation instruction for transportation from an inside of the logic bay to an outside of the logic bay into a transportation instruction for transportation from an intra-bay route in the logic bay to the buffer along said portion of the inter-bay route and a transportation instruction from the buffer to the outside of the logic bay, when the number of the transportation vehicles in the logic bay is the minimum number, for allowing the transportation vehicle in the logic bay to execute only the transportation instruction for transportation to the buffer.
2. The transportation vehicle system according to claim 1 further comprising means for changing the logic bay in a number of the adjacent intra-bay routes and said portion of the inter-bay route or the minimum number of the transportation vehicles, according to the number of transportation instructions for transportation starting from the inside of the logic bay.
3. A method of controlling a transportation vehicle system comprising a plurality of intra-bay routes and an inter-bay route connected to the intra-bay routes for allowing transportation vehicles to travel along each route, the method including the steps of:
defining adjacent intra-bay routes and a portion of the inter-bay route connecting the adjacent intra-bay routes as a logic bay; and
assigning transportation instructions to the transportation vehicles in the logic bay to maintain a number of the transportation vehicles in the logic bay to a minimum number or more;
providing a buffer for a transportation article alone said portion of the inter-bay route; and
dividing a transportation instruction for transportation from an inside of the logic bay to an outside of the logic bay into a transportation instruction for transportation from an intra-bay route in the logic bay to the buffer along said portion of the inter-bay route and a transportation instruction from the buffer to the outside of the logic bay, when the number of the transportation vehicles in the logic bay is the minimum number, for allowing the transportation vehicle in the logic bay to execute only the transportation instruction for transportation to the buffer.
4. The method of controlling a transportation vehicle system according to claim 3 , further comprising the step of:
changing the minimum number of the transportation vehicles, according to the number of transportation instructions for transportation starting from the inside of the logic bay.