Automated Storage and Retrieval System (AS/RS)
The ARUP AS/RS, which was placed in daily service on December 18, 2003, is an all-robotic storage system that can hold up to 5220 stainless steel trays of specimens on indexed shelf locations. Although the AS/RS is primarily used for specimen tubes, many other types of specimen containers are also stored. The maximum capacity of the system is more than 2.3 million specimens. A narrated video of the AS/RS in operation can be viewed by clicking here.
Built by Daifuku America Corporation, the world’s largest manufacturer of such systems, the AS/RS is contained entirely within the largest clinical laboratory freezer in the US. This -20°C freezer is 60x30x26 feet (two stories) in size and uses only dehumidified air so that it is entirely frost-free. At the front of the freezer is a large (one-story) refrigerator (+4°C), which also has dehumidified air. The refrigerator serves as anteroom to the freezer. When the automated doors to the freezer are opened for trays going in or out, they only open to the refrigerator, so moisture or warm air cannot enter the freezer. Only the refrigerated anteroom opens to the ambient laboratory environment. In addition, the entire freezer system, refrigerated anteroom, AS/RS, and all associated computers are on ARUP’s emergency power system. The refrigerated anteroom also houses the inbound and outbound conveyors for the AS/RS and a separate robotic AS/RS Sorter built by Yaskawa Motoman (see below). A three-dimensional drawing of the freezer, refrigerated anteroom, AS/RS, AS/RS Sorter, and conveyors can be viewed by clicking here.
Conveyors transport stainless steel trays of specimens from an outside entry point through the refrigerator to one of the AS/RS’s three robotic shuttle cranes inside the freezer. Each shuttle crane can transport up to two trays at a time to shelf locations and retrieve two trays from other locations with an average cycle time of 50 seconds. The three shuttle cranes combined can retrieve as many as 210 trays per hour. The retrieved trays are placed on the outbound conveyor system. The trays exit the freezer into the refrigerator where the conveyor branches in two directions. One branch takes trays of tubes to the Yaskawa Motoman AS/RS Sorter, which picks individual tubes requested for retrieval out of the trays and places them in small plastic racks that hold up to 30 tubes each. Since the deck of the AS/RS Sorter holds up to 39 racks, checkout requests can be built for up to 39 employees at the same time. With an overall retrieval time of less than 2.5 minutes, tubes requested by employees in their own work areas are typically in a rack waiting for the employee when he or she arrives at the checkout station.
Only trays with tubes that have been robotically loaded by a storage autosorter are routed to the Yaskawa Motoman AS/RS Sorter for automated retrieval. Other trays, which contain urine bottles, fecal specimens, bagged specimens, or tubes that are too tall, too short, or too fat to be placed in trays robotically, are manually loaded with these containers. When there are requests to retrieve these specimens, the trays exit the AS/RS on a conveyor that comes out to a manual retrieval area instead of diverting to the Yaskawa Motoman AS/RS Sorter for automated retrieval.
The Daifuku America AS/RS and the Yaskawa Motoman AS/RS Sorter operate by using computers and software provided by those companies. However, those computers are interfaced to ARUP’s ESP system and ESP has primary control over all storage and checkout activities, so most employees only need to use ESP. However, in ARUP’s Automated Specimen Management (ASM) group, operators have been trained to use these other computer systems if necessary.